WO2010067576A1

WO2010067576A1 - Pipe having grooved inner surface, apparatus for producing the same and method for producing the same

Info

Publication number: WO2010067576A1
Application number: PCT/JP2009/006674
Authority: WO
Inventors: 尹栄徳; 釣弘太郎; 橋爪利明; 正武家和昭
Original assignee: 古河電気工業株式会社; 田口忠
Priority date: 2008-12-08
Filing date: 2009-12-07
Publication date: 2010-06-17
Also published as: KR101278827B1; MY167025A; KR20110089189A; CN102245323B; CN102245323A

Abstract

Provided is a pipe having a grooved inner surface, which has excellent thermal conduction properties, can be made compact and lightweight, and allows resources to be conserved. Also provided are a method and apparatus for producing this pipe having a grooved inner surface, which allow efficient and stable production thereof. The apparatus which is used for producing the pipe having a grooved inner surface is provided with: diameter-reducing means for drawing a base pipe in order to reduce the diameter thereof, and groove-forming means for forming a large number of grooves on the inner surface of the base pipe. If, for example, the angle of twist of a groove with respect to the centre axis of the pipe is β (º) and the apex angle of a fin which is formed between adjacent grooves is α (º), then β is between 30 and 60 and α is between 5 and 20. If the outer diameter is D (mm), the groove depth is H (mm), and the cross-sectional area with respect to the axial direction of the pipe is A_c (mm²), then D is no greater than 6, H is at least 0.07, and A_c < 0.8 × D.

Description

Internal grooved tube, manufacturing apparatus and manufacturing method thereof

The present invention relates to an internally grooved tube used as a heat transfer tube for a heat exchanger such as a refrigerator or an air conditioner, and a manufacturing method thereof.

Heat transfer tubes used in heat exchangers of heat pump equipment such as air conditioners and water heaters often use, for example, copper inner grooved tubes with inner surfaces grooved in order to improve heat exchange performance.

In recent years, in order to meet the demands for miniaturization and high efficiency of heat exchangers, the groove formed on the inner surface is deepened, the torsion angle (lead angle) of the groove is increased, the fins are sharpened, and the tube The performance of the heat exchanger is improved by manufacturing an internally grooved tube with a reduced wall thickness.

For example, Patent Document 1 below proposes a small-diameter heat transfer tube having an outer diameter of 3 to 6 mm, which is effective for downsizing heat exchange equipment. However, the workability of the groove is assumed to be performed by a conventional processing method. Therefore, the twist angle was small and the degree of performance improvement was small.

In addition, since the apex angle of the inner fin is large and it cannot be said that it has a sharp shape, the weight must be reduced (reducing the weight of the material used per unit length) to cope with the recent resource saving of metal materials. It was difficult.

Also, in Patent Document 2 below, an example of a high performance heat transfer tube having a deep inner groove depth is proposed, but it is intended for an outer diameter of 6 mm or more.

Patent Document 3 below proposes an example of a high performance tube having a deep inner groove depth and a large twist angle. Conventionally, a heat transfer tube having an outer diameter of about 7 mm, which has been generally used as a heat transfer tube for air conditioning. Is targeted.

As described above, in Patent Documents 2 and 3 described above, high performance is achieved by increasing the groove depth of the inner surface of the heat transfer tube or increasing the torsion angle, but this is effective for downsizing the heat exchanger. It cannot be applied to small-diameter heat transfer tubes with an outer diameter of 6 mm or less. The reason for this is that if the tubes have the same wall thickness but different diameters, the breaking load will be smaller for smaller diameter tubes. This is because it has been impossible to process exceeding the breaking load.

In such a method of manufacturing an internally grooved tube, there has been proposed a method using an auxiliary drawing device in which the metal pipe is sandwiched between a pair of caterpillars at a position between the drawing die and the pressing means. (See Patent Document 4). This makes it easy to produce an internally grooved metal tube with a small outer diameter, a thin wall, a deep groove on the inner surface, or a large twist angle (lead angle) with respect to the tube axis without causing the metal tube to break. It is supposed to be possible.

Further, in order to correspond to the high accuracy of the inner surface grooved tube, the diameter reducing means for reducing the diameter of the raw tube on the base movable in the drawing direction with respect to the drawing means for pulling out the grooved inner surface grooved tube, Auxiliary drawing device, grooving means composed of drawing dies and floating plugs, and finishing processing device that finishes the outer surface of grooved reduced diameter pipe are fixed, and the drawing means pulls the grooved inner grooved tube An apparatus for manufacturing an internally grooved tube having a base load detection device that detects a load applied to a base that moves relative to the drawing means has been proposed (see Patent Document 5).

In Patent Document 5, an auxiliary pulling device for assisting pulling of a pipe by a pulling means, a pulling force detecting means for detecting a pulling force, and a pulling force for the raw pipe based on a detection value of the pulling force detecting means are set as targets. An apparatus for manufacturing an internally grooved pipe provided with a control means for controlling the apparatus so as to be within a range and a manufacturing method using the manufacturing apparatus have been proposed.

However, in Patent Document 5, the target load value at which the processing load detected by the pulling force detection means is optimal in operating the manufacturing apparatus for the internally grooved pipe is clearly in relation to the cross-sectional area in the pipe axis direction. It has not been. For this reason, the auxiliary drawing device cannot be appropriately controlled, and a high-performance heat transfer tube cannot be manufactured efficiently and stably.

The apparatus for manufacturing an internally grooved tube of Patent Document 6 includes a diameter reducing die and a floating plug for reducing the diameter of the element tube, and forms a large number of grooves on the inner surface of the element tube on the downstream side in the drawing direction of the element tube. A grooved plug and a pressing tool are provided. Further, a wiper, a drawing device (intermediate drawing device), and an intermediate shaping die are provided between the reduced diameter die and the processing head along the drawing direction of the raw tube in order to prevent breakage of the raw tube during processing. This is a configuration provided.

Similarly, the manufacturing apparatus of the inner surface grooved pipe of Patent Document 5 also includes a diameter reducing means for reducing the diameter of the raw pipe, and a groove processing means for forming a plurality of grooves on the inner face of the raw pipe on the downstream side in the drawing direction of the raw pipe. A drawing means is also provided which also serves as a take-up drum for winding the processed inner grooved tube. Furthermore, it is a structure provided with the auxiliary | assistant extraction apparatus (intermediate extraction apparatus) which assists the said extraction means, and the control means which controls the extraction force of the said extraction means and an auxiliary extraction apparatus so that it may be settled in a target range.

According to the apparatus for manufacturing an internally grooved tube disclosed in Patent Documents 5 and 6, it is possible to reduce the drawing load during processing by the intermediate drawing device and to suppress the breakage of the tube during the processing.

However, even if the entire tensile load can be reduced, if the tensile load fluctuates, it has not been possible to perform processing that sufficiently copes with such a load variation.

For example, in the manufacturing apparatus disclosed in Patent Document 6, a wiper is provided in order to prevent a pad that is in contact with the element pipe from sliding relative to the element pipe, or a groove shape of the pad is defined in the intermediate drawing apparatus. Although measures have been taken, load fluctuations can still occur.
JP-A-4-260792 JP-A-8-21696 JP 2001-241877 A Japanese Patent No. 2950289 JP 2008-87004 A JP 2008-36640 A

Therefore, the present invention is excellent in heat conduction performance, can be reduced in size and weight, and can achieve resource saving, and an inner grooved tube and such an inner grooved tube can be efficiently and stably provided. An object is to provide a manufacturing method and a manufacturing apparatus that can be manufactured.

In the internally grooved tube of the present invention, when the twist angle of the groove with respect to the central axis of the tube is β (degrees) and the apex angle of the fin formed between adjacent grooves is α (degrees), β is 30 to 60, α is 5 to 20, the outer diameter is D (mm), the groove depth is H (mm), and the cross-sectional area in the axial direction of the tube is A _C (mm ² ). 6 or less, H is 0.07 or more, and A _C <0.8 × D.

With the above-described configuration, the groove depth can be increased, the twist angle can be increased, the apex angle can be decreased, and the heat transfer performance can be increased as compared with the conventional internally grooved tube. Furthermore, weight reduction and resource saving can be achieved by reducing the cross-sectional area.
The inner grooved tube can be used as a high-performance and lightweight heat transfer tube to reduce the size and weight of the heat exchanger.

Furthermore, as an aspect of the present invention, the inner grooved tube can have an outer diameter D (mm) of 3 or more.

With the above configuration, the inner grooved tube can be used as a more preferable heat transfer tube for a heat pump device such as an air conditioner or a water heater.

Furthermore, as an aspect of the present invention, the inner grooved tube may have a groove depth H (mm) of 0.10 to 0.30.

Also, the manufacturing method of the inner surface grooved pipe of the present invention is the manufacture of the inner surface grooved pipe provided with a diameter reducing means for drawing out and reducing the diameter of the raw pipe and a groove processing means for forming a large number of grooves on the inner surface of the raw pipe. An apparatus is used.

The diameter-reducing means can be constituted by a diameter-reducing die having a die hole in which a mortar-like slope that is widened toward the upstream side, for example. A floating plug inserted into the raw tube can be disposed at a position corresponding to the die hole of the reduced diameter die.

The groove processing means is constituted by, for example, a grooved plug connected to the floating plug, and a rolling tool composed of a roller or a ball that presses the reduced diameter tube while planetarily rotating toward the grooved plug. be able to.

As an aspect of the present invention, an inner surface grooved tube manufacturing method includes a drawing device in which the inner surface grooved tube manufacturing apparatus also serves as a take-up drum that winds an inner surface grooved tube downstream of the groove processing means. Means, an auxiliary drawing means for drawing the blank tube between the diameter reducing means and the groove processing means, and supporting the diameter reducing means, the auxiliary drawing means and the groove processing means, and pulling out the installation portion. A movable means movable in a direction, a load detection means for detecting a machining load acting in accordance with the movement of the movable means relative to the installation portion, and the auxiliary pull-out based on the machining load detected by the load detection means The groove twisting angle with respect to the central axis of the pipe is β (degrees) using a manufacturing apparatus for an internally grooved pipe provided with a control means for controlling the means, and the top of the fin formed between adjacent grooves. When the angle is α (degrees), β is 30 Et 60, alpha is from 5 20, the outer diameter D (mm), the depth of the groove H (mm), when the cross-sectional area with respect to the axial direction of the pipe was _A C (mm ^2), D is 6 Hereinafter, the manufacturing method of the internally grooved pipe having H of 0.07 or more and A _C <0.8 × D, wherein the processing load is P (N), the axis of the pipe after passing through the groove processing means When the cross-sectional area with respect to the direction is A _C1 (mm ² ) and the breaking stress of the tube after passing the groove processing means is σ _M (N / mm ² ), P is 0.5 times (A _C1 × σ _M ). It is preferable to control the auxiliary pulling means so as to be between 0.9 and 0.9 times.

The drawing means can be constituted by a winding device such as a winding drum, for example, by drawing and winding the internally grooved tube obtained by processing the raw tube on the downstream side.

The auxiliary drawing means can be constituted by, for example, a device for assisting feeding by feeding the reduced diameter tube to the groove processing means by sandwiching the reduced diameter pipe with a belt or a pad.

The above manufacturing method makes it possible to obtain an internally grooved tube having a larger groove depth, a larger torsion angle, a smaller apex angle and a higher heat transfer performance than the conventional internally grooved tube. Furthermore, by reducing the cross-sectional area, it is possible to obtain a light-weight and resource-saving inner grooved tube.

Also, a high-performance and lightweight heat transfer tube can be obtained efficiently and stably, and the heat exchanger can be reduced in size and weight.

Here, P ≧ 0.5 × (A _C1 × σ _M ) is a slight variation in the driving force of the auxiliary pulling means when P <0.5 × (A _C1 × σ _M ). This is because the shape of the inner surface of the tube is easily changed, and the groove depth and the like are not constant.

P ≦ 0.9 × (A _C1 × σ _M ) means that when P> 0.9 × (A _C1 × σ _M ), the pulling force is reduced due to slight wall thickness fluctuation or pulling force fluctuation. It is because the case where the breaking load of the tube is exceeded occurs and the tube breaks.

In addition, the cross-sectional area A _C (mm ² ) of A _C <0.8 × D indicates that the tube is thinner than the conventional one, but if the tube is thin, the tube will buckle. It becomes easy and the grooving by the grooving means becomes difficult. And the larger the tensile force in the axial direction, the more difficult it is to deform in the circumferential direction, and thus the grooving process becomes more difficult.

On the other hand, according to the manufacturing method of the present invention, as described above, the auxiliary pulling means is controlled so that P is between 0.5 and 0.9 times (A _C1 × σ _M ). Thus, the load in the drawing direction is reduced, and it is possible to suppress the buckling in the circumferential direction even with a thin-walled pipe.

Here, the cross-sectional area with respect to the axial direction of the pipe after passing through the grooving means is not limited to the cross-sectional area _AC1 with respect to the axial direction of the primary finishing pipe after passing through the grooving means. It shall also include the cross-sectional area a _C with respect to the axial direction of the finishing tube subjected to additional machining of the pull or the like.
In addition, empty drawing is a process which mainly reduces the outer diameter without directly processing the inner surface of the pipe, and indicates, for example, a process of drawing through an empty drawing die.

Furthermore, as an aspect of the present invention, the outer diameter D (mm) is preferably 3 or more.
In heat transfer tubes of heat pumps such as air conditioners, pressure loss is important in addition to heat transfer performance. When the pressure loss increases, the load on the pump and compressor (compressor) for sending refrigerant increases, Since the performance is degraded, the outer diameter D (mm) is preferably 3 or more for practical reasons.

Furthermore, as an aspect of the present invention, the depth H (mm) of the groove can be 0.10 to 0.30.
Heat transfer tubes used for heat pumps such as air conditioners are pushed from the inside of the tube with a tool such as a mandrel in order to press the aluminum fins. At that time, the fins on the inner surface are crushed and about 0.01 to 0.02 mm. Lower. Considering this, the groove depth is desirably 0.1 mm or more.
Further, if the inner fin is too high, pressure loss increases and the material weight increases. Therefore, the groove depth H (mm) is preferably 0.3 or less.

Here, the auxiliary pulling means can be configured to include, for example, a pair of endless members (loop-shaped members) that sandwich the raw tube from both sides with respect to the axial direction. By rotating the endless member such as the tube, it is possible to assist the drawing by the drawing means of the tube.

The load detecting means can be constituted by means capable of detecting a load such as a load cell.
Examples of the load detected by the load detection means include a compression load, a tensile load, and a moment load.

The inner grooved tube can be formed of a material having excellent thermal conductivity such as copper, aluminum, or an alloy thereof.

As an aspect of the present invention, the inner surface grooved pipe manufacturing apparatus includes the diameter reducing means, the groove processing means, and a drawing means for pulling out the grooved inner surface grooved pipe in this order from the upstream side. A feed assisting means (the auxiliary pulling means) provided between the diameter reducing means and the groove processing means for assisting the feeding of the reduced diameter tube in the feed direction toward the groove processing means, the diameter reducing means and the feed An auxiliary means is fixed and a movable table is movable relative to the grooving means in parallel with the drawing direction of the drawing means, and the grooving means is fixed and parallel to the drawing direction with respect to the drawing means. A base that is relatively movable, a moving base load detection device that detects a load in the relative movement direction applied to the mobile base when the mobile base moves relative to the groove processing means, and the base Against the pulling means A base load detection device that detects a load in the relative movement direction applied to the base when the relative movement is performed, and a control unit that controls the operation of the feed assisting unit. An inner grooved pipe manufacturing apparatus configured to be movable relative to the base in the drawing direction is used, and the control means includes at least a feed assist speed of the feed assist means and a feed assist torque of the feed assist means. It is preferable that either one is a manufacturing method of an internally grooved tube in which one of them is adjusted based on the difference between the loads detected by the moving table load detecting device and the base load detecting device.

Further, as an aspect of the present invention, the feed assist speed adjusted by the control means is set to the first feed assist speed, and the feed assist torque adjusted by the control means is determined based on the correlation with the feed assist torque. Control can be performed with the second feed assist speed.

For example, the movable table and the base can be configured by a table having wheels on the bottom surface and capable of sliding freely.
The moving table load detection device and the base load detection device can be configured by an appropriate detector capable of detecting a load, such as a load cell.

Further, as an aspect of the present invention, using the above-mentioned inner surface grooved pipe manufacturing apparatus, a diameter reducing process for reducing the diameter of the raw pipe in the process of moving the raw pipe in the drawing direction, and forming a plurality of grooves on the inner face of the raw pipe During the grooving step, while performing the squeezing step and the grooving step, an intermediate drawing step is performed to pull out the element pipe reduced in the squeezing step, and the squeezing step is reduced to the sizing step. A die and a floating plug that is disposed in the base pipe and reduces the diameter of the base pipe together with the reduced diameter die, and the grooving step is pivotally connected to the floating plug in the base pipe, and a plurality of outer circumferences are provided. An internally grooved tube formed by a grooved plug formed with a groove and a pressing tool arranged to revolve around the tube axis while pressing the raw tube toward the grooved plug on the outside of the raw tube. a manufacturing method, the outer diameter D _o of the blank tube mm), the diameter _D 2 of the diameter die _{_{(mm), R D = {}} (D o -D 2) / D o} radial contraction rate of mother tube represented by _{× 100 (%) R D (} %) Is set to R _D ≦ 30, and the outer diameter D ₁ (mm) of the floating plug and the diameter D ₂ (mm) of the reduced diameter die are set to satisfy D ₁ −D ₂ ≧ 0.1. Is preferred.

As in the inner grooved tube manufacturing method, by setting the diameter reduction rate of the raw pipe to 30% or less in the diameter reducing means, the so-called chatter phenomenon in which the raw pipe slightly vibrates after being reduced in diameter by the diameter reducing means. Therefore, the load assistance for assisting the extraction load by the intermediate extraction means (the auxiliary extraction means) can be stabilized.
Specifically, if the diameter reduction ratio of the blank pipe is greater than 30%, the contact area between the blank pipe and the diameter reduction die increases, and the frictional resistance increases, so the processing load on the diameter reduction die increases, The thinning of the outer diameter of the tube is smaller than the diameter of the outlet of the reduced diameter die.

Furthermore, due to the thinning, the contact between the raw tube and the diameter-reducing die is not stable, and chattering is likely to occur, and the thickness is reduced. Vibration due to chattering is transmitted to the intermediate drawing means, and the outer diameter of the raw pipe is reduced by thinning. Therefore, the pressing force of the pad provided for holding the raw pipe in the intermediate drawing means becomes unstable. As a result, the load assistance in the intermediate drawing means becomes unstable.

Therefore, in the present invention, the diameter reduction rate of the raw tube is set to 30% or less in the diameter reducing means so that such a problem does not occur during processing.

Furthermore, the chatter phenomenon is more effectively achieved by setting the outer diameter D ₁ (mm) of the floating plug and the diameter D ₂ (mm) of the reduced diameter die so that D ₁ −D ₂ ≧ 0.1. Can be suppressed.
More specifically, when the difference in diameter (D ₁ -D ₂ ) between the floating plug and the reduced diameter die is 0.1 mm or less, the area where the floating plug and the reduced diameter die overlap is reduced.

Thus, the area where the floating plug and the reduced diameter die overlap is reduced, so that when the blank tube is pulled in between, the corner of the floating plug, more specifically, the outer peripheral surface of the floating plug Since the inner surface of the pipe strongly hits the boundary between the upstream non-tapered surface and the downstream tapered surface, the load on the floating plug becomes excessive. Reduced, load assist instability in the intermediate drawing machine tends to occur.

Therefore, in the present invention, D ₁ −D ₂ ≧ 0.1 is set so that such a problem does not occur during processing.

Furthermore, as an aspect of the present invention, the revolution direction of the pressing tool is set to be opposite to the rotation direction of the grooved plug (hereinafter referred to as “reverse direction”), and the processing pitch P of the pressing tool ( mm) can be set in a range of 0.2 ≦ P ≦ 0.7.

With this configuration, it is possible to stably manufacture an internally grooved tube having a groove with high processing accuracy.
This is because, when P is smaller than 0.2 mm, it has been confirmed from experience that it is difficult to form a groove on the inner surface of the raw tube even if the load assistance by the intermediate drawing means is increased. On the other hand, if it is larger than 0.7 mm, the tensile load is not stable and the fluctuation becomes large.

In order to further stabilize the load assistance by the intermediate drawing means and increase the groove machining accuracy, the revolution direction of the pressing tool is set in the reverse direction, and the machining pitch P is set to P ≧ 0.2. It is better to set it as small as possible.
In detail, when giving priority to the processing in which the processing accuracy of the groove is higher than the productivity of the internally grooved tube, the processing pitch P is within the range of 0.2 ≦ P ≦ 0.7, for example, 0 .2 ≦ P ≦ 0.4 is preferable.

On the other hand, in order to increase the productivity of the internally grooved tube, it is better to set the revolution direction of the pressing tool in the reverse direction and to set the machining pitch P large in a range satisfying P ≦ 0.7. .
Specifically, in the case where the productivity of the internally grooved tube is given priority over the processing with higher groove processing accuracy, the processing pitch P is set within the range of 0.2 ≦ P ≦ 0.7, for example, 0 It is better to set 4 ≦ P ≦ 0.7.

Further, as an aspect of the present invention, the revolution direction of the pressing tool is set to the same direction as the rotation direction of the grooved plug (hereinafter referred to as “positive direction”), and the processing pitch P of the pressing tool ( mm) can be set in a range of 0.2 ≦ P ≦ 0.4.

Even if the revolving direction of the pressing tool is the positive direction as in the above configuration, the inner surface fin is set by setting the machining pitch P (mm) to be in the range of 0.2 ≦ P ≦ 0.4. In this case, the hems of the slabs do not have any glazing, and the groove depth is deep and the machining accuracy is high.

Specifically, in order to manufacture an internally grooved tube having a deep groove on the tube inner surface, it is desirable that the revolving direction of the pressing tool is a positive direction. An unfilled portion of a material called “egre” is likely to occur at the bottom of the fin formed between the two. Further, the greater the processing pitch P is, the easier it is to generate the egress.

For this reason, in order to prevent deepening while forming a deep groove, it is desirable that the revolution direction of the pressing tool is a positive direction and 0.2 ≦ P ≦ 0.4.

In general, the thinner the pipe, the harder it is to form the fins, and the easier it is to break. However, the present invention can be applied regardless of the thickness of the pipe, including thin pipes. Therefore, the thinner the pipe is, the more effective the production conditions of the present invention.

In addition, according to the present invention, the shape of the inner surface is stable over the entire length of the long tube and can be processed without breaking, so that it can be applied regardless of the length of the raw tube, and the yield and productivity can be improved. it can.

Moreover, the manufacturing apparatus of the inner surface grooved pipe of the present invention is characterized by comprising a diameter reducing means for reducing the diameter of the raw pipe and a groove processing means for performing groove processing on the inner surface of the reduced diameter pipe. To do.

As an aspect of the present invention, the diameter reducing means, the groove processing means, and a drawing means for pulling out the grooved inner grooved tube are provided in this order from the upstream side, and between the diameter reducing means and the groove processing means. An apparatus for producing an internally grooved pipe provided with a feed assisting means for assisting feeding of the reduced diameter pipe in a feed direction toward the groove machining means, wherein the diameter reducing means and the feed assisting means are fixed. And a movable base that is movable relative to the groove processing means in parallel with the drawing direction of the pulling means, and the relative movement applied to the movable base when the movable base moves relative to the groove processing means. It is preferable that the manufacturing apparatus of the internally grooved tube provided with a moving table load detecting device for detecting a load in the moving direction.

Furthermore, as an aspect of the present invention, the groove processing means is fixed and is movable relative to the drawing means in parallel with the drawing direction, and the base is moved relative to the drawing means. A base load detecting device for detecting the load in the relative movement direction applied to the base, and a control means for controlling the operation of the feed assisting means, wherein the moving base is withdrawn from the base. And the control means adjusts the feed assist speed of the feed assist means based on the load detected by at least one of the moving table load detecting device and the base load detecting device. A feed auxiliary speed adjustment process to perform and a feed auxiliary torque adjustment process to adjust the feed assist torque of the feed assist means. Kill.

Furthermore, as an aspect of the present invention, the feed assist speed in the assist speed adjustment process is set to a first feed assist speed, and the feed assist torque adjustment process is determined based on a correlation with the feed assist torque. The adjustment processing can be performed with the two-feed auxiliary speed.

As an aspect of the present invention, the diameter reducing means and the groove processing means are provided along the drawing direction of the raw tube, and the diameter is reduced by the diameter reducing means between the diameter reducing means and the groove processing means. An intermediate drawing means for drawing out the raw pipe, and the diameter reducing means is constituted by a diameter reducing die and a floating plug disposed in the pipe and reducing the diameter of the raw pipe together with the diameter reducing die, and the groove processing A grooved plug that is rotatably connected to the floating plug in the element tube and has a plurality of grooves formed on the outer periphery, and while pressing the element tube toward the grooved plug on the outer side of the element tube. An inner grooved pipe manufacturing apparatus configured with a pressing tool arranged to revolve around a pipe axis, wherein the outer diameter D _o (mm) of the raw pipe and the diameter D ₂ (mm of the reduced die) _{_{by), R D = {(D}} o -D 2) / D } × 100 (percent) radial contraction rate _R D (%) of the mother tube represented by, set _{R D} ≦ 30 in the reduced diameter section, the outer diameter _D 1 of the said floating plug (mm), the diameter It is preferable to set the die diameter D ₂ (mm) so that D ₁ −D ₂ ≧ 0.1.

Like the inner grooved pipe manufacturing apparatus, by setting the diameter reduction rate of the element pipe to 30% or less in the diameter reducing means, the so-called chattering that the element pipe slightly vibrates after the diameter reduction by the diameter reducing means. The phenomenon is suppressed, and the load assist that assists the extraction load by the intermediate extraction means can be stabilized.
Specifically, if the diameter reduction ratio of the blank pipe is greater than 30%, the contact area between the blank pipe and the diameter reduction die increases, and the frictional resistance increases, so the processing load on the diameter reduction die increases, The thinning of the outer diameter of the tube is smaller than the diameter of the outlet of the reduced diameter die.

In addition, as an aspect of the present invention, a drawing means for drawing an internally grooved pipe which has been processed on the downstream side in the tube axis direction of the grooving means, and a drawing of the raw pipe on the upstream side in the pipe axis direction from the drawing means. It is preferable that the manufacturing apparatus of the internally grooved pipe provided with the processing related data detecting means for detecting the processing related data relating to the processing load generated in the pipe axis direction.

With the above configuration, it is possible to detect machining-related data related to the machining load generated in the pipe axis direction as the pipe is drawn, so that the pipe breaks on the upstream side in the pipe axis direction from the drawing means based on the machining-related data. Even so, it can be recognized that the disconnection has occurred before the grooved plug provided in the groove processing means is broken.

Therefore, measures such as stopping the apparatus can be taken quickly, and the grooved plug can be prevented from being directly pressed against the rolled ball by the groove processing means and being damaged.

The processing related data is, for example, the processing load measured by the diameter reducing means or the groove processing means, or the drawing load of the intermediate drawing means (the auxiliary drawing means), in other words, the motor load (driving force). Relevant load related data can be listed. Further, the machining-related data may be data such as a current value or a voltage value obtained by converting a machining load or a driving force into an electrical signal, or a differential value obtained by differentiating these values. The tendency shown by the graphed waveform may be used.

Further, as an aspect of the present invention, the machining-related data detection means includes a groove machining load measuring means for measuring the machining load in the grooving means and a reduced diameter machining load measuring means for measuring the machining load in the diameter reducing means. Of these, at least one can be configured.

When the machining-related data detection means is configured by the grooving load measuring means, it can be determined that a disconnection has occurred based on the change in the machining load at the grooving means.
When the processing-related data detection means is constituted by the reduced diameter processing load measuring means, it can be determined that a disconnection has occurred based on a change in the processing load at the reduced diameter means.

For this reason, even when a sizing die is installed on the downstream side of the grooving means, in both the grooving means and the squeezing means, the grooved plug is not affected by being delayed in the determination of the occurrence of disconnection. The occurrence of disconnection can be recognized before it breaks.

In particular, when the processing-related data detection means is configured by the diameter reducing load measuring means, the disconnection occurred even when a disconnection occurs between the groove processing means and the diameter reducing means. Is preferable in that it can be determined instantaneously.

Further, in both the groove machining means and the diameter reducing means, for example, a predetermined ratio before the machining load drops to the level of mechanical loss such as 20% with respect to the machining load during normal steady machining, for example. If it changes to, it can be judged as a disconnection.

Furthermore, as an aspect of the present invention, an intermediate drawing means for drawing an element pipe between the diameter reducing means and the groove processing means is provided, and the processing related data detection means is related to a drawing load of a motor of the intermediate drawing means. The load-related data detecting means for detecting the load-related data can be configured.

By providing the intermediate drawing means, it is possible to assist the drawing of the raw pipe by the drawing means, while the load variation on the diameter reducing means and the groove processing means tends to be large. Based on the load-related data detected by the related data detecting means, it can be recognized that the disconnection has occurred, and the grooved plug can be prevented from being damaged.

Furthermore, since the load-related data related to the drawing load (motor load) of the intermediate drawing means is detected and used for recognizing the disconnection, load measuring means such as a load cell and a torque gauge, Since no hardware such as a jig for installing the load measuring means is required, the disconnection detection can be easily performed using existing equipment.

In this case, since the drawing load itself of the intermediate drawing means always changes during the processing by the control, it may be difficult to recognize the occurrence of the broken tube. If a differential value or a difference value of the load is used, it is preferable in that the occurrence of the disconnection can be surely recognized because a significant variation is exhibited when the disconnection occurs.

When the differential value of the drawing load is used as the load-related data, the disconnection determining means, for example, the standard deviation (σ) in the distribution with a variation that causes the differential value of the drawing load to occur even during normal steady machining. If it fluctuates greatly exceeding a predetermined width, such as 5 times (5σ), it can be determined that the tube is broken.

As described above, the load-related data can include drawing load (motor load), data such as current value and voltage value (electric signal) corresponding to the load, differential values and difference values of these data, and the like.

Furthermore, the load-related data is not limited to the motor load, but may be a motor torque. In addition, the load-related data may include a transmission mechanism such as a pulley or a belt that is movable by the motor load of the intermediate drawing means. There is no particular limitation as long as it is data related to the motor load of the intermediate drawing means, including the angular) speed, the (angular) acceleration speed, or these differential values.

Furthermore, as an aspect of the present invention, a disconnection determining means for determining that a disconnection has occurred based on the processing related data detected by the processing related data detecting means can be provided.

The disconnection determination means can automatically determine that a disconnection has occurred based on the processing related data detected by the processing related data detection means. Therefore, it is possible to reliably stop and prevent breakage of the grooved plug.

Furthermore, in the present invention, it is determined by the disconnection determining means that the disconnection has occurred on the basis of the processing related data detected by the processing related data detecting means, using the manufacturing apparatus of the inner surface grooved pipe. The method for producing an internally grooved tube that stops processing is characterized by the following.

With the above configuration, it is automatically determined that a disconnection has occurred based on the processing-related data detected by the processing-related data detection means, and if it is determined that a disconnection has occurred, the grooved plug provided in the groove processing means is damaged. Since machining can be stopped before, the grooved plug can be reliably prevented from being damaged.

According to the present invention, an internally grooved tube that has excellent heat conduction performance, can be reduced in size and weight, and can realize resource saving, and such an internally grooved tube can be manufactured efficiently and stably. It is possible to provide a manufacturing method and a manufacturing apparatus that can be used.

Sectional drawing which shows the manufacturing apparatus of the inner surface grooved pipe | tube of Embodiment 1. FIG. Sectional drawing which shows a part which cut | disconnected the internal grooved pipe | tube of Embodiment 1 at right angle with respect to the pipe axis. Sectional drawing in the surface which passes along the pipe axis of the internally grooved pipe | tube of Embodiment 1. FIG. The block diagram which shows the structure of the internal grooved pipe manufacturing apparatus of Embodiment 2. FIG. Explanatory drawing explaining the load and force in the inner surface grooved pipe manufacturing apparatus of Embodiment 2. FIG. 9 is a flowchart showing the overall operation of the inner surface grooved pipe manufacturing apparatus of the second embodiment. Sectional drawing which shows the manufacturing apparatus of the inner surface grooved pipe of Embodiment 3. FIG. FIG. 6 is a configuration explanatory view of a diameter reducing means, in which the diameter reducing means of Embodiment 3 is partially shown in cross section. FIG. 9 is an operation explanatory view showing a state in which the diameter of a raw pipe is reduced by the diameter reducing means of Embodiment 3. Explanatory drawing explaining the processing pitch of the processing ball | bowl of Embodiment 3. FIG. Sectional drawing which shows a part of pipe inner surface which has the fin which the egle has generate | occur | produced. Explanatory drawing which shows a mode that an element pipe is diameter-reduced by the conventional diameter reducing means. Sectional drawing which shows the manufacturing apparatus of the inner surface grooved pipe of Embodiment 4A. Sectional drawing which shows the manufacturing apparatus of the inner surface grooved pipe of Embodiment 4B. Sectional drawing which shows the manufacturing apparatus of the inner surface grooved pipe of Embodiment 4C. Sectional drawing explaining the installation location of the processing load detection part installed in each manufacturing apparatus of Embodiment 4A, 4B and a prior art. Sectional drawing explaining the installation location of the process load detection part installed in the manufacturing apparatus of Embodiment 4C. The figure which showed the fluctuation of the processing related data before and after the occurrence of the disconnection in the form of a graph showing the state of the occurrence of the disconnection in the manufacturing apparatus of the comparative example. The figure which showed the fluctuation of the processing related data before and after the occurrence of the disconnection in the form of a graph showing the state of the occurrence of the disconnection in the manufacturing apparatus of the comparative example. The figure which showed the fluctuation of the processing related data before and after the occurrence of the disconnection in the form of a graph showing the state of the occurrence of the disconnection in the manufacturing apparatus of the comparative example. The figure which showed the fluctuation of the processing related data before and after the occurrence of the disconnection in the form of a graph showing the state of the occurrence of the disconnection in the manufacturing apparatus of the comparative example. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4A. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4A. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4A. The figure which showed the change of processing related data before and after the occurrence of a disconnection in the form of a graph showing the state of the occurrence of a disconnection in the manufacturing apparatus of Embodiment 4B. The figure which showed the change of processing related data before and after the occurrence of a disconnection in the form of a graph showing the state of the occurrence of a disconnection in the manufacturing apparatus of Embodiment 4B. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4C. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4C. The figure which showed the change of processing related data before and after the occurrence of disconnection in the form of a graph showing the state of occurrence of disconnection in the manufacturing apparatus of Embodiment 4C.

DESCRIPTION OF SYMBOLS 11 ... Internal grooved pipe 12 ... Internal grooved pipe manufacturing apparatus 13 ... Diameter reduction part 14 ... Groove processing part 16 ... Drawing apparatus 17 ... Auxiliary drawing apparatus 33 ... Movable stand 35 ... Load cell 45 ... Control device 50 ... Fixed stand 101 ... Inner grooved tube manufacturing device 120 ... Reducing device 130 ... Auxiliary feeding device 140 ... Groove processing device 160 ... Winding drum 171 ... Controller 176 ... Calculator 182 ... Upper movable table 184 ... Whole movable table 192 ... Upstream load detection 194 ... Overall load detector 201 ... Element tube 202 ... Reduced diameter tube 204 ... Inner grooved tube 311 ... Inner surface grooved tube 311a ... Element tube 312 ... Inner grooved tube manufacturing apparatus 313 ... Reduced diameter means 314 ... Groove processing Means 317 ... intermediate extraction part 322 ... reduced diameter die 323 ... floating plug 324 ... grooved plug 326 ... processed

balls

510A, 510B, 510C ... inner surface grooved pipe manufacturing apparatus 511 ... inside Grooved tube 511a ... Raw tube 513 ... Diameter reduction processing part 514 ... Groove processing part 516 ... Drawing

part

517, 545, 552 ... Processing related

data detection part

518, 546, 553 ... Control part 524 ... Grooved plug 541 ... Groove processing Load cell for load measurement 551 ... Intermediate drawing part P ... Processing load

(Embodiment 1)
An embodiment of the present invention will be described below with reference to the drawings.
The manufacturing method of the internally grooved tube 11 in this embodiment can be manufactured using a manufacturing apparatus 12 as shown in FIG.

In addition, FIG. 1 is explanatory drawing of the manufacturing apparatus 12 of an inner surface grooved pipe | tube in this embodiment.

The manufacturing apparatus 12 has a reduced diameter portion 13, an auxiliary drawing device 17, a groove processing portion 14, and a finishing processing portion 15 in order from the upstream side to the downstream side in the drawing direction (drawing direction) (X direction in FIG. 1). The drawing device 16 is further provided on the downstream side, and the inner tube 11a is manufactured by continuously processing the raw tube 11a with these configurations.

Specifically, the manufacturing apparatus 12 includes a diameter-reduced portion 13 that draws and reduces the diameter of the raw tube 11 a, a groove processed portion 14 that forms a large number of grooves on the inner surface of the raw tube 11 a, and a downstream side of the groove processed portion 14. It comprises a drawing device 16 that also serves as a winding drum 36 for winding the machined inner grooved tube 11, and an auxiliary drawing device 17 that draws the raw tube 11 a between the reduced diameter portion 13 and the groove processing portion 14. ing.

Further, the manufacturing apparatus 12 is movable with respect to the fixed base 50 so as to be movable in the drawing direction, the movable base 33 supporting the reduced diameter portion 13, the auxiliary drawing device 17 and the groove processing portion 14, and the fixing of the movable base 33. The load cell 35 detects a processing load P acting in accordance with the movement with respect to the table 50, and the control device 45 controls the auxiliary extraction device 17 based on the processing load P detected by the load cell 35.

Hereinafter, the structure of each part mentioned above is demonstrated.
The reduced diameter portion 13 constitutes a cylindrical die 22 for reducing the diameter of the passing raw tube 11a. The die 22 has a die hole 22a that opens toward the upstream side.

Further, the reduced diameter portion 13 is provided with a floating plug 23 inside the raw tube 11a. The floating plug 23 is formed so that a part of the outer peripheral surface in the axial direction is conical so as to be engageable with the die 22 via the raw tube 11a. Thereby, the floating plug 23 is rotatably engaged in the die 22 portion.

Further, the groove processing portion 14 includes a grooved plug 24 in which a plurality of spiral grooves are formed on the outer periphery inside the raw tube 11a.

The grooved plug 24 and the floating plug 23 are rotatably connected to each other via a connecting rod 25. Further, the groove processing portion 14 includes a plurality of balls 26, and the plurality of balls 26 are disposed around the tube axis while being pressed against the tube 11a outside the tube 11a. .

The grooved portion 14 is configured such that the grooved plug 24 abuts on the inner peripheral surface of the raw tube 11 a, the raw tube 11 a is pulled in the drawing direction while rotating around the axis, and pressed by a plurality of balls 26, thereby being pressed. A large number of parallel spiral grooves can be formed on the inner peripheral surface of the substrate.
The inner grooved tube 11 can be obtained by passing through the grooved portion 14.

The finishing portion 15 is provided with a diameter adjusting die 27, and the inner grooved tube 11 passes through the die hole 27 a of the diameter adjusting die 27, for example, by pressing the ball 26 in the groove processing portion 14. Processing to smooth the diameter of the tube surface distortion is performed.

The drawing device 16 includes a winding drum 36 and a winding motor M1, and winds around the winding drum 36 while pulling the inner grooved tube 11 by rotational driving of the motor M1.

The auxiliary drawing device 17 assists the drawing by the drawing device 16 by drawing the raw tube 11a in the drawing direction between the reduced diameter portion 13 and the groove processing portion 14. That is, the grooving by the grooving section 14 becomes a resistance when pulling out the raw tube 11a, and the pulling load during the grooving increases, but the pulling load applied to the raw tube 11a by the auxiliary drawing device 17 is increased. Can be dispersed.

The auxiliary drawing device 17 includes a pair of

belts

42a and 42b arranged on the upper and lower sides or the left and right sides with respect to the raw tube 11a. Each of the

belts

42a and 42b is formed in a loop shape (endless shape), and is stretched around the pulley 43 so as to be rotatable by the rotational drive of the motor M2. The

belts

42a and 42b are configured in a caterpillar type in which a plurality of pads 44 are continuously provided along the length direction on the outer peripheral surface.

The pair of

belts

42a and 42b in the auxiliary pulling device 17 is desired to have a pressing force of the raw tube 11a by the pad 44 of, for example, 0.3 MPa from the viewpoint of obtaining a sufficient pulling force and preventing deformation of the raw tube 11a. It is provided on each side with respect to the element tube 11a so as to be kept at the pressing force of.

Although not shown in the drawing, the pad 44 has a pad groove 44a having a circular cut surface in the connecting direction of the plurality of pads 44 at the contact portion with the outer surface of the base tube 11a after being reduced in diameter by the reduced diameter portion 13. Forming.
In addition, you may provide the wiper for removing the oil film and foreign material adhering to the outer surface of the element | tube 11a in the upstream of the said auxiliary extraction apparatus 17 (not shown).

The movable table 33 is installed on the fixed table 50 via a plurality of wheels 33a so as to be movable in the drawing direction or the opposite direction with respect to the fixed table 50. The part 14, the finishing part 15, and the auxiliary drawing device 17 are installed in a state of being accommodated in the box 32.

The load cell 35 is provided on the fixed base 50 and at the downstream end portion of the movable base 33 in the drawing direction so as to detect the processing load P received from the movable base 33 according to the pulling force of the raw tube 11a.

The control device 45 receives a load detection signal S _{in obtained} by converting the machining load P detected by the load cell 35 into an electrical signal, and outputs a control signal S _out for controlling the driving of the motor M2 of the auxiliary drawing device 17 according to the control program. To do.

Further, although not shown, the control device 45 temporarily stores an arithmetic unit (CPU) for executing signal analysis processing and arithmetic processing, a hard disk for storing necessary control programs, and the load detection signal S _in. In addition, an input unit such as a keyboard for inputting control parameters and a display unit such as a monitor can be appropriately provided.

The manufacturing method of the inner surface grooved tube 11 in the present embodiment is performed using the inner surface grooved tube manufacturing apparatus 12 described above.
Specifically, in the manufacturing method of the internally grooved tube 11 in the present embodiment, when the internally grooved tube 11 after passing through the sizing die 27 is a primary finish tube, the axial cross-sectional area of the primary finish tube is A _C1 (mm ² ) When the breaking stress of the primary finish pipe is σ _M (N / mm ² ), the auxiliary drawing is performed so that the processing load P is between 0.5 and 0.9 times (A _C1 × σ _M ). This is a method of manufacturing a primary finished tube of a desired shape by controlling the speed of the motor M2 of the device 17.

Thus, the control of the speed of the motor M2 of the auxiliary pulling device 17 so as to be between P ≧ 0.5 × (A _C1 × σ _M ) is P <0.5 × (A _C1 × σ _M ), The shape of the inner surface of the tube is likely to change due to slight fluctuations in the driving force of the auxiliary drawing device 17, and the groove depth and the like are not constant.

It is P> 0.9 × (A _C1 × σ _M ) that controls the speed of the motor M2 of the auxiliary drawing device 17 so that P ≦ 0.9 × (A _C1 × σ _M ). This is because the tube breaks due to slight wall thickness variations in the tube and fluctuations in the pulling force.

2 and 3, the outer diameter D is in the range of 3 mm to 6 mm, and the depth H of the groove 2 is 0.07 mm to 0.10 mm. To 0.30 mm, the twist angle β of the groove 2 with respect to the central axis of the tube is in the range of 30 to 60 degrees, and the apex angle α of the fin 1 formed between adjacent grooves 2 is from 5 degrees. When the cross-sectional area with respect to the axial direction of the pipe is A _C1 (mm ² ) in the range of 20 degrees, the internally grooved pipe 11 satisfying A _C1 <0.8 × D can be manufactured.
Note that A _C1 <0.8 × D indicates that the tube is thinner than the conventional one.
Assuming that the average thickness when the fins 1 are leveled and the grooves 2 are eliminated without changing the cross-sectional area is t ′ mm, when the thickness is sufficiently thin, A _c ≈πDt ′ For example, in order to realize t ′ <0.255, the cross-sectional area needs to satisfy the relationship of A _C <0.8 × D as described above. Because there is.

Moreover, when the wall thickness of the pipe is smaller than the conventional one, such as A _C <0.8 × D, processing becomes difficult. This is not only because the breaking load is reduced simply by reducing the cross-sectional area, but also because there are problems specific to grooving as described below.

That is, when the wall thickness is reduced, the tube wall tends to buckle in the ball revolving direction, and the material constituting the tube escapes radially outward before a portion of the tube wall is filled in the plug groove. Because.

In particular, in the conventional processing, the load applied in the drawing direction of the pipe increases, but as the axial tensile force increases, the deformation in the circumferential direction becomes difficult and the groove processing becomes difficult.

On the other hand, according to the manufacturing method of the inner surface grooved tube 11 described above, the load in the drawing direction applied to the tube is reduced by the control described above, and even when grooving a thin wall tube, It becomes possible to suppress circumferential buckling.

As described above, the inner grooved tube 11 can be a heat transfer tube having a larger groove depth, a larger torsion angle, a smaller apex angle, and a higher heat transfer performance than the conventional technology. Furthermore, by reducing the cross-sectional area, a heat transfer tube that is lightweight and resource-saving can be obtained. Further, by using such a high-performance and lightweight heat transfer tube, the heat exchanger can be made small and light.

In the above-described embodiment, the method for controlling the speed of the motor M2 of the auxiliary extraction device 17 by the control device has been described. However, not only the speed is controlled as a control parameter, but also the acceleration, torque, rotation angle, Alternatively, a plurality of these may be controlled as control parameters.

Further, FIG. 1 shows an example in which one motor M2 is attached to drive the auxiliary pulling device 17, but two motors may be attached to the left and right for operation.
In such a case, by using a motor that can follow the target operation control value such as a servo mechanism, the machining load P at the time of machining the internally grooved tube having the difficult-to-break shape as in the present invention is generated. This makes it possible to control in more detail and is effective in stabilizing the operation of the equipment.

Furthermore, the manufacturing method of the present invention only needs to be a method for controlling at least the auxiliary drawing device 17. For example, P is between 0.5 and 0.9 times (A _C1 × σ _M ). For example, both the auxiliary drawing device 17 and the drawing device 16 may be controlled.

Then, the performance comparison experiment implemented about the inner surface grooved pipe 11 comprised by the said method is demonstrated.
First, each elementary tube 11a was subjected to an internal groove processing apparatus under the appropriate conditions shown below, and a processing experiment was performed to produce a primary finish tube as an internal grooved tube.
In this experiment, the outer diameter D, the number of grooves, the bottom thickness t, the groove depth H, the torsion angle β, the apex angle α, the groove bottom width W ₁ , the mountain bottom width W ₂ , the groove bottom width W ₁ and the groove depth. Using the ratio of H and the cross-sectional area A _C1 (refer to FIG. 2) with respect to the axial direction as parameters, the inner grooved tube 11 of Examples 1 and 2 as shown in Table 1 below and Comparative Example 1 as a comparison between them Attempts were made to manufacture the inner grooved tube of No.4.

Specifically, for each of Examples 1 and 2 and Comparative Examples 1 to 4, a plurality of copper tubes (element tubes 11a) having an outer diameter of 8 mm and a smooth inner surface are prepared as processing raw materials, and processing is performed with a target of continuous 1000 m or more. Was performed five times, and a processing yield experiment was performed to compare the number of times 1000 mm or more could be processed without breaking.

In the first and second embodiments, the processing load P is 0.5 × (A _C1 × σ _M ) ≦ P ≦ 0. It is manufactured by a processing method for controlling the speed of the motor M2 of the auxiliary drawing device 17 so as to be 9 × (A _C1 × σ _M ).
In Examples 1 and 2, experiments were performed with the target pull-out loads set to 1200 N and 700 N, respectively.

On the other hand, in the comparative examples 1 and 2, it processes using the manufacturing apparatus 12 mentioned above, However, It manufactures by the setting from which the process load P remove | deviated from the conditions of this invention.
In Comparative Examples 1 and 2, experiments were performed with the target pull-out loads set to 1250 N and 600 N, respectively.

Comparative Examples 3 and 4 were performed by the method for manufacturing an internally grooved tube disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2001-241877). That is, in the comparative examples 3 and 4, the auxiliary drawing device 17 is not provided, and the manufacturing is performed using a manufacturing device that draws the raw tube 11a only with the drawing device.

Table 1 shows the results of the primary finishing tube processing experiment for each of Examples 1 and 2 and Comparative Examples 1 to 4. *

As can be seen from this result, in Examples 1 and 2, the apparatus configuration 12 of the present invention was used, and P was controlled between 0.5 times and 0.9 times (A _C1 × σ _M ). As a result, it was possible to stably process the internally grooved tube having the shape shown in Table 1 in all 5 out of 5 tests.

When the apex angle of the primary finish tube is smaller than 16 degrees, it is necessary to form the groove of the grooved plug 24 in a thin shape, and the thin groove of the grooved plug 24 cannot be filled with the tube meat. Becomes difficult.
Therefore, it can be said that the manufacturing method of the present invention capable of processing the apex angle at 16 degrees as in Examples 1 and 2 is particularly effective.

On the other hand, in Comparative Examples 1 and 2, it was possible to process without problems during the 5 times of machining, 3 times and 1 time, respectively, and the yield decreased in both cases. From this result, it became clear that when the range of the processing load P deviated from the conditions of the present invention, the stability of the processing decreased, and the effectiveness of the manufacturing method of the present invention could be verified.

In Comparative Example 3, it was possible to process all five times without breaking. For example, the outer diameter D is 8 mm larger than 6 mm, the apex angle α is 23 degrees larger than 20 degrees, and the cross-sectional area A _{C1 with} respect to the axial direction is Was larger than 0.8D to 7.6 mm ² , and the shape of the present invention as in Examples 1 and 2 was not obtained.

In Comparative Example 4, the same manufacturing apparatus as in Comparative Example 3 was used, and in particular, an attempt was made to process the outer diameter D to 6 mm, which was the same as in Examples 1 and 2. It was 0 times, and all of them were broken immediately after starting the processing, and the processing could not be continued.

Subsequently, the primary finish pipes of Examples 1 and 2 and Comparative Example 3 obtained in the above-described processing experiments are each pulled by a blanking die (not shown) and transmitted as a final finish pipe having a desired outer diameter. An emptying experiment was conducted to obtain a heat tube.

Specifically, empty drawing is a method in which the primary finish pipe is pulled through a die without directly processing the inner surface of the primary finish pipe, and the outer diameter is reduced and the wall thickness is reduced by the empty drawing. Slightly decreases. Further, the torsion angle decreases as it extends in the longitudinal direction.
In general, empty drawing is not performed if the primary finish pipe has a desired outer diameter, but is performed on the primary finish pipe when the primary finish pipe is larger than the desired outer diameter. In order to evaluate the later tube shape, a blanking experiment was performed on Example 1 or 2 and Comparative Example 3.

Thereby, the heat transfer tubes of Example 3 and Comparative Example 5 as shown in Table 2 below can be manufactured.

In Example 3, the primary finish tube of Example 1 or 2 was evacuated to reduce the outer diameter to 5 mm. In Comparative Example 5, the primary finish tube of Comparative Example 3 was evacuated and reduced in diameter to 7 mm in outer diameter.

Here, the ratio of the outer diameter and the cross-sectional area does not exactly match in the primary finishing pipe and the final finishing pipe that has undergone empty drawing, but in the scope of implementation, the diameter reduction rate of the empty drawing (the reduction rate of the outer diameter) is It is about 10 to 20%, and within this range, A _C1 / D ₁ ≈A _C / D.
A _C1 and D ₁ indicate the cross-sectional area and outer diameter in the axial direction of the primary finish pipe, respectively, and A _C and D indicate the cross-sectional area and outer diameter in the axial direction of the final finish pipe, respectively.

As can be seen from Table 2, in Example 3, the outer diameter D is 5 mm which is 3 mm or more and 6 mm or less, and the depth H of the groove 2 is 0.07 mm or more and 0.15 mm which is 0.10 mm to 0.30 mm. The twist angle β of the groove 2 with respect to the central axis of the tube is 40 degrees, which is 30 degrees to 60 degrees, and the apex angle α of the fin 1 formed between the adjacent grooves 2 is 2 degrees to 20 degrees. is 10 degrees, the heat transfer tube is obtained for satisfying the desired shape of the cross-sectional area a _C with respect to the axial direction is smaller 3.8 mm ² next than 0.8 times the outer diameter D, sinking after the invention of the tube It was.

On the other hand, Comparative Example 5 is obtained by emptying Comparative Example 3 as a primary finish pipe as described above. For example, Comparative Example 5 deviates from a desired shape in that A _C1 > 0.8D ₁ or the like. Even when 3 was emptied, it could not be processed into the desired shape (A _C > 0.8D).

This is because if the diameter reduction ratio due to idling is too large, the torsion angle becomes small or the fin 1 is divided, and there is a limit to the diameter reduction ratio that can be reduced by idling.
In Example 3 and Comparative Example 5, the heat transfer performance was also evaluated as shown in Table 2. The heat transfer performance of Example 3 is shown as relative heat transfer performance when the value of the heat transfer coefficient in the condensing tube of Comparative Example 5 is 100.

The heat transfer coefficient in the condensation tube used for calculating the heat transfer performance is measured by the following measurement method.
Each of the sample tubes is inserted as an inner tube of a double-tube heat exchanger sample installed horizontally, and the refrigerant (R410a) flows into the samples, and the double tube between the outer tube and the inner tube is inserted. Cooling water was allowed to flow in the pipe portion so as to counteract the refrigerant, and the refrigerant was cooled by heat exchange between the cooling water and the refrigerant.

From the heat exchange amount at that time, the heat transfer rate in the tube (condensation heat) at a refrigerant mass flow rate of 300 kg / m ² sec was measured (measured based on the tube outer surface reference).

As shown in Table 2, in Example 3 of this invention, it was set to 137 and the heat-transfer performance higher than the comparative example 5 was obtained.
In addition, since the heat transfer coefficient in the condensing tube also depends on the diameter, originally, Example 3 and Comparative Example 5 should compare and evaluate the heat transfer performance between those having the same diameter. In the manufacturing method of Comparative Example 5 (that is, Comparative Examples 3 and 4), since a small-diameter tube having an outer diameter D of 6 mm or less as in the present invention cannot be manufactured, Table 2 compares pipes having different diameters. It shows heat transfer performance.

Finally, Examples 4 to 8 as shown in Table 3 are manufactured as final finished pipes by the manufacturing method of the present invention described above, and the inner grooved pipes of the present invention are manufactured based on these Examples 4 to 8. The effectiveness of the method was verified.
In Example 6, the primary finish tube of Example 1 or 2 was used.

As shown in Table 3, each of Examples 4 to 8 had a desired shape satisfying the above-described range of the internally grooved tube 11 of the present invention, and could be processed with a high yield.

From the results shown in Table 3, according to the manufacturing method of the present invention, the groove depth is larger than that of the prior art, the twist angle is larger, and the apex angle is smaller. The inner grooved tube 11 can be manufactured, and it has been proved that a heat transfer tube having high heat transfer performance can be manufactured.

Furthermore, by reducing the cross-sectional area, light weight and resource saving can be achieved. This is a high-performance heat transfer tube that is ideal for heat exchangers of heat pump equipment such as air conditioners and water heaters.

In the performance evaluation experiment described above, the blanking was performed after the primary finish tube was created. However, the inner grooved tube of the present invention is not limited to the form in which the blanked tube is used as a product, but the primary finish tube. The form made into a product with the shape of is also included.

In the correspondence between the above-described first embodiment and the configuration of the present invention, the reduced diameter portion 13 of this embodiment corresponds to the reduced diameter means of the present invention.
The groove processing section 14 corresponds to the groove processing means,
The drawing device 16 corresponds to the drawing means,
The auxiliary extraction device 17 corresponds to auxiliary extraction means,
The movable part 33 corresponds to the movable means,
The load cell 35 corresponds to the load detection means,
The control device 45 corresponds to the control means,
The fixed base 50 corresponds to the installation part,
The primary finishing pipe or the final finishing pipe corresponds to the pipe after passing the grooving means, but the present invention is not limited to the configuration of the first embodiment, and many embodiments can be obtained. .

(Embodiment 2)
Next, the manufacturing apparatus 101 and manufacturing method of the inner surface grooved tube of Embodiment 2 will be described.
The inner surface grooved pipe manufacturing apparatus 101 includes a diameter reducing device 120 that reduces the diameter of the raw pipe 201 that is the object to be processed 200, a groove processing apparatus 140 that performs groove processing on the inner surface of the reduced diameter reduced pipe 202, and a groove A winding drum 160 for pulling out the processed inner grooved tube 204 is provided in this order from the upstream side.
An auxiliary feeding device 130 is provided between the diameter reducing device 120 and the groove processing device 140 to assist the feeding of the reduced diameter tube 202 in the feeding direction toward the groove processing device 140.

Further, in the inner surface grooved pipe manufacturing apparatus 101, an upstream movable base that is fixed to the diameter reducing apparatus 120 and the auxiliary feeding apparatus 130 and is relatively movable with respect to the groove processing apparatus 140 in parallel with the drawing direction of the winding drum 160. 182 is provided, and an upstream load detector 192 that detects a load in the relative movement direction applied to the upstream movable table 182 when the upstream movable table 182 moves relative to the groove processing device 140 is provided.

Further, the inner surface grooved pipe manufacturing apparatus 101 is provided with an entire movable stand 184 to which the groove processing apparatus 140 is fixed and which can move relative to the winding drum 160 in parallel with the drawing direction. The upstream movable table 182 is configured to be movable relative to the entire movable table 184 in the drawing direction.

Furthermore, an overall load detector 194 that detects a load in the relative movement direction applied to the entire movable table 184 when the entire movable table 184 moves relative to the winding drum 160 is provided.

Also, the inner surface grooved pipe manufacturing apparatus 101 includes a controller 171 and a calculator 176 that control the operation of the auxiliary feeder 130. Then, the controller 171 and the calculator 176 adjust the feed assist speed adjustment process for adjusting the feed assist speed of the auxiliary feed device 130 based on the load detected by at least one of the upstream load detector 192 and the overall load detector 194. And at least one of the feed assist torque adjustment processing for adjusting the feed assist torque of the auxiliary feed device 130.

The feed assist speed executed by the controller 171 and the calculator 176 in the assist speed adjustment process is the first feed assist speed. In the feed assist torque adjustment process executed by the controller 171 and the calculator 176, the feed assist torque and It adjusts with the 2nd feed auxiliary speed defined based on the correlation.

More specifically, the controller 171 and the calculator 176 include at least a feed assist speed adjustment process for adjusting the feed assist speed of the auxiliary feed device 130 and a feed assist torque adjustment process for adjusting the feed assist torque of the auxiliary feed device 130. Either one is adjusted based on the difference between the loads detected by the upstream load detector 192 and the overall load detector 194.

Example 9
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 4 is a configuration diagram illustrating a configuration of the inner surface grooved pipe manufacturing apparatus 101 according to the second embodiment. FIG. 4 shows a device used for processing, a device used for sensing, and a device used for control. FIG. 5 is an explanatory diagram for explaining the load applied to the material, the pulling force and auxiliary feed force used for processing, and the load to be detected in the inner surface grooved pipe manufacturing apparatus 101.

The apparatus used for processing will be described. From the upstream side to the downstream side, the diameter reducing device 120, the auxiliary feeding device 130, the groove processing device 140, and the finishing device 150 are arranged so that their processing parts are horizontal and straight. A take-up drum 160 that is arranged in order and that further draws and unwinds the tube 201 in a straight line is provided downstream thereof. The material of the raw tube 201 to be processed can be a metal having excellent thermal conductivity, such as copper, aluminum, or an alloy thereof.

The diameter reducing device 120 includes a gap between a diameter reducing die 121 that presses the periphery of the cylindrical pipe 201 inwardly and a floating plug 111 disposed inside the raw pipe 201. It is a device that reduces the diameter through.

The diameter-reducing die 121 is provided with a die hole 122 in which a mortar-shaped slope that is widened toward the upstream side is formed. The floating plug 111 is formed in a size larger than the minimum radius portion of the die hole 122 and slightly smaller than the inner peripheral size of the element tube 201, and is inserted into the element tube 201 in a free state. For this reason, when the base tube 201 is pulled out while being reduced in diameter by the die hole 122 of the reduced diameter die 121, the floating plug 111 is not pulled out together.

Further, the surface of the floating plug 111 facing the die hole 122 is formed as a truncated cone-shaped inclined surface. Thereby, the inner surface of the raw tube 201 whose diameter is reduced by pressing the outer peripheral surface with the die hole 122 can be pressed, and the diameter reduction processing can be stabilized.

The raw tube 201 supplied from the upstream side is reduced in diameter by the diameter reducing device 120 to become a reduced diameter tube 202.
At the time of the diameter reduction processing, the diameter reduction drawing load R3 is applied to the raw tube 201 as shown in FIG.

The auxiliary feeding device 130 includes a pressing device 131, a mounting plate 132, a pulley 133, and a belt 134.
The pressing device 131 presses the belt 134 together with the mounting plate 132 toward the reduced diameter tube 202 (see FIG. 4).

The attachment plate 132 is attached to the upstream machine casing 102 so as to be movable up and down (movable in a direction perpendicular to the drawing direction), and rotatably supports a pair of pulleys 133 arranged in the drawing direction. In this pair of pulleys 133, an endless belt 134 is stretched without slack, and the belt 134 is rotated by the driving force of the motor M2 that is a vector motor.
The belt 134 is formed in an endless loop shape, and a plurality of pads 135 are continuously arranged on the outer periphery. The pad 135 is preferably made of a material harder than the base tube 201, and is made of, for example, tool steel.

The mounting plate 132 provided with the pulley 133 and the belt 134 is provided symmetrically in the vertical direction (symmetrical in the direction perpendicular to the drawing direction) with the reduced diameter tube 202 interposed therebetween. Furthermore, the pressing device 131 is also provided vertically symmetrically. As a result, the upper and lower pressing devices 131 press the upper and lower pressing devices 131 toward the reduced diameter tube 202, and the reduced diameter tube 202 is sandwiched between the pads 135.

The auxiliary feeding device 130 performs an auxiliary feeding operation under the control of the configuration and the controller 171. In other words, the pressing device 131 holds the reduced diameter tube 202 from above and below with the pad 135 at a constant pressure at which the reduced diameter tube 202 is not excessively deformed. Then, the pulley 133 is rotated at a constant ratio by the rotational drive of the motor M2 according to the control of the controller 171, and the belt 134 is rotated along with this, and the material traveling direction (drawing) between the pad 135 and the reduced diameter tube 202 is rotated. Direction) feed friction force.

In the feed assist by the feed friction force, the auxiliary feed device 130 can apply the auxiliary feed force F2, that is, the auxiliary feed torque to the reduced diameter tube 202 as shown in FIG. For this reason, the speed of the pad 135 in the feeding direction is higher than or equal to the winding speed of the winding drum 160.

The groove processing device 140 includes a grooved plug 113, a processing head 141, a rolling tool 142, a pressing member 143, and a bearing 144.
The grooved plug 113 is inserted into the reduced diameter tube 202 in a free state, and is rotatably connected to the above-described floating plug 111 by a connecting rod 112. Thereby, it is comprised so that the position in the extraction direction of the grooved plug 113 may not move back and forth.

The processing head 141 is formed with a conical surface that expands toward the downstream. The inner diameter of the through hole including this conical surface is formed to be slightly larger than the outer diameter of the reduced diameter tube 202.
The pressing member 143 is formed in a ring shape and is rotatably attached by a bearing 144.

The rolling tool 142 is composed of a plurality of balls. The rolling tool 142 is sandwiched between the conical surface of the machining head 141 and the pressing surface (upstream side surface) of the pressing member 143 so as to be planetary rotatable, and the reduced diameter tube 202 faces the inner side of the tube. And press. As a result, the rolling tool 142 rotates in a planetary manner and presses the reduced diameter tube 202 against the grooved plug 113, thereby reducing the number of fins 205 (spiral grooves) along the spiral groove of the grooved plug 113. It can be formed on the inner surface of the tube 202. The fins 205 can be formed with a predetermined twist angle (lead angle), a predetermined fin height, and a predetermined fin interval with respect to the tube axis. The rolling tool 142 can be composed of a plurality of rollers, or can be composed of rollers and balls.

By this groove processing device 140, the reduced diameter tube 202 supplied from the upstream side becomes a groove applying tube 203 having grooves (fins 205) formed on the inner surface.
During the grooving, a grooving load R2 is applied to the reduced diameter tube 202 as shown in FIG.

The finishing device 150 includes a shaping die 151. The shaping die 151 is provided with a die hole 152 having a conical surface that widens toward the upstream side. The radius of the minimum radius portion of the die hole 152 is formed slightly smaller than the outer peripheral radius of the groove providing tube 203. By passing the groove-applying tube 203 through the die hole 152, the outer peripheral surface of the groove-applying tube 203 is slightly reduced in diameter and the shape is adjusted, and the finished inner surface grooved tube 204 can be obtained.
During this finishing process, a finish drawing load R1 is applied to the groove imparting pipe 203 as shown in FIG.

The winding drum 160 is a drum that winds the inner grooved tube 204. This winding is executed by the rotational force of the motor M1 according to the speed instruction signal of the controller 173. Further, the winding force becomes a straight drawing force F1 in a certain direction with respect to the raw tube 201, and a drawing torque can be generated to perform diameter reduction processing or inner surface groove processing.

That is, it is possible to reduce the diameter with the diameter reducing device 120 while drawing the raw tube 201 with the winding drum 160, perform groove processing with the groove processing device 140, and finish the outer peripheral surface with the finishing device 150.

Next, the apparatus used for sensing will be described. The diameter reducing device 120 and the auxiliary feeding device 130 are fixed to the upstream machine casing 102. The upstream machine casing 102 configured as described above is fixed to the upstream movable table 182 and can be reciprocally slid along the upstream movable table 182 in parallel with the drawing direction (horizontal in this embodiment). . That is, the upstream movable table 182 is provided with wheels 182a, and the wheels 182a are engaged with the rails 184b of the entire movable table 184, and can thereby move smoothly along the rails 184b. Accordingly, the diameter reducing device 120 and the auxiliary feeding device 130 move integrally with the upstream movable table 182.

Further, an upstream load detector 192 is provided at the end of the upstream movable table 182 in the drawing direction. The upstream load detector 192 is constituted by an appropriate detector capable of detecting a load such as a load cell. The upstream load detector 192 can detect the load of the upstream movable table 182 applied in the drawing direction during drawing as an upstream load detection value V (T1) (see FIG. 5).

The groove processing device 140 and the finishing device 150 are fixed to the entire machine casing 104. Further, the entire machine casing 104 configured as described above is fixed to the entire movable base 184, and reciprocally slides on the fixed base 186 along with the whole movable base 184 in parallel with the drawing direction (horizontal in this embodiment). it can. That is, the entire movable base 184 is provided with a wheel 184a, and the wheel 184a is engaged with the rail 186b of the fixed base 186, thereby being able to move smoothly along the rail 186b. Accordingly, the groove processing device 140 and the finishing device 150 are moved integrally with the entire movable table 184.

Also, an overall load detector 194 is provided at the end of the overall movable stand 184 in the drawing direction. The total load detector 194 is formed of an appropriate detector that can detect a load such as a load cell. With this total load detector 194, the load on the entire movable base 184 applied in the drawing direction during the drawing process can be detected as the downstream load detection value V (T2) (see FIG. 5).

Next, the apparatus used for control will be described. A controller 171, a speed setter 172, a controller 173, an upstream signal converter 174, an overall signal converter 175, and a calculator 176 are provided.

The controller 171 receives the rotation instruction speed S (H) from the calculator 176, and rotates the motor M2 at this speed. Further, the actual rotational speed and torque of the motor M2 are fed back to the calculator 176.
The speed setting unit 172 is a device that sets the drawing speed by the winding drum 160, and transmits a set value to the controller 173 and the calculator 176.

Controller 173 sets and instructs the rotational speed of motor M1 based on the drawing speed received from speed setter 172.
The upstream signal converter 174 converts a signal of a pressing force (detected by the upstream load detector 192) caused by the upstream movable base 182 carrying the upstream machine casing 102 in the drawing direction (material traveling direction) into an electrical signal, This signal is transmitted to the computing unit 176 as the upstream load detection value V (T1).

The overall signal converter 175 converts a signal of pressing force (detected by the overall load detector 194) caused by the overall movable base 184 carrying the overall machine casing 104 in the drawing direction (material traveling direction) into an electrical signal, This signal is transmitted to the computing unit 176 as the downstream load detection value V (T2).

The computing unit 176 performs computation based on the upstream load detection value V (T1) received from the upstream signal converter 174, the downstream load detection value V (T2) received from the overall signal converter 175, and various setting information. The rotation instruction speed S (H) of the motor M2 is adjusted as needed and transmitted to the controller 171.

Next, the operation of the internally grooved pipe manufacturing apparatus 101 will be described with reference to FIG. FIG. 6 is a flowchart showing the overall operation of the inner surface grooved pipe manufacturing apparatus 101.
First, the inner surface grooved pipe manufacturing apparatus 101 starts the winding drum 160 (step s1). Note that the controller 173 completes the manufacture of the internally grooved tube 204 based on the drawing speed received from the speed setting device 172 so as to be wound with a constant drawing force F1 according to the material and diameter of the raw tube 201. The speed of the motor M1 of the winding drum 160 is controlled.

Next, the inner surface grooved pipe manufacturing apparatus 101 starts the auxiliary feeding apparatus 130 (step s2). At this time, the controller 171 performs the first auxiliary feed speed control on the motor M2 so that the initial auxiliary feed speed (first auxiliary feed speed) corresponding to the material and diameter of the raw tube 201 is obtained (step s3). ). The initial auxiliary feed speed is a high speed in a range where the raw pipe 201 is not broken by the inner surface grooved pipe manufacturing apparatus 101 according to the material and diameter of the raw pipe 201 to be processed, and is set in advance. Is speed.

In the inner surface grooved pipe manufacturing apparatus 101 in this state, the raw pipe 201 is not broken, but the groove processing load R2 applied to the reduced diameter pipe 202 by the groove processing apparatus 140 is too large, and the fin 205 is not formed in the groove processing apparatus 140. Alternatively, the formed fin 205 cannot secure a predetermined accuracy.

In this state, the inner surface grooved pipe manufacturing apparatus 101 detects the upstream load detection value V (T1) with the upstream load detector 192 (step s4), and the downstream load detection value V (T2) with the overall load detector 194. ) Is detected (step s5) and transmitted to the computing unit 176.

The computing unit 176 calculates a load difference value (T3) that is a difference between the upstream load detection value V (T1) and the downstream load detection value V (T2) received from the upstream load detector 192 and the overall load detector 194 ( Step s6).

This load difference value (T3) indicates the total load of the grooving load R2 applied to the grooving device 140 and the finish drawing load R1 applied to the finishing device 150. More specifically, as described above, the upstream load detection value V (T1) is determined by the load of the upstream movable table 182 in the drawing direction during the drawing process, that is, the reduced diameter drawing load R3 in the diameter reducing device 120 and the auxiliary feed device 130. The total load of the auxiliary feed force F2 is shown.

On the other hand, the downstream load detection value V (T2) is the load of the entire movable base 184 in the drawing direction during the drawing process, that is, the reduced diameter drawing load R3 in the diameter reducing device 120, and the auxiliary feed force F2 by the diameter reducing device 120. The total load of the grooving load R2 in the grooving device 140 and the finish drawing load R1 in the finishing device 150 is shown.

Therefore, the load difference value (T3), which is the difference between the upstream load detection value V (T1) and the downstream load detection value V (T2), is the grooving load R2 applied to the grooving device 140 and the finish drawing applied to the finishing device 150. The total load of the load R1.

Here, in the finishing device 150, the outer peripheral surface of the groove-applying tube 203 is slightly reduced in diameter in order to obtain the inner-surface grooved tube 20 as a finished product. At this time, the finish drawing load R1 in the finishing device 150 is substantially constant and is negligibly small as compared with the reduced diameter drawing load R3 in the groove processing device 140. Therefore, the load difference value (T3) may be considered to be the reduced diameter drawing load R3 in the grooving apparatus 140 substantially.

Note that the reduced diameter drawing load R3 in the groove processing device 140 has a great influence on the formation of the fin 205 when forming the groove imparting pipe 203 from the reduced diameter pipe 202 supplied from the upstream side. Specifically, when the reduced diameter drawing load R3 in the groove processing apparatus 140 is smaller than a predetermined range set in advance, that is, the load in forming the fin 205 in the groove processing apparatus 140 is small, sufficient fins 205 can be formed. It means not.

Conversely, when the reduced diameter drawing load R3 in the groove processing apparatus 140 is larger than a predetermined range, that is, when the load in forming the fin 205 in the groove processing apparatus 140 is too large, the desired fin 205 cannot be formed in the same manner. .

Therefore, the arithmetic unit 176 causes the auxiliary feed device 130 to act on the reduced diameter pipe 202 so that the load difference value (T3) is within a predetermined range set in advance according to the material and diameter of the raw pipe 201. Torque is calculated (step s7).

The auxiliary feed torque is calculated based on the no-load torque and the rod friction torque, and becomes a torque for feeding the reduced diameter tube 202 toward the groove processing device 140 by the auxiliary feed device 130. The motor M2 in the auxiliary feed device 130 is Torque control cannot be performed to match the auxiliary feed torque calculated in step s7.

Therefore, the arithmetic unit 176 instructs the controller 171 to increase or decrease the speed so that the second auxiliary feed speed is determined based on the correlation with the auxiliary feed torque set in advance according to the material and diameter of the raw tube 201. The controller 171 executes torque control based on the received acceleration / deceleration instruction to the motor M2 (step s8).

In step s3, depending on the material and diameter of the raw pipe 201, the speed is increased to the initial auxiliary feed speed (first auxiliary feed speed), which is a high speed within a range in which the raw pipe 201 is not broken by the inner surface grooved pipe manufacturing apparatus 101. In this embodiment to be controlled, the second auxiliary feed speed determined based on the auxiliary feed torque for controlling the torque to the auxiliary feed device 130 in step s8, that is, the correlation with the auxiliary feed torque, is the initial auxiliary feed speed (first auxiliary feed speed). The speed is lower, and the controller 171 controls the motor M2 to decelerate.

The inner surface grooved pipe manufacturing apparatus 101 that has executed the torque control for the auxiliary feeder 130 in step s8 uses the upstream load detector 192 and the overall load detector 194 to detect the upstream load detection value V (T1) as in steps s4 to s6. And the downstream load detection value V (T2), and the calculator 176 calculates the load difference value (T3) after torque control of the auxiliary feeder 130, and the calculated load difference value (T3) is calculated in advance. It is determined whether it is within the set predetermined range (step s9).

When the load difference value (T3) after torque control of the auxiliary feeder 130 is not within the predetermined range (step s9: No), the process returns to step s4, and the calculator 176 has the load difference value (T3) within the predetermined range. The auxiliary feed torque is calculated so that

On the other hand, when the load difference value (T3) after torque control of the auxiliary feeder 130 is within a predetermined range set in advance (step s9: Yes), the controller 171 has a predetermined amount of the internally grooved tube 204. Is manufactured (step s10). If a predetermined amount of the internally grooved tube 204 has already been manufactured, the manufacture of the internally grooved tube 204 by the internally grooved tube manufacturing apparatus 101 is stopped (step s10: Yes). On the other hand, when the predetermined amount of the internally grooved tube 204 has not been manufactured yet (step s10: No), the process returns to step s4 until the predetermined amount of the internally grooved tube 204 can be manufactured. Repeat until.

Thus, by using the inner surface grooved pipe manufacturing apparatus 101 having the above-described configuration and executing the above-described control, it is possible to improve the productivity of the inner surface grooved pipe 204 in which the highly accurate fins 205 are formed. .
Specifically, the inner surface grooved pipe manufacturing apparatus 101 uses the calculator 176 to detect the upstream load detection value V (T1) detected by the upstream load detector 192 and the downstream load detection value V (T2) detected by the overall load detector 194. So that the load difference value (T3) substantially indicating the reduced diameter drawing load R3 in the groove processing device 140 is within a predetermined range set in advance according to the material and diameter of the raw tube 201. The auxiliary feed torque applied to the reduced diameter tube 202 is controlled by the feed device 130. For this reason, it is possible to stabilize the reduced diameter drawing load R3 that greatly affects the formation of the fins 205, and to form the fins 205 with desired accuracy even under the processing conditions close to the processing limit.

Therefore, for example, an internally grooved tube 204 with a precision that was impossible in the past (for example, a fin having a high twist angle (lead angle) of 40 to 60 ° with respect to the tube axis and having a fin height of 0.2 mm or more) A plurality of pipes formed on the inner surface such that the ratio H / t between the height H and the groove bottom wall thickness t between adjacent fins is 1.2 or less can be manufactured with high productivity.

Further, the auxiliary feed torque for controlling the torque of the auxiliary feed device 130 is determined by using the second auxiliary feed speed determined based on the correlation with the auxiliary feed torque set in advance according to the material and diameter of the raw tube 201. Therefore, it is possible to surely control the torque of the motor M2, which cannot be torque controlled, and to form the fins 205 with desired accuracy.

Furthermore, the inner grooved pipe manufacturing apparatus 101 has a high speed in a range in which the inner pipe 201 is not broken in the inner grooved pipe manufacturing apparatus 101 according to the material and diameter of the raw pipe 201 to be processed. Control is performed at the set first auxiliary feed speed. Thereafter, the auxiliary feed device 130 is torque-controlled at a second auxiliary feed speed that is lower than the initial auxiliary feed speed (first auxiliary feed speed) and determined based on the correlation with the auxiliary feed torque. For this reason, the productivity of the internally grooved tube 204 having the fins 205 formed with a desired accuracy can be improved.

Further, the inner grooved tube manufacturing apparatus 101 manufactures the inner grooved tube 204 having the fins 205 with a desired accuracy by controlling the torque of the auxiliary feeding device 130 while keeping the drawing force F1 by the winding drum 160 constant. The inner grooved tube 204 can be manufactured with high productivity without complicating the control.

In addition, a predetermined range and a second auxiliary feed speed that serve as a reference for controlling the drawing force F1, the initial auxiliary feed speed (first auxiliary feed speed), and the load difference value (T3) in the winding drum 160 are determined according to the material of the raw tube 201. Since it is set based on the speed, range and correlation according to the diameter, it can be processed corresponding to the load fluctuation due to the material and diameter of the raw tube 201. Therefore, it is possible to form the fin 205 with high accuracy regardless of the material and diameter of the raw tube 201 and to reduce the occurrence of breakage.

The inner grooved tube manufacturing apparatus 101 fixes the diameter reducing device 120 and the auxiliary feeding device 130 to the upstream movable table 182 that can move relative to the winding drum 160, and the raw tube 201 by the winding drum 160. An upstream load detector 192 is provided for detecting the load of the upstream movable table 182 that moves relative to each other when it is pulled out.

Thereby, for example, the diameter reducing device 120, the auxiliary feeding device 130, the groove processing device 140, and the finishing device 150 are fixed to the entire movable table 184 that can move relative to the winding drum 160, and the entire movable table 184 is fixed to the entire movable table 184. Compared with the internally grooved pipe manufacturing apparatus that detects such a load, the auxiliary feed torque by the auxiliary feed apparatus 130 that has a large influence on the formation of the fin 205 can be estimated from the detection result by the upstream load detector 192, and the torque can be controlled.

Therefore, the inner grooved tube 204 having the fins 205 with higher accuracy can be manufactured with high productivity.

The inner surface grooved pipe manufacturing apparatus 101 includes an upstream load detector 192 that detects a load applied to the upstream movable table 182 and an overall load detector 194 that is applied to the entire movable table 184. In addition to the load difference value (T3) calculated from the upstream load detection value V (T1) and the downstream load detection value V (T2) detected by the upstream load detector 192 and the overall load detector 194, the upstream load detection value V ( The auxiliary feeder 130 may be torque controlled in consideration of T1).

Further, the pulling force F1 by the winding drum 160 may be controlled in consideration of the downstream load detection value V (T2) detected by the overall load detector 194 in addition to the load difference value (T3). .

Thus, since the inner surface grooved pipe manufacturing apparatus 101 includes the upstream load detector 192 for detecting the load applied to the upstream movable table 182 and the overall load detector 194 applied to the entire movable table 184, further thinning is achieved. Even if the twist angle (lead angle) of the fin 205 is further increased, the complexity of the control is increased, but the productivity of the internally grooved tube 204 in which the fin 205 with higher accuracy is formed is improved. can do.

Further, since the upstream load detector 192 and the entire load detector 194 are configured by the same device, the change curves of the values detected from both detectors are approximated, and the speed of the auxiliary feeding device 130 and the winding drum 160 are Torque can be adjusted with high accuracy.

Note that, in the correspondence between the above-described Embodiment 2 and the configuration of the present invention, the diameter reducing device 120 of this embodiment corresponds to a diameter reducing means.
The auxiliary feeding device 130 corresponds to the feeding assisting means,
The groove processing device 140 corresponds to the groove processing means,
The winding drum 160 corresponds to the drawing means,
The controller 171 and the calculator 176 correspond to control means,
The auxiliary feed speed corresponds to the feed auxiliary speed,
The auxiliary feed torque corresponds to the feed auxiliary torque,
The upstream movable table 182 corresponds to the moving table,
The entire movable base 184 corresponds to the base,
The upstream load detector 192 corresponds to the moving table load detector,
The total load detector 194 corresponds to the base load detection device,
Step s3 corresponds to the feed assist speed adjustment process,
Step s8 corresponds to the feed assist torque adjustment process,
Although the pressing tool corresponds to the processed ball 326, the present invention is not limited only to the configuration of the second embodiment, and many embodiments can be obtained.

(Embodiment 3)
Next, a manufacturing apparatus 312 and a manufacturing method for an internally grooved tube according to Embodiment 3 will be described with reference to the drawings.
In addition, FIG. 7 is explanatory drawing of the manufacturing apparatus 312 of an inner surface grooved pipe | tube in this embodiment.

As shown in FIG. 7, the inner surface grooved tube manufacturing apparatus 312 according to the present embodiment has a diameter reducing means 313 for reducing the diameter of the element tube 311a along the drawing direction X of the element tube 311a, and an inner surface of the element tube 311a. A groove processing means 314 for forming a large number of grooves is provided, and an intermediate extraction portion 317 is provided between the diameter reducing means 313 and the groove processing means 314 for extracting the raw tube 311a reduced in diameter by the diameter reducing means 313. ing.

The diameter-reducing means 313 includes a diameter-reducing die 322 and a floating plug 323 that is disposed in the element tube 311a and reduces the diameter of the element tube 311a together with the diameter-reducing die 322.

The groove processing means 314 is rotatably connected to the floating plug 323 via a connecting rod 325 in the raw tube 311a, and has a grooved plug 324 having a plurality of grooves formed on the outer periphery, and an outer side of the raw tube 311a. In FIG. 2, the raw tube 311a is composed of a plurality of processed balls 326 arranged to revolve around the tube axis while being pressed toward the grooved plug 324 side.

In the manufacturing apparatus 312 and the manufacturing method of the internally grooved tube 311 using the manufacturing apparatus 312, as shown in FIG. 8, the outer diameter D _o (mm) of the raw pipe 311 a and the diameter D of the reduced diameter die 322. ₂ (mm), the diameter reduction ratio R _D of the element tube 311a represented by R _D = {(D _o −D ₂ ) / D _o } × 100 (%) is reduced to 30% or less in the diameter reducing means 313. It is set.

Further, the outer diameter D ₁ (mm) of the floating plug 323 and the diameter D ₂ (mm) of the reduced diameter die 322 are set to satisfy D ₁ −D ₂ ≧ 0.1.

Furthermore, the revolution direction of the processed ball 326 is set in the reverse direction, and the processed pitch P (mm) of the processed ball 326 is set in a range of 0.2 ≦ P ≦ 0.7.

Alternatively, when the revolution direction of the processed ball 326 is set to the positive direction, the processing pitch P (mm) is set to be in the range of 0.2 ≦ P ≦ 0.4.

Hereinafter, the manufacturing apparatus 312 of the inner surface grooved pipe in the present embodiment will be described in detail.
The manufacturing apparatus 312 includes a diameter reducing means 313, an intermediate drawing portion 317, a groove processing means 314, a shaping die 315, and a drawing portion 316 along the drawing direction X from the upstream side to the downstream side.

Further, the manufacturing apparatus 312 supports a movable base 333 that supports the reduced diameter portion 313, the intermediate extraction portion 317, and the groove processing means 314 so as to be movable in the drawing direction with respect to the fixed base 350, and the fixing of the movable base 333. A load cell 328 that detects a load F that acts in response to movement relative to the table 350, and a control device 345 that controls the intermediate pull-out portion 317 and the pull-out portion 316 based on the load F detected by the load cell 328. Yes.

The diameter reducing means 313 includes the diameter reducing die 322 and the floating plug 323 as described above.
The diameter-reducing die 322 is formed in a cylindrical shape having a communication hole 322a communicating with the drawing direction X, and the communication hole 322a has an upstream portion (inlet side) in the drawing direction X as a downstream portion (outlet side). On the other hand, it is configured in a shape that opens toward the upstream side.

The floating plug 323 is formed in a cylindrical shape, and the outer periphery of the downstream portion is formed in a tapered shape.

As shown in FIG. 8, the outer diameter of the floating plug 323 is set to D ₁ (mm), and the inner diameter on the outlet side of the reduced diameter die 322 is set to D ₂ (mm).

The groove processing means 314 includes a grooved plug 324, a plurality of processing balls 326, and a processing head 327 that holds the processing balls 326 from the outer peripheral side.

The processing head 327 is formed with a processing ball holding groove 327a having a semicircular cross section.
The plurality of processed balls 326 are held so as to revolve freely while pressing the surface of the raw tube 311a by the processed ball holding grooves 327a. The plurality of processed balls 326 are held by the processed ball holding grooves 327a so that the revolution speed can be changed while pressing the surface of the raw tube 311a in either the forward direction or the reverse direction.

The shaping die 315 performs a process of smoothly shaping, for example, the distortion of the pipe surface caused by the pressing of the machining ball 326 in the grooving means 314 when the inner grooved pipe 311 passes.

The drawing portion 316 also has a winding drum 336 that winds up the processed inner surface grooved tube 311, and includes a motor M ₁ that drives the winding drum 336, and the inner surface grooved tube 311 is driven by rotation of the motor M _1. Is wound around the winding drum 336.

The intermediate drawing portion 317 assists the drawing by the drawing device 316 by drawing the raw tube 311a in the drawing direction X between the reduced diameter portion 313 and the groove processing means 314. That is, the grooving by the grooving means 314 becomes a resistance when pulling out the raw tube 311a, and the pulling load during the grooving increases, but the pulling load applied to the raw tube 311a by the intermediate pulling portion 317 is increased. Can be dispersed.

The intermediate extraction portion 317 includes a pair of

belts

342a and 342a arranged on the upper and lower sides or the left and right sides with respect to the raw tube 311a. Each

belt

342a, 342a are formed in a loop shape (endless) and is tensioned by a rotatable pulley 343 by the rotation of the motor _{M 2.} The

belts

342a and 342a have a plurality of pads 344 arranged on the outer peripheral surface along the length direction.

Although not shown in the drawing, the pad 344 is formed with a pad groove in which a cut surface with respect to the connecting direction of the plurality of pads 344 has an arc shape at a contact portion with the outer surface of the base tube 311a after the diameter reduction by the diameter reducing portion 313. is doing.

The intermediate withdrawal part 317 has a pad 344 configured to be pressed against the base pipe 311a surface by driving of the motor _{M 3.}
A wiper 351 is provided on the upstream side of the intermediate extraction portion 317 to remove an oil film and foreign matter adhering to the outer surface of the raw tube 311a, and an intermediate shaping die 352 is provided on the downstream side.

The wiper 351 is provided to remove an oil film and foreign matter adhering to the outer surface of the raw tube 311a, and a through hole having a diameter slightly smaller than the outer diameter of the raw tube 311a is provided to pass the raw tube 311a. For example, a rubber cylindrical body formed in the central portion.
In addition, when the wiper 351 is not installed, slipping occurs in the intermediate extraction portion 317 due to an oil film or a foreign substance, and the drawing of the raw tube 331c is not stable, and the cross-sectional shape is not stable, so that the size of the groove varies. Will occur.

The intermediate shaping die 352 is provided to return the cross-sectional shape of the element tube 311a flattened by the intermediate extraction portion 317 to a shape close to a perfect circle, and has the same diameter as the floating die 322 depending on the shape of the element tube 311a. It is configured with a small die diameter.
The intermediate shaping die 352 is made of a material harder than the material of the metal element tube 311a such as metal or ceramic. Preferably, it is made of cemented carbide.

The movable table 333 is installed on the fixed table 350 via a plurality of wheels 333a so that the movable table 333 can be translated in the drawing direction or the opposite direction with respect to the fixed table 350. Means 314, finishing section 315, intermediate drawing section 317, wiper 351 and intermediate shaping die 352 are installed in a state where they are housed in box 332.

The load cell 328 is provided on the fixed base 350 at the downstream end portion in the drawing direction of the movable table 333 so that the load F received from the movable table 333 according to the pulling force of the raw tube 311a can be detected.

The control unit 345 receives a load detection signal S _{in obtained} by converting the load F detected by the load cell 328 into an electrical signal, and the motors M ₁ , M ₂ , M _{3 of the} extraction unit 316 and the intermediate extraction unit 317 according to a control program. A control signal S _out for controlling the driving of the signal is output.

Further, although not shown, the control unit 345 temporarily stores an arithmetic unit (CPU) for executing signal analysis processing and arithmetic processing, a hard disk for storing necessary control programs, and the load detection signal S _in. In addition, an input unit such as a keyboard for inputting control parameters and a display unit such as a monitor can be appropriately provided.

The control unit 345, by controlling the driving of the motor _{M 3} of the intermediate withdrawal unit 317, and controls the pressing force by the pad 344 of the intermediate pullout portion 317 against base pipe 311a.
By pressing the pad 344 against the raw tube 311a with an appropriate pressing force, the slip between the pad 344 and the raw tube 311a is reduced, and the variation in the load F is reduced.

When the fluctuation of the load F becomes large, the shape of the groove in the longitudinal direction varies, and if the depth of the groove in the longitudinal direction varies, a certain heat transfer performance cannot be secured, and the aluminum fin of the heat exchanger This is because there is a variation in the degree of tube expansion when the tube is installed, and therefore the tube expansion is partially insufficient, resulting in a decrease in heat exchanger performance due to insufficient adhesion with the aluminum fins.

In order to reduce the fluctuation of the load F, the rotation of the

belts

342a and 342a at the intermediate extraction portion 317 may be controlled. In this case, the control unit 345 may be configured to control other control parameters such as the rotation speed and acceleration, not limited to the rotation torque of the pulley 343.

Then, the manufacturing method of the inner surface grooved tube 311 using the inner surface grooved tube manufacturing apparatus 312 described above includes a diameter reduction process step of reducing the diameter of the raw tube 311a in the process of moving the raw tube 311a in the drawing direction X. An intermediate drawing is performed in which a groove machining step for forming a large number of grooves on the inner surface of the element tube 311a is performed, and the element tube 311a reduced in diameter in the diameter reduction process step is drawn during the diameter reduction process and the groove machining process. Perform the process.

The diameter reducing process is performed by a diameter reducing die 322 and a floating plug 323 which is disposed in the element pipe 311a and reduces the diameter of the element pipe 311a together with the diameter reducing die 322.
In the groove processing step, a grooved plug 324 that is rotatably connected to the floating plug 323 through a connecting rod 325 in the raw tube 311a and has a plurality of grooves formed on the outer periphery, and on the outer side of the raw tube 311a. This is performed with a plurality of processed balls 326 arranged to revolve around the tube axis while pressing the raw tube 311a toward the grooved plug 324 side.

The manufacturing apparatus 312 and the manufacturing method can achieve the following operational effects.
As described above, the manufacturing apparatus 312 and the manufacturing method are configured such that R _D = {(D _o −) by the outer diameter D _o (mm) of the raw tube 311a and the diameter D ₂ (mm) of the reduced diameter die 322. The diameter reduction ratio R _D of the element tube 311a expressed by D ₂ ) / D _o } × 100 (%) is set to 30% or less in the diameter reduction means 313.

For this reason, the so-called chatter phenomenon in which the tube 311a slightly vibrates after the diameter reduction by the diameter reducing means 313 is suppressed, and the load assist for assisting the extraction load by the intermediate extraction portion 317 can be stabilized.

As described above, in the manufacturing apparatus 312 and the manufacturing method, the outer diameter D ₁ (mm) of the floating plug 323 and the diameter D ₂ (mm) of the reduced diameter die 322 are set such that D ₁ −D ₂ ≧ 0. It is set to be 1.

For this reason, it is possible to more effectively suppress the occurrence of chattering phenomenon, and it is possible to reduce the thickness by thinning during the diameter reduction process.

As described above, in the manufacturing apparatus 312 and the manufacturing method, when the revolution direction of the processing ball 326 is set in the reverse direction, the processing pitch P (mm) is in the range of 0.2 ≦ P ≦ 0.7. It is set to become.

Therefore, it is possible to stably manufacture a grooved tube with high groove processing accuracy.

Alternatively, as described above, in the manufacturing apparatus 312 and the manufacturing method, when the revolution direction of the processed ball 326 is set to the positive direction, the processing pitch P (mm) of the processed ball 326 is set to 0.2 ≦ P ≦. It is set to be in the range of 0.4.

This makes it possible to obtain a deep groove and a high machining accuracy without causing any escaping at the bottom of the inner fin.

(Example)
Subsequently, in order to verify the effectiveness of the manufacturing apparatus 312 of the third embodiment and the manufacturing method, a processing experiment was performed in which the raw tube 311a was processed into the internally grooved tube 311 (Examples 10 to 15).
In the tenth embodiment, the diameter reduction ratio R _D of the raw tube 311a in the diameter reducing means 313, in the eleventh embodiment, the floating plug 323 and the reduced diameter die 322 are engaged (D ₁ -D ₂ ). The processing pitch P of the ball 326, the groove depth and the twist angle of the grooved plug 324 in Example 13, the revolution speed of the processing ball 326 in Example 14, and the number of the processing balls 326 in Example 15 are parameters. And the quality of processing was evaluated.

Hereinafter, each of Examples 10 to 15 will be described in detail.

(Example 10)
In Example 10, it was subjected to grooving experiment to investigate the effect on the processing by changing the radial contraction rate R _D of the base pipe 311a at reduced diameter section 313.

In this machining experiment, machining pipes 311a were machined by setting machining conditions for each of Invention Examples 1 to 3 and Comparative Examples 1 and 2, and an internally grooved tube 311 was created.

In Invention Examples 1 to 3 and Comparative Examples 1 and 2, the thickness (T _o ) of the raw tube 311a, the diameter (D ₂ ) of the reduced diameter die 322, the outer diameter (D ₁ ) of the floating plug 323, and the grooved plug The outer diameter, the number of grooves, the twist angle, the groove depth, the groove apex angle, the number of processed balls 326, the revolution speed, and the processing pitch of 324 were processed under common conditions as shown in Table 4.

The further processing experiments, the present invention Examples 1-3, as shown in Table 5 for each of Comparative Examples 1 and 2, a die diameter _{D 2} of the diameter reduction dies 322 is constant, only the outer diameter _{D o} of the base pipe 311a The diameter reduction ratio _RD was changed by changing.

As shown in Table 5, in each of Invention Examples 1 to 3, the diameter reduction ratio _RD was set to be 30% or less, and in Comparative Examples 1 and 2, the diameter reduction ratio _RD was larger than 30%. Processing was performed under the following settings.

The processing result was evaluated by the variation in the groove depth in the longitudinal direction of the groove formed on the inner surface of the raw tube 311a after the grooving.
Further, the variation in the depth of the groove in the longitudinal direction and the degree of stability of the load F detected at the time of diameter reduction by the load cell 328 installed in the diameter reduction means 313 are closely related. For this reason, when a load fluctuation occurs, it affects the groove shape (particularly the groove depth) formed on the inner surface of the raw tube 311a, and the magnitude of the load fluctuation is the same as the fluctuation of the groove depth in the longitudinal direction of the groove. Appears in size.

Therefore, by evaluating the variation in the groove depth in the longitudinal direction of the groove formed on the inner surface of the raw tube 311a, it is possible to evaluate the degree of stability of the load F detected during the diameter reduction processing.

The processing result is “◎” when the variation in the groove depth in the longitudinal direction indicating the stability of the load is 0 to 0.020 mm, and “◯” when the variation is 0.021 to 0.050 mm. The case of 0.051 mm or more was evaluated as “x”.

Table 5 shows the results of machining performed under the conditions of Invention Examples 1 to 3 and Comparative Examples 1 and 2.

As shown in Table 5, Example 1 of the present invention was “◯”, Examples 2 and 3 of the present invention were “◎”, and Examples 1 to 3 of the present invention obtained the desired internally grooved tube 311, In Comparative Examples 1 and 2, both were “x”, and the desired internally grooved tube 311 was not obtained.

Specifically, when the diameter reduction ratio _RD is greater than 30%, as in Comparative Examples 1 and 2, the variation in groove depth in the longitudinal direction of the groove increases.

When radial contraction rate _{R D} of the base pipe 311a is greater than 30%, as shown in FIG. 12 (a), the frictional resistance increases the contact area A of the the mother tube 311a diameter die 322A is increased. Then, the processing load at diameter reduction dies 322A is increased, pulling the outer diameter _{D f} of the base pipe 311a is narrower than the diameter _{D 2} of the outlet of the reduced diameter die 322A thinning occurs (FIG. 12 ( (See an enlarged view of the area Z1 in a)).

Further, the contact between the raw tube 311a and the reduced diameter die 322A is not stabilized by the thinning, the chatter phenomenon is likely to occur, and the thickness is reduced.

Thus, reduced diameter section 313 the outer diameter D _f of the base pipe 311a after passing becomes smaller than the diameter D ₂ of the diameter reduction dies 322A "pull thinning" or degree of "thickness reduction" is increased, the intermediate pullout The load assist at the portion 317 became unstable. In addition, chatter phenomenon in which the pipe vibrates slightly occurred, and the instantaneous fluctuation of the load increased accordingly.
For this reason, it is thought that it appeared in the result of the variation in the groove depth in the longitudinal direction of the groove increased in Comparative Examples 1 and 2.

In the inner grooved tube 311 having the groove depth varying in the longitudinal direction as in Comparative Examples 1 and 2, the heat transfer performance decreases. In addition, since the degree of expansion of pipes varies when the heat exchanger is expanded and incorporated into the aluminum fins, the expansion of the pipes is partially insufficient and the heat exchanger performance is deteriorated due to insufficient adhesion with the aluminum fins.

∙ If the load fluctuation is large, it may break during processing, so it is desirable that the load fluctuation is small.

In contrast, as the results in Table 5, if radial contraction rate R _D is 30% or less in diameter means 313, variation of the groove depth in the longitudinal direction as in the present invention Examples 1-3 It has become smaller. Thereby, it was proved that the stability of the load F was good, and in particular, the stability of the load F was improved as the diameter reduction ratio _RD was small.

Specifically, in Examples 1 to 3 of the present invention, as shown in FIG. 9, when the diameter reduction ratio _RD is 30% or less and D ₁ −D ₂ ≧ 0.1, the raw tube 311a after the diameter reduction processing is performed. since the outer diameter _{D f,} becomes substantially the same as the diameter _{D 2} of the diameter reduction dies 322, the thickness _{T f} of the base pipe 311a after diameter reduction is increased equal to or slightly thicker _{T o} of the base pipe 311a Processing was realized.

Example 11
In Example 11, a grooving experiment was conducted to examine the influence on the machining by changing the engagement (D ₁ -D ₂ ) of the floating plug 323 and the reduced diameter die 322 in the diameter reducing means 313.
In this processing experiment, the raw tube 311a was processed for each of the conditions of Invention Examples 4 to 8 and Comparative Example 3 to create an internally grooved tube 311.

In this machining experiment, the outer diameter D _{1 of the} floating plug 323 with respect to the die diameter D ₂ of the constant diameter-reduced die 322 as shown in Table 6 under the machining conditions of Invention Examples 4 to 8 and Comparative Example 3. And the degree of meshing (D ₁ -D ₂ ) between the floating plug 323 and the reduced diameter die 322 was changed.

In Examples 4 to 8 of the present invention, (D ₁ -D ₂ ) is all set to 0.1 or more, and in Comparative Example 3, (D ₁ -D ₂ ) is set to be smaller than 0.1. Was processed.

Table 6 shows the results of machining performed under the machining conditions of Invention Examples 4 to 8 and Comparative Example 3.
The present invention Examples 4-8, Comparative Example 3, 9.53 mm outer diameter _{D o} of the blank tube 311a, using the base tube 311a of the common dimensions of 8.93mm internal diameter, for the other conditions, As shown in Table 4, processing was performed under common conditions. In addition, the processing results were evaluated as “評価”, “◯”, and “×” based on the variation in groove depth in the longitudinal direction of the grooves formed after grooving, as in Example 10. .

As is apparent from Table 6, in Examples 4 to 8 of the present invention, the processing result was “◎” or “◯”, and the desired internally grooved tube 311 was obtained, whereas in Comparative Example 3, the processing result was obtained. Became “x”, and the desired internally grooved tube 311 could not be obtained.

Thus, when (D ₁ -D ₂ ) is smaller than 0.1, the load on the diameter reducing means 313A becomes unstable as in Comparative Example 3.

Specifically, when the engagement (D1-D2) of the floating plug 323A and the reduced diameter die 322A is smaller than 0.10 mm, as shown in the enlarged view of the region Z3 in FIG. 12B, the corner portion C of the floating plug 323A is shown. Only the vicinity contacts the inner surface of the raw tube 311a, and the load applied in the drawing direction X is received only in the vicinity of the corner C.

Normally, when the diameter is reduced, the thickness of the raw tube 311a is not reduced, and conversely, the thickness may be increased within 0.01 mm, whereas (D ₁ -D ₂ ) is 0.1. If it is smaller, the diameter of the tube 311a is reduced while reducing the thickness, and the load is excessively applied, and as shown in the enlarged view of the region Z2 in FIG. Thinning occurs.

As the meshing (D ₁ -D ₂ ) of the floating plug 323A and the reduced diameter die 322A decreases, the instantaneous fluctuation of the load increases. In particular, when (D ₁ -D ₂ ) is smaller than 0.10 mm, the tube becomes finer. The vibration chatter phenomenon also occurs, and the instantaneous fluctuation of the load further increases, and the degree of thinning also changes.
As a result, the base tube 311a may be broken by the diameter reducing means 313A.

When the intermediate extraction portion 317 is provided in this state, the contact area between the pad 344 and the raw tube 311a at the intermediate extraction portion 317 is fluctuated and a sufficient contact area cannot be secured, and load assistance at the intermediate extraction portion 317 is not possible. It becomes unstable. In addition, when the intermediate extraction portion 317 is provided, the number of contacts of the pads 344 is changed, or vibration due to repeated contact and release of the pads 344 with the base tube 311a is affected, so that conventional processing without the intermediate extraction portion 317 is performed. Compared with the method, the instantaneous fluctuation of the load becomes larger.

On the other hand, if (D ₁ -D ₂ ) is 0.1 or more, the load stability at the diameter reducing means 313 is good as in Examples 4 to 8 of the present invention. As shown in FIG. 9, it was proved that machining under a stable load can be performed as (D ₁ -D ₂ ) is larger from the machining results of ˜6.

(Example 12)
In Example 12, a grooving experiment was conducted to examine the effect on machining by changing the machining pitch P.
In this machining experiment, as in the conditions of Invention Examples 9 to 32 shown in Table 7, the inner surface is grooved under the machining conditions in which the machining pitch P is changed when the revolution direction of the machining ball 326 is the forward direction and the reverse direction. The tube 311 was processed.

Examples 9 to 32 of the present invention were obtained by processing the internally grooved tube 311 under the processing conditions satisfying the conditions of the present invention in which the reduction ratio _RD was 30% or less. Invention Examples 11 to 18 and Invention Examples 23 to 25 surrounded by a thick frame are obtained by processing the internally grooved tube 311 under particularly preferable processing conditions.

Specifically, in Examples 11 to 18 of the present invention, the revolution direction of the processed ball 326 is set to the reverse direction, and the processing is performed under the setting where the processing pitch P (mm) is 0.2 mm or more and 0.7 mm or less. In Invention Examples 23 to 25, the revolving direction of the processed ball 326 was set to the positive direction, and the processing was performed under a setting in which the processing pitch P (mm) was 0.2 mm or more and 0.4 mm or less.

On the other hand, in Examples 9, 10, 19, and 20 of the present invention, the revolution direction of the processed ball 326 is set to the reverse direction, and the processing pitch P (mm) is set to be smaller than 0.2 mm or larger than 0.7 mm. Was processed. In each of the inventive examples 21, 22, 26 to 32, the revolution direction of the processing ball 326 is set to the positive direction, and the processing pitch P (mm) is set to be smaller than 0.2 mm or larger than 0.4 mm. Was processed.

In Examples 9 to 32 of the present invention, the common tube 311a having an outer diameter of 9.53 mm and an inner diameter of 8.93 mm is used, and the other conditions are the same as shown in Table 4. Was processed.

Here, the processing pitch P (mm) means that the processing ball 326 revolves around the base tube 311a by an angle equally distributed on the outer periphery of the base tube 311a by the number of processing balls 326 arranged on the outer periphery. The distance the tube 311a travels in the drawing direction X is shown.
Specifically, in the twelfth embodiment, since four processed balls 326 are arranged on the outer periphery of the raw tube 311a, as shown in FIG. 10, the processed tube 326 rotates while the outer periphery of the raw tube 311a rotates 90 degrees. The moving distance P that 311a travels in the drawing direction X is set as the processing pitch P.

FIG. 10 is an explanatory diagram for explaining the processing pitch P schematically shown by partially omitting the vicinity of the groove processing means 314. In addition, La, Ld, and Lb indicated by phantom lines in FIG. 10 are the three processed

balls

326a, 326a,

Reference numerals

326d and 326b indicate trajectories of pressing the raw tube 311a. Furthermore, FIG. 10 shows a case where the revolution direction of the processed ball 326 is the reverse direction (the reverse direction to the rotation direction of the grooved plug 324). When the processed ball 326 is in the positive direction, the trajectories La, Lb, and Ld of the processed ball 326 are lowered to the right in FIG.

The processing results were evaluated by “groove formation” (whether or not the tube meat was unfilled) and “groove processing accuracy” (occurrence of aggression) formed on the inner surface of the raw tube 311a after grooving.

Here, as shown in FIG. 11, “egre” indicates an unfilled portion 401 of a material having a shape such that the fin 400 is notched in the thickness direction at the skirt of the inner surface fin 400 in the groove processing means 314. .

“Groove formation” is defined as “◯” when the entire groove of the grooved plug 324 is filled with meat (having a groove with a predetermined depth) and without filling (having a predetermined depth). (Where no groove was formed) was evaluated as “Δ” or “×”. “Δ” is unfilled, but is in a practically usable range. Furthermore, "the processing accuracy of Groove" gouge is missing or gouges depth H _e is what is within 10% of the fin Hem and "◎" gouges depth H _e is within 30% of the fin Hem Those with a value of “◯” were evaluated, and those with 30% or more were evaluated as “Δ” or “×”. "△" is gouge depth H _e is equal to or more than 30% of the fin Hem, practically, is within the range that can be used.

Table 7 shows the results of the processing performed for each condition of Invention Examples 9 to 32.

As is clear from Table 7, Examples 9 to 32 of the present invention were any of “◎”, “◯”, and “Δ”, and there was no “×”. In particular, in Examples 11 to 18 and 23 to 25 of the present invention, all were “◎” or “○”.

Specifically, as shown in Table 7, “groove formation” is “△” in Invention Examples 9, 10, 21 and 22, while “O” in Invention Examples 11 to 20, 23 to 32. " From this result, it was proved that the groove on the inner surface can be formed to a predetermined depth when the processing pitch P is 0.20 mm or more regardless of the revolution direction of the processing ball 326.

Further, “groove processing accuracy” was “△” in Invention Example 20, but “「 ”or“ ◯ ”in Invention Examples 9 to 19. From this result, it was proved that when the machining pitch P is 0.70 mm or less in the case where the revolution direction of the machining ball 326 is the reverse direction, it is particularly difficult to cause the escaping at the hem portion of the inner fin.

Furthermore, regarding the “groove processing accuracy”, in Examples 26 to 32 of the present invention, “Δ”, whereas in Examples 21 to 25 of the present invention, “◯” or “◎”. In the case where the revolution direction of the processed ball 326 is the positive direction, it has been proved that when the processing pitch P is 0.40 mm or less, it is particularly difficult for the hems of the inner fins to be prone to the occurrence of an egg.

Thus, if the depth of the angle is within 30% of the fin hem width, it is preferable that there is no possibility that the inner fin will fall when the heat exchanger is assembled into the aluminum fin in the post-processing.

As described above, the inventive examples 11 to 18 and the inventive examples 23 to 25 have the inner grooved tube 311 of the inner grooved tube 311 under particularly preferable processing conditions in the examples of the present invention from the viewpoints of “groove formation” and “groove processing accuracy”. We were able to demonstrate that processing was possible.

Specifically, when the revolution direction of the processed ball 326 is set to the reverse direction and the processing pitch P (mm) is set to be in the range of 0.2 ≦ P ≦ 0.7, or the revolution of the processed ball 326 is The effectiveness of the present invention characterized by setting the direction to the positive direction and setting the machining pitch P (mm) to be in the range of 0.2 ≦ P ≦ 0.4 could be verified.

(Example 13)
In Example 13, a grooving experiment was conducted to examine the effect of changing the groove depth and twist angle of the grooved plug 324 in the grooving process.
In this machining experiment, the machining pitch P of the machining balls 326 is changed to 0.20 mm, 0.40 mm, and 0.60 mm when the revolution direction of the machining balls 326 is the forward direction and the reverse direction, respectively. I did it.
Further, in the processing performed in this processing experiment, using a common dimension of base pipe 311a outer diameter _{D o} is φ9.53mm raw tube 311a, reduced diameter die diameter _{D 2,} the floating plug outside diameter _{D 1,} a grooved The outer diameter of the plug 324, the number of grooves, the groove apex angle, the number of processed balls 326, and the revolution speed were the same as in Example 10 under the common conditions shown in Table 4.

The processing results are as shown in Tables 8 to 10.
Tables 9 and 10 show the results of experiments performed by changing the groove depth and twist angle of the grooved plug 324 and the processing pitch P of the processing balls 326 when the revolving direction of the processing balls 326 is the forward direction and the reverse direction, respectively. Indicates.

Furthermore, Table 8 shows the experimental results obtained by extracting the processing conditions in Tables 9 and 10 and a part of the processing results.

As in Example 12, the machining results were verified with respect to “groove formation” and “groove machining accuracy”, and all of these elements were “O” or “◎”. Was evaluated as “x”, and “x” was not included in any of them, and “Δ” was included in one of them.

As shown in Tables 8 to 10, also in the processing experiments in Example 13, the inner grooved tube under the processing conditions satisfying the conditions of the present invention in which the diameter reduction ratio _RD is 30% or less. Since 311 was processed, there was no “×”.

Generally, in the case of a machining condition in which machining with a deep groove and a large helix angle is difficult, for example, in a machining condition where the groove depth is greater than 0.20 mm and the helix angle is greater than 55 degrees, Requires a large pulling force.

As shown in Table 8, even when the groove depth of the grooved plug 324 is deeper than 0.20 mm (0.22 mm) and the twist angle is larger than 55 degrees (60 degrees), the revolution direction of the processed ball 326 is If it was in the positive direction and the processing pitch was in the range of 0.20 mm to 0.40 mm, the processing result was “◯” and processing was possible (see the column * 1 in Table 8).

From this result, even when the groove of the grooved plug 324 is deep and machining with a large helix angle is difficult, the revolution direction of the machining ball 326 is the positive direction and the machining pitch P does not become too large. If it was 0.4 mm, it was proved that processing was possible.

On the other hand, as shown in Table 8, even when the groove depth of the grooved plug 324 is smaller than 0.20 mm such as 0.18 mm or 0.15 mm and the twist angle is smaller than 55 degrees such as 50 degrees, If the revolution direction of the processed ball 326 is the reverse direction, the processing results were all “◯” regardless of the setting of the processing pitch P, and the processing was possible (see the column * 2 in Table 8).

From this result, when the groove depth of the grooved plug 324 is small and the helix angle is small, at the same processing pitch P, the direction of revolution of the processed ball 326 is reverse as compared to the case of the positive direction. Since it is difficult to generate the egress on the inner surface of the fin and is small even if generated, it was proved that the processing pitch P can be set as large as 0.6 mm, for example.

In general, the larger the processing pitch P, the higher the processing speed and the productivity. Therefore, when the revolving direction of the processed ball 326 can be processed in the reverse direction, the revolving direction of the processed ball 326 is processed in the reverse direction. preferable.

(Example 14)
In Example 14, a grooving experiment was conducted to examine the effect of the revolution speed R (rpm) of the machining ball 326 on the machining.
Here, generally, the drawing speed at the time of machining the internally grooved tube 311 is V (m / min), the revolution speed of the machining ball 326 is R (rpm), the machining pitch of the machining ball 326 is P (mm), When the arrangement number of the balls 326 is C (pieces), the drawing speed V (m / min) can be expressed by V = R × P × C / 1000 (1). From this equation (1), it can be seen that even if the revolution speed is changed by R (rpm), the machining pitch P (mm) can be kept constant by changing the drawing speed by V (m / min) accordingly. .

Therefore, in this machining experiment, the drawing speed V was set based on the formula (1) so that the machining pitch of the machining ball 326 is constant for each revolution speed of the machining ball 326 of 10,000 rpm, 30000 rpm, and 40000 rpm. Processing experiments similar to Example 12 and Example 13 were performed.

As a result, even if the revolution speed of the processed ball 326 was changed, the same result as in Example 12 and Example 13 was obtained if the processing pitch P was the same.

After all, if the processing pitch P can be kept within a predetermined range, it can be demonstrated that the same evaluation result can be obtained regardless of the difference in the revolution speed of the processing ball 326. The revolution speed of the processing ball 326 may be appropriately selected in consideration of the life of a processing tool such as the processing ball 326.

(Example 15)
In Example 15, a grooving experiment was conducted to examine the influence of the number C (number) of processed balls 326 arranged.
Here, according to the relationship of the formula (1), even if the number C (number) of the processing balls 326 is changed, the drawing speed is changed by V (m / min) or the revolution speed R (rpm). The processing pitch P (mm) can be kept constant.

Therefore, in Example 15, in each of the cases where the number C of the processed balls 326 is 3 and 5, the drawing speed is set to V so as to keep the processing pitch P (mm) constant based on the relationship of the expression (1). (M / min) and revolution speed were set to R (rpm), respectively, and processing experiments similar to those of Example 12, Example 13, and Example 14 were performed.

As a result, even if the revolution speed of the processed ball 326 was changed, the same results as in Example 12, Example 13 and Example 14 were obtained as long as the processing pitch P was the same.

After all, if the processing pitch P can be kept within a predetermined range, it was proved that the same evaluation result can be obtained regardless of the difference in the number C (number) of processing balls 326. The number of processing balls 326 may be appropriately selected depending on the inner grooved tube 311 to be processed.

In addition, in the correspondence between the above-described Embodiment 3 and the configuration of the present invention, the processing ball 326 of this embodiment corresponds to a pressing tool.
The diameter reducing portion 313 corresponds to a diameter reducing means,
The groove processing portion 314 corresponds to the groove processing means,
The intermediate extraction portion 317 corresponds to the intermediate extraction device, but the present invention is not limited to the configuration of the third embodiment, and many embodiments can be obtained.

(Embodiment 4A)
Next, the manufacturing apparatus and manufacturing method of the inner surface grooved tube of Embodiment 4A will be described with reference to the drawings.
As shown in FIG. 13, the manufacturing apparatus 510 A for inner surface grooved pipes in Embodiment 4A has a diameter reduction processing section 513, a groove processing section 514, from the upstream side in the pipe axial direction X to the downstream side (the drawing direction). A diameter adjusting die 515 and a drawing part 516 (drawing part) are configured.
In addition, FIG. 13 is explanatory drawing of the manufacturing apparatus 510A of an internally grooved pipe | tube in this embodiment.

Further, the manufacturing apparatus 510A includes a machining-related data detection unit 517 that detects machining-related data related to a machining load that occurs in the pipe axis direction in accordance with the drawing of the raw pipe 511a, and the processing-related data detection when a disconnection occurs. A control unit 518 that determines that a disconnection has occurred based on the processing-related data detected by the unit 517 and outputs a drawing stop command to the drawing unit 516.

The diameter-reduction processing portion 513 includes a diameter-reducing die 522 and a floating plug 523 that is disposed in the element pipe 511a and reduces the diameter of the element pipe 511a together with the diameter-reducing die 522.

The diameter-reducing die 522 is formed in a cylindrical shape having a communication hole 522a that communicates with the tube axis direction X. The communication hole 522a has an upstream portion (inlet side) in the tube axis direction X as a downstream portion (outlet side). ) With respect to the upstream side.

The floating plug 523 is formed in a cylindrical shape, and the outer periphery of the downstream portion is formed in a tapered shape.

The grooved portion 514 is rotatably connected to the floating plug 523 via a plug rod 525 in the raw tube 511a, and has a grooved plug 524 having a plurality of grooves formed on the outer periphery, and an outer side of the raw tube 511a. In FIG. 5, a plurality of rolling balls 526 arranged to revolve around the tube axis while pressing the raw tube 511a toward the grooved plug 524, and a pressing treatment for pressing the rolled ball 526 toward the raw tube 511a. It is comprised with the tool 527.

The pressing jig 527 has a ring-shaped processing head 528 that holds the rolling ball 526 from the outer peripheral side, and has a sharp-angled conical inner peripheral surface that expands toward the downstream side in the tube axis direction X. And a ring-shaped pressing member 529 that applies a pressure to each rolling ball 526.

The plurality of rolling balls 526 are held by the inner peripheral surface of the processing head 528 as a rolling tool that can revolve while pressing the surface of the raw tube 511a in either the forward direction or the reverse direction. .

The diameter adjusting die 515 performs a process of smoothly adjusting the diameter of a tube surface caused by pressing of the rolling ball 526 in the groove processing portion 514 when the inner grooved tube 511 passes therethrough.

The drawing unit 516, combines the drawing drum 531 for winding the processed of the inner surface grooved tube 511 (winding drum), a motor M ₁ for driving the drawing drum 531, inner grooved by the rotation of the motor M ₁ The drawing tube 511 is wound around the drawing drum 531 while being pulled.

The machining-related data detection unit 517 is provided in the groove machining unit 514 and includes a groove machining load measurement load cell 541 for measuring the machining load in the groove machining unit 514 and a movable table 543.

The movable table 543 is configured to have a wheel at the lower part so as to be movable in the tube axis direction X with respect to the fixed table 542, and a pressing jig 527 for the groove processing portion 514 is installed at the upper part.
The groove processing load measuring load cell 541 is installed on the fixing jig 542a so as to be able to measure the processing load F in the tube axis direction X applied to the groove processing portion 514 via the movable table 543.

The control unit 518 receives a load detection signal S _in obtained by converting the load F detected from the grooving load measurement load cell 541 into an electrical signal, and determines that a disconnection has occurred according to a control program to be described later. It outputs a stop signal _{S out} to stop driving of the motor _{M 1} of the drawing portion 516 and.

Although not shown, the control unit 518 includes an arithmetic unit (CPU) for executing signal analysis processing and arithmetic processing, a hard disk for storing necessary control programs, and the load detection signal S _in for temporary storage. In addition, it is possible to appropriately include input means such as a keyboard for inputting control parameters and display means such as a monitor.

The inner grooved tube 511 can be manufactured by the manufacturing method described below using the manufacturing apparatus 510A described above.

First, a floating plug 523 and a grooved plug 524 rotatably connected to the floating plug 523 via a plug rod 525 are inserted into the raw tube 511a. The processing head 528 is rotated while the raw tube 511 a is pulled out through the reduced diameter die 522 and the processing head 528.
Note that a metal tube having good thermal conductivity such as copper, an alloy thereof, aluminum, or an alloy thereof can be used for the base tube 511a.

The raw tube 511a is reduced in diameter by the reduced diameter die 522 and the floating plug 523 along with the drawing. Next, a plurality of rolling balls 526 that revolve around the raw tube 511a as the machining head 528 rotates at the position of the grooved plug 524 presses the raw tube 511a. The peripheral surface is pressed against the surface of the grooved plug 524, and the groove 550 on the peripheral surface of the grooved plug 524 is transferred to the inner surface of the raw tube 511a.

Thereby, it is possible to form an internally grooved tube 511 having a large number of fine grooves 510 on the inner surface with a lead angle β (see FIG. 13) of 40 to 60 degrees with respect to the tube axis. Thereafter, the inner grooved tube 511 is adjusted in diameter by a downstream diameter adjusting die 515 and wound around the drawing drum 531.

In the manufacturing process of the inner grooved tube, the control unit 518 has a processing load F as processing related data detected by the groove processing load measurement load cell 541 when a disconnection occurs in the manufacturing process of the inner grooved tube 511 described above. Based on the above, it is determined that a disconnection has occurred, and control is performed to stop machining.

Specifically, the control unit 518 determines that a disconnection has occurred when the load detected by the load cell 541 for measuring a grooving load decreases to 20% or less during normal steady machining, and the motor M ₁ of the drawing unit 516 A control program for stopping driving is executed.

The manufacturing apparatus 510A can provide the following operational effects.
The manufacturing apparatus 510A is configured to be able to determine that a disconnection has occurred based on the processing load F detected by the groove processing load measurement load cell 541 provided in the groove processing section 514, and upstream of the diameter adjusting die 515, In particular, even when a disconnection occurs at the groove processing portion 514 or upstream thereof, it can be quickly and reliably determined that the disconnection has occurred.

Therefore, when the broken portion of the raw tube 511a passes through the groove processing portion 514 after the disconnection occurs, the rolling ball 526 directly presses the grooved plug 524 without passing through the raw tube 511a, and the grooved plug 524 Can be prevented from being damaged.

The manufacturing apparatus 510A performs control to determine that the tube is broken when the processing load F detected by the load cell 541 for measuring the grooving load during processing decreases to 20% or less of the processing load during normal steady processing. For this reason, it can be determined that the tube is broken when the load drops to the mechanical loss level.

Furthermore, since it is set in consideration of variations due to differences in properties among rods and environmental differences such as ambient temperature, the occurrence of disconnection will not be erroneously detected.

Therefore, when disconnection occurs, it is possible to reliably detect the occurrence of disconnection, and to manufacture a manufacturing apparatus with excellent production efficiency.

Further, the machining-related data detection unit 517 installs the groove machining unit 514 on the movable table 543, and loads the load in the tube axis direction X applied to the groove machining unit 514 via the movable table 543 to measure the groove machining load. Therefore, the load in the tube axis direction X applied to the groove machining portion 514 can be accurately measured.

Below, the

manufacturing apparatus

510B, 510C of the inner surface grooved pipe | tube in other embodiment is demonstrated.
However, among the configurations of the inner grooved

tube manufacturing devices

510B and 510C described below, the same reference numerals are given to the same configurations as the inner grooved tube manufacturing device 510A in the above-described embodiment 4A. The description is omitted.

(Embodiment 4B)
As shown in FIG. 14, the inner surface grooved pipe manufacturing apparatus 510 B according to the embodiment 4B is configured to reduce the diameter reducing portion 513, the groove processing portion 514, and the diameter adjusting die 515 along the tube axis direction X from the upstream side to the downstream side. The drawing unit 516 is configured, and a processing related data detection unit 545 and a control unit 546 are provided.
The machining-related data detection unit 545 includes a reduced-diameter machining load measurement load cell 545 that is provided in the reduced-diameter machining unit 513 and measures a machining load F in the reduced-diameter machining unit 513.
The diameter reduction load measuring load cell 545 is attached to the diameter reduction die 522 and can detect the load in the tube axis direction X applied to the diameter reduction die 522.

In addition, the inner surface grooved tube manufacturing apparatus 510B according to Embodiment 4B does not include the groove processing load measurement load cell 541 and the movable base 543 in the groove processing portion 514.

The control unit 546 is input to load F detected from diameter reduction load measuring load cell 545 is an electrical signal of the load detection signal S _in, in accordance with a control program, performs detection of the disconnection tube, when the cross-sectional tubes occurred, the cross-sectional tube outputs a stop signal S _out to stop driving of the motor M ₁ of the drawing unit 516 determines to have occurred.

Specifically, the control unit 546 determines that the tube is disconnected when the processing load F detected by the load cell 545 for measuring a reduced diameter processing load is reduced to 20% or less during normal steady processing, and determines the motor M ₁ of the drawing unit 516. A control program for stopping driving is executed.

The manufacturing apparatus 510B can provide the following operational effects.
The manufacturing apparatus 510 B is configured to determine that a disconnection has occurred based on the processing load F measured by the load cell 545 for measuring a diameter reduction load provided in the diameter reduction processing portion 513, and is upstream of the diameter adjusting die 515. Even when a disconnection occurs on the side, it can be quickly and reliably determined that the disconnection has occurred.

In particular, in the manufacturing apparatus 510B, when a tube break occurs on the downstream side of the reduced diameter processing portion 513, the load applied to the reduced diameter processing portion 513 becomes zero due to the drawing of the raw tube simultaneously with the occurrence of the disconnection, It can be immediately determined that a disconnection has occurred.

Therefore, it is possible to prevent the rolled ball 526 from pressing the grooved plug 524 directly without passing through the raw tube 511a and damaging the grooved plug 524.

(Embodiment 4C)
As shown in FIG. 15, the inner surface grooved pipe manufacturing apparatus 510 C according to Embodiment 4C has a diameter reduction processing part 513 and an intermediate drawing part 551 (intermediate drawing part) along the pipe axis direction X from the upstream side to the downstream side. , A groove processing unit 514, a diameter adjusting die 515, and a drawing unit 516, and a processing related data detection unit 552 and a control unit 553 are provided.
FIG. 15 is an explanatory diagram of an inner grooved tube manufacturing apparatus 510C according to Embodiment 4C.

The intermediate drawing portion 551 assists the drawing by the drawing portion 516 by drawing the raw tube 511a in the tube axis direction X between the reduced diameter portion 513 and the groove processing portion 514. That is, the grooving by the grooving portion 514 becomes resistance when the raw tube 511a is drawn, and the drawing (drawing) load at the time of grooving increases, but the intermediate drawing portion 551 applies to the raw tube 511a. The drawing load can be dispersed in the tube axis direction X, and as a result, the load applied to the groove processing portion 514 can be reduced.

The intermediate drawing portion 551 includes a pair of belts 554 arranged on the upper and lower sides or the left and right sides with respect to the raw tube 511a. Each belt 554 is stretched by the pulley 5555 in a loop (endless) is configured to be rotated by the motor M _2. The belt 554 has a plurality of pads 556 connected to the outer peripheral surface along the length direction.

Although not shown, the pad 556 is formed with a pad groove in which the cut surface with respect to the connecting direction of the plurality of pads 556 has an arcuate shape at the contact portion with the outer surface of the base tube 511a after the diameter reduction by the diameter reducing portion 513. is doing.

The intermediate drawing unit 551 presses the pad 556 to the base pipe 511a surface by driving of the motor _{M 3,} or are retractably configuration.
A wiper 557 is provided on the upstream side of the intermediate drawing portion 551 to remove an oil film and foreign matter adhering to the outer surface of the raw pipe 511a, and an intermediate diameter adjusting die 558 is provided on the downstream side.

The wiper 557 is provided to remove an oil film and foreign matter adhering to the outer surface of the raw tube 511a, and has a through hole having a diameter slightly smaller than the outer diameter of the raw tube 511a in order to pass through the raw tube 511a. For example, a rubber cylindrical body formed in the central portion.
The intermediate diameter adjusting die 558 is provided to return the cross-sectional shape of the flat tube 511a flattened by the intermediate drawing portion 551 to a shape close to a perfect circle, and the diameter of the reduced diameter die 522 is changed according to the shape of the raw tube 511a. It is configured with the same or smaller die diameter.
The control unit 553, by controlling the driving of the motor _{M 3} of the intermediate drawing unit 551 can control the pressing force against the base pipe 511a by the pad 556 of the intermediate drawing section 551.
By pressing the pad 556 against the base tube 511a with an appropriate pressing force, the slip between the pad 556 and the base tube 511a is reduced, and the fluctuation of the load F is reduced.

The processing related data detection unit 552 is an ammeter 552 that detects a current value (electrical signal) corresponding to a driving force command value to the motor M ₃ as a signal related to the driving force of the motor M ₃ of the intermediate drawing unit 551. It is composed.
The manufacturing apparatus 510C does not include the groove processing load measurement load cell 541 and the movable base 543 in the groove processing portion 514, and does not include the load cell 545 for diameter reduction processing load measurement in the diameter reduction processing portion 513. .

Further, as described above, the control unit 553 includes a calculation unit that differentiates the current value detected by the ammeter 552, and includes a storage unit that stores the differential value as load-related data. Further, the control unit 553, when the differential value varies significantly beyond 5σ variations of steady state processing, determines that the cross tube, the motor M ₁ of the drawing unit _516, the motor M ₃ of the intermediate drawing section 551 A control program for outputting a drawing stop command is provided.

The internally grooved tube 511 can be manufactured using the manufacturing apparatus 510C described above.
In the control unit 553, when the raw tube 511a is broken, it is determined that the disconnection has occurred based on the differential value obtained by differentiating the current value detected by the ammeter 552, and the processing is stopped.
Specifically, according to the manufacturing method of the inner surface grooved tube 511, the amount of change in the differential value obtained by differentiating the current value detected by the ammeter 552 is measured, and when the fluctuation exceeds 5σ, it is determined that the tube is broken, and the drawing unit motor _{M 1} 516, to stop the device, such as a motor _{M 2} of the intermediate drawing section 551.

The manufacturing apparatus 510 C can provide the following operational effects.
The manufacturing apparatus 510 C can reliably detect a broken tube generated upstream of the diameter adjusting die 515 before the grooved plug 524 is damaged.

Furthermore, since the manufacturing apparatus 510C can determine that a disconnection has occurred based on a differential value obtained by differentiating a current value that is a command value of the motor load (driving force) of the intermediate drawing unit 551, the intermediate drawing unit 551 Even under a situation in which the load fluctuation is large due to the drawing assistance of the portion 551, it is possible to quickly and reliably detect the disconnection that has occurred on the upstream side of the intermediate drawing portion 551 or the intermediate drawing portion 551.

Furthermore, based on the differential value of the current value corresponding to the load of the motor M ₂ of the intermediate drawing unit 551, since it is determined configuration to the cross-sectional tubes occurred, the load cell and torque gauge, further, for installing these It is not necessary to add hardware such as a movable table, and for example, disconnection can be detected by simple hardware such as an ammeter 552.

In addition, 510 C of inner surface grooved pipe manufacturing apparatuses of Embodiment 4C are not restricted to the structure which detects a disconnection based only on the said process related data detection part 552 (ammeter 552) with which the intermediate | middle drawing part 551 was equipped.
Specifically, in addition to the processing-related data detection unit 552, the manufacturing apparatus 510C includes a groove processing load measurement load cell 541 in the groove processing unit 514 and / or a diameter reducing processing load measurement load cell 545 in the diameter reduction processing unit 513. It does not exclude the configuration for detecting the occurrence of disconnection at each location.

(Example 16)
Subsequently, when the tube 511a (inner surface grooved tube 511) is disconnected during the processing of the inner surface grooved tube 511 using the manufacturing apparatus of the present invention, the grooved plug 524, which is difficult to substitute, is not damaged. An experiment for detecting the disconnection was conducted to verify whether or not the occurrence of the disconnection can be determined.
In this disconnection detection experiment, the

manufacturing apparatuses

510A, 510B, and 510C of Embodiments 4A to 4C are used as the manufacturing apparatus of the present invention, and the related art is used as a comparative example of the

manufacturing apparatuses

510A, 510B, and 510C of Embodiments 4A to 4C. This was performed using the manufacturing apparatus according to the above.

In the

manufacturing apparatuses

510A, 510B, and 510C of the embodiments 4A to 4C, as described above, all of them are more in the tube axial direction X upstream side than the drawing portion 516, more specifically in the groove processing portion 514 or the groove processing portion 514. The processing

load detection units

517, 545, and 552 are provided as appropriate, and the processing

load detection units

517, 545, and 552 detect processing load related data. Table 11 and FIG. 16 summarize the presence / absence of installation of the intermediate drawing unit 551, the type of the processing

load detection units

517, 545, and 552, and the installation location of the intermediate drawing unit 551 for the

manufacturing apparatuses

510A, 510B, and 510C of Embodiments 4A to 4C. As shown in FIG.

In addition, Table 11 is a table | surface which shows the presence or absence of installation of the intermediate | middle drawing part 551 of each manufacturing apparatus of Embodiment 4A to 4C, the kind of process load detection part, and the installation location of an intermediate | middle drawing part.
FIG. 16 is a schematic diagram of a manufacturing apparatus in which the processing load detection unit is installed in each of the manufacturing apparatuses of Embodiments 4A and 4B and the comparative example, and the intermediate drawing unit is not installed. FIG. 17 is a schematic diagram of a manufacturing apparatus in which an intermediate drawing unit is installed, showing the installation location of the processing load detection unit installed in the manufacturing apparatus of Embodiment 4C.

On the other hand, as shown in Table 11 and FIG. 16, in the manufacturing apparatus of the comparative example, a configuration in which the intermediate drawing unit 551 is not installed is taken as an example, and the load detector that detects the load of the motor of the drawing drum 531 on the drawing unit 516. (Not shown), the drawing load is detected by the load detector.

Moreover, the disconnection generation | occurrence | production location (henceforth "the disconnection location") was made into nine places of the disconnection location a to i as shown in FIG. 16, FIG.
The disconnection points a to d are as shown in FIG. 16. Specifically, the disconnection point a is between the diameter adjusting die 515 and the drawing part 516, and the disconnection point b is within the diameter adjusting die 515. Or it is between the groove processing part 514 and the diameter adjustment die 515, and the disconnection part c is in the groove processing part 514 or between the diameter reduction processing part 513 and the groove processing part 514, and the disconnection part d is , Between the payoff table 562 for supplying the raw pipe 511a from the inside of the reduced diameter processing portion 513 or from the upstream side of the reduced diameter processing portion 513 and the reduced diameter processing portion 513.

The disconnection points e to i are as shown in FIG. 17. Specifically, the disconnection point e is between the diameter adjusting die 515 and the drawing part 516, and the disconnection point f is within the diameter adjusting die 515. Or it is between the groove processing part 514 and the diameter adjusting die 515, the disconnection part g is in the groove processing part 514 or between the intermediate drawing part 551 and the groove processing part 514, and the disconnection part h is Between the reduced diameter processing portion 513 and the intermediate drawing portion 551, the disconnection point i is in the reduced diameter processing portion 513 or between the payoff table 562 and the reduced diameter processing portion 513.

Based on the above, the disconnection detection experiments 0-a, 0-b are respectively performed when the disconnection occurs at each of the disconnection locations a, b, c, d using the manufacturing apparatus of the comparative example. , 0-c, 0-d. The disconnection detection experiments 1-a, 1-b, and 1 are respectively performed when the disconnection occurs at each of the disconnection locations a, b, c, and d using the manufacturing apparatus 510A of Embodiment 4A. -C, 1-d. The disconnection detection experiments 2-a, 2-b, and 2 are performed when the disconnection occurs at each of the disconnection points a, b, c, and d using the manufacturing apparatus 510B of Embodiment 4B. -C, 2-d. The disconnection detection experiment 3-e, 3-f is performed when the disconnection occurs at each of the disconnection locations e, f, g, h, i using the manufacturing apparatus 510C of Embodiment 4C. , 3-g, 3-h, 3-i.

The disconnection detection control performed in the disconnection detection experiment will be described with reference to FIGS.
FIG. 18 to FIG. 29 are graphs showing the relationship between the machining load and time detected by the machining load detection unit appropriately provided in each machining unit in each disconnection detection experiment. It is assumed that a disconnection has occurred when the second has elapsed.

Furthermore, since the apparatus is stopped as soon as it is determined that a disconnection has occurred after the detection of the disconnection, the subsequent load becomes zero. However, in FIGS. 18 to 29, the change in the load before and after the disconnection is detected. In order to show the situation, a waveform of a load in a state where the apparatus is not stopped even after the apparatus is actually stopped is shown.

(A disconnection detection experiment using the manufacturing apparatus of the comparative example)
In the manufacturing apparatus of the comparative example, as shown in FIG. 18 to FIG. 21, the threshold value is a value that is reduced by a ratio of 20% with respect to the drawing load of the motor M ₁ at the time of steady processing of the drawing drum 531 described above. Set to tube detection line.
FIGS. 18 to 21 show the experimental results of the disconnection detection experiments in the disconnection detection experiments 0-a, 0-b, 0-c, and 0-d, respectively.

The disconnection detection line needs to be set within a range where it is possible to determine that the disconnection has occurred and to prevent the disconnection from being erroneously detected.
Specifically, the drawing load of the drawing drum 531 fluctuates within a range of about ± 50 N within a machining time range of several hundred seconds as shown in FIG. Paying attention to the machining time range of several hundreds of minutes between the beginning and end of the lot, the load of the drawing drum 531 is further increased due to the difference in the annealing state before and after the copper pipe, uneven thickness, wear of the grooved plug 524, etc. There will be fluctuations.

Furthermore, the difference between the lots of copper pipes, the difference in the solids of the grooved plug 524, and the difference due to seasonal variation are larger. For example, the drawing load of the drawing drum 531 is about It fluctuates in the range of 1500N to 3000N.

Therefore, if the disconnection detection line is raised as a threshold for disconnection detection, erroneous detection of the occurrence of disconnection increases. Therefore, it is necessary to set the disconnection detection line within a range in which erroneous detection of disconnection does not occur.

The result of the disconnection detection experiment 0-a is as shown in FIG. As shown in FIG. 18, until the cross tube occurs, drawing load drawing drum 531, although shifted in the range of steady state processing, simultaneously with the cross tube occurs, drawing load of the motor M ₁ is than the cross tube detection line Since the mechanical loss level is lowered to a low mechanical loss level, it is possible to prevent the grooved plug 524 from being damaged by the rolled ball 526 by determining that the disconnection has occurred simultaneously with the occurrence of the disconnection and stopping the apparatus.

The result of the disconnection detection experiment 0-b is as shown in FIG. As shown in FIG. 19, the drawing load of the drawing drum 531 drops at the same time as the disconnection occurs, but does not fall below the disconnection detection line (see point a of the load waveform in FIG. 19), and the fracture portion is At the same time as passing through the diameter adjusting die 515, the drawing load of the drawing drum 531 falls to a mechanical loss level lower than the broken tube detection line, so the control unit determines that the tube is broken and stops the apparatus.

Thus, even in the disconnection detection experiment 0-b, the manufacturing apparatus of the comparative example can stop processing after the occurrence of the disconnection, but there is a slight delay between the occurrence of the disconnection and the detection of the disconnection. become.

However, in the disconnection detection experiment 0-b, since the disconnection occurs at the disconnection location b downstream of the groove processing portion 514, the fracture portion passes through the groove processing portion 514 having the grooved plug 524. The device can be stopped before the fluted plug 524 breaks.

If the disconnection detection line is set higher than the load value that drops simultaneously with the occurrence of the disconnection (see point a of the load waveform in FIG. 19), the disconnection occurs before the fractured portion passes through the diameter adjusting die 515. However, as described above, as the drawing load fluctuates during processing due to various factors, false detection of disconnection is likely to occur, and processing efficiency is greatly reduced. It is not preferable.

The result of the disconnection detection experiment 0-c is as shown in FIG. As shown in FIG. 20, the drawing load of the drawing drum 531 drops at the same time as the disconnection occurs, but drops step by step every time the fractured portion passes through the groove processing portion 514 and the diameter adjusting die 515, and the fractured portion Until the diameter passes through the sizing die 515, the drawing load does not drop to a mechanical loss level lower than that of the disconnection detection line, and the controller determines that the disconnection has occurred until it finally passes through the sizing die 515. I can't.

Therefore, the disconnection occurs at the disconnection location c that is upstream of the groove processing portion 514, but it is determined that the disconnection has occurred after the disconnection has occurred, and there is a delay in the time required to stop the apparatus. Therefore, during this time, the fractured portion passes through the grooved portion 514 having the grooved plug 524, and the rolling ball 526 directly contacts the grooved plug 524, so that the grooved plug 524 may be damaged.

Note that points a and b in the waveform of the drawing load in FIG. 20 indicate that the fracture portion is passing through the groove processing portion 514 and the diameter-controlling die 515, respectively.

The result of the disconnection detection experiment 0-d is as shown in FIG. As shown in FIG. 21, the drawing load of the drawing drum 531 drops at the same time as the occurrence of the broken tube, as in the broken tube detection experiment 0-c, but the fractured portion is the reduced diameter processed portion 513, the groove processed portion 514, Each time it passes through the diameter die 515, it is lowered step by step, and the drawing load does not drop to a mechanical loss level lower than that of the disconnection detection line until it passes through the diameter adjustment die 515. It is not possible to determine that a disconnection has occurred until it passes.

Therefore, it is determined that the disconnection has occurred after the occurrence of the disconnection, and there is a delay in the time required to stop the apparatus. During this time, the rolling ball 526 contacts the grooved plug 524, so that the grooved plug 524 may be damaged. There is.

(A disconnection detection experiment using the manufacturing apparatus of Embodiment 4A)
Subsequently, a disconnection detection experiment using the manufacturing apparatus 510A of Embodiment 4A will be described.
In the manufacturing apparatus 510A of Embodiment 4A, the disconnection detection line is set to be 20% of the measurement load (processing load F) at the time of steady machining measured by the grooving load measuring unit 517 as a threshold for detecting the disconnection, When the measured load falls below the broken tube detection line, it is determined that the tube is broken, and control is performed to stop the apparatus.

The result of the disconnection detection experiment 1-a is as shown in FIG. As shown in FIG. 22, since the measurement load of the groove processing load measuring unit 517 falls to zero, the measurement load is lower than the disconnection detection line simultaneously with the occurrence of the disconnection, it is determined that the disconnection has occurred immediately. Yes, the device can be stopped without damaging the fluted plug 524.

Note that the measured load drops to zero after the disconnection when the disconnection occurs on the downstream side of the groove processing portion 514. When the disconnection occurs, the drawing of the raw pipe 511a by the drawing drum 531 occurs simultaneously with the generation of the disconnection. This is because it does not work completely up to 514.

Similarly to the disconnection detection experiment 1-a, the disconnection detection experiment 1-b can detect the disconnection immediately because the measurement load drops to zero as soon as the disconnection occurs. The device can be shut down without damaging 524.
Note that the measurement load of the grooving load measurement unit 517 in the disconnection detection experiment 1-b has substantially the same waveform as that in FIG. 22, and thus a graph showing the relationship between the machining load and the elapsed time is omitted.

The result of the disconnection detection experiment 1-c is as shown in FIG. As shown in FIG. 23, the measurement load of the grooving load measurement unit 517 does not drop simultaneously with the occurrence of the broken tube.
This is because, when a disconnection occurs at the disconnection point c that is upstream of the groove processing portion 514, even if the disconnection occurs until the fractured portion passes the groove processing portion 514, the raw pipe by the drawing drum 531 This is because the drawing of 511a acts up to the groove processing portion 514.

At the same time that the cut-off portion has passed through the groove processing portion 514 (see point a of the load waveform in FIG. 23), the control portion descends to zero, which is lower than the cut-off detection line. Determine and stop the device.

As described above, in the manufacturing apparatus 510A of Embodiment 4A, in the case of the disconnection location c, the apparatus cannot be stopped simultaneously with the occurrence of the disconnection, but the disconnection has occurred at the same time as the fracture portion passes the groove processing portion 514. Since the determination and the apparatus can be stopped immediately, it is possible to prevent the grooved plug 524 from being damaged.

Here, in the manufacturing apparatus of the comparative example, as described in the disconnection detection experiment 0-c, when the disconnection occurs at the disconnection location c, the fracture portion passes through the groove processing portion 514, and further the diameter adjusting die. It cannot be determined that the disconnection has occurred until it passes through 515 (see FIG. 20). That is, the rolling ball 526 comes into contact with the grooved plug 524 for a few seconds while the fracture portion passes between the groove processing portion 514 and the diameter adjusting die 515 and passes through the diameter adjusting die 515, and the groove The plug 524 will be damaged.

On the other hand, in the manufacturing apparatus 510A of the embodiment 4A, when the disconnection occurs at the disconnection point c, the fracture portion is between the groove processing part 514 and the diameter adjusting die 515 and the diameter adjusting die compared to the manufacturing apparatus of the comparative example. Since the apparatus can be stopped quickly only while passing through 515, it is possible to prevent the grooved plug 524 from coming into contact with the rolled ball 526 and being damaged.

Also in the disconnection detection experiment 1-d, as shown in FIG. 24, the manufacturing apparatus 510A of Embodiment 4A cannot determine that the disconnection has occurred simultaneously with the occurrence of the disconnection, but the fracture portion is reduced in diameter. When passing through the portion 513 and passing through the groove processing portion 514, the measurement load of the groove processing load measurement portion 517 drops to zero (see point a in the load waveform in FIG. 24), so the passage through the groove processing portion 514 At the same time, it can be determined that the disconnection has occurred, and it is possible to prevent the grooved plug 524 from being damaged in the same manner as in the disconnection detection experiment 1-c.

(A disconnection detection experiment using the manufacturing apparatus of Embodiment 4B)
Subsequently, a disconnection detection experiment using the manufacturing apparatus 510B of Embodiment 4B will be described.
In the disconnection detection experiment 2-a, similar to the disconnection detection experiment 1-a, a disconnection is generated on the downstream side of the groove processing portion 514. Therefore, the drawing pipe 511a is drawn by the drawing drum 531 simultaneously with the disconnection. It does not work up to the reduced diameter processing portion 513.

For this reason, as shown in FIG. 25, the measurement load of the reduced diameter processing load measuring unit drops to zero at the same time that the measured load falls to zero, which is lower than the broken line detection line, and the occurrence of broken pipe immediately. The determination can be made, and the apparatus can be stopped without damaging the grooved plug 524.

Similarly, in the disconnection detection experiments 2-b and 2-c, since the measurement load drops to zero at the same time as the occurrence of the disconnection, it can be immediately determined that the disconnection has occurred, and the grooved plug 524 is damaged. Without stopping the device.
Note that the measurement load of the groove processing load measuring unit 517 in the disconnection detection experiments 2-b and 2-c has substantially the same waveform as that in FIG. 25, and therefore the graph showing the relationship between the processing load and the elapsed time is omitted. To do.

In the disconnection detection experiment 2-d, since the disconnection occurs at the disconnection location d upstream of the diameter reduction processing portion 513, the fracture portion passes through the diameter reduction processing portion 513 even if the disconnection occurs. Until then, the drawing of the tube 511a by the drawing drum 531 acts up to the reduced diameter processing portion 513.

For this reason, as shown in FIG. 26, the measurement load of the reduced diameter processing load measuring portion does not drop at the same time as the occurrence of the disconnection, but is lower than the disconnection detection line at the same time as the broken portion passes the reduced diameter processing portion 513. The controller descends to zero, and the control unit determines that a disconnection has occurred and stops the apparatus.

As described above, in the manufacturing apparatus 510B of Embodiment 4B, the apparatus cannot be stopped simultaneously with the occurrence of the disconnection, but it is determined that the disconnection has occurred at the same time as the fractured portion passes through the reduced diameter processing portion 513, and the fractured portion is Since the apparatus can be stopped before passing through the grooved portion 514, it is possible to prevent the grooved plug 524 from being damaged.

(A disconnection detection experiment using the manufacturing apparatus of Embodiment 4C)
Subsequently, a disconnection detection experiment using the manufacturing apparatus 510C of Embodiment 4C will be described.
In the manufacturing apparatus 510C embodiments 4C, it is determined as the cross-sectional tube a differential value of the load of the motor M ₂ of the intermediate drawing section 551 based on occurs as described above.
For more information, monitors the load of the motor M ₂ of the intermediate drawing section 551 the amount of change (drawing load F of the intermediate drawing section 551) (differential value), the variation of the differential value is determined as the cross-sectional tube Once beyond the 5Shiguma, device The control which stops is performed.

Here, the drawing load in the intermediate drawing unit 551 is actually due to various factors such as the state of the raw pipe 511a (copper pipe) before the machining, the state of the apparatus, and the machining environment even during the steady machining. The amount of change increases.

For this reason, it is preferable in that the disconnection can be accurately determined by detecting the occurrence of the disconnection using the differential value of the drawing load as in the manufacturing apparatus 510C of the embodiment 4C.

The experimental result of the disconnection detection experiment 3-e is as shown in FIG.
FIG. 27 is a graph showing the drawing load and the amount of load change (differential value) in the intermediate drawing unit 551 before and after the occurrence of the broken tube, and the drawing load is plotted on the left side in FIG. The amount of change in the load is indicated on the right side in FIG.

In the disconnection detection experiment 3-e, a disconnection occurs downstream of the groove processing portion 514. This increases the load on the intermediate drawing portion 551, and the amount of change in the drawing load of the drawing drum is the same as that during steady processing. It is remarkable compared. Therefore, it can be determined that the disconnection has occurred substantially simultaneously with the occurrence of the disconnection, and the apparatus can be stopped.

As shown in FIG. 27, when viewed in the range of several hundred seconds, there is no great difference in the variation of the drawing load in the intermediate drawing unit 551 and the variation of the differential value of the drawing load. If it sees in the range of a minute level, the fluctuation | variation of the drawing load in the intermediate drawing part 551 will become large.

For this reason, it is determined that a disconnection has occurred based on the amount of change (differential value) of the drawing load of the intermediate drawing unit 551, so that the disconnection is immediately generated simultaneously with the disconnection without erroneously detecting the disconnection. The determination can be made, and the apparatus can be stopped without damaging the grooved plug 524.

Similarly to the disconnection detection experiment 3-e, the disconnection detection experiments 3-f and 3-g have a change amount (differential value) of the drawing load of the intermediate drawing portion 551 exceeding 5σ at the same time as the occurrence of the disconnection. The disconnection can be detected immediately, and the apparatus can be stopped without damaging the grooved plug 524.

Note that the measurement load of the intermediate drawing portion 551 in the disconnection detection experiments 3-f and 3-g has substantially the same waveform as that in FIG. 27, and thus the graph showing the relationship between the machining load and the elapsed time is omitted.

In the disconnection detection experiment 3-h, a disconnection occurs in the intermediate drawing portion 551 or at a disconnection location h upstream of the intermediate drawing portion 551. As shown in FIG. The amount of change (differential value) in the drawing load of the drawing unit 551 changes until it exceeds 5σ, and it can be immediately determined that disconnection has occurred, and the apparatus can be stopped without damaging the grooved plug 524.

In the broken tube detection experiment 3-i, as shown in FIG. 29, the load of the intermediate drawing portion 551 and the change amount (differential value) of the intermediate drawing portion 551 do not drop as soon as the broken tube is generated. Since the disconnection occurs at the disconnection location i upstream of the diameter reducing portion 513, the drawing load of the intermediate drawing portion 551 is not affected until the fracture portion passes the diameter reducing portion 513. Because.

However, at the same time that the fractured portion passes through the reduced diameter processing portion 513, the amount of change (differential value) in the load of the intermediate drawing portion 551 changes in the same manner as the disconnection detection experiment 3-h until the occurrence of disconnection occurs. The determination can be made, and the apparatus can be stopped without damaging the grooved plug 524.

According to the disconnection detection experiment described above, in the manufacturing apparatus of the comparative example, the grooved plug 524 was directly pressed against the rolled ball 526 and was damaged depending on the location where the disconnection occurred.

In contrast, each of the manufacturing apparatuses of Embodiments 4A to 4C determines that a tube break has occurred during processing before the grooved plug 524 is damaged by the rolled ball 526, and stops processing. I was able to.

Therefore, it has been proved that the grooved plug 524 can be prevented from being damaged by the inner grooved tube manufacturing apparatus and method of the present invention.

In the correspondence between the above-described Embodiment 4 and the configuration of the present invention, the diameter-reduction processing portion 513 of this embodiment corresponds to the diameter-reducing means of the present invention.
The groove processing portion 514 corresponds to the groove processing means,
The drawing unit 516 corresponds to drawing means,
The intermediate drawing unit 551 corresponds to the intermediate drawing means,
The measurement load measured by the machining-related

data detection units

517 and 545 or the current measured by the ammeter 552 corresponds to the machining-related data,
Processing-related

data detection units

517, 545, 552 correspond to processing-related data detection means,

Control units

518, 546, and 553 including a calculation unit and a storage unit correspond to the disconnection determination unit,
The groove processing load measuring load cell 541 corresponds to the groove processing load measuring means,
The diameter reducing load measuring load cell 545 corresponds to the diameter reducing load measuring means,
The differential value of the drawing load of the intermediate drawing unit 551 corresponds to the load related data,
The calculation unit of the ammeter 552 and the control unit 553 corresponds to the load-related data detection means, but the present invention is not limited to the configuration of the above-described fourth embodiment, and many embodiments are obtained. Can do.

Claims

When the twist angle of the groove with respect to the central axis of the tube is β (degrees) and the apex angle of the fin formed between adjacent grooves is α (degrees),
β is 30 to 60, α is 5 to 20,
When the outer diameter is D (mm), the groove depth is H (mm), and the cross-sectional area with respect to the axial direction of the tube is A C (mm 2 ),
An internally grooved tube in which D is 6 or less, H is 0.07 or more, and A C <0.8 × D.
The internally grooved tube according to claim 1, wherein the outer diameter D (mm) is 3 or more.
The inner grooved tube according to claim 1 or 2, wherein a depth H (mm) of the groove is 0.10 to 0.30.
An inner grooved tube manufacturing method using an inner surface grooved tube manufacturing apparatus comprising a diameter reducing means for drawing and reducing a diameter of an element tube and a groove processing means for forming a plurality of grooves on the inner surface of the element tube.
In the manufacturing apparatus of the inner grooved tube,
A drawing means that also serves as a winding drum for winding the internally grooved pipe that has been processed downstream of the groove processing means; and an auxiliary drawing means that draws the raw pipe between the diameter reducing means and the groove processing means. , A movable means that supports the diameter reducing means, the auxiliary drawing means, and the grooving means, and is movable in the drawing direction with respect to the installation portion, and a machining load that acts in accordance with the movement of the movable means with respect to the installation portion Load detecting means for detecting the control, and control means for controlling the auxiliary pulling means based on the processing load detected by the load detecting means,
When the twist angle of the groove with respect to the central axis of the tube is β (degrees) and the apex angle of the fin formed between adjacent grooves is α (degrees), β is 30 to 60 and α is 5 to 20 When the outer diameter is D (mm), the groove depth is H (mm), and the cross-sectional area with respect to the axial direction of the tube is A C (mm 2 ), D is 6 or less and H is 0.07 or more. And A C <0.8 × D, the processing load is P (N), the cross-sectional area of the tube after passing through the grooving means is A C1 (mm 2 ), and after passing through the grooving means. When the breaking stress of the tube is σ M (N / mm 2 ),
The method for producing an internally grooved tube according to claim 4, wherein the auxiliary drawing means is controlled so that P is between 0.5 times and 0.9 times (A C1 × σ M ).
6. The method for producing an internally grooved tube according to claim 5, wherein the outer diameter D (mm) is 3 or more.
The method for producing an internally grooved tube according to claim 5 or 6, wherein the depth H (mm) of the groove is 0.10 to 0.30.
The inner surface grooved pipe manufacturing apparatus includes the diameter reducing means, the groove processing means, and a drawing means for pulling out the grooved inner grooved pipe in this order from the upstream side.
Feed assisting means provided between the diameter reducing means and the groove machining means, and assisting the feeding of the reduced diameter tube in a feed direction toward the groove machining means;
A moving table in which the diameter reducing means and the feed assisting means are fixed and movable relative to the groove machining means in parallel with the drawing direction of the drawing means;
A base on which the groove processing means is fixed and movable relative to the drawing means in parallel with the drawing direction;
A moving table load detecting device for detecting a load in the relative moving direction applied to the moving table when the moving table moves relative to the groove processing means;
A base load detection device that detects a load in the relative movement direction applied to the base when the base moves relative to the pulling means;
And a control means for controlling the operation of the feed assist means,
The moving table is configured to be movable relative to the base in the pulling direction,
The control means
At least one of the feed assist speed of the feed assist means and the feed assist torque of the feed assist means is adjusted based on a difference between loads detected by the moving table load detecting device and the base load detecting device. Item 5. A method for producing an internally grooved tube according to Item 4.
The feed assist speed adjusted by the control means is the first feed assist speed,
The method for manufacturing an internally grooved pipe according to claim 8, wherein the feed assist torque adjusted by the control means is controlled to be adjusted with a second feed assist speed determined based on a correlation with the feed assist torque.
Using the inner grooved pipe manufacturing apparatus,
In the process of moving the pipe in the drawing direction, a diameter reducing process for reducing the diameter of the pipe, and a groove forming process for forming a plurality of grooves on the inner surface of the pipe, the diameter reducing process and the groove processing process are performed. While performing, an intermediate drawing process is performed to pull out the raw pipe reduced in diameter in the diameter reducing process,
The diameter reduction processing step is performed with a diameter reduction die and a floating plug that is arranged in the element pipe and reduces the diameter of the element pipe together with the diameter reduction die,
In the groove processing step, a grooved plug that is rotatably connected to the floating plug in the raw tube and has a plurality of grooves formed on the outer periphery thereof, and the raw tube on the outer side of the raw tube toward the grooved plug. A method for manufacturing an internally grooved tube with a pressing tool arranged to revolve around a tube axis while pressing,
By the outer diameter D o (mm) of the raw tube and the diameter D 2 (mm) of the reduced diameter die,
R D = {(D o −D 2 ) / D o } × 100 (%)
The diameter reduction ratio R D (%) of the elemental tube expressed by
Set R D ≦ 30,
The outer diameter D 1 (mm) of the floating plug and the diameter D 2 (mm) of the reduced diameter die are as follows:
D 1 -D 2 ≧ 0.1
The manufacturing method of the internally grooved tube according to claim 4, which is set to be
The revolution direction of the pressing tool is set to be opposite to the rotation direction of the grooved plug,
The processing pitch P (mm) of the pressing tool is
0.2 ≦ P ≦ 0.7
The method for producing an internally grooved tube according to claim 10, wherein the inner grooved tube is set so as to fall within a range of
The revolution direction of the pressing tool is set to the same direction as the rotation direction of the grooved plug,
The processing pitch P (mm) of the pressing tool is
0.2 ≦ P ≦ 0.4
The method for producing an internally grooved tube according to claim 10, wherein the inner grooved tube is set so as to fall within a range of
A diameter reducing means for reducing the diameter of the raw tube;
An apparatus for manufacturing an internally grooved tube, comprising groove processing means for performing groove processing on an inner surface of a reduced diameter reduced tube.
The diameter reducing means, the groove processing means, and a drawing means for pulling out the grooved inner grooved tube are provided in this order from the upstream side,
An apparatus for producing an internally grooved pipe provided with a feed assisting means provided between the diameter reducing means and the groove machining means and assisting in feeding the reduced diameter pipe in a feeding direction toward the groove machining means,
A moving table in which the diameter reducing means and the feed assisting means are fixed and movable relative to the groove machining means in parallel with the drawing direction of the drawing means;
The inner surface grooved tube according to claim 13, further comprising a moving table load detecting device that detects a load in the relative moving direction applied to the moving table when the moving table moves relative to the groove processing means. Manufacturing equipment.
A base on which the groove processing means is fixed and movable relative to the drawing means in parallel with the drawing direction;
A base load detection device that detects a load in the relative movement direction applied to the base when the base moves relative to the pulling means;
Control means for controlling the operation of the feeding auxiliary means,
The movable table is configured to be movable relative to the base in the pulling direction, and
The control means is
A feed assist speed adjustment process for adjusting a feed assist speed of the feed assisting means based on a load detected by at least one of the moving table load detecting device and the base load detecting device, and a feed assist torque of the feed assisting means The apparatus for manufacturing an internally grooved tube according to claim 14, wherein at least one of feed auxiliary torque adjustment processing for adjusting the pressure is executed.
The feed assist speed in the assist speed adjustment process is the first feed assist speed,
The feed assist torque adjustment process
The inner grooved pipe manufacturing apparatus according to claim 15, wherein the adjusting process is performed by adjusting with a second feed assist speed determined based on a correlation with the feed assist torque.
An intermediate in which the diameter reducing means and the groove processing means are provided along the drawing direction of the element pipe, and the diameter reduced by the diameter reducing means is drawn between the diameter reducing means and the groove processing means. With a pull-out section,
The diameter-reducing means is constituted by a diameter-reducing die and a floating plug that is disposed in the raw tube and reduces the diameter of the raw tube together with the diameter-reducing die,
The groove processing means is rotatably connected to the floating plug in the raw tube, and has a grooved plug in which a plurality of grooves are formed on the outer periphery, and the raw tube is moved to the grooved plug side outside the raw tube. An inner grooved pipe manufacturing apparatus configured with a pressing tool arranged to revolve around a pipe axis while pressing,
By the outer diameter D o (mm) of the raw tube and the diameter D 2 (mm) of the reduced diameter die,
R D = {(D o −D 2 ) / D o } × 100 (%)
The diameter reduction ratio R D (%) of the elemental tube expressed by: R D ≦ 30 in the diameter reduction means
Set to
The outer diameter D 1 (mm) of the floating plug and the diameter D 2 (mm) of the reduced diameter die are as follows:
D 1 -D 2 ≧ 0.1
The apparatus for manufacturing an internally grooved tube according to claim 13, which is set to be
The revolution direction of the pressing tool is set to be opposite to the rotation direction of the grooved plug,
The processing pitch P (mm) of the pressing tool is
0.2 ≦ P ≦ 0.7
The apparatus for manufacturing an internally grooved tube according to claim 17, which is set to fall within the range of
The revolution direction of the pressing tool is set to the same direction as the rotation direction of the grooved plug,
The processing pitch P (mm) of the pressing tool is
0.2 ≦ P ≦ 0.4
The apparatus for manufacturing an internally grooved tube according to claim 17, which is set to fall within the range of
Drawing means for drawing an internally grooved pipe that has been processed on the downstream side in the tube axis direction of the groove processing means, and processing that occurs in the pipe axis direction along with the drawing of the raw pipe on the upstream side in the tube axis direction from the drawing means The manufacturing apparatus of the inner surface grooved pipe according to claim 13, further comprising processing related data detecting means for detecting processing related data relating to the load.
The machining-related data detection means is constituted by at least one of a grooving load measuring means for measuring the machining load in the grooving means and a reduced diameter processing load measuring means for measuring the machining load in the reduced diameter means. The apparatus for manufacturing an internally grooved tube according to claim 20.
An intermediate drawing means for drawing a raw pipe between the diameter reducing means and the groove processing means;
The manufacturing apparatus for an internally grooved tube according to claim 20 or 21, wherein the processing related data detection means is configured by load related data detection means for detecting load related data related to a drawing load of a motor of the intermediate drawing means.
23. The apparatus for manufacturing an internally grooved tube according to claim 20, further comprising a disconnection determination unit that determines that a disconnection has occurred based on the processing related data detected by the processing related data detection unit.
Using the inner surface grooved pipe manufacturing apparatus according to claim 23,
A method for manufacturing an internally grooved tube, wherein the disconnection determination means determines that a disconnection has occurred based on the processing related data detected by the processing related data detection means, and stops processing.