JP6909054B2 - Manufacturing method and manufacturing equipment for multiple twisted pipes with inner spiral groove - Google Patents

Description

The present invention relates to a method and an apparatus for manufacturing a multi-twisted tube with an inner spiral groove used for a heat transfer tube or the like of a heat exchanger.

Conventionally, there has been known a tube heat exchanger that exchanges heat between an inner flow path and a plurality of outer flow paths arranged around the inner flow path in the pipe, and between a refrigerant flowing inside and outside.
Patent Document 1 discloses a double-tube heat exchanger in which heat exchange performance is improved while suppressing an increase in cost in a heat pump type heat source machine.

Japanese Unexamined Patent Publication No. 2016-99075

One of the problems of the double-tube heat exchanger is to satisfy the demand for suppressing the cost increase and improving the heat exchange performance. It is possible to improve the heat exchange performance by increasing the length of the double-tube heat exchanger, but on the other hand, there is a problem that the heat exchanger becomes larger and the cost increases due to the increase in material cost. be.

The present invention has been made in view of such circumstances, and a structure in which a plurality of inner spiral grooved tubes having high dimensional accuracy of groove shape and twist angle in the longitudinal direction are assembled can be obtained, and production with excellent heat exchange efficiency can be obtained. It is an object of the present invention to provide a method and an apparatus for manufacturing a multi-twisted tube with an inner spiral groove having excellent properties.

In the method for manufacturing a multiple twisted pipe with an inner spiral groove according to the present invention, a plurality of raw pipes having different diameters in which a plurality of grooves along the length direction are formed at intervals in the circumferential direction are prepared on the inner surface and have a large diameter. A small-diameter pipe is inserted into the pipe to form a composite pipe, and the composite pipe is wound around the unwinding side capstan from the direction of its introduction side tangent, and the composite pipe is drawn along the lead-out side tangent. unwinding Te, by rotating the unwinding side capstan axis as an axis of the discharge side tangent line, extending from the unwinding side capstan of the tangent line while rotating the composite mother tube Ri said Jikukai It is provided with a raw tube unwinding step of unwinding in a direction and a twisting and pulling step of passing the unwound composite raw tube through a drawing die to apply a twist while reducing the diameter to form a multiple twisted tube with an inner spiral groove. It is a feature.

In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, a bare tube having a straight groove on the inner surface can be used as a groove along the length direction.
In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, a bare tube having an inner spiral groove can be used as a groove along the length direction.
In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, the diameter reduction ratio by the drawing die can be set to 5 to 40%.

Manufacturing method of the inner surface helical grooved multi torsion tube according to the present invention, the composite blank tube into the drawing die side from a position between the take-out-out side capstan start winding the composite element tube to the winding-out-out side capstan by shifting in a direction parallel to the rotation axis of the feed start position the take-out-out side capstan and between the winding-out-out side capstan and the drawing die to a twisting processing area of the composite base pipe Can be done.
In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, when the composite element tube is passed through the drawing die and the composite element tube is twisted to reduce the diameter, forward tension and rear tension are applied to the composite element tube. be able to.
In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, the multi-twisted tube with an inner spiral groove that has passed through the drawing die can be wound around a capstan on the drawing side.
In the method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention, the multi-twisted tube with an inner spiral groove unwound from the drawing-side capstan can be shaped with a second drawing die.

The apparatus for manufacturing a multi-twisted pipe with an inner spiral groove according to the present invention is made of a plurality of metal pipes having different diameters in which a plurality of grooves along the length direction are formed on the inner surface at intervals in the circumferential direction. A disk-shaped unwinding side that allows a composite base tube with a small diameter base pipe inserted into a large-diameter base pipe to be freely wound from the direction of the introduction side tangent, and to be freely unwound along the lead-out side tangent line parallel to the introduction side tangent. A drawing die that reduces the diameter and twists through the capstan, the rotating means for rotating the unwinding side capstan around the lead-out side tangent, and the composite raw pipe unwound from the unwinding side capstan. It is characterized by having.

Apparatus for producing the inner surface helical grooved multi torsion tube according to the present invention, the composite blank tube into the drawing die side from a position between the take-out-out side capstan start winding the composite element tube to the winding-out-out side capstan the start feed position is shifted in a direction parallel to the rotation axis of the take-out-out side capstan, twisting processing region of the base pipe between the unwinding position of the out side capstan-out the winding said drawing die It is characterized by being said.
The apparatus for manufacturing a multi-twisted pipe with an inner spiral groove according to the present invention is provided with a front tension applying means for applying a front tension to the composite raw pipe on the front stage side of the unwinding side capstan, and is provided on the rear stage side of the drawing die. Is provided with a rear tension applying means for applying a rear tension to the multi-twisted pipe with an inner spiral groove.
The apparatus for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention is characterized in that a pull-out side capstan for winding and unwinding the multi-twisted tube with an inner spiral groove is provided on the rear stage side of the drawing die.
The apparatus for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention is characterized in that a second drawing die for shaping the multi-twisted tube with an inner spiral groove is provided on the rear stage side of the capstan on the drawing side. ..

According to the present invention, an unprecedented inner spiral groove having a structure in which a plurality of metal inner spiral grooved tubes in which a plurality of spiral grooves along the length direction are formed on the inner surface at intervals in the circumferential direction are combined. Multiple twisted tubes can be provided.

The cross-sectional view which shows the 1st Embodiment of the multi-twisted tube with an inner spiral groove obtained by the manufacturing apparatus which concerns on this invention. The development view which cut open a part of the multiple twisted pipes with an inner spiral groove of the same embodiment. The side view which shows the whole structure of the manufacturing apparatus. The plan view which shows the whole structure of the manufacturing apparatus. A plan view showing a state in which a raw pipe is wound around a capstan on the unwinding side of the manufacturing apparatus and unwound. An example of a raw pipe supplied to the manufacturing equipment is shown, where (a) is a cross-sectional view and (b) is a cross-sectional view. A cross-sectional view showing a state in which a small-diameter raw pipe is inserted inside a large-diameter raw pipe to form a composite raw pipe. FIG. 5 is a cross-sectional view showing a second embodiment of a multi-twisted pipe with an inner spiral groove in which three types of pipes with an inner spiral groove having different diameters are compositely integrated. FIG. 5 is a cross-sectional view showing a third embodiment of a multi-twisted pipe with an inner spiral groove having a structure in which three small-diameter inner spiral grooved pipes are combined and integrated inside a large-diameter inner spiral grooved pipe. FIG. 3 is a perspective view showing three small-diameter inner spiral grooved pipes extracted from the multiple twisted pipe with inner spiral groove of the third embodiment. A specific example of the multiple twisted pipe with an inner spiral groove manufactured in the examples is shown, (a) is a cross-sectional view, and (b) is a partially enlarged view thereof.

Hereinafter, an embodiment of an apparatus for manufacturing a multi-twisted tube with an inner spiral groove and a method for manufacturing a multi-twisted tube with an inner spiral groove according to the present invention will be described with reference to the drawings.
In the device A for manufacturing a multi-twisted tube with an inner spiral groove (see FIGS. 3 to 4) of the present embodiment, a plurality of straight grooves along the length direction are formed on the inner surface at intervals in the circumferential direction. A composite base tube F in which a plurality of different base pipes (see FIGS. 6 and 7), for example, two pipes (base pipes 1 and 8) are combined is applied.
In the manufacturing apparatus A, for example, the raw pipe 8 is inserted into the raw pipe 1 to form a composite raw pipe F, a constant twist is generated in the composite raw pipe F, and a small-diameter inner spiral having a spiral groove 2a on the inner surface shown in FIG. This is an apparatus for manufacturing a multi-twisted pipe 4 with an inner spiral groove, which integrates a grooved pipe 2 and a large-diameter inner spiral grooved pipe 3 having a spiral groove 3a on the inner surface.

In the present embodiment, FIG. 3 shows a side surface of the overall structure of the manufacturing apparatus A, and FIG. 4 shows a plane of the overall structure of the manufacturing apparatus A.
As shown in FIG. 7, the manufacturing apparatus A has a composite raw pipe F in which a small diameter raw pipe 8 having an equivalent structure is inserted into a raw pipe 1 having a linear groove (see FIG. 7) 1a formed on the inner surface thereof. 3. As shown in FIG. 4, the unwinding side capstan 5 held in a coiled state and the composite raw tube F unwound from the unwinding side capstan 5 are rotated together with the unwinding side capstan 5. The rotating means 6 is provided. Further, the manufacturing apparatus A includes a drawing die 7 through which the composite element pipe F sent out from the unwinding side capstan 5 is passed, and a multi-twisted pipe 4 with an inner spiral groove that has been twisted and drawn through the drawing die 7. It is equipped with a pull-out side capstan 9 that sends out while winding.

As shown in FIG. 6, for example, in the raw pipe 1, a plurality of straight grooves 1a are formed on the inner surface of the pipe body 1A along the length direction, and fins 1b are formed between the straight grooves 1a and 1a adjacent to each other in the inner peripheral direction. ing. The raw pipe 1 is made of aluminum or an aluminum alloy pipe, and is formed to have an outer diameter of, for example, about 3 to 20 mm, more specifically, about 3 to 12 mm.
A raw tube 8 having an outer diameter slightly smaller than the inner diameter of the raw tube 1 is inserted into the raw tube 1 along the length direction of the raw tube 1 to form a composite raw tube F. The raw pipe 8 has the same structure as the raw pipe 1 and is formed to have a slightly smaller outer diameter. It is made of aluminum or an aluminum alloy pipe, and has an outer diameter of, for example, about 3 to 20 mm, more specifically, about 3 to 12 mm. It is formed to have an outer diameter that can be inserted into the raw tube 1. In the raw pipe 8, as shown in FIG. 8, a plurality of straight grooves 8a are formed on the inner surface of the pipe body 8A along the length direction, and fins 8b are formed between the straight grooves 8a and 8a adjacent to each other in the inner peripheral direction. The structure is also the same as that of the raw pipe 1.

In this embodiment, the raw pipes 1 and 8 are made of aluminum or an aluminum alloy, but the raw pipes 1 and 8 may be made of a copper-based alloy or an iron-based alloy such as stainless steel. In this embodiment, the raw pipes 1 and 8 made of aluminum or an aluminum alloy will be described as an example, but the multiple twisted pipe with an inner spiral groove, which is the object of the present invention, can be applied as long as it is a material that can be pulled out by a drawing die. Therefore, it goes without saying that the present invention may be carried out using a raw tube made of another alloy such as a copper-based alloy or an iron-based alloy.
The outer raw pipe 1 and the inner raw pipe 8 do not have to be made of the same material, and the raw pipe 1 may be made of a copper alloy, the raw pipe 8 may be made of an aluminum alloy, or the like. Further, even if the same aluminum alloy is used, the raw pipe 1 and the raw pipe 8 can be made of aluminum alloys having different compositions. Further, although the raw pipe 1 and the raw pipe 8 are displayed as raw pipes having similar shapes in this example, the widths of the straight grooves 1a and 8a formed on their inner surfaces and the widths and heights of the fins 1b and 8b are formed. , The formation pitch and the like may be different between the inner raw pipe 8 and the outer raw pipe 1.

As shown in FIG. 4, the unwinding side capstan 5 is rotatably and horizontally rotatably around the bearing portion 12 attached to the upper end portion of the support column members 10 and 11 made of steel materials erected in the front-rear direction apart from each other. It is supported by the supported hollow shaft portion 13. The unwinding side capstan 5, the die 7, and the pulling out side capstan 9 are sequentially arranged along the extension line in the length direction of the hollow shaft portion 13, and the composite raw pipe F is the hollow shaft portion 13, the unwinding side. The capstan 5, the drawing die 7, and the drawing side capstan 9 are moved and processed in this order. Therefore, in the following description, the upstream side will be appropriately referred to as the front stage side and the downstream side will be referred to as the rear stage side along the moving direction of the composite pipe F.

The hollow shaft portion 13 is horizontally provided supported by bearing members 10a and 11a provided at the upper end portion of the strut member 10 and the upper end portion of the strut member 11, respectively, and one end 13a thereof is upstream from the upper end portion of the strut member 10. It is supported horizontally and rotatably around the axis by projecting the other end 13b from the upper end of the support column member 11 to the outside on the downstream side. A pair of first support frames 15 extending diagonally adjacent to the hollow shaft portion 13 are provided on the other end side of the hollow shaft portion 13, and the unwinding side capstan 5 is supported by the tip portion 15a. There is.
A second support frame 16 is provided on the other end side of the hollow shaft portion 13 so as to extend diagonally with respect to the hollow shaft portion 13, and the extension frame 17 extending to the tip end side of the second support frame 16 A weight body 18 is attached. The first support frame 15 and the second support frame 16 are connected to the other end 13b of the hollow shaft portion 13 so as to be arranged in a V shape, and are connected to the first support frame 15 by rotation of the hollow shaft portion 13 around the axis. The second support frame 16 is rotated while being supported in a V shape.

The central portion of the disc portion 5a of the unwinding side capstan 5 is rotatably supported by the first support frame 15 and its tip portion 15a. Further, the unwinding side capstan 5 is supported by the first support frame 15 so that the extension line of the central axis of the hollow shaft portion 13 approximates the tangent line of the outer peripheral edge of the unwinding side capstan 5. Therefore, when the unwinding side capstan 5 rotates with the rotation of the hollow shaft portion 13, the unwinding side capstan 5 rotates so as to orbit around the extension line of the central axis of the hollow shaft portion 13. Similarly, as the hollow shaft portion 13 rotates, the weight body 18 also rotates so as to orbit around the extension line of the central shaft of the hollow shaft portion 13.
The unwinding side capstan 5 is configured so that the composite raw tube F can be wound along the outer peripheral edge of the disk portion 5a.

For example, when the hollow shaft portion 13 is rotated so that the unwinding side capstan 5 is in the lowest position as shown in FIG. 4, the hollow shaft portion 13 is slightly above the uppermost portion of the unwinding side capstan 5. An extension of the central axis passes. Alternatively, when the hollow shaft portion 13 is rotated so that the unwinding side capstan 5 is in the uppermost position, the extension line of the central shaft portion of the central shaft portion 13 is slightly below the lowermost portion of the unwinding side capstan 5. Passes.
An inlet portion 13c having a size capable of inserting the composite base pipe F is formed in the opening on the one end 13a side of the hollow shaft portion 13, and the previous composite base pipe is formed in the opening on the other end 13b side of the hollow shaft portion 13. An outlet portion 13d from which F can be pulled out is formed.

Therefore, the composite raw pipe F that has passed through the inside of the hollow shaft portion 13 can be introduced along the tangent line of the outer circumference of the unwinding side capstan 5 and wound around the outer circumference of the unwinding side capstan 5. , For example, a composite element tube F wound around the outer circumference of the unwinding side capstan 5 for one round can be unwound from the outer circumference of the unwinding side capstan 5 and led out to the drawing die 7.
FIG. 6 briefly shows an example of the winding state and the unwinding state of the composite raw tube F with respect to the unwinding side capstan 5. In FIG. 5, C shows the axis of the composite element tube F wound on the unwinding side capstan 5, and C1 indicates the axis of the composite element tube F unwound from the unwinding side capstan 5. There is.

The first support frame 15 and the second support frame 16 extend in a V shape on the other end side of the hollow shaft portion 13, and the unwinding side capstan 5 and the weight body 18 are attached to their tip ends. However, the weight and mounting position of the weight body 18 and the unwinding side capstan 5 are set so that the weight balance can be balanced when they rotate. That is, when the weight body 18 and the unwinding side capstan 5 are swiveled by the rotation of the hollow shaft portion 13, the unwinding is performed so that the balance of the rotational moments of both is balanced and the vibration accompanying the rotation of both is as small as possible. The weights and mounting positions of the side capstan 5 and the weight 18 are adjusted.

A support plate 20 is erected between the upper part of the support plate member 10 and the upper part of the support plate member 11, the drive motor 21 is attached to the support plate 20, and the power transmission device 22 such as an endless belt is connected to the output shaft 21a of the drive motor 21. Has been done. The power transmission device 22 is connected to one end side of the hollow shaft portion 13 located above the power transmission device 22, and the hollow shaft portion 13 can be rotationally driven by the rotation of the output shaft 21a of the drive motor 21.
The drive motor 21, the power transmission device 22, and the hollow shaft portion 13 rotate the unwinding side capstan 5 and the weight body 18 integrally, and the drive motor 21, the power transmission device 22, and the hollow shaft portion 13 wind the capstan 5 and the weight body 18. A rotating means 6 for rotationally driving the output side capstan 5 is configured.

The unwinding side capstan 5 is provided on the downstream side of the outlet portion 13d of the hollow shaft portion 13, and the drawing die 7 is provided on the downstream side of the hollow shaft portion 13 while being supported by the support column member 23. As shown in FIG. 4, the drawing die 7 is installed so that the die hole is arranged at the same height as the outlet portion 13d of the hollow shaft portion 13 and is located between the outlet portion 13d of the hollow shaft portion 13 and the drawing die 7. The path line is aligned with the upper end of the outer peripheral edge of the unwinding side capstan 5 located. In this example, the drawing die 7 is attached to the upper end of the support column member 23 via a hollow support base 24. Further, above the support frame 25, a tank 26 and a flexible supply pipe 27 for supplying lubricating oil to the die holes of the drawing die 7 are installed.

The drawing die 7 has a die hole through which the composite raw pipe F is inserted, and performs empty drawing to reduce the outer diameter of the composite raw pipe F. The diameter reduction ratio of the drawing die 7 is set to about 5 to 40% in the case of the raw tubes 1 and 8 made of aluminum or an aluminum alloy. If the diameter reduction ratio is too small, the effect of pulling out is poor and it is difficult to obtain a large twist angle. Therefore, it is preferably 5% or more. On the other hand, if the diameter reduction ratio becomes too large, the composite raw tube F is likely to break at the processing limit, so it is preferably 40% or less.
Further, when the composite raw pipe F passes through the die hole, the unwinding side capstan 5 is rotated, so that the composite raw pipe F is reduced in diameter by the die hole of the drawing die 7 and at the same time twisted. Therefore, the raw pipes 1 and 8 constituting the composite raw pipe F are twisted and processed into the multiple twisted pipe 4 with an inner spiral groove shown in FIG.

The pull-out side capstan 9 is provided on the downstream side of the pull-out die 7 by being supported by the support support member 23, and the pull-out side capstan 9 is installed vertically via the horizontal shaft 28 supported by the support support member 23 and is rotatable. It is supported. The uppermost portion of the pull-out side capstan 9 is installed at the same height as the position of the die hole of the pull-out die 7, and the multiple twisted pipe 4 with an inner spiral groove machined by the pull-out die 7 is wound along the outer peripheral surface thereof. It has become.
The output shaft 25a of the drive motor 25 for rotational drive is installed so as to be directly connected to the horizontal shaft 28 on the side opposite to the side where the pull-out side capstan 9 is attached in the support column member 23, and the pull-out side capstan 9 is installed by the drive motor 25. Is configured to be rotationally driven.

"Production method"
Next, a method of manufacturing the multiple twisted pipe 4 with an inner spiral groove will be described using the manufacturing apparatus A configured as described above.
As shown in FIGS. 6 and 7, a large-diameter raw pipe 1 in which a plurality of straight grooves 1a along the length direction are formed in advance by extrusion on the inner surface at intervals in the circumferential direction, and a length on the inner surface. A small-diameter raw pipe 8 in which a plurality of straight grooves 8a along the direction are formed at intervals in the circumferential direction is produced (raw pipe extrusion step).
Next, a composite raw pipe F is formed by inserting a raw pipe 8 having a small outer diameter inside the raw pipe 1 having a large outer diameter as shown in FIG. (Composite tube manufacturing process)
In order to supply the composite base pipe F to the manufacturing apparatus A shown in FIGS. 3 to 4, the tip end side of the composite base pipe F is inserted from the inlet portion 13c of the hollow shaft portion 13 into the hollow shaft portion 13, and the hollow shaft portion is inserted. The composite raw pipe F is pulled out from the outlet portion 13d of 13, and is wound around the outer circumference of the unwinding side capstan 5 for one round as shown in FIG. This composite raw tube F is horizontally unwound from the unwinding side capstan 5 in the tangential direction, inserted into the die hole of the drawing die 7, and the composite raw tube F passed through the die hole of the drawing die 7 is passed through the drawing side capstan. Wrap it around 9 for one round or more, and pull out the composite raw pipe F to the downstream side of the capstan 9 on the pull-out side. These operations are preparatory work before the start of production of the multi-twisted tube with an inner spiral groove.

After this preparatory work, a tubular restraint 31 is placed on the front end side and the rear end side of the composite raw tube F, respectively, as shown in FIG. 31a is screwed to restrain the front end side and the rear end side of the composite raw tube F. Next, as shown in FIG. 4, a spring-scale tension adjuster 32 provided with a coil spring for tension adjustment is connected to the restraint 31 on the front end side of the composite base pipe F, and the tension adjuster 32 on the rear end side of the composite base pipe F is connected. A spring-scale tension adjuster 33 provided with a coil spring for tension adjustment is connected to the restraint 31.

From this state, the processing of the composite raw tube F is started. Along with the start of processing, the composite raw tube F is sequentially moved at a constant speed to pass through the hollow shaft portion 13 and wound around the unwinding side capstan 5 (unwinding step). The pulling force for passing the composite raw pipe F through the pulling die 7 is given by the rotational force of the pulling side capstan 9 rotated by the drive motor 25.
The drawing die 7 is passed through the composite raw tube F unwound from the unwinding side capstan 5, wound around the pulling out side capstan 9, and unwound from the unwinding side capstan 9 at a constant speed. At the same time as starting these operations, the hollow shaft portion 13 is rotated at a predetermined speed by the drive motor 21, and the unwinding side capstan 5 and the weight body 18 are rotationally driven (twisting and pulling step).

Further, while monitoring the tension of the tension adjusting tools 32 and 33, the rear tension when the composite raw pipe F is wound around the unwinding side capstan 5 is adjusted to be constant.
Further, the forward tension when the composite raw pipe F is pulled out from the pull-out side capstan 9 is adjusted to be constant.
In order to stably apply the forward tension, a tensioning device such as a take-up roller or a winch device is arranged on the downstream side of the tension adjusting tool 32, and the tension adjusting tool 32 is adjusted so that it can be towed at a constant speed. Is preferable. Further, in order to stably apply the rear tension, an unwinding device such as an unwinding roller is arranged on the upstream side of the tension adjusting tool 33, and the tension adjusting tool 33 is adjusted so that the tension adjusting tool 33 can be unwound at a constant speed. Is preferable.
Alternatively, the tension adjusters 32 and 33 are abbreviated, and a winding roller and a winding roller are arranged at these positions, and a brake mechanism and a speed adjusting mechanism are built in these rollers on the downstream side of the drawing die 7. Mass production is carried out by applying a desired forward tension to the tip end side of the composite body tube F and applying a desired rearward tension to the rear end side of the composite body tube F on the upstream side of the drawing die 7. Above is preferred.

The die of the drawing die 7 from the unwinding side capstan 5 while applying an appropriate rear tension to the composite body pipe F on the downstream side centering on the drawing die 7 and applying an appropriate rear tension to the composite body pipe F on the upstream side. At the same time that the composite raw pipe F is passed through the hole, the unwinding side capstan 5 is rotated so that the composite raw pipe F passing through the die hole of the drawing die is simultaneously pulled out and twisted.
Usually, when only a twisting force is applied to thin-walled raw tubes 1 and 8 made of aluminum or an aluminum alloy having an outer diameter of about 3 to 20 mm or about 3 to 12 mm, they easily buckle or break. In this manufacturing apparatus A, a pulling force is applied at the same time as the action of the twisting force to pull out while suppressing breakage due to twisting. Even if the raw tube F is used, twisting can be added without breaking it.

In this case, a shear stress acts on the composite base tube F in the circumferential tangential direction due to twisting to give a torsion angle (lead angle), but buckling occurs when the shear force exceeds the buckling stress. However, since the shear stress can be reduced by the tensile stress in the longitudinal direction of the raw pipe bundle due to the drawing process, the occurrence of buckling of the composite raw pipe F can be suppressed. Therefore, even if a large twist angle of about 5 ° to 80 ° is applied to the composite raw pipe F having the above-mentioned size, the composite raw pipe F can be twisted without buckling or breaking.

As shown in FIG. 3, a region having a length L between the top position of the unwinding side capstan 5 and the outlet portion of the drawing die 7 is defined as a twisting region of the composite raw pipe F. In the manufacturing apparatus A, the length L of this twisting region is made as short as possible, so even if a large twisting angle is given to the composite raw pipe F, the raw pipes 1 and 8 are not broken and are 5 ° to 5 °. Twisting can be applied up to about 80 °.

As shown in FIG. 5, the composite raw tube F is wound around the unwinding side capstan 5 for one round, so that the axial center is slightly deviated from the unwinding side axis C along the outer circumference of the unwinding side capstan 5. It is sent out along C1.
When the composite element tube F passes through the die hole of the drawing die 7, the center of the composite element tube F and the center of the die hole should be aligned so that extra stress does not act on the composite element tube F. , The positional relationship of the hollow shaft portion 13 and the first It is preferable to match the positional relationship of the support frame 15 with the positional relationship of the unwinding side capstan 5.
By aligning the center of the composite raw pipe F with the center of the die hole, a large twist is added to the composite raw pipe F passing through the die hole 7, and the composite raw pipe is processed with a large twist angle. It can be twisted without breaking F.

The center of rotation for rotating the unwinding side capstan 5 coincides with the center of the hollow shaft portion 13, but this center of rotation is aligned with the center of the die hole of the drawing die 7 and is aligned with the center of the die. It is necessary to move the center of the composite body tube F. Therefore, the composite raw tube F before being wound around the unwinding side capstan 5 rotates at a position slightly deviated from the axial center. Therefore, the composite raw tube F before being wound around the unwinding side capstan 5 is eccentrically rotated inside the hollow shaft portion 13, but the inner diameter of the hollow shaft portion 13 is a value that only absorbs this eccentric rotation. Since it is set to, there is no problem in the rotation of the composite raw tube F.

As a result of being able to give a large twist to the composite raw tube F passing through the drawing die 7 by performing the twist pulling process described above, the raw pipes 1 and 8 are twisted in a spiral shape, respectively, and have a spiral groove 2a on the inner surface. It is possible to manufacture a multi-twisted tube 4 with an inner spiral groove having a structure shown in FIG. 1 in which an inner spiral grooved tube 2 and an inner spiral grooved tube 3 having a spiral groove 3a on the inner surface are integrated.
In the multiple twisted pipe 4 with an inner spiral groove, the inner spiral grooved pipe 2 and the inner spiral grooved pipe 3 are spirally processed at a predetermined twist period (twisting pitch). Therefore, the twist period of the inner spiral groove 2a formed on the inner surface of the inner spiral grooved tube 2 and the inner spiral groove 3a formed on the inner surface of the inner spiral grooved tube 3 are formed to be substantially the same.

FIG. 2 shows an example of the internal structure of the inner spiral grooved tube 3 in which the inner spiral groove 3a is formed. An inner spiral groove 3a adjacent to the inner peripheral direction is formed in the inner peripheral portion of the inner spiral grooved tube 3, and a spiral fin 3b is formed between them.
The twist angle θ of the inner spiral groove 3a and the spiral fin 3b in this example can be manufactured to, for example, about 5 ° to 80 ° depending on the rotation speed of the unwinding side capstan 5.
When the peripheral wall of the inner spiral grooved pipe 3 having the structure shown in FIG. 2 is cut open and developed in a plane, the length of one cycle of the inner spiral groove 3a or the spiral fin 3b is relative to the inner peripheral length a of the pipe. In the case of b, the twist angle θ is defined as indicated by one apex angle of a right triangle having a and b as two sides.
As an example, in the case of an aluminum alloy inner spiral grooved tube 3 having an outer diameter of 8.5 mm, the bottom wall thickness W1: 0.58 mm, fin height: 0.28 mm, number of threads: 50, leads shown in FIG. In the case of an aluminum alloy inner spiral grooved tube 2 having an outer diameter of 6.5 mm, which can be formed at an angle of 20 °, the bottom wall thickness W2: 0.35 mm, fin height: 0.16 mm, number of threads: 50 pieces can be formed with a lead angle of 17 °.

In the multi-twisted tube 4 with an inner spiral groove having the structure shown in FIG. 1, the spiral fins 3b on the inner surface side of the inner spiral grooved tube 3 have their tips bite into the outer peripheral surface of the inner spiral grooved tube 2 having a small diameter. The inner spiral grooved pipe 2 and the inner spiral grooved pipe 3 are integrated. This is because, as shown in FIG. 7, a small-diameter raw tube 8 is inserted inside a large-diameter raw tube 1, and the entire raw tube 8 is pulled out through a drawing die 7 while being rotated and twisted while reducing the diameter. This is a result of plastic deformation while the linear fins 1b on the inner surface side of the raw pipe are spirally processed and bite into the outer peripheral surface of the small raw pipe 8 when the diameter of the large raw pipe 1 is reduced. Therefore, the tip end portion of the spiral fin 3b is a bite portion that is bitten into the outer peripheral surface of the inner spiral grooved tube 2.
According to the configuration described above, the inner surface spiral grooved tube 2 and the inner surface spiral grooved tube 3 are surrounded by the outer peripheral surface of the inner surface spiral grooved tube 2 and the spiral groove 3a and the spiral fin 3b of the inner surface spiral grooved tube 3. A plurality of flow paths are formed. Therefore, in the multiple twisted pipe 4 with an inner spiral groove, a first flow path R1 is formed on the inner side of the inner spiral grooved pipe 2, and between the inner spiral grooved pipe 2 and the inner spiral grooved pipe 3. A plurality of second flow paths R2 are formed in the water. As shown in the cross section shown in FIG. 1, the second flow path R2 is an aggregate of a plurality of small flow paths. In order to increase the cross-sectional area of the second flow path R2, an inner spiral grooved tube is used. It can be dealt with by setting the height of the spiral fin 3b of No. 3 to be larger than the structure of FIG. 1 and reducing the number of threads of the spiral fin 3b.

In the multiple twisted pipe 4 with an inner spiral groove, since the inner spiral grooved pipe 3 is arranged on the outside of the inner spiral grooved pipe 2, the inner spiral groove is formed from the lead angle of the spiral groove 2a of the inner spiral grooved pipe 2. The lead angle of the spiral groove 3a of the attached pipe 3 is formed to be slightly large. In other words, the lead angle of the spiral fin 3b of the inner spiral grooved tube 3 is formed to be slightly larger than the lead angle of the spiral fin 2b of the inner spiral grooved tube 2.
The magnitude relationship between the lead angle of the spiral groove 2a of the inner spiral grooved tube 2 and the lead angle of the spiral groove 3a of the inner spiral grooved tube 3 will be shown in Examples described later as an example.

Further, according to the above-mentioned manufacturing method, the twist angle of the spiral groove 2a of the inner spiral grooved tube 2 made of aluminum or an aluminum alloy and the twist angle of the spiral groove 3a of the inner spiral grooved tube 3 are 5 ° to 40 °. It can be manufactured to the extent. The pitch of the inner spiral grooved pipes 2 and 3 is determined by the relative ratio between the pulling speed when the composite raw pipe F passes through the pulling die 7 and the rotation speed of the unwinding side capstan 5. Therefore, if the pull-out speed of the composite raw tube F and the rotation speed of the unwinding side capstan 5 are kept constant, the multi-twisted tube 4 with an inner spiral groove having a constant twist angle and a constant pitch along the length direction. Can be obtained.
Further, if the relationship between the pull-out speed and the rotation speed of the composite raw tube F is periodically changed, it is possible to obtain a multiple twisted tube 4 with an inner spiral groove whose pitch and twist angle change periodically in the length direction. ..

In the case of the multi-twisted pipe 4 with an inner spiral groove having the configuration shown in FIG. 1 manufactured as described above, in addition to the first flow path R1 inside the inner spiral grooved pipe 2, the inner spiral grooved pipe 2 When a refrigerant or a heat medium having a different temperature is passed through the second flow path R2 between the pipe 3 and the inner spiral grooved pipe 3, heat is generated between the refrigerants or the heat mediums having different temperatures, or between the refrigerant and the heat medium. Can be exchanged.
In this case, the refrigerant or heat medium efficiently exchanges heat between the refrigerant or heat medium and the inner spiral grooved pipes 2 and 3 due to the presence of the inner spiral grooves 2a and 3a.
Therefore, for example, if the multiple twisted tube 4 with an inner spiral groove of the present embodiment is applied to a heat transfer tube that connects an automobile capacitor and an evaporator, a heat transfer tube structure having an efficient heat exchange function can be realized. Normally, two heat transfer tubes are required to connect the capacitor for automobiles and the evaporator, but in the case of the multiple twisted tube 4 with an inner spiral groove in FIG. 1, the first flow path R1 and the second flow path R2 are used. Since it is provided, both can be connected by one multi-twisted pipe 4 with an inner spiral groove.
In this case, in order to equalize the flow rates of the refrigerant or heat medium flowing back and forth between the condenser and the evaporator, it is sufficient to make the flow path cross-sectional areas of the first flow path R1 and the second flow path R2 equal, which is large. The height and width of the spiral fins 3b of the inner spiral grooved tube 3 on the diameter side may be increased to reduce the number of threads.

In the manufacturing apparatus A of the present embodiment, a pre-shaping die for shaping to improve the roundness of the composite raw tube F may be provided on the front stage side of the hollow shaft portion 13.
Further, in the manufacturing apparatus A of the present embodiment, the raw pipes 1 and 8 constituting the composite raw pipe F are previously set as inner spiral grooved pipes, and these inner spiral grooved pipes are combined and passed through the drawing die 7. The diameter and twist may be applied at the same time to form a multiple twisted tube with an inner spiral groove.

The manufacturing apparatus A of the present embodiment can process the composite raw pipe F, but can also twist one raw pipe 1 or one raw pipe 8. For example, by simultaneously applying the diameter reduction processing and the twisting processing to one raw pipe 1 by using the manufacturing apparatus A, the inner surface spiral grooved pipe 2 provided with the inner surface spiral groove 2a can be obtained independently.

Since the manufacturing apparatus A can manufacture one inner spiral grooved pipe, two inner spiral grooved pipes having different diameters are combined to form a composite raw pipe, and the drawing die 7 is further formed as described above. A multi-twisted tube with an inner spiral groove may be manufactured by passing it through and performing a twist-pulling process.
A multi-twisted tube with an inner spiral groove with a twist angle of about 5 ° to 40 ° can be manufactured by processing while precisely applying drawing and twisting when passing through the die hole of the drawing die 7. Depending on the composition of the aluminum alloy constituting the material, it is considered that the material has a low elongation and a high risk of breaking. In such a case, it is possible to gradually process the target large twist angle by dividing it into two or three times instead of processing it by one twisting and pulling process. By dividing into a plurality of times of processing in this way, it is possible to process the multiple twisted pipe 4 with an inner spiral groove having a large twist angle while reducing the risk of breakage.

Further, even if one large-diameter raw pipe is subjected to a certain amount of torsional drawing to form an inner spiral grooved pipe, and then combined with a small-diameter raw pipe having a straight groove, a second torsional drawing is performed. good.
In this case, if a lead angle of 10 ° is given in the first twist-drawing process and a lead angle of 10 ° is further given in the second twist-pulling process, the inner surface on the large diameter side is subjected to the twist-pulling process. The lead angle of the spiral fin (spiral groove) formed in the spiral grooved pipe is 20 °, and the lead angle of the spiral fin (spiral groove) formed in the inner spiral grooved pipe on the small diameter side is 10 °. Multiple twisted pipes can be manufactured.
In addition, if one small-diameter raw pipe is subjected to a certain amount of twist-pulling processing to form an inner spiral grooved pipe, and then combined with a large-diameter raw pipe having a straight groove, a second twist-pulling process is performed. , The lead angle of the spiral fin (spiral groove) formed in the inner spiral grooved pipe on the small diameter side is 20 °, and the lead angle of the spiral fin (spiral groove) formed in the inner spiral grooved pipe on the large diameter side is 10. A multi-twisted tube with an inner spiral groove can be manufactured.

In this way, if a multi-twisted pipe with an inner spiral groove is manufactured while adjusting the state of the groove of the raw pipe using the above-mentioned manufacturing apparatus A, the lead angle and the small diameter side of the spiral fin (spiral groove) on the large diameter side are produced. It is possible to manufacture a multi-twisted tube with an inner spiral groove having a structure in which the magnitude relationship of the lead angle of the spiral fin (spiral groove) is freely adjusted.
Further, a drawing die for shaping may be further provided on the downstream side of the drawing-side capstan 9, and finish drawing may be performed to increase the roundness of the multi-twisted pipe 4 with an inner spiral groove.
In order to provide a drawing die for finish drawing, a support member having the same shape as the support member 23 shown in FIG. 3 is provided on the downstream side of the support member 23, and a support frame having the same shape as the support frame 25 is separately provided above the support frame member 23. It is advisable to provide a drawing die for finish molding on the support frame.
By passing the multi-twisted tube with inner spiral groove after passing through the capstan 9 on the drawing side through a drawing die for finish molding, the roundness of the multi-twisted tube with inner spiral groove finally obtained is improved, and the shape of the multi-twisted tube is improved. A well-ordered multi-twisted tube with an internal spiral groove can be provided.

"Second embodiment"
In the above embodiment, the raw pipes 1 and 8 are combined and integrated, and twisting and drawing are performed to obtain a multiple twisted pipe 4 with an inner spiral groove. An arbitrary number can be selected. For example, three raw pipes having different diameters are inserted to form a triple pipe, and the triple pipe is drawn out while being twisted by the manufacturing apparatus A, as shown in FIG. A multi-twisted tube 34 with an inner spiral groove having a triple tube structure can be manufactured.
The multiple twisted pipe 34 with an inner spiral groove shown in FIG. 8 is twisted by combining one raw pipe having a larger diameter on the outside of the multiple twisted pipe 4 with an inner spiral groove having the structure shown in FIG. It is a structure manufactured by performing a drawing process.

In the structure shown in FIG. 8, the inner spiral grooved tube 35 having the largest diameter has an inner spiral groove 35a and a spiral fin 35b, and the spiral fin 35b is bitten into the outer peripheral surface of the inner spiral grooved tube 3. A plurality of third flow paths R3 having a shape surrounded by spiral fins 35b adjacent to the outer peripheral surface of the inner surface spiral grooved pipe 3 are formed between the inner surface spiral grooved pipe 3 and the inner surface spiral grooved pipe 35. ..
In the structure shown in FIG. 8, since the third flow path R3 is provided in addition to the first flow path R1 and the second flow path R2, it is possible to provide a structure corresponding to three types of refrigerants or heat media.
When manufacturing a multiple twisted pipe 34 with an inner spiral groove having a triple pipe structure, the composite raw pipe F of the raw pipes 1 and 8 shown in FIG. 7 is combined with a raw pipe having a diameter smaller than that of the raw pipe 1 before being manufactured. The twisting process and the drawing process may be performed using the device A.

Further, as the raw tube to be used as described above, either a raw tube having a straight groove or a raw tube having an inner spiral groove may be used. Therefore, for example, the lead angle of the spiral fin 2b and the lead angle of the spiral fin 3b It is also possible to sequentially control the lead angle of the spiral fin 35b to a different angle.
For example, a raw pipe having a straight groove is used as the smallest raw pipe, an inner spiral grooved pipe having a lead angle of 10 ° is used as the second largest raw pipe, and an inner surface having a lead angle of 20 ° is used as the largest raw pipe. A spiral grooved tube is used, and a twisting process and a drawing process are performed using the manufacturing apparatus A under the condition that a lead angle of 10 ° is imparted.
By manufacturing in this way, the lead angle of the smallest inner spiral grooved tube is 10 °, the lead angle of the second largest inner spiral grooved tube is 20 °, and the lead angle of the largest inner spiral grooved tube is 20 °. A multi-twisted tube with an inner spiral groove having a triple tube structure of 30 ° can be obtained.

"Third embodiment"
In the above embodiment, one raw pipe 8 is inserted into the raw pipe 1 to add drawing and twisting, but a composite raw pipe in which a plurality of raw pipes 8 are inserted inside the raw pipe 1 is added. It is also possible to manufacture a multi-twisted tube with an inner spiral groove by the manufacturing apparatus A using the above.
For example, a plurality of (for example, three) pipes having a smaller diameter are inserted into one pipe 1 to prepare a composite pipe, and the entire composite pipe is drawn and twisted. It is possible to manufacture a multi-twisted tube with an inner spiral groove.

In FIG. 9, three small-diameter inner-grooved raw pipes are inserted into one large-diameter inner-grooved raw pipe, and the entire surface is drawn and twisted using the above-mentioned manufacturing apparatus A. An embodiment of the obtained multiple twisted tube with an inner spiral groove is shown.
In the multiple twisted pipe 40 with an inner spiral groove of this embodiment, a large-diameter inner spiral grooved pipe 41 is provided on the outermost layer, and three stranded small-diameter inner spiral grooved pipes 42 are provided inside the large-diameter inner spiral grooved pipe 41. It is provided.
A plurality of spiral grooves 41a and spiral fins 41b are provided on the inner surface of the large-diameter inner surface spiral grooved tube 41 at a predetermined pitch in the length direction. A plurality of spiral grooves 42a and spiral fins 42b are provided on the inner surface of each of the three small-diameter inner spiral grooved pipes 42 at a predetermined pitch in the length direction, and each of the small-diameter inner spiral grooved pipes 42 has a substantially triangular shape. Is formed in.

FIG. 10 is a perspective view showing a state in which the inner spiral grooved tube 41 of the outermost layer is removed, and three inner spiral grooved tubes 42 having a stranded structure housed therein are taken out. As shown in FIG. 10, the three inner spiral grooved tubes 42 are twisted at a predetermined cycle.
In the multiple twisted pipe 40 with an inner surface spiral groove of this embodiment, the period (twisted wire pitch) of the spiral groove 42a formed on the inner surface of the inner surface spiral grooved pipe 41 of the outermost layer and the twisted wire are formed inside the spiral groove 42a. The cycles (twisted wire pitches) of the three inner spiral grooved tubes 42 are substantially the same.
This is obtained by inserting three small-diameter inner-grooved raw pipes into one large-diameter inner-grooved raw pipe, and drawing and twisting the entire surface using the manufacturing apparatus A. This is because of the fact. A first flow path R1 is formed inside the small-diameter inner spiral grooved pipe 42, and a second flow path R1 is formed inside the large-diameter inner spiral grooved pipe 41 and outside the small-diameter inner spiral grooved pipe 42. Flow path R2 is formed.

The multi-twisted tube 40 with an inner spiral groove having the structure shown in FIGS. 9 and 10 can be applied to a heat transfer tube for connecting an automobile capacitor and an evaporator. By individually using the three first flow paths R1 and the second flow path R2, it is possible to realize a structure provided with a heat transfer tube having an efficient heat exchange function.
Normally, two heat transfer tubes are required to connect the capacitor for automobiles and the evaporator, but in the case of the multiple twisted tube 40 with an inner spiral groove shown in FIGS. 9 and 10, the first flow path R1 and the second flow path R1 and the second The flow paths R2 can be used properly, and both can be connected by one multi-twisted pipe 40 with an inner spiral groove.
In that case, the refrigerant or heat medium flowing through the first flow path R1 can efficiently exchange heat with the refrigerant or heat medium flowing through the second flow path R2, so that the heat transfer tube can be connected with high heat exchange performance.

Further, the period of the spiral groove 42a formed inside the inner spiral grooved pipe 42 shown in FIGS. 9 and 10 and the stranded wire pitch of the inner spiral grooved pipe 42 do not have to be the same.
As described above, since the raw pipe having a straight groove on the inner surface and the raw pipe having a spiral groove on the inner surface can be combined and applied to the manufacturing apparatus A, three raw pipes having different inner spiral grooves formed in advance have a large diameter. A multi-twisted tube with an inner spiral groove provided with three inner spiral grooved tubes having a spiral groove with a period different from the stranded wire pitch by inserting into the raw tube and applying drawing and twisting using the manufacturing device A. Can be obtained.

An A3003 alloy with a fin height of 0.25 mm and straight grooves with 50 grooves formed on the inner surface with an outer diameter of 10.0 mm and an inner diameter of 9.0 mm is used as an outer tube, and an inner surface with an outer diameter of 8.5 mm and an inner diameter of 7.8 mm. A3003 having a fin height of 0.2 mm and a straight groove having 55 grooves was used for the inner peripheral tube to prepare a composite raw tube F having the configuration shown in FIG. The composite raw tube F is subjected to a torsional drawing process under the conditions of a drawing die hole diameter of φ8.5 mm and a drawing speed of 1.0 m / min using the manufacturing apparatus A shown in FIGS. Manufactured a twisted tube.

First, the relationship between the machining area length and the limit twist angle (maximum twist angle that twists without buckling) is increased by increasing the revolution speed of the unwinding side capstan, and the machining area length is 160 mm and the rear tension is 5. When it was manufactured under the above conditions with a weight of about 20 kg, it was possible to manufacture a multi-twisted tube with an inner spiral groove having a cross section as shown in FIG.
FIG. 11 shows a cross-sectional view (see FIG. 11 (A)) and a partially enlarged view (see FIG. 11 (B)) of the sample produced under the above conditions.
The obtained multi-twisted tube with an inner spiral groove has an outer diameter of 8.45 mm, a wall thickness of 0.55 mm, a fin height of 0.2 mm, and an outer diameter of 6.95 mm and a wall thickness of 0.40 mm inside 50 grooves. It was a multi-twisted tube with an inner spiral groove having a structure in which a tube with an inner spiral groove having a fin height of 0.2 mm and 55 grooves was integrated.

Next, when constructing a composite raw pipe made of an aluminum alloy equivalent to the previous example, the outer diameter, bottom wall thickness, fin height, and lead angle of the small diameter raw pipe and the large diameter raw pipe are changed respectively. Multiple twisted tubes with inner spiral grooves were prepared. Table 1 below shows the measurement results of the outer diameter, bottom wall thickness, fin height, and lead angle of the obtained multi-twisted tube with an inner spiral groove.

Examples 1 to 12 in Table 1 have a double pipe structure made of an aluminum alloy, the inner diameter spiral grooved pipe on the large diameter side has an outer diameter of 5 to 12 mm, and the inner diameter spiral grooved pipe on the small diameter side has an outer diameter. It was possible to manufacture a multi-twisted tube with an inner spiral groove having a lead angle of 10 to 20 ° and a diameter of 3.6 to 10.6 mm.
As shown in Examples 1 to 12, a multi-twisted tube with an inner spiral groove provided with an aluminum alloy inner spiral grooved tube having an extremely small diameter such as an outer diameter of 3.6 to 12 mm and easily buckling. It could be manufactured by the manufacturing apparatus A having the configuration shown in FIGS. 3 to 5.

A ... Manufacturing equipment, F ... Composite element pipe, L ... Length of twisting region, R1 ... First flow path, R2 ... Second flow path, 1 ... Elementary tube, 1A ... Tube body, 1a ... Straight groove 1, 1b ... fins, 2 ... inner spiral grooved pipes, 2a ... spiral grooves, 2b ... spiral fins, 3 ... inner spiral grooved pipes, 3a ... spiral grooves, 3b ... spiral fins, 4 ... inner spiral grooved multiple twisted pipes 5, ... Unwinding side capstan, 5a ... Disk part, 6 ... Rotating means, 7 ... Pulling die, 8 ... Helix, 8a ... Straight groove, 8b ... Fin, 9 ... Pulling side capstan, 10a, 11a ... Bearing Part, 12 ... bearing part, 13 ... hollow shaft part, 13a ... one end, 13b ... other end, 13c ... inlet part, 13d ... exit part, 15 ... first support frame, 15a ... tip part, 16 ... second support frame , 17 ... extension frame, 18 ... weight, 20 ... support plate, 21, 25 ... drive motor, 21a, 25a ... output shaft, 22 ... power transmission device, 23 ... strut member, 24 ... support mount, 26 ... tank, 27 ... Flexible supply pipe, 28 ... Horizontal axis, 31 ... Cylinder member, 31a ... Thumbscrew, 32 ... Tension adjuster (front tension applying means), 33 ... Tension adjusting tool (rear tension applying means), 34 ... Inner surface spiral groove With multiple twisted pipes, 35 ... inner spiral grooved pipes, 35a ... spiral grooves, 35b ... spiral fins, 40 ... multiple twisted pipes with inner spiral grooves, 41 ... inner spiral grooved pipes, 41a ... spiral grooves, 41b ... spiral fins , 42 ... Inner surface spiral grooved tube, 42a ... Spiral groove, 42b ... Spiral fin.

Claims (13)

Prepare a plurality of raw pipes with different diameters in which multiple grooves along the length direction are formed on the inner surface at intervals in the circumferential direction, and insert a small diameter raw pipe into the large diameter raw pipe to make a composite element. A pipe is formed, the composite raw pipe is wound around the unwinding side capstan from the direction of its introduction side tangent, the composite raw pipe is unwound along the lead-out side tangent, and the unwind-side capstan is wound on the lead-out side tangent. by rotating around the axis as an axis, the steps of the composite blank tube from the unwinding side capstan unwinding base pipe unwound in the extending direction of the tangent line while rotating the Ri said Jikukai, unwound the A method for manufacturing a multi-twisted tube with an inner spiral groove, which comprises a twist-pulling step of passing a composite raw tube through a drawing die to apply twist while reducing the diameter to obtain a multi-twisted tube with an inner spiral groove. The method for manufacturing a multi-twisted pipe with an inner spiral groove according to claim 1 , wherein a raw pipe having a straight groove on the inner surface is used as a groove along the length direction. The method for manufacturing a multi-twisted tube with an inner spiral groove according to claim 1 , wherein a raw tube having an inner spiral groove is used as the groove along the length direction. Manufacturing method of the inner surface helical grooved multiple torsion tube according to any one of claims 1 to 3, characterized in that 5 to 40% of radial contraction rate by the drawing die. The position to start sending the composite blank tube into the drawing die side from a position between the take-out-out side capstan start winding the composite element tube to the winding-out-out side capstan and the rotating shaft of the take-out-out side capstan by shifting in a direction parallel to any one of claims 1 to 4, characterized in that between the drawing die and the take-out-out side capstan and twist processing area of the composite base pipe The method for manufacturing a multi-twisted tube with an inner spiral groove according to the above. Wherein when diameter reduction while twisting the composite base pipe through said composite mother tube drawing die, any one of claims 1 to 5, characterized in that the addition of forward tension and backward tension to the composite base pipe The method for manufacturing a multi-twisted tube with an inner spiral groove according to the item. Production of the inner surface helical grooved multiple torsion tube according to any one of claims 1 to 6, characterized in that winding on the inner surface helical pull side capstan multiple torsion tube grooved passed through the drawing die Method. The method for manufacturing a multi-twisted tube with an inner spiral groove according to claim 7, wherein the multi-twisted tube with an inner spiral groove unwound from the pull-out side capstan is shaped by a second drawing die. Among a plurality of metal pipes having different diameters in which a plurality of grooves along the length direction are formed on the inner surface at intervals in the circumferential direction, a composite pipe in which a small diameter pipe is inserted into a large diameter pipe is used. Is freely wound from the direction of the introduction side tangent, and is freely unwound along the lead-out side tangent line parallel to the introduction side tangent line. Manufacture of a multi-twisted tube with an inner spiral groove, which comprises a rotating means for rotating around an axis as an axis and a drawing die for reducing the diameter and twisting through the composite element tube unwound from the unwinding side capstan. Device. The composite begin sending raw tube position from the position and the winding-out-out side capstan start winding the composite element tube to the winding-out-out side capstan to the drawing die side, the axis of rotation of the take-out-out side capstan and is offset in a direction parallel to, the inner surface helical according to claim 9 in which between the unwinding position of the out side capstan-out the winding and the drawing die is characterized in that it is a twisting processing area of the base pipe Grooved multiple twisted pipe manufacturing equipment. A front tension applying means for applying a front tension to the composite raw pipe is provided on the front stage side of the unwinding side capstan, and a rear stage for applying a rear tension to the multi-twisted pipe with an inner spiral groove on the rear stage side of the drawing die. The apparatus for manufacturing a multi-twisted tube with an inner spiral groove according to claim 9 or 10 , wherein the tension applying means is provided. The inner spiral according to any one of claims 9 to 11 , wherein a pull-out side capstan for winding and unwinding the multi-twisted tube with an inner spiral groove is provided on the rear side of the pull-out die. Grooved multi-twisted pipe manufacturing equipment. The apparatus for manufacturing a multi-twisted tube with an inner spiral groove according to claim 12, wherein a second drawing die for shaping the multi-twisted tube with an inner spiral groove is provided on the rear side of the capstan on the pull-out side. ..

Images