JP2012236225A - Method and device for manufacturing inner helically grooved pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an inner helically grooved pipe that can obtain an inner helically grooved pipe having high dimensional accuracy and a high fin height, and also can be compatible with a thin pipe and is excellent in productivity.SOLUTION: The method for manufacturing an inner helically grooved pipe includes: a winding step of winding a pipe material 11 in which a plurality of linear grooves 11a along a longitudinal direction are formed in an inner surface while being spaced apart from each other in a circumferential direction, around a winding roller 21 in a coil shape; and a pulling step of extending the coiled pipe material 11C formed via the winding step so as to transform the coiled pipe material into a straight pipe shape while applying a constant tensile force to the coiled pipe material along a coil axis line 26 thereof, to twist the pipe material 11.

Description

  The present invention relates to a method and a manufacturing apparatus for continuously manufacturing an internally spiral grooved tube used for a heat transfer tube of a heat exchanger.

In heat exchangers for air conditioners and the like, heat exchange is performed by inserting heat transfer tubes in order to pass the refrigerant through the aluminum fin material. In recent developments of air conditioners and the like, heat transfer tubes, which are one of the components, are required to have higher performance in response to demands such as improvement of unit performance accompanying energy saving or replacement of the working medium HCFC22. It has been. At present, an inner grooved tube having a spiral groove continuous on the inner surface is mainly used, and the heat exchange efficiency is improved.
As a method of manufacturing an internally grooved tube, a method of pulling out while twisting with a rotating die in the circumferential direction of the tube around the winding direction on the production line (Patent Document 1 and Patent Document 2), or high-speed rotation A groove rolling method (Patent Document 3) has been adopted in which a tube is pressed against a grooved plug with a ball bearing and pulled out while rolling a twisted groove on the inner surface of the tube.

JP-A-62-240108 Japanese Patent No. 3489359 JP-A-6-190476

However, in Patent Document 1 and Patent Document 2, since the twisted tube itself is always rotating on the winding line, the coiled tube on the supply side or the winding side is twisted in the same direction as its twisting direction. It is necessary to rotate in synchronism with the speed, the equipment needs to be enlarged, and the production speed is limited. Further, the sample slides between the die and the sample at the rotary die portion, and it is difficult to generate a constant twist angle even if the rotation is controlled, and the variation of the twist angle in the longitudinal direction is large.
In Patent Document 3, a grooved plug is inserted inside the tube and the inner wall is rolled. However, when the twist angle is increased, the deformation resistance increases due to friction between the plug and the inner wall, and the sample is pulled out. At times, there are problems such that the sample is easily broken and it is difficult to roll a fin having a high height. Furthermore, it is difficult to cope with a tube having a small diameter.

  The present invention has been made in view of such circumstances, and an internal spiral grooved tube with high dimensional accuracy and high fin height can be obtained, and it can be applied to a thin tube and has excellent productivity. It is an object of the present invention to provide a method and an apparatus for manufacturing a pipe.

The method for manufacturing an internally spiral grooved tube of the present invention is a winding step of winding a tubular material in which a plurality of linear grooves along the length direction are formed on the inner surface at intervals in the circumferential direction on a winding roll. And a tensioning step of twisting the tubular material by stretching the coiled tubular material formed through the winding step into a straight tube while applying a constant tension along the coil axis. And
According to the present invention, it is possible to cause a certain twist in the tube material by stretching the coiled tube material wound around the winding roll while applying tension in the coil axis direction. Here, the length in the longitudinal direction when the tube is twisted by one turn is referred to as a twist cycle. The control of the twist cycle depends on the diameter of the winding roll that winds the tube and the winding pitch. That is, when winding is performed at a constant winding pitch, as the diameter of the winding roll used for winding decreases, the diameter of the pipe material that flows in a spiral shape formed during stretching decreases. As a result, the twist cycle is shortened. The twist angle of the tube material increases as the twist cycle becomes shorter.
Further, in the manufacturing method according to the present invention, it is not necessary to insert a plug or the like inside and mechanically process it in advance, unlike the mainstream groove rolling method, because the tube material is twisted. By forming a deep groove on the inner wall of the pipe material during extrusion, a thin inner surface spiral grooved tube having an inner surface groove with high dimensional accuracy can be obtained as it is.

The method for manufacturing an internally spiral grooved tube of the present invention is performed by alternately repeating the winding step and the pulling step a plurality of times.
Since only the winding process and the pulling process are repeated, the manufacturing method is relatively simple, the manufacturing speed can be increased according to the winding speed and the pulling speed, and the productivity is excellent.

In the method of manufacturing an internally spiral grooved tube according to the present invention, the pulling step chucks the coiled tube material for a plurality of turns sent along the axis of the winding roll from the winding roll. Then, after the chucking process of stretching along the coil axis of the coiled tube material, it is preferable to form a straight tube by applying a tension.
By stretching the coiled tube material to some extent in advance, the tension can be applied smoothly. In addition, since the pulling process has a configuration in which a plurality of turns of the coiled tube material fed from the winding roll are stretched along the coil axis, the winding process and the pulling process are sequentially performed for each part of the preceding tube material. It can be repeated and processed continuously.

In the method of manufacturing an internally spiral grooved tube according to the present invention, the tensioning step is performed by chucking both ends of the coiled tube material and extending the coiled tube material along its coil axis, and then applying a tension. It is preferable to form a straight tube.
The present invention can be applied to the production of a relatively short inner spiral grooved tube, and the apparatus can be miniaturized by separately performing the winding process and the pulling process.
In this case, the coiled tube material formed in a coil shape is removed from the take-up roll, and both ends of the coiled tube material are chucked and stretched along the coil axis, whereby the tube material can be twisted uniformly. The twist angle in the longitudinal direction of the inner spiral grooved tube can be stabilized. Moreover, tension can be smoothly applied by extending the coiled tube material to some extent in advance.

In the method for manufacturing an internally spiral grooved tube according to the present invention, in the winding step, the pipe material is formed along the groove by a guide plate formed so that a groove having a constant pitch forms at least a part of the spiral. The winding may be performed while being pressed against the winding roll.
By winding the tube material while pressing it against the surface of the winding roll with the guide plate, it is possible to perform winding while maintaining a constant interval along the groove, and stabilize the twist angle in the longitudinal direction of the internally spiral grooved tube. be able to.

In the method of manufacturing an internally spiral grooved tube of the present invention, after the pulling step, at least one drawing step with a drawing die having a hollow hole for correcting the cross-sectional shape of the tube material, and a heat treatment step for heating the tube material after correction. It is good to have.
By repeating the winding process and the pulling process, the twist angle of the tube material increases and increases, but when these processes are repeated multiple times, when the tube material is wound on the winding roll, Since the tube material is pressed, the cross-sectional shape of the tube material is gradually flattened. In the pipe material having a large cross-sectional flatness, stress is likely to be concentrated in part during winding, and as a result, buckling tends to occur. When buckling occurs at one end, necking occurs at that portion during subsequent twisting, and twisting cannot be applied uniformly in the longitudinal direction of the tube material. Note that the necking referred to here indicates that kinking occurs as if bent locally. Therefore, by performing the drawing process every time the process is repeated a certain number of times, the roundness of the flat tube material can be recovered and buckling can be prevented. In addition, by heating the tube after straightening of roundness, strain can be removed and repeated tensile processing can be performed.

In the method for manufacturing an inner surface spiral grooved tube of the present invention, in the winding step, the winding roll is heated, and the tube material is heated while being wound by the heat of the winding roll.
Moreover, in the manufacturing method of the internal spiral grooved tube of the present invention, in the pulling step, the tube material may be stretched while being heated.
By repeating the winding process and the pulling process, the tube material becomes difficult to twist due to work hardening, but the strain can be removed by heating the tube material. For example, in the winding process, it is possible to heat the surface layer of the winding roll by arranging a sheathed heater perpendicular to the circumferential direction of the winding roll. It is also possible to put it in the box. In the latter case, the passage of the pipe material is performed using a hole provided in the high temperature bath. Moreover, when heating a pipe material in a tension | pulling process, the infrared heating furnace using the radiant heat by the high frequency heating furnace which can be heated at high speed, or a halogen lamp can be used.

The internal spiral grooved pipe manufacturing apparatus of the present invention includes a winding means for winding a tubular material in which a plurality of linear grooves along the length direction are formed on the inner surface at intervals in the circumferential direction on a winding roll. The coil-shaped tube material formed in a coil shape is stretched along the coil axis while applying a constant tension, and is provided with a tension means for forming the coil-shaped tube material in a straight tube shape.
In the inner spiral grooved tube manufacturing apparatus of the present invention, the winding means sandwiches the tube material between the winding roll that winds the tube material in a coil shape, and the winding roll, and the winding A feed roll that continuously feeds the pipe material along the roll surface, and a groove having a constant pitch that sandwiches the fed pipe material between the take-up roll and guides the take-up, at least the take-up roll. And a guide plate formed so as to constitute a part of a spiral along the outer peripheral surface.
In the inner spiral grooved tube manufacturing apparatus of the present invention, the winding means sandwiches the winding material between the winding roll and the winding roll for winding the tubular material in a coil shape, and winds the winding material. The groove having a constant pitch for guiding the guide is constituted by a guide plate formed so as to constitute at least a part of a spiral along the outer peripheral surface of the winding roll.
In the manufacturing apparatus of the inner surface spiral grooved pipe of the present invention, it is preferable to have a drawing means for correcting the cross-sectional shape of the tube material and a heat treatment means for heating the tube material after correction.
In the inner spiral grooved tube manufacturing apparatus according to the present invention, the pulling means sandwiches the tube material by at least two pairs of pinch rolls arranged at intervals along the coil axis of the coiled tube material, and is constant. It is good to be the structure stretched | stretched in a straight pipe | tube, applying the tension | tensile_strength.
In the inner spiral grooved pipe manufacturing apparatus according to the present invention, the pulling means includes a plurality of turns of the coiled pipe material fed along the extension line of the winding roll axis from the winding roll. It is preferable that a stretcher that is king and stretched along the coil axis of the coiled tube material is provided.
In the manufacturing apparatus of an inner surface spiral grooved tube of the present invention, the pulling means is wound by the winding roll and chucked at both ends of a coiled tubular material formed in a coil shape, and the coil of the coiled tubular material A stretcher for stretching on the axis may be provided.
In the manufacturing apparatus of an inner surface spiral grooved tube of the present invention, it is preferable that a heating unit for heating the tube material is provided in at least one of the winding unit and the pulling unit.

  According to the present invention, an internal spiral grooved tube with high dimensional accuracy and high fin height can be obtained, and an internal spiral grooved tube that can cope with a thin tube (thinner diameter) and has excellent productivity is manufactured. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows 1st Embodiment of the manufacturing apparatus of the internal spiral grooved tube which concerns on this invention. It is a figure explaining the pipe material in which the linear groove | channel was formed in the inner surface, (a) is a front view, (b) is a sectional side view. It is a sectional side view which shows an internal spiral grooved pipe | tube. It is a schematic diagram explaining the manufacturing process of an internal spiral grooved pipe. It is a flowchart explaining the manufacturing process of an internal spiral grooved pipe. It is a figure explaining flatness. It is a figure explaining a twist cycle. It is a figure explaining the calculation method of a twist angle. It is a graph which shows the relationship between a winding roll diameter and a twist angle. It is a schematic diagram explaining the winding process of 2nd Embodiment. It is a schematic diagram explaining the tension | pulling process of 2nd Embodiment, (a) shows the correction by a stretcher, (b) shows the correction by a pinch roll.

Hereinafter, an embodiment of a manufacturing method of an inner spiral grooved tube using an inner spiral grooved tube manufacturing apparatus according to the present invention will be described with reference to the drawings.
The manufacturing apparatus 100 for an internally spiral grooved tube according to the first embodiment is provided with a pipe material 11 (see FIG. 2) in which a plurality of linear grooves 11a along the length direction are formed on the inner surface at intervals in the circumferential direction. This is an apparatus for producing an inner surface spiral grooved tube 11R (FIG. 3) that twists and has a spiral groove on the inner surface.
As shown in FIGS. 1 and 4, the manufacturing apparatus 100 is formed in a coil shape by winding means 20 that winds a tube material 11 having fins 11 b formed by linear grooves 11 a on the inner surface thereof on a winding roll 21. The coiled tubular material 11C is stretched along the coil axis 26 to form a straight tube, the drawing means 40 for correcting the cross-sectional shape of the tubular material 11, and the heat treatment for heating the straightened tubular material 11 Means 50.

The winding means 20 sandwiches the tubular material 11 between the winding roll 21 that winds the tubular material 11 in a coil shape and the winding roll 21, and continuously pulls the tubular material 11 along the surface of the winding roll 21. A groove with a constant pitch that sandwiches the pipe 11 to be fed between the motor-driven feeding roll 22 and the winding roll 21 and guides the winding is a spiral along the outer peripheral surface of the winding roll 21. And a pair of guide plates 23 formed so as to constitute a part thereof. Further, below the winding roll 21, a pressing roll 24 that is rotatably supported so as to sandwich the tube material 11 between the winding roll 21 is provided. A motor 25 that is a drive source is connected to the feed roll 22.
The pair of guide plates 23 are formed in an arc plate shape facing the outer peripheral surface of the winding roll 21, and grooves 23 a along the outer peripheral surface of the winding roll 21 are formed at regular intervals on the inner surface thereof. It is preferable that at least two 23 are arranged on both sides of the winding roll 21. By passing the tube material 11 between the surface of the winding roll 21 and the groove 23a of the guide plate 23, the tube material 11 is wound in a coil shape, and the wound coiled tube material 11C is wound on the winding roll 21. It can be sent out from the end of the spiral in the direction of extension of the spiral.
On the surface layer of the winding roll 21 and the pressing roll 24, a sheathed heater is arranged perpendicular to the circumferential direction of the rolls. The roll surface temperature is kept high, and the tube material 11 can be heated to a high temperature while the tube material 11 is wound around the surface of the take-up roll 21 and fed out. The surface temperature of these rolls 21 and 24 is preferably RT (room temperature) to 300 ° C.

The pulling means 30 chucks the coiled tubular material 11C for a plurality of turns sent from the winding roll 21 along the extension of the axis of the winding roll 21 (coil axis 26 of the coiled tubular material 11C). A stretcher 31 that extends along the coil axis 26 is provided. Further, two pairs of pinch rolls 32 arranged at intervals along the coil axis line 26 are provided, and the tube material 11 stretched to some extent by the stretcher 31 is sandwiched between these pinch rolls 32 and fixed. It is formed into a straight tube while applying the tension of. Further, the pulling means 30 is provided with a high-frequency heating furnace capable of high-speed heating or a heating furnace 33 using radiant heat, and can be stretched while heating the coiled tube material 11C.
Note that the phrase “along the axis 26 of the coiled tube material 11 </ b> C does not only mean that it coincides with the coil axis 26, but a slight deviation is allowed. However, it is preferable that the stretching of the coiled tube material 11 </ b> C is performed on the coil axis 26.
Further, the drawing means 40 is configured to correct the cross-sectional shape of the pipe material by drawing the pipe material through a drawing die having a hollow hole. The heat treatment means 50 performs the intermediate annealing of the pipe material after the roundness is corrected.
The heating means of the present invention corresponds to a sheathed heater that heats the surfaces of the take-up roll 21 and the pressing roll 24 and a heating furnace 33 that heats the tube material 11 being stretched.

Next, a method of manufacturing the inner spiral grooved tube using the manufacturing apparatus 100 configured as described above will be described.
By the feed roll 22 rotating at a constant speed, the tube material 11 having a linear groove formed on the inner surface is fed out, and the tube material 11 is wound around the surface of the take-up roll 21a so as to form a coil with the same diameter. At this time, the tube material 11 is guided between the surface of the take-up roll 21a, the guide plate 23, and the pressing roll 24, and from the one end side of the take-up roll 21a to the other end along the surface of the take-up roll 21a. It winds along the axis (coil axis 26) of the winding roll 21a toward the side. At this time, the tube material 11 released from the other end side (upper side in FIG. 1) of the winding roll 21a is formed in a coil shape.
Next, a part of a plurality of turns of the coiled tubular material 11C released from the winding roll 21a is chucked by the stretcher 31, and preliminary correction is performed along the coil axis 26 of the coiled tubular material 11C. Add. The pipe material corrected to a state close to a straight tube passes between the two pairs of pinch rolls 32, and is formed into a straight tube while a tension of 0.3 kN or more is applied between these pinch rolls 32.
The stretcher 31 performs preliminary correction on the coiled tube material 11C, and then moves to the original position as shown by a two-dot chain line in FIG. 1 to chuck the end portions of the coiled tube material 11C that are sequentially fed. Repeat preliminary correction. The tube material 11L that has been straightened by the pinch roll 32 is wound around the winding roll 21b in a coil shape.

  The tubular material 11 wound in this way is formed with a spiral groove having a twist angle determined by the diameter of the winding roll 21a and the winding pitch of the tubular material wound by the winding roll 21a. The twist angle increases as the diameter of the winding roll (winding diameter) decreases, and increases as the winding pitch decreases. Since the twist angle depends on the diameter of the take-up roll, it is possible to generate a large twist angle at once by winding it on a take-up roll with a small diameter. It is difficult to wind up. In this case, it is possible to obtain a tubular material having a large twist angle by winding up on a winding roll having a large diameter and adding the twist to the tubular material by repeating the winding process and the pulling process a plurality of times. However, depending on the material of the tube material, the tube material is hardly twisted due to work hardening by repeating the winding process and the pulling process in order to increase the twist angle. Therefore, like the heating furnace 33 and the take-up roll 21 of the present embodiment, a means for heating in-line is provided, and the heated tube material is twisted or heat-treated in the middle of each step. It is preferable to remove the strain. In addition, the heat processing performed in the middle of a process performs the intermediate annealing for 0.5 to 4 hours at 200-350 degreeC, for example to a pipe material.

Further, when manufacturing the inner spiral grooved tube having a larger twist angle, for example, as shown in the flowchart of FIG. 5, the drawing process and the heat treatment process are performed every time the winding process and the pulling process are repeated a certain number of times. .
In the flowchart of FIG. 5, as shown in S101 to S103, after repeating the process consisting of the combination of the winding process and the pulling process three times, the drawing process (S104) and the heat treatment process (S105) are sandwiched for a total of eight times. The winding process and the tensioning process are performed (S101 to S112). And whenever a winding process and a tension | pulling process are repeated, a fixed twist is added to the pipe material 11, and a twist angle can be enlarged gradually.

When the winding process and the pulling process are repeated a plurality of times, the pipe is pressed against the surface of the take-up roll 21 when the pipe is taken up by the take-up roll 21a. As shown in FIG. The shape is gradually crushed flat. Tubing with increased cross-sectional flatness may be buckled during winding, and when the buckled pipe is subjected to a pulling process, it bends locally at the buckled portion (necking). ), A tube material in which a uniform twist angle is formed on the entire tube material cannot be obtained. Therefore, it is preferable to perform at least one drawing process and a heat treatment process for heating the straightened tube material while repeating the winding process and the pulling process.
The drawing process is performed by drawing the pipe material through the hollow hole of the drawing die by the drawing means 40. One drawing process is performed with respect to the diameter of the original pipe material within 120% of the flatness of the pipe material. It is performed so that reduction of 5% or more can be achieved. And the pipe material after roundness correction is heated by a heat treatment process, and distortion is removed. In the heat treatment step, for example, the same heat treatment as described above is performed, and the straightened pipe material is subjected to intermediate annealing at 200 to 350 ° C. for 0.5 to 4 hours.
As described above, when the flattening ratio of the pipe material is increased by repeating the winding process and the pulling process, the roundness can be recovered by the drawing process and the occurrence of buckling can be prevented. By providing at least one drawing process that corrects the cross-sectional shape of the tube material after the pulling process, it is possible to suppress the collapse of the tube material, and to repeat the winding process and the pulling process multiple times. The corner can be increased.
In addition, flatness means the ratio of the maximum diameter X with respect to the minimum diameter Y of a pipe material.

  In the inner spiral grooved tube manufacturing apparatus of the second embodiment, as shown in FIGS. 10 and 11, a plurality of winding means 28 and pulling means 38 provided individually are provided on the inner surface along the length direction. An inner spiral grooved tube 11R (see FIG. 3) is manufactured by processing the pipe material 11 (see FIG. 2) in which the linear grooves 11a are formed at intervals in the circumferential direction in a single shot for each process. Moreover, also in the manufacturing apparatus of the inner surface spiral grooved tube of 2nd Embodiment, the drawing means which corrects the cross-sectional shape of the pipe material 11, and the heat processing means which heats the pipe material 11 after correction similarly to 1st Embodiment. Have.

As shown in FIG. 10, the winding means 28 includes a winding roll 21 that winds the tube material 11 in a coil shape, and a groove with a constant pitch that guides the winding along at least the outer peripheral surface of the winding roll 21. And a pair of guide plates 23 formed so as to constitute a part of the spiral. The take-up roll 21 is connected to a motor 25 as a drive source.
The pair of guide plates 23 are formed in an arc plate shape facing the outer peripheral surface of the winding roll 21, and grooves 23 a along the outer peripheral surface of the winding roll 21 are formed at regular intervals on the inner surface thereof. At least two or more 23 is arrange | positioned at the both sides of the winding roll 21. FIG. Then, by passing the tube material 11 between the surface of the winding roll 21 and the groove 23a of the guide plate 23, the tube material 11 can be wound in a coil shape. A sheathed heater is disposed on the surface layer of the take-up roll 21 as in the apparatus of the first embodiment.

  As shown in FIG. 11A, both ends of the coiled tubular material 11C wound and coiled by the winding roll 21 are fixed to the pulling means 38 by chucking, and the coil axis 26 of the coiled tubular material 11C is fixed. A stretcher 39 extending along the top is provided. Further, as shown in FIG. 11B, two pairs of pinch rolls 37 arranged at intervals are provided, and the tube material 11L stretched by the stretcher 39 is sandwiched between the pinch rolls 37. However, it can be formed into a straight tube while applying a constant tension. The pulling means 38 is provided with a heating furnace as in the apparatus of the first embodiment.

Next, a method of manufacturing the inner spiral grooved tube using the manufacturing apparatus configured as described above will be described.
First, the tube material 11 having a linear groove formed on the inner surface is sandwiched between the winding roll 21 and the guide plate 23, and the winding roll 21 is rotated, whereby a constant pitch is formed along the groove 23a of the guide plate 23. A coiled tube material 11C is formed so as to become (FIG. 10). Then, the guide plate 23 of the winding means 28 is removed, and the coiled tube material 11 </ b> C wound around the winding roll 21 is removed from the winding roll 21.
Next, both ends of the coiled tube material 11C are chucked by the stretcher 39, and preliminary correction is applied along the coil axis 26 of the coiled tube material 11C (FIG. 11A). Then, the pipe material 11L corrected to a state close to a straight tube is formed into a straight tube while being loaded with a tension of 0.3 kN or more between the two pairs of pinch rolls 37 (FIG. 11B), and the winding roll 21 The inner spiral grooved tube 11R (see FIG. 3) in which a spiral groove having a twist angle determined by the diameter of the tube and the winding pitch of the tube wound by the winding roll 21 is formed.

  When manufacturing an inner spiral grooved tube having a larger twist angle, the winding process and the pulling process are repeated. In addition, when the flatness of the pipe material increases by repeating the winding process and the pulling process, the roundness of the pipe material is recovered by performing the drawing process and the heat treatment process, thereby preventing the occurrence of buckling. be able to.

  According to the manufacturing method of the inner surface spiral grooved tube of the present embodiment, the coiled tube material wound around the winding roll is stretched while applying tension along the coil axis line, so that a certain twist is applied to the tube material. Can be generated. Since there is no need to insert a plug or the like inside the tube to form a twist in the tube, it is not necessary to perform mechanical processing. Therefore, by forming a deep groove in the inner wall of the tube before extrusion, the dimensional accuracy is maintained as it is. It is possible to obtain a thin inner spiral grooved tube in which a high inner groove is formed.

Example 1
An internally spiral grooved tube was manufactured using a 3003 aluminum alloy tube material having an outer diameter of 10 mm, an inner diameter of 9.1 mm, and a straight groove formed on the inner surface.
As the tube material, the number of linear grooves on the inner surface was 45 (8 ° / 1 mountain), and fins formed by these linear grooves had a height of 0.28 mm. Using this tube material, the diameter of the take-up roll was varied in the range of 20 to 760 mm in diameter, and after each take-up roll was wound at a take-up pitch of 15 mm, the coil-shaped tube material formed in the coil shape It was stretched along the coil axis (tensile process). In addition, in the pulling process, the lower end of the coiled tube material fed from the winding roll by three turns is straightened with a stretcher in a heating furnace heated to 250 ° C., and then stretched to a certain extent to a straight tube. After that, the tube material that had been cooled to room temperature was straightened into a straight tube while applying a tension of 1 to 2 kN between two pairs of pinch rolls. In addition, on the outer peripheral surface of the pipe material, linear marking is performed in advance along the longitudinal direction, and as shown in FIG. 7, the length in the longitudinal direction when the marking line L is twisted by one turn (twisting cycle). B) was measured. As shown in FIG. 8, the twist angle θ was calculated from the inner circumference length A and the twist cycle B of the pipe material. In FIG. 9, the relationship between the winding roll diameter (winding diameter) obtained by implementing as mentioned above and a twist angle is shown.
As shown in FIG. 9, for example, with a winding diameter of φ160 mm, a twist angle of about 3 ° can be generated at one time. As the winding diameter decreases, the twist angle increases, and an internally spiral grooved tube having a twist angle corresponding to the winding diameter can be manufactured. Further, for each manufactured inner surface spiral grooved tube, when the period of the spiral groove formed on the inner surface by cutting in the longitudinal direction of the tube was confirmed, the period of the inner surface spiral groove and the twisting period B of the marking line are It was consistent.

Next, the inner spiral grooved tube was manufactured by repeating the winding process and the pulling process seven times using the above-described tube material and a 160 mm winding roll.
First, after winding on a winding roll at a winding pitch of 15 mm, the coiled tube material is stretched, the winding process and the pulling process are repeated three times, and then a drawing die having a φ8 mm hollow hole is obtained. The pipe material which was pulled out and collapsed to a flat rate of 118% was restored again to a perfect circle with a flat rate of 103% (drawing step). Thereafter, intermediate annealing was performed at 350 ° C. for 4 hours (heat treatment step), and winding was performed again with a winding roll of φ160 mm at a winding pitch of 12 mm. After performing the winding process and the pulling process three times each, it was extracted with a drawing die having a hollow hole of φ7.5 mm, and heat treatment was performed at 350 ° C. for 4 hours. Next, winding was performed at a winding pitch of 11.25 mm with a winding roll of φ160 mm, and the winding process and the pulling process were performed once. Finally, drawing was performed with a drawing die having a hollow hole of φ7 mm, and finally an internally spiral grooved tube having a twist angle of 21 ° was manufactured.
The winding speed and the drawing speed were 30 m / min. In addition, in the tensioning process, the lower end of the coiled tube material for three turns sent from the take-up roll is straightened with a stretcher and stretched to a certain extent to a straight tube, and then between two pairs of pinch rolls. The straight tube was corrected while applying a tension of 1 to 2 kN.

  Each time the winding process and the pulling process are repeated three times, the rounding of the flat tube material is recovered by performing the drawing process. Can be removed. As a result, the winding process and the pulling process could be further repeated, and an internally spiral grooved tube having a twist angle of 21 ° could be finally produced.

(Example 2)
Next, using an 1100 aluminum alloy tube material having an outer diameter of 3.5 mm, an inner diameter of 3.0 mm, and a straight groove formed on the inner surface, the winding process and the pulling process are repeated a plurality of times to produce an inner spiral grooved tube. Went.
As the tube material, 40 linear grooves (9 ° / 1 mountain) were formed on the inner surface, and fins formed by these linear grooves were used with a height of 0.28 mm. The winding process was performed on a winding roll having a diameter of 75 mm at a winding pitch of 5.5 mm. The surface of the winding roll was wound while being heated to 200 ° C. with a sheathed heater. In the pulling process, the tube material corrected to a certain degree of straight pipe by a stretcher is heated to 250 ° C. by an in-line heating device using infrared radiation heat from a halogen lamp, and then 0.5 kN between two pairs of pinch rolls. A straight tube was corrected while applying a tension of 7 ° to a twist angle of 7 °. After repeating the same process three times, drawing was performed with a drawing die having a hollow hole with a diameter of 3 mm, and finally an internally spiral grooved tube with a diameter of 3 mm and a twist angle of 20 ° was produced. If it says in the flowchart of FIG. 5, the process from S101 to S104 was implemented.

  By repeating the winding process and the pulling process three times each, an internally spiral grooved tube with a twist angle of 21.5 ° can be manufactured, and the flatness is restored from 120% to 100% by the final drawing process. In addition, since the twist angle is slightly reduced at the time of drawing, an internally spiral grooved tube having a twist angle of 20 ° could be finally produced.

  In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 100 Manufacturing apparatus of internal spiral grooved tube 11 Tubing material 11a Linear groove 11b Fin 11R Internal spiral grooved tube 20, 28 Winding means 21, 21a, 21b, 21c Winding roll 22 Feeding roll 23 Guide plate 24 Pressing roll 25 Motor 26 Axis 30, 38 Tensioning means 31, 39 Stretcher 32, 37 Pinch roll 33 Heating furnace (heating means)
40 Pulling means 50 Heat treatment means

Claims (16)

  A winding process in which a tubular material in which a plurality of linear grooves along the length direction on the inner surface are formed at intervals in the circumferential direction is wound around a winding roll in a coil shape, and a coil shape formed through the winding process A method for producing an internally spiral grooved tube, comprising: a pulling step of twisting the tube material by stretching the tube material into a straight tube while applying a constant tension along the coil axis.   The method for manufacturing an internally spiral grooved tube according to claim 1, wherein the winding step and the pulling step are alternately repeated a plurality of times.   The pulling step chucks the coiled tubular material for a plurality of turns sent along the axis of the winding roll from the winding roll, along the coil axis of the coiled tubular material. 3. The method for manufacturing an internally spiral grooved tube according to claim 1 or 2, wherein the tube is formed into a straight tube shape by applying a tension after the stretching chucking step.   The tensile step includes forming both ends of the coiled tube material in a straight tube shape by applying a tension after chucking both ends of the coiled tube material and extending the coiled tube material along its coil axis. A method for producing an internally spiral grooved tube according to 1 or 2.   In the winding process, winding is performed while pressing the tube material against the winding roll along the groove by a guide plate formed so that a groove with a constant pitch forms at least a part of a spiral. The manufacturing method of the pipe | tube with an internal spiral groove as described in any one of Claim 1 to 4 characterized by the above-mentioned.   6. The method according to claim 1, further comprising at least one drawing step by a drawing die having a hollow hole for correcting a cross-sectional shape of the tube material after the pulling step, and a heat treatment step for heating the tube material after correction. The manufacturing method of the internal spiral grooved tube as described in any one of Claims.   The inner surface according to any one of claims 1 to 6, wherein in the winding step, the winding roll is heated and heated while winding the tube material by heat of the winding roll. A method of manufacturing a spiral grooved tube.   In the said tension | pulling process, the said pipe material is extended, heating, The manufacturing method of the internal spiral grooved pipe | tube as described in any one of Claim 1 to 7 characterized by the above-mentioned.   Winding means for winding a tubular material in which a plurality of linear grooves along the length direction on the inner surface are spaced apart in the circumferential direction around a winding roll, and a coiled tubular material formed in a coil shape. An apparatus for producing an internally spiral-grooved tube, comprising: a tension means that stretches while applying a constant tension along an axis and forms the coiled tube material in a straight tube shape.   The winding means sandwiches the tubular material between the winding roll that winds the tubular material in a coil shape and the winding roll, and continuously feeds the tubular material along the surface of the winding roll. A groove having a constant pitch that sandwiches the roll and the pipe material to be fed between the take-up roll and guides the take-up forms at least a part of a spiral along the outer peripheral surface of the take-up roll. An apparatus for producing an internally spiral grooved tube according to claim 9, wherein the guide plate is formed of a guide plate.   The winding means includes at least the winding roll that winds the tube material in a coil shape, and a groove having a constant pitch that sandwiches the tube material between the winding roll and guides the winding. The manufacturing apparatus of the inner surface spiral grooved tube according to claim 9, comprising a guide plate formed so as to constitute a part of a spiral along the outer peripheral surface of the take-up roll.   The apparatus for producing an internally spiral grooved tube according to the present invention comprises drawing means for correcting the cross-sectional shape of the tube material and heat treatment means for heating the tube material after correction. The manufacturing apparatus of the inner surface spiral grooved tube as described in any one of these.   The pulling means is configured to sandwich the tube material by at least two pairs of pinch rolls disposed at intervals along the coil axis of the coiled tube material, and to stretch the tube material while applying a constant tension. The manufacturing apparatus of the inner surface spiral grooved tube according to any one of claims 9 to 12, wherein:   The pulling means chucks the coiled tubular material for a plurality of turns sent along the axis of the winding roll from the winding roll, and extends along the coil axis of the coiled tubular material. An apparatus for producing an internally spiral grooved tube according to any one of claims 9 to 13, further comprising a stretcher that stretches and stretches.   The pulling means is provided with a stretcher for winding with the winding roll, chucking both ends of the coiled tubular material formed in a coil shape, and stretching it on the coil axis of the coiled tubular material. The manufacturing device of the inner surface spiral grooved tube according to any one of claims 9 to 13.   16. The manufacturing of an internally spiral grooved tube according to any one of claims 9 to 15, wherein at least one of the winding means and the pulling means is provided with a heating means for heating the pipe material. apparatus.

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