Spiral coil manufacturing device and manufacturing method

Abstract

To provide a spiral coil manufacturing device and manufacturing method of winding a long square pipe having a rectangular cross-sectional shape into a spiral shape while maintaining the shape of the cross-section.SOLUTION: A spiral coil manufacturing device 1 includes: a main forming roll 10 with multiple turns of spiral grooves 12 formed on its peripheral wall; and auxiliary rolls 2a, 2b arranged so as to be close to each other around the main forming roll 10, and spirally winds a square pipe 3 filled with liquid. The cross-sectional shape of the groove 12 has the rectangular shape composed of a pair of side walls that becomes the short side and a bottom wall that is vertical to the side walls and becomes the long side, and has the width equivalent to the outer shape long side of the square pipe 3. A gap between the auxiliary rolls 2 and the bottom wall is the gap equivalent to the outer shape short side of the square pipe 3. The peripheral wall on which the groove 12 is provided is divided into multiple arcuate peripheral wall blocks at specific angles around the axis. The peripheral wall blocks are configured to be detachable toward the inner side of the main forming roll 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for manufacturing a helical coil using a square pipe having a rectangular cross-sectional shape. [Background technology]

[0002] Generally, as shown in Patent Document 1, a pipe bender for bending a round pipe has an approximately semicircular groove on a circular fixed shoe, and a corresponding groove on a movable shoe. The groove prevents the round pipe from being crushed. On the other hand, when bending a square pipe, unlike a round pipe, deformation of the shape occurs, which is a problem. In particular, the side of the bent square pipe is crushed inward, and wrinkles occur on the inner and outer periphery sides. As a technique for bending a square pipe for a frame of a motorcycle while preventing deformation, for example, Patent Document 2 discloses a technique for bending a ribbed aluminum square pipe, in which molten metal obtained by heating a low-melting point alloy is poured into the space between each layer of the square pipe from the other end, the square pipe and the low-melting point alloy are cooled to room temperature, and then bent, and the low-melting point alloy is heated to above its melting point and discharged from the square pipe. The square pipe is bent along the rims of the disk shoes of the pipe bender (same document, Figure 2). It is said that the upper and lower side walls of the square pipe and the side walls between the reinforcing ribs tend to be indented inward, forming concave surfaces (page 2, upper left column, lines 10-13 of the same document). However, with this technology, the side walls of the square pipe are prevented from deforming inward because they come into contact with the solidified metal, and the thickness of the solidified metal in the bending direction does not change, so outward deformation is also prevented.

[0003] Furthermore, Patent Document 3 discloses a technique for bending a round pipe during the process of forming it into a square pipe. In Patent Document 3, when a hollow round pipe for an automobile frame is transformed into a square pipe and bent, a method called hydrobending or hydroforming is used, in which water or oil is sealed in the round pipe and the pipe is pressed from all sides with rolls to form a square pipe with a square cross section. It is said that bending can be performed while suppressing wrinkles and deformation during bending. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-226654 [Patent Document 2] Japanese Patent Application Publication No. 1-122623 [Patent Document 3] JP 2022-110718 A [Patent Document 4] JP 2005-142568 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] In Patent Document 2, it is possible to bend the square pipe while preventing the original square shape and slackness of the surface, but there is a difficulty in handling low melting point alloys. There is also a method in which water is sealed in place of the low melting point alloy and the bending process is performed after freezing, but when bending a long object, a refrigerator suitable for long lengths must be prepared. In addition, since the side walls of square pipes tend to deform inward, the rim of the disk shoe of the pipe bender does not suppress deformation of the side shape of the square pipe, but suppresses the deviation of the square pipe from the disk shoe.

[0006] Furthermore, the technology in Patent Document 3 reports that bending a square pipe from the beginning results in a large change in the shape of the surface, and that bending a round pipe into a square pipe produces better results (ibid., Figure 4). However, it is unavoidable that the corners of the formed square pipe will be rounded and the flat parts will bend.

[0007] Incidentally, a helical coil used for helical resonance, which is a coil made by winding a solid rod in a helical shape, is known, for example, in Patent Document 4. The helical resonator disclosed in this document is used in an apparatus for etching a semiconductor substrate with plasma. Another use of the helical resonator is for contactless power transmission. The helical resonator for these uses is connected to an RF power source, and it is considered that a helical coil with a square cross section is preferable (for example, column 0020 of Patent Document 4). In order to correspond to an RF power source that uses high frequency, a helical coil made of a conductor metal pipe having a cross section similar to that of a hollow rectangular waveguide is more preferable in terms of the efficiency of use of the conductor metal than a helical coil made of a square rod made solid by a conductor metal. And, as such a conductor metal, copper or brass is preferable.

[0008] As a technique for winding a copper pipe into a spiral multiple times, the spiral winding of a round copper pipe for a heat exchanger has long been known. For example, there is a method of winding the copper pipe around a roll, or a method of surrounding a spiral path through which the copper pipe passes with multiple small rolls and winding the copper pipe into a spiral while feeding the copper pipe with the small rolls. In the method of winding the copper pipe around a roll, the diameter of the spiral becomes larger than that of the cylindrical roll when the copper pipe is unwound after winding, and the copper pipe naturally comes off the cylindrical roll. In addition, the method of surrounding a spiral path with multiple small rolls allows the copper pipe to be continuously spiraled.

[0009] However, when a square pipe is wound using these heat exchanger techniques, deformation occurs in the cross section, making it impossible to obtain stable performance as a helical resonator, and therefore this technique cannot be applied.

[0010] An object of the present invention is to provide an apparatus and method for manufacturing a helical coil in which a long square pipe having a rectangular cross-sectional shape of a hollow rectangular waveguide is wound helically while maintaining the cross-sectional shape. [Means for solving the problem]

[0011] The spiral coil manufacturing apparatus of the present invention comprises a forming main roll having a spiral groove of multiple turns formed in its peripheral wall and rotating around an axis, and a plurality of auxiliary rolls arranged in close proximity to each other around the forming main roll and having axes parallel to the forming main roll, and is an apparatus for manufacturing a spiral coil that spirally winds a straight square pipe made of a conductive metal filled with a fluid liquid, wherein the cross-sectional shape of the groove is a rectangle formed by a pair of side walls which form the short sides and a bottom wall which forms the long sides perpendicular to the side walls and has a width corresponding to the outer long side of the cross-sectional outer periphery of the square pipe, the distance between the surface of the auxiliary roll and the bottom wall corresponds to the outer short side of the cross-sectional outer periphery of the square pipe, the peripheral wall in which the groove is formed is divided into a plurality of arc-shaped peripheral wall blocks at specific angles around the axis, and the peripheral wall blocks are configured to be able to drop off toward the inside of the forming main roll. Furthermore, the method for producing a spiral coil of the present invention uses the above-mentioned production apparatus, fills the inside of the square pipe with liquid, closes the front and rear openings with sealing plates, inserts the end of the square pipe between the groove and the auxiliary roll, rotates the main forming roll, and winds the square pipe into the main forming roll. Upon completion of the winding, the peripheral wall block is dropped toward the inside of the main forming roll, and then the other peripheral wall blocks are removed to produce a spiral coil. Effect of the Invention

[0012] According to the present invention, not only can wrinkles that occur on the shortening side of the axial center of the square pipe be dealt with, but the side walls of the grooves of the forming main roll can balance the pushing force of the liquid water to keep the side of the square pipe parallel, which is effective in maintaining the shape of the side of the square pipe. As a result, the square pipe can be formed into a spiral coil while maintaining its cross-sectional shape. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of a spiral coil manufacturing apparatus. [Diagram 2]2A is a perspective view of the forming main roll, FIG. 2B is a diagram explaining the relationship between the grooves in the peripheral wall and the square pipes, and FIGS. 2C to 2E are diagrams showing the disassembly process of the forming main roll. [Diagram 3] FIG. 2 shows a formed spiral coil. [Figure 4] FIG. 1 is a diagram showing a manufacturing apparatus that was produced. [Diagram 5] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [Example 1] An embodiment of a spiral coil manufacturing apparatus 1 according to the present invention is shown. In this embodiment, a square pipe using copper as the conductor metal is formed into a spiral coil with multiple turns. In Fig. 1, the square pipe 3 before forming is straight, and the front and rear openings are sealed by welding copper sealing plates 3a, 3b. One of the sealing plates 3b that seals the front and rear openings is provided with a water inlet 3d and an air outlet 3c.

[0015] The manufacturing apparatus 1 forms a square pipe 3 having a rectangular cross section into a spiral coil. The manufacturing apparatus 1 includes a forming main roll 10, multiple auxiliary rolls 2, and a drive unit 4 that rotates the forming main roll 10 around an axis c. The forming main roll 10 has a spiral groove 12 on its peripheral wall. The multiple auxiliary rolls 2 are smooth cylindrical rolls, and have an axis parallel to the forming main roll 10. In this specification, the term "rectangle" is used in a broad sense including a square. In addition, in this specification, the terms "short side" and "long side" mean "one side" in the case of a square.

[0016] The forming main roll 10 will be described with reference to FIG. 2. In FIG. 2A, the forming main roll 10 has a groove 12 with multiple turns in a spiral shape on the peripheral wall. In this embodiment, one with 8 turns is shown. According to the cross section of the forming main roll 10 in FIG. 2B, the cross section of the groove 12 is rectangular, and is composed of a pair of side walls 12a and 12b that are the short sides of the rectangle, and a bottom wall 12c that is the long side perpendicular to the side walls. The opposite side of the bottom wall 12c is open. The groove 12 has a depth h and a width w. The top surface between the grooves is also a surface parallel to the axis c. The cross section of the square pipe 3 is rectangular, and in the outer peripheral shape of the cross section, the outer short side a and the outer long side b have lengths corresponding to the depth h and width w.

[0017] The outer long side b is slightly narrower than the width w, but this difference is only to the extent that the square pipe can mechanically fit into the groove. On the other hand, the outer short side a is the same as the depth h. The auxiliary roll 2 arranged around the main forming roll 10 acts to maintain the distance of the outer long side b between its surface and the bottom wall 12c.

[0018] The auxiliary rolls 2 have a length that covers the grooves 12 of the forming main roll 10 with multiple turns. The auxiliary rolls 2 are arranged discretely around the forming main roll 10 at two locations on the circumference of the forming main roll 10 in groups of five, and each rotates around its own axis. The square pipe 3 is inserted into the empty space between the groups of auxiliary rolls 2 (the location to the right of the first auxiliary roll 2a of the group on the paper surface of FIG. 2). The diameters of the auxiliary rolls 2 do not all need to be uniform to the same diameter, but in this embodiment, the diameters of the auxiliary rolls 2 are made smaller than that of the forming main roll 10 and are uniform to about one-fifth. The auxiliary rolls 2 of each group are arranged close to each other, and in this embodiment, the angular interval between them is 22.5 degrees. The first auxiliary roll 2a and the adjacent auxiliary roll 2b are arranged close to each other. The angular interval between the two, 22.5 degrees, is an angle that slightly separates the surface of the first auxiliary roll 2a of the group from the surface of the next auxiliary roll 2b adjacent to it. The positional relationship is such that when the tip of the square pipe 3 inserted between the auxiliary rolls 2a reaches the auxiliary rolls 2b, it is guided to the groove 12 side by the auxiliary rolls 2b.

[0019] FIG. 2C shows the process of disassembling the forming main roll 10. The forming main roll 10 can be disassembled into upper and lower bottom plates 11a and 11b and a plurality of peripheral wall blocks 13, 14, and 15. The peripheral wall blocks 13, 14, and 15 are obtained by dividing the peripheral wall of the forming main roll 10 into arcs at specific angles around the axis c. Thus, the grooves 12 provided in the peripheral wall blocks 13, 14, and 15 are divided at specific angles. The specific angles may be common to the peripheral wall blocks 13, 14, and 15, or may be different. The peripheral wall blocks 13, 14, and 15 can be connected to the bottom plates 11a and 11b at their upper and lower surfaces using bolts 5 or the like. In FIG. 2D, in this embodiment, there are six peripheral wall blocks 13, 14, and 15, and they are combined to form the peripheral wall of the forming main roll 10 that has gone around once.

[0020] In Fig. 2E, the six peripheral wall blocks 13, 14, and 15 are designed to be removable inward. In the present embodiment, the two opposing peripheral wall blocks 15 are designed to be removable inward. Specifically, the two side surfaces 15a and 15b of each peripheral wall block 15 that contact the adjacent peripheral wall blocks 13 and 14 are parallel to each other. When this peripheral wall block 15 is pushed inward and removed, the other peripheral wall blocks 13 and 14 also fall off.

[0021] Next, a process for manufacturing the spiral coil 30 using the manufacturing apparatus 1 will be described. The straight square pipe 3 is annealed to soften the copper. The front and rear openings of the square pipe 3 are sealed by welding sealing plates 3a and 3b. The front opening of the square pipe 3 is cut obliquely at an acute angle θ in the length direction and a sealing plate 3a is attached. This is to make it easier to roll it into the manufacturing device 1. Water is filled from the inlet 3d of the sealing plate 3b sealing the rear side of the square pipe, and air is discharged from the outlet 3c. After that, the inlet 3d and the outlet 3c are closed and sealed. A liquid such as oil may be used instead of water. In this example, the internal pressure of the square pipe 3 when it is closed is 0 MPa. One end of the square pipe 3 is inserted between the groove 12 of the forming main roll 10 and the first auxiliary roll 2a.

[0022] When the driving device 4 rotates the forming main roll 10, the square pipe 3 tries to expand slightly while being pushed into the groove 12 by the next auxiliary roll 2b, and is unable to escape between the groove 12 of the inserted forming main roll 10 and the auxiliary rolls 2a and 2b, and the square pipe 3 is rolled up into the groove 12. As the square pipe 3 is rolled up, the surface of the square pipe 3 closer to the axis c receives a compressive force, and the surface farther away receives a tensile force. In addition, both side surfaces receive a bending force. The water inside the square pipe 3 tries to push out the surrounding walls, so the bending force on both sides acts to flatten the square pipe 3, but the side walls 12a and 12b of the groove 12 prevent this. Therefore, the side surfaces of the square pipe 3 are maintained parallel. The auxiliary rolls 2c to 2e following the auxiliary roll 2b ensure that the square pipe 3 is rolled up. In addition, the auxiliary roll 2 has a length sufficient to cover the groove 12 of the multiple turns of the forming main roll 10, so that even when the forming main roll 10 rotates, the square pipe 3 continues to be pressed against the groove 12 at a fixed angle position.

[0023] Furthermore, the wall of the square pipe 3 on the bottom wall 12c side is on the shortening side and therefore tends to wrinkle, but the water in the square pipe 3 presses it against the bottom wall 12c, preventing wrinkles from occurring. The surface of the square pipe 3 on the far side, which is subjected to the tensile force, is pressed by the auxiliary rolls 2 that are discretely arranged around the main forming roll 10, so the square pipe 3 is wound around the main forming roll 10 while remaining in the groove 12.

[0024] The volume inside the square pipe 3 is reduced by being wound around the main forming roll 10, and the water in the pipe, which is a fluid liquid, tries to expand the square pipe 3 throughout its entirety. The pressure of the water in the pipe also acts on the square pipe 3 already wound around the main forming roll 10, but the pressure is blocked by the side walls 12a and 12b of the groove 12. The auxiliary roll 2 also surrounds the main forming roll 10 and blocks the force that tries to return the bend of the square pipe 3 to its original shape. Eventually, the water that has nowhere to go because the internal space of the square pipe 3 is reduced moves to the end P of the square pipe that remains unwound by the main forming roll 10, and expands the outer shape. Figure 3 shows the formed spiral coil, and the end P of the square pipe is expanded (this state can also be seen in Figure 4A). Meanwhile, the cross-sectional shape of the spirally wound part of the square pipe 3 remains rectangular. In this way, by using the grooves 12 and the auxiliary rolls 2, it is possible to achieve an effect similar to that achieved by solidifying a low-melting point metal inside a tube and then bending it, as in Patent Document 2, by using liquid water.

[0025] The winding by the driving device 4 is stopped, and the spiral coil 30 is removed. Figure 4A shows an example of forming a 5 m square pipe 2 into a spiral coil 30. In the figure, the auxiliary roll 2 on the front side has been removed from the forming main roll 10, and the auxiliary roll 2 on the back side remains. At the start and end positions of the winding of the spiral coil 30, the winding diameter of the spiral coil 30 becomes slightly larger due to unwinding, and the spiral coil 30 floats slightly out of the groove 12. On the other hand, the middle part is fixed in the groove 12. This fixation occurs as a result of the outer short side a of the square pipe 3 being pressed against the side walls 12a, 12b of the groove 12 when the square pipe 3 is bent.

[0026] The peripheral wall blocks 13, 14, and 15 are disassembled to remove the spiral coil 30 (see FIG. 4B). Since the spiral coil 30 is fixed to the side walls 12a and 12b of the peripheral wall blocks 13, 14, and 15, the peripheral wall block 15 is pushed inward of the main forming roll 10 to remove it.

[0027] In addition, since the initial annealing treatment of the square pipe generates copper oxide on the surface, which increases the surface roughness, it is preferable to adjust the surface roughness by polishing before winding it around the main forming roll 10. This is because it is possible to control the degree of adhesion between the spiral coil 30 and the peripheral wall blocks 13, 14, and 15 so as not to cause any trouble when removing the spiral coil 30 from the peripheral wall blocks 13, 14, and 15. Also, a lubricant may be applied to the grooves 12 in advance.

[0028] Any portion of the spiral coil 30 that is unstable in shape, such as the unwound end P, is cut off. The spiral coils 30 thus produced are joined by welding to produce a spiral coil having a desired number of turns.

[0029] [Example 2] In Example 1, the sealing plates 3a and 3b were welded to the front and rear openings of the square pipe 3, and after filling the square pipe 3 with water, the inlet 3d and outlet 3c were closed and sealed. As a result, the pressure in the square pipe 3 increased, and the instability of the shape due to the internal pressure was concentrated at the end P. In the example of FIG. 4 of Example 1, when the pressure inside the square pipe 3 was measured, it was initially 0 MPa, but reached 1.2 MPa. In Example 2, the square pipe 3 was modified by attaching a release valve 3e to the outlet 3c as shown in FIG. 5. The release valve 3e had an operating pressure of 0.4 MPa. In addition, before the manufacturing device 1 started winding, the internal pressure of the square pipe 3 was set to 0.4 MPa (the operating pressure of the release valve 3e). The other configurations were the same as in Example 1. The release valve 3e discharges the water inside the square pipe 3 when the pressure of the square pipe 3 becomes 0.4 MPa or more. The cross-sectional shape of the square pipe 3 was maintained as a rectangle, and the length of the end P of the spiral coil 30 that was left unwound could be shortened. In addition, by increasing the pressure inside the square pipe 3 to 0.4 MPa from the beginning, deformation at the start of winding was reduced.

[0030] If a long square pipe is sealed and wound in a spiral shape, the internal pressure will rise and it will become difficult to wind it with the end P remaining unwound, or it will burst. However, if a release valve 3e is attached as in this Example 2 and the internal pressure of the square pipe 2 is kept below a certain value, it will be possible to wind even a long square pipe with little end P remaining unwound.

[0031] According to this embodiment, not only does it deal with wrinkles occurring on the shortening surface on the axis c side of the square pipe 3, but the side walls 12a and 12b are provided on the forming main roll 10, and this balances with the pushing force of the water in the square pipe 3, thereby keeping the side of the square pipe 3 parallel, and is effective in maintaining the shape of the side of the square pipe 3. As a result, the square pipe 3 can be formed into the spiral coil 30 while maintaining its cross-sectional shape. In addition, the peripheral wall blocks 13, 14, and 15 can be disassembled by pushing them inside the forming main roll 10, so the spiral coil 30 fixed to the groove 12 can be easily removed. The auxiliary rolls 2a and 2b can prevent the square pipe 3 from slipping out of the forming main roll 10, so there is no need to provide any additional means or work for fixing the square pipe 3 to the forming main roll 10.

[0032] In this embodiment, the two side surfaces 15a, 15b of the peripheral wall block 15 that contact the adjacent peripheral wall blocks 13, 14 are parallel to each other, but any structure may be used for the peripheral wall blocks 13, 14, 15 to fall off. For example, the side surfaces 15a, 15b may be spaced apart as they approach the axis c. Also, a backup mechanism that supports the peripheral wall blocks 13, 14, 15 from the axis c side may be provided so that the backup mechanism side can be disassembled. Also, in this embodiment, five auxiliary rolls 2 are provided in each group of the auxiliary rolls 2, but only two, the first auxiliary roll 2a and the next auxiliary roll 2b arranged nearby, may be provided. Also, only one group may be provided. [Explanation of symbols]

[0033] 1 Manufacturing equipment 2 Auxiliary roll 3 Square Pipe 3a, 3b blocking plates 3c discharge port 3d injection port 4 drive device 5 bolts 10 forming main roll 11a, 11b bottom plates 12 groove 12a, 12b side walls 12c bottom wall 13, 14, 15 peripheral wall blocks 15a, 15b sides 30 spiral coil

Claims

1. a forming main roll having a spiral groove of multiple turns formed on its peripheral wall and rotating about its axis; a plurality of auxiliary rolls arranged close to each other around the main forming roll and having axes parallel to the main forming roll, the manufacturing apparatus for a spiral coil winding a straight rectangular pipe made of a conductor metal filled with a fluidized liquid into a spiral, The cross-sectional shape of the groove is a rectangle with a pair of side walls as short sides and a bottom wall as a long side perpendicular thereto, and has a width corresponding to the outer long side of the cross-sectional outer peripheral shape of the square pipe, a distance between the surface of the auxiliary roll and the bottom wall corresponds to a short side of an outer peripheral shape of a cross-section of the square pipe, The peripheral wall in which the grooves are formed is divided into a plurality of arc-shaped peripheral wall blocks at specific angles around the axis, and the peripheral wall blocks are configured to be able to drop off toward the inside of the forming main roll.

2. A method for manufacturing a spiral coil using the spiral coil manufacturing apparatus of claim 1, The interior of the square pipe is filled with liquid, and the front and rear openings are closed and sealed with sealing plates. An end of the square pipe is inserted between the first auxiliary roll and the groove, The forming main roll is rotated to wind the square pipe around the forming main roll, When winding is completed, the peripheral wall block is dropped toward the inside of the main forming roll, and thereafter, the other peripheral wall blocks are removed to produce a spiral coil.

3. A method for manufacturing a spiral coil using the spiral coil manufacturing apparatus of claim 1, Filling the inside of the square pipe with liquid, closing the front and rear openings with sealing plates, and attaching a release valve for discharging the liquid from the square pipe; An end of the square pipe is inserted between the first auxiliary roll and the groove, The forming main roll is rotated to wind the square pipe around the forming main roll, When winding is completed, the peripheral wall block is dropped toward the inside of the main forming roll, and thereafter, the other peripheral wall blocks are removed to produce a spiral coil.

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