Coil spring winding machine and manufacturing method

Abstract

A winding machine includes: a conveying unit that conveys a wire in a conveying direction; the spiral forming unit is used for sequentially bending the wire conveyed by the conveying unit along the vertical direction so as to form a spiral spring which spirally extends along the forming direction; a laser heating unit that heats a portion of the wire by irradiating the wire bent by the spiral forming unit with laser light; and a cutting unit for cutting the wire part heated by the laser. With a laser irradiation area on the wire as a reference, when the forming direction is set to be 0 degree, the direction opposite to the conveying direction is set to be 90 degrees, the direction opposite to the forming direction is set to be 180 degrees, and the conveying direction is 270 degrees, a first angle larger than or equal to 0 degree and smaller than or equal to 270 degrees is formed between the laser irradiation direction of the laser heating machine and the forming direction.

Description

Technical Field

[0001] The invention relates to a winding machine for manufacturing a spiral spring and a method for manufacturing a spiral spring. Background Art

[0002] As a manufacturing apparatus for a coil spring, for example, a coil spring forming machine is known as described in Patent Document 1. This coil spring forming machine calculates the position of a cutting portion in advance according to the length of a wire material to be formed into a coil shape, and cuts the wire material while the cutting portion is softened by high-frequency heating.

[0003] On the other hand, there is also known a winding machine that uses laser to cut a wire material to be processed and formed into a spiral shape, for example, a spring manufacturing device described in Patent Document 2.

[0004] In the coil spring forming machine of Patent Document 1, the heating responsiveness of the cut portion is poor when high-frequency heating is used. Moreover, the coil spring forming machine continues to heat the cut portion by high-frequency heating while cutting the wire, so the high-frequency heating may affect the parts used for cutting. In addition, the coil spring forming machine has insufficient responsiveness of high-frequency heating, and it is difficult to maintain a certain spring forming accuracy when winding the wire in a partially heated state.

[0005] On the other hand, the spring manufacturing device of Patent Document 2 requires a high-power laser that can cut the wire. In this case, sputtering may occur due to the irradiation of the laser, and the laser will irradiate not only the wire but also various parts of the spring manufacturing device, so measures must be taken to prevent these situations from occurring.

[0006] In view of this, the present applicant has proposed a method described in Patent Document 3, in which a cutting member such as a cutter is used to cut the portion of the wire heated by the laser. This method can easily cut the wire and obtain a coil spring with a good cut surface.

[0007] Prior art literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 62-50028

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 6-218476

[0010] Patent document 3: Japanese Patent No. 7066880. Summary of the invention

[0011] Problems to be Solved by the Invention

[0012] As described above, there is still room for various improvements in the method of cutting the laser-heated portion of the wire using a cutting member. For example, the laser irradiation direction relative to the irradiation position of the wire needs to be set to suit the site conditions in consideration of heating efficiency, interference with various components, etc.

[0013] One of the objects of the present invention is to provide a winding machine and a method for manufacturing a coil spring, which can improve the manufacturing efficiency of the coil spring and simplify the layout of various components used in manufacturing the coil spring.

[0014] Means of solving problems

[0015] The winding machine of the present invention includes: a conveying unit that conveys a wire along a conveying direction; a spiral forming unit that sequentially bends the wire conveyed by the conveying unit along a vertical direction perpendicular to the conveying direction to form a spiral spring extending in a spiral shape along a forming direction perpendicular to the conveying direction and the vertical direction; a laser heating unit that heats a portion of the wire by irradiating a laser onto the wire bent by the spiral forming unit; and a cutting unit that cuts the portion of the wire heated by the laser.

[0016] Furthermore, a method for manufacturing a coil spring according to the present invention includes: conveying a wire material along a conveying direction; sequentially bending the conveyed wire material along a vertical direction perpendicular to the conveying direction to form a coil spring extending in a spiral shape along a forming direction perpendicular to the conveying direction and the vertical direction; heating a portion of the wire material by irradiating a laser beam to the bent wire material; and cutting the portion of the wire material heated by the laser beam.

[0017] According to one embodiment of the present invention, when the irradiation area of ​​the laser on the wire is taken as a reference, the forming direction is 0°, the opposite direction of the conveying direction is 90°, the opposite direction of the forming direction is 180°, and the conveying direction is 270°, the irradiation direction of the laser of the laser heating machine forms a first angle greater than or equal to 0° and less than or equal to 270° with the forming direction.

[0018] According to another embodiment of the present invention, when the irradiation area of ​​the laser on the wire is taken as a reference, the vertical direction is 0°, and the forming direction is 90°, the direction in which the laser heater irradiates the laser forms a second angle greater than or equal to 5° and less than or equal to 80° with the vertical direction.

[0019] The first angle is preferably greater than or equal to 0° and less than or equal to 180°, and more preferably greater than or equal to 0° and less than or equal to 80°.

[0020] Furthermore, the second angle is preferably greater than or equal to 5° and less than or equal to 45°.

[0021] Effects of the Invention

[0022] According to the present invention, a winding machine and a method for manufacturing a coil spring can be provided, which can improve the manufacturing efficiency of the coil spring and simplify the layout of various components used in manufacturing the coil spring. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic perspective view showing main components of a winding machine according to one embodiment.

[0024] Figure 2 is a schematic front view showing a winding machine according to one embodiment.

[0025] Figure 3 is a flow chart illustrating the operation of a winder according to one embodiment.

[0026] Figure 4 is a schematic perspective view showing a specific example of a spiral forming process using a winder according to one embodiment.

[0027] Figure 5 : is a schematic perspective view showing a specific example of a heating process using a winder according to one embodiment.

[0028] Figure 6 is a perspective view showing a first example of a method of heating and softening a portion of a wire material during a heating process.

[0029] Figure 7 is along Figure 6 Cross-sectional view of the wire along line VII-VII.

[0030] Figure 8 is a perspective view showing a second example of a method of heating and softening a portion of a wire material during a heating process.

[0031] Fig. 9 is along Figure 8 Cross-section diagram of the wire along line IX-IX.

[0032] Fig.10 1 is a schematic perspective view showing a specific example of a cutting process using a winder in one embodiment.

[0033] Fig.11 is a schematic cross-sectional view of the wire after being irradiated with laser.

[0034] Fig.12 is a cross-sectional view showing an example of an appropriate positional relationship between a cutter, a mandrel, and a laser irradiation area.

[0035] Fig.13 The cutter is shown from Fig.12 The position shown is lowered and the wire is cut.

[0036] Fig.14 is in accordance with Fig.12 and 13 Schematic side view of a coil spring cut from wire in the manner shown.

[0037] Fig.15 It is a schematic top view of a winding machine viewed in a direction parallel to a vertical direction according to one embodiment.

[0038] Fig.16 is a schematic partial cross-sectional view of a winder according to one embodiment, viewed in a direction parallel to the conveying direction.

[0039] Fig.17 is a schematic perspective view of a winding machine according to a modified example. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of a winding machine and a method for producing a coil spring according to the present invention will be described with reference to the drawings.

[0041] Figure 1 : is a schematic perspective view showing the main part of the winding machine 100 according to the present embodiment. Figure 2 yes Figure 1 A schematic front view of the winding machine 100 is shown. Figure 1 and Figure 2 As shown, a conveying direction X, a vertical direction Y, a forming direction Z, and a circumferential direction Dθ are defined. The conveying direction X, the vertical direction Y, and the forming direction Z are perpendicular to each other. The conveying direction X is the direction in which the wire 1 is conveyed before being formed into a spiral shape. The forming direction Z is the extension direction (the direction in which the spiral spring grows) of the spiral spring formed by bending the wire 1 into a spiral shape. The circumferential direction Dθ is the winding direction of the wire 1 constituting the spiral spring.

[0042] The winding machine 100 includes a conveying unit 10 , a spiral forming unit 20 , a heating unit (a laser heater 30 ), a cutting unit 40 , and a control unit 50 .

[0043] exist Figure 1 and Figure 2 In the example of FIG. 1 , the conveying unit 10 includes a pair of driving rollers 11, a pair of driven rollers 12, and a wire guide 13. The conveying unit 10 may include more driving rollers 11 and driven rollers 12.

[0044] Each driving roller 11 and each driven roller 12 face each other through the wire 1. When each driving roller 11 rotates, each driven roller 12 rotates through the wire 1. As the rollers 11 and 12 rotate, the wire 1 sandwiched between the rollers 11 and 12 is conveyed along the conveying direction X. The wire 1 is inserted into the wire guide 13. The wire guide 13 guides the wire 1 to move linearly along the conveying direction X and guides the wire 1 to the spiral forming unit 20.

[0045] The spiral forming unit 20 forms the wire 1 conveyed by the conveying unit 10 into a spiral shape. Figure 1 and Figure 2 In the example shown in FIG. 4 , the spiral forming unit 20 includes a first forming roller 21 , a second forming roller 22 and a pitch tool 23 .

[0046] The first forming roll 21, the second forming roll 22, and the pitch tool 23 are arranged in this order along the circumferential direction Dθ. The positions of the first forming roll 21, the second forming roll 22, and the pitch tool 23 in the forming direction Z are different from each other.

[0047] The first forming roller 21 and the second forming roller 22 bend the wire 1 conveyed in the conveying direction X in turn in the vertical direction Y. The bent wire 1 thus extends in the circumferential direction Dθ to draw an arc. The bent wire 1 is guided by a pitch tool 23, which is located at a position offset from the second forming roller 22 in the forming direction Z.

[0048] like Figure 2 As shown, the laser heater 30 irradiates the portion of the spirally formed wire 1 with laser light L. By irradiation with the laser light L, a heated portion 1V having a higher temperature than other portions is formed on the wire 1.

[0049] exist Figure 1 and Figure 2 In the example of FIG. 3 , the laser heating machine 30 includes a laser oscillator 31, an optical fiber 32, and a laser head 33. The laser head 33 includes, for example, a beam spot adjuster.

[0050] The laser oscillator 31 may be, for example, a semiconductor laser that generates laser light L. The optical fiber 32 transmits the laser light L generated by the laser oscillator 31 to the laser head 33. The laser head 33 adjusts the beam shape of the laser light L to a rectangular or circular shape using the above-mentioned beam spot adjuster. As the beam spot adjuster, for example, an optical element such as a beam homogenizer may be used.

[0051] The laser heating machine 30 may further include a measuring device 34 for measuring the temperature of the heating portion 1V. The measuring device 34 has, for example, a sensor for detecting the temperature of the heating portion 1V of the wire 1. The measuring device 34 may be disposed on the side of the cutting unit 40 to avoid interfering with the cutting unit 40. The measuring device 34 may be configured to be away from the cutter 41 in conjunction with the operation of the cutter 41 to avoid interfering with the cutter 41, which will be described later. The measurement result obtained by the measuring device 34 may be used, for example, to control the timing of the cutting unit 40 cutting the wire 1.

[0052] Note that the measuring instrument 34 is not an essential component. That is, various conditions for cutting the wire 1 may be set in advance without using the measuring instrument 34, and the heating portion 1V may be cut by the cutting unit 40 based on the set conditions.

[0053] The laser heating machine 30 may further include a moving stage for moving the laser head 33 toward and away from the heating portion 1V of the wire 1. The moving stage may be, for example, a linear translation stage or a manipulator. If the working distance of the laser head 33 is set long enough or interference with the cutting unit 40 can be avoided, there is no need to use a moving stage.

[0054] The cutting unit 40 cuts the heated portion 1V of the wire 1, the temperature of which after the irradiation of the laser light L is stopped is higher than the temperature before the irradiation of the laser light. Figure 1 and Figure 2 In the example shown in FIG. 4 , the cutting unit 40 includes a cutter 41 and a spindle 42 .

[0055] The cutter 41 is disposed between the second forming roll 22 and the pitch tool 23 in the circumferential direction Dθ. The cutter 41 has, for example, a sharp cutting blade at its tip, and its cutting edge extends along the forming direction Z. The cutter 41 is configured to be movable in the vertical direction Y by a drive mechanism (not shown).

[0056] The mandrel 42 is located inside the first forming roller 21, the second forming roller 22 and the pitch tool 23. The mandrel 42 is as shown in FIG. Figure 2 As shown, it has a semicircular shape along the XY plane and extends longitudinally along the forming direction Z. The mandrel 42 supports the inner circumference of the wire material 1 formed into a spiral shape mainly at the end of the arc surface in the vertical direction Y.

[0057] The control unit 50 controls the conveying unit 10, the spiral forming unit 20, the laser heater 30, and the cutting unit 40. Such a control unit 50 includes a controller 51.

[0058] The controller 51 includes a ROM (Read Only Memory), a CPU (Central Processing Unit), and a RAM (Random Access Memory). The ROM stores a computer program for controlling the conveying unit 10, the spiral forming unit 20, the laser heater 30, and the cutting unit 40. The CPU executes the computer program stored in the ROM. The RAM temporarily stores various data generated during the CPU's execution of the computer program.

[0059] Next, we will refer to Figures 1 to 3 A method of manufacturing the coil spring 2 using the winding machine 100 according to this embodiment is described.

[0060] Figure 3 1 is a flowchart showing the operation of the winding machine 100. The operation shown in the flowchart is mainly realized by the controller 51 executing a computer program. The manufacturing process of the coil spring 2 by the winding machine 100 includes a coil forming process S01, a heating process S02, and a cutting process S03.

[0061] In the spiral forming step S01, the wire 1 is formed into a spiral shape. In the heating step S02 after the spiral forming step S01 is completed, a portion of the wire 1 is irradiated with laser light L, thereby forming a heated portion 1V on the wire 1. The heated portion 1V includes a portion that is softer than other portions (base material) of the wire 1. In the cutting step S03 after the heating step S02 is completed, the heated portion 1V of the wire 1 is cut.

[0062] Figure 4 Schematic perspective view of a winding machine 100 showing a specific example of a spiral forming process S01. In the spiral forming process S01, the conveying unit 10 moves the wire 1 linearly along the conveying direction X through the driving roller 11 and the driven roller 12, and guides the wire 1 to the guide 13. The wire 1 led out from the guide 13 is bent in the vertical direction Y by the first forming roller 21 and the second forming roller 22 to form an arc shape. The wire 1 formed into an arc shape is guided by the pitch tool 23 and formed into a spiral shape with a specified pitch. This operation causes the spiral wire 1 to gradually extend along the forming direction Z.

[0063] Figure 5 1 is a schematic perspective view of a winding machine 100 showing a specific example of the heating step S02. In the heating step S02, the laser heater 30 irradiates the laser L directly onto the portion of the wire 1 formed into a spiral shape near the end of the mandrel 42 (below the cutter 41) in the vertical direction Y. The base material of the wire 1 is heated by the energy of the laser L to form a softened heated portion 1V.

[0064] When the heating process S02 is performed, the conveying of the wire 1 by the conveying unit 10 is stopped. The laser heater 30 is, for example, fixedly set at a predetermined position, and irradiates the laser beam L to a portion of the stopped wire 1 from the position. As another example, when the laser heating device 30 has the above-mentioned moving stage, the laser heating device 30 can irradiate the laser L after bringing the laser head 33 close to the wire 1. In addition, in the heating process S02, the laser heater 30 can irradiate the laser L to the portion of the wire 1 fed in the circumferential direction Dθ without stopping the conveying of the wire 1 by the conveying unit 10. In this case, the movement of the laser heater 30 can be controlled so that the irradiation position of the laser L moves according to the movement of the cutting position caused by winding.

[0065] Figure 6 1 is a perspective view of a wire 1, showing a first example of a method of heating and softening a portion of the wire 1. In this example, a laser heater 30 irradiates a laser beam L1 along an irradiation direction DL toward the surface of the wire 1. The laser beam L1 has, for example, a beam profile that is long in the width direction of the wire 1. A heating portion 1V is formed in an irradiation region 1a of the wire 1 irradiated with the laser beam L1 and its surroundings.

[0066] Figure 7 is along Figure 6 1 is a cross-sectional view of the wire 1 taken along line VII-VII in FIG. The heating portion 1V extends not only to the periphery of the irradiation area 1a on the surface of the wire 1 but also to the inside of the wire 1. In the example shown in the figure, the width WD1 of the laser light L1 in the width direction of the wire 1 is smaller than the diameter R of the wire 1. Therefore, most of the laser light L1 is irradiated onto the wire 1.

[0067] Figure 8 1 is a perspective view of a wire 1, showing a second example of a method of heating and softening a portion of the wire 1. In this example, the laser heater 30 irradiates the surface of the wire 1 with laser light L2 along the irradiation direction DL. The laser light L2 has, for example, a circular beam profile. Similar to the first example, a heating portion 1V is formed in and around the irradiation region 1a of the wire 1 irradiated with the laser light L2.

[0068] Fig. 9 is along Figure 8 1 is a cross-sectional view of the wire 1 taken along the line IX-IX in FIG. The heating portion 1V extends not only around the irradiation area 1a on the surface of the wire 1 but also extends to the inside of the wire 1. For example, the width WD2 (diameter) of the laser light L2 is smaller than the diameter R of the wire 1. Therefore, most of the laser light L2 is irradiated onto the wire 1.

[0069] Heating part 1V can be compared Figure 7 and 9 The example shown in FIG. 1 extends further inside the wire 1. The shape of the laser light L emitted by the laser heater 30 is not limited to the first and second examples.

[0070] In both the first and second examples, the heating portion 1V may include a molten pool in which the base material of the wire material 1 is melted by the energy of the laser light L. The molten pool may extend outside the irradiated area 1 a and around it.

[0071] Fig.10 1 is a schematic perspective view of the winding machine 100 showing a specific example of the cutting step S03. In the present embodiment, the cutting step S03 is performed after the irradiation of the laser light L is stopped. As another example, the cutting step S03 may be performed while the laser light L is irradiated. In the cutting step S03, the heated portion 1V of the wire 1, which has a higher temperature than before the irradiation of the laser light L, is cut by the cutting unit 40. In this way, the manufacture of the coil spring 2 is completed.

[0072] Specifically, in the cutting step S03, the cutter 41 is lowered toward the vicinity of the portion where the wire 1 is supported by the mandrel 42. At this time, the wire 1 is cut by the impact applied by the cutter 41.

[0073] If the heating portion 1V includes a molten pool, the molten pool may solidify during the period after the irradiation of the laser L stops and the cutter 41 starts to operate. In addition, after the cutter 41 is actuated, when the cutter 41 contacts the surface of the wire 1, the heat of the heating portion 1V can be taken away by the cutter 41, causing the molten pool to solidify. In this way, the molten pool solidifies before or during the operation of the cutter 41, thereby preventing the molten metal from adhering to the cutter 41.

[0074] In the cutting process S03, the cutter 41 may be operated according to the measurement result of the temperature of the heating part 1V by the measuring device 34. That is, after the irradiation of the laser L, when the temperature of the heating part 1V drops to a predetermined target temperature, the cutter 41 may be operated. The target temperature may be, for example, a temperature at which the molten base material solidifies. Of course, in the cutting process S03, the heating part 1V may be cut by predetermining the delay time from the stop of the irradiation of the laser L to the start of the operation of the cutter 41, without using the measuring device 34.

[0075] The cut coil spring 2 has a first end 61 including a first end surface 61a and a second end 62 including a second end surface 62a. After one coil spring 2 is manufactured, the above-mentioned coil forming step S01, heating step S02 and cutting step S03 are performed again to manufacture the next coil spring 2. Therefore, the first end 61 and the second end 62 are both cut through the above-mentioned steps.

[0076] As the wire 1 is heated and its temperature rises, the shear force required to cut the wire 1 decreases. Moreover, even if the wire 1 has not yet reached the melting point, the shear force can be reduced. Moreover, this trend does not depend on the diameter of the wire 1. As an example, when the wire 1 is cut by the cutter 41, it is preferred that the temperature of at least a portion of the heating portion 1V is 500° C. or more.

[0077] Fig.11 is a schematic cross-sectional view of the wire 1 irradiated with the laser light L. Here, it is assumed that the surface of the wire 1 is irradiated with Figure 8 The laser L2 of the shape shown in the figure forms a molten pool. In the figure, O represents the irradiation area 1a of the laser L on the outer peripheral surface of the wire 1 (refer to Figure 6 , Figure 8 ). For example, the irradiation center O corresponds to the position irradiated by the peak portion with the highest intensity in the beam profile of the laser L. The irradiation center O can also be considered as the center of the molten pool.

[0078] As described above, when the laser beam L is irradiated onto the wire 1, a heated portion 1V is formed. During or after the irradiation of the laser beam L, a molten pool is formed around the irradiation center O. After subsequent cooling, the molten pool solidifies to form a quench-hardened portion 1C. A heat-affected zone 1H (Heat Affected Zone) is formed around the molten pool. Although the wire is not melted, the heat generated by the irradiation of the laser beam L changes the properties of the base material of the wire 1. Based on this, the heated portion 1V includes the quench-hardened portion 1C and the heat-affected zone 1H.

[0079] Fig.11 The results of measuring the Vickers hardness [HV] of the quench-hardened portion 1C, the heat-affected portion 1H, and the base material of the wire 1 are shown. The quench-hardened portion 1C has a higher hardness than the base material as a whole. On the other hand, the hardness of the heat-affected portion 1H is generally smaller than the hardness of the base material. The hardness of the heat-affected portion 1H gradually increases from the vicinity of the quench-hardened portion 1C toward the base material.

[0080] Therefore, the hardness distribution is not uniform even in the heating portion 1V. Therefore, the relationship between the positions of the cutter 41 and the mandrel 42 and the irradiation area of ​​the laser light L needs to be appropriately determined.

[0081] Fig.12 4 is a cross-sectional view showing an example of an appropriate positional relationship between the cutter 41, the mandrel 42, and the irradiation area of ​​the laser L. In the above-mentioned spiral forming step S01, the wire 1 formed into a spiral shape is fed between the cutter 41 and the mandrel 42. In the feeding direction of the wire 1 (circumferential direction Dθ), a gap G is provided between the end 41a of the cutter 41 and the end 42a of the mandrel 42. Hereinafter, the center of the gap G in the circumferential direction Dθ is referred to as the gap center C.

[0082] exist Fig.12 In the example of , the positions of the gap center C and the irradiation center O are offset in the circumferential direction Dθ. Specifically, the irradiation center O is located closer to the cutter 41 than the gap center C (on the downstream side in the circumferential direction Dθ).

[0083] exist Fig.12 In the example of FIG. 1 , the heated portion 1V includes a molten pool 1P, which becomes the quench-hardened portion 1C after solidification. For example, the molten pool 1P overlaps with the gap center C. In addition, the molten pool 1P overlaps with the end 41a of the cutter 41 in the vertical direction Y.

[0084] On the other hand, the molten pool 1P does not overlap with the end portion 42a of the mandrel 42 in the vertical direction Y. Fig.12 In the example, the end portion 42a of the mandrel 42 overlaps in the vertical direction Y with a portion of the heat-affected portion 1H located on the upstream side in the circumferential direction Dθ of the molten pool 1P.

[0085] Fig.13To indicate that the cutter 41 is in the Fig.12 The position shown is a cross-sectional view of a state in which the wire 1 is cut by descending parallel to the vertical direction Y. As described above, when the wire 1 is cut by the cutter 41, the molten pool 1P has already solidified, or the molten pool 1P solidifies due to heat dissipation caused by contact with the cutter 41. Therefore, a quench-hardened portion 1C is formed during cutting. During cutting, a portion of the molten pool 1P may remain in the heated portion 1V.

[0086] When the tip of the cutter 41 hits the outer peripheral surface of the wire 1 protruding from the end 42a of the mandrel 42, a shear force is applied to the heating portion 1V and its surroundings, causing the wire 1 to break. The cutter 41 is lowered, for example, to the vicinity of the axis of the wire 1. A dent B (depression) caused by the cutter 41 is formed on the cut wire 1, i.e., the coil spring 2. Fig.13 In the example shown in FIG. 1 , the quench-hardened portion 1C and the heat-affected portion 1H overlap with the indentation B, but they may be offset from each other.

[0087] As described above, the heat-affected portion 1H is softer than the quench-hardened portion 1C and the base material of the wire 1. Therefore, when the cutter 41 strikes the wire 1, the heat-affected portion 1H in the heated portion 1V is easily broken. Fig.12 As shown, if the irradiation center O is shifted from the gap center C toward the cutter 41, a load can be effectively applied to the portion of the heat-affected portion 1H located upstream of the molten pool 1P in the circumferential direction Dθ, and the wire 1 can be broken along this portion.

[0088] Fig.14 is in accordance with Fig.12 and 13 Schematic side view of a coil spring 2 cut from a wire material 1 in the manner shown. The coil spring 2 has a first end 61 having a first end surface 61a and a second end 62 having a second end surface 62a.

[0089] The first end surface 61a corresponds to Fig.13 The first terminal 61 has a first irradiation mark M1 of the laser L and a notch B of the cutter 41. The first irradiation mark M1 includes a quench-hardened portion 1C and a heat-affected portion 1H (first heat-affected portion).

[0090] The second end surface 62a corresponds to the fracture surface of the wire 1 remaining on the mandrel 42 when the coil spring 2 is manufactured before the coil spring 2 is separated. The second end 62 has a second irradiation mark M2 of the laser L. The second irradiation mark M2 includes a heat-affected portion 1H (second heat-affected portion). Fig.13 As shown, when the wire material 1 is cut, the second irradiation mark M2 does not include the quench-hardened portion 1C. However, for example, the second irradiation mark M2 may include less quench-hardened portion 1C than the first irradiation mark M1.

[0091] The heat-affected portion 1H included in the first irradiation mark M1 extends over at least a portion of the first end surface 61a. In addition, the heat-affected portion 1H included in the second irradiation mark M2 extends to at least a portion of the second end surface 62a. On the other hand, the quench-hardened portion 1C included in the first irradiation mark M1 does not extend to the first end surface 61a. However, a portion of the quench-hardened portion 1C may extend to the first end surface 61a. In this case, it is preferred that the area of ​​the quench-hardened portion 1C is smaller than the area of ​​the heat-affected portion 1H on the first end surface 61a.

[0092] Next, the irradiation direction DL of the laser light L will be described.

[0093] Fig.15 1 is a schematic plan view of the winding machine 100 viewed parallel to the vertical direction Y. In this figure, Figure 1 The wire 1, the driving roller 11, the wire guide 13, the second forming roller 22, the pitch tool 23, the mandrel 42, etc. are shown, and the main body 110 and the cover 120 of the winding machine 100 are shown by dotted lines.

[0094] The main body 110 contains a driving source and a control unit 50 that share power with the conveying unit 10, the spiral forming unit 20, the cutting unit 40, etc. The main body 110 supports the driving roller 11, the wire guide 13, the second forming roller 22, the pitch tool 23, the mandrel 42, etc., and is located on the side opposite to these components in the forming direction Z. The cover 120 is located on the forming direction Z side relative to the driving roller 11, the wire guide 13, the second forming roller 22, the pitch tool 23, the mandrel 42, etc. Fig.15 In the example shown in FIG. 1 , the cover 120 is not provided near the spirally bent wire 1 . The winding machine 100 does not necessarily need to include the cover 120 .

[0095] exist Fig.15 In the plan view, the irradiation area 1a of the surface of the wire 1 by the laser L is used as a reference, the forming direction Z is defined as 0°, the opposite direction of the conveying direction X is defined as 90°, the opposite direction of the forming direction Z is defined as 180°, and the conveying direction X is defined as 270°. In addition, the angle between the irradiation direction DL of the laser L and the forming direction Z is defined as the first angle θ1. In addition, the portion of the wire 1 (helical spring 2) formed into a spiral shape and located on the mandrel 42 is called the 0th circle P0, and the portion adjacent to the 0th circle P0 in the forming direction Z is called the 1st circle P1.

[0096] The first angle θ1 needs to be determined so that the laser head 33 and the laser light L do not interfere with the coil spring 2 formed into a spiral shape. Fig.15In the example of FIG. 1 , when the laser light L is irradiated onto the irradiation area 1a from the range of 270° to 360° (0°), the laser light L is likely to interfere with the first circle P1. Therefore, in the present embodiment, the first angle θ1 is set within the range R1a of not less than 0° and not more than 270°.

[0097] The second forming roller 22 is arranged in the range of 180° to 270°. Since the second forming roller 22 is close to the irradiation area 1a, when the first angle θ1 is within this range, the laser head 33 and the laser light L are likely to interfere with the second forming roller 22. Therefore, it is more preferable to set the first angle θ1 within the range R1b of 0° to 180°. When the first angle θ1 is within the range R1b, the laser head 33 is located on the upstream side of the irradiation area 1a in the conveying direction X.

[0098] like Fig.12 As shown, it is more advantageous to set the irradiation center O of the laser L downstream of the end 42a of the core shaft 42 in the circumferential direction Dθ (opposite to the conveying direction X) and determine the first angle θ1 within the range R1b, because the laser head 33 and the laser L are less likely to interfere with the cutter 41.

[0099] The body 110 is set within a range of 90° to 180°. In addition, the pitch tool 23 is arranged at about 90°. When the cover 120 is set, interference with the cover 120 must also be avoided. Therefore, it is more preferable to set the first angle θ1 within a range of 0° or more and 80° or less.

[0100] Fig.16 is a schematic partial cross-sectional view of the winding machine 100 viewed parallel to the conveying direction X. In this figure, only the helically bent wire 1 (helical spring 2) and the portion of the mandrel 42 located above the central axis AX of the coil spring 2 are shown.

[0101] exist Fig.16 In the cross-sectional view of , the vertical direction Y is defined as 0° and the forming direction Z is defined as 90° with respect to the irradiation area 1a of the laser L. Also, the angle between the irradiation direction DL of the laser L and the vertical direction Y is defined as a second angle θ2.

[0102] Like the first angle θ1, the second angle θ2 needs to be determined so that the laser head 33 and the laser L do not interfere with the various components of the winding machine 100 or the first turn P1. In order to avoid interference with the main body 110 and the wire 1 after the first turn P1, the second angle θ2 is set at least in the range of 0° to 90°.

[0103] The 0th circle P0 is in contact with the first forming roll 21, the second forming roll 22, the pitch tool 23 and the mandrel 42. On the other hand, since the 1st circle P1 is out of contact with these, the outer diameters of the circles after the 1st circle P1 may become larger than the outer diameter of the 0th circle P0, as shown in the figure.

[0104] Since the cutter 41 is located directly above the irradiation area 1a, it is difficult to set the second angle θ2 to 0°. In addition, in order to avoid interference with the first circle P1 having an outer diameter greater than the outer diameter of the 0th circle P0, the second angle θ2 must be less than 90°. Therefore, it is preferred to set the second angle θ2 within a range R2a of 5° to 80°.

[0105] like Fig.16 As shown in the example of , when the irradiation area 1a is located near the outermost periphery of the wire 1 on the mandrel 42, if the second angle θ2 is large, the irradiation area 1a will expand and the heating efficiency of the wire 1 may decrease. Therefore, even within the range R2a, the second angle θ2 is preferably as small as possible. In one example, when the second angle θ2 is set within the range R2b of 5° or more and 45° or less, good heating efficiency can be obtained.

[0106] It should be noted that the condition that the first angle θ1 belongs to any one of the ranges R1a, R1b, and R1c and the condition that the second angle θ2 belongs to any one of the ranges R2a and R2b do not have to be satisfied at the same time.

[0107] According to the above embodiment, the portion (heated portion 1V) of the spirally bent wire 1 heated by irradiation with the laser L is cut by the cutting unit 40 (cutter 41 and mandrel 42), so the shear force required for cutting can be reduced. Therefore, the wire 1 can be easily cut.

[0108] In addition, by using Fig.15 and Fig.16 By determining the irradiation direction DL of the laser light L as described above, the laser head 33 and various components can be effectively arranged, and interference between the laser light L and various components can be suppressed, thereby improving the heating efficiency of the wire material 1.

[0109] The above-described embodiments do not limit the scope of the present invention to the configurations disclosed in the embodiments. The present invention can be implemented by making various modifications to the configurations disclosed in the embodiments.

[0110] For example, it is obvious that when implementing the present invention, various changes can be made to the configuration and arrangement of each element of the winding machine 100 as needed.

[0111] In each embodiment, the winding machine 100 is configured to cut the heated portion 1V of the wire 1 using the cutter 41. The winding machine 100 is not limited to such a structure, and the heated portion 1V of the wire 1 may be cut using a rotating saw blade.

[0112] The coil spring 2 manufactured by the winding machine 100 can have various shapes, for example, its coil diameter and pitch can be changed in the axial direction of the coil spring. That is, the coil spring 2 manufactured by the winding machine 100 can be various types of coil springs, including cylindrical coil springs, barrel coil springs, hourglass coil springs, conical coil springs, coil springs with unequal pitches, coil springs with negative pitches, etc. The first angle θ1 and the second angle θ2 can be set to appropriate values ​​according to the shape of the coil spring so that the laser L does not interfere with the first coil P1 and subsequent coils.

[0113] In the drawings, a winding machine 100 and a manufacturing method for manufacturing a right-handed coil spring wound clockwise from the end are shown. The configuration disclosed in this embodiment can also be applied to a winding machine and a manufacturing method for manufacturing a left-handed coil spring wound counterclockwise from the end.

[0114] Fig.17 1 is a schematic perspective view showing an example of a winding machine 200 for manufacturing a left-handed coil spring. The winding machine 200 includes similar elements to the winding machine 100. However, Fig.17 In the example, the arrangement position relationship of each element is Figure 1 , Figure 2 , Figure 4 , Figure 5 , Fig.10 The positions shown are reversed.

[0115] exist Fig.17 In the winding machine 200 shown in FIG. 1 , the conveying direction X, the vertical direction Y, and the forming direction Z are defined as follows: Figure 1 , Figure 2 , Figure 4 , Figure 5 , Fig.10 Therefore, regarding the conditions of the first angle θ1 and the second angle θ2, refer to Figures 4 to 7 That explains it.

[0116] The symbols in the drawings of the specification include:

[0117] 1. Wire; 1V. Heating part; 1P. Molten pool; 1C. Quenching hardening part; 1H. Heat affected part; 2. Coil spring; 10. Conveying unit; 11. Driving roller; 12. Driven roller; 13. Wire device; 20. Helical forming unit; 21. First forming roller; 22. Second forming roller; 23. Pitch tool; 30. Laser heater; 31. Laser oscillator; 32. Optical fiber; 33. Laser head; 34. Measuring device; 40. Cutting unit; 41. Cutter; 42. Mandrel; 50, control unit; 51, controller; 61, first end; 62, second end; 100, 200, winder; L, L1, L2, laser; S01, spiral forming process; S02, heating process; S03, cutting process; M1, first irradiation mark; M2, second irradiation mark; B, dent; X, conveying direction; Y, vertical direction; Z, forming direction; Dθ, circumferential direction; DL, irradiation direction; θ1, first angle; θ2, second angle.

Claims

1. A winding machine, comprising: a conveying unit, which conveys the wire along a conveying direction, a spiral forming unit that sequentially bends the wire material conveyed by the conveying unit in a vertical direction perpendicular to the conveying direction to form a spiral spring that extends spirally in a forming direction perpendicular to both the conveying direction and the vertical direction, and a laser heater that irradiates a laser onto the wire material bent by the spiral forming unit to heat a portion of the wire material, A cutting unit for cutting the wire portion heated by the laser, Among them, taking the irradiation area of ​​the laser on the wire as a reference, when the forming direction is set to 0°, the opposite direction of the conveying direction is set to 90°, the opposite direction of the forming direction is set to 180°, and the conveying direction is set to 270°, the direction in which the laser heater irradiates the laser forms a first angle greater than or equal to 0° and less than or equal to 270° with the forming direction.

2. The winding machine according to claim 1, characterized in that: The first angle is greater than or equal to 0° and less than or equal to 180°.

3. The winding machine according to claim 2, characterized in that: The first angle is greater than or equal to 0° and less than or equal to 80°.

4. The winding machine according to any one of claims 1 to 3, characterized in that: Taking the irradiation area as a reference, when the vertical direction is set to 0° and the forming direction is set to 90°, the irradiation direction and the vertical direction form a second angle greater than or equal to 5° and less than or equal to 80°.

5. A winding machine, comprising: a conveying unit, which conveys the wire along a conveying direction, a spiral forming unit that sequentially bends the wire material conveyed by the conveying unit in a vertical direction perpendicular to the conveying direction to form a spiral spring that extends spirally in a forming direction perpendicular to both the conveying direction and the vertical direction, and a laser heater that irradiates a laser onto the wire material bent by the spiral forming unit to heat a portion of the wire material, A cutting unit for cutting the wire portion heated by the laser, Among them, taking the laser irradiation area on the wire as a reference, when the vertical direction is set to 0° and the forming direction is set to 90°, the laser irradiation direction of the laser heater forms a second angle with the vertical direction, and the second angle is greater than or equal to 5° and less than or equal to 80°.

6. The winding machine according to claim 5, characterized in that: The second angle is greater than or equal to 5° and less than or equal to 45°.

7. A method for manufacturing a coil spring, comprising: Wire conveying, conveying wire along the conveying direction, In the spiral forming process, the conveyed wire is bent in sequence in a vertical direction perpendicular to the conveying direction, thereby forming a spiral spring extending in a spiral shape in a forming direction perpendicular to both the conveying direction and the vertical direction. The heating process heats a portion of the wire by irradiating the bent wire with laser light. Cutting process, cutting the wire part heated by the laser, Among them, taking the irradiation area of ​​the laser on the wire as a reference, when the forming direction is set to 0°, the opposite direction of the conveying direction is set to 90°, the opposite direction of the forming direction is set to 180°, and the conveying direction is set to 270°, the irradiation direction of the laser and the forming direction form a first angle greater than or equal to 0° and less than or equal to 270°.

8. The method for manufacturing a coil spring according to claim 7, characterized in that: The first angle is greater than or equal to 0° and less than or equal to 180°.

9. The method for manufacturing a coil spring according to claim 8, characterized in that: The first angle is greater than or equal to 0° and less than or equal to 80°.

10. The method for manufacturing a coil spring according to any one of claims 7 to 9, characterized in that: Taking the irradiation area as a reference, when the vertical direction is set to 0° and the forming direction is set to 90°, the irradiation direction and the vertical direction form a second angle greater than or equal to 5° and less than or equal to 80°.

11. A method for manufacturing a coil spring, comprising: Wire conveying, conveying wire along the conveying direction, In the spiral forming process, the conveyed wire is bent in sequence in a vertical direction perpendicular to the conveying direction, thereby forming a spiral spring extending in a spiral shape in a forming direction perpendicular to both the conveying direction and the vertical direction. The heating process heats a portion of the wire by irradiating the bent wire with laser light. Cutting process, cutting the wire part heated by the laser, Among them, when the laser irradiation area on the wire is used as a reference, the vertical direction is set to 0°, and the forming direction is set to 90°, the laser irradiation direction forms a second angle greater than or equal to 5° and less than or equal to 80° with the vertical direction.

12. The method for manufacturing a coil spring according to claim 11, characterized in that: The second angle is greater than or equal to 5° and less than or equal to 45°.

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