Method of manufacturing a spring component and control device

Abstract

The method for manufacturing a spring component of the present invention includes: a cold forming step of cold forming a base material to produce a spiral-shaped profile; a quenching step of quenching the profile; and a tempering step of tempering the quenched profile. In the heating of at least one of the quenching and tempering, the first and second energizing components are energized to heat the profile while the two ends of the profile are held by a first energizing component and a second energizing component. In each energizing component, the current ratio R2 is set to a value near the contact area ratio R1, which includes the contact area ratio R1. The current ratio R2 is the ratio of the current flowing through a holding component to the sum of the currents flowing through the energizing component. The contact area ratio R1 is the ratio of the contact area between a holding component and the profile to the sum of the contact areas of the profile and the holding component in the energizing component.

Description

Technical Field

[0001] This invention relates to a method for manufacturing spring components and a control device thereof. Background Technology

[0002] Traditionally, the manufacturing process of helical springs involves either hot forming or cold forming. Hot forming can shape thick wire, but it offers limited freedom in shaping. Cold forming, on the other hand, while offering greater freedom in shaping, is difficult to apply to thick wire. A technique known for its high degree of shape freedom and ability to shape thick wire is one that involves heat treatment such as quenching and tempering after cold forming (see, for example, Patent Document 1). In Patent Document 1, heat treatment is performed by attaching electrodes to both ends of the cold-formed coil (workpiece) and applying an electric current.

[0003] Patent Document 1: Japanese Patent No. 5574772 Summary of the Invention

[0004] However, in heat treatment based on electricity, if the workpiece is to be heated quickly, the amount of electricity supplied to the workpiece must be increased. Sometimes, even if the power is stopped when the workpiece reaches the target temperature, the temperature of the low-temperature part of the workpiece will rise due to heat transfer from the high-temperature part. In this case, the following problems will occur: uneven heating temperatures between workpieces or uneven heat distribution within the workpiece will lead to uneven quality of the manufactured helical springs.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a method for manufacturing spring components and a control device that can reduce the unevenness of the quality of spring components.

[0006] To solve the above problems and achieve the objective, the manufacturing method of the spring component of the present invention is a method for manufacturing a spring component by processing a base material formed from wire, comprising: a cold forming step, wherein the base material is cold-formed to produce a spiral-shaped profile; a quenching step, wherein the profile is quenched; and a tempering step, wherein the quenched profile is tempered. In the heating process of at least one of the quenching and tempering steps, while the two ends of the profile are held by a first energizing component and a second energizing component, the profile is electrically heated by energizing the first and second energizing components. The first energizing component clamps and holds one end of the forming material through a group of gripping components, and the second energizing component clamps and holds the other end of the forming material through a group of gripping components. In each energizing component, the current ratio R2 is set to a value near the contact area ratio R1, which includes the contact area ratio R1, for energizing. The current ratio R2 is the ratio of the current flowing through a gripping component to the sum of the currents flowing through the energizing component, and the contact area ratio R1 is the ratio of the contact area between the forming material and the gripping component to the contact area between the gripping component and the forming material, which is the sum of the contact areas of the forming material and the gripping component in the energizing component.

[0007] Furthermore, the method for manufacturing the spring component of the present invention is to energize the spring by setting the current ratio R2 within the range of the contact area ratio R1 ± 0.1.

[0008] Furthermore, the method for manufacturing the spring component of the present invention involves circulating cooling water inside the energized component, as described above.

[0009] Furthermore, the control device of the present invention is a control device for controlling the manufacturing of a spring component, the manufacturing of which includes: a cold forming process, in which a base material formed from wire is cold-formed to produce a spiral-shaped profile; a quenching process, in which the profile is quenched; and a tempering process, in which the quenched profile is tempered. During heating in at least one of the quenching and tempering processes, while the two ends of the profile are held by a first energizing component and a second energizing component, the first energizing component is energized by a group of... The gripping component clamps and holds one end of the forming material, and the second energizing component clamps and holds the other end of the forming material through a group of gripping components. In each energizing component, the current ratio R2 is set to a value near the contact area ratio R1, which includes the contact area ratio R1. The current ratio R2 is the ratio of the current flowing through a gripping component relative to the sum of the currents flowing through the energizing component, and the contact area ratio R1 is the ratio of the contact area between the forming material and the gripping component in the energizing component to the contact area between the gripping component and the forming material.

[0010] According to the present invention, it can reduce the unevenness of the quality of spring components. Attached Figure Description

[0011] Figure 1 This is a diagram showing the structure of a helical spring manufactured by a manufacturing method according to an embodiment of the present invention.

[0012] Figure 2 This is a diagram illustrating a method for manufacturing a helical spring according to an embodiment of the present invention.

[0013] Figure 3 This is a diagram used to illustrate heating by electricity.

[0014] Figure 4 From Figure 3 The diagram shown is viewed from the direction of arrow A.

[0015] Figure 5 This is a diagram (one of) used to illustrate the setting of the current ratio when heating with electricity.

[0016] Figure 6 This is a diagram (second one) used to illustrate the setting of the current ratio when heating with electricity.

[0017] Figure 7 This is a diagram (third one) used to illustrate the setting of the current ratio when heating with electricity.

[0018] Figure 8 This is a diagram used to illustrate the electric heating of Modified Example 1.

[0019] Figure 9 This is a diagram used to illustrate the electric heating in modified example 2.

[0020] Figure 10 This is a diagram used to illustrate the electric heating in modified example 3.

[0021] Figure 11 yes Figure 10 The AA-line sectional view shown.

[0022] Figure 12 This is a diagram used to illustrate the electric heating in variation example 4. Detailed Implementation

[0023] Hereinafter, the embodiments for carrying out the present invention (hereinafter referred to as "implementations") will be described with reference to the accompanying drawings. Furthermore, the drawings are schematic diagrams, and the relationship between the thickness and width of each part, the ratio of the thickness of each part, etc., may differ from the actual situation. The drawings may also sometimes include parts with different dimensional relationships or ratios.

[0024] Implementation This diagram illustrates the structure of a helical spring manufactured using a manufacturing method according to an embodiment of the present invention. The helical spring 1 is manufactured by winding wire into a helical shape. The helical spring 1 is made, for example, using wire formed of metal or alloy.

[0025] Next, refer to Figures 2-4 The manufacturing method of the helical spring 1 is described. Figure 2 This is a diagram illustrating a method for manufacturing a helical spring according to an embodiment of the present invention. The helical spring 1 is manufactured by processing a base material.

[0026] First, regarding the base material 100 formed from wire (see...) Figure 2 (a)) The wire drawing process is performed to obtain wire drawing material 101 (see Figure 2 (b) In this case, instead of heat treating the base material 100 (drawing material 101), a drawing machine is used to make the diameter of the wire thinner, for example, by passing the base material 100 through a die, thereby obtaining a wire (drawing material 101) of the designed diameter.

[0027] Subsequently, the wire drawing 101 is formed by cold forming (see...). Figure 2 (c) Specifically, the wire drawing material 101 is wound using a winding machine 200. The winding machine 200, for example, is equipped with a winding pin and a cutting tool, which causes the wire drawing material 101 to contact the winding pin to form a shape, and the cutting tool is used to cut the wire drawing material 101 to a specified length.

[0028] The shaped material 102 obtained by winding and cutting the wire 101 is electrically heated (see...). Figure 2 (d) In the electric heating process, a first energizing component 211 is installed at one end of the forming material 102, and a second energizing component 212 is installed at the other end. Current flows through the first energizing component 211 and the second energizing component 212, thereby energizing the forming material 102. Heat is generated by this energization, thereby heating the forming material 102.

[0029] The first energized component 211 and the second energized component 212 are formed of a conductive material, and the movement (gripping of the molding material 102) and energization of the components are controlled by the control device 210.

[0030] After the formed material 102 is electrically heated, the formed material 102 is quenched (see...). Figure 2 (e) The formed material 102 is immersed in a tank 221 containing a water-soluble quenching agent 222. At this time, the temperature and concentration of the water-soluble quenching agent are managed to obtain appropriate heat treatment quality. By immersing the formed material 102 in the water-soluble quenching agent 222, a quenched formed material 103 is obtained. Alternatively, water or oil may be used instead of the water-soluble quenching agent 222.

[0031] After quenching, the formed material 103 is subjected to electric heating for tempering (electric tempering) (see...). Figure 2 (f) In electrical tempering, a first energizing component 231 is installed at one end of the forming material 103, and a second energizing component 232 is installed at the other end. Current flows through the first energizing component 231 and the second energizing component 232, thereby energizing the forming material 103. Heat is generated by this energization, thereby heating the forming material 103. In electrical tempering, in order to reheat the forming material 103 to achieve a specified hardness, the energizing conditions required for reheating are set.

[0032] The first energized component 231 and the second energized component 232 are controlled by the control device 230 to move the components (grip the forming material 103) and energize them.

[0033] Here, refer to Figures 3-5 The control of the energized heating is explained. Furthermore, the energized heating control described herein can be applied to the case of energizing the preform 102 before quenching (see [link]). Figure 2 (d) and the case where the forming material 103 is electrically heated during tempering (see Figure 2 At least one of (f)). Here, when applied to tempering (see Figure 2 Let's take the control of (f) as an example to illustrate.

[0034] Figure 3 This is a diagram used to illustrate heating by electricity. Figure 4 From Figure 3 The diagram is viewed in the direction of arrow A. The first energized component 231 has a first gripping component 231a and a second gripping component 231b, and is located on one end side of the forming material 103.

[0035] The first gripping member 231a is prismatic and located on the outer periphery of the molding material 103. The first gripping member 231a has a planar portion 2311 whose surface in contact with the molding material 103 is planar. Alternatively, the first gripping member 231a may also be cylindrical or other polygonal in shape. Furthermore, the surface of the first gripping member 231a in contact with the molding material 103 may also be curved.

[0036] The second gripping member 231b is cylindrical and located on the inner circumference of the forming material 103. In this case, by making the radius of curvature of the side surface (outer circumferential surface) of the second gripping member 231b smaller than the radius of curvature of the inner circumference of the forming material 103 to which it may be applied, it can be applied to various forming materials 103. Here, the radius of curvature of the inner circumference of the forming material 103 corresponds to a top view taken along the axial direction (winding axis) of the forming material 103 (see...). Figure 4 The radius of curvature of the inner periphery of the forming material 103. In addition, the second gripping member 231b only needs to have a curved surface on the surface that contacts the forming material 103, and other parts can also be polygonal.

[0037] Under the control of the control device 230, the first gripping member 231a and the second gripping member 231b are powered via a live wire (not shown). Furthermore, the first gripping member 231a can move towards or away from the second gripping member 231b under the control of the control device 230. The second gripping member 231b can also move towards or away from the first gripping member 231a under the control of the control device 230. Additionally, to correspond to the winding diameter of the forming material 103, a structure can be formed that allows the second gripping member 231b to move towards the first gripping member 231a; or, to correspond to the number of windings of the forming material 103, a structure can be formed where the first energized member 231 and the second energized member 232 can move towards or away from each other.

[0038] The second energized component 232 has a first gripping component 232a and a second gripping component 232b, and is located on the other end side of the forming material 103.

[0039] The first gripping member 232a is prismatic and located on the outer periphery of the molding material 103. The first gripping member 232a has a planar portion 2321 whose surface is planar on the side that contacts the molding material 103.

[0040] The second gripping component 232b is cylindrical and located on the inner circumference of the forming material 103.

[0041] The first gripping member 232a and the second gripping member 232b of the second energized member 232 can be formed with the same structure as the first gripping member 231a and the second gripping member 231b of the first energized member 231.

[0042] Under the control of the control device 230, the energization of the first energized component 231 and the second energized component 232 is controlled via a live wire (not shown). Furthermore, the first gripping component 232a and the second gripping component 232b are movable under the control of the control device 230.

[0043] The control device 230, for example, positions the molded material 103 in a predetermined position and moves the gripping components of the first energized component 231 and the second energized component 232 to grip one end and the other end of the molded material 103, respectively. Then, the control device 230 allows current to flow through the first energized component 231 and the second energized component 232 via a live wire. Current flows through the contact area between the first energized component 231 and the second energized component 232 and the molded material 103. The heat generated at this time is used to heat the molded material 103.

[0044] Here, refer to Figures 5-7 The control of heating is explained. Figures 5-7 This diagram illustrates the setting of the current ratio during heating, where the contact area ratios between the first energized component 231 and the second energized component 232 are different.

[0045] The current ratio is calculated by accumulating the resistance values ​​along the current transmission path. Here, the current ratio is the ratio of the current flowing through one energized component (here, the second gripping component 232b) to the sum of the currents flowing through the first gripping component 232a and the second gripping component 232b. Specifically, the current ratio is the ratio of the current flowing through the gripping component on the inner diameter side (current side) to the sum of the currents flowing through the energized components (total input) (current side / total input). In the example of the second gripping component 232b, it is (current flowing through the second gripping component 232b) / (sum of the currents flowing through the second energized component 232b).

[0046] Furthermore, the contact area ratio is the percentage of the area of ​​the gripping member that contacts the forming material, calculated based on the shape of the gripping member and the shape of the forming material. This contact area ratio is the ratio of the contact area of ​​a gripping member to the sum of the contact area of ​​one gripping member (here, the second gripping member 232b) with the forming material 103 and the contact area of ​​another gripping member (here, the first gripping member 232a) with the forming material 103.

[0047] Furthermore, the aforementioned ratios were described for the second gripping member 232b of the second energized member, but preferably, the same contact area ratio and current ratio are also maintained in the second gripping member 231b of the first energized member. In this case, "maintaining the same" includes tolerances in materials or manufacturing processes.

[0048] Figure 5 To illustrate the case where the contact area ratio is 0.35, curves showing the relationship between temperature and current ratio for the first and second contact portions are presented, along with a curve showing the relationship between current ratio and temperature at the outer diameter / inner diameter side of the forming material 103 at the 0.2th turn. Here, the first contact portion refers to the part of the forming material 103 contacted by the first gripping member 232a, and the second contact portion refers to the part of the forming material 103 contacted by the second gripping member 232b. It is assumed that the contact position of each contact portion with the forming material 103 is at the 0.08th turn. Figure 5 In the diagram, curve L1 represents the relationship between the current ratio and the temperature of the first contact portion, and is an approximate curve for the temperature measurement point (marked: □) under each current ratio. Curve L2 represents the relationship between the current ratio and the temperature of the second contact portion, and is an approximate curve for the temperature measurement point (marked: 〇) under each current ratio.

[0049] In addition, Figure 5 In the figure, curve L3 represents the relationship between the current ratio and temperature on the outer diameter side of the forming material 103 at the 0.2th ring, and is an approximate curve for the temperature measurement point (marked: ◇) relative to the current ratio. Curve L4 represents the relationship between the current ratio and temperature on the inner diameter side of the forming material 103 at the 0.2th ring, and is an approximate curve for the temperature measurement point (marked: ×) relative to the current ratio.

[0050] At this point, it can be seen from curves L1 and L2 that when the current ratio and the contact area ratio are approximately the same (0.35), the temperatures of the first contact portion and the second contact portion are the same. That is, by making the contact area ratio consistent with the current ratio, when the first gripping member 232a and the second gripping member 232b grip and heat it, the temperatures of the first contact portion and the second contact portion can be made uniform.

[0051] Furthermore, it is known that in the forming material 103, at the 0.2th turn away from the contact position (first and second contact portions) with the gripping component, the temperature is approximately constant regardless of the current ratio.

[0052] Figure 6 This illustrates the temperature relationship between the first and second contact portions relative to the current ratio, assuming a contact area ratio of 0.5. Figure 6 In the middle, curve L 11This is a curve representing the relationship between the current ratio and the temperature of the first contact portion. It is an approximate curve for the temperature measurement points (marked: □) of the first contact portion under various current ratios. Curve L 12 It is a curve representing the relationship between the current ratio and the temperature of the second contact portion, and it is an approximate curve for the temperature measurement point (marked: 〇) of the second contact portion under each current ratio.

[0053] Figure 7 This diagram illustrates the temperature relationship between the first and second contact portions relative to the current ratio, assuming a contact area ratio of 0.6. Figure 7 In the middle, curve L 21 This is a curve representing the relationship between the current ratio and the temperature of the first contact portion. It is an approximate curve for the temperature measurement points (marked: □) of the first contact portion under various current ratios. Curve L 22 It is a curve representing the relationship between the current ratio and the temperature of the second contact portion, and it is an approximate curve for the temperature measurement point (marked: 〇) of the second contact portion under each current ratio.

[0054] like Figure 6 and Figure 7 As shown, the intersection of the two curves is approximately the same as the contact area ratio. That is, it can be said that regardless of the contact area ratio, by making the contact area ratio consistent with the current ratio, when the forming material 103 is gripped and heated by the first gripping member 232a and the second gripping member 232b, the temperature of the first contact portion and the second contact portion of the forming material 103 can be made uniform.

[0055] Furthermore, the current ratio only needs to be close to the contact area ratio, including the same ratio. Specifically, the current ratio can be set to a range R of ±0.1 of the contact area ratio, including the same ratio. A The value within this range can make the temperature of the first contact portion and the second contact portion of the forming material 103 uniform. For example, relative to the contact area ratio R1 of the gripping member, the current ratio R2 can be set within the range of R1 ± 0.1, where the current ratio R2 is the ratio of the current flowing through the gripping member relative to the sum of the currents flowing through the energized members.

[0056] The process involves processing the base material 100 according to the above steps to produce the product. Figure 1 The helical spring 1 shown.

[0057] Annealing can also be performed before or after wire drawing. Furthermore, if the wire diameter is the designed diameter in the base material state, cold forming of the base material 100 can be performed without wire drawing.

[0058] In the above-described embodiments of the present invention, heating is performed by energizing the gripping member for gripping the forming material in such a way that the contact area ratio of the gripping member to the forming material is the same as the current ratio of the current flowing through the gripping member. Therefore, the forming material as a whole can be heated to a uniform temperature. According to this embodiment, quenching / tempering based on uniform heating can improve the shape accuracy of the coil spring, or improve the yield rate by improving shape accuracy, thereby reducing the unevenness of the coil spring's quality.

[0059] Furthermore, according to this embodiment, by employing electric heating during quenching / tempering, CO2 emissions can be reduced.

[0060] Variation Example 1 Next, refer to Figure 8 A variation of this embodiment, Example 1, will be described. Figure 8 This diagram illustrates the energized heating in Modification 1. In Modification 1, the structure of the energized component for energized heating differs from that in the embodiment. In Modification 1, everything is the same as in the embodiment except for the structure of the energized component; therefore, description is omitted. Figure 8 In the text, structural elements that are the same as those in the implementation method are marked with the same symbols.

[0061] Similar to the implementation method, for the first energized component 231A and the second energized component 232A of Modification Example 1, the movement (gripping of the molding material 103) and energization of the components are controlled by the control device 230.

[0062] The first energized component 231A has a first gripping component 231c and a second gripping component 231b, and is located on one end of the forming material 103.

[0063] The first gripping member 231c is prismatic and located on the outer periphery of the forming material 103. The first gripping member 231c has a curved surface 2312, a portion of which is bent into a concave shape on the side contacting the forming material 103. The radius of curvature of the wall forming this curved surface 2312 is preferably greater than the wire diameter of the forming material 103. Furthermore, while the surface of the first gripping member 231c in contact with the forming material 103 can have the above-described shape, other portions can also be cylindrical or other polygonal shapes.

[0064] In addition, the first gripping component 231c can move toward or away from the second gripping component 231b under the control of the control device 230.

[0065] The second energized component 232A has a first gripping component 232c and a second gripping component 232b, and is located on the other end side of the forming material 103.

[0066] The first gripping member 232c is prismatic and located on the outer periphery of the forming material 103. The first gripping member 232c has a curved surface 2322, a portion of which is bent into a concave shape on the side that contacts the forming material 103. The radius of curvature of the wall forming the curved surface 2322 is preferably greater than the wire diameter of the forming material 103.

[0067] Furthermore, the first gripping component 232c can move toward or away from the second gripping component 232b under the control of the control device 230.

[0068] Under the control of the control device 230, the energization of the first energized component 231A and the second energized component 232A is controlled via a live wire (not shown). At this time, as in the embodiment, control is performed in such a way that the contact area ratio is the same as the current ratio.

[0069] The control device 230, for example, positions the molded material 103 in a predetermined position and moves the gripping members of the first energized member 231A and the second energized member 232A, causing them to grip one end and the other end of the molded material 103 respectively. Thereafter, the control device 230 allows current to flow through the first energized member 231A and the second energized member 232A via a live wire. Current flows through the contact area between the first energized member 231A and the second energized member 232A and the molded material 103. The heat generated at this time is used to heat the molded material 103.

[0070] In this modified example 1 described above, similar to the embodiment, heating is performed by energizing the material in such a way that the ratio of the contact area of ​​the gripping member to the material is the same as the ratio of the current flowing through the gripping member. Therefore, the material as a whole can be heated to a uniform temperature. According to this modified example 1, the unevenness in the quality of the helical spring can be reduced.

[0071] Furthermore, according to this modified example 1, concave curved surfaces 2312 and 2322 are formed on the surfaces of the first gripping members 231c and 232c that contact the forming material 103, respectively, and the forming material 103 is gripped at each curved surface, thus enabling more reliable gripping of the forming material 103.

[0072] Variation Example 2 Next, refer to Figure 9 A variation of this embodiment, Example 2, will be described. Figure 9 This diagram illustrates the energized heating in Modification 2. In Modification 2, the structure of the energized component for energized heating differs from that in the embodiment. In Modification 2, everything is the same as in the embodiment except for the structure of the energized component; therefore, description is omitted. Figure 9 In the text, structural elements that are the same as those in the implementation method are marked with the same symbols.

[0073] Similar to the implementation method, for the first energized component 231B and the second energized component 232B of Modification Example 2, the movement (gripping of the molding material 103) and energization of the components are controlled by the control device 230.

[0074] The first energized component 231B has a first gripping component 231d and a second gripping component 231b, and is located on one end side of the forming material 103.

[0075] The first gripping member 231d is prismatic and located on the outer periphery of the molding material 103. The first gripping member 231d has a V-shaped groove 2313 on a portion of its surface that contacts the molding material 103. The area formed by this groove 2313 (width and depth) is configured such that the first gripping member 231d does not contact the second gripping member 231b. Furthermore, while the surface of the first gripping member 231d that contacts the molding material 103 can have the aforementioned shape, other portions can also be cylindrical or other polygonal shapes.

[0076] Furthermore, the first gripping component 231d can move toward or away from the second gripping component 231b under the control of the control device 230.

[0077] The second energized component 232B has a first gripping component 232d and a second gripping component 232b, and is located on the other end side of the forming material 103.

[0078] The first gripping member 232d is prismatic and located on the outer periphery of the forming material 103. The first gripping member 232d has a V-shaped groove 2323 on a portion of the surface that contacts the forming material 103. The forming area (forming width) of the groove 2323 is preferably larger than the wire diameter of the forming material 103.

[0079] Furthermore, the first gripping component 232d can move toward or away from the second gripping component 232b under the control of the control device 230.

[0080] Under the control of the control device 230, the energization of the first energized component 231B and the second energized component 232B is controlled via a live wire (not shown). At this time, as in the embodiment, control is performed so that the contact area ratio is the same as the current ratio. Furthermore, the contact area ratio is the sum of the area ratios of the various portions of the gripping component that contact the forming material.

[0081] The control device 230, for example, grips one end and the other end of the molding material 103 by moving the gripping members of the first energized member 231B and the second energized member 232B, which are positioned at a predetermined location. Thereafter, the control device 230 allows current to flow through the first energized member 231B and the second energized member 232B via a live wire. Current flows through the contact area between the first energized member 231B and the second energized member 232B and the molding material 103. The heat generated at this time is used to heat the molding material 103.

[0082] In this modified example 2 described above, similar to the embodiment, heating is performed by energizing the material in such a way that the ratio of the contact area of ​​the gripping member to the material is the same as the ratio of the current flowing through the gripping member. Therefore, the material as a whole can be heated to a uniform temperature. According to this modified example 2, the unevenness in the quality of the helical spring can be reduced.

[0083] Furthermore, according to this modified example 2, grooves 2313 and 2323 are formed on the surfaces of the first gripping members 231d and 232d that contact the forming material 103, respectively, so that the forming material 103 can be gripped at each curved surface, thus enabling more reliable gripping of the forming material 103.

[0084] Variation Example 3 Next, refer to Figure 10 and Figure 11 A variation of this embodiment, Example 3, will be described. Figure 10 This is a diagram used to illustrate the electric heating of modified example 3. Figure 11 yes Figure 10 The AA-line sectional view shown. Figure 10 Equivalent to from Figure 3 The diagram shown is viewed in the direction of arrow A. Additionally, Figure 11 The diagram shows a cross-sectional view with a plane parallel to the winding axis of the forming material 103 as the cut surface. In Modification 3, the structure of the energized component for heating differs from that in the embodiment. In Modification 3, except for the structure of the energized component, everything else is the same as in the embodiment, so the description is omitted.

[0085] Similar to the implementation method, for the first energized component 231C in Modification 3, the movement (gripping of the molding material 103) and energization of the component are controlled by the control device 230. Furthermore, the same structure can be used for the second energized component.

[0086] The first energized component 231C has a first gripping component and a second gripping component 231g, and is located on one end side of the forming material 103. The first gripping component has a first component 231e and a second component 231f.

[0087] The first component 231e and the second component 231f are prism-shaped and arranged side by side along the winding axis of the forming material 103, contacting the forming material 103 at the same number of turns. In this modified example 3, the first energized component 231C has multiple (in this case, two) contact portions on its outer periphery that contact the forming material at the same number of turns. These contact portions are not limited to the same number of turns; they can also be located at a slight distance from each other.

[0088] In addition, the first gripping component can move toward or away from the second gripping component 231g under the control of the control device 230.

[0089] The second gripping member 231g is cylindrical and located on the inner periphery of the molded material 103. Alternatively, the second gripping member 231g may also be polygonal.

[0090] Under the control of the control device 230, the energization of the first energized component 231C is controlled via a live wire (not shown). At this time, as in the embodiment, control is performed in such a way that the contact area to current ratio is the same. Furthermore, the contact area is the sum of the areas of the positions where the first component 231e and the second component 231f respectively contact the molding material 103.

[0091] The control device 230, for example, positions itself on the molded material 103 at a predetermined location and moves the gripping components of the first energized component 231C and the second energized component to grip one end and the other end of the molded material 103, respectively. Then, the control device 230 allows current to flow through the first energized component 231C and the second energized component via a live wire. Current flows through the contact area between the first energized component 231C and the second energized component and the molded material 103. The heat generated at this time is used to heat the molded material 103.

[0092] In this modified example 3 described above, similar to the embodiment, heating is performed by energizing the material in such a way that the ratio of the contact area of ​​the gripping member to the material is the same as the ratio of the current flowing through the gripping member. Therefore, the material as a whole can be heated to a uniform temperature. According to this modified example 3, the unevenness in the quality of the helical spring can be reduced.

[0093] Variation Example 4 Next, refer to Figure 12 A variation of this embodiment, example 4, will be described. Figure 12 This diagram illustrates the energized heating in Modification 4. In Modification 4, a water-cooling structure is provided inside the energized component of the embodiment. In Modification 4, except for the structure of the energized component, everything else is the same as in the embodiment, therefore, description is omitted. Figure 12 In the text, structural elements that are the same as those in the implementation method are marked with the same symbols.

[0094] Similar to the implementation method, for the first energized component in Modification 4, the movement (gripping of the molding material 103) and energization of the component are controlled by the control device 230. Furthermore, the same structure can be used for the second energized component.

[0095] The first energized component of this modified example 4 has a first gripping component 231h and a second gripping component 231i, and is located on one end side of the forming material 103.

[0096] The first gripping component 231h is a hollow prism and is located on the outer periphery of the forming material 103. A bottomed hollow space 2340 is formed in the first gripping component 231h. A tube 2341 is provided in the hollow space 2340. In this modified example 4, cooling water used to cool the first gripping component 231h flows from the outside into the tube 2341. Cooling water discharged outside the tube 2341 flows through the hollow space 2340 outside the tube 2341 and is sent to the outside of the first gripping component 231h.

[0097] Furthermore, the first gripping component 231h can move toward or away from the second gripping component 231i under the control of the control device 230.

[0098] The second gripping member 231i is a hollow prism and is located on the outer periphery of the forming material 103. A bottomed hollow space 2350 is formed in the second gripping member 231i. A tube 2351 is provided in the hollow space 2350. In this modified example 4, cooling water used to cool the second gripping member 231i flows from the outside into the tube 2351. Cooling water discharged outside the tube 2351 flows through the hollow space 2350 outside the tube 2351 and is sent to the outside of the second gripping member 231i.

[0099] Under the control of the control device 230, the energization of the first energized component in this modified example 4 is controlled via a live wire (not shown). At this time, as in the embodiment, control is performed in a manner that ensures the contact area to current ratio is the same.

[0100] The control device 230, for example, positions the molding material 103 at a predetermined location and moves the gripping components of the first and second energized components to grip one end and the other end of the molding material 103, respectively. Then, the control device 230 allows current to flow through the first and second energized components via a live wire. Current flows through the contact points between the first and second energized components and the molding material 103. The heat generated at this time is used to heat the molding material 103.

[0101] In this modified example 4 described above, similar to the embodiment, heating is performed by energizing the gripping member for gripping the forming material in such a way that the contact area ratio of the gripping member to the forming material is the same as the current ratio of the current flowing through the gripping member. Therefore, the forming material as a whole can be heated at a uniform temperature. According to this modified example 4, the unevenness in the quality of the helical spring can be reduced.

[0102] Furthermore, according to this modified example 4, cooling water is circulated inside the first gripping member 231h and the second gripping member 232i, thereby regulating the temperature of the heated forming material 103 and suppressing damage to the gripping members caused by heat.

[0103] The foregoing has described the methods for implementing the present invention, but the present invention should not be limited to the above embodiments. For example, the structures of the energizing components of the embodiments and modifications can be appropriately combined for the first and second energizing components that respectively grasp the ends of the molded material.

[0104] Thus, the present invention can include various embodiments not described herein, and various design changes can be made without departing from the technical concept defined by the scope of the claims. Furthermore, while the heating process during the manufacture of the helical spring has been described in the above embodiments, it can also be used, for example, for the manufacture of other spring components such as stabilizers.

[0105] Industrial applicability As explained above, the manufacturing method and control device for the spring component of the present invention are suitable for suppressing uneven quality of the spring component.

[0106] Symbol explanation: 1. Coil spring 100 base material 101 Wire Drawing Material 102 and 103 forming materials 200 winding machine 210, 230 control devices 211, 231, 231A~231C First energized component 212, 232, 232A, 232B Second energized components 221 slots 222 Water-soluble quenching agent 231a, 231c, 231d, 232a, 232c, 232d, 231h First gripping component 231b, 231g, 232b, 231i Second gripping components 231e First Component 231f Second Component 2311, 2321 Planar section 2312, 2322 Curved surfaces 2313, 2323 grooves Hollow spaces at 2340 and 2350 Pipes 2341 and 2351.

Claims

1. A method for manufacturing a spring component, comprising a method for manufacturing a spring component obtained by processing a base material formed from wire, characterized in that, include: The cold forming process involves cold forming the base material to produce a spiral-shaped profile. The quenching process involves quenching the formed material. and The tempering process involves tempering the quenched formed material. During heating in at least one of the quenching and tempering processes, With both ends of the molded material held by the first and second energizing components, the molded material is electrically heated by energizing the first and second energizing components. The first energizing component clamps and holds one end of the molded material using a set of gripping components, and the second energizing component clamps and holds the other end of the molded material using a set of gripping components. In each energized component, the current ratio R2 is set to a value near the contact area ratio R1, which includes the contact area ratio R1, for energizing. The current ratio R2 is the ratio of the current flowing through a gripping component to the sum of the currents flowing through the energized component. The contact area ratio R1 is the ratio of the contact area between the gripping component and the forming material to the sum of the contact areas of each contact area between the forming material and the gripping component in the energized component.

2. The method for manufacturing a spring component according to claim 1, characterized in that, The current ratio R2 is set within the range of the contact area ratio R1 ± 0.1 when energizing.

3. The method for manufacturing a spring component according to claim 1, characterized in that, The cooling water circulates inside the electrically powered component.

4. A control device for controlling the manufacture of a spring component, the manufacture of the spring component comprising: The cold forming process involves cold forming a base material made of wire to create a spiral-shaped profile. The quenching process involves quenching the formed material. and The tempering process involves tempering the quenched formed material. The control device is characterized in that... During heating in at least one of the quenching and tempering processes, With both ends of the molded material held by the first and second energizing components, electricity is supplied to the first and second energizing components. The first energizing component clamps and holds one end of the molded material using a set of gripping components, and the second energizing component clamps and holds the other end of the molded material using a set of gripping components. In each energized component, the current ratio R2 is set to a value near the contact area ratio R1, which includes the contact area ratio R1. The current ratio R2 is the ratio of the current flowing through a gripping component relative to the sum of the currents flowing through the energized component, and the contact area ratio R1 is the ratio of the contact area between the gripping component and the forming material relative to the sum of the contact areas of the forming material and the gripping component in the energized component.

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