JP2014231069A - Manufacturing apparatus of arc-shaped coil spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing apparatus of an arc-shaped coil spring whose entire body consists of uniform radius of curvature and in which work efficiency is improved to achieve cost reduction.SOLUTION: A manufacturing apparatus of an arc-shaped coil spring comprises: a semi-cylindrical fixed receiving metal fitting 2 which holds linear coil springs W in the state where the springs are bridged over an inner peripheral surface 2a; a pair of cylindrical movable pressing metal fittings 3a, 3b which are parallelly provided along an axis line horizontally above the inner peripheral surface 2a and curve the coil springs W; a pair of movable walls 4 which is inserted and fitted into the fixed receiving metal fitting 2 freely movably forward and backward and contacts both end surfaces of the coil springs W; a pair of fixed plates 7 extending in an axial direction along an outer wall 2b of the fixed receiving metal fitting 2; and a plurality of fixing bolts 8a to 8d screwed into the fixed plates. The fixed plate 7 is positioned and fixed by the fixing bolts 8a, 8d on end portion sides, and the fixing bolts 8b, 8c in the central part contact the movable walls 4, the walls are pushed toward the fixed receiving metal fitting 2 side and protruded from the inner peripheral surface 2a, and end portions of the coil spring W are further curved.

Description

  The present invention relates to an apparatus for manufacturing an arc-shaped coil spring used for a portion of a clutch disk or the like that is bent in the circumferential direction.

  For example, a spring type clutch disk transmits torque by a coil spring mounted between the hub and the disk, and performs a buffering action when the clutch is engaged and a vibration preventing action in a power transmission system. As shown in FIG. 7, the coil springs of this spring type clutch disk are fitted into arc-shaped spring grooves 52 formed in a plurality (six in the illustrated example) along the circumferential direction of the clutch disk 51. The

  Since the coil spring 53 in the free state before being fitted into the spring groove 52 is linear, if the linear coil spring 53 is fitted into the arc-shaped spring groove 52 as it is, the outer periphery of the coil spring 53 is A strong frictional resistance is generated between the surface and the inner wall surface of the spring groove 52, particularly at point A. This frictional resistance increases as the diameter of the clutch disk 51 decreases, that is, as the radius of curvature of the arc-shaped spring groove 52 decreases. Depending on the magnitude of the frictional resistance, the outer surface of the coil spring 53 and the spring of the clutch disk 51 are increased. The inner wall surface of the groove 52 may be damaged, and the function of the coil spring 53 may be reduced.

  For this reason, it is known to reduce the frictional resistance by making the coil spring 53 into a so-called arc spring. As a conventional method of forming an arc spring, a manufacturing method as shown in FIG. 8A is known.

  This arc-shaped coil spring manufacturing method is performed at a temperature of about 350 ° C. to 450 ° C. in a state where the spring is curved by inserting an arc-shaped cored bar 54 on the inner diameter side of the coil spring 53. An arc-shaped coil spring having a certain radius of curvature is formed by applying a so-called creep temper for a low temperature annealing process of 60 minutes to 60 minutes (see, for example, Patent Document 1).

JP 2007-268573 A

  However, in this conventional manufacturing method, it is necessary to insert one arc-shaped cored bar 54 on the inner diameter side of the linear coil spring 53, and the core corresponds to the radius of curvature of the arc-shaped coil spring. Since it is necessary to prepare each of the gold | metal | money 54, the operation | work became complicated and not only the work efficiency worsened, but there existed a problem that the management cost of the metal core 54 increased and the manufacturing cost was caused.

  Further, as shown in FIG. 8B, in the arc-shaped coil spring 55 manufactured by such a method, the radius of curvature of the end portion becomes larger than that of other portions, and there is a possibility that the entire portion may not be smoothly curved. is there. In this case, as shown in FIG. 7, excessive friction is generated between the inner surface of the spring groove 52 of the clutch disk 51, and it may be difficult to obtain a stable torque.

  An object of the present invention is to provide an apparatus for manufacturing an arc coil spring having a uniform curvature radius, which can freely cope with various curvature radii, improve work efficiency, reduce costs, and has a uniform curvature radius as a whole. .

  In order to achieve such an object, the invention according to claim 1 of the present invention is configured such that a linear coil spring is held in a curved state and subjected to a low-temperature annealing treatment at a predetermined temperature and time, thereby providing a constant radius of curvature. In a manufacturing apparatus for forming an arc-shaped coil spring having an inner peripheral surface formed with a radius of curvature corresponding to the arc-shaped coil spring, the linear coil spring is straddled on the inner peripheral surface. A semi-cylindrical fixed receiving metal fitting to be held, and a cylindrical movable pressing metal fitting that has an outer peripheral surface having a smaller radius of curvature than an inner peripheral surface of the fixed receiving metal fitting, and presses and curls the coil spring; The movable pressing metal fitting is inserted into a through hole formed in the fixed receiving metal fitting so as to be able to advance and retreat. A pair of movable walls that abut against the end face and position-regulate, a pair of fixed plates that extend in the axial direction along the outer wall of the fixed bracket, and a plurality of fixed bolts that are screwed along the longitudinal direction of the fixed plate And a fixing bolt on the end side of the fixing plate among the plurality of fixing bolts is screwed to the fixing bracket to position and fix the fixing plate, and the fixing bolt of the plurality of fixing bolts is fixed. A fixed bolt at the center of the plate is in contact with the movable wall, and the movable wall is protruded from the inner peripheral surface of the fixed bracket by pushing the fixed bolt at the center toward the fixed bracket. Further curl the end of the spring.

  Thus, in a manufacturing apparatus for forming an arc-shaped coil spring having a constant radius of curvature by holding a linear coil spring in a curved state and performing low-temperature annealing treatment at a predetermined temperature and time, an arc-shaped coil A semi-cylindrical fixed bracket having an inner circumferential surface formed with a radius of curvature corresponding to the spring and holding a linear coil spring straddling the inner circumferential surface; A cylindrical movable pressing metal fitting that has an outer circumferential surface with a smaller radius of curvature than the peripheral surface and that presses and curls the coil spring, a drive unit that presses the movable pressing metal piece toward the coil spring, and a fixed Along the outer wall of the fixed bracket and a pair of movable walls that are slidably inserted into the through holes formed in the bracket, abutting against both end faces of the coil springs to regulate the position A pair of fixing plates extending in the axial direction and a plurality of fixing bolts screwed along the longitudinal direction of the fixing plate, and the fixing bolts on the end side of the fixing plate among the plurality of fixing bolts are fixed The fixing plate is screwed to the receiving metal to position and fix the fixing plate. Among the plurality of fixing bolts, the fixing bolt at the center of the fixing plate is brought into contact with the movable wall, and the fixing bolt at the center is pushed into the fixing receiving metal. As a result, the movable wall protrudes from the inner peripheral surface of the fixed bracket, and the end of the coil spring is further curved, so that the radius of curvature of the end of the arc-shaped coil spring after completion is larger than that of other parts. The characteristics can be eliminated, the working efficiency can be improved, the cost can be reduced, and an arc-shaped coil spring having a uniform curvature radius can be provided.

  Preferably, as in the invention described in claim 2, one end surface of the movable wall is formed as a concave surface along the shape of the inner peripheral surface of the fixed bracket, and the other end surface and the fixed bolt are If the tip is concavo-convex, the centering function is demonstrated by the engagement of the fixed bolt consisting of the concavo-convex surface and the movable wall, and even if the fixed bolt is pressed in an eccentric state, the movable wall against the fixed bracket Can move forward and backward smoothly.

  According to a third aspect of the present invention, the movable pressing metal fittings are configured as a pair, and are arranged in parallel horizontally along the axis of the fixed receiving metal fitting above the inner peripheral surface of the fixed receiving metal fitting. If so, the concentration of pressure on the center of the workpiece W can be alleviated, and a smooth curve can be formed on the entire workpiece W.

  According to a fourth aspect of the present invention, brackets are fixed to both end faces of the movable pressing metal fitting, and pins are erected on the end face side of the fixed receiving metal fitting of the bracket. A lock arm is fixed to the end surface, and a recess for locking the pin is formed at a predetermined position in the longitudinal direction of the lock arm, and the distance between the movable pressing metal fitting and the fixed receiving metal fitting is maintained by the lock arm. If this is the case, the distance between the fixed receiving bracket and the movable pressing bracket can be held accurately and stably, and the imbalance between both end faces of the movable pressing bracket during processing can be eliminated, and the workpiece can be curved with high accuracy. Can be made.

  An apparatus for producing an arc coil spring according to the present invention holds an arc coil spring having a constant radius of curvature by holding the linear coil spring in a curved state and performing low temperature annealing treatment at a predetermined temperature and time. In the manufacturing apparatus for molding, a semi-cylindrical shape having an inner peripheral surface formed with a radius of curvature corresponding to the arc-shaped coil spring, and holding the linear coil spring in a state straddling the linear coil spring on the inner peripheral surface. A fixed receiving metal fitting, a cylindrical movable pressing metal fitting having an outer peripheral surface having a radius of curvature smaller than the curvature radius of the inner peripheral surface of the fixed receiving metal fitting, and pressing and curving the coil spring; and the movable pressing metal fitting A drive portion that presses against the coil spring, and a both-end surface of the coil spring that is slidably fitted into a through hole formed in the fixed bracket. A pair of movable walls that abut and regulate the position; a pair of fixed plates that extend in the axial direction along the outer wall of the fixed bracket; and a plurality of fixed bolts that are screwed along the longitudinal direction of the fixed plate; Among the plurality of fixing bolts, a fixing bolt on the end side of the fixing plate is screwed to the fixing bracket to position and fix the fixing plate, and among the plurality of fixing bolts, the fixing plate A fixed bolt at the center is brought into contact with the movable wall, and the movable wall is caused to protrude from the inner peripheral surface of the fixed bracket by pushing the fixed bolt at the center toward the fixed bracket. Since the end part is further curved, the characteristic that the radius of curvature of the end part of the arc coil spring after completion becomes larger than other parts can be eliminated, and the work efficiency is improved. Achieving cost reduction, it is possible to provide an arc-shaped coil springs made entirely of uniform radius of curvature.

It is a disassembled perspective view which shows one Embodiment of the manufacturing apparatus of the arc-shaped coil spring which concerns on this invention. It is a top view of the manufacturing apparatus of the arc-shaped coil spring of FIG. (A) is a front view of the manufacturing apparatus of the arc-shaped coil spring of FIG. 1, (b) is a side view of (a), and (c) is a cross-sectional view taken along line III-III of FIG. is there. It is a front view which shows the positioning mechanism of the movable press metal fitting which concerns on this invention. (A) is explanatory drawing which shows the state by which the lock arm was fixed to the pin of a movable press metal fitting, (b) is a principal part enlarged view which shows the fixing | fixed part of the lock arm of (a). (A)-(d) is explanatory drawing which shows the manufacturing process of the arc-shaped coil spring which concerns on this invention. It is a front view which shows the conventional clutch disk. (A) is explanatory drawing which shows the manufacturing method of the conventional arc-shaped coil spring, (b) is a front view which shows the arc-shaped coil spring manufactured by (a).

  A linear coil spring is held in a curved state and is subjected to low temperature annealing treatment at a predetermined temperature and time, thereby producing an arc coil spring having a constant radius of curvature. A semi-cylindrical fixed receiving bracket that has an inner peripheral surface formed at a radius of curvature and that holds the linear coil spring across the inner peripheral surface, and an inner peripheral surface of the fixed receiving bracket An outer peripheral surface having a smaller radius of curvature than the inner peripheral surface of the fixed receiving bracket, and arranged horizontally along the axis of the fixed receiving bracket, in contact with the coil spring. A pair of cylindrical movable pressing fittings to be bent, a drive unit that presses the movable pressing fittings toward the coil spring, and a through-hole formed in the fixed receiving bracket so as to freely advance and retract. A pair of movable walls inserted and abutted against both end faces of the coil spring to regulate the position, a pair of fixed plates extending in the axial direction along the outer wall of the fixed bracket, and along the longitudinal direction of the fixed plate A plurality of fixing bolts to be screwed together, and among the plurality of fixing bolts, a fixing bolt on an end portion side of the fixing plate is screwed to the fixing receiving bracket to position and fix the fixing plate, and Among the plurality of fixing bolts, a fixing bolt at the center of the fixing plate is brought into contact with the movable wall, and the movable wall is moved into the inner side of the fixed receiving metal by pushing the fixing bolt at the center toward the fixed receiving metal. Projecting from the peripheral surface, the end of the coil spring is further curved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view showing an embodiment of an arc-shaped coil spring manufacturing apparatus according to the present invention, FIG. 2 is a plan view of the arc-shaped coil spring manufacturing apparatus of FIG. 1, and FIG. 1 is a front view of the arc-shaped coil spring manufacturing apparatus of FIG. 1, (b) is a side view of (a), (c) is a cross-sectional view taken along line III-III of FIG. 2, and FIG. The front view which shows the positioning mechanism of the movable press metal fitting which concerns on invention, FIG. 5 (a) is explanatory drawing which shows the state by which the lock arm was fixed to the pin of a movable press metal fitting, (b) is the lock arm of (a). FIG. 6A to FIG. 6D are explanatory views showing the manufacturing process of the arc-shaped coil spring according to the present invention.

  FIG. 1 shows an arc coil spring manufacturing apparatus according to the present invention. The manufacturing apparatus includes a semi-cylindrical fixed receiving metal fitting 2 that is fixed to a base 1 and holds a linear coil spring (hereinafter referred to as a workpiece) W, and an air cylinder (not shown) that serves as a drive unit. The pressure body 3 that moves forward and backward in the fixed bracket 2 as the (or foot press) moves up and down is the main configuration.

  The fixed bracket 2 has a substantially semicircular cross section, is formed in a semi-cylindrical shape obtained by cutting a cylindrical pipe in the axial direction, and a bottom portion thereof is integrally fixed to the base 1. The inner peripheral surface 2a of the fixed bracket 2 is formed to have a radius of curvature smaller than the radius of curvature of an arc-shaped coil spring, which will be described later, and a plurality of workpieces W (here, three pieces) are provided above the inner peripheral surface 2a. ) Arranged. In addition, a pair of movable walls 4, 4 that are in contact with both end surfaces of the workpiece W and regulate the position are fitted and inserted into the fixed bracket 2 so as to freely advance and retract.

  The pressure body 3 includes a pair of cylindrical movable pressing fittings 3a and 3b. The pressure body 3 is arranged in parallel horizontally along the axis of the stationary receiving bracket 2 above the inner peripheral surface 2a of the stationary receiving bracket 2. The both end surfaces are fixed to 5,5. As shown in FIG. 3B, the bracket 5 is formed in an inverted L-shaped cross section, and a pin 6 is erected at a substantially central portion of the end surface 5 a that protrudes toward the end surface side of the fixed bracket 2. .

  As shown in FIGS. 2 and 3A, a pair of fixing plates 7, 7 extending in the axial direction along the outer wall 2 b of the fixed bracket 2 is provided. A plurality of fixing bolts 8a to 8d (four in this case) are screwed in the longitudinal direction of the fixing plate 7, and among the plurality of fixing bolts 8a to 8d, the fixing bolts 8a and 8d on the end side are fixed receivers. The fixing plate 7 is positioned and fixed to the fixed receiving metal fitting 2 by being screwed to the metal fitting 2. On the other hand, of the plurality of fixing bolts 8a to 8d, the remaining central fixing bolts 8b and 8c are brought into contact with movable walls 4 and 4 to be described later, and an operating portion for moving the movable walls 4 and 4 forward and backward with respect to the fixed bracket 2. To work.

  The movable wall 4 is formed in a plate shape extending along the axis of the fixed receiving metal fitting 2 and is fitted in a rectangular through hole 2c formed in the fixed receiving metal fitting 2 so as to freely advance and retract. As shown in FIG. 3C, the movable wall 4 is formed such that one end surface 4a is a concave surface along the shape of the inner peripheral surface 2a of the fixed bracket 2 and the other end surface 4b is a bowl-shaped convex surface. Is formed. And the fixing bolts 8b and 8c by which the front-end | tip was formed in the concave surface of circular arc shape are contact | abutted so that it may fit in the end surface 4b which consists of this convex surface. The centering function is exhibited by the engagement of the fixed bolts 8b and 8c having such uneven surfaces and the movable wall 4, and even if the fixed bolts 8b and 8c are pressed in an eccentric state, the movable wall 4 is pressed against the fixed bracket 2. 4 can move forward and backward smoothly. In addition, the end surface 4b of the movable wall 4 may be formed as a concave surface, and the fixing bolts 8b and 8c may be formed into a convex surface so that the both sides can be concavo-convexly fitted.

  FIG. 4 shows a positioning mechanism for the movable pressing fittings 3a and 3b according to the present invention. Lock arms 9 are swingably attached to both end faces of the fixed bracket 2 via a pivot 10. The lock arm 9 is formed with a recess 11 for locking to the pin 6 of the bracket 5. As shown in an enlarged view in FIG. 5 (b), the recess 11 has a rectangular insertion groove 11a set slightly larger than the outer diameter of the pin 6, and an arcuate shape in one of the insertion grooves 11a. A concave groove 11b is formed. The concave groove 11b is formed on the distal end side of the lock arm 9 in the longitudinal direction. As described above, the bracket 5 is fixed to both end faces of the movable pressing fittings 3a and 3b, and the pins 6 for locking the lock arm 9 are provided on these brackets 5, respectively. The distance between the metal fittings 3a and 3b can be held accurately and stably, the imbalance between both end faces of the movable pressing metal fittings 3a and 3b being processed can be eliminated, and the workpiece W can be accurately curved. it can.

Next, a method for manufacturing an arc coil spring will be described with reference to FIGS.
As shown to (a), the workpiece | work W is straddled on the upper direction of the internal peripheral surface 2a of the fixed metal fitting 2 in the state aligned. Thereafter, as shown in (b), the pressure body 3 is lowered as the air cylinder (not shown) is lowered, and presses the workpiece W toward the bottom (in the direction of the arrow) of the fixed bracket 2. Then, as shown in FIG. 5A, the work W is elastically deformed to a desired radius of curvature, that is, the air cylinder 12 is stopped at the bottom dead center. The stroke amount of the air cylinder 12 at this time is L + α. Thereafter, the lock arm 9 is swung, and the insertion groove 11 a of the recess 11 is engaged with the pin 6 of the bracket 5.

  Here, as shown in FIG. 5 (b), a nut-like head 6a is screwed onto the tip of the pin 6 so that the lock arm 9 is not loosened or detached from the pin 6 during processing. The portion 6a is fastened to the pin 6, and the lock arm 9 is fixed to the pin 6 without play. Note that the distance (gap) between the outer diameter of the pin 6 and the groove 11b of the recess 11 is set to α. Here, in consideration of workability and workability, the distance α is set to 2 to 3 mm.

  Next, when the air cylinder 12 is released and raised to the top dead center, the pressure body 3 slightly rises by α due to the repulsive force of the workpiece W, and the pin 6 is locked in the concave groove 11b of the lock arm 9 without gaps. Is done. This state is shown in FIG. As described above, since the concave groove 11b is provided in the recess 11 of the lock arm 9 to lock the pin 6, it is possible to prevent loosening during processing and to improve processing efficiency during mass production. it can.

  Thereafter, the fixing bolts 8b and 8c are pushed into the fixed receiving metal fitting 2 side (indicated by arrows) to cause the movable wall 4 to protrude from the inner peripheral surface 2a of the fixed receiving metal fitting 2, and only the end portion of the workpiece W is further curved. . By such a series of operations, it is possible to eliminate the characteristic that the radius of curvature of the end portion of the workpiece W after completion is larger than that of other portions, improve the work efficiency and reduce the cost. An arc coil spring having a uniform radius of curvature can be provided.

  Note that the fixed bolts 8b and 8c and the movable wall 4 contacting the end of the workpiece W are always in contact with a predetermined contact pressure due to the repulsive force of the workpiece W, so the fixed bolts 8b and 8c are in any position. Even if it exists, backlash does not arise in the movable wall 4, but the movable wall 4 can be advanced / retreated with high precision following the movement of the fixing bolts 8b, 8c.

  In the state shown in FIG. 6C, that is, in a state in which the workpiece W is positioned and fixed, the process proceeds to a heat treatment step described later by a conveyor (not shown). After this heat treatment, the lock arm 9 is swung and released from the pin 6. Thereafter, as shown in FIG. 6 (d), the air cylinder (not shown) is raised and the fixing bolts 8 b and 8 c are returned to their original positions, whereby the end surface 4 a of the movable wall 4 is fixed to the inner peripheral surface of the fixed bracket 2. In accordance with 2a, the workpiece W is released from the pressure body 3 and can be easily taken out. By adopting such a manufacturing apparatus, it is no longer necessary to prepare cored bars corresponding to the radius of curvature of the arc-shaped coil spring as in the prior art, and it is possible to freely correspond to the radius of curvature of various arc-shaped coil springs. In addition, it is possible to provide an arc coil spring having a uniform curvature radius as a whole.

  Further, as in the present embodiment, the pressure body 3 is composed of a pair of cylindrical movable pressing fittings 3a and 3b, so that the pressure concentration on the center of the workpiece W is alleviated and the entire workpiece W is smoothly curved. Can be formed.

  Here, the curvature radius of the workpiece W is managed by the stroke amount of the pressure body 3, but besides this, for example, although not shown, the pressure body is constituted by a single cylindrical movable pressing metal fitting, Set the radius of curvature of the inner surface of the fixed bracket to approximately the same as the radius of curvature of the workpiece (the arc coil spring after completion), and set the radius of curvature of the movable pressing bracket to be smaller than the radius of curvature of the fixed bracket. The curvature radius of the workpiece may be managed by lowering the pressure body until there is no gap between the workpiece and the inner peripheral surface of the fixed bracket. The abbreviation “substantially the same” as used herein means, for example, a design target value that is substantially free from a diameter difference, that is, a diameter difference caused by a processing error or the like should be allowed. .

  Next, post-processes such as a heat treatment process for the workpiece W will be described. As shown in FIG. 6 (c), after the compression processing of the workpiece W is completed, the pressure body 3 and the fixed receiving metal fitting 2 are positioned and fixed by a lock arm (not shown) and are moved by the conveyor in the atmosphere furnace. The The atmosphere furnace is set to a total length of 2.0 to 3.0 m, and the workpiece W is heated over 25 to 30 minutes. The temperature condition at this time is appropriately set depending on the material of the workpiece W. For example, when the workpiece W is formed of a spring piano wire, the temperature condition is in the range of 200 to 300 ° C., and the stainless steel wire or oil When it is formed of a tempered wire, it is set in the range of 300 to 420 ° C. That is, it is preferable to set the same temperature condition as when the arc-shaped coil spring is molded.

  In addition, if necessary, shot peening can be performed before or after arc coil spring molding to improve sag resistance and fatigue resistance, and to increase surface hardness and wear resistance. Can be improved. Further, after the shot peening process, a process such as compression setting may be performed at room temperature or warm in order to prevent the arc-shaped coil spring from sagging.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The arc-shaped coil spring manufacturing apparatus according to the present invention, after forming a spring wire into a linear coil spring by coiling, holds it in a mold and holds it in a circular arc shape with a compressive load applied thereto. It can be applied to a manufacturing apparatus that performs low-temperature annealing.

DESCRIPTION OF SYMBOLS 1 Base 2 Fixed receiving metal fitting 2a Inner peripheral surface 2b of fixed receiving metal fitting Outer wall 2c Through hole 3 Pressure body 3a, 3b Movable pressing metal piece 4 Movable wall 4a, 4b End face 5 of movable wall Bracket 5a End face 6 of bracket Pin 6a Pin head 7 Fixing plate 8a-8d Fixing bolt 9 Lock arm 10 Pivot 11 Recess 11a Insertion groove 11b Recess groove 12 Air cylinder 51 Clutch disc 52 Spring groove 53, 55 Coil spring 54 Core metal L Stroke of air cylinder Amount W Work α Distance between pin outer diameter and recess groove

Claims (4)

In a manufacturing apparatus for forming an arc-shaped coil spring having a constant radius of curvature by holding a linear coil spring in a curved state and performing low-temperature annealing treatment at a predetermined temperature and time,
A semi-cylindrical fixed bracket having an inner peripheral surface formed with a radius of curvature corresponding to the arc-shaped coil spring, and holding the linear coil spring in a state straddling the inner peripheral surface;
A cylindrical movable pressing metal fitting having an outer peripheral surface having a radius of curvature smaller than the radius of curvature of the inner peripheral surface of the fixed receiving metal fitting, and pressing and curving the coil spring;
A drive unit that presses the movable pressing fitting toward the coil spring;
A pair of movable walls that are inserted into a through-hole formed in the fixed receiving metal fitting so as to freely advance and retract, and abut against both end surfaces of the coil spring to regulate the position;
A pair of fixed plates extending in the axial direction along the outer wall of the fixed bracket;
A plurality of fixing bolts screwed along the longitudinal direction of the fixing plate,
Among the plurality of fixing bolts, a fixing bolt on the end portion side of the fixing plate is screwed to the fixing bracket to position and fix the fixing plate,
Among the plurality of fixing bolts, a fixing bolt at a center portion of the fixing plate is brought into contact with the movable wall, and the fixing wall at the center portion is pushed into the fixing bracket, thereby moving the movable wall to the fixed bracket. An apparatus for manufacturing an arc-shaped coil spring characterized by protruding from an inner peripheral surface and further bending the end of the coil spring.   The one end surface of the movable wall is formed as a concave surface along the shape of the inner peripheral surface of the fixed receiving metal fitting, and the other end surface and the tip of the fixing bolt are unevenly fitted. Arc coil spring manufacturing equipment.   3. The arc-shaped coil according to claim 1, wherein the movable pressing metal fittings are configured as a pair, and are arranged in parallel horizontally along the axis of the fixed metal fittings above the inner peripheral surface of the fixed metal fittings. Spring manufacturing equipment.   Brackets are fixed to both end faces of the movable pressing metal fitting, pins are erected on the end face side of the fixed receiving metal fitting of the bracket, and a lock arm is fixed to the end face of the fixed receiving metal fitting. The arc shape according to any one of claims 1 to 3, wherein a recess for engaging with the pin is formed at a predetermined position in a direction, and the distance between the movable pressing metal fitting and the fixed receiving metal fitting is held by the lock arm. Coil spring manufacturing equipment.

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