JPS62130730A - Forming method for zigzag spring - Google Patents

Abstract

PURPOSE:To easily form a zigzag spring by bending working by bending only, and to execute easily an adjustment of a design and a device, by forming a fish mouth by bending a torque bar part. CONSTITUTION:A cutting wire lever 6 for zigzag spring of a prescribed length is obtained by cutting a long steel iron wire of a raw material to a prescribed size. Subsequently, the center of the wire lever 6 is supported by a supporting part 7, and both the right and left ends are inserted and held simultaneously by right and left inserting and holding pieces 9, 9 of a fixed supporting body 8 of a bending device 14, and a roller 11 and 12 of a bending part 10. Next, when the bending part 10 is rotated by 90 deg., a torque bar part 3 which has been bent by 90 deg. is obtained. Thereafter, the next bending part is inserted and hold by the rollers 11, 12, the next inserting and holding part C point is inserted and held by the right and left inserting and holding pieces 9 and the bending part 10 is rotated by 90 deg., by which a loop part 2 is obtained. Subsequently, the bending part 10 is rotated and bent in the direction (a), but in this case, when the wire lever 6 is rotated in advance by 45 deg. or so in the direction (b), that which has twisted the loop part 2 and the torque bar part 3 by 45 deg. is obtained, and a fish mouth part is formed.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for forming a zigzag spring.

(Prior art) A zigzag spring A (FIG. 2) in which a loop part B and a torque bar part E are continuously formed has a fish mouth part F formed at the end of the zigzag spring A (Fig. 2). The loop portion B near both ends of is held between the twist jaw C and the fixed jaw D from both sides, and the twist jaw C is rotated to a predetermined angle around the torque bar portion E, and the third
It was formed by twisting the torque bar portion E shown in the figure.

(Problems to be Solved by the Invention) The known method of forming a fish mouth by twisting the torque bar portion E is such that the amount of springback due to the twisting process is 0.
is the bending angle α, the length of the torque bar part, and the zigzag spring A
Since the springback amount θ varies considerably depending on the wire diameter d, it is necessary to experimentally estimate and set the springback amount θ each time the wire diameter d changes.

(Means for Solving the Problem) Therefore, the present invention provides a torque 1 regardless of the method of twisting the torque bar portion E to form a fish mouth.
This method involves bending a part E of the spring to form a fish mouth, and includes a first step of cutting the steel wire 13 into a predetermined size using a cutting device to obtain a cutting wire rod 6 for a zigzag spring of a certain length; A second step in which the center portion of the rod 6 is supported by the support portion 7 and both left and right ends are simultaneously bent at right angles by the bending device 14 to form the torque bar portion 3, and the bending device 14 is moved inward by a certain width. After the movement, the wire rod 6 is bent at a right angle by the device 14 to form the loop portion 2.
The first step is to move the bending device 14 inward by a certain width, rotate the wire rod 6 a little around the axis, and then bend it at right angles by the device 14 to form the torque bar portion 3. This is a method for forming a zigzag spring obtained by repeating four strokes a desired number of times.

(Example) A long steel wire as a raw material is cut into a predetermined size T using a cutting device to obtain six groups of cutting wire rods for zigzag springs of a certain length (
Figure 6).

Next, as shown in FIG. 7, the center of the wire rod 6 is supported by the support part 7.

Next, the left and right outer ends of the wire rod 6 whose center part is supported by the support part 7 are simultaneously bent by the left and right holding pieces 9 and 9 of the fixed support body 8 of the bending device 14.
and the roller U and the roller 12 of the bent portion 10. That is, if a is the outer end of the wire rod 6, b is the bent part, and C is the clamping part, the bent part is clamped by the rollers 11.12, and the clamping part C is clamped by the left and right clamping pieces 9.9. Figure 8)
.

Next, when the bending part 10 is rotated by 90 degrees in the A direction, a torque bar part 3 which is bent by 90 degrees from the point of the bending part is obtained (FIG. 9).

Next, the bent portion lO is returned to its original position, the bent portion gi14 is moved inward by a predetermined dimension, and the next bent point is set by the roller 11,
The loop portion 2 is obtained by holding the next holding portion C between the left and right holding pieces 9 (Fig. 1θ) and rotating the bent portion 10 by 90” as shown in Fig. 11.

In this case, the torque bar part 3 and the loop part 2 become L-shaped, and then the bending device 14 of a predetermined dimension is moved inward, and the bending part 10 is rotated again in the A direction to bend it. If the wire rod 6 is rotated about 45 degrees toward the mouth as shown in Figure 13, the loop part 2 and torque bar part 3 will be twisted by 45 degrees, so combine these strokes. Then, what is shown in FIG. 1 can be easily obtained, and the fish mouth portion 4 can be formed.

Also, the bending part! By changing the amount of rotation of 0 and the amount of rotation of the wire rod 6 in the direction around the axis, the length of each torque bar portion 3 and loop portion 2 can be changed, and fish mouth portions 4 of various shapes can be formed. can do.

(Effects) As described above, a conventional zigzag spring A (FIG. 2) in which a loop portion B and a torque bar portion E are continuously formed has a fishmouth portion F formed at the end thereof, but this known spring The loop part B near both ends of the zigzag spring A is held between the twist jaw C and the fixed jaw D from both sides, and the twist jaw C is rotated to a predetermined angle around the torque bar part E, and the torque bar part E in FIG. It was formed by twisting. In the known method of twisting the torque bar portion E to form a fish mouth, the springback amount O due to the twisting process is determined by the bending angle α, the length of the torque bar portion,
Since it varies considerably depending on the wire diameter d of the zigzag spring A, the spring/heck amount 0 had to be estimated and set experimentally each time these changed.

However, the present invention includes a first step in which the steel wire 13 is cut into a predetermined size by a cutting device to obtain a zigzag cutting wire rod 6 of a certain length, and a center portion of the wire rod 6 is cut by a support portion 7. A second step in which the left and right ends are simultaneously bent at right angles by the bending device 14 to form a portion 3 into the torque; and after the bending device 14 is moved inward by a certain width, the bending device 14 A third step in which the wire rod 6 is bent at right angles to form the loop portion 2, and the bending device 14 is subsequently moved inward by a certain width to slightly rotate the wire rod 6 in the direction around the axis. This is a method of forming a zigzag spring obtained by repeating the fourth step of forming the torque bar part 3 at right angles by the device 14 for a desired number of times. However, in the present invention, the straight wire rod 6 can be easily bent by simply bending it. The zigzag spring 1 can be formed into a zigzag spring 1, making it very easy to design and adjust the device.

As mentioned above, in the known example, the strength was low because the torque bar part E was twisted, but in the present invention, it can be formed by two-dimensional bending, so the zigzag spring I has high durability.

C. By changing the amount of rotation of the bending portion 10 and the amount of rotation of the wire rod 6 in the direction around the axis, fish mouth portions 4 of various shapes can be formed very easily.

This effect is achieved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a zigzag spring manufactured by the method of the present application, FIG. 2 is a perspective view of a zigzag spring manufactured by a known method, FIG. 3 is a processing state diagram of the known example, and FIG. 4 is a perspective view of a zigzag spring. 5 is a diagram showing a state in which springback amount is 0, and FIGS. 6 to 13 are diagrams showing processing states of the present invention. Explanation of symbols l...Zigzag spring, 2...Loop part, 3...Torque bar part, 4...Fish mouth part, 5...Crown part, 6...Wire rod, 7...Support part, 8... fixed support body, 9... left and right holding pieces, 10... bending part,
11...Roller, 12...Roller, 13...
Steel wire, 14...Bending device, a...Outer end, b...
- Bent part, C... clamping part.

Claims (1)

[Claims] A first step in which the steel wire 13 is cut to a predetermined size by a cutting device to obtain a cutting wire rod 6 for a zigzag spring of a certain length, and a center portion of the wire rod 6 is supported by a support portion 7 and both left and right ends are simultaneously folded. a second step in which the bending device 14 is used to bend the wire rod 6 at a right angle to form the torque bar portion 3; and after the bending device 14 is moved inward by a certain width, the wire rod 6 is bent at a right angle by the device 14; a third step in which the bending device 14 is moved inward by a certain width, the wire rod 6 is slightly rotated around the axis, and then bent at a right angle by the device 14; A method for forming a zigzag spring in which the fourth step of forming the torque bar portion 3 is repeated a desired number of times.