JP2736714B2 - Spring forming method incorporating hook end cutting step in the middle of one step - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a case when the ratio is small or torsion springs or tension the beginning end of the hook of the spring with the hook bend diameter and wire diameter of the torsion spring or tension spring begins bend not linear A spring forming method.

[0002]

2. Description of the Related Art Conventionally, a tension spring with a hook has been formed by a forming method and a forming apparatus known from, for example, Japanese Patent Publication No. 62-22698.

[0003]

In a spring with a hook as shown in FIG. 6, the bending diameter D of the hook and the diameter d of the wire are different.
In the case where the ratio / d is small and approximately 3.3 or less and the dimension A in FIG. 6 is short, the straight portion necessary to bend the hook is protruded longer than the dimension A, and after a tension spring is formed, a manual process is performed in another process. Each jig was fitted to a jig and cut into A dimensions. For this reason, the production efficiency has not been improved, labor has been required, and there has been a problem in safety management. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and the purpose is to automatically increase the length of the hook during the molding process without requiring any manpower for cutting. An object of the present invention is to provide a spring forming method that can be cut.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method for forming a hook of a spring after feeding a length necessary for bending in addition to a hook engagement length from a quill feeding hole. Then, the forming tool is advanced to the front surface of the wire rod to be fed, and the front hook is bent, and then the cutter is advanced to cut the extra straight portion at the front hook tip with the metal core, and then the front hook base and body portion are continued. The molding is performed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an automatic coil spring forming apparatus having hooks at both ends for carrying out the method of the present invention will be described in Japanese Patent Publication No. 62-22 / 1987.
No. 698 can be formed by adding some tools. This configuration will be described with reference to FIGS. A quill 11 having a wire feeding hole is provided at the center of the tool mounting plate 10 at a right angle, and each tool is mounted on a radial tool mounting portion around the quill 11 and is rotated by a rear large gear (not shown). The cam moves the tool forward and backward. A slide holding plate 21 is fixed horizontally to the right of the quill 11, and a cutting tool 1 is provided at the tip of a slider 31 slidably provided toward the quill 11.
Is mounted and the cam follower 3
2 is controlled to advance and retreat.

Similarly, two slide holding plates 22 and 28 are fixed diagonally to the upper right, a cutting tool 8 is attached to a lower slide, and a contact tool 2 is attached to an upper slide. You. Similarly, just above the slide holding plate 2
A molding tool 3 having a diagonal molding surface with a molding groove is attached to the slide and is controlled to advance and retreat. A lever 35 pivotally supported at one end and having a cam follower 36 is provided at the upper left side, and a rod 37 at the tip is pivotally connected to a crank lever 39 pivotally supported by a bracket 38 fixed to the tool mounting plate 10. . The other end of the crank lever 39 is engaged with a slider 40 slidable in parallel with the axis of the quill 11, and the pressing / bending tool 4 attached to the slider is moved slightly below the feeding hole of the quill 11. It is controlled so as to advance and retreat from immediately before.

Similarly, a slide holding plate 25 is horizontally disposed on the left side.
Is fixed, and the metal core tool 5 attached to the slider is controlled to advance and retreat. Furthermore, a slide holding plate 2 is provided diagonally below left.
6 is fixed, and the bending tool 6 is attached to the slider to control the forward / backward movement. Further, a first movable holding arm 12 for holding the body of the coil is provided on the lower side of the quill 11 so as to be rotatable about a horizontal axis, and is provided with a fixed holding piece 13 for receiving a spring which is held and turned downward. A second movable holding arm 14 for gripping the spring (FIG. 18) and a raising tool 15 having a triangular top for raising the second hook are provided (FIG. 1).
9) This is the same as in Japanese Patent Publication No. 62-22698.

Next, a forming process of the tension spring shown in FIG. 6 will be described with reference to FIGS. Move the left metal core tool 5 forward and place a semicircular metal core 5 under the front feeding hole of the quill 11.
Position a. The feed roller feeds a predetermined length necessary for bending longer than the dimension A of the straight portion Sa at the front end of the hook from the feeding hole (FIG. 7). The portion of the straight portion longer than A is a setup straight portion necessary for reliably bending when the radius of curvature of the hook is smaller than the wire diameter.

The forming tool 3 immediately above is lowered, and the forming groove of the forming surface 3a which is inclined is instantaneously brought into contact with the wire to bend the primary bending Sb of the front hook by about 1/4 circle (FIG. 8). In this state, the bent portion does not sufficiently extend along the metal core 5a, and the required bending angle as a hook is not obtained. So press bending tool 4
Moves forward from the front of the quill 11 toward the quill 11, pushes the wire, and bends along the core 5 a of the metal core tool 5,
Make a solid arc (Figure 9). In the pushing state of the pressing and bending tool 4, the cutting tool 1 advances from the right side and cuts a wire portion of a portion longer than A of the front hook tip Sa with the cutting blade 5b below the metal core portion 5a of the metal core tool 5 (FIG. 10).

The pressing / bending tool 4 and the cutting tool 1 are retracted and clicked .
The straight portion Sc of the hook base is sent out from the feeding hole of the file 11 (FIG. 11). Straight portion S c and the body portion S of the hook base to instantly contact with the forming tool 3 is lowered wire from directly above
A quarter arc of the connection with d is created (FIG. 12). Next, the contact metal tool 2 advances from the upper right side to contact the side surface of the 1/4 arc of the wire, and the bending tool 6 advances from the lower left side to bend the front hook to about 45 °. That is, the front hook is raised (FIG. 13). The forming tool 3 is lowered to come into contact with the wire, and the wire is sent out from the feeding hole of the quill 11 to coil the body portion Sd by a predetermined length (FIG. 14).

[0011] feeding of the wire in the signal of the front hook angular position detector (not shown) at the end of the coiling of the body portion S d is stopped, after the forming tool 3 raised retracted, linear portion Se of the base of the rear hook quill 11 fed out from the feeding hole (Figure 15). The forming tool 3 is lowered and instantaneously abuts on the wire, and the primary bending Sf of the bent portion of the rear hook is about 1/4.
Create an arc (Fig. 16). The forming tool 3 is raised and the pressing and bending tool 4 is advanced to press the bent portion along the metal core 5a to form a reliable arc (FIG. 17). Thereafter, the forming tool 3 and the pressing / bending tool 4 are retracted, and the wire is sent out with the dimension A of the required straight portion Sg of the rear hook.

[0012] backside of the cutting tool 8 of the first movable clamping Jiude 12 core metal tool 5 is retracted to grip the body portion S d of the coil spring rotates the right obliquely upward from straps tool 2 is advanced quill 11 is cut at the rear hook end (FIG. 1).
8). Next, the first movable holding arm 12 rotates downward and the coil spring abuts on the fixed holding piece 13 (FIG. 18), and the second movable holding arm 14 rotates to apply the coil spring to the fixed holding piece 13. Hold. The bending and raising tool 15 at the top of the triangle rises from below to raise the rear hook (FIG. 19), and the forming of the coil spring having the hooks at both ends is completed.

[0013]

As described above, the present invention has the following effects. Since a trimming process was inserted in the middle of one process to cut a straight part for bending the hook provided at the tip of the front hook, there was no variation in trimming that would occur when transferring and positioning and fixing after molding, and stable. Quality can be obtained. Also one
Since the transfer is performed in the middle of the process, the waste time of transfer can be omitted, and the production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a tool arrangement of an automatic extension spring forming apparatus for carrying out a method of the present invention.

FIG. 2 is a view showing an arrangement of a press bending tool.

FIG. 3 is a front view of a metal core tool.

FIG. 4 is a plan view of the same.

FIG. 5 is a side view of the same.

FIG. 6 is an example of a tension spring.

FIG. 7 is a view showing a spring forming step and a view showing generation of a straight portion of a front hook.

FIG. 8 is a view of a primary bending of the front hook.

FIG. 9 is a diagram showing the pushing and bending of the front hook.

FIG. 10 is a diagram for cutting an extra length of the front hook.

FIG. 11 is a diagram showing generation of a straight base of the front hook.

FIG. 12 is a view of a base bending of the front hook.

FIG. 13 is a view of 45 ° bending of the front hook, that is, raising of the hook.

FIG. 14 is a view of the body part molding.

FIG. 15 is a diagram showing generation of a straight base of the rear hook.

FIG. 16 is a view of the primary bending of the rear hook.

FIG. 17 is a view showing the pushing and bending of the rear hook.

FIG. 18 is a view showing cutting and spring transfer of the spring.

FIG. 19 is a view showing hook raising of a rear hook of a transferred spring.

[Explanation of symbols]

1,8 Cutting tool 2 Backing tool 3 Forming tool 4 Push bending tool 5 Core metal tool 6 Bending tool 11 Quill 12 First
Movable holding arm 13 Fixed holding piece 14 Second
Movable clamping arm 15 Raising tool

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-196130 (JP, A) JP-A-55-133836 (JP, A) JP-A-2-28339 (JP, U) 4474 (JP, B2) JP-B 62-22698 (JP, B2) JP-B 62-43768 (JP, B2) JP-B 49-49108 (JP, B1)

Claims (1)

(57) [Claims] In a spring hook forming method, after a length necessary for bending is fed out from a quill feeding hole in addition to a hook engaging length, a forming tool is advanced to a front surface of a wire to be fed and abutted. Bending the front hook, then advance the cutter, cut the extra straight portion at the tip of the front hook with the metal core, and continue to form the front hook base and body, and cut the hook end during one process. A method of forming a spring incorporating a process.