JPS6243768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method of forming a hooked coil spring.

Coil springs with hooks at both ends using multiple forming tools and cutting tools arranged radially in a plane perpendicular to the feeding direction of the continuously fed wire rod have already been manufactured for quite some time, and new The applicant previously proposed a manufacturing method in JP-A No. 55-117537, which made it possible to form a wide range of springs such as long hook springs and springs with different diameters in which the hook diameter and the coil diameter are different. However, even with this method, research continued to be carried out to improve the quality of the product, and in the previous proposal, in a coil spring with hooks at both ends, the hook ends of the front hook and rear hook were straight parts as shown in Figure 1. It is formed. For this reason, there was a problem in that it was difficult to create a gap between the cut ends of the hook to a desired size. When manufacturing a coil spring, the outer diameter of the coil spring is determined by the distance from the quill tip to the forming tool, so a space is always required between the quill tip and the forming tool. However, in conventional coil spring manufacturing machines, the wire being sent out is cut at the tip of the quill.
Since the beginning of winding of the next front hook is fed in a straight line until the winding starts using a forming tool, it is common for there to be a straight part at the tip of the front hook.

Further, at the end of winding the rear hook, the distance between the forming point where the quill was formed into an approximately semicircle and the cutting point of the tip of the quill cut by the cutting tool when the forming tool retreats remains as a straight line.

Therefore, the present invention has been made with attention to this point, and the molding of the rear hook of the coil spring is approximately
Add 1/4 and insert the core metal so that it touches the back side of the hook, and set the cutting tool position so that it leaves an arc of 1/4 of the radius of the coil from the feeding point, and set the cutting direction of the cutting tool 90 degrees. Installed so that it works by shifting the angle,
When the coil spring is cut, the end of the rear hook is cut at the circular arc part, and a 1/4 circular arc part remains at the tip of the quill, and the forming tool is advanced to the front hook for the next coil forming, and the wire rod is cut off. It is characterized by a molding method that allows hook molding to be performed simultaneously with feeding.

Embodiments of the present invention will be described below based on the drawings. A wire rod feeding hole 3 is provided in the center, a sliding slope 4 to the right is provided below the feeding hole 3, and a notch 4a is provided on the right side.
The quill 2 provided with the quill 2 is fixed by protruding a certain length from the mounting surface 1, and the upper part of the quill 2 on the mounting surface 1 is extended to the front of the feeding hole 3 as shown in FIG. Wire rod W fed out to the front perpendicular to surface 1
and slide it on the sliding slope 4 to form the notch 4a.
A curve forming tool 5 provided with an oblique groove 5a for forming a spiral curved portion C of a certain radius by feeding the spiral curved portion C into a spiral curved portion C having an appropriate number of turns as shown in FIG. 2 is installed. The tool 5 is controlled by a cam 6 and the first
Figure 2: Advance and stay in position and withdrawal time and wire rod W
You can freely curve it by 180 degrees, curve it by 90 degrees, or create a spiral curved part in harmony with the feeding speed. A first forming tool 8 is provided diagonally to the upper right of the quill 2, as shown in FIGS. 8 and 13, and is advanced by the control of a cam 7 to a position in contact with the flank of the feeding member W at the front of the feeding hole 3. On the left side of Quill 2,
A receiving surface 9 that moves in the left and right horizontal directions under the control of the cam 10 and is always located below the feeding hole 3 of the quill 2.
Instead of a, a core metal tool 9 is provided whose receiving surface 9b supports the circular arc portion when cutting the rear hook end in the advanced position shown in FIG. On the left side of the quill 2, a cutting tool 13 for cutting the coil spring is provided on a swinging arm 12 which overlaps the core metal tool 9 in the feeding direction of the wire rod W and is controlled by a cam 11. A second forming tool 15 is provided at the diagonally lower left portion of the quill 2 so as to be moved slightly to the right with respect to the first forming tool 8 that has advanced, as shown in FIGS. Further, on the right side of the quill 2, a movable contact plate 16 for positioning the upper part of the spirally curved portion C on the front surface of the mounting surface 1 is rotatably supported by a shaft 17. An insertion plate inserted between the spirals of the curved part of the coil spring positioned at the upper position by the movable contact plate 16 at the end of the movable arm 19 rotatably supported by the parallel shafts 18 below the shaft 17; , a movable holding plate 20 having a V surface that receives the lower part of the curved portion C is pivotally supported, and a roller at the lower end of the movable holding plate 20 is guided by a cam groove 21 inclined with respect to the mounting surface 1 and is placed above the coil spring receiving part. The coil spring is held and moved in parallel between the bent position and the lower position of the rear hook. The movable holding plate 20 described above
A clamping device is installed which produces a clamping action of the helical curved portion C held on the insert plate when it is translated in parallel to the lower position. This clamping device has a fixing piece 23 provided with a receiving groove 22 that comes into contact with the rear outer periphery of the left portion of the helical curved portion C when the movable holding plate 20 swings forward and downward, protrudes from the support surface 1, and further extends from the support surface 1. A curving auxiliary tool 24, which is in contact with the upper half of the left end surface of the shaped curved portion C, is attached and protrudes from the support surface 1, and is further supported by a shaft 25, and by the swinging of a movable arm piece 27 that is rotated by a vertically movable rod 26. The aforementioned receiving groove 22
A pinch groove 28 is provided to press against the outer periphery of the first half of the spirally curved portion C fitted into the quill 2, and a third forming tool 31 is connected to the shaft 30 at the upper part of the continuous sweat 29 that moves up and down below the quill 2. The left protrusion of the third forming tool 31 is provided with a triangular forming tip 32 at the upper end of the tool 31 that rises in contact with the inner line of the straight leg d that extends downward continuously from the spirally curved portion C. guide roller 3
3 is provided, and the third forming tool 31 touches the inclined surface 3 of the cam plate 34 midway up.
6 and the guide roller 33, the tip 32 is tilted to the left as shown in FIG.

Furthermore, the relationship between the core metal tool 9 and the cutting tool 13, which are particularly improved components, will be explained. The core metal tool 9 has a slider 102 that can slide left and right on a bracket 101 fixed to the mounting surface 1. The core metal tool 9 having a tip shape as shown in FIGS. 5, 6, and 7 is fixed to the end of the slider 102.
02 Cam stand 105 on which the roller 104 at the rear end rotates
A cam 10 attached to the cam 10 advances and retreats from a state where the receiving surface 9a is located directly below the feeding hole 3 to a position where the receiving surface 9b is directly below for cutting the coil spring. The cutting tool 13 is attached to the bracket 10 on the upper side of the cam stand 105.
The slider 111 is guided by two guide rods 110 provided parallel to the slider 1, and the bracket 101 has a swinging fulcrum, and the cutting edge 9c of the cored metal tool 9 is positioned at the advanced position of the cored metal tool 9.
The swinging arm 12 is connected to a swinging arm 12 to which a cutting tool 13 is attached, with the cutting blade facing approximately at the center of the arc of the rear hook of the coil spring. Roller 11
3 is swing-controlled by the cam 11 of the cam stand 105. The above-mentioned parts produce a harmonious operation as described in the following embodiment of the molding method.

Next, a method for continuously forming a coil spring having hooks at both ends using the above-mentioned continuous forming apparatus for coil springs will be described. Quill 2 feeding hole 3
From there, the wire rod W is fed out with the feeding speed being made variable depending on the work program. As shown in FIG. 9, at the beginning of forming, the wire rod W has already been slightly fed out to the cut end, forming an approximately 1/4 arc on the outside of the receiving surface 9a of the core metal tool 9, and the curved forming tool 5 Advancing to the front of the outlet 3 (Fig. 10), making the first semicircular bend A to the wire W, and then immediately withdrawing it upward.
After that, the wire rod W is fed out in a straight line to form the front hook a and the straight leg part b as shown in FIG. expanded to wire rod W.
A second 90° bend is made so that the straight leg b faces downward, and then it is immediately withdrawn, and in place of this, the first forming tool 8 and the second forming tool 15 are moved to the advanced position, respectively, and the straight leg b is turned downward. Proceed as shown in the diagram, and at the tip, attach leg b.
Immediately after making the third bend C by bending it 90 degrees to the right as shown in Figure 13,
The forming tool 8 and the second forming tool 15 are moved back to their original positions, and the curved forming tool 5 is advanced as shown in FIG. 14 in accordance with FIGS. 10 and 12, and the front hook a
While going around and around, the spiral curved part c has the required number of turns.
is sent out to the right as shown in Fig. 15 to form it. After that, the curve forming tool 5 is removed and the feeding hole 3 is removed.
The straight leg part d of the rear hook e is formed before the quill 2, and at the same time the front hook a, the spirally curved part c, etc. are moved to the front side of the quill 2, and then the fourth curve forming tool 5 is formed.
16, a 3/4 circular fourth curve 2 is formed at the rear end of the straight leg d as shown in FIG.
At this time, the spirally curved part c, etc., which had been moving forward from the quill 2, swings about 270 degrees from below to the rear and further upwards as shown in the figure, and the upper part of the curved part c is held in a predetermined position by the spring. It is brought into contact with the lower surface of the movable contact plate 16 that is being pushed. At the same time, the curve forming tool 5 is moved back. Next, the movable holding plate 20 is lifted and the plate is inserted between the spirals in the middle of the curved portion c of the coil spring positioned by the movable contact plate 16, and the plate is inserted up to the V plane as shown in FIGS. 18 and 19. At the same time, the core metal tool 9 advances and the core metal tool 9
The pedestal 9b of the wide part eliminates the gap with the rear hook part, and the cutting tool 13 advances in the wire feeding direction below the feeding hole 3 by the radius of the hook as shown in FIG. Cut the receiving surface 9b with about 1/4 of the rear hook remaining between the cutting edge 9 and the cutting edge 9. Thereafter, the cutting tool 13 is moved back, and the movable holding plate 20 is moved in parallel to the lower position as shown in FIGS. Then, as shown in FIG. 22, the movable arm piece 27 is moved upward and rearward about the shaft 25 using the cam and the vertically movable rod 26, and the left part of the curved portion c is clamped by the pinch groove 28. . Movable holding plate 2
0 moves downward and the insertion plate is pulled out from the spiral portion. At this time, the left end of the curved portion c contacts the curve auxiliary tool 24 as shown in FIG. As the movable holding plate 20 swings forward and downward, the cut end of the rear hook e moves downward from the front of the quill 2 as shown in FIG. The bending forming tool 5 is allowed to advance as shown in FIG. 10 to perform the next forming of the coil spring shown in FIG.

The third forming tool 31 is moved upward by the other connecting rod 29.
However, at the beginning, the roller 33 of the third forming tool is attached to the cam plate 3.
The triangular shaped tip 32 touches the right side of the straight leg d which has descended from the left end surface of the spiral curved part c, and attempts to rise as shown in FIG. 23. However, as shown in FIG.
A fifth bending E is created by bending at right angles to the left side, and then the movable arm piece 27, the connecting rod 29, and the third forming tool 31 are moved back to eject the product, the coil spring shown in FIG. 2, downward.

In the embodiment described above, the feeding of the wire rod is temporarily stopped during the bending and cutting shown in FIG. 13, but the feeding speed is arbitrarily controlled or stopped in other steps as well.

As described in detail above, the present invention is such that the cutting position of the rear hook in the manufacturing method of JP-A-55-117537, which was proposed earlier, is cut leaving a part of the circular arc that is to become the front hook. Both the end and rear hook end start and end with a circular arc, and there are no straight parts, so the gap between the cut end of the hook and the length of the bent part of the hook can be manufactured to the correct dimensions and molding required by the drawing, improving product quality. It has characteristics that can make it possible.

[Brief explanation of the drawing]

The accompanying drawings show embodiments of the present invention, and FIG. 1 is a plan view of a conventional coil spring with hooks at both ends;
Fig. 2 is a plan view of a coil spring with hooks at both ends made by the method of the present invention, Fig. 3 is a front view of the device, Fig. 4 is a sectional view taken along the line A--A in Fig. 3, and Fig. 5 The figure is a perspective view of a core metal tool, FIG. 6 is a view taken in direction B of FIG. 5, and FIG. 7 is a perspective view of another form of the core metal tool.
FIG. 8 is a front view showing the relationship between the feeding hole 3, the first forming tool 8, the core tool 9, and the second forming tool 15, and FIGS. 9 to 24 are explanatory views showing the manufacturing method in the order of steps. ,14,15,17,18,21,23,
Figure 24 shows a front view, and the other parts show a side view. 2... Quill, 3... Feeding hole, 5... Curved forming tool, 8... First forming tool, 9... Core metal tool, 1
5...Second forming tool, 16...Movable contact plate, 20...
...Movable holding plate, a... Front hook, b... Straight leg part, c... Spiral curved part, d... Straight leg part, e...
...rear foot.

Claims (1)

[Claims] 1 A plurality of forming tools and cutting tools provided radially in a plane perpendicular to the feeding direction of the wire rod move forward and backward in accordance with the timing of the cam and are continuously fed out, or from a temporarily stopped wire rod to a hook section. And in the method of continuously forming a spiral curved part, there is a space between the inside of the wire rod curved by the forming tool and the wire rod feeding hole, which serves as a cradle for the wire rod when the wire rod is cut by the cutting tool and one of the wire rods. A method for forming a hook end of a coil spring with a hook, characterized by inserting a core bar serving as a cutting edge without a gap and cutting it leaving a part of the circular arc portion that should become a front hook.