JP3030688B2 - Spiral spring forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding core having a "-"-shaped winding core retaining portion, a spiral spiral coil portion acting as a spring, and a rear end portion. The present invention relates to a method for forming a spiral spring shown in FIG.

[0002]

2. Description of the Related Art In the prior art, a wire S is fed out of a wire guide 12 as shown in FIGS. 6A and 6B, and a leading end of the wire S is inserted into a notch groove 13a of a core winding tool 13. After the insertion, the feeding of the succeeding wire S from the leading end is stopped, the core winding tool 13 is rotated, and the wire S is wound along the outer periphery thereof to form a "-"-shaped core hooking portion Fj. And
After retracting the core winding tool 13 to separate it from the core hooking portion Fj, a spiral tool (not shown) is brought into contact with the outer periphery of the core hooking portion Fj, and The succeeding wire S is again fed forward, abuts against a spiral tool to form a spiral coil having a predetermined number of turns, and a cutting die (not shown) is brought into contact with a predetermined position of the subsequent wire S from the spiral coil. There is known a method of forming a spiral spring by advancing a cutting (not shown) punch from a direction facing a cutting die to cut a rear end of a wire S.

[0003]

According to the above-mentioned prior art, when forming a "-"-shaped core winding hook Fj, FIG.
Since the core winding tool 13 having a fixed axis shown in FIGS. 6A and 6B is rotated and the wire S is wound along the outer circumference, the winding angle is 0 ° shown in FIG. As the winding diameter increases to the state of the winding angle of 360 ° shown in FIG.
A bent portion Gj is formed in the wire S near the exit of the wire guide 12, and when the core winding tool 13 is retracted to separate from the core hooking portion Fj, the core hooking portion Fj is spring-backed by the bent portion Gj. 6B, the refraction angle becomes smaller, but an unnecessary refraction portion Gj remains as shown in FIG.

[0004] For this reason, when the spiral coil portion is formed next, there is a problem that the coil curvature to be formed in the spiral shape is locally deformed in the above-described refraction portion Gj, thereby deteriorating the spring function of the spiral spring. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object the purpose of forming a "-"-shaped winding core hooking portion from the start of winding to the end of winding. It is an object of the present invention to provide a method of forming a spiral spring in which a wire drawn from a wire guide is held substantially in a straight line so that the above-described bent portion is not formed in a wire near an outlet of the wire guide. .

[0006]

In order to achieve the above-mentioned object, a spiral spring forming method of the present invention is to feed a wire material forward of a wire guide and to form a notch groove formed at one end of a core winding tool. After the leading end of the wire is inserted, the feeding of the wire is stopped, the core winding tool is rotated to wind the wire along the outer periphery thereof, and the bent portion of the winding end and the wire guide are wound. In order to keep the wire drawn from the wire substantially straight, the core winding tool is sequentially moved in a direction perpendicular to the wire drawn from the wire guide, and the wire is formed into a "-"-shaped core hook portion. After retracting the core winding tool from the core hooking portion, the spiral tool is brought into contact with the outer periphery of the core hooking portion, and the subsequent wire rod from the core hooking portion is removed. Unwind forward and abut against the spiral tool, The coil is formed into a spiral coil part having a predetermined number of turns continuous with the part, a cutting die is brought into contact with a predetermined position of a subsequent wire rod from the spiral coil part, and a cutting punch is advanced from a direction opposite to the cutting die to advance the rear end of the wire rod. Is cut to form a spiral spring.

A rear end portion of the wire following the spiral coil portion is a rear end hooking portion having a bent portion for hooking, and the rear end hooking portion has at least one concave molding. A bending die having a surface formed thereon and capable of moving forward and backward at the same time as the cutting die; and a bending punch having at least one convex forming surface formed thereon and capable of moving forward and backward at the same time as the cutting punch. The wire is sandwiched and pressed between the forming surface and the convex forming surface of the bending punch to form a bent portion for hooking at the rear end hooking portion.

Further, the wire formed into the spiral spring can be formed by a plate-shaped wire.

As described above, according to the present invention, the wire drawn from the wire guide can be held substantially in a straight line from the start of winding to the end of the winding forming the "-"-shaped core winding hook.
An unnecessary bending portion is not formed on the wire near the exit of the wire guide. Therefore, when the spiral coil portion is formed next time, the curvature of the spirally formed coil increases smoothly, and the spiral spring thus formed can maintain a predetermined spring function.

At the same time as the cutting of the wire, the wire is sandwiched and pressed between the concave forming surface of the bending die and the convex forming surface of the bending punch to form a bent portion for hooking at the rear end hooking portion. As a result, the spiral spring having the core hook portion and the rear end hook portion can be automatically and continuously formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention, which relates to a method for forming a spiral spring, will be described below with reference to FIGS.

FIGS. 1 and 2 show the core catching portion shown in FIGS.
It is an explanatory view showing a form of molding from just before the start of winding shown in (a) (winding angle is 0 °) to the end of winding shown in FIG. 2C (winding angle is 360 °), Tools for shaping the spiral coil and cutting the rear end are omitted, and FIG.
2B and 2C, and FIGS. 2B and 2C, the feed roller is omitted.

Further, the pair of feed rollers 1A and 1B are configured to be rotatable and to be able to perform arbitrary positioning control of the rotation angle. The wire guide 2 has a wire guide groove 2a formed so that the wire S can be moved only in the left-right direction in the drawing.
The core winding tool 3 has a notch groove 3a at one end of the cylindrical body, which can insert the wire S perpendicular to the axis, and a notch groove 3a at one end on the counterclockwise rotation rear side. A semi-circular angle 3b is formed, and is rotatable about an axis; and
Arbitrary positioning control of the rotation angle is configured.
In addition, although the winding angle at the end of winding of the winding core hooking portion shown in FIG. 2C of this example is illustrated as 360 °, in the range of approximately 300 ° to approximately 400 ° from the start of winding, The coil forming of the next spiral coil portion can be performed.

FIG. 3 is an explanatory view showing the spiral coil portion just before the coil forming shown in FIG. 3A and immediately before the coil forming shown in FIG. 3B ends. The tools for forming and cutting the rear end are omitted. Further, the spiral tools 4 and 4 are attached to the tool holder 9 at a predetermined distance, and the tool holder 9 can move forward in a diagonally right upward direction and retreat in a diagonally left downward direction. In addition, it is configured to enable arbitrary positioning control. Although the number of the spiral tools 4 and 4 is shown in the figure, when the coil diameter of the spiral coil to be formed is large, the spiral tool may be formed using three or more spiral tools.

FIG. 4 is an explanatory view showing a state immediately after the cutting of the rear end portion, in which tools for forming the core hooking portion and the spiral coil portion are omitted. Also, the cutting die 5
The upper left corner is formed as a cutting blade, and the left side surface is configured to be able to move up and down below the left end of the front end surface of the line guide 2. The cutting punch 6 has a lower right corner formed on a cutting blade, and is configured to be vertically movable at a position where the right side of the cutting blade approaches or slides on the left side of the cutting die 5.

The method of forming a spiral spring of the first example is to first form a core hook portion, then form a spiral coil portion, and finally cut a rear end to form a spiral spring. Is what you do.

First, when forming the core hook portion, FIG.
As shown in (a), a pair of feed rollers 1A, 1B are respectively brought into contact with the wire S, the wire S is sandwiched by the feed rollers 1A, 1B, and the feed roller 1A is rotated clockwise by 1B in the direction of the arrow. Are rotated in the directions indicated by the counterclockwise arrows.

Then, the wire S sandwiched between the feed rollers 1A and 1B is fed forward from the wire guide groove 2a of the wire guide 2, and is substantially in line with the wire S fed from the wire guide 2 (ie, is fed from the wire guide 2). The distal end of the wire S is inserted into the notch groove 3a of the core winding tool 3 which is positioned at the center distance La = 0 between the wire S and a core winding tool 3 described later and stands by in front of the wire guide 2. After, feed roller 1
A and 1B are respectively moved in a direction away from the wire S as shown by a two-dot chain line to release the pinching and rotation of the wire S by the feed rollers 1A and 1B.

Next, as shown in FIG. 1 (b), the core winding tool 3 is rotated counterclockwise in the direction of the arrow, and the wire rod S is formed by the notch groove 3a and the semicircular corner 3b of the core winding tool 3. While winding the wire S along the semicircular corner 3b of the core winding tool 3 while pulling out the wire guide 2 in the direction of the leftward arrow from the wire guide 2, and forming a bent portion Fb formed by the semicircular angle 3b of the core winding tool 3. In order to keep the wire S pulled out from the wire guide 2 substantially straight, the core winding tool 3 is sequentially lowered in the direction of the downward arrow (a direction perpendicular to the wire S drawn out from the wire guide 2), and The center distance Lb between the drawn wire S and the core winding tool 3 is displaced. here,
At the tip of the bent portion Fb, a straight line portion F in the shape of a ""
a is formed.

Next, as shown in FIG. 1C, the core winding tool 3 is subsequently rotated in the same direction, and the wire S is pulled out from the wire guide 2 while the semi-circular corner 3b of the core winding tool 3 is pulled out.
From the wire guide toward the outer periphery to form the bent portion Fb, and in order to keep the bent portion Fb and the wire S drawn out from the wire guide 2 substantially in a straight line, the core winding tool 3 is successively moved in the same direction. The center distance Lc between the wire S drawn out from the wire guide 2 and the core winding tool 3 by being lowered
Is displaced.

Next, as shown in FIG. 2A, the core winding tool 3 is successively rotated in the same direction, and while the wire S is being pulled out from the wire guide 2, the wire S is moved along the outer periphery of the core winding tool 3. And the core winding tool 3 is successively lowered in the same direction in order to keep the bent portion Fc at the winding end and the wire S drawn out from the wire guide 2 substantially in a straight line. Wire S drawn out and core winding tool 3
Is displaced from the center distance Ld.

After the wire S abuts along the outer circumference of the core winding tool 3 having a constant radius, the radius of the bent portion Fc at the winding end from the center of rotation becomes constant. Part F
Since the center of rotation of the core winding tool 3 can be held substantially in a straight line at a fixed position between the wire c and the wire S pulled out from the wire guide 2, the wire S abuts along the outer circumference of the core winding tool 3 having a constant radius. After that, the center distance Ld between the wire S drawn out from the wire guide 2 and the core winding tool 3 is not displaced.
The descent of the core winding tool 3 is stopped, and this stop position is maintained.

Next, as shown in FIG. 2 (b), the core winding tool 3 is subsequently rotated in the same direction, and the wire S is drawn out from the wire guide 2 along the outer periphery of the core winding tool 3. Is wound. Note that the center distance between the wire S and the core winding tool 3 is not changed from the state shown in FIG.

Next, as shown in FIG. 2 (c), the core winding tool 3 is rotated counterclockwise from the beginning of winding in FIG. When this is done, a "-"-shaped winding core hooking portion F is formed. Springback acts in the clockwise arrow direction opposite to the winding direction on the core hook portion F in this state, and the core hook portion F rotates the engagement portion with the core winding tool 3 clockwise. Press in the direction of the arrow,
When the core winding tool 3 is retracted in the rotational axis direction, which will be described later, the core winding tool 3 may pull the core hook portion F in the retreating direction, or the core winding tool 3 may not be smoothly retracted. easy.

In order to prevent this phenomenon, the core winding tool 3
Is stopped at a position rotated 360 ° in the counterclockwise direction from the winding start, and the core winding tool 3 is moved clockwise from the 360 ° position by the action of the springback described above. Rotate. Then, in order to separate the core winding tool 3 from the core hooking portion F in preparation for forming the next spiral coil portion, the core winding tool 3 is retracted in the direction of the rotation axis and the core winding of the next work is hung. In preparation for forming the stop portion F, the position of the notch groove 3a of the core winding tool 3 is positioned at the winding start position shown in FIG. The center distance between the wire S and the core winding tool 3 is shown in FIG.
Since Lf is not displaced from the state shown in FIG.

In forming the next spiral coil, FIG.
As shown in (a), the feed rollers 1A and 1B separated from the wire S at the time of forming the core hook portion F are brought into contact with the wire S, respectively, and the wire S is fed by the feed rollers 1A and 1B. At the same time, the feed roller 1A is rotated in the counterclockwise arrow direction, and the feed roller 1B is rotated in the clockwise arrow direction.

Then, the wire S sandwiched between the feed rollers 1A and 1B is returned in the direction of the rightward arrow, so that the core hook portion F
Is positioned at a position near the front end of the wire guide 2, and the tool holder 9 is moved forward in the diagonally right upward direction so that the spiral tools 4, 4 are directed toward the center of the core hooking portion F. Then, the spiral tools 4 and 4 are brought into contact with the outer periphery of the core hook portion F.

Next, as shown in FIG. 3 (b), the feed roller 1A is rotated in the clockwise arrow direction, and the feed roller 1B is rotated in the counterclockwise arrow direction, so that the wire rod held between the feed rollers 1A and 1B is rotated. S is fed forward from the wire guide groove 2a of the wire guide 2, and the wire S is formed into a curved shape by abutting against the spiral tools 4 and 4, and the spiral is formed so as to sequentially increase the curved diameter being formed into the curved shape. When the tools 4 and 4 are retracted in the diagonally downward left arrow direction, the wire S that is continuous with the core hooking portion F is formed into a spiral coil.

However, after the wire S held between the feed rollers 1A and 1B is fed out from the wire guide groove 2a of the wire guide 2 by a predetermined length and the rotation of the feed rollers 1A and 1B is stopped, the spiral coil portion having a predetermined number of turns is obtained. C is formed. Then, in order to separate the spiral tools 4, 4 from the spiral coil portion C in preparation for the cutting of the next rear end portion R, the spiral tools 4, 4 are retracted in the diagonally downward left arrow direction and separated therefrom. The feed roller 1A holding the wire S is moved in the clockwise arrow direction and the feed roller 1B is moved in the counterclockwise arrow direction so that the rear end of the rear end portion R that is continuous with the spiral coil portion C is advanced to the cutting position. The wire S is fed out, and the rear end of the rear end portion R is positioned at a cutting position on the left side surface of the cutting die 5 described later.

At the time of cutting the next rear end, as shown in FIG. 4, the cutting die 5 is raised and positioned at a position where the wire S is sandwiched between the upper end surface and the lower surface of the front notch of the wire guide 2. . Then, the cutting punch 6 is lowered to bring the lower end surface into contact with the wire material S at the rear end portion R. After the contact, the cutting punch 6 is further lowered, so that the cutting formed at the upper left corner of the cutting die 5 is cut. The rear end of the rear end R is cut by the cutting blade and the cutting blade formed at the lower right corner of the cutting punch 6, and the spiral spring W is completed.

However, since a normal spiral spring is used by hanging the core portion of the spiral coil and the rear end outside the spiral coil, in this case, the spiral spring formed as described above is used. At the rear end R of W, a hook is formed by a press machine or the like.
With such a molding method, the production efficiency is low and the production cost is high. Therefore, if the molding is performed in the same step as the rear end cutting of the present invention described below, the production efficiency can be improved and the production cost can be reduced.

Next, a second embodiment of the present invention relating to a method of forming a spiral spring having a rear end hooking portion having a bent portion at the rear end for hooking will be described with reference to FIG. It is explained as follows.

FIG. 5 is an explanatory view showing a state immediately after bending and forming for cutting and hooking the rear end of the rear end hooking portion.
The tools for forming the core hook portion and the spiral coil portion are not shown in the figure. Further, since the cutting die 5 and the cutting punch 6 have the same configuration as those described in FIG. 4, they will be described using the same reference numerals. The bending die 7 has an uneven molding surface 7a formed on the upper surface, and the upper end surface is substantially flush with the upper end surface of the cutting die 5.
It is attached to the left side. The bending punch 8 has a convex molding surface 8a formed at the lower end, and is positioned at a position where the convex molding surface 8a meshes with the concave portion of the irregular molding surface 7a with the wire S interposed therebetween. It is attached to the surface.

The second example of the method of forming a spiral spring with a rear end hooking section is to first form a core hooking section, then to form a spiral coil section, and finally to form a rear end hooking section. The end is cut off, and a bent portion for hooking is formed on the rear end hooking portion to form a spiral spring with a rear end hooking portion. The first forming of the core hooking portion and the forming of the next spiral coil portion are the same as the forming method of the first example, and therefore description thereof is omitted, and the above-described spiral coil portion is formed. Thereafter, in preparation for the cutting of the next rear end, the description will be made assuming that the spiral tool is on standby at the rearward end and the rear end of the rear end is positioned at a cutting position on the left side surface of the cutting die 5 described later.

First, at the time of cutting the rear end hooking portion and forming the rear end hooking portion, as shown in FIG. 5, the bending die 7 was raised together with the cutting die 5 to form the bending die 7. The upper end surface of the uneven forming surface 7a is brought into contact with the rear end hooking portion H, and is positioned at a position where the wire S is sandwiched between the upper end surface of the cutting die 5 and the lower surface of the front end notch portion of the wire guide 2.
Then, the bending punch 8 is lowered together with the cutting punch 6, and the lower end of the convex forming surface 8a formed on the bending punch 8 is brought into contact with the rear end hooking portion H. The lower end surface is brought into contact with the rear end hooking portion H.

After the contact, the bending punch 8 is continuously lowered together with the cutting punch 6, and the cutting edge formed at the upper left corner of the cutting die 5 and the lower right corner of the cutting punch 6 are formed. With the cutting edge, the rear end of the rear end hooking portion H is cut, and the uneven molding surface 7 formed on the bending die 7 is cut.
a and the convex forming surface 8a formed on the bending punch 8 sandwich the rear end hooking portion H, and press and bend the bent portion Ha into a wavy shape to form a spiral spring with a rear end hooking portion. Wr is completed.

The material of the spiral spring formed by the present invention and the spiral spring with the rear end retaining portion may be a wire,
Alternatively, if a cross-sectional shape of each tool to be used is formed so as to be able to engage with the shape of the wire or the plate even if it is a plate, it can be formed by the above-described forming method.

[0038]

Since the present invention is configured as described above, it has the following effects.

In order to hold the bent portion of the winding end and the wire drawn out from the wire guide from the start of winding to the winding end for forming the "-"-shaped winding core hooking portion, Since the core winding tool is sequentially moved in the direction perpendicular to the wire, an unnecessary bending portion is not formed on the wire near the exit of the wire guide as in the related art. However, at the time of forming the next spiral coil portion, there is no local deformation of the coil curvature, and a spiral spring having a high spring function can be formed.

Further, in forming the spiral spring with the rear end hooking portion, a bent portion for hooking can be formed in the rear end hooking portion in the same process as the cutting of the rear end. Improvement and reduction in manufacturing cost can be achieved.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory views showing an embodiment of forming a core hooking portion according to the present invention, wherein FIG. 1A shows a winding angle of 0 °, FIG. FIG.

FIGS. 2A and 2B are explanatory views showing an embodiment of forming a core hooking portion according to the present invention, wherein FIG. 2A shows a winding angle of 180 ° and FIG.
Is a longitudinal sectional view at 220 ° and (c) is a longitudinal sectional view at 360 °.

FIGS. 3A and 3B are explanatory views showing an embodiment of spiral coil portion forming according to the present invention, wherein FIG. 3A is a longitudinal sectional view before forming and FIG.

FIG. 4 is an explanatory view of a vertical section showing an embodiment of rear end cutting according to the present invention.

FIG. 5 is an explanatory view of a vertical section showing an embodiment of cutting and bending for hooking a rear end hooking portion according to the present invention.

6A and 6B are explanatory views showing a form of forming a core hook portion according to a conventional technique, wherein FIG. 6A shows a winding angle of 0 °, FIG. 6B shows a 360 ° winding angle, and FIG. It is a longitudinal cross-sectional view in the state where the core winding tool was retracted after forming the hook portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A, 1B Feed roller 2 Wire guide 3 Core winding tool 3a Notch groove 4 Spiral tool 5 Cutting die 6 Cutting punch 7 Bending die 8 Bending punch C Spiral coil part F Core hook part Fc Core hook part winding end H Rear end hooking part La-Lf Center distance between wire and core winding tool S Wire R Rear end W Spiral spring Wr Spiral spring with rear end hooking

Claims (3)

(57) [Claims] 1. A tip of a wire is inserted into a notch groove of a core winding tool, and the core winding tool is rotated, and a subsequent wire is wound around the outer periphery of the tool from the tip to form a "" shape. It is formed into a core hooking portion, a spiral tool is brought into contact with the outer periphery of the core hooking portion, and a subsequent wire rod is fed forward from the core hooking portion to abut against the spiral tool, and It is formed into a spiral coil part having a number of turns, and a cutting die is brought into contact with a predetermined position of a subsequent wire rod from the spiral coil part, and a cutting punch is advanced from a direction facing the cutting die to cut a rear end of the wire rod. A spiral spring forming method for forming a spiral spring, comprising: feeding a wire in front of a wire guide, inserting a leading end of the wire into a notch groove formed at one end of a core winding tool, and then forming the wire. Stop feeding, rotate the core winding tool, and move the wire rod along its outer circumference. While winding, the core winding tool is sequentially moved in a direction perpendicular to the wire drawn from the wire guide so as to keep the bent portion of the winding end and the wire drawn from the wire guide substantially straight. Is formed into a "" -shaped core winding portion, and after retracting the core winding tool from the core winding portion to separate the core winding tool, a spiral coil portion continuous with the core winding portion is formed. And cutting the rear end to form a spiral spring. 2. A rear end portion of a wire rod subsequent to the spiral coil portion according to claim 1 is a rear end hooking portion having a bent portion for hooking, wherein the rear end hooking portion has a bent portion. A bending die having at least one concave forming surface formed thereon and capable of moving back and forth simultaneously with the cutting die; and a bending punch having at least one convex forming surface formed thereon and capable of moving back and forth simultaneously with the cutting punch. 2. A bent portion for hooking is formed at the rear end hooking portion at substantially the same time by sandwiching and pressing a wire between the concave forming surface of the bending die and the convex forming surface of the bending punch. 3. The method for forming a spiral spring according to item 1. 3. The method for forming a spiral spring according to claim 1, wherein the wire formed into the spiral spring is a plate-shaped wire.