JPH09206866A - Method for forming spiral spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming method of a spral spring without forming unnecessary bent part between a core hooking part of the spiral spring and a spiral coil part. SOLUTION: When a core hooking part is formed, a wire S held by feed rollers 1A, 1B is fed forward of a wire guide 2, a tip part of the wire S is inserted in and held by a notched groove 3a of a core tool 3 which is positioned approximately straight to the wire S, and then the holding and feeding of the wire S is released. The core tool 3 is turned counterclockwise, and the wire S is wound around a semi-circular corner 3b while the wire S is fed from the wire guide 2, and the core tool 3 is successively lowered so as to keep a bent part Fb and the wire S approximately straight, and the distance Ld between centers of the wire S and the core tool 3 is displaced. The core tool 3 is successively lowered, and turned in the same direction, and positioned at the location of 360 deg. from the start of winding, and stopped to form a core hooking part F of circular shape with a line therein.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In the prior art, as shown in FIGS. 6 (a) and 6 (b), a wire rod S is fed out in front of a wire guide 12 and a tip portion of the wire rod S is inserted into a notch groove 13a of a core winding tool 13. After the insertion, the feeding of the succeeding wire rod S from the tip end is stopped, the core winding tool 13 is rotated, and the wire rod S is wound along the outer periphery of the core winding tool 13 to form a "-"-shaped winding core hooking portion Fj. Then
After retracting the core winding tool 13 from the core retaining portion Fj so as to be separated from the core retaining portion Fj, a spiral tool (not shown) is brought into contact with the outer periphery of the core retaining portion Fj, and from the core retaining portion Fj. The succeeding wire rod S is again fed forward and collided with the spiral tool to form a spiral coil portion having a predetermined number of turns, and a cutting die (not shown) is brought into contact with the predetermined position of the subsequent wire rod S from the spiral coil portion. A method is known in which a cutting (not shown) punch is advanced from the direction opposite to the cutting die to cut the rear end of the wire S to form a spiral spring.

[0003]

According to the above-mentioned conventional technique, when forming the "-"-shaped winding core retaining portion Fj, as shown in FIG.
Since the core winding tool 13 having a constant axis shown in (a) and (b) is rotated and the wire S is wound along the outer periphery thereof, the winding angle 0 ° shown in FIG. As the winding diameter increases in the winding angle of 360 ° shown in FIG. 6 (b),
A bending portion Gj is formed on 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 locking portion Fj, the core locking portion Fj is springback of the bending portion Gj. , And the refraction angle becomes smaller by moving downward, but unnecessary refraction portion Gj remains as shown in FIG. 6C.

Therefore, when the spiral coil portion is formed next time, the curvature of the coil, which should be formed in a spiral shape, is locally deformed in the above-mentioned bending portion Gj, and the spring function of the spiral spring is deteriorated. It was

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to form a winding hook retaining portion having a "" shape from a winding start to a winding end. In the meantime, it is an object of the present invention to provide a method for forming a spiral spring in which the wire rod drawn out from the wire guide is held in a substantially straight line so that the above-mentioned bent portion is not formed in the wire rod near the outlet of the wire guide. .

[0006]

In order to achieve the above-mentioned object, a method for forming a spiral spring according to the present invention comprises a wire rod extending in front of a wire guide and a groove formed in one end of a core winding tool. After pinching the tip of the wire rod, the feeding of the wire rod is stopped, the core winding tool is rotated to wind the wire rod along the outer periphery thereof, and the bent portion of the winding end and the wire guide are wound. In order to hold the wire drawn from the wire rod in a substantially straight line, the core winding tool is sequentially moved in a direction perpendicular to the wire drawn from the wire guide to form the wire into a "-" shaped winding core hooking portion. , After retracting the core winding tool from the core retaining portion so as to be separated from the core retaining portion, a spiral tool is brought into contact with the outer periphery of the core retaining portion, and a wire rod following the core retaining portion is attached. Move it forward and make it collide with the spiral tool, Rear end of the wire rod by forming a spiral coil part with a predetermined number of turns continuous to the section, abutting the cutting die at a predetermined position of the wire rod that follows from the spiral coil part, and advancing the cutting punch from the direction facing the cutting die. Is cut to form a spiral spring.

Further, a rear end portion of the wire rod which follows the spiral coil portion is a rear end retaining portion having a bent portion for retaining, and the rear end retaining portion has at least one concave molding. A bending die having a surface formed and capable of advancing and retreating simultaneously with the cutting die, and a bending die having at least one convex forming surface formed and capable of advancing and retracting simultaneously with the cutting punch are provided, and the concave shape of the bending die is formed substantially at the same time as the cutting of the wire. The wire rod 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.

The wire rod formed into the spiral spring can also be formed into a plate-like wire rod.

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

At the same time as cutting the wire rod, the wire rod is sandwiched and pressed by the concave molding surface of the bending die and the convex molding surface of the bending punch to form a bent portion for hooking at the rear end hooking portion. By doing so, the spiral spring having the core retaining portion and the rear end retaining portion can be continuously formed automatically.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for forming a spiral spring, which is a first example of the present invention, will be described below with reference to FIGS.

FIG. 1 and FIG. 2 are views of the winding core hooking portion shown in FIG.
It is explanatory drawing which shows the form of shaping | molding from just before the winding start shown in (a) (winding angle is 0 degree) to the winding end shown in FIG.2 (c) (winding angle is 360 degrees), A tool for forming the spiral coil portion and cutting the rear end portion is omitted, and FIG.
The feed roller is omitted in FIGS. 2B and 2C and FIGS. 2B and 2C.

Further, the pair of feed rollers 1A and 1B are configured to be rotatable and capable of performing arbitrary positioning control of a rotation angle. Further, the wire guide 2 is formed with a wire rod guide groove 2a so that the wire rod S can be moved only in the lateral direction shown in the figure.
Further, the core winding tool 3 includes a notch groove 3a in which the wire S can be inserted at one end of the cylindrical body at right angles to the axis, and one end portion of the notch groove 3a on the rear side in the counterclockwise direction. A semi-circular corner 3b is formed, and is rotatable about an axis, and
Arbitrary positioning control of the rotation angle is possible.
The winding angle at the end of winding of the core hooking portion shown in FIG. 2C of this example is 360 °, but in the range of about 300 ° to about 400 ° from the beginning of winding, The coil forming of the next spiral coil portion is possible.

FIG. 3 is an explanatory view showing the form of the spiral coil portion immediately before the start of coil forming shown in FIG. 3 (a) and immediately before the end of coil forming shown in FIG. 3 (b). The tools for forming and cutting the rear end are omitted in the drawing. The spiral tools 4 and 4 are attached to the tool holder 9 with a predetermined distance therebetween, and the tool holder 9 can move forward in the direction of the diagonally upward right arrow and can retract in the direction of the diagonally downward left arrow. In addition, it is configured to allow arbitrary positioning control. Although the two spiral tools 4 and 4 are illustrated, when the spiral coil portion to be molded has a large coil diameter, the spiral tools may be molded using three or more spiral tools.

FIG. 4 is an explanatory view showing the form immediately after cutting the rear end portion, and the tools for forming the core retaining portion and the spiral coil portion are omitted. Also, the cutting die 5
Has a cutting edge formed at the upper left corner and a left side surface that is vertically movable below the front end surface of the line guide 2 on the left side. Further, 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 a right side surface of the cutting blade is close to or slides on a left side surface of the cutting die 5.

In the method for forming the spiral spring of the first example, the core retaining portion is first formed, then the spiral coil portion is formed, and finally the rear end is cut to form the spiral spring. To do.

First of all, when molding the retaining portion of the winding core, as shown in FIG.
As shown in (a), the pair of feed rollers 1A and 1B are respectively brought into contact with the wire rod S to sandwich the wire rod S between the feed rollers 1A and 1B, and the feed roller 1A is moved in the direction of a clockwise arrow 1B. Rotate counterclockwise in the directions of the arrows.

Then, the wire rod S sandwiched between the feed rollers 1A and 1B is forwardly extended from the wire rod guide groove 2a of the line guide 2, and is substantially in a straight line with the wire rod S delivered from the line guide 2 (that is, it is paid out from the line guide 2). The tip end portion of the wire rod 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 rod S and the core winding tool 3 described later) and stands by in front of the wire guide 2. After that, the feed roller 1
As shown by the two-dot chain line, A and 1B are respectively moved in the directions away from the wire S, and the clamping and rotation of the wire S by the feed rollers 1A and 1B are released.

Next, as shown in FIG. 1B, the core winding tool 3 is rotated in the direction of the counterclockwise 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 pulling the wire rod 2 from the wire guide 2 in the direction of the left arrow, the wire S is wound along the semicircular corner 3b of the core winding tool 3, and a bent portion Fb formed by the semicircular corner 3b of the core winding tool 3 is formed. In order to hold the wire rod S drawn from the wire guide 2 in a substantially straight line, the core winding tool 3 is sequentially lowered in the direction of the downward arrow (the direction perpendicular to the wire rod S drawn from the wire guide 2) to move from the wire guide 2. The center distance Lb between the drawn wire rod S and the core winding tool 3 is displaced. here,
A straight line portion “F” shaped like “” at the tip of the bent portion Fb
a is formed.

Then, as shown in FIG. 1 (c), the core winding tool 3 is successively rotated in the same direction, and the wire rod S is pulled out from the wire guide 2, while the semi-circular corner 3b of the core winding tool 3 is drawn.
Wire rod S is wound from the outer periphery toward the outer periphery to form a bent portion Fb, and the core winding tool 3 is continuously and sequentially moved in the same direction in order to hold the bent portion Fb and the wire rod S drawn from the wire guide 2 in a substantially straight line. The center distance Lc between the wire rod S pulled down from the wire guide 2 and the core winding tool 3
Is displaced.

Next, as shown in FIG. 2 (a), the core winding tool 3 is continuously rotated in the same direction to pull out the wire rod S from the wire guide 2, and the wire rod S along the outer circumference of the core winding tool 3. The core winding tool 3 is successively lowered in the same direction in order to hold the bent portion Fc of the winding end and the wire S drawn from the wire guide 2 in a substantially straight line while winding the wire. Wire rod S and core winding tool 3 that are pulled out
The center distance Ld between and is displaced.

After the wire S comes into contact with the core winding tool 3 along the outer periphery with a constant radius, the radius of the bent portion Fc from the center of rotation to the winding end is constant, so that the winding end is bent. Part F
c and the wire rod S drawn from the wire guide 2 can be held in a substantially straight line at the center of rotation of the core winding tool 3, so that the wire rod S abuts along the outer circumference of the core winding tool 3 with a constant radius. After that, in order not to displace the center distance Ld between the wire rod S drawn out from the wire guide 2 and the core winding tool 3,
The descent of the core winding tool 3 is stopped, and this stop position is maintained.

Then, as shown in FIG. 2 (b), the core winding tool 3 is continuously rotated in the same direction to pull out the wire rod S from the wire guide 2, and the wire rod S is wound along the outer periphery of the core winding tool 3. To wind. The center distance between the wire rod S and the core winding tool 3 is Le = Ld because it is not displaced from the state shown in FIG.

Then, as shown in FIG. 2 (c), the core winding tool 3 is rotated counterclockwise from the winding start in FIG. 1 (a) in the direction of the arrow to position and stop at the 360 ° position. By doing so, the winding core hooking portion F having the shape of a "no" is formed. In this state, a spring back acts on the core hooking portion F in the direction of the clockwise arrow opposite to the winding direction, and the core hooking portion F turns the engaging portion with the core winding tool 3 clockwise. Press in the direction of the arrow,
When the core winding tool 3 retreats in the direction of the axis of rotation, which will be described later, the core winding tool 3 may pull the core hooking portion F in the retreating direction, or the core winding tool 3 may not smoothly move backward. easy.

In order to prevent this phenomenon, the core winding tool 3
After stopping the positioning at a position rotated 360 ° in the counterclockwise direction from the start of winding, the core winding tool 3 is moved in the clockwise direction from the 360 ° position by the amount of the action of the spring back described above. Rotate. Then, in order to separate the core winding tool 3 from the core retaining 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 of the next work is hooked. In preparation for forming the stopper 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 rod S and the core winding tool 3 is shown in FIG.
Since it is not displaced from the state shown in (3), Lf = Le.

In forming the next spiral coil portion, as shown in FIG.
As shown in (a), the feed rollers 1A and 1B, which were separated from the wire rod S at the time of forming the above-described winding-core hooking portion F, are brought into contact with the wire rod S, and the wire rod S is moved by the feed rollers 1A and 1B. While nipping, the feed roller 1A is rotated in the direction of the counterclockwise arrow and 1B is rotated in the direction of the clockwise arrow.

Then, the wire S sandwiched between the feed rollers 1A and 1B is returned in the direction of the arrow pointing to the right, and the core locking portion F is obtained.
Position the winding end Fc of the wire guide 2 in the vicinity of the front end of the wire guide 2 and move the tool holder 9 forward in the direction of the diagonally right upward arrow 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 winding core stop F.

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

However, when the wire S sandwiched by the feed rollers 1A and 1B is fed out from the wire guide groove 2a of the wire guide 2 for a predetermined length, and then the rotation of the feed rollers 1A and 1B is stopped, a spiral coil portion with a predetermined number of turns is formed. C is formed. Then, in order to separate the spiral tools 4 and 4 from the spiral coil portion C in preparation for the next cutting of the rear end portion R, the spiral tools 4 and 4 are retracted in the direction of the diagonally left downward arrow to be separated, and at the retracted end. In order to move the rear end of the rear end portion R, which is continuous with the spiral coil portion C, to the cutting position while waiting, the feed roller 1A holding the wire rod S in the clockwise arrow direction and 1B in the counterclockwise arrow direction. The wire rod S is fed out and the rear end of the rear end portion R is positioned at the 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 to position it at a position where the wire rod S is sandwiched between the upper end surface and the lower surface of the front end cutout portion of the wire guide 2. . Then, the cutting punch 6 is lowered to bring the lower end surface into contact with the wire rod S of the rear end portion R, and after the contact, the cutting punch 6 is continuously lowered, whereby the cutting formed at the upper left corner of the cutting die 5. 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 the usual spiral spring is used by hooking the winding core portion of the spiral coil and the rear end portion outside the spiral coil, in this case, the spiral spring formed as described above is used. On the rear end portion R of W, a hooking portion is formed by a pressing machine or the like.
With such a molding method, the production efficiency is low and the manufacturing cost is high. Therefore, if the molding is performed in the same step as the cutting of the rear end portion of the present invention described below, the production efficiency can be improved and the manufacturing cost can be reduced.

Next, the second embodiment of the present invention, which is a second embodiment of the method for forming a spiral spring with a rear end retaining portion having a bent portion for retaining at the rear end portion, will be described below with reference to FIG. Explain as follows.

FIG. 5 is an explanatory view showing a form immediately after bending for cutting and hooking the rear end of the rear end hooking portion,
The tools for forming the core retaining portion and the spiral coil portion are omitted in the drawing. Further, the cutting die 5 and the cutting punch 6 have the same configurations as those described with reference to FIG. Further, the bending die 7 has a concave-convex shaped surface 7 a formed on the upper surface thereof, and the upper end surface is substantially flush with the upper end surface of the cutting die 5.
Is attached to the left side of the. Further, the bending punch 8 has a convex molding surface 8a formed at the lower end thereof, and the convex molding surface 8a is engaged with the concave portion of the concave-convex molding surface 7a with the wire S sandwiched therebetween. It is attached to the surface.

In the second example of the method for forming the spiral spring with the rear end hooking portion, first, the core hooking portion is formed, then the spiral coil portion is formed, and finally the rear end hooking portion is formed. A spiral spring with a rear end retaining portion is formed by cutting an end and forming a bent portion for retaining the rear end retaining portion. Since the molding of the first winding core hooking portion and the molding of the subsequent spiral coil portion are the same as the molding method of the first example, the description thereof is omitted, and the spiral coil portion is molded. After that, in preparation for the cutting of the next rear end, the spiral tool is waited at the backward end, and the rear end of the rear end is described as being positioned at the cutting position on the left side surface of the cutting die 5 described later.

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

Even after the contact, when the bending punch 8 is continuously lowered together with the cutting punch 6, the cutting blade formed at the upper left corner of the cutting die 5 and the right lower corner of the cutting punch 6 are formed. The cutting edge cuts the rear end of the rear end hooking portion H, and the uneven molding surface 7 formed on the bending die 7
a and the convex forming surface 8a formed on the bending punch 8 sandwich and press the rear end retaining portion H, and the bent portion Ha is bent and formed into a corrugated shape, and the spiral spring with the rear end retaining portion is formed. Wr is completed.

The material of the spiral spring and the spiral spring with the rear end retaining portion formed according to the present invention may be a wire rod,
Alternatively, even a plate material can be molded by the above-mentioned molding method if the cross-sectional shape of each tool to be used can be engaged with the shape of the wire material or the plate material.

[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 from the wire guide in a substantially straight line from the beginning of winding to the winding end of forming the "-"-shaped winding core hooking portion, Since the core winding tool is sequentially moved in the direction perpendicular to the wire rod, an unnecessary bending portion is not formed in the wire rod near the exit of the wire guide unlike the prior art. However, when the spiral coil portion is formed next time, there is no local deformation of the coil curvature, and a spiral spring having a high spring function can be formed.

Further, when forming the spiral spring with the rear end hooking portion, since the bent portion for hooking can be formed in the rear end hooking portion in the same step as the cutting of the rear end, the production efficiency can be improved. It is possible to improve and reduce the manufacturing cost.

[Brief description of drawings]

1A and 1B are explanatory views showing an embodiment of molding of a core retaining portion according to the present invention, in which (a) has a winding angle of 0 °, (b) has a rotation angle of 45 °, and (c) has a rotation angle of 90 °. It is a vertical cross-sectional view of °.

FIG. 2 is an explanatory view showing an embodiment of molding of a core retaining portion according to the present invention, in which (a) shows a winding angle of 180 ° and (b) shows
Is a vertical sectional view of the same 220 °, and FIG.

FIG. 3 is an explanatory view showing an embodiment of spiral coil part molding according to the present invention, in which (a) is a longitudinal sectional view before molding and (b) is a longitudinal sectional view after molding.

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

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

6 (a) and 6 (b) are explanatory views showing a form of forming a core retaining portion according to a conventional technique, in which (a) shows a winding angle of 0 °, (b) shows a winding angle of 360 °, and (c) shows a winding core. It is a longitudinal cross-sectional view of a state in which the core winding tool is retracted after forming the hook portion.

[Explanation 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 stop part Fc Core core hook Stop part Bent part of winding end H Rear end hooking part La to Lf Center distance between wire rod and core winding tool S Wire rod R Rear end part W Swirl spring Wr Spiral spring with rear end hooking part

Claims (3)

[Claims] 1. A wire rod is inserted into a notch groove of a core winding tool to rotate the core winding tool, and a wire rod following the wire is wound around the outer periphery of the core winding tool to form a "no" shape. A predetermined shape is formed in the core retaining portion, a spiral tool is brought into contact with the outer periphery of the core retaining portion, and a wire rod that follows from the core retaining portion is forwarded to collide with the spiral tool. Formed into a spiral coil portion having the number of turns, a cutting die is brought into contact with a predetermined position of the wire rod that follows from the spiral coil portion, and a cutting punch is advanced from a direction facing the cutting die to cut the rear end of the wire rod. A method for forming a spiral spring, comprising: forming a wire rod in front of a wire guide; inserting a tip end portion of the wire rod into a notch groove formed at one end of a core winding tool; The feeding is stopped, the core winding tool is rotated, and the wire rod is wound along the outer periphery thereof. While winding, in order to hold the bent portion of the winding end and the wire drawn out from the wire guide in a substantially straight line, the core winding tool is sequentially moved in a direction perpendicular to the wire drawn out from the wire guide Is formed into a "-" shaped core retaining portion, the core winding tool is retracted to separate from the core retaining portion, and then a spiral coil portion continuous with the core retaining portion is formed. A method for forming a spiral spring, characterized in that the spiral spring is formed by cutting the rear end and the rear end. 2. The rear end portion of the wire rod that follows the spiral coil portion according to claim 1 is a rear end hook portion having a bent portion for hooking, and the rear end hook portion includes: A cutting die for forming at least one concave molding surface and capable of advancing and retreating simultaneously with a cutting die; and a bending punch for forming at least one convex molding surface capable of advancing and retracting at the same time as a cutting punch. A wire rod is sandwiched and pressed by the concave molding surface of the bending die and the convex molding surface of the bending punch substantially at the same time to form a bent portion for hooking at the rear end hooking portion. A method for forming a spiral spring according to. 3. The method for forming a spiral spring according to claim 1, wherein the wire formed in the spiral spring is a plate-shaped wire.