JPH10216879A - Manufacture of spiral spring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a spiral spring having a spiral body part and a J- shaped inner hook part without any increase of manufacturing man-hour required. SOLUTION: A cylindrical spindle 5 with wire feed inlet 17 is arranged rotatably. Inside the spindle 5, a core bar 6 is arranged nonrotatably and separately. A long strip of wire 12 of almost uniform section is feed toward the rotary center C of the spindle 5. The tip 12a of the wire 12 is let into the spindle 5 through the wire feed inlet 17. On the state making the tip 12a abut on the core bar 6, the wire feed inlet 17 is displaced by rotating the spindle 5. Then, the tip 12a is held between the spindle 5 and core bar 6, is folded back almost in J-shape, and thus inner hook portion is formed. Further, the part of wire 12 following the tip 12a is wound on the outer surface 15b of the spindle 5 and the body part is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a spiral spring, and more particularly, to a spiral having an inner hook portion at an inner end of a spiral main body using an elongated plate-like wire having a substantially uniform cross section. The present invention relates to a method for manufacturing a spring.

[0002]

2. Description of the Related Art Conventionally, for example, a spiral spring having relatively high elasticity has been employed in a reclining mechanism for a backrest in an automobile seat, a window glass opening / closing mechanism in an automobile door, and the like. As shown in FIG. 5, a spiral spring of this type includes a spiral main body 51, an inner hook portion 53 formed at an inner end 51a thereof toward a central portion O of the spiral spring 52, and a main body 51. In general, the outer hook 51 has an outer hook portion 54 folded back at the outer end 51b. The inner hook portion 53 and the outer hook portion 54 are portions for locking the spiral spring 52 to a reclining mechanism or the like.

A spiral spring 52 of the above type is shown in FIG.
As shown in FIG. 5, an elongated plate-shaped wire 55 having a substantially uniform cross section,
A substantially cylindrical core bar 57 having a small diameter and a slit 56
It is manufactured as follows using these. The wire 55 is directed toward the rotation center C of the core bar 57, that is, FIG.
Is supplied from the right to the left. The tip 55 a of the wire 55 is inserted into the slit 56. The core metal 57 is shown in FIG.
As shown in FIG. 6B, the wire 55 rotates in the counterclockwise direction of FIG.
The part following a is wound around the core bar 57 several times,
Spiraled. After that, the wire 55 is cut by the lower cutting die 58 and the cutting blade 59. The rear end portion 55 b of the wire 55 is bent by the curved mold 60 and the curved mold 61. The spiral spring 52 having a desired shape is formed on the metal core 57.

In recent years, the spiral spring 5 described above has been used.
The type in which the central portion of 2 is omitted and the overall length is shortened has also been adopted. In this spiral spring, the main body 51 has a relatively large diameter, and the inner hook portion 62 is folded in a substantially J-shape as shown by a two-dot chain line in FIG.

[0005]

However, according to the above-described method, the former spiral spring 52 can be manufactured, but the latter spiral spring cannot be manufactured. This is due to the difference in the bending angles of the inner hook portions 53 and 62. That is, in the above-described manufacturing apparatus, since the wire 55 is supplied toward the rotation center C of the core bar 57, the slit 56 into which the distal end portion 55a of the wire 55 is inserted also naturally has the rotation center of the core bar 57. It will be formed at a position passing through C. This means that the inner hook portion 53 formed by the above-described method is positioned at the rotation center C of the metal core 57 (the center of the main body 51).
It means that it is limited to what extends toward. Therefore, in order to manufacture the latter spiral spring using the above-described apparatus and method, the end of the wire 55 is once bent toward the rotation center C, and then, using another apparatus, The end will be bent further deeply. In this case, a bending step is required in addition to the conventional manufacturing steps, and the number of manufacturing steps is increased.

It is an object of the present invention to provide a method for manufacturing a spiral spring having a spiral main body and a substantially J-shaped inner hook without increasing the number of manufacturing steps.

[0007]

According to a first aspect of the present invention, there is provided a cylindrical member having a cylindrical peripheral wall portion and a wire supply port opened in a part of the peripheral wall portion. The spindle is rotatably arranged on the wire supply path,
The rotation of the spindle is stopped with the wire supply port aligned with the supply path, and the leading end of the wire conveyed along the supply path is inserted into the spindle through the wire supply port. By rotating the spindle in a state where the tip portion is in contact with the core bar arranged in the above, the tip portion is sandwiched between the spindle and the core bar and turned into a substantially J-shape to form the inner hook portion. The portion following the tip portion is wound around the outer peripheral surface of the spindle to form the main body.

According to the first aspect of the invention, when manufacturing the spiral spring, the rotation of the spindle is temporarily stopped while the wire supply port is aligned with the supply path. The leading end of the wire conveyed along the supply path enters the spindle through the wire supply port. The spindle rotates, and the position of the wire supply port changes accordingly. Due to this change, stress is applied to a portion of the wire located at the wire supply port, and the tip of the wire is bent using the portion as a fulcrum.
At this time, the front end portion of the wire is sandwiched between the spindle and the metal core, and is folded back into a substantially J shape. This folded portion becomes an inner hook portion. In addition, the rotation of the spindle causes a portion following the leading end of the wire to be wound around the outer peripheral surface of the spindle. This wound portion becomes the main body. In this manner, the tip portion of the wire is folded at one time (deeply bent) with the rotation of the spindle to form an inner hook portion.

[0009] The second invention described in claim 2 is the first invention.
In addition to the invention, the core metal is formed in a substantially semi-cylindrical shape, and,
The outer peripheral surface is arranged so as to be located at a position slightly larger than the thickness of the wire rod from the inner peripheral surface of the spindle, and at the time of forming the inner hook portion, a predetermined angle after the spindle starts rotating. During the period until the rotation, the distal end portion of the wire is sandwiched between the outer peripheral surface of the cored bar and the inner peripheral surface of the spindle, and is held in a folded state.

According to the second aspect of the present invention, during a period from the start of rotation of the spindle to the rotation of the spindle by a predetermined angle, the leading end of the wire is sandwiched between the outer peripheral surface of the cored bar and the inner peripheral surface of the spindle. It is. During this period, the tip portion is held in a state of being folded back into a J-shape.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

First, a spiral spring to which the manufacturing method of this embodiment is applied will be described. The spiral spring is made of an elongated plate-shaped hard pressure wire having a substantially uniform cross section, and is used for a reclining mechanism of a backrest in an automobile seat, a window glass opening and closing mechanism in an automobile door, and the like. As shown in FIG.
Is a main body 2 spirally wound on the same plane,
An inner hook 3 is formed at the inner end 2a, and an outer hook 4 is formed at the outer end 2b of the main body 2. While the inner end 51a of the main body 51 in the conventional spiral spring 52 is located at the center O of the spiral spring 52, the inner end 2a of the spiral spring 1 according to the present embodiment is It is located at a position deviated from the central portion O. In other words, the main body 2 does not exist in the central portion of the spiral spring 1 and the central portion is hollow. Therefore, the main body 2 has no small radius of curvature and has a large radius of curvature as a whole.

The inner hook portion 3 and the outer hook portion 4 are portions where the spiral spring 1 is locked to a reclining mechanism or an opening / closing mechanism. For example, when the spiral spring 1 is employed in a reclining mechanism, the inner hook portion 3 is locked on the seat portion side, and the outer hook portion 4 is locked on the backrest side. The inner hook portion 3 is folded in a substantially J shape inward from the inner end 2a. The outer hook portion 4 is bent outward from the outer end 2b of the main body portion 2 in a substantially J-shape.

In manufacturing the spiral spring 1 having the above structure,
As shown in FIGS. 1 and 4, a manufacturing process including a spindle 5, a cored bar 6, a press roller 7, a lower cutting die 8, a cutting blade 9, a curved lower mold 10, a curved upper mold 11, and a wire rod supply mechanism (not shown). A device is used. The wire rod supply mechanism moves the wire rod 12 to the position shown in FIG.
This is a mechanism for forcibly sending out from the right side to the left side, and includes a motor, a feed roller, and the like (these are not shown).

The spindle 5 has a supply path 13 for the wire 12.
Above, it is provided so as to be rotatable in the counterclockwise direction in FIG. As shown in FIG. 4, the spindle 5 includes a cylindrical shaft portion 14 and a spindle main body 15 provided integrally with the distal end thereof and having a substantially cylindrical shape with a bottom. A slit-shaped wire supply port 17 extending in the radial direction is formed in the peripheral wall portion 16 of the spindle body 15. Most of the peripheral wall portion 16 has a substantially constant thickness, but the portion near the wire supply port 17 and on the front side in the rotation direction of the spindle 5 increases in thickness as approaching the wire supply port 17. Is set to A portion in the vicinity of the wire supply port 17 of the peripheral wall portion 16 on the rear side in the rotation direction of the spindle 5 is chamfered and formed into a curved surface. This portion is hereinafter referred to as a curved surface portion 16a.

The metal core 6 comprises a base 18, a disk 19 and a metal core body 20. The base 18 has a square plate shape, and is reciprocated in a direction approaching and leaving the spindle 5. The core 6 does not rotate unlike the spindle 5. The disk 19 is provided integrally with the tip of the base 18. The core metal body 20 has a substantially semi-cylindrical shape, and has a curved outer peripheral surface 20a and a planar engagement surface 20b. The core metal body 20 is provided integrally with the distal end surface of the disk portion 19 at a position slightly deviated from the center thereof. The core metal body 20
As it approaches the spindle 5, it enters the spindle body 15. In this state, the outer peripheral surface 20
a is separated from the inner peripheral surface 15a of the spindle body 15. The distance between the two 15 and 20a is substantially constant (slightly wider than the thickness of the wire 12) at any point. Also,
The engaging surface 20b of the cored metal body 20 is located at a position slightly deviated from the rotation center C of the spindle 5.

As shown in FIG. 1A, the pressing roller 7 and the lower cutting die 8 are disposed at a position behind the spindle 5 on the supply path 13 and are vertically separated from each other. The cutting blade 9 is arranged so as to be able to reciprocate up and down in front of the pressing roller 7, and cuts the wire rod 12 in cooperation with the lower cutting die 8 when moved down.
The curved lower die 10 is fixed between the spindle 5 and the lower cutting die 8, and the curved upper die 11 is arranged so as to be vertically reciprocable between the spindle 5 and the cutting blade 9. The curved mold 11 is
The wire rod 12 is bent in cooperation with the lower bending die 10.

Next, a method of manufacturing the spiral spring 1 from the wire 12 using the above-described apparatus will be described. First, FIG.
As shown in (a), the rotation of the spindle 5 is stopped so that the wire supply port 17 coincides with the supply path 13 of the wire 12. The mandrel 6 is moved to the spindle 5 side, and the mandrel main body 20 is inserted into the spindle main body 15. The engagement surface 20 b of the cored metal body 20 is located on the supply path 13. The opening of the spindle body 15 is
Will be in a closed state. Further, both the cutting blade 9 and the curving die 11 are moved upward to retreat from the supply path 13.

The wire 12 is supplied (conveyed) from the right to the left (the rotation center C of the spindle 5) in FIG. By the supply, the tip portion 12 a of the wire 12 enters the spindle main body 15 through the wire supply port 17. When the distal end portion 12a enters a predetermined length (this length is determined by the shape of the inner hook portion 3), the supply of the wire 12 is temporarily stopped. The spindle 5 is rotated with the core 6 stopped. With this rotation, the position of the wire supply port 17 changes. The wire 12 is supplied by the rotation of the spindle 5.

Due to the displacement of the wire supply port 17, the curved surface portion 16a comes into contact with a portion 12b of the wire 12 located at the wire supply port 17, and a stress is applied to the location 12b from below. At this time, the pressing roller 7 is in contact with a portion of the wire 12 located outside the spindle 5. For this reason, the portion of the wire 12 in front of the pressing roller 7 is pushed up, and the tip of the wire 12 is
0c. Further, when the spindle 5 rotates,
The upward movement of the wire 12 is caused by the pressing roller 7 and the core metal body 2.
Since it is regulated by 0, the tip portion 12a of the wire 12 is bent with the contact point with the curved surface portion 16a as a fulcrum.

As the rotation of the spindle 5 proceeds, the wire 1
The second tip portion 12a is automatically turned back toward the curved surface portion 16a. Accordingly, the contact portion of the tip portion 12a with the core metal body 20 shifts from the corner portion 20c to the outer peripheral surface 20a side. Eventually, as shown in FIG. 1B (b), the distal end portion 12a is sandwiched between the curved surface portion 16a of the spindle 5 and the outer peripheral surface 20a of the cored metal body 20. The tip portion 12a has a shape corresponding to the curved surface portion 16a, that is, a substantially J-shape.

As shown in FIG. 2A, during the period from the start of rotation of the spindle 5 to the rotation of a predetermined angle (approximately 180 degrees when the core metal body is semi-cylindrical), the outer peripheral surface 20a The tip portion 12a continues to be sandwiched between the inner peripheral surface 15a and the inner peripheral surface 15a. In this period, the tip portion 12a
Is held in a state of being folded back in a J-shape. When the spindle 5 is further rotated, the distal end portion 12a is disengaged from the cored bar main body 20, and is displaced while being in close contact with the curved surface portion 16a.

On the other hand, with the rotation of the spindle 5, the portion following the tip portion 12a of the wire 12 is
5 is wound around the outer peripheral surface 15b. As the rotation of the spindle 5 progresses, the wire 12 is sequentially spirally wound.
When the spindle 5 rotates a plurality of times, the rotation is stopped and the supply of the wire 12 is stopped, and the cutting blade 9 is moved downward and upward as shown in FIG. Cutting blade 9
The wire rod 12 is cut by the cutting base 8. After that, the curved die 11 is moved down and up. Then wire 1
The rear end portion 12c is bent into a substantially J-shape by the curved mold 11 and the curved mold 10.

Subsequently, the mandrel 6 is withdrawn and the mandrel main body 20 is extracted from the spindle body 15. Then, the wire 12 wound around the spindle body 15 is removed. Then, a spiral spring 1 having a desired shape, having the main body 2, the inner hook 3, and the outer hook 4, is obtained. By the series of operations described above, the process for manufacturing one spiral spring 1 is completed. By repeating this process, the spiral spring 1 is manufactured continuously.

As described above, according to the manufacturing method, the inner hook portion 3 is formed by using the spindle 5 and the cored bar 6 to turn the distal end portion 12a of the wire 12 at one time with the rotation of the spindle 5. At the same time, the portion following the tip portion 12a can be wound around the spindle 5 to form the spiral main body 2. For this reason, the spiral spring 1 having the substantially J-shaped inner hook portion 3 is manufactured without increasing the number of manufacturing steps as compared with the related art in which the tip portion 55a of the wire 55 is bent twice to form the inner hook portion 62. can do.

This embodiment has the following features in addition to the items described above.

(A) The end of the wire 12 can be held in a folded state over a period until the spindle 5 rotates by a predetermined angle, and the folded portion is deformed when the wire 12 is wound around the spindle 5 (spindle 5). To the rotation center C side) can be prevented.

(B) If a plurality of types of the spindle 5 and the cored bar 6 are prepared in advance, various spiral springs 1 having different diameters and different numbers of turns can be manufactured only by changing these.
It is not necessary to modify other parts or add another part. The conventional manufacturing apparatus can be directly used for manufacturing the spiral spring 1 of the present embodiment.
In other words, it is possible to cope with the manufacture of a plurality of types of spiral springs 1 by the existing manufacturing apparatus. This leads to a reduction in manufacturing costs. Furthermore, different types of spiral springs 1
, It is only necessary to replace the spindle 5 and the cored bar 6 corresponding thereto. For this reason, the time required for switching can be reduced, and this is effective in increasing the efficiency of manufacturing (setup).

(C) In a series of operations such as supply of the wire 12, rotation of the spindle 5, vertical movement of the cutting blade 9, and vertical movement of the curved die 11, the inner hook portion 3, The main body 2 and the outer hook 4 can be formed automatically. For this reason, the manufacturing method of the present embodiment uses the spiral spring 1
It is also effective in accelerating the automation of the production of pulp.

The present invention is not limited to the above embodiment, but may be modified as follows. The tip end portion 12a of the wire 12 that has entered the spindle 5 comes into contact with the cored bar main body 20 and the tip end portion 12a that is separated from the inner peripheral surface 15a of the spindle body 15 and that is early in the rotation of the spindle 5. It is necessary to have a contact point. Therefore, under the condition that these portions are provided, the core metal body 20 may be changed to a shape different from that of the above-described embodiment.

[0031]

As described above, according to the first aspect, the end portion of the wire can be folded at one time to form a substantially J-shaped inner hook portion. A spiral spring having a main body portion and an inner hook portion can be reliably manufactured without increasing the number of manufacturing steps.

According to the second aspect, in addition to the effects of the first aspect, the end of the wire can be held in a folded state over a period until the spindle rotates by a predetermined angle, and when the wire is wound around the spindle, The folded part can be prevented from being deformed.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are explanatory views showing a manufacturing process of a spiral spring according to an embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are explanatory views showing a manufacturing process of a spiral spring.

FIG. 3 is a front view of a spiral spring.

FIG. 4 is a partial perspective view of a spindle and a core used for manufacturing a spiral spring.

FIG. 5 is a front view of a conventional spiral spring.

6 (a) and 6 (b) are explanatory views showing steps of manufacturing the spiral spring shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spiral spring 2 Main part 2a Inner end of main part 3 Inner hook part 5 Spindle 6 Core metal 12 Wire 12a Tip of wire 12b Location corresponding to wire feed port 15a Inner circumferential surface of spindle body 15b Outer circumference of spindle body Surface 17 Wire supply port 20a Outer surface of core metal body C Spindle rotation center

Claims (2)

[Claims] An elongated plate-like wire having a substantially uniform cross section is used,
A method of manufacturing a spiral spring having a spiral main body portion and a substantially J-shaped inner hook portion located at an inner end of the main body portion, comprising: a cylindrical peripheral wall portion; and a part of the peripheral wall portion. A spindle having a wire supply port that is open to a spindle is rotatably arranged on the supply path of the wire, and the spindle is stopped rotating with the wire supply port aligned with the supply path, and the supply path is The tip portion of the wire conveyed along the wire is introduced into the spindle through the wire feed port, and then the spindle is rotated while the tip portion is in contact with a metal core arranged in the spindle. The tip portion is sandwiched between a spindle and a metal core and folded back in a substantially J-shape to form the inner hook portion, and a portion following the tip portion is wound around the outer peripheral surface of the spindle to form the main body portion. A method for manufacturing a spiral spring. 2. The core metal is formed in a substantially semi-cylindrical shape, and
The outer peripheral surface is arranged so as to be located at a position slightly larger than the thickness of the wire rod from the inner peripheral surface of the spindle, and at the time of forming the inner hook portion, a predetermined angle after the spindle starts rotating. 2. The wire according to claim 1, wherein the leading end of the wire is sandwiched between the outer peripheral surface of the cored bar and the inner peripheral surface of the spindle for a period up to rotation, and is held in a folded state. Manufacturing method of spiral spring.