JPS63190919A - Grooved screw part and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a threaded component with a groove such as a cam bolt with a groove for adjusting camber, toe-in, etc. used in a front suspension arm for an automobile, and a method for manufacturing the same.

(Prior art) Cam bolts with grooves for adjusting camber, toe-in, etc. used in automobile front suspension arms have a cam flange on the back of the bolt head, and a cam plate with the same shape as the cam flange on the threaded part. It is constructed by fastening and is used to adjust angles such as toe-in and camber.

Conventionally, this type of grooved bolt has been manufactured by a thread rolling method. In this case, first, the heading method (cold forging)
to form a head on the processed material (round bar), then form a threaded part on the processed material using a thread rolling device, and then form a rotation stopper groove in the threaded part along the axial direction. and went on.

(Problems to be Solved by the Invention) The above-mentioned anti-rotation grooves are processed by cutting using, for example, a milling cutter. In this case, a large number of milling machines and the like are required, resulting in a problem of high equipment cost, and furthermore, there is a problem of severe damage to the cutter.

In addition, since burr occurs after cutting the groove for preventing rotation, it is necessary to cut the burr by passing the threaded part through a round die for removing burr as a finishing process. There was a problem in that it required special machinery and equipment, and the equipment cost increased.

Furthermore, there is a problem in that processing costs increase because not only cutting processing requires equipment costs, but also finishing processing equipment costs.

Furthermore, there were other problems such as poor screw precision and high defect rate.

Therefore, the present invention has been made to solve the problems of the above-mentioned prior art, and its purpose is to reduce the processing time and eliminate problems such as damage to the cutter. Furthermore, it is an object of the present invention to provide a grooved screw component that can omit the deburring process, reduce equipment costs, and reduce processing costs, and that also has good screw precision and a low defect rate, and a method for manufacturing the same. .

(Means for Solving the Problems) In order to achieve the above object, a threaded component with a groove according to the present invention is provided with a threaded portion on the outer periphery of the shaft portion, and the threaded portion is located halfway from the tip of the shaft portion to the threaded portion. In addition to providing a first groove portion extending to the threaded portion, a second groove portion having the same width as the first groove portion is provided at a position axially symmetrical to the first groove portion of the threaded portion.

In addition, the manufacturing method includes providing a thread forming material having a circular cross section with a first part extending from one end of the material to a midway position of the material in the axial direction.
a groove, and a second groove having the same width as the first groove at a position axially symmetrical to the first part 1a, and then forming a circular cross-sectional part of the material in which the first and second grooves are not provided on the outer periphery of the material. A feature is that a screw is formed by rolling as a guide.

(Function) In the present invention having the above configuration, the first and second grooves are formed in the material for thread formation before thread formation, and then the thread is formed on the outer periphery of the material by rolling.

When rolling a screw, the part provided with the first and second grooves is supported in a stable rotation between the rolling dies using the circular cross-sectional part of the material without the grooves as a guide to ensure that the screw is rolled. can be formed.

On the other hand, since the first and second groove portions are formed at axially symmetrical positions and have the same width, it is possible to prevent an uneven load due to uneven contact of the die in the groove forming portion.

(Example) The present invention will be explained below based on illustrated embodiments.

First, an embodiment of the grooved screw component of the present invention will be described.

FIGS. 1(a) to 1(e) show an embodiment in which the present invention is applied to a bolt with a cam for adjusting toe-in, camber, etc. of a front suspension used in an automobile. In the same figure, reference numeral 1 is a shaft part, and a tightening head 2 is provided at one end (left side in Figure 1 (a)), and a tightening head 2 is provided at the other end (right side in Figure 1 (a)) of the shaft part 1. is provided with a threaded portion 3. The threaded portion 3 is connected to the threaded portion 3 from the tip of the shaft portion 1.
A groove 3b as a first groove for preventing rotation and having a U-shaped cross section and extending in the axial direction to an intermediate position, and an escape groove 3C as a second groove having the same width as the groove 3b and located in an axially symmetrical position with the groove 3b. is provided.

A flange cam 4 provided with an angle scale 4a (see FIG. 2B) is provided on the back surface of the head 2.

A cam plate 5 having the same shape as the flange cam 4 is attached to the threaded part 3.
(See figure (c), Ld)) - Naft (not shown)
It is concluded by. A convex portion 5b is provided on the inner periphery of the eccentric hole 5a of the cam plate 5, and the cam plate 5 is prevented from rotating by engaging the convex portion 5b with the groove portion 3b.

The cross-sectional shape of the groove 3a is not limited to a U-shaped groove, but may be formed into a U-shape, a triangle, etc., or may be flat. However, if the cross-sectional shape is U-shaped as in the embodiment, There is an effect like. In other words, in order to prevent the cam plate 5 from rotating, the surface of the threaded portion 3 may be made flat, but in this case, in order to ensure that the cam plate 5 does not rotate, a fairly large area must be flattened, and the screw If the proportion is small, sufficient fastening force cannot be obtained, and the cross-sectional area becomes small, making it impossible to secure sufficient strength against axial loads and bending loads. By making the screws into a shape, rotation can be reliably prevented even if the area is small, so the proportion occupied by the screws does not decrease too much, and the cross-sectional area does not become too small, so the necessary fastening force and strength can be secured.

Furthermore, although the cross-sectional shapes of the groove portion 3b and the relief groove 3C may be made the same, if they are made into irregular shapes as in the embodiment, the cam plate 5 will not be oriented in the wrong direction when attached, and the efficiency of the assembly work can be improved. can.

In this embodiment, the flange cam 4 is formed integrally with the shaft portion 1 of the bolt by forging. If the flange cam 4 is integrally formed by forging in this way, the flange cam 4
The relative positioning between the position of the cam face and the anti-rotation groove 3b can be performed accurately.

Therefore, the relative position of the flange cam 4 and the cam plate 5 whose rotation is prevented by the rotation prevention groove 3b can be accurately determined. In this embodiment, the top dead center position of the cam face of the flange cam 4 and the groove portion 3b are aligned.

Next, an embodiment of the method for manufacturing a grooved screw component of the present invention will be described with reference to FIGS. 2 to 5.

First, as shown in Figure 2 ta> to tc>, the heading method (
Processed material for thread formation by cold forging), 7 (round bar)
A guide portion 3a, a groove portion 3b, and an escape groove 3C are formed in the thread forming portion 8 (the portion that will become the thread portion 3 after thread rolling) by pre-processing. This heading process is normally performed as a pre-processing for thread rolling, and in the present invention, by using this heading process to also form the groove part 3b,
Cutting and deburring processes after thread rolling are omitted. The guide portion 3a and the escape groove 3C are necessary because the groove portion 3b is processed before thread rolling.

Note that the head 2 and flange cam 4 are also formed at the same time during this forging.

Here, the outer diameter of the guide portion 3a is machined to a thread-rolled diameter (a diameter smaller than the outer diameter after rolling by the height of the thread). This guide portion 3a is connected to the die 6 during thread rolling.
(See Figures 3 and 4) The part that forms the rolling axis receives uniform rolling pressure. In addition, the escape groove 3C is the groove part 3.
It is located on the side opposite to b, and its width is machined to be almost the same as the width of the groove part 3b, and its depth is machined to be the same as the height of the thread of the die 6. Therefore, no threads are formed during rolling, which is a later process.

Next, a third
As shown in the figures and FIG. 4, a thread is formed by a thread rolling method. In this step, first, the workpiece 7 is interposed between the dies 6 and 6 of the rolling device.

At this time, there is a gap between the part where the groove part 3a is formed and the die 6, but the part where the guide part 3a is formed is between the die 6.
Therefore, the thread forming portion 8 (the portion that will become the thread portion 3 after thread rolling) of the processed material 7 can be supported by the die 6.6 without any problem.

The reason for providing this guide portion 3a is as follows.

That is, since the groove portion 3a and the relief 13c are formed in advance by heading (cold forging) before rolling the screw on the threaded portion 3, when rolling the screw on the threaded portion 3, the threaded portion 3 is not rolled. Therefore, if the threaded portion 3 is provided with a guide portion 3a, the guide portion 3a will be sandwiched between the dies of the thread rolling device during thread rolling. The threaded portion 3 can now be supported by the rolling device. In this guide part 3a, when thread rolling,
A screw is formed.

Then, when the die 6.6 is rotated while applying rolling pressure to the thread forming portion 8 of the workpiece 7, the thread forming portion 8 of the workpiece 7 rolls between the dies 6.6. When the groove 3b reaches one of the dies 6, the rolling pressure becomes zero, but at this time, the relief 1 on the opposite side of the groove 3b
13c also approaches the other die 6 and the rolling pressure becomes zero in the same way, so the pressure is balanced and the thread forming part 8
(See Figure 3 (b))
.

As a result, the portions other than the groove portion 3b and relief groove 3C are subjected to rolling pressure and a complete thread is formed (see FIG. 5).

Further, the reason why the escape groove 3c is provided is as follows.

That is, during thread rolling, when the groove 3b is caught by the die 6 of the thread rolling device (see Figures 3 and 4), an uneven load is applied to the threaded portion 3, so this is to release this load. . This prevents slippage and curling during rolling, and prevents inconveniences such as failure to form threads.

By performing thread rolling in this manner, a grooved threaded component as shown in FIG. 1 can be manufactured.

At this time, as shown in FIG. 5, the threaded portion of the guide portion 3a becomes thicker and becomes the same as the outer diameter of the shaft portion 1.

Note that for rolling, a flat die or the like may be used in addition to the round die as in the above embodiment.

Furthermore, the present invention can be widely applied to the production of screws with grooves such as key grooves, in addition to bolts with cams for adjusting toe-in, camber, etc. of front suspensions used in automobiles.

(Effects of the Invention) The present invention has the above-described configuration and operation, and since the groove is formed in the pre-rolling step, cutting and deburring after rolling can be omitted, which reduces the processing time. In addition, there is no problem of damage to the cutter, and in addition, there is no equipment cost, processing costs can be significantly reduced, and high-precision screws can be provided, reducing the number of defects. It can be suppressed.

[Brief explanation of the drawing]

1(a) to 1(e) show an embodiment in which the present invention is applied to a bolt with a cam for adjusting toe-in, camber, etc. of a front suspension used in an automobile. ) is a front view, the same figure <b> is a side view seen from the head side, the same figure tc> is a side view seen from the screw part side, the same figure (
d) is a front view of the cam plate fastened to the threaded part, ζe)
is a sectional view of the same side, and FIGS. 2 to 5 show an embodiment of the manufacturing method of the present invention, and FIG. 2(a) is a partial front view of a processed material processed by the heading method. , the same figure (b
) is a cross-sectional view taken along line bb in Fig. 2(a), and Fig. 2(C)
is an enlarged view of FIG. 2(b), FIG. Fig. 5 is an enlarged plan view of the threaded portion. Explanation of symbols 1... Shaft portion 3... Threaded portion 3a...
Guide portion 3b...Groove portion 3c for preventing rotation...
Relief groove 6... Die of rolling device 7... Processing material 8... Thread forming part brush 4 Figure

Claims (2)

[Claims] (1) A threaded portion is provided on the outer periphery of the shaft, and a first thread extending from the tip of the shaft in the axial direction to a midway position of the threaded portion is provided in the threaded portion.
A threaded screw component characterized in that a groove is provided, and a second groove having the same width as the first groove is provided in the threaded portion at a position axially symmetrical to the first groove. (2) A thread forming material having a circular cross section has a first groove extending from one end of the material to an intermediate position of the material in the axial direction;
A second groove having the same width as the first groove is formed at a position axially symmetrical to the groove, and then the first and second grooves of the material are formed on the outer periphery of the material.
A method for manufacturing a threaded screw part with a groove, characterized in that a thread is formed by rolling using a circular cross-section without a groove as a guide.