JPH06154926A - Manufacture of sheet metal part provided with ratchet gear - Google Patents

Abstract

PURPOSE:To manufacture the sheet metal part capable of reducing the weight and cost by obtaining the ratchet gear with high rigidity even using sheet metal raw material having relatively small thickness and accordingly, light in weight at the time of manufacturing the sheet metal part integrally provided with the ratchet gear. CONSTITUTION:A circular recessed part 6 is drawn on the sheet metal raw material 1X, the recessed part 6 is then compressed in the direction where the depth becomes smaller to increase the thickness of an annular peripheral wall 10 than the sheet metal raw material thickness and then, the ratchet gear 7 is formed on the inner peripheral surface of the recessed part 6 to manufacture the sheet metal part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sheet metal part having ratchet teeth, and more particularly to a method for integrally forming the ratchet teeth on the sheet metal part.

[0002]

2. Description of the Related Art In various devices that require a ratchet mechanism, a ratchet gear and a sheet metal part which is a supporting member of the gear are separately manufactured and the ratchet gear is assembled to the sheet metal part. .

[0003]

However, if the sheet metal part and the ratchet gear are separately manufactured and combined with each other, the number of parts and the cost are increased, and the weight reduction of the apparatus is hindered. is there.

Therefore, an object of the present invention is to solve the above-mentioned problems by providing a method of manufacturing a sheet metal part integrally provided with ratchet teeth.

[0005]

[Means for Solving the Problems] That is, claim 1 of the present invention.
The invention described in (hereinafter, referred to as the first invention) is a recess forming step of forming a circular recess on one surface side of a sheet metal material by drawing, and compressing in a direction in which the depth of the recess is reduced. It is characterized by comprising a compression step of increasing the wall thickness of the annular peripheral wall of the recess and a ratchet tooth forming step of processing ratchet teeth on the inner peripheral surface of the recess following the compression step.

Further, in the invention described in claim 2 (hereinafter referred to as the second invention), the compression step increases the wall thickness of the annular peripheral wall of the concave portion, and the inner peripheral surface of the annular peripheral wall and the concave portion of the sheet metal material. It is characterized in that it is a step of reducing the curvature of the corner where the opening side surface intersects.

[0007]

According to the first aspect of the present invention, after the recess is compressed in the compression step to increase the wall thickness of the annular peripheral wall of the recess,
By processing the inner peripheral surface of the annular peripheral wall into a ratchet tooth shape, a sheet metal part integrally provided with ratchet teeth can be obtained. Then, in that case, since the ratchet teeth are formed in the portion where the wall thickness is increased as described above, even if a sheet metal having a relatively thin plate thickness and therefore a light weight is used, a high rigidity part of the ratchet tooth part is formed. can get.

Further, according to the second aspect of the invention, since the curvature of the corner portion between the inner peripheral surface of the annular peripheral wall and the sheet metal surface is reduced by the compression process, ratchet teeth can be formed up to this corner portion. A ratchet tooth having a large tooth width can be obtained even if a thin sheet metal having a relatively large thickness is used.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a sheet metal part 1 manufactured by the method of the present invention. The sheet metal part 1 has a downward U-shape as a whole, and a ratchet shaft (not shown) is passed through the left and right blades 2, 3. Shaft holes 4 and 5 for opening are provided, and one shaft hole 4 is provided in a recess 6 which is recessed inward in the blade piece 2, and the shaft hole 4 is formed on the inner peripheral surface of the recess 6. Ratchet teeth 7 are formed concentrically.

A method of manufacturing the sheet metal part 1 will be described.
The sheet metal material 1X cut into a predetermined shape is subjected to a plurality of press working steps shown in FIGS.
The part is squeezed to form a concave part in order, and the shape of this concave part is
→ 6B → 6C are sequentially shaped to make a circular shape with the outer peripheral surface approaching the surface of the sheet metal material at a right angle. That is, in the pressing step of FIG. 3, first, the concave portion 6A that is largely curved is bulged by the molds 8A and 9A, and in the pressing step of FIG. 4, the concave portion 6B is moved in the direction of eliminating the curvature by the molds 8B and 9B. Molded and mold 8 in the pressing process of FIG.
With C and 9C, the annular peripheral wall 10 forms a recess 6C that is substantially perpendicular to the surface of the sheet metal material.

Next, the sheet metal blank 1X is subjected to a plurality of press working steps shown in FIGS. 6 to 8 to compress the recess while maintaining the outer diameter of the recess at a constant dimension D1. That is, in the pressing step of FIG. 6, the outer diameter diameter dimension of the recess 6D is adjusted to a predetermined dimension D1 by using the dies 8D and 9D, and the annular peripheral wall 10 of the recess 6D has a recess depth H1 (see FIG. 9).
And compress it so that it becomes shallow. Further, in the pressing step shown in FIG. 7, the annular peripheral wall 10 is further compressed while using the molds 8E and 9E to maintain the outer diameter diameter dimension at D1.
The depth of the recess 6E is reduced from H1 to H2 (see FIG. 10). As is clear from the comparison between FIGS. 9 and 10, the sheet metal material is extruded inward by the amount of compression of the annular peripheral wall 10 and the wall thickness of the annular peripheral wall 10 is increased from M1 to M2. Further, in the press working process of FIGS. 6 and 7, the curvature of the corner between the annular peripheral wall 10 and the surface 11 on the opening side of the recesses 6D, 6E of the sheet metal blank 1X indicated by the arrow Z in these figures becomes small. Molds 8D, 8E, 9D,
The 9E shape is selected. Then, a final compression process is applied by the dies 8F and 9F in the pressing process of FIG. 8, and the depth of the recess 6 becomes H2 as shown in FIG.
From H to H3 and the thickness of the annular peripheral wall 10 is M
It is increased from 2 to M3, and the curvature of the corner shown by the arrow Z is formed small near the right angle. Similarly, the inner corner of the recess shown by arrow Y is also processed so that the curvature becomes small.

In this way, the tool 1 for ratchet tooth forming is formed on the recess 6 in the next step from the opening side of the recess 6.
12 is formed to form ratchet teeth 7 on the inner peripheral surface of the annular peripheral wall 10 as shown in FIG. 12, after which shaft holes 4 and 5 as shown in FIGS. 1 and 2 are opened, and the sheet metal material 1X is also formed.
The sheet metal part 1 is manufactured by bending. The order of drilling and bending the shaft holes 4 and 5 is not particularly limited.

According to such a manufacturing method, the thickness of the annular peripheral wall 10 on which the ratchet teeth 7 are formed is increased from the original thickness of the sheet metal blank 1X by the compression processing steps shown in FIGS. Therefore, even if the sheet metal material 1A having a relatively thin plate thickness and a light weight is used, the sheet metal part 1 integrally provided with the ratchet teeth 7 having high rigidity can be obtained, and the number of parts can be reduced, which also contributes to the ratchet mechanism. There are merits such as weight reduction, cost reduction, and size reduction.

Further, since the curvature of the annular peripheral wall 10 of the recess 6 and the corner of the sheet metal material 1X on the opening side of the recess is made small, the ratchet teeth 7 can be formed up to this corner, and as described above, the thickness is relatively thin. Even if the sheet metal material 1X is used, a ratchet tooth 7 having a large tooth width W (see FIG. 12) can be obtained,
The ratchet mechanism operates reliably.

As an example of the sheet metal part 1 having the ratchet teeth 7 as described above, a sheet metal part used in a seat belt mechanism of an automobile can be considered.

[0017]

As is apparent from the above description, according to the present invention, after the recess is compressed in the compression step to increase the wall thickness of the annular peripheral wall of the recess, the ratchet is formed on the inner peripheral surface of the annular peripheral wall. By forming the teeth, a sheet metal part integrally provided with ratchet teeth can be obtained. In that case, since the ratchet teeth are formed in the portion where the wall thickness is increased as described above, even if a sheet metal material having a relatively thin plate thickness and therefore a light weight is used, a component having a high ratchet tooth part rigidity. Therefore, the weight of the ratchet mechanism is reduced,
Cost reduction and downsizing can be achieved.

Furthermore, since the curvature of the corner portion between the inner peripheral surface of the annular peripheral wall and the one surface of the sheet metal is reduced by the compression process,
Ratchet teeth can be formed up to this corner portion, and even if a thin sheet metal having a relatively thick plate is used as described above, a ratchet tooth having a large tooth width can be obtained, and the operation of the ratchet mechanism is ensured.

[Brief description of drawings]

FIG. 1 is a front view of a sheet metal part obtained by the method of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view showing a first-stage drawing process.

FIG. 4 is a sectional view showing a second drawing process.

FIG. 5 is a cross-sectional view showing a third drawing process.

FIG. 6 is a sectional view showing a first-stage compression step.

FIG. 7 is a sectional view showing a second-stage compression step.

FIG. 8 is a cross-sectional view showing a third compression step.

FIG. 9 is an enlarged view of a main part of FIG.

FIG. 10 is an enlarged view of a main part of FIG. 7.

11 is an enlarged view of a main part of FIG.

FIG. 12 is an enlarged view after forming ratchet teeth.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet metal part 6 Recessed part 7 Ratchet tooth 8A-8F Mold 9A-9F Mold 10 Annular peripheral wall

Claims (2)

[Claims] 1. A recess forming step of forming a circular recess on one surface side of a sheet metal material by drawing, and increasing the thickness of an annular peripheral wall of the recess by compressing the recess in a direction of decreasing the depth. A method of manufacturing a sheet metal component having ratchet teeth, comprising a compression step and a ratchet tooth forming step of processing ratchet teeth on the inner peripheral surface of the recess following the compression step. 2. The compressing step is a step of increasing the wall thickness of the annular peripheral wall of the recess and reducing the curvature of the corner where the inner peripheral surface of the annular peripheral wall and the surface of the sheet metal material on the opening side of the recess intersect. The method for manufacturing a sheet metal component having ratchet teeth according to claim 1, wherein the method is provided.