JPH0124935B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a back plate of a drum brake, particularly to a back plate of a drum brake in which a reinforcing plate and a back plate main body are integrally joined by drawing, and a method for manufacturing the same. It is something.

[Prior Art] A back plate of a drum brake is fixedly supported on a non-rotating part of a vehicle to close one end of the brake drum, and supports a hydraulic cylinder device, an anchor member, and a pair of brake shoes inside the brake drum. do. The back plate of a drum brake not only closes the inside of the drum brake, but also serves to receive braking torque, so in order to reduce weight, it is preferable to use a plate as thin as possible and to reinforce the parts that receive braking torque. .

In conventional back plates, the back plate main body and the reinforcing plate are molded separately and then joined together, so if the relative positions of the two are shifted when they are joined, assembly with other components and performance will be affected.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, an object of the present invention is to press-form the back plate main body and the reinforcing plate in a state where they are overlapped with each other, and form a depression in the overlapped portion of the two. To provide a back plate of a drum brake which is integrally connected, is free from positional deviation, and has sufficient strength in required parts.

[Means for Solving the Problem] In order to achieve the above object, the configuration of the present invention is such that a back plate main body fixed to a non-rotating part of a vehicle body and closing one end side of a brake drum includes a portion surrounding an axle hole. The reinforcing plates including the portion for fixing the anchor member of the brake shoe are overlapped and connected by an elliptical tapered recess integrally formed in the overlapping portion surrounding the axle hole.

[Function] Since an elliptical tapered recess 18 is formed in the portion of the back plate body 5 and the reinforcing plate 12 surrounding the axle hole 8, relative rotation between the back plate body 5 and the reinforcing plate 12 is prevented even without welding. The reinforcing plate 12 is frictionally bonded to the back plate main body 5 in an overlapping state by the elliptical tapered recess 18, and the back plate is pressed to be lightweight and have sufficient strength in required parts. You can easily get it by just

[Embodiment of the Invention] As shown in FIG. 1, the back plate main body 5 is provided with an axle hole 8 in the center through which the axle passes, and a reinforcing plate 12 is superimposed around this hole to fix it to the suspension system of the vehicle. Four bolt holes 7 are provided for the purpose. Axle hole 8
A substantially elliptical flat surface 5a surrounding the (Fig. 2)
The outer circumferential side of the surface is raised above the surface 5a from the elliptical tapered recess 18 to form a flat surface 5b, and the outer circumferential side of the surface 5b is lowered from the stepped portion 14 to form an annular surface. 5c is formed, and the peripheral edge 4 is bent into a cylindrical shape.

In the upper part of the back plate main body 5, a hole 2 for fitting a hydraulic cylinder device (not shown) into the surface 5b.
are provided, and a mounting bolt hole 3 is provided adjacent to the hole 2. Holes 6 are provided in the left and right portions of the back plate body 5 for attaching struts for guiding and supporting the webs of a pair of brake shoes. An anchor member 16 is coupled to the lower portion of the back plate main body 5 by a rivet 9.

As shown in FIG. 2, the reinforcing plate 12 is connected to the back plate body 5.
are overlapped and drawn together.

Peripheral portion 12a surrounding the axle hole 8 of the reinforcing plate 12
is formed together with the back plate main body 5 and is engaged with the oval tapered recess 18. In order to support the anchor member 16, the lower part of the reinforcing plate 12 is condensed with the back plate main body 5, and is raised higher than the surface 5b from the elliptical tapered recess 18, so that the flat surface 1
2c and 5d are configured. The lower edge of the reinforcing plate 12 is bent flat from the stepped portion 12d and overlapped with the surface 5b of the back plate main body.

In this way, the reinforcing plate 12 has an oval tapered recess 18 between the flat surface 12e surrounding the axle hole 8 and the raised surface 12c that is one step higher than the surface 12e, together with the back plate main body 5. It is drawn and formed into
tightly coupled to each other. At the same time, a surface 1 for supporting the anchor member 16 at the surface 5d of the back plate main body 5
2c is raised and is also tightly coupled to the back plate main body 5. Anchor member 1 made of a thick plate on surface 12c
6 and the retaining plate 10 are overlapped and fixed with rivets 9.

As shown in FIGS. 1 and 3, a pair of depressions 12b are drawn on both sides of the reinforcing plate 12 together with the back plate main body 5, as shown surrounded by chain lines.
2b, the back plate main body 5 and the reinforcing plate 12 are closely engaged.

When actually manufacturing the above-mentioned back plate, the back plate main body 5 is punched out in a circular shape, the reinforcing plate 12 is punched out in an almost shell shape, and these are superimposed in a fixed position using a predetermined jig, and then a press machine is used. After drawing the elliptical tapered recess 18, the axle hole 8 and the like are drilled. That is, an elliptical tapered recess 18 is formed in the overlapping surfaces 5a and 12e of the back plate main body 5 and the reinforcing plate 12 by the drawing process, and the anchor member 1
A raised surface 12c is formed to support 6, and a depression 12b is further formed. Therefore, there is no misalignment of the axle hole 8 or the holes 7, 2, 3, and 6, and the drawing parts of the oval tapered recess 18, the raised surface 12c, and the recess 12b are aligned with the back plate main body 5. Since the reinforcing plate 12 is firmly engaged, there is no fear that the two will separate.

Incidentally, instead of using a suitable jig, the back plate main body 5 and the reinforcing plate 12 may be spot-welded in advance at a portion where no drawing process is involved.

[Effects of the Invention] As described above, the present invention fixes the part surrounding the axle hole and the anchor member of the brake shoe to the back plate main body which is fixed to the non-rotating part of the vehicle body and closes one end side of the brake drum. The reinforcing plates including the two parts are overlapped and connected by an oval tapered recess that is integrally formed in the overlapping part surrounding the axle hole, so it can be reinforced with the main body of the back plate without special welding. A connection with no displacement can be obtained with the plate.

Compared to the conventional method in which the back plate body and reinforcing plate are formed separately and then welded, there is no connection error between the back plate body and the reinforcing plate, and a back plate that is lightweight and has sufficient strength can be obtained. .

The positions of the holes for supporting the anchor member and the hydraulic cylinder device in the back plate, and the holes for attaching the back plate main body to the suspension device are precisely machined.

The rigidity of the back plate is improved by the oval tapered recess surrounding the axle hole in the back plate main body and the reinforcing plate.

[Brief explanation of drawings]

1 is a front view of a back plate of a drum brake according to the present invention, FIG. 2 is a sectional view taken along the line ``-'' in FIG. 1, and FIG. 3 is a sectional view taken along the line ``-'' in FIG. 1. 5: Back plate body, 8: Axle hole, 12: Reinforcement plate, 1
2b: hollow, 12c: surface, 16: anchor member, 1
8: Oval tapered depression.

Claims (1)

[Claims] 1. A reinforcing plate that is fixed to a non-rotating part of the vehicle body and that closes one end of the brake drum, and that includes a part that surrounds the axle hole and a part that fixes the anchor member of the brake shoe. What is claimed is: 1. A back plate of a drum brake, characterized in that these are overlapped and connected by an oval tapered recess integrally formed in an overlapping portion surrounding an axle hole. 2. A process of punching out the back plate main body and the reinforcing plate from a flat plate, a process of overlapping the reinforcing plate at a predetermined position on the back plate main body, and drawing an oval tapered recess in the back plate main body and the reinforcing plate at the same time. a flat first overlapping surface surrounding the axle hole; a flat second overlapping surface raised through an oval tapered recess on the outer circumferential side of the first overlapping surface; a third overlapping surface for supporting an anchor member raised from the surface;
A method for manufacturing a back plate for a drum brake, comprising the steps of forming a recess from a second overlapping surface and punching an axle hole in the first overlapping surface.