JP2568876Y2 - Drum brake cable guide - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a cable for guiding a cable for pulling a parking lever in a drum brake through a hole in a backing plate to the outside of the brake in order to drive a parking brake mechanism in a drum brake. About the guide.

[0002]

2. Description of the Related Art One example of a drum brake used for braking an automobile is shown in FIGS. 8 and 9, which will be described below. In this description, up, down, left and right refer to FIG.

A wheel cylinder 2 and an anchor 7 are fixed to an inner surface of the backing plate 1 fixed to the suspension device (the surface on which the brake mechanism is provided is defined as an inner surface).
Left and right brake shoes 3a, 3b supported at both ends by piston rods 2a, 2b of a wheel cylinder and an anchor 7 are provided movably along the backing plate 1. A drum (not shown) that rotates with the wheels is provided over both brake shoes.

An upper end of a parking lever 5 is pivotally connected to an upper portion of the right brake shoe 3b by a pivot 4. A strut 6 extends between each upper portion of the parking lever 5 and the left brake shoe 3a. Have been. 9 is a return spring that pulls the brake shoes 3a and 3b together.

A cable (not shown) is attached to the lower end of the parking lever 5 for pulling the parking lever to the left during parking to apply a parking brake. The cable is guided by a cable guide 10 and a base 11 fixed on both sides of the backing plate 1 with the backing plate 1 therebetween, and is introduced into the inner surface of the backing plate.

In order to perform braking by the drum brake, pressure oil is supplied to the wheel cylinder 2 and the piston rod 2a,
2b is pushed out, and the brake shoes 3a and 3b are spread and pressed against the inner peripheral surface of the drum. When the pressure oil is removed from the wheel cylinder 2, the brake shoes 3a and 3b are pulled by the return spring 9 to separate from the drum, and the braking is released.

To apply the parking brake, the cable is pulled and the parking lever 5 is rotated clockwise about the pivot 4.

As a result, the parking lever 5 first makes a small rotation with the strut 6 as a fulcrum, moves the pivot 4 outward, presses the lining 8 of the right brake shoe 3b against the inner peripheral surface of the drum, and then moves immovably. The strut 6 is pushed leftward with the pivot 4 as a fulcrum, and the left brake shoe 3a
To press the lining 8 against the inner peripheral surface of the drum, whereby the drum cannot rotate and the parking brake is applied.

If the cable is loosened, the brake shoe will not be extended by the parking lever 5, so that
The parking brake is released.

The cable guide 10 is composed of a guide portion 10a having a U-shaped cross section with both sides folded up and a base portion 10b having a flat plate shape. The base portion 10b is provided with a hole 10c through which a cable passes.
It is attached to the backing plate 1 by point welding at a point a at the tip of the guide portion 10a and a point b at the base 10b.

The backing plate 1 is provided with a hole 1a corresponding to the cable guide hole 10c, and
The cable passage holes are aligned with the holes 1a and 10c and attached.

In order to attach the base 11 to the backing plate 1, a bolt 12 whose bottom surface is projection-welded to the base 10b is projected through the hole of the backing plate to the outer surface of the backing plate, and is inserted into the hole of the flange 11a of the base 11. Then, the nut 13 is tightened.

[0013]

When such a bolt 12 for mounting a base is projection-welded to the base 10b of the cable guide, molten metal is scattered or thermally distorted, so that the molten metal is prevented from flowing out. Or means to stabilize the mounting position of the bolt is required, which not only complicates the welding equipment, but also limits the material of the bolt,
It was inevitable that the cost would increase as a whole.

[0014]

The cable guide of the drum brake according to the present invention does not use welding means, but is a combination of a bolt for mounting a base and a base of the cable guide by caulking means. was formed by burring in a position for mounting bolts of the base, in which is inserted a bolt into a hole with a standing wall surrounding, comprising tightly bound the bolts and the base by caulking to crush the vertical wall is pressurized in the axial direction is there.

[0015]

[Action] by inserting the bolt into a hole of the vertical wall around and burring formation, and pressure Tsubusuru pressurizes the vertical wall in the axial direction, the meat is strongly sandwich the bolt flow toward the periphery of the bolt.

If a small projection is formed on the lower surface of the head of the bolt so as to engage with a hole formed in the base, the nut can be prevented from spinning when the nut is tightened for mounting the base.

When the bolt is attached to the base of the cable guide in this way, spatter does not occur as in welding and there is no thermal distortion. Therefore, the bolt is attached to a predetermined position of the base in a predetermined posture, and the bolt is attached. Can be used to attach the base to the backing plate.

[0018]

1 to 7 show a manufacturing state and a structure of a cable guide to which bolts are connected according to the present invention, and FIG. 1 is a plan view of a cable guide in which bolt mounting holes are formed by burring to have an upright wall. , FIG. 2 is a cross-sectional view taken along the line BB of FIG. 1, FIG. 3 is a cross-sectional view showing a state in which a bolt is inserted into the hole, FIG. FIG. 6 is a sectional view showing a state in which a base is attached.
FIG. 7 is a bottom view of the head of the bolt on which the small protrusion for preventing rotation is formed, and FIG. 7 is a cross-sectional view showing a state where the bolt is attached to the base of the cable guide.

In order to manufacture the cable guide of the present invention, first, as shown in FIGS. 1 and 2, holes 15 having a vertical wall 15a around the periphery thereof are formed by burring at positions where bolts are to be mounted.

Next, as shown in FIG. 3, the bolt 12 is inserted into the hole 15 and protrudes from the back surface of the base 10b of the cable guide.
While supporting the end of the upright wall 15 a with the base metal 16, the bolt is subjected to high pressure fringing with the pressing tool 17 from above.

As a result, the standing wall 15a is crushed, and the flesh flows into the hole 15, and as shown in FIG.
And the bolt 12 is strongly clamped.

In the cable guide in which the bolts 12 are firmly connected as described above, the bolts 12 are inserted into the bolt holes formed in the backing plate 1 as in the prior art, the base 11 is fitted to the bolts 12, and the nuts 13 are tightened. Then, the base 11 is fixed to the backing plate 1 as shown in FIG.

The base 10b of the cable guide is
2 is spot-welded to the backing plate 1 as before.

When the nut 13 is tightened to fix the base 11 to the backing plate 1, if the bolt clamping action by the caulked portion is not sufficient, there is a possibility that slippage may occur and the nut may not be securely tightened. . Therefore, one or a plurality of small projections 18 are formed on the lower surface of the head of the nut 13 as shown in FIG. 6, and these are engaged with holes 19 or recesses formed in the base of the cable guide as shown in FIG. If the vertical wall is crushed or crimped, the bolt can be prevented from running idle when the nut 13 is tightened.

Alternatively, a hexagonal or quadrangular square portion may be formed in the neck portion of the bolt, and the crushed wall may surround the wall to prevent the bolt from running idle.

[0026]

[Effects of the Invention] (1) Conventional bolts are not attached to the cable guides without using welding means, so that there is no scattering of molten metal or thermal deformation, and there is no limitation on material selection of bolts. In this case, the disadvantage in the case (1) is eliminated, and the cost of the cable guide connected with the bolt can be reduced.

(2) Since the flesh raised around the bolt hole 15 as the vertical wall 15a is crushed by burring, the gap between the bolt 12 and the hole 15 is filled and the guide 1
The connection between 0 and bolt 12 can be made sufficiently strong.

(3) If a small projection is formed on the lower surface of the head of the bolt 12 and is engaged with the hole 19 or the concave portion at the base of the cable guide, it is possible to reliably prevent the bolt from idling when the nut is tightened.

[Brief description of the drawings]

FIG. 1 is a plan view of a cable guide in which a bolt hole for attaching a base is formed by burring.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a cross-sectional view of a base of a cable guide before a bolt is inserted into a bolt hole and a standing wall is crushed.

FIG. 4 is a cross-sectional view of the base of the cable guide after crushing the standing wall.

FIG. 5 is a sectional view showing a state in which the base is fastened to the backing plate by a nut.

FIG. 6 is a bottom view of the bolt formed with small projections for preventing the bolt from spinning.

FIG. 7 is a sectional view showing a state in which the small projection is engaged with the hole of the cable guide and the bolt and the backing plate are caulked.

FIG. 8 is a plan view illustrating the inside of a drum brake.

FIG. 9 is a sectional view taken along line AA of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Backing plate 1a Hole 2 Wheel cylinder 2a Piston rod 2b Piston rod 3a Brake shoe 3b Brake shoe 4 Axis 5 Parking lever 6 Strut 7 Anchor 8 Lining 9 Return spring 10 Cable guide 10a Guide 10b Base 10c Hole 11 Base 12 Bolt 13 Nut 15 hole 15a standing wall 16 base metal 17 pusher 18 small projection 19 hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunikatsu Kuroda 6-3-12, Honcho Nishi, Yono-shi, Saitama Japan Co., Ltd. Ohashi Technica Saitama Branch (72) Inventor Takeo Komatsu 1823 Akiganuma, Yoga, Suwa-shi, Nagano Shares In the company Kanesan Works (56) References Japanese Utility Model 63-129732 (JP, U) Japanese Utility Model 63-129731 (JP, U)

Claims (2)

(57) [Scope of request for utility model registration] When a parking brake is applied, one of a pair of brake shoes (3a) and (3b) of a drum brake is connected to the other end of a parking lever (5) pivotally connected at one end by a pivot (4). And the parking lever (5)
And a cable guide of a drum brake for guiding a cable for rotating the parking lever (5) about the pivot (4) by pulling the other end of the drum brake, and the cable guide is provided on a base wall (10b) of an upright wall ( A burring hole (15) having a burring hole (15a) and a crimping process for crushing the standing wall (15a) in the axial direction with the shaft portion of the cap mounting bolt (12) inserted through the burring hole (15). As a result, the bolt (1) is formed by the flesh of the standing wall (15a) flowing toward the base mounting bolt (12).
2) A cable guide for the drum brake that clamps the shaft section. 2. The base mounting bolt (12) has a small projection (18) on the lower surface of the head, and the base mounting bolt (12) is provided with a burring hole (15) in the cable guide (10).
The cable guide according to claim 1, wherein the base (10b) has a hole (19) or a recess for engaging with the small projection (18) when inserted into the base.