JPS6118259Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drum brake actuation device connected to a control cable.

One end of the outer casing of the control cable is fixed to the back plate for positioning, one end of the inner cable is fixed to the free end of the brake lever, and the other end of the control cable is fixed to the back plate. The inner cable is connected to an operating device such as a handbrake lever through appropriate wiring. When the handbrake lever is operated as necessary, the opposing brake shoes mounted on the back plate are opened toward the brake drum via the brake lever or the like by remote control.

Below is an example of a conventional drum brake device.
This will be explained in detail with reference to FIG. Brake shoes 1 and 2 are formed by welding rims 1a and 2a and webs 1b and 2b, respectively, into a T-shaped cross section, and have linings 1c and 2c attached to their outer peripheries. Both upper and lower adjacent ends of the brake shoes 1 and 2 are in contact with a piston of a cylinder 4 fixed to a back plate 3 and an anchor 5. One end of a brake lever 7 is pivotally supported at the upper end of one brake shoe 2 by means of a pin 6. One end of a strut 8 having a function of adjusting the gap between the brake shoes 1 and 2 and a brake drum (not shown) is engaged with the middle part of the brake lever 7, and the other end of the strut 8 is engaged with the other end of the strut 8. It is engaged with show 1. The brake lever 7 is disposed approximately parallel to the web 2b of the brake shoe 2, and has a bent portion bent at an approximately right angle toward the inner side of the free end portion of the other end, that is, the side that engages the strut 8. It has a portion 7a. 9
a and 9b are shoe return springs that pull the brake shoes 1 and 2 inward when the brakes are not activated, and 10a and 10b are hold mechanisms that hold the brake shoes 1 and 2 by lightly pressing them against the back plate 3. be. Reference numeral 11 denotes a pipe which is integrally and firmly fixed to the slope below the back plate 3 and on the side of the brake shoe 1 by caulking, welding, or the like. Reference numeral 12 denotes a control cable, and a casing cap 12b is fixed to one end of the outer casing 12a, and a casing cap 12b is fixed to the pipe 11 with a snap pin 13 or the like. Inside the outer casing 12a is a slidable inner cable 1.
2c is inserted, and one end thereof has a cable end 12 that is hooked to the bent portion 7a of the brake lever 7.
d is fixed. As shown in detail in FIG. 3, a through hole 7b is drilled in a surface parallel to the web 2b of the free end of the brake lever 7 to insert the cable end 12d, and from one end of the through hole 7b, the bent portion 7a is inserted into a suitable position. Continuously connect the inner cable 12c to the position where
A straight slit 7c is provided with a width that allows the cable end 12d to be inserted through the cable end 12d.
12e is a cable spring that is wrapped around the inner cable 12c and is compressed and inserted between the bent portion 7a of the brake lever 7 and the casing cap 12b, and is used to improve the wear resistance of the inner cable 12c and prevent breakage. The purpose is to actively return the brake lever 7. The other end of the control cable 12 is appropriately routed to the vehicle body, etc., and the other end of the inner cable 12c is directly or indirectly connected to an operating device such as a handbrake lever. However, conventionally, in the above structure, when the handbrake is in a non-operating state, the through hole 7b provided at the free end of the brake lever 7 is located on the line of action A, that is, the slit 7c.
It was formed on the extension of the center line of Therefore, before the control cable 12 is routed to the vehicle body, the cable spring 12e bends away from the back plate 3 due to its own elastic force as shown by the dashed line in FIG. 2, and the cable end 12d Problems such as separation from the through hole 7b and half-latching occurred occurred. Also, even after the control cable 12 is routed to the vehicle body,
If the sliding resistance between the brake shoes 1 and 2 and the back plate 3, the rotational resistance between the brake shoe 2 and the pin 6, the cup resistance inside the wheel cylinder 4, etc. become large, the brake lever 7 will move when the parking brake is released. Inner cable 12
c may return. In this case as well, the inner cable 12c bends due to the slack as shown by the dashed line in FIG. 2, which may cause the above-mentioned problem.

There is also a type in which the slot consisting of the through hole 7b and the slit 7c is inclined with respect to the line of action A, but since the through hole 7b is located on the center line of the straight slit 7c, the inner cable 12c is cable end 1 along slit 7c.
When 2d returns to the position of through hole 7b, the same problem as described above occurs.

This invention was created in view of the above drawbacks.
To provide a drum brake actuating device that can reliably prevent a cable end from being half-engaged or detached even when a parking brake is activated or released.

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

As shown in FIGS. 4A and 4B, in the present invention, the through hole 7b provided in the brake lever 7 is a bent slit 7 formed at the free end of the brake lever 7.
It shall be established at a position away from the extension line of the longitudinal part of c.

That is, the bent slit 7c has its longitudinal portion opened along the line of action A, and the bent portion of the slit 7c is opened in a direction intersecting the line of action A.

Furthermore, a through hole 7b is provided at the end of the bent portion of the slit 7c.
will be established.

It is also possible to form a straight slit with a through hole circumscribing the end thereof.

In short, it is only necessary that the through hole 7b be opened at a position off the extension line of the longitudinal part of the slit 7c.

By opening the through hole 7b in a position away from the extension line of the longitudinal part of the slit 7c, the inner cable 12 is opened as shown in FIG. 4A.
When c returns to the through hole 7b, the inner cable 12
c moves while engaging with the inner edge of the through hole 7b outside the brake.

Therefore, the inner cable 12c becomes slack,
Even when the cable end 12d returns to the position of the through hole 7b, since the center of the through hole 7b and the cable end 12d are always eccentric, the outer edge of the cable end 12d is caused to shift due to the eccentricity of both. Since it comes into contact with the peripheral part of the cable end 12d, it is possible to reliably prevent the cable end 12d from being partially hooked or detached.

As described above, according to the present invention, it is only necessary to change the position of the through hole 7 without changing the conventionally used components, so it can be improved very easily.

[Brief explanation of the drawing]

Figure 1 is a plan view of a conventional drum brake, Figure 2 is a plan view of a conventional drum brake.
The figure is a cross-sectional view of FIG. 1, FIG. 3A is a plan view of the main part of a conventional brake lever, FIG. 3B is a side view of FIG. 3A, and FIG. FIG. 4B is a side view of FIG. 4A. 1, 2... Brake shoe, 7... Brake lever, 7a... Bent part, 7b... Through hole, 7c...
Slit, 12...Control cable, 12
c...Inner cable, 12d...Cable end, 12e...Cable spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A drum brake having a brake lever with a through hole in the free end through which the cable end is inserted, and a slit in the bent part that is continuous with the through hole and allows the cable end to be latched. An actuating device for a drum brake, characterized in that the through hole through which the cable end is inserted is opened at a position off the extension line of the longitudinal part of the slit and continuous with the slit.