Self-adjusting type crank drum type brake

Abstract

The invention relates to a self-adjusting type crank drum type brake which comprises a braking bottom plate. Two braking shoes in floating connection with the braking bottom plate are symmetrically arranged on the side face of the braking bottom plate. A crank cylinder body is arranged at the upper end of the braking bottom plate. A crank cam is installed in the crank cylinder body. Two side cylinder bodies extend from the exterior of the crank cylinder body. A piston is installed in each side cylinder body. An adjusting screw rod, a ratchet wheel and a plate are installed on the end portion of each side cylinder body. One end of each adjusting screw rod extends into the corresponding piston, and the other end of each adjusting screw rod directly faces the braking shoes. An adjusting and pulling plate is installed at the front end of the crank cylinder body, one end of the adjusting and pulling plate is clamped with the plates, and the other end of the adjusting and pulling plate makestooth contact with the ratchet wheels. The two braking shoes are mutually connected through a return plate spring. A pulling spring is further installed. According to the brake, an automatic gap adjusting device is arranged in the brake, the two braking shoes are adjusted independently, and the braking stability is improved. After braking, resetting is achieved through the return plate spring, due to the design of the return plate spring, enough space is reserved for assembling the brake, and the assembling efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of vehicle brakes, in particular to a self-adjusting crank drum brake. Background technique [0002] Domestic pneumatic drum brakes mainly adopt "S" type camshaft structure. GB7258-2017 requires that all brakes must be equipped with an automatic adjustment device for brake clearance starting from January 2018. The existing "S" type camshaft structure matches the automatic adjustment. The arm can meet this requirement of the regulations and realize the automatic adjustment of the clearance. After the camshaft is equipped with an automatic adjustment arm, the clearance adjustment mechanism is externally placed on the shaft end of the brake camshaft to realize synchronous adjustment of the braking clearance of the collar and the follower shoe, but there is a risk of over-adjustment of the brake clearance; With the continuous adjustment and compensation of the gap, the "S" shape of the camshaft is continuously ...

AI Technical Summary

Problems solved by technology

After the camshaft is equipped with an automatic adjustment arm, the clearance adjustment mechanism is externally placed on the shaft end of the brake camshaft to realize synchronous adjustment of the braking clearance of the collar and the follower shoe, but there is a risk of over-adjustment of the brake clearance; With the continuous adjustment and compensation of the gap, the "S" shape of the camshaft is constantly opened, and when it is close to the limit position, there is a situation that the camshaft cannot return due to overturning

[0003] In the prior art, the brake shoe of the drum brake generally adopts a structure that rotates around the pin shaft. During the brake wear process, the frictional contact area between the brake shoe that rotates around the fixed shaft and the hub cannot be guaranteed to be uniform, which affects the The braking performance of the vehicle; moreover, the installation position of the return spring used for the brake shoe reset in the prior art also limits the space of the brake when the axle housing is assembled, so that the space for the brake to install the bridge is insufficient, and the operation is troublesome and laborious. low efficiency

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