Piston pump for automobile brake system

Abstract

The invention discloses a plunger pump for an automobile braking system. The plunger pump for the automobile braking system comprises a motor eccentric bearing, a motor shaft, a valve block, a pump oil outlet cavity, a backpressure cavity, an active pressurization oil passing channel, a star-shaped sealing ring, a pump guide sleeve, a pump oil inlet assembly and a pump plunger assembly. The plunger pump is composed of the independent pump oil inlet assembly, the pump plunger assembly, the star-shaped sealing ring, the pump guide sleeve and the valve block, the active pressurization oil passing channel is formed between a low-pressure cavity and the backpressure cavity of the plunger pump, when brake fluid of the low-pressure cavity is compressed by pushback movement of a plunger rod assembly, the brake fluid provides active pressurization for oil absorption of the plunger pump through the active pressurization oil passing channel, and therefore the efficiency of the pump is improved.

Description

technical field [0001] The invention belongs to the field of automobiles, and in particular relates to a plunger pump for an automobile braking system with improved pump efficiency. Background technique [0002] As an anti-lock braking system that improves vehicle stability, ABS greatly improves the safety of driving. The plunger pump is an extremely important part of the system, which is used to decompress the wheels and flow into the ABS accumulator. The fluid is pumped back to the master cylinder. The efficiency of the plunger pump directly affects the drop rate of the brake fluid pressure of the wheel, whether it can effectively prevent the wheel from locking, and also affects the braking effect of the car when braking. [0003] Currently, the structure of the known ABS plunger pump includes an independent oil inlet assembly, an oil outlet assembly, a pump compression spring, a plunger rod assembly, a sealing assembly, and a valve block providing an assembly environment...

AI Technical Summary

Problems solved by technology

Among them, the oil inlet assembly is composed of a center valve hole machined part, a tensile support seat, spring and steel ball, which has the function of a check valve. The center valve hole machined part has a sealing cone surface, and the In the actual mass production process of machining, it is difficult to ensure the consistency of the sealing cone surface, which will reduce the yield of the oil inlet assembly; among them, the oil outlet assembly, the pump compression spring, and the plunger rod assembly cannot be assembled into one piece , the process of installing the above components into the valve block requires separate assembly one by one, increasing the assembly time and difficulty

[0004] In addition, the sealing assembly of the known ABS plunger pump includes a flat gasket and a star-shaped seal ring. When the plunger pump discharges oil, the brake fluid in the pump chamber is under high pressure. At this time, the star-shaped seal ring acts as a high-pressure seal. When the plunger pump sucks oil, the brake fluid in the pump chamber is at low pressure. At this time, the star-shaped sealing ring has a low-pressure sealing effect. Alternate changes in high and low pressure, accelerate the aging and damage of the star seal ring, and the seal of the pump chamber is prone to failure

[0005] In addition, it is known that the smooth reciprocating motion of the ABS plunger pump requires the valve block to provide a sufficiently long plunger rod guide hole, and the surface finish and cylindricity of the guide hole are extremely high. The requirements are extremely high, which increases the difficulty and cost of manufacturing

In addition, it is known that the ABS plunger pump relies on the negative pressure of the pump chamber and the spring force of the accumulator when absorbing oil, and has no main pressurization function, and the oil absorption efficiency is not high; The pump cavity formed between the oil port components is relatively large, and the volume ratio of the oil discharge compression volume in each movement of the plunger pump to the volume of the pump cavity is low, and the oil discharge efficiency is low

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