CN201143932Y - Automotive Brake Master Cylinder - Google Patents

Abstract

The utility model relates to a brake master cylinder of an automobile, which comprises a cylinder body, a first piston that fits in a gap with the cylinder body, a second piston that fits in a gap with the cylinder body and is linked with the first piston, and a first piston that seals the first piston The main cup, the second piston main cup that seals the second piston, the first and second pistons form a first brake chamber and a second brake chamber in the cylinder, and the first and second pistons A compensation hole and an oil inlet are opened, and the main cup slides relative to the piston. By adjusting the opening and closing of the compensation hole and the oil inlet on the corresponding piston, a brake is formed in the first brake chamber and the second brake chamber. hydraulic. The first and second pistons are of different diameter structures. The different-diameter structure of the piston can prevent the piston from scratching the cup, and make the deformation of the cup gradually transition to a normal state, and control the inner diameter of the deformed cup from changing too quickly, which is more conducive to the generation of high pressure in the brake chamber.

Description

Automotive Brake Master Cylinder

technical field

The utility model belongs to the technical field of automobile brakes, in particular to an automobile brake master cylinder which is convenient for machining and assembly and provides good braking performance.

Background technique

The performance of the automobile braking system directly affects the safety of the automobile. In a car, the brake master cylinder is a core component of the brake system. Its function is to generate high-pressure brake fluid to the brake wheel cylinder with enough pressure to push out the friction block and press it against the brake disc, so as to realize the braking effect of the vehicle. brake. With the development of society, cars, as a means of transportation, are slowly entering every family, and users have higher and higher requirements for the performance of cars, especially for safety, which affects the braking performance of vehicles. Stability puts forward higher requirements.

In the existing plunger-type automobile brake master cylinder, in order to balance the pressure difference between the high-pressure chamber and the low-pressure chamber in time after the piston returns, a circle of compensation holes is generally processed on the travel range of the sealing cup. Braking is frequent, and the cup is often cut to the edge of the compensation hole and is easily scratched, resulting in a short service life of the cup. At present, domestic cars are generally equipped with ABS as standard. When braking on roads with low adhesion coefficient such as rain and snow At this time, the cup reciprocates near the compensation hole, and the high-pressure pulsation can easily damage the cup, resulting in seal failure and serious consequences of brake failure.

Therefore, there is an urgent need for a new automobile brake master cylinder that can solve the above-mentioned problems occurring in the above-mentioned traditional automobile brake master cylinder.

Contents of the invention

The purpose of the utility model is to overcome the defects of the above-mentioned prior art, and provide an automobile brake master cylinder which is convenient for machining and assembly and provides good braking performance.

In order to achieve the above-mentioned purpose, the technical solution of the present invention is: an automobile brake master cylinder, including a cylinder body, an end cover for sealing the cylinder body, a first piston that is in clearance with the cylinder body, a clearance fit with the cylinder body and accompanied by a second A second piston linked by a piston, a first piston main cup that seals the first piston, and a second piston main cup that seals the second piston, the first and second pistons form a first brake chamber in the cylinder and the second brake chamber. The first and second pistons are provided with compensation holes and oil inlets. The main cups of the first and second pistons slide relative to the first and second pistons. By adjusting the corresponding pistons The opening and closing of the upper compensation hole and the oil inlet forms brake hydraulic pressure in the first brake chamber and the second brake chamber. The first and second pistons are of different diameter structures.

Preferably, the different-diameter structure means that each piston includes a thin end with a smaller diameter and a thick end with a larger diameter.

Preferably, the diameter of the thin end is the inner diameter of each piston main cup in a free state.

Preferably, the transition between the thin end and the thick end of each piston is through a sharp chamfer and a slow chamfer.

The utility model adopts the technical solution, and its beneficial technical effect is that: in the vehicle brake master cylinder of the utility model, the first and second pistons are different-diameter structures, that is, each piston includes a smaller-diameter The thin end, the thick end with a larger diameter to achieve sealing and the transitional chamfer, the thin end can prevent the piston from scratching the cup, and the sharp chamfer will be generated too quickly when the cup passes over the piston compensation hole It has a certain degree of sealing and builds up a certain pressure in the corresponding brake chamber. The small chamfering angle makes the deformation of the cup gradually transition to the normal state, and the inner diameter of the deformed cup is controlled to change too fast, which is more conducive to the brake system. Generation of high pressure in the moving chamber.

Description of drawings

Fig. 1 is a structural schematic diagram of the utility model automobile brake master cylinder.

Fig. 2 is a schematic diagram of the piston structure of the brake master cylinder of the utility model.

Detailed ways

Below through specific embodiment and in conjunction with accompanying drawing, the utility model is further described.

Please refer to Fig. 1 to Fig. 2, the utility model relates to a kind of brake master cylinder of automobile, comprises cylinder body 1, the end cover 17 of sealing cylinder body 1, first, second piston guide support (18,6), first Piston 19, the second piston 4 linked with the first piston 19, the first piston main cup 21 and auxiliary cup 20 for sealing the first piston 19, the second piston main cup 5 and auxiliary cup for sealing the second piston 4 Bowl 7.

The end cover 17 is threadedly connected with the cylinder body 1 and sealed with an O-ring 14 and a steel wire retaining ring 15 . The first piston 19 and the second piston 4 form a first brake chamber A and a second brake chamber B in the cylinder body 1 . Compensation holes and oil inlets (not shown) are opened on the first piston 19 and the second piston 4 . The first piston 19 and the second piston 4 are mounted in the first and second piston guide brackets (18, 6) with gaps. The first piston lead support 18 is in clearance fit with the end cover 17, and the second piston lead support 6 is in clearance fit with the cylinder body 1 . The seal between the first piston lead support 18 and the first piston 19 is carried out by the first piston main cup 21 and the first piston auxiliary cup 20, and the connection between the second piston lead support 6 and the second piston 4 is sealed. The space is sealed by the second piston main cup 5 and the second piston auxiliary cup 7.

In this embodiment, the first piston main cup 21 and the second piston main cup 5 slide relative to the first piston 19 and the second piston 4. By adjusting the opening and closing of the compensation hole and the oil inlet on the corresponding piston, the Brake hydraulic pressure is formed in the first brake chamber A and the second brake chamber B.

As shown in FIG. 2 , the first piston 19 and the second piston 4 of the present invention are designed with different diameter structures.

The different-diameter structure means that both the first piston 19 and the second piston 4 include a thin end 34 with a small diameter and a thick end 35 with a large diameter for sealing. The diameter of the thin end 34 is the inner diameter of the primary cups (21, 5) of the first piston 19 and the second piston 4 in a free state. The transition between the thin end 34 and the thick end 35 of the first piston 19 and the second piston 4 is through a sharp chamfer 31 and a slow chamfer 32 in sequence.

When the thin end 34 passes through the main cup (21, 5), there is no interference between the main cup (21, 5) and the first piston 19 and the second piston 4, which can fully avoid the scratch of the cup hurt. The chamfer between the thin end 34 and the thick end 35 is divided into two parts, including a sharp chamfer 31 with a large front chamfer angle and a slow chamfer 32 with a small rear chamfer angle.

Please refer to Fig. 1 at the same time. When not braking, the main cup 21 of the first piston is located at the thin end 34 of the first piston 19, and does not completely block the passage between the compensation hole and the oil inlet on the piston 19. The first piston of the master cylinder The first brake chamber A, the second brake chamber B and the liquid storage pot are directly connected by passages, all of which are low-pressure chambers. When braking, as the master cylinder push rod moves forward, the first piston 19 moves forward, and when the first piston main cup 21 gradually crosses the compensation hole on the first piston 19 and reaches the part of the large chamfer, it will quickly There is a small interference, which has a certain degree of sealing, and cuts off the passage between the first brake chamber A of the master cylinder and the oil inlet, and the pressure of the first brake chamber A gradually rises. At the same time, the first piston 19 pushes the second piston 4 to overcome its return spring force and frictional force to move forward, and the second piston main cup 5 gradually passes over the compensation hole on the second piston 4, so that the second piston of the master cylinder brakes. Chamber B also begins to build hydraulic pressure; as the braking action continues, the main cups (21, 5) of the first and second pistons (21, 5) reach the part where the chamfering angle of the first and second pistons (19, 4) is small, and control the first , The inner diameter of the two-piston main cups (21, 5) changes too fast and produces higher pressure brake fluid to meet the needs of vehicle braking.

Although the preferred embodiment of the present invention has been described in detail above, it should be understood that many variations and modifications of the basic inventive concept that are obvious to those skilled in the art fall within the scope of the appended claims. within the spirit and scope of the invention.

Claims (4)

1. automobile braking master cylinder, comprise cylinder body, the end cap of sealed cylinder block, first piston with the cylinder body free-running fit, with the cylinder body free-running fit and with second piston of first piston interlock, the first piston primary cup of sealing first piston, seal the second piston primary cup of second piston, described first, second piston forms first brake chamber and second brake chamber in cylinder body, described first, offer compensation orifice and oil inlet on second piston, described first, the second piston primary cup is with respect to first, second piston slides, thereby the folding of compensation orifice and oil inlet forms brake fluid pressure on the corresponding piston in first brake chamber and second brake chamber by adjusting, and it is characterized in that: described first, second piston is the reducing structure.

2. automobile braking master cylinder according to claim 1 is characterized in that: described reducing structure is meant thin end and the bigger butt end of diameter that each piston comprises that diameter is less.

3. automobile braking master cylinder according to claim 2 is characterized in that: the diameter of described thin end is the internal diameter under each piston primary cup free state.

4. according to claim 2 or 3 described automobile braking master cylinders, it is characterized in that: between the thin end of each piston and the butt end by the gentle chamfering transition of anxious chamfering.

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