Two-stage drum brake chamber

 

The invention relates to mechanical engineering and can be used in the chamber brakes in the automotive industry. Chamber brake contains a two-stage brake drum, brake pads, made of rubber and reinforced around the perimeter steel frame brake chamber, attached to the brake shield, and a pneumatic actuator. On either side of the brake chamber installed in the annular gap between the rim of the brake drum, her body molded U-shaped shelves with branches, to which is attached a friction lining, and from the side of the free edge of the rim of the drum continuation of the branches are the legs attached to the brake shield. The ratio of the coefficient of mutual overlap the upper pairs of friction of the friction nodes and the lower pairs of friction of the friction nodes is equal to the ratio of the radii at which they interact. The technical result is to achieve a uniform distribution of unit loads on interacting friction nodes. 2 Il.

The invention relates to mechanical engineering and can be used in the chamber brakes in a car the material non-rotating brake shield and the friction pad. The compressed air in the chamber is carried out by special pipeline (1, similar, Alexandrov, M. P., Lysakov A. G. Fedoseev, C. N. and other Braking device. - M.: Mashinostroenie, 1985, Fig. 2.54, in; S. 105). This brake implements insufficient braking torque, which affects its effectiveness.

Known drum-type brake in which the elastic elements are in the form located under each friction lining of the chambers filled with liquid under different in each cell pressure, and located transversely of the cylinders, each of which is connected with two adjacent chambers, the friction lining is made with longitudinal protrusions on the sides (2, prototype, and.with. The USSR 1673770 A1, MKI5F 16 D 65/08 (1991)). The brake has the significant disadvantage that it is difficult by design.

In comparison with analogue and prototype of the proposed technical solution has the following distinctive features:

- achieved an increase in braking torques;

- provides a uniform distribution of unit loads on interacting friction nodes that promotes uniform wear;

- high stability due to the lack of nim placement of the friction lining on it, that simplified the design of the brakes;

- most compact brakes.

The present invention is to achieve a uniform distribution of unit loads on interacting pairs of friction of the friction nodes brakes when implementing them large braking torques.

To solve the problem in the known two-stage drum brake chamber containing a two-stage brake drum, special brake pads, brake chambers, made of rubber and reinforced around the perimeter steel frame attached to the brake shield, and a pneumatic actuator according to the invention, on either side of the brake chamber installed in the annular gap between the rim of the brake drum, her body molded U-shaped shelves with branches, which carries friction linings, and from the side of the free edge of the rim of the drum continuation of the branches are the legs attached to the brake shield, while the ratio of overlapping factors of the upper pairs of friction of the friction nodes and the lower pairs of friction of the friction nodes is equal to the ratio of the radii at which they interact.

In Fig.1 shows a longitudinal section of a General view of the second drum brake chamber contains the brake drum 1, with the top 2 and bottom 3 of the friction surface. In the annular gap between the friction surfaces of the brake drum 1 is brake chamber 4, made of rubber, which by its perimeter is reinforced with a steel frame 5.

In the brake chamber in the upper and lower parts also molded plate 6 complex configuration having a U-shaped strip 7 with branches in which holes 8. Similar holes, symmetric specified, performed and in the friction lining 9. The latter are attached to the branches of the plates 6 by means of rivets 10. In addition to the strips 7 with branches plates 6 arranged parallel to the friction surfaces 2 and 3, from the side of the free edge of the rim 11 of the brake drum 1 branch strips 7 have the legs 12. The latter are perpendicular to the friction surface 2 and 3 and in contact with the brake shield 13. The legs 12 holes 14. Similar holes are made in the brake shield 13. Fasten the legs 12 to the brake shield 13 with special bolt 15, which is on the outside of the shield 13 is worn spring washer 16 and is screwed core 17 and locking nuts 18. From the end face of the brake chamber 4 led through the opening 19 in the brake shield 13 of the pipe 20, which is rebandage chamber brake is the ratio of overlapping factors of the upper pairs of friction of the friction nodes (the ratio of the areas of interaction in statics) to the lower pairs of friction of the friction nodes is equal to the ratio of the radii at which they interact.

Two-stage drum brake chamber works as follows.

The first braking mode is possible if the gap between the upper and lower pairs of friction of the friction units are identical. When the supply of compressed air through the pipe 20 into the volume of the brake chamber 4 is its expansion in the radial direction, which leads to the interaction of the working surface of the friction lining 9 with the top 2 and bottom 3 of the friction surfaces of the brake drum 1, and consequently, to its stop.

The second braking mode is possible if the gap between the upper pairs of friction of the friction nodes is smaller than the gap between the lower pairs of friction of the friction nodes. In this case, the first to begin to work the upper pair of friction friction units, braking the brake drum 1. By increasing the pressure of compressed air supplied through a pipe 20 into the volume of the brake chamber 4 increases its radial expansion, which leads to work is change the two-stage drum brake chamber provides a uniform distribution of unit loads on interacting friction nodes, what contributes to their uniform wear when large braking torques developed by the brake of this type.

Claims

Two-stage drum brake chamber contains a two-stage brake drum, brake pads, made of rubber and reinforced around the perimeter steel frame brake chamber, attached to the brake shield, and a pneumatic actuator, characterized in that on both sides of the brake chamber installed in the annular gap between the rim of the brake drum, her body molded U-shaped shelves with branches, which carries friction linings, and from the side of the free edge of the rim of the drum continuation of the branches are the legs attached to the brake shield, while the ratio of overlapping factors of the upper pairs of friction of the friction nodes and the lower pairs of friction of the friction nodes is equal to the ratio of the radii at which they interact.



 

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