Powder metallurgy brake shoe with bent welded structure

Abstract

The invention relates to a powder metallurgy brake shoe, in particular to a powder metallurgy brake shoe with a bent welded structure, which comprises a steel backing, a skeleton, a plurality of friction blocks, a brake shoe nose and a stopping block, wherein a brake block is formed on one skeleton by sintering friction blocks; the skeleton is welded onto the steel backing. According to the invention, a plurality of friction blocks are welded onto one whole skeleton at the same time, and then, the whole skeleton is welded onto the steel backing, the powder metallurgy brake shoe has the benefits of large friction area, simple structure, high convenience for processing, short processing periods, low cost, low possibility of looseness and flaking off for brake blocks, and high safety.

Description

technical field [0001] The invention relates to a powder metallurgy brake shoe, in particular to a powder metallurgy brake shoe with a curved welding structure. Background technique [0002] Railway locomotives and vehicles need to be braked during operation, and the braking parts that directly rub against the wheels to stop the vehicle are brake shoes. There are three types of traditionally used brake shoes, namely cast iron brake shoes, synthetic brake shoes and powder metallurgy brake shoes. Cast iron brake shoes have heavy weight, high noise and high wear; synthetic brake shoes have poor heat dissipation performance and pollute the environment; cast iron brake shoes and synthetic brake shoes can only be used on locomotives with a speed of less than 120KM per hour, and their service life is short. With the increase of locomotive speed, higher requirements are put forward for the performance of brake shoes, that is, brake shoes are required not only to have good braking p...

AI Technical Summary

Problems solved by technology

This patented technology uses three small steel backs to pressurize and sinter copper-iron powder metal to form three small friction blocks, and then rivet the three small friction blocks with the skeleton, which has the following defects: 1. Apply pressure on the skeleton to make the friction block When in contact with the wheel tread, the skeleton bears a huge pressure and is easy to break; 2. If the riveting method is used, the friction block and the skeleton are easy to fall off, and the safety is not high. Moreover, the riveting method will take up space and may interfere with other parts. Interference occurs, affecting the performance of the brake shoe

The brake pads of the above three connection methods all have some shortcomings. The first riveting structure is to rivet the brake block on the steel back, and it is necessary to process the riveting holes on the brake block and the steel back. In order to process the riveting holes on the brake block , it is necessary to reduce the area of ​​the friction block on the brake block to expose the skeleton. Due to the reduction of the friction area, it is more difficult to develop the brake material

At the same time, during the braking process, the friction surface of the brake block and the wheel tread generate high frictional temperature, and the rivet is prone to deformation or breakage, which easily leads to loosening and falling off of the brake block, and poor safety. At present, the brake shoe with this riveted structure has been basically eliminated.

The second is the riveting and welding structure. Due to the long processing cycle and high processing cost, brake shoe manufacturers have gradually abandoned this structure.

However, due to the small gap between the middle brake block and the left and right brake blocks, the left and right sides of the brake block cannot be welded, and only the front and rear sides can be welded. At the same time, when the operator welds the middle brake block, the operation is inconvenient due to the small gap , Sometimes there is a false weld, resulting in low welding strength between the upper frame of the middle brake shoe and the steel back, and the brake shoe in the middle of the brake shoe will fall off during the braking process, such as Image 6 As shown, its reliability is low, which affects driving safety

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