Composite brake block

Abstract

A composite brake shoe (1) comprises a back plate (2), a cast iron brake pad (3) and a composite brake pad (4), the cast iron brake pad (3) is cast on the back plate (2), the composite brake pad (4) is fixed on the back plate (5) of the other brake pad (4), and the composite brake pad (4) is mechanically connected to the back plate (2) of the composite brake shoe (1).

Description

Technical Field

[0001] The invention relates to a composite structure brake block for railway vehicles, which is similar in shape to a cast iron brake block but different in structure. Background Art

[0002] Cast iron brake shoes are widely used for braking railway vehicles. During braking, the brake system presses the brake shoes against the vehicle wheels, generating a torque that resists the rotational movement of the wheels. During braking, the vehicle's kinetic energy is converted into heat energy, which the brake shoes and wheels dissipate into the environment.

[0003] Cast iron is a suitable material for brake pads due to its suitable mechanical parameters and low production costs. However, the disadvantages of cast iron brake pads are loud running noise, dust pollution to vehicles and the environment, and frequent maintenance due to severe wear of the brake pads.

[0004] Plastic brake pads are often used to eliminate these disadvantages of cast iron brake pads. In plastic brake pads, the entire brake pad structure is a mixture of resin and filler, which is fixed to a steel backing plate through a pressing and heat treatment process. Compared with cast iron brake pads, plastic brake pads have advantages in terms of noise generation, dust formation and maintenance frequency, but the application of plastic brake pads also has some disadvantages.

[0005] One disadvantage is that braking wears down the contact surface of the wheel, reducing the extremely important friction between the wheel and the rail surface. The safety of braking is affected by the weather, and the braking distance is prolonged in rainy and snowy weather conditions. Another disadvantage is the imbalanced distribution of the thermal load of the component groups involved in braking (i.e., wheels and brake pads), because the thermal conductivity of plastics is negligible, resulting in most of the heat load converted from kinetic energy being concentrated on the wheels. An undesirable consequence of this situation is that, depending on the environment and operating conditions, the wheel may overheat, which may lead to mechanical damage to the wheel. Another disadvantage is that the remaining plastic layer and the backing plate that supports it after the plastic brake pads are worn out will generate waste, which is problematic to recycle and has high disposal costs as hazardous waste.

[0006] One known solution to eliminate these drawbacks is to use a combination of various types of brake pads of different compositions and arrangements on a single brake shoe, usually a combination of a plastic bonded material and a hard material (usually cast iron).

[0007] RU2309072 patent discloses a composite insert mounted on a metal back plate, wherein a hard insert (cast iron insert) is welded in the middle portion. The polymer material is die-cast on the back plate welded with the cast iron insert and then vulcanized.

[0008] The CN101900176 patent discloses a composite brake block, in which a composite insert is welded to a back plate, and the composite element is cold pressed on the back plate and then heat treated to solidify and fix.

[0009] RU2298499 patent discloses a composite brake block with a cast iron frame structure, the cavity of which is filled with a composite friction insert containing a reinforcing metal wire.

[0010] After reviewing existing solutions and summarizing our experience, we found that the issues of heat loss, recycling and waste management, and simpler and more economical manufacturing required further development, so we set it as a goal to improve these issues. Summary of the invention

[0011] The invention for achieving this object is based on the recognition that the cast iron brake pad of the composite brake shoe is individually fixed to the back plate of the brake shoe, while the composite brake pad is individually mounted on its own back plate, which is then fixed to the back plate of the brake shoe.

[0012] The main concept and preferred embodiments of the invention are described in the claims and the dependent claims, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be described in more detail below with reference to the accompanying drawings, in which:

[0014] Figure 1 shows an exploded perspective view of a composite brake shoe assembly, excluding cast iron and composite brake pads,

[0015] Figure 2 shows a rear view of a composite brake shoe with a back plate,

[0016] Figure 3 A perspective view of a composite brake shoe is shown.

[0017] Description of reference numerals:

[0018] 1--Compound brake block

[0019] 2--Back panel

[0020] 3--Cast iron brake pads

[0021] 4--Composite brake pads

[0022] 5--Back panel

[0023] 6--Piercing

[0024] 7--Bump

[0025] 8--Bump

[0026] 9--Bump

[0027] 10--Key Bridge

[0028] 11--Piercing

[0029] 12--Bump DETAILED DESCRIPTION

[0030] The cast iron brake pad 3 is directly fixed on the back plate 2 of the composite brake block 1. A known advantageous embodiment is to cast the cast iron brake pad 3 on the back plate 2. The protrusions 9 formed on the back plate 2 participate in resisting the lateral force generated by the brake wheel, and the fixed cast iron brake pad 3 enhances the rigidity of the back plate 2.

[0031] A through hole 11 for connecting a key bridge 10 is provided on the back plate 2, and the element positions the brake block on the brake caliper (not shown). Before casting the cast iron brake pad 3, the connecting protrusion 12 of the key bridge 10 is actually inserted into the through hole 11. After casting, the protrusion 12 surrounded by cast iron fixes the key bridge 10 and the cast iron brake pad 3 on the back plate 2.

[0032] For clarity, Figure 2 The cast iron brake pad 3 and the composite brake pad 4 are shown only in dotted lines to indicate the positions of these components.

[0033] There are protrusions protruding from the plane of the back plate on the back plate 5 of the composite brake pad 4; at least one protrusion 8 faces the composite brake pad 4.

[0034] The projection 7 facing the back plate 2 is used to guide a wedge, which is not shown in the figure and is a known essential element for fixing the brake pad in the braking system. The projection 7 is also used to fix the back plate 5 on the back plate 2.

[0035] The composite brake pad 4 is fixed to the back plate 5 , preferably by casting or pressing, depending on the material of the composite brake pad 4 .

[0036] The projections 7 of the back plate 5 are inserted into the matching perforations 6 and fixed there, and the back plate 5 together with the composite brake pad 4 are fixed to the back plate 2. The fixing is preferably achieved mechanically by bending the projections 7 by plastic deformation.

[0037] By bending back or breaking the projections 7 on the worn brake pad, the composite brake pad 4 is separated from the back plate 2 and separated from the part to be recycled as waste.

[0038] In addition to ensuring known advantages such as quieter operation than cast iron brake pads and ensuring the appropriate roughness of the wheel contact surface, the composite brake pad 1 is simpler and cheaper to manufacture due to the smaller size and the simplified geometry of the composite brake pad 4 due to the individual production. Most of the worn brake pads can be recycled, generating less waste, which is an environmental advantage.

Claims

1. A composite brake block (1), comprising a back plate (2), a cast iron brake pad (3) and a composite brake pad (4), wherein the cast iron brake pad (3) is cast on the back plate (2), characterized in that: The composite brake pad (4) is fixed on another back plate (5) of the composite brake pad (1), and the back plate (5) is mechanically connected to the back plate (2) of the composite brake block (1).

2. The brake shoe according to claim 1, characterized in that: The composite brake block (1) comprises a cast iron brake pad (3) which at least covers the middle portion of a back plate (2) of the composite brake block (1), and at least one composite brake pad (4) is arranged adjacent to the cast iron brake pad.

3. Brake shoe according to any one of the preceding claims, characterized in that At least one set of mutually locked mounting brackets is provided on the back plate (2) of the composite brake block (1) and the back plate (5) of the composite brake pad (4).

4. The brake shoe according to claim 3, characterized in that: The mounting bracket is composed of a pair of elements, namely a fixing through-hole (6) and a matching protrusion (7), preferably passing through the through-hole.

5. Brake shoe according to any one of the preceding claims, characterized in that There is at least one protrusion (8) on the side of the back plate (5) of the composite brake pad (4) facing the composite brake pad.

6. Brake shoe according to any one of the preceding claims, characterized in that An element for resisting lateral force, preferably a protrusion (9), is formed on the surface of a composite brake block (1) used for casting the cast iron brake pad (3).

7. Brake shoe according to any one of the preceding claims, characterized in that The protrusion (12) of the key bridge (10) of the composite brake block (1) which is placed in the perforation (11) before casting the cast iron brake pad (3) is in a position to extend into the cast iron brake pad (3) after casting.

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