Brake lining and preparation method and application thereof

Abstract

The invention belongs to the technical field of brake linings, and particularly relates to a brake lining and a preparation method and application thereof. The brake lining provided by the invention comprises a friction block, and further comprises a first steel backing, a second steel backing and a third steel backing, and the friction block is arranged on one surface of the first steel backing; the second steel backing is arranged on the face, back to the friction block, of the first steel backing. The heat insulation layer is arranged between the first steel backing and the second steel backing; the friction block is made of a friction material; the friction material comprises aluminum nitride. In the using process of the brake lining, the temperature of the back face of the steel backing is low, the influence on the temperature of brake fluid is small, the temperature rise of the brake fluid is small, the brake fluid is protected in the high-load brake environment, the brake fluid is kept at the low temperature, and the running safety of a vehicle is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of brake linings, and in particular relates to a brake lining and a preparation method and application thereof. Background Art

[0002] Generally speaking, the friction material for automobile brake linings is a resin-based multi-component composite material, which is made of three main components: binder (resin and rubber), reinforcing fiber and friction performance modifier, and other ingredients through a series of manufacturing and processing processes. Its products have good friction coefficient and wear resistance, as well as certain heat resistance and mechanical strength. However, commercial vehicles, especially heavy-duty trucks, have the characteristics of heavy loads and more frequent braking. Resin-based composite materials are difficult to meet the requirements of higher friction performance and better temperature resistance. Therefore, high-performance powder metallurgy composite linings are developed to meet the needs of high-frequency braking of commercial vehicles.

[0003] The brake lining of a car generally consists of two parts, namely the friction material and the steel back. The steel back plays the role of supporting the friction material and is connected to the brake caliper. The brake fluid is the force transmission medium in the hydraulic brake system. It is located between the brake caliper and the master brake cylinder. Therefore, the heat during the use of the brake lining can be easily transferred to the brake fluid through the brake caliper and other components. If the temperature of the brake fluid is too high, its physical and chemical properties may change, such as lowering the boiling point and increasing the viscosity. These changes will affect the transmission efficiency of the brake fluid and the overall performance of the brake system. Especially in extreme cases, if the brake fluid boils and produces steam, it will cause the brake pedal to become soft and unable to transmit effective braking force to the brake caliper, thereby reducing the braking effect and affecting driving safety. During the use of existing automobile brake linings, the temperature of the back of the steel back in the brake lining is high, which easily causes the temperature of the brake fluid to rise, affecting driving safety. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the temperature of the back of the steel back of the existing automobile brake lining is high during use, which easily causes the temperature of the brake fluid to rise and affects driving safety. Thus, a brake lining and its preparation method and application are provided.

[0005] The present invention provides a brake lining, comprising a friction block and further comprising:

[0006] a first steel back, wherein the friction block is arranged on one surface of the first steel back;

[0007] A second steel back is arranged on a side of the first steel back facing away from the friction block;

[0008] A heat insulation layer is disposed between the first steel back and the second steel back;

[0009] The friction block is made of friction material;

[0010] The friction material includes aluminum nitride.

[0011] Preferably, the thermal conductivity of the thermal insulation layer is 0.2-1.0 W / (m·K).

[0012] Preferably, the thickness of the thermal insulation layer is 0.5-1.5 mm.

[0013] Preferably, the material of the heat insulation layer includes mica sheets.

[0014] Preferably, the mass content of aluminum nitride in the friction material is 3-9%.

[0015] Preferably, the friction material comprises, by mass percentage, 5-9% micro-carbon ferrochrome, 1-3% silicon oxide, 3-7% silicon carbide, 6-10% flake graphite, 7-11% graphite particles, 1-3% molybdenum disulfide, 3-9% aluminum nitride, and the remainder iron.

[0016] Optionally, the graphite particles are 20-80 mesh graphite particles.

[0017] Optionally, the mass content of carbon in the micro-carbon ferrochrome is less than 0.15%.

[0018] The present invention provides a method for preparing the brake lining described above, comprising the following steps:

[0019] 1) mixing and press-molding the friction material, and then placing the molded friction material on a first steel back for sintering to obtain a first steel back provided with a friction block;

[0020] 2) placing a heat insulation layer between the first steel back and the second steel back and connecting and fixing them to obtain the brake lining.

[0021] Optionally, the heat insulation layer is placed between the first steel back and the second steel back and connected and fixed by riveting.

[0022] Preferably, the mixing speed in step 1) is 50-100 rpm and the mixing time is 25-30 min;

[0023] The pressure of the press molding is 9-12Mpa, and the time of the press molding is 3-5s.

[0024] Preferably, in step 1), the sintering temperature is 1100-1200° C., and the sintering time is 90-120 min.

[0025] The present invention provides an application of the brake lining or the brake lining prepared by the preparation method of the brake lining in a locomotive brake device.

[0026] The technical solution of the present invention has the following advantages:

[0027] The brake lining provided by the present invention includes a friction block, and also includes: a first steel back, the friction block is arranged on one surface of the first steel back; a second steel back, arranged on the side of the first steel back facing away from the friction block; a heat insulation layer, arranged between the first steel back and the second steel back; the friction block is made of a friction material; and the friction material includes aluminum nitride. The present invention introduces aluminum nitride (AlN) with high thermal conductivity as an additive phase in the friction material for preparing the friction block, effectively improving the heat dissipation of the friction material, avoiding frequent braking under long downhill conditions, resulting in insufficient heat dissipation performance of the friction block and continuous temperature increase; a layer of heat insulation layer is interposed between the first steel back and the second steel back to block and reduce the heat conduction efficiency. By adding aluminum nitride to the friction material and setting the heat insulation layer in coordination, the heat dissipation performance of the friction block is improved, long-term high temperature is avoided, and the heat insulation performance between the brake linings is increased, and the heat of the brake lining is reduced to the back of the steel back, so that the temperature of the back of the steel back rises less and the temperature is lower, and then the temperature of the brake fluid rises less. The temperature of the back side of the steel back of the brake lining of the present invention is relatively low during use, which has little impact on the temperature of the brake fluid, causing the brake fluid temperature to rise less. The brake fluid is protected in a high-load braking environment, keeping the brake fluid at a relatively low temperature, thereby ensuring the driving safety of the vehicle.

[0028] The brake lining provided by the present invention has a heat insulation layer located between a first steel back and a second steel back, and the friction block is arranged on a side of the second steel back away from the heat insulation layer. The present invention arranges a second steel back between the heat insulation layer and the friction block, which not only supports the friction block, but also ensures that the overall structure of the brake lining is stable, is not prone to faults and falls off, and has a longer service life. At the same time, it can also assist the friction block in achieving good heat dissipation. When heat is transferred from the friction block to the second steel back, the second steel back provides more heat dissipation area to achieve good heat dissipation. The blocking of the heat insulation layer can further ensure that the temperature on the back side of the steel back is low, which has little effect on the temperature of the brake fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the three-dimensional structure of the brake lining of the present invention;

[0031] Figure numerals: 100 - friction block, 201 - first steel back, 202 - second steel back, 300 - heat insulation layer. DETAILED DESCRIPTION

[0032] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0033] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0034] The low carbon ferrochrome used in the embodiments and comparative examples of the present invention is of the grade FeCr69C0.10.

[0035] The graphite particles used in the examples and comparative examples of the present invention are 30-mesh graphite particles.

[0036] The first steel back 201 and the second steel back 202 used in the embodiment and the comparative example of the present invention are both Q235B carbon steel.

[0037] Example 1

[0038] This embodiment provides a brake lining, the structure of which is as follows Figure 1 As shown, it includes a friction block 100, and also includes: a first steel back 201, the friction block 100 is arranged on one side of the first steel back 201; a second steel back 202, arranged on a side of the first steel back 201 facing away from the friction block 100; a heat insulation layer 300, arranged between the first steel back 201 and the second steel back 202;

[0039] The friction block 100 is made of friction material; the friction material, by mass percentage, includes 7% micro-carbon ferrochrome, 2% silicon oxide, 5% silicon carbide, 8% flake graphite, 9% graphite particles, 2% molybdenum disulfide, 3% aluminum nitride, and the balance iron.

[0040] The heat insulation layer 300 is a mica sheet heat insulation layer 300 , the thermal conductivity of the heat insulation layer 300 is 0.5 W / (m·K), and the thickness of the heat insulation layer 300 is 0.5 mm.

[0041] This embodiment provides a method for preparing the above brake lining, comprising the following steps:

[0042] 1) Weigh the above friction material raw materials according to the amount, mix them at a speed of 50 rpm for 30 minutes, press-form them, the press-forming pressure is 9 MPa, the press-forming time is 4 seconds, and then place the formed friction material on the first steel back 201 and sinter them in a vacuum sintering furnace at a sintering temperature of 1100° C. for 120 minutes to obtain the first steel back 201 provided with the friction block 100;

[0043] 2) A mica sheet insulation layer 300 with a thickness of 0.5 mm and a thermal conductivity of 0.5 W / (m·K) is placed between the first steel back 201 and the second steel back 202, and the layers are formed by riveting to obtain the brake lining.

[0044] Example 2

[0045] This embodiment provides a brake lining, the structure of which is as follows Figure 1 As shown, it includes a friction block 100, and also includes: a first steel back 201, the friction block 100 is arranged on one side of the first steel back 201; a second steel back 202, arranged on a side of the first steel back 201 facing away from the friction block 100; a heat insulation layer 300, arranged between the first steel back 201 and the second steel back 202;

[0046] The friction block 100 is made of friction material; the friction material, by mass percentage, includes 9% micro-carbon ferrochrome, 1% silicon oxide, 7% silicon carbide, 6% flake graphite, 11% graphite particles, 1% molybdenum disulfide, 6% aluminum nitride, and the remainder iron.

[0047] The heat insulation layer 300 is a mica sheet heat insulation layer 300 , the thermal conductivity of the heat insulation layer 300 is 0.5 W / (m·K), and the thickness of the heat insulation layer 300 is 1.0 mm.

[0048] This embodiment provides a method for preparing the above brake lining, comprising the following steps:

[0049] 1) Weigh the above friction material raw materials according to the amount, mix them at a speed of 75 rpm for 27 minutes, press-form them, the press-forming pressure is 10 MPa, the press-forming time is 5 seconds, and then place the formed friction material on the first steel back 201 and sinter them in a vacuum sintering furnace at a sintering temperature of 1150° C. for 100 minutes to obtain the first steel back 201 provided with the friction block 100;

[0050] 2) A mica sheet insulation layer 300 with a thickness of 1.0 mm and a thermal conductivity of 0.05 W / (m·K) is placed between the first steel back 201 and the second steel back 202, and the layers are formed by riveting to obtain the brake lining.

[0051] Example 3

[0052] This embodiment provides a brake lining, the structure of which is as follows Figure 1 As shown, it includes a friction block 100, and also includes: a first steel back 201, the friction block 100 is arranged on one side of the first steel back 201; a second steel back 202, arranged on a side of the first steel back 201 facing away from the friction block 100; a heat insulation layer 300, arranged between the first steel back 201 and the second steel back 202;

[0053] The friction block 100 is made of friction material; the friction material, by mass percentage, includes 5% micro-carbon ferrochrome, 2% silicon oxide, 3% silicon carbide, 10% flake graphite, 7% graphite particles, 3% molybdenum disulfide, 9% aluminum nitride, and the balance iron.

[0054] The heat insulation layer 300 is a mica sheet heat insulation layer 300 , the thermal conductivity of the heat insulation layer 300 is 0.5 W / (m·K), and the thickness of the heat insulation layer 300 is 1.5 mm.

[0055] This embodiment provides a method for preparing the above brake lining, comprising the following steps:

[0056] 1) Weigh the above friction material raw materials according to the amount, mix them at a speed of 100 rpm for 25 minutes, press-form them, the press-forming pressure is 12 MPa, the press-forming time is 3 seconds, and then place the formed friction material on the first steel back 201 and sinter them in a vacuum sintering furnace at a sintering temperature of 1200° C. for 90 minutes to obtain the first steel back 201 provided with the friction block 100;

[0057] 2) A mica sheet insulation layer 300 with a thickness of 1.5 mm and a thermal conductivity of 0.5 W / (m·K) is placed between the first steel back 201 and the second steel back 202, and the layers are formed by riveting to obtain the brake lining.

[0058] Comparative Example 1

[0059] This comparative example provides a brake lining, which differs from Example 1 in that the friction material, by mass percentage, comprises 7% micro-carbon ferrochrome, 2% silicon oxide, 5% silicon carbide, 8% flake graphite, 9% graphite particles, 2% molybdenum disulfide, and the remainder iron.

[0060] Comparative Example 2

[0061] This comparative example provides a brake lining, which is different from Example 1 in that no heat insulation layer 300 is provided between the first steel back 201 and the second steel back 202 .

[0062] Comparative Example 3

[0063] This comparative example provides a brake lining, which differs from Example 1 in that no heat insulating layer 300 is provided between the first steel back 201 and the second steel back 202, and the friction material, in terms of mass percentage, comprises raw materials of 7% micro-carbon ferrochrome, 2% silicon oxide, 5% silicon carbide, 8% flake graphite, 9% graphite particles, 2% molybdenum disulfide, and the remainder iron.

[0064] Test Case

[0065] The brake pads of Examples 1-3 and Comparative Examples 1-3 were respectively assembled on the Link3900 test bench of an automobile brake test bench, and then a braking test was performed. The test method was as follows: initial braking temperature was 100°C, initial speed was 100km / h, braking deceleration was 1g, final speed was 0km / h, braking was repeated 10 times, and the temperature of the friction material, the temperature of the second steel back facing the insulation layer, and the temperature of the brake fluid were measured. The test results are shown in Table 1. The difference between the temperature of the second steel back facing the insulation layer and the temperature of the friction material was calculated as △1, and the difference between the temperature of the brake fluid and the temperature of the friction material was calculated as △2. The test results are shown in Table 1.

[0066] Table 1

[0067]

[0068]

[0069] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A brake lining, comprising a friction block, characterized in that: Also includes: a first steel back, wherein the friction block is arranged on one surface of the first steel back; A second steel back is arranged on a side of the first steel back facing away from the friction block; A heat insulation layer is disposed between the first steel back and the second steel back; The friction block is made of friction material; The friction material includes aluminum nitride.

2. The brake lining according to claim 1, characterized in that: The thermal conductivity of the thermal insulation layer is 0.2-1.0 W / (m·K).

3. The brake lining according to claim 1 or 2, characterized in that: The thickness of the heat insulation layer is 0.5-1.5 mm.

4. The brake lining according to any one of claims 1 to 3, characterized in that: The material of the heat insulation layer includes mica sheets.

5. The brake lining according to any one of claims 1 to 4, characterized in that: The mass content of aluminum nitride in the friction material is 3-9%.

6. The brake lining according to any one of claims 1 to 5, characterized in that: The friction material comprises, by mass percentage, 5-9% micro-carbon ferrochrome, 1-3% silicon oxide, 3-7% silicon carbide, 6-10% flake graphite, 7-11% graphite particles, 1-3% molybdenum disulfide, 3-9% aluminum nitride, and the balance iron.

7. A method for preparing a brake lining according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) mixing and press-molding the friction material, and then placing the molded friction material on a first steel back for sintering to obtain a first steel back provided with a friction block; 2) placing a heat insulation layer between the first steel back and the second steel back and connecting and fixing them to obtain the brake lining.

8. The method for preparing a brake lining according to claim 7, characterized in that: The mixing speed in step 1) is 50-100 rpm and the mixing time is 25-30 min; The pressure of the press molding is 9-12Mpa, and the time of the press molding is 3-5s.

9. The method for preparing a brake lining according to claim 7 or 8, characterized in that: In step 1), the sintering temperature is 1100-1200° C., and the sintering time is 90-120 min.

10. Use of the brake lining according to any one of claims 1 to 6 or the brake lining prepared by the method for preparing the brake lining according to any one of claims 7 to 9 in a locomotive brake device.

Images