Composite double-layer brake pad and preparation method thereofTechnical Field
The invention relates to the technical field of automobile parts, in particular to a composite double-layer brake pad and a preparation method thereof.
Background
In the braking system of an automobile, a brake pad is the most critical safety part. With the rapid development of modern technology, the brake pads themselves, like the components of other braking systems, have been constantly developed and changed in recent years. Many novel high-performance brake pads appear on the market at present, but the brake performance is improved, and meanwhile, the great influence is generated on the living environment, and the emission of brake noise and harmful gas cannot be effectively controlled. The friction material used by the automobile brake pad used by people at present contains a plurality of heavy metal substances, including antimony, chromium, cadmium, copper, barium, copper and other heavy metals. In each braking process of the automobile, a small amount of heavy metal dust is released and accumulated in the environment to cause damage.
In addition, the existing brake pad also has the technical problems of poor heat conductivity, easy brittle fracture of corners, heat fading, high wearability and the like.
Chinese patent publication No. CN103409107A, published as 2013, 11.27, discloses a friction material for brake pads of a brake and a preparation process thereof, wherein the friction material comprises Kadeli resin, Twaron fiber, glass fiber, mineral fiber, graphite, molybdenum dioxide, sepiolite, barium sulfate, friction powder, tire powder, friction enhancer, potash feldspar, flame retardant and zircon sand; although some components with high wear resistance and high temperature resistance are added, for medium and heavy trucks, higher temperature than that of common passenger cars is generated in the braking process, and materials with higher wear resistance are needed, so that the medium and heavy trucks cannot have braking failure during braking, have poor high temperature resistance, or have serious braking performance reduction under high temperature conditions, and are difficult to meet the braking requirements of the medium and heavy trucks under the conditions of multiple slopes, multiple bends and the like.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the composite double-layer brake pad and the preparation method thereof, and the brake pad has the characteristics of sensitive braking, stable braking, no noise, comfortable foot feeling, environmental friendliness, good high-temperature heat fading resistance, good wear resistance, stable friction coefficient, long service life and the like.
The technical scheme of the invention is as follows: a composite double-layer brake pad comprises a steel backing and a brake pad body, wherein the brake pad body consists of a bonding heat-insulating layer and a friction layer;
wherein, the bonding heat insulation layer comprises the following components in parts by weight:
40-50 parts of steel fiber, 10-20 parts of nitrile rubber powder, 5-10 parts of phenolic resin, 5-10 parts of silicon dioxide, 2-5 parts of aramid fiber, 5-10 parts of iron oxide red and 2-5 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2-3 parts of aramid fiber, 6-7 parts of polyacrylonitrile preoxidized fiber, 2-4 parts of polypropylene fiber, 7-10 parts of ceramic fiber, 10-13 parts of calcium sulfate whisker, 18-20 parts of heavy calcium carbonate, 7-10 parts of electrode graphene, 3-5 parts of cashew nut oil friction powder, 2-3 parts of flake graphite and l-2 parts of zircon powder.
Preferably, the adhesive heat-insulating layer consists of the following components in parts by weight:
45-50 parts of steel fiber, 15-20 parts of nitrile rubber powder, 7-10 parts of phenolic resin, 5-10 parts of silicon dioxide, 2-5 parts of aramid fiber, 5-10 parts of iron oxide red and 2-5 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2-3 parts of aramid fiber, 6-7 parts of polyacrylonitrile preoxidized fiber, 2-4 parts of polypropylene fiber, 7-10 parts of ceramic fiber, 10-13 parts of calcium sulfate whisker, 18-20 parts of heavy calcium carbonate, 7-10 parts of electrode graphene, 3-5 parts of cashew nut oil friction powder, 2-3 parts of flake graphite and l-2 parts of zircon powder.
The invention also provides a preparation method of the composite double-layer brake pad, which comprises the following steps:
pouring the components adhered with the heat-insulating layer into a high-speed dispersing machine according to the following weight components, and stirring the components into a uniformly dispersed powdery composition; pouring the components of the friction layer into a high-speed dispersion machine, and stirring to obtain a uniformly dispersed powdery composition. Then taking out the material composition, and putting two materials into a finished product mold in a feeding mode: firstly, putting a friction layer material and flattening, then putting an adhesive heat insulation layer material and flattening, then compounding a steel backing, putting the compounded steel backing into a flat vulcanizing machine, keeping the compound steel backing for 3 to 6 minutes at the high temperature of 150 ℃ and under the pressure of 15MPa, and removing burrs to obtain the compound double-layer brake pad;
the adhesive heat-insulating layer comprises the following components in parts by weight:
40-50 parts of steel fiber, 10-20 parts of nitrile rubber powder, 5-10 parts of phenolic resin, 5-10 parts of silicon dioxide, 2-5 parts of aramid fiber, 5-10 parts of iron oxide red and 2-5 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2-3 parts of aramid fiber, 6-7 parts of polyacrylonitrile preoxidized fiber, 2-4 parts of polypropylene fiber, 7-10 parts of ceramic fiber, 10-13 parts of calcium sulfate whisker, 18-20 parts of heavy calcium carbonate, 7-10 parts of electrode graphene, 3-5 parts of cashew nut oil friction powder, 2-3 parts of flake graphite and l-2 parts of zircon powder.
Preferably, the friction coefficient of the brake pad is heat fading: 350 ℃ and heat fading is less than or equal to 0.08.
Preferably, the cumulative wear rate of the brake pad<1.0×107cm3/N.m。
Preferably, the noise AK2521 of the brake pad has a noise level of 8.0 or more and a hardness HRS of 60-80.
The invention has the beneficial effects that:
1. the brake pad has the characteristics of environmental protection, good high-temperature heat fading resistance, good noise reduction performance, stable friction coefficient, long service life, stable braking, good wear resistance and the like;
2. the bonding heat insulation layer plays the roles of fixing the friction layer, improving the strength of the friction layer and isolating high temperature, and is very favorable for the performance of the friction layer material;
3. the friction layer is compounded by a plurality of new fiber materials, particularly aramid fibers, pre-oxidized fibers and electrode graphite, so that the defects of the respective performances of the fiber materials can be mutually compensated, and the fiber materials can also cooperate to form high performances such as rapid heat dissipation, stable friction coefficient, reduction of brake pad deformation and the like;
4. in the working process, the brake pad forms a more excellent friction layer and a transfer film, so that the automobile brake is sensitive, the brake is stable, no brake scream is generated, the comfort performance is better, and the brake disc is not damaged in the braking process.
Detailed Description
The following further illustrates embodiments of the invention:
example 1
A composite double-layer brake pad comprises a steel backing and a brake pad body, wherein the brake pad body consists of a bonding heat-insulating layer and a friction layer;
wherein, the bonding heat insulation layer comprises the following components in parts by weight:
40 parts of steel fiber, 10 parts of nitrile rubber powder, 5 parts of phenolic resin, 5 parts of silicon dioxide, 2 parts of aramid fiber, 5 parts of iron oxide red and 2 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2 parts of aromatic fiber, 6 parts of polyacrylonitrile preoxidized fiber, 2 parts of polypropylene fiber, 7 parts of ceramic fiber, 10 parts of calcium sulfate whisker, 18 parts of ground calcium carbonate, 7 parts of electrode graphene, 3 parts of cashew nut oil friction powder, 2 parts of flake graphite and l parts of zircon powder.
Example 2
A composite double-layer brake pad comprises a steel backing and a brake pad body, wherein the brake pad body consists of a bonding heat-insulating layer and a friction layer;
wherein, the bonding heat insulation layer comprises the following components in parts by weight:
42 parts of steel fiber, 13 parts of nitrile rubber powder, 7 parts of phenolic resin, 8 parts of silicon dioxide, 3 parts of aramid fiber, 7 parts of iron oxide red and 4 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2 parts of aromatic fiber, 7 parts of polyacrylonitrile pre-oxidized fiber, 3 parts of polypropylene fiber, 8 parts of ceramic fiber, 11 parts of calcium sulfate whisker, 19 parts of ground calcium carbonate, 8 parts of electrode graphene, 4 parts of cashew nut oil friction powder, 3 parts of flake graphite and l parts of zircon powder.
Example 3
A composite double-layer brake pad comprises a steel backing and a brake pad body, wherein the brake pad body consists of a bonding heat-insulating layer and a friction layer;
wherein, the bonding heat insulation layer comprises the following components in parts by weight:
45 parts of steel fiber, 15 parts of nitrile rubber powder, 9 parts of phenolic resin, 8 parts of silicon dioxide, 4 parts of aramid fiber, 8 parts of iron oxide red and 4 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
3 parts of aromatic fiber, 7 parts of polyacrylonitrile pre-oxidized fiber, 4 parts of polypropylene fiber, 9 parts of ceramic fiber, 12 parts of calcium sulfate whisker, 20 parts of ground calcium carbonate, 9 parts of electrode graphene, 4 parts of cashew nut oil friction powder, 3 parts of flake graphite and 2 parts of zircon powder.
Example 4
A composite double-layer brake pad comprises a steel backing and a brake pad body, wherein the brake pad body consists of a bonding heat-insulating layer and a friction layer;
wherein, the bonding heat insulation layer comprises the following components in parts by weight:
50 parts of steel fiber, 20 parts of nitrile rubber powder, 10 parts of phenolic resin, 10 parts of silicon dioxide, 5 parts of aramid fiber, 10 parts of iron oxide red and 5 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
3 parts of aromatic fiber, 7 parts of polyacrylonitrile pre-oxidized fiber, 4 parts of polypropylene fiber, 10 parts of ceramic fiber, 13 parts of calcium sulfate whisker, 20 parts of ground calcium carbonate, 10 parts of electrode graphene, 5 parts of cashew nut oil friction powder, 3 parts of flake graphite and l parts of zircon powder.
Example 5
A preparation method of a composite double-layer brake pad comprises the following steps:
pouring the components adhered with the heat-insulating layer into a high-speed dispersing machine according to the following weight components, and stirring the components into a uniformly dispersed powdery composition; pouring the components of the friction layer into a high-speed dispersion machine, and stirring to obtain a uniformly dispersed powdery composition. Then taking out the material composition, and putting two materials into a finished product mold in a feeding mode: firstly, putting a friction layer material and flattening, then putting a heat insulation layer material and flattening, then compounding a steel backing, putting the compounded steel backing into a flat vulcanizing machine, keeping the compound steel backing for 6 minutes at the high temperature of 150 ℃ and under the pressure of 15MPa, and removing burrs to obtain the compound double-layer brake pad;
the adhesive heat-insulating layer comprises the following components in parts by weight:
40-50 parts of steel fiber, 10-20 parts of nitrile rubber powder, 5-10 parts of phenolic resin, 5-10 parts of silicon dioxide, 2-5 parts of aramid fiber, 5-10 parts of iron oxide red and 2-5 parts of cellulose fiber;
the friction layer comprises the following components in parts by weight:
2-3 parts of aramid fiber, 6-7 parts of polyacrylonitrile preoxidized fiber, 2-4 parts of polypropylene fiber, 7-10 parts of ceramic fiber, 10-13 parts of calcium sulfate whisker, 18-20 parts of heavy calcium carbonate, 7-10 parts of electrode graphene, 3-5 parts of cashew nut oil friction powder, 2-3 parts of flake graphite and l-2 parts of zircon powder.
The brake pad prepared by the embodiment has the characteristics of sensitivity, stable braking, no noise, comfortable foot feeling, environmental friendliness, good high-temperature heat fading resistance, good wear resistance, stable friction coefficient, long service life and the like. Through the improvement of the formula in the friction layer, the performance of the friction material of the brake pad is effectively improved, such as rapid heat dissipation, stable friction coefficient, reduction of the deformation of the brake pad and the like. The performance parameters to be achieved by the brake pad are as follows:
(1) coefficient of friction heat fade: at 350 ℃, heat fading is less than or equal to 0.08;
(2) cumulative wear rate<1.0×107cm3/N.m(GB5763-2008)；
(3) The noise level of the noise AK2521 is above 8.0;
(4) the hardness HRS is 60-80.
The foregoing embodiments and description have been presented only to illustrate the principles and preferred embodiments of the invention, and various changes and modifications may be made therein without departing from the spirit and scope of the invention as hereinafter claimed.