Background
Along with the development of economy in China, the speed of the urbanization process is increased remarkably, and the pressure and the demand of the increase of urban population on urban public transport are also increased remarkably. At present, the urban rail transit field mainly comprises transportation means such as subways, light rails, monorail and trams, wherein the transportation volume of the subways is the largest, but the cost is high, so that the urban rail transit is suitable for large-scale and ultra-large-scale cities; the light rail has moderate transportation volume and lower construction cost and maintenance cost, and is suitable for medium-sized cities; the tramcar has the advantages of minimum transportation volume and minimum construction cost, and is suitable for small-sized cities, micro-sized cities and lines with low transportation volume requirements. Comprehensively considering, the light rail will become the preferred scheme for the future medium-sized urban rail transit construction, and the construction scale will also increase year by year.
Along with the increase of the running speed and the load of the train, more and more rail trains adopt disc braking, and the kinetic energy of the train is converted into heat energy to be dissipated by clamping a brake disc and a brake pad to apply braking resistance during braking, so that the deceleration and the stop of the train are realized. The transmission ratio of the brake disc and the wheel reaches more than 5:1 when a part of urban rail trains brake, namely the rotating speed of the brake disc is far higher than the actual running speed of the train and can reach more than 5 times of the angular speed of the wheel, so that the relative linear velocity of the brake pad is high when the brake pad brakes, and the requirement on the brake pad is more severe. At present, a synthetic brake pad friction material used by an urban rail train is a high-molecular composite material, is easy to decompose at high temperature, the use temperature is generally not more than 350 ℃, the heat capacity is low, the heat conduction is poor, and the problems of smoke generation, eccentric wear, abnormal brake disc abrasion and the like are frequently generated in the use process; in addition, the rail transit industry has higher and higher requirements on environmental protection, and high polymer materials used by synthetic materials are easy to decompose, generate pungent odor, pollute the environment and influence the riding experience of passengers. Therefore, the synthetic brake pad is more difficult to meet the use requirement.
Disclosure of Invention
An object of the utility model is to provide a disc brake lining for urban rail train, replace synthetic material with powder metallurgy friction material, the distribution of friction particle has been optimized, friction particle passes through the resilient pad and supports, can effectively adjust the brake pressure of friction particle among the braking process, increase the area of contact of friction particle and brake disc, guarantee that the atress of friction particle is even, increase brake lining heat dissipation channel simultaneously, reduce and the surface temperature of homogenization brake lining and brake disc, avoid phenomenons such as brake lining eccentric wear and unusual wearing and tearing among the braking process, the braking is stable, long service life. Meanwhile, the friction particles are elastically riveted with the steel backing, so that the damage to the steel backing can be minimized in the using process, and the recycling of the disc brake pad steel backing for the urban railway train is facilitated.
The utility model provides a technical scheme as follows:
a disc brake pad for an urban railway train comprises a steel backing 1 and a plurality of friction particles 2; the steel back 1 is cast and formed in a butterfly-shaped symmetrical structure, a plurality of grooves 11 are distributed on one side of a friction surface of the steel back 1, and rivet grooves 12 are formed in positions, corresponding to the grooves 11, on one side of a non-friction surface on the other side of the non-friction surface; the number of the grooves 11 is gradually increased from inside to outside along the radial direction of the steel backing 1;
a rivet hole 13 penetrating the other side of the steel backing 1 is formed in the center of the groove 11, and two positioning holes 14 are symmetrically formed in the center of the rivet hole 13;
the friction particles 2 comprise a back plate 21 and a friction material 22; the friction material 22 is sintered on the outer side of the back plate 21, and the friction material 22 and the back plate 21 are sintered into an integral structure; the outer contour of the friction material 22 is not larger than the outer contour of the back plate 21;
the friction particle 2 is provided with a friction particle central hole 23, and two positioning columns 24 matched with the positioning holes 14 are arranged on the inner side surface of the back plate 21 in central symmetry relative to the friction particle central hole 23;
each groove 11 is provided with a friction particle 2; the edge distance between the adjacent friction particles 2 is 2-5 mm;
an elastic gasket 3 is arranged between the friction particles 2 and the bottom of the groove 11, and the friction particles 2 and the steel backing 1 are fixedly riveted through rivets 4; the two positioning columns 24 are positioned in the positioning holes 14 and limit the circumferential swing of the friction particles 2 to be 5-10 degrees; and the back plate 21 is partially or entirely sunk into the recess 11.
The shape of the groove 11 is circular, oval or polygon with no less than five sides, and correspondingly, the friction particles 2 are circular, oval or polygon with no less than five sides.
The elastic gasket 3 is made of high-temperature-resistant stainless steel and is disc-shaped.
By the above-mentioned the technical scheme provided by the utility model, the embodiment of the utility model provides a pair of disc brake pad for urban rail train replaces synthetic material with powder metallurgy friction material, the distribution of friction particle has been optimized, friction particle passes through the gasket support, can effectively adjust the brake pressure of the in-process friction particle of braking, increase the area of contact of friction particle and brake disc, it is even to guarantee the atress of friction particle, increase brake pad heat dissipation channel simultaneously, reduce and homogenize the surface temperature of brake pad and brake disc, avoid phenomenons such as brake pad eccentric wear and unusual wearing and tearing among the braking process, the braking is stable, long service life. Meanwhile, the friction particles are elastically riveted with the steel backing, so that the damage to the steel backing can be minimized in the using process, and the recycling of the disc brake pad steel backing for the urban railway train is facilitated.
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiment of the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
As shown in fig. 1 to 2, a disc brake pad for an urban railway train comprises a steel backing 1, a plurality of friction particles 2, a plurality of elastic pads 3 and rivets 4 for connecting and fixing.
As shown in fig. 3 and 4, the steel backing 1 is cast and formed in a butterfly-shaped symmetrical structure, and the cast and processed steel backing 1 is simple in process, low in cost, subjected to surface corrosion prevention treatment, reusable after the friction particles 2 are worn to the limit, and capable of increasing economic benefits. A plurality of grooves 11 are distributed on one side of the friction surface of the steel back 1, and rivet grooves 12 are arranged on one side of the other side of the non-friction surface, corresponding to the grooves 11; the number of the grooves 11 is gradually increased from inside to outside along the radial direction of the steel backing 1; as in the example of fig. 1, 4, 5, and 6 are provided in sequence from inside to outside, and other combinations are also possible in specific use, which are all within the scope of the present patent. Meanwhile, the shape of the groove 11 is circular, oval or polygonal with the number of sides not less than five.
As shown in fig. 3 and 4, a rivet hole 13 penetrating through the other side of the steel backing 1 is formed in the center of the groove 11, and two positioning holes 14 are formed in the center of the rivet hole 13 symmetrically; the positioning hole 14 is a through hole which penetrates through the other side of the steel backing 1, and is convenient to machine and not a through hole.
As shown in fig. 5, the friction particle 2 includes a back plate 21 and a friction material 22; the friction material 22 is sintered on the outer side of the back plate 21, and the friction material 22 and the back plate 21 are sintered into an integral structure; specifically, two process holes 25 are further formed in the back plate 21, and the process holes 25 are centrosymmetric with respect to the friction particle central hole 23. And the positioning function is realized during sintering. The outer contour of the friction material 22 is not larger than the outer contour of the back plate 21; i.e., both have the same cross-section, and the cross-sectional area of the friction material 22 should be no greater than the cross-sectional area of the back plate 21. The friction material 22 is made of sintered powder metallurgy material, and the specific materials and processes are common knowledge and will not be described in detail.
The friction particle 2 is provided with a friction particle center hole 23, and two positioning columns 24 matched with the positioning holes 14 are arranged on the inner side surface of the back plate 21 and are centrosymmetric about the friction particle center hole 23. The positioning column 24 is matched with the positioning hole 14 to ensure that the rivet hole 13 and the friction particle central hole 23 are coaxial, and the friction particle 2 has a swing rotation angle of 5-10 degrees in the axial direction along the axis of the friction particle central hole 23 to ensure effective fit of the friction material 22 and the brake disc; the friction particles 2 correspond to the shape of the grooves 11, and the friction particles 2 are circular, elliptical or polygonal with the number of sides not less than five. That is, the back plate 21 and the friction material 22 have the same shape, and are circular, oval or polygonal with not less than five sides.
When in installation, each groove 11 is provided with one friction particle 2; the edge distance between the adjacent friction particles 2 is 2-5 mm; an elastic gasket 3 is arranged between the friction particles 2 and the bottom of the groove 11, and the friction particles 2 and the steel backing 1 are fixedly riveted through rivets 4; the two positioning columns 24 are positioned in the positioning holes 14 and limit the circumferential swing of the friction particles 2 to be 5-10 degrees; and the back plate 21 is partially or entirely sunk into the recess 11. Increasing the effective wear thickness of the friction material 22 and reducing the tangential forces experienced by the rivet 4.
As shown in fig. 6, the elastic pad 3 is made of a high temperature resistant stainless steel material, specifically, 07Cr17Ni7Al material, and is disc-shaped. The structure of the gasket can be divided into a gasket top 31, a gasket central hole 32 and a gasket bottom 33 which are all round. The elastic pad 3 plays an elastic buffering role between the friction particles 2 and the steel backing 1, the top 31 of the pad is contacted with the back plate 21 of the friction particles 2, and the bottom 33 of the pad is contacted with the groove 11 of the steel backing 1. During braking, the brake pad is adjusted along the thickness direction of the steel backing 1 according to the stress change, so that the impact force of the brake pad and the brake disc during braking is reduced.
As shown in fig. 7, the rivet 4 is of a unitary structure; the structure of the rivet can be divided into three parts, namely a rivet top part 41, a rivet column 42 and a rivet bottom part 43, wherein each part is cylindrical. The rivet bottom 43 is in contact with the rivet groove 12, the rivet column 42 sequentially penetrates through the rivet hole 13 of the steel backing 1, the gasket center hole 32 and the friction particle center hole 23, the contact surface between the back plate 21 and the friction material 22 protrudes by 1.5-2.5 mm when the rivet top 31 is installed, and the rivet top 31 is flattened and matched with the back plate 22 after riveting.
During riveting, firstly, a rivet column 42 of a rivet 4 penetrates through a rivet hole 13 of the steel backing 1 along one side of the non-friction surface of the steel backing 11 until a rivet bottom 43 is contacted with the bottom of a rivet groove 12; repeating the steps for a plurality of times until all the rivets 4 are placed in place, and turning the steel back 1 to enable the friction surface to face upwards; secondly, sequentially placing each elastic gasket 3 into the groove 11 on one side of the friction surface, and contacting the bottom 33 of each elastic gasket 3 with the bottom of the groove 11 of the steel backing 1; then each friction particle 2 is placed above the elastic gasket 3, the positioning column 24 is arranged in the positioning hole 14, and the friction particles 2 are adjusted to enable the friction particle central hole 23 to be coaxial with the rivet hole 13 and the rivet column 42; the bottom surface of the back plate 21 is contacted with the top 31 of the elastic gasket 3; ensuring that the top part 41 of the rivet 4 exceeds the contact surface of the back plate 21 and the friction material 22 by 1.5-2.5 mm; the top 41 of the rivet 4 is flattened to fit the back plate 22. The elastic connection of the steel backing 1, the friction particles 2 and the elastic gasket 3 is realized.
By the technical scheme that above-mentioned utility model provided can see out, it has following advantage:
1. the friction particles 2 are connected with the steel backing 1 through the elastic gaskets 3, and the rivets 4 are fastened, so that impact work generated when the brake pad is contacted with the brake disc can be absorbed, and the impact force of the brake pad and the brake disc is reduced;
2. the elastic pad 3 supports the friction particles 2, and each friction particle 2 can be adjusted along the thickness direction of the steel backing 1 along with the change of braking pressure during braking, so that the running-in time is shortened, and the contact area between a friction material and a brake disc is increased;
3. the elastic pad 3 can absorb the vibration generated by the brake pad during braking, thereby being beneficial to reducing the noise in the braking process;
4. the friction particles 2 rotate along the center in a proper axial direction, so that the contact balance between the brake pad and the brake disc can be automatically leveled, the uniform contact between the friction material and the brake disc is increased, and the uneven abrasion of the brake pad is reduced;
5. the gaps between the adjacent friction particles 2 are beneficial to the circulation of air, the heat generated by the contact friction between the friction material and the brake disc is dissipated, and the temperature of the brake pad and the brake disc is reduced;
6. the back plate part of the friction particles 2 is sunk into the steel back groove, so that the effective abrasion thickness can be increased, and the tangential force borne by the rivet can be reduced;
7. the friction area of the brake pad is increased by approximate times along the radial direction and the friction radius, so that the same braking energy borne by a unit friction material during braking is ensured, the eccentric wear of the brake pad is reduced, and the service life of the brake pad is prolonged.
The above description is only for the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are all covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.