CN204327815U - Floatation type brake pad - Google Patents

Abstract

The utility model discloses a floating brake pad, which comprises a back plate; a plurality of friction blocks arranged on the back plate; a disc spring arranged between the friction blocks and the back plate, and connecting the friction blocks in a floating manner The circlip on the first back plate; a positioning groove is formed on the back plate, and the disc spring is arranged in the positioning groove; the center of the brake disc matched with the brake pad is the center of the circle, The back plate is divided into several concentric rings, the lengths of the rings along the radial direction are equal, and the friction area of the friction block in each ring is no more than the reference average friction area compared with the reference average friction area. 15% of the friction area. The brake pad solves the problem of fatigue fracture caused by the instantaneous stress concentration of the existing disc spring during braking. The problem of eccentric wear of the block is eliminated, and the braking stability is greatly improved.

Description

floating brake pads

technical field

The utility model relates to a disc brake device applied to high-speed trains, in particular to a floating brake pad.

Background technique

In the train disc brake system, the brake pad is one of the key components. The braking force is applied to the brake pad through the brake caliper, so that the friction block of the brake pad contacts the brake disc to absorb kinetic energy. Make the train brake to stop. When the friction block is in contact with the brake disc and slides relative to each other, frictional heat will be generated on the sliding surface. Frictional heat causes thermal deformation of the two at the contact surfaces. Thermal deformation in turn affects the contact pressure distribution between the friction surfaces. For a given coefficient of friction, there is a certain critical sliding velocity of the brake disc, above which the nominally evenly distributed contact pressure becomes unstable, creating pressure and friction in localized areas on the sliding surface Concentration of heat. When the temperature stress caused by friction heat is higher than the yield limit of the material, a hot spot will be generated on the sliding friction surface, and this phenomenon is called thermoelastic instability. The generation of hot spots will aggravate the damage and wear of materials, and even cause low-frequency vibration of disc brakes, which are unfavorable to vehicle braking. With the gradual increase of vehicle speed, the requirements for braking performance are also gradually increased. Therefore, the problem of thermoelastic instability has attracted more and more attention.

In order to avoid the thermoelastic instability of the brake disc, it is first necessary to make the thermal deformation of the brake disc smaller, and the temperature gradient of the frictional heat generated during braking is smaller. An existing solution is to avoid eccentric wear of the friction block so that the frictional heat received by the friction block is relatively uniform. For example, Chinese patent document CN201606435U discloses a brake pad with an elastic floating structure. Disc springs are installed between them. When the high-speed brake pads brake, the angle of the friction block can be changed to increase the effective friction area between the friction block and the brake disc, thereby reducing the eccentric wear of the friction block and making the friction of the same size The frictional heat generated by the blocks is approximately equal. However, in actual application, this structure can only alleviate the phenomenon of eccentric wear, cracks, missing blocks, and defects of the friction block, but the deformation or cracks of the brake disc caused by frictional heat have not been solved, resulting in the brake disc The service life of the brake is low, and the braking performance of the brake is poor.

Therefore, how to solve the problem of thermoelastic instability of the brake disc and reduce the thermal deformation of the brake disc has become a technical problem to be solved urgently by those skilled in the art.

Utility model content

For this reason, the technical problem to be solved by the utility model lies in the problem that the thermoelastic instability of the existing train brake pads leads to poor braking performance and short service life of the brake disc, and then provides a method that can stably and reliably make the friction block Brake pads that fit well with the brake disc, avoid partial wear of the friction block to the greatest extent, and have less thermal deformation of the brake disc.

In order to solve the above technical problems, the floating brake pad of the present invention includes a floating brake pad, which includes a back plate, and a plurality of positioning holes are formed on the back plate; several friction A block, which includes a friction part, a positioning part inserted into the positioning hole, and a spherical support part disposed between the friction part and the positioning part, the spherical surface of the spherical support protruding in the direction of the positioning part ; a number of snap rings, the snap rings are snapped on the positioning part, and the friction block is connected to the back plate; it also includes a disc spring arranged between the friction block and the back plate , a positioning groove is formed on the back plate, and the disc spring is arranged in the positioning groove; taking the center of the brake disc matched with the brake pad as the center of the circle, the back plate is divided into several concentric The circular rings have the same length in the radial direction, and the friction area of the friction block in each circular ring is no more than 15% of the reference average friction area compared with the reference average friction area.

The reference average friction area of the utility model is the sum of the friction areas of several friction blocks on the back plate divided by the number of rings.

The sum of the distances between the center of gravity of the friction blocks located on both sides of the stress center line of the brake pad and the stress center line of the brake pad does not exceed 15% of the reference distance. Since the brake pad is installed on the brake pad support, and the brake caliper is connected to the brake pad support through a joint, the axis of the joint constitutes the stress center line of the brake pad described in the utility model. . The reference distance in the present invention is the sum of the distances between the center of gravity positions of all the friction blocks on the back plate and the stress center line of the brake pad divided by 2.

The sum of the distances from the centers of gravity of the friction blocks located on both sides of the stress center line of the brake pad to the stress center line of the brake pad is equal.

Since the brake pad is installed on the brake pad support, and the brake caliper is connected to the brake pad support through a joint, the axis of the joint constitutes the stressed center line of the brake pad described in the utility model.

The positioning groove is a cylindrical groove, and the diameter of the positioning groove is slightly larger than the diameter of the disc spring.

The friction block is formed by integral sintering of a friction body, a positioning piece and a support plate. The friction body is a cylindrical trimmed cylinder, which constitutes the friction part. The support plate is a thin plate with a spherical structure in the middle, and its spherical surface Part of the spherical support part is formed; one end of the positioning member forms a positioning part, the positioning part passes through the support plate and is inserted into the positioning hole, and the other end is connected with the friction body.

The side of the friction body facing the support plate is provided with several positioning bodies, and the support plate is provided with positioning holes matched with the positioning bodies.

The back plate is integrally formed with a dovetail structure on the plate surface away from the friction block.

Compared with the prior art, the above-mentioned technical solution of the utility model has the following advantages:

(1) The brake pad of the present utility model forms a floating connection structure by setting a disc spring between the friction block and the back plate. When the high-speed train is braking, the friction block can be freely adjusted to the best working surface through floating support. The effective braking area of the contact between the friction block and the brake disc is increased, and the eccentric wear phenomenon of the friction block is alleviated. At the same time, a positioning slot is set on the back plate, and the disc spring is installed in the positioning slot. On the one hand, it can protect the disc spring and prevent the problem of fatigue fracture caused by the instantaneous stress concentration of the disc spring during braking. At the same time, it reduces the distance between the back plate and the friction block. The gap between the friction blocks makes the swing of the friction block smaller and the braking stability is greatly improved. In addition, with the center of the brake disc matched with the brake pads as the center, the back plate is divided into several concentric rings, and the lengths of the rings along the radial direction are equal. Compared with the reference average friction area, the friction area of the friction block does not exceed 15% of the reference average friction area, that is, the friction areas in several equidistant rings are roughly equal. By changing the arrangement of friction blocks on the back plate cloth, so that the heat flux density of the brake disc is consistent, the friction heat generated by the friction block during braking is evenly distributed in the temperature rise of the brake disc, and the deformation or crack of the brake disc caused by the excessive temperature gradient of the existing brake pads is avoided. The phenomenon increases the service life of the brake disc and greatly improves the braking performance of the brake.

(2) The utility model is centered on the stress center line of the brake pad, and the sum of the distances between the friction blocks on the left and right sides and the stress center line of the brake pad does not exceed 15% of the reference distance compared with the reference distance. . This kind of brake pad can make the torque of the friction block on the brake pad and the center line of the brake pad roughly equal, avoiding the phenomenon of eccentric wear of the friction block, and the temperature rise of the friction block is more uniform, which further improves the braking stability and stability of the brake. service life.

(3) Further, the brake pad of the utility model locks the back plate and the friction block through the clip spring, so that the connection of each component is simple and compact. The friction part of the friction block is set as a cylindrical structure with chamfered edges, and multiple friction blocks mesh with each other to realize the horizontal locking of the friction blocks in the installation plane of the brake pad back plate.

Description of drawings

In order to make the content of the utility model easier to understand clearly, the utility model will be described in further detail below according to specific embodiments of the utility model in conjunction with the accompanying drawings, wherein

Fig. 1 is the structural representation of the floating brake pad of the present utility model;

Fig. 2 is the A-A direction sectional view of Fig. 1;

Fig. 3 is the structural representation of the friction block of the present utility model;

Fig. 4 is a schematic diagram of the assembly structure of the floating brake pad of the present invention;

The reference signs in the figure represent:

1-Backboard, 11-Positioning hole, 12-Positioning groove, 2-Friction block, 21-Friction part, 22-Spherical support part, 23-Positioning part, 231-Positioning slot, 3-Clip spring, 4-Disc Spring, 5-friction body, 51-positioning body, 6-positioning piece, 7-support plate, 71-positioning hole, 8-dovetail structure, A-brake disc, B-brake caliper, C-joint, D-brake support.

Detailed ways

The following embodiments will be used to further illustrate the present invention in conjunction with the accompanying drawings.

Fig. 1 and Fig. 2 are floating brake pads of the present invention, which include a backboard formed by splicing and connecting two backboards 1; several friction blocks 2 arranged on the backboard 1; A disc spring 4 arranged between the friction block 2 and the back plate 1 , and a clip spring 3 connecting the friction block 2 to the back plate 1 in a floating manner. As shown in Figure 1, with the virtual center of the backplane 1 as the center of the circle, the backplane 1 is divided into three rings (rings separated by arc-shaped dotted lines in the figure), and the three rings are The lengths of the circular rings along the radial direction are equal, and the friction area of the friction block 2 in each of the circular rings is no more than 12% of the reference average friction area compared with the reference average friction area. The friction areas are approximately equal. The arrangement structure of the friction blocks can make the heat flux density of the back plate consistent, and the friction heat generated by the friction blocks during braking can be evenly distributed on the back plate, which avoids the back plate caused by the excessive temperature gradient of the existing brake pads. Plate deformation or crack phenomenon, improve the service life of the brake pads.

Further, the brake pad of the present invention is centered on the stress centerline of the brake pad, and the distances from the friction blocks on both sides to the stress center line of the brake pad are approximately equal. As shown in Figure 4, since the brake pad A is installed on the brake pad support D, and the brake caliper B and the brake pad support D are connected through the joint C, the axis of the joint C constitutes the utility model. The new described brake pad stress center line. As shown in Figure 1, among the nine friction blocks on the brake pad, the distance between the upper friction block 2 and the stressed center line of the brake pad is (a+b+c+d+e), the right side The distance between the friction block 2 and the stressed centerline of the brake pad is (f+g+h+i), that is, (a+b+c+d+e)≈(f+g+h+i). This kind of brake pad can make the torque of the friction block on the brake pad and the center line of the brake pad equal, avoiding the phenomenon of eccentric wear of the friction block, and improving the braking stability; moreover, the temperature of the friction block increases more uniformly, and the brake The service life of the sheet is increased.

It can be seen from the thermal imaging experiment that when the ordinary brake pad is at 385kph, the temperature difference of the same disc surface of the brake disc reaches more than 400°C. When the local thermal stress of the brake disc exceeds the yield limit of the brake disc material itself, plastic deformation will occur, and at the same time Thermal stress is generated in the deformed part, causing cracks in the brake disc. The brake pads will also produce vibratory friction during the braking process, and the brake pads will bear greater frequent impacts, and the friction body is prone to block dropping and metal transfer. Under the same working condition, the above-mentioned brake pads of the present application are evenly heated on the disc surface, and the temperature difference does not exceed 150°C; the service life of the brake disc is greatly improved, and the safe use performance of the brake pads is greatly improved.

As shown in Figure 2, a plurality of positioning holes 11 for connecting the friction block 2 are formed on the back plate 1; preferably, a plurality of positioning holes 11 coaxial with the positioning holes 11 are formed on the back plate 1 The positioning groove 12, the disc spring 4 is placed on the positioning slot 12, the diameter of the positioning groove 12 is slightly larger than the outer diameter of the disc spring 4, which can prevent the disc spring 4 from causing fatigue due to instantaneous stress concentration during braking. At the same time, setting the positioning groove 12 on the back plate 1 can reduce the gap between the back plate 1 and the friction block 2, so that the swing of the friction block 2 is small, and the braking stability is greatly improved. In this embodiment, the back plate 1 is integrally formed with a dovetail structure 8 on the side away from the friction block 2 , and the dovetail structure 8 and the back plate 1 are formed by integral casting.

As shown in Figure 2, the friction block 2 includes a friction part 21, a positioning part 23 inserted into the positioning hole 11 and a spherical support part 22 arranged between the friction part 21 and the positioning part 23, the The spherical surface of the spherical support portion 22 protrudes toward the positioning portion 23 . In this embodiment, as shown in Figure 3, the friction block 2 is formed by integral sintering of a friction body 5, a positioning member 6 and a support plate 7, and the friction body 5 is a cylindrical trimmed cylinder, which constitutes the friction Part 21, a plurality of friction blocks mesh with each other to realize the locking of the friction blocks in the horizontal direction in the installation plane of the brake pad back plate; the support plate 7 is a thin plate with a spherical structure in the middle, and its shape is consistent with the shape of the friction body 5 , the spherical part of which constitutes the spherical support portion 22; one end of the positioning member 6 forms a positioning portion 23, and the positioning portion 23 passes through the support plate 7 and is inserted into the positioning hole 11, and the other end is connected to the friction body 5 connections. Wherein, the positioning portion 23 is formed with a positioning slot 231 .

In order to make it easier to position the friction body 5 and the support plate 7 during sintering, in this embodiment, the side of the friction body 5 facing the support plate 7 is provided with several positioning bodies 51, and the support plate 7 is provided with The positioning hole 71 matched with the positioning body 51 .

When the brake device is working, the brake pressure acts on the back plate 1 and is transmitted to the friction block 2 through several disc springs 4, and the several friction blocks 2 are smoothly attached to the brake disc for braking. Due to the disc spring 4 being in contact with the spherical support portion 22 of the friction block 2, the brake pad friction block can realize three-way micro-rotation, so that the friction working surface of the friction block is in contact with the brake disc to the greatest extent, preventing the friction block from Partial wear problem.

In other embodiments, the brake pads take the center of the brake disc as the center to divide the back plate 1 into several equidistant rings, and the friction block 2 in each ring The friction areas are equal; with the center line of the brake pad as the center, the sum of the distances between the friction blocks 2 on both sides and the center line of the brake pad is equal; the above scheme is the ideal state of the utility model. Considering the processing cost of the brake pad comprehensively, the brake pad takes the center of the brake disc as the center, divides the back plate 1 into several equidistant rings, and each of the rings The friction area of the friction block 2 is no more than 15% of the reference average friction area compared with the reference average friction area to ensure that the temperature gradient of the back plate is low; The distance between the friction block 2 and the stressed center line of the brake disc and the reference distance do not exceed 15% of the reference distance to ensure that the torque on both sides is roughly equal and avoid excessive eccentric wear.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (7)

1. a floatation type brake pad, it comprises,

Backboard (1), described backboard (1) forms multiple positioning hole (11);

Several brake pads (2), it comprises, friction part (21), the positioning part (23) of inserting described positioning hole (11) and the spherical support portion (22) be arranged between described friction part (21) and described positioning part (23), the sphere of described spherical support portion (22) protrudes to described positioning part (23) direction;

Several jump rings (3), described jump ring (3) is connected on described positioning part (23), is connected to by described brake pad (2) on described backboard (1); It is characterized in that:

Also comprise the disc spring (4) be arranged between described brake pad (2) and described backboard (1), described backboard (1) forms locating slot (12), described disc spring (4) is arranged in described locating slot (12); With the center of circle of the brake disc coordinated with described brake pad for the center of circle, described backboard (1) is divided into some donuts, described annulus length is radially equal, and the friction area of the described brake pad (2) in each described annulus is no more than 15% of benchmark average friction area up and down compared with benchmark average friction area.

2. floatation type brake pad according to claim 1, is characterized in that: the position of centre of gravity being positioned at the described brake pad (2) of brake lining center of effort line both sides is no more than 15% of reference range apart from the distance sum of described brake lining center of effort line up and down compared with reference range.

3. brake pad according to claim 2, is characterized in that: the position of centre of gravity being positioned at the described brake pad (2) of brake lining center of effort line both sides is equal apart from the distance sum of described brake lining center of effort line.

4., according to the arbitrary described floatation type brake pad of claim 1-3, it is characterized in that:

Described locating slot (12) is cylindrical groove, and the diameter of described locating slot (12) is slightly larger than described disc spring (4) diameter.

5. floatation type brake pad according to claim 1, is characterized in that:

Described brake pad (2) is by friction piece (5), locating piece (6) and dunnage (7) one sinter molding, described friction piece (5) is cylinder chamfered edge cylinder, it forms described friction part (21), described dunnage (7) for middle part be the thin plate of spherical structure, its land portions forms described spherical support portion (22); Shaping positioning part, described locating piece (6) one end (23), described positioning part (23) is inserted in described positioning hole (11) through described dunnage (7), and the other end is connected with described friction piece (5).

6. floatation type brake pad according to claim 5, is characterized in that:

Described friction piece (5) is provided with several positioning bodies (51) towards the one side of described dunnage (7), and described dunnage (7) is provided with the positioning hole (71) matched with described positioning body (51).

7. floatation type brake pad according to claim 1, is characterized in that:

Described backboard (1) is one-body molded on the plate face away from described brake pad (2) side dovetail configuration (8).