JP6906415B2 - Brake pads and disc brakes - Google Patents

Description

The present invention relates to brake pads and disc brakes.

Grooves are formed in the lining of the brake pads (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2011-214628 Japanese Unexamined Patent Publication No. 11-270599

Disc brakes are required to suppress the generation of abnormal noise.

An object of the present invention is to provide a brake pad and a disc brake capable of suppressing the generation of abnormal noise.

In order to achieve the above object, the present invention has a structure in which the lining is provided with an arcuate groove having a partial shape of an annulus centered at the center of the lining.

According to the present invention, the generation of abnormal noise can be suppressed.

The plan view which shows the disc brake which concerns on embodiment. The plan view which shows the disc, the support member and the brake pad of the disc brake which concerns on embodiment. The front view which shows the brake pad in a new state of Example 1 which concerns on embodiment. The plan view which shows the brake pad in a new state of Example 1 which concerns on embodiment. The front view which shows the brake pad in a new state of Example 2 which concerns on embodiment. The front view which shows the brake pad in a new state of Example 3 which concerns on embodiment. The front view which shows the brake pad in a new state of Example 4 which concerns on embodiment. The graph which shows the natural frequency change rate with respect to the lining total length ratio of the arcuate groove radius of the brake pad of Example 1 which concerns on embodiment.

The embodiment will be described with reference to the drawings. The disc brake 1 according to the present embodiment shown in FIG. 1 is attached to a vehicle such as an automobile, and applies frictional resistance to a disc 10 rotating together with a wheel (not shown) to be braked to brake the rotation of the wheel. Is what you do. In the following, the axial direction of the disc 10 is the disc axial direction, the rotation direction of the disc 10 is the disc rotation direction, and the direction of the line passing through the disc rotation direction center of the disc brake 1 among the radial directions of the disc 10 is the disc radial direction. Each is called. Further, in the disc radial direction, the direction away from the center of the disc 10 is referred to as the outside in the disc radial direction, and the direction approaching the center of the disc 10 is referred to as the inside in the disc radial direction.

As shown in FIG. 1, the disc brake 1 includes the above-mentioned disc 10, a support member 11 that straddles the outer peripheral side of the disc 10 in the disc axial direction and is attached to a non-rotating portion of the vehicle, and the disc axial direction of the disc 10. A pair of brake pads 12 that are arranged to face each other on both sides of the disc 10 and are supported by the support member 11, and a caliper 14 that is slidably attached to the support member 11 and presses the pair of brake pads 12 on both sides of the disc 10. I have.

As shown in FIG. 2, the support member 11 is an integrally molded product having a mirror-symmetrical shape, and has a pair of support portions 20, a mounting base portion 21, and an outer beam portion 22. The pair of support portions 20 are separated from each other. The mounting base portion 21 connects the pair of support portions 20 on one side. The outer beam portion 22 connects the pair of support portions 20 on the other side. In the support member 11, the mounting base portion 21 is mounted on the non-rotating portion of the vehicle.

In the state of being attached to the non-rotating portion of the vehicle, the pair of supporting portions 20 straddle the outer peripheral side of the disc 10 in the disc axial direction, and the pair of supporting portions 20 are separated from each other in the disc rotating direction. Is placed. Further, in the state of being mounted on the non-rotating portion of the vehicle, the support member 11 has a mounting base portion 21 extending in the disc rotation direction and an inner portion of the pair of support portions 20 on one side in the disc axial direction in the disc radial direction. Connect each other. Further, in the state of being attached to the non-rotating portion of the vehicle, the support member 11 has an outer beam portion 22 extending in the disk rotation direction and an inner portion of the pair of support portions 20 on the other side in the disc axial direction in the disc radial direction. Connect each other. The mounting base portion 21 and the outer beam portion 22 are arranged on both sides in the disc axial direction with respect to the disc 10. Here, the mounting base portion 21 is arranged inside the disc 10 in the vehicle width direction (hereinafter, referred to as the inner side). Further, the outer beam portion 22 is arranged outside the disc 10 in the vehicle width direction (hereinafter, referred to as the outer side).

The pair of brake pads 12 are arranged on both sides of the disc 10 in the disc axial direction, and both ends in the disc rotation direction are supported by the pair of support portions 20. While the pair of brake pads 12 are supported by the pair of support portions 20, the movement in the disc rotation direction and the disc radial direction is restricted, and the pair of brake pads 12 can move in the disc axial direction.

As shown in FIG. 1, the caliper 14 is a bottomed tubular cylinder portion that slidably supports a piston (not shown) in the disc axial direction and is arranged on the inner side of the brake pad 12 on the side opposite to the disc 10. 31 and a bridge portion 32 extending across the outer peripheral portion of the disc 10 from the outside in the disc radial direction of the cylinder portion 31, and a brake pad 12 on the outer side from the opposite side to the cylinder portion 31 of the bridge portion 32. It has a caliper main body 35 having a claw portion 33 extending so as to face the disc 10 on the opposite side, and a pair of arm portions 34 protruding from the cylinder portion 31 on both sides in the disc rotation direction.

The caliper 14 is a pair of disc path portions 38 arranged outside the disc 10 of the pair of support portions 20 of the support member 11 by a pair of pins 36 attached to the pair of arm portions 34 of the caliper main body 35. Is supported by. In the state of being supported by the support member 11 in this way, the caliper main body 35 is restricted from moving in the disc rotation direction and the disc radial direction, and can move in the disc axial direction.

When the brake hydraulic pressure is introduced between the cylinder portion 31 and the piston (not shown) by the brake operation by the brake pedal, the hydraulic pressure acts on the piston to generate a propulsive force in the direction of the disc 10. Then, as the piston moves in the direction of the disc 10, the brake pad 12 on the inner side is moved with respect to the support member 11 and the disc 10 in the disc axial direction and pressed against the disc 10.

Further, by the reaction force of this pressing, the caliper main body 35 moves to the inner side so as to move the claw portion 33 to the disc 10 side, and the brake pad 12 on the outer side is moved to the support member 11 and the disc 10 by the claw portion 33. And move it in the direction of the disc axis and press it against the disc 10.

As described above, the pair of brake pads 12 are pressed against the disc 10. Then, the pair of brake pads 12 will try to move to the disc rotation direction outlet side integrally with the disc 10, and the torque of the pair of brake pads 12 generated at this time will be mainly applied to the disc rotation direction outlet side of the support member 11. Support part 20 receives.

Further, when the piston (not shown) separates from the disc 10 after the brake operation by the brake pedal is released, the brake pad 12 separates from the disc 10 due to the vibration of the disc 10.

The pair of brake pads 12 are common parts. As shown in FIGS. 3 and 4, the brake pad 12 has a mirror-like shape, and has a plate-shaped back plate 51 and a lining 52 attached to one surface side of the back plate 51 in the plate thickness direction. Have. The brake pad 12 is supported by the support member 11 shown by the alternate long and short dash line in FIG. 3 on the back plate 51, and the lining 52 arranged on the disc 10 side of the back plate 51 contacts the disc 10 during braking. Let me.

The back plate 51 has a main plate portion 55 to which the lining 52 is attached, and a pair of convex portions 56 that project from both ends of the main plate portion 55 in the longitudinal direction in opposite directions along the longitudinal direction. .. Each of the pair of convex portions 56 has a torque transmission portion 57 that transmits braking torque to the support member 11 at an inner portion in the radial direction of the disc. The main plate portion 55 has torque transmission portions 58 that transmit braking torque to the support member 11 on both sides in the disk rotation direction. These torque transmission portions 58 are arranged inside the pair of convex portions 56 in the disc radial direction. In other words, the back plate 51 has torque transmission portions 57 and 58 that transmit braking torque to the support member 11 at both ends in the disk rotation direction.

Here, each of the pair of support portions 20 of the support member 11 has a pair of pad support portions 60 arranged on both sides of the disc 10 in the disc axial direction. These four pad support portions 60 have a common shape, and the pad support portions 60 arranged on the inner side of the disc 10 face each other in the disc rotation direction, and the pads are arranged on the outer side of the disc 10. The support portions 60 also face each other in the disk rotation direction.

The pad support portion 60 has a support recess 61 that is recessed inward in the disc rotation direction toward the outside in the disc rotation direction, and the support recess 61 accommodates the convex portion 56 of the brake pad 12. The support recess 61 has a torque receiving portion 62 whose inner side in the disc radial direction supports the torque transmitting portion 57 on the inner side in the disc radial direction of the convex portion 56 and receives the braking torque of the brake pad 12 from the torque transmitting portion 57. It has become. Further, the pad support portion 60 has a torque receiving portion 63 that receives the braking torque of the brake pad 12 from the torque transmission portion 58 of the brake pad 12 inside the support recess 61 in the disc radial direction.

The lining 52 includes an arcuate groove 71 having a partial shape of an annulus centered at the center of the lining 52. The arc-shaped groove 71 is recessed from the tip surface 52a on the side opposite to the back plate 51 of the lining 52 toward the back plate 51, and is composed of a pair, that is, two arc-shaped groove portions 72.

One groove portion 72 is arranged on one side in the disc rotation direction with respect to the central portion of the lining 52, has an arc shape centered on the central portion of the lining 52, and has the lining 52 in the disc radial direction. It penetrates. The other groove portion 72 is arranged on the other side in the disc rotation direction from the central portion of the lining 52, has an arc shape centered on the central portion of the lining 52, and has the lining 52 in the disc radial direction. It penetrates.

The pair of groove portions 72 are centered on the center position in the length direction of the back plate 51 of the line connecting the torque transmission portions 57 and 58 on one side in the disk rotation direction and the torque transmission portions 57 and 58 on the other side in the disk rotation direction. It has an arc shape with the same diameter. Specifically, the pair of groove portions 72 have an arc shape having the same diameter centered on the center position of a line connecting the inner surfaces 57a in the disc radial direction arranged on the same plane of the torque transmission portions 57 on both sides in the disc rotation direction. be. In the pair of groove portions 72, the wall surface 72a on the large diameter side forms a part of the cylindrical surface along the thickness direction of the lining 52, and the wall surface 72b on the small diameter side also forms a cylindrical surface along the thickness direction of the lining 52. It has a partial shape of. The pair of groove portions 72 have the same radius between the wall surfaces 72a on the large diameter side, and the same radius between the wall surfaces 72b on the small diameter side.

The radius of the arcuate groove 71 is 0.3 to 0.35 times the total length L of the lining 52 in the disk rotation direction. Specifically, in the arcuate groove 71, the radius of the wall surface 72a on the large diameter side of the pair of arcuate groove portions 72 is 0.3 to 0.35 times the total length L of the lining 52. More specifically, here, the radius of the wall surface 72a on the large diameter side of the pair of arcuate groove portions 72 is 0.325 times the total length L of the lining 52, and the radius of the wall surface 72b on the small diameter side is the total length of the lining 52. It is 0.3 times L.

The lining 52 connects the torque transmission portions 57, 58 on one side in the disk rotation direction and the torque transmission portions 57, 58 on the other side in the disk rotation direction, specifically, the surfaces 57a of the torque transmission portions 57 at both ends. One linear straight groove (groove) 75 is formed in the radial inner range of the disk than the wire and in the radial inner range of the arcuate groove 71 than the arcuate groove 71. The straight groove 75 is recessed from the tip surface 52a of the lining 52 toward the back plate 51. The straight groove 75 extends in the radial direction of the disc, extends to the end surface of the lining 52 on the inner side in the radial direction of the disc, and opens inward in the radial direction of the disc. The straight groove 75 has a pair of wall surfaces 75a on both sides in the disc rotation direction, and has end faces 75b on the outer side in the disc radial direction. Both the pair of wall surfaces 75a and the end faces 75b are flat surfaces along the thickness direction of the lining 52.

The straight groove 75 is formed near the center of the lining 52 in the disc rotation direction, specifically, at the center position. Therefore, in the straight groove 75, the pair of wall surfaces 75a on both sides in the disc rotation direction are arranged at positions equidistant from the center position in the disc rotation direction of the lining 52, respectively. The straight groove 75 is arranged on a line in which end faces 75b on the outer side in the radial direction of the disc connect the faces 57a of the torque transmission portions 57 at both ends.

The lining 52 connects the torque transmission portions 57, 58 on one side in the disk rotation direction and the torque transmission portions 57, 58 on the other side in the disk rotation direction, specifically, the surfaces 57a of the torque transmission portions 57 at both ends. Two linear straight grooves (grooves) 76 having the same shape are formed in the radial inner range of the arcuate groove 71 than the arcuate groove 71 on the outer side in the disc radial direction from the wire. Each of these straight grooves 76 is recessed from the tip surface 52a of the lining 52 toward the back plate 51. All of these straight grooves 76 extend in the disc radial direction, extend to the end surface of the lining 52 on the outer side in the disc radial direction, and open outward in the disc radial direction. Each of these straight grooves 76 has a pair of wall surfaces 76a on both sides in the disc rotation direction, and has end faces 76b on the inner side in the disc radial direction. Both the pair of wall surfaces 76a and the end faces 76b are flat surfaces along the thickness direction of the lining 52.

All of these straight grooves 76 are formed at positions equidistant from the central position of the lining 52 in the disc rotation direction. These straight grooves 76 are parallel to the straight grooves 75, and are longer in the disc radial direction than the straight grooves 75. In these straight grooves 76, the distance between the pair of wall surfaces 76a on both sides in the disk rotation direction is the same as the distance between the pair of wall surfaces 75a of the straight groove 75. These straight grooves 76 are arranged on a line in which end surfaces 76b on the inner side in the radial direction of each disk connect the surfaces 57a of the torque transmission portions 57 at both ends. That is, the surfaces 57a of the torque transmission portions 57 on both sides, the end faces 75b of the straight groove 75, and the end faces 76b of the straight grooves 76 on both sides are arranged on the same plane.

The two groove portions 72 of the arcuate groove 71, the one straight groove 75, and the two straight grooves 76 are all at the same depth from the tip surface 52a of the lining 52 when new to the vicinity of the back plate 51. It is formed and is formed deeper than 1/2 the thickness of the lining 52 when it is new.

The lining wears and its thickness decreases as it repeatedly contacts the disc for braking. Then, the natural frequency (natural value) of the vibration of the brake pad changes. If the natural frequency of the vibration of the brake pad changes due to the decrease in the thickness of the lining over time in this way, abnormal noise may be generated.

On the other hand, the brake pad 12 according to the embodiment has the natural frequency of vibration when the lining 52 is provided with the arcuate groove 71 and when the thickness of the lining 52 is worn to half from the new state. Suppress change. As a result, abnormal noise generated by changes over time is suppressed.

That is, in the new state and the worn state in which the thickness of the lining 52 is worn to half from the new state, the natural frequency of the primary bending of the vibration of the brake pad 12, the natural frequency of the secondary bending and the natural vibration of the twist. The portion where the number changes greatly is the position of the arcuate groove 71, and this portion is made into a space as the arcuate groove 71. As a result, the rigidity of the back plate 51 becomes dominant in each of the natural vibration modes of the primary bending, the secondary bending and the torsion. As a result, the change in the natural frequency can be reduced regardless of before and after the lining 52 is worn.

The above effects were confirmed by simulating nine types of brake pads with different lining grooves using the finite element method.

The first embodiment is the brake pad 12 in which an arcuate groove 71, one straight groove 75, and two straight grooves 76 are formed in the lining 52, and the second embodiment is as shown in FIG. This is a brake pad in which only the point that the straight groove 75 is not formed in the lining 52 is changed with respect to the first embodiment. In other words, in the second embodiment, only the arcuate groove 71 and the two straight grooves 76 are formed as grooves in the lining 52. As shown in FIG. 6, the third embodiment is a brake pad in which only the point that two straight grooves 76 are not formed in the lining 52 is changed from the first embodiment. In other words, the third embodiment is a brake pad. Only an arcuate groove 71 and one straight groove 75 are formed as grooves on the lining 52. As shown in FIG. 7, the fourth embodiment is a brake pad obtained by changing only the point that one straight groove 75 and two straight grooves 76 are not formed in the lining 52 with respect to the first embodiment, in other words. For example, in the fourth embodiment, only the arcuate groove 71 is formed as a groove in the lining 52.

Comparative Example 1 is a brake pad in which only the point that the arcuate groove 71 is not formed in the lining 52 is changed with respect to the first embodiment, and Comparative Example 2 is a brake pad in which the arcuate groove 71 is formed in the lining 52 with respect to the first embodiment. It is a brake pad changed only in that it does not form one straight groove 75, and in Comparative Example 3, the arcuate groove 71 and the two straight grooves 76 are not formed in the lining 52 with respect to the first embodiment. It is a brake pad in which only points are changed, and in Comparative Example 4, as compared to Example 1, only one linear groove penetrating in the disc radial direction is provided in the center of the lining 52 in the longitudinal direction as a groove in the lining 52. It is a brake pad in which only the formed points are changed, and Comparative Example 5 is a brake pad in which only the point where no groove is formed in the lining 52 is changed with respect to the first embodiment.

Then, in each of Examples 1 to 4 and Comparative Examples 1 to 5, the primary bending of the lining 52 was performed when the lining 52 was new (A) with a thickness of 9.5 mm and when it was worn (B) with a thickness of 4.75 mm. The natural frequency, the natural frequency of secondary bending, and the natural frequency of torsion were calculated by simulation. Here, the natural frequency of the primary bending, the natural frequency of the secondary bending, and the natural frequency of the twist are natural frequencies that appear as abnormal sounds at a frequency of 10 kHz or less, which is particularly offensive to humans. The results of Examples 1 to 4 are shown in Table 1, and the results of Comparative Examples 1 to 5 are shown in Table 2.

In Tables 1 and 2, the natural vibration mode 1 indicates the natural frequency of the primary bending, the natural vibration mode 2 indicates the natural frequency of twisting, and the natural vibration mode 3 indicates the natural frequency of the secondary bending. The rate of change (%) indicates the rate of change of each of the natural vibration modes 1 to 3, and the average value indicates the average value of the rates of change of these natural vibration modes 1 to 3. Here, if the absolute value of the average value of the rate of change is 12 or less, which is smaller than Comparative Examples 4 and 5 of the conventional shape, it is assumed that the state of suppressing abnormal noise at the time of new product is almost continued until the time of wear. When the average value of the rate was 12 or less as the permissible range, and when the average value of the rate of change exceeded 12, it was evaluated as out of the permissible range.

As is clear from Tables 1 and 2, the absolute value of the average value of the rate of change is the smallest at 3.13 in Example 1, the next smallest at 6.60 in Example 2, and 9. 23 was the next smallest, Example 4 was 11.57, the next smallest, and Examples 1 to 4 were within the permissible range of 12 or less. On the other hand, Comparative Example 1 is 12.01, Comparative Example 2 is 16.36, Comparative Example 3 is 20.83, Comparative Example 4 is 16.56, and Comparative Example 5 is 19.18. 5 is out of the permissible range exceeding 12.

Here, in Examples 1 to 4 having the arcuate groove 71, providing at least the arcuate groove 71 out of the arcuate groove 71, one straight groove 75 and the two straight grooves 76 is the natural frequency 1. It can be seen that it contributes to suppressing the rate of change and suppressing the rate of change of the natural frequency 2. However, regarding keeping the rate of change of the natural frequency 3 low, there is not much change even if at least one of one straight groove 75 and two straight grooves 76 is provided in addition to the arcuate groove 71. .. Therefore, in order to keep the rate of change of the natural frequency 3 low, it is considered that the optimization of the arcuate groove 71 is effective. That is, if the change in the natural vibration mode 3, that is, the change in the eigenvalue of the secondary bending can be suppressed low between the time of new product and the time of wear by optimizing the arcuate groove 71, the effect of suppressing abnormal noise at the time of new product is worn out. Considering that it can be continued until time, the size of the arcuate groove 71 that can suppress the change in the natural frequency of the secondary bending was verified by simulation using the finite element method.

The radius of the wall surface 72a on the large diameter side of the pair of groove portions 72 of the arcuate groove 71 is 65%, which is 0.325 times the total length L of the lining 52, and 60, which is 0.3 times the total length L of the lining 52. %, 70% which is 0.35 times the total length L of the lining 52, 55% which is 0.275 times the total length L of the lining 52, and 0.375 of the total length L of the lining 52. The case of 75%, which is doubled, was compared.

Then, for each of the new product (A) having a lining 52 thickness of 9.5 mm and the wear (B) having a lining 52 thickness of 4.75 mm, the natural frequency of the primary bending and the natural frequency of the secondary bending, respectively. The rate of change of the natural frequency of torsion was obtained by simulation. The results are shown in Table 3. Also in Table 3, the natural vibration mode 1 shows the eigenvalue of the primary bending, the natural vibration mode 2 shows the eigenvalue of the torsion, and the natural vibration mode 3 shows the eigenvalue of the secondary bending. Here, for the above reasons, the natural vibration mode 3, which is the natural frequency of the secondary bending, is compared, and if the rate of change of the natural vibration mode 3 is 4 or less, the natural frequency of the secondary bending when new is used. It was evaluated that the effect of suppressing the effect was obtained until the time of wear, and the rate of change was 4 or less as the permissible range, and the rate of change exceeding 4 was regarded as out of the permissible range.

As is clear from Table 3 and FIG. 8, the absolute value of the rate of change in the natural vibration mode 3 is 1.95, which is the smallest at 65%, and 3.04, which is the next smallest at 70%, and 60%. The case was 3.14, which was the next smallest, and these were 4 or less, which is the allowable range.

On the other hand, the absolute value of the rate of change in the natural vibration mode 3 was 6.16 in the case of 55% and 7.80 in the case of 75%, which were out of the permissible range exceeding 4. As a result, the radius of the arcuate groove 71 on the large diameter side is preferably 0.3 to 0.35 times the total length L of the lining 52 in the disk rotation direction, and 0.325 times the total length L of the lining 52. Most preferably.

Patent Document 1 describes that a groove structure formed in the lining suppresses a local temperature rise of the lining, and Patent Document 2 describes that a slit formed in the lining suppresses thermal deformation of the lining. Is described. By the way, in a new state, even if the brake caliper does not generate an abnormal noise, that is, a brake squeal, which occurs during braking, there is a problem that the brake squeal is generated as the mileage increases.

As one of the factors that cause deterioration squeal, it is considered that the vibration system of the brake caliper becomes unstable due to the change in the natural frequency of the brake pad due to the wear of the lining. Therefore, we focused on the natural frequency of the brake pad as one of the means to suppress the deterioration squeal, and suppressed the change of the natural frequency from the new state when the thickness of the lining is halved from the new state. The shape that can be used was examined based on the optimization calculation.

The brake pad 12 of the present embodiment is provided with the lining 52 provided with an arcuate groove 71 having a partial shape of an annulus centered at the center of the lining 52, so that the thickness of the lining 52 can be changed from a new state. Even if it is halved, it is possible to suppress the change in the natural frequency from the new state. Therefore, the brake pad 12 of the present embodiment and the disc brake 1 using the brake pad 12 can suppress the generation of abnormal noise, that is, the deterioration squeal, even when the thickness of the lining 52 is halved from the new state.

Further, in the brake pad 12 of the present embodiment, the radius of the arcuate groove 71 is set to 0.3 to 0.35 times the total length L of the lining 52 in the disc rotation direction, so that the thickness of the lining 52 is from a new state. It is possible to further suppress the change in the natural frequency from the new state when it is halved. Therefore, the brake pad 12 of the present embodiment and the disc brake 1 using the brake pad 12 can further suppress the deterioration squeal.

Further, the brake pad 12 of the present embodiment is a disc inside the disc radial direction and inside the arcuate groove 71 with respect to the straight line connecting the torque transmission portions 57 and 58 at one end and the torque transmission portions 57 and 58 at the other end. By forming one straight groove 75 extending in the radial direction, the contribution of the rigidity of the lining 52 to the natural vibration mode of the primary bending and twisting of the brake pad 12 can be reduced. The fluctuation of the frequency can be reduced more effectively. Therefore, the brake pad 12 of the present embodiment and the disc brake 1 using the brake pad 12 can further suppress the deterioration squeal.

Further, the brake pad 12 of the present embodiment is a disc on the outer side in the disc radial direction from the straight line connecting the torque transmission portions 57 and 58 at one end and the torque transmission portions 57 and 58 at the other end and inside the arcuate groove 71. By forming the two straight grooves 76 extending in the radial direction, the contribution of the rigidity of the lining 52 to the natural vibration mode of the primary bending and twisting of the brake pad 12 can be reduced. The fluctuation of the frequency can be reduced more effectively. Therefore, the brake pad 12 of the present embodiment and the disc brake 1 using the brake pad 12 can further suppress the deterioration squeal.

Further, in the brake pad 12 of the present embodiment, one straight groove 75 is formed near the center of the lining 52 in the disc rotation direction, so that the lining 52 particularly for the primary bending and torsional vibration modes of the brake pad 12. Since the contribution of the rigidity of the brake pad 12 can be reduced, the fluctuation of the natural frequency due to the wear of the brake pad 12 can be reduced more effectively. Therefore, the brake pad 12 of the present embodiment and the disc brake 1 using the brake pad 12 can further suppress the deterioration squeal.

A first aspect of the brake pad of the above embodiment is a brake pad having a back plate having torque transmitting portions for transmitting braking torque to support members at both ends and a lining attached to one surface side of the back plate. The lining is characterized by including an arcuate groove having a partial shape of an annulus having a center at the center of the lining. Therefore, the generation of abnormal noise can be suppressed.

A second aspect of the brake pad of the embodiment is characterized in that, in the first aspect, the arcuate groove has a radius of 0.3 to 0.35 times the total length of the lining in the disc rotation direction. do.

Further, in the first or second aspect, the third aspect of the brake pad of the embodiment is formed inside the disc radial direction with respect to the straight line connecting the torque transmission portions at both ends and inside the arc-shaped groove. One groove extending in the radial direction of the disk and two grooves extending in the radial direction of the disk formed outside the radial direction of the disk and inside the arc-shaped groove with respect to the straight line connecting the torque transmission portions at both ends. It is characterized by having a groove.

Further, in the fourth aspect of the brake pad of the embodiment, in the third aspect, a disk formed inside the arc-shaped groove on the inner side in the disc radial direction with respect to the straight line connecting the torque transmission portions at both ends. One groove extending in the radial direction is characterized in that it is formed near the center in the disc rotation direction of the lining.

Further, the disc brake of the embodiment includes a brake pad of any one of the first to fourth aspects. Therefore, the generation of abnormal noise can be suppressed.

1 Disc brake 10 Disc 11 Support member 12 Brake pad 51 Back plate 52 Lining 57 Torque transmission part 58 Torque transmission part 71 Arc-shaped groove 75 Straight groove (one groove)
76 Straight groove (2 grooves)

Claims (4)

A brake pad having a back plate having a torque transmitting portion for transmitting braking torque to a support member at both ends and a lining attached to one surface side of the back plate.
The lining is
Rutotomoni includes a deeply formed arcuate groove than half the thickness of the lining when new forms part shape of the ring which arranged around the central portion of the lining,
The torque transmission portions at both ends are inside the disk radial direction and inside the arc-shaped groove with respect to the straight line connecting the surfaces facing inward in the disk radial direction, and have the same depth as the arc-shaped groove from the tip surface of the lining when new. A groove formed by the sword and extending in the radial direction of the disc,
The torque transmission portions at both ends are outward in the disc radial direction from the straight line connecting the surfaces facing inward in the disc radial direction and inside the arc groove, and have the same depth as the arc groove from the tip surface of the lining when new. Two grooves extending in the radial direction of the disc formed by the
Brake pad, characterized in Rukoto provided with at least one of the. The brake pad according to claim 1, wherein the arc-shaped groove has a radius of 0.3 to 0.35 times the total length of the lining in the direction of disk rotation. The lining is
Inward from the arcuate groove a disc radially inward of the straight line connecting the onerous workers facing the disc radially inside of the torque transmitting portions of the opposite ends, identical to the arc-shaped grooves from the distal end surface of the lining at the time of a new With a single groove formed at depth and extending in the radial direction of the disc,
The brake pad according to claim 1 or 2, wherein the one groove is formed near the center of the lining in the disc rotation direction. A disc brake provided with the brake pad according to any one of claims 1 to 3.

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