JP2016008667A - Brake pad and brake pad manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake pad and a brake pad manufacturing method capable of suppressing a reduction of durability while suppressing noise.SOLUTION: A brake pad comprises a pair of pads 2, 3 opposite to each other across a disc rotor 4 in an axial direction of the disc rotor 4, the paired pads 2 and 3 include friction materials 22 and 32 and rear plates 21 and 31 supporting the friction materials 22 and 32, respectively, one of the paired pads 2, 3 includes a recessed portion 23 formed in a friction material-side surface of the rear plate or a surface thereof opposite to the friction material and a plate member 6 different in a material from the rear plate of the pad and fitted into the recessed portion 23, and an eigen frequency of one of the pads differs from an eigen frequency of the other pad.

Description

  The present invention relates to a brake pad and a method for manufacturing the brake pad.

  Conventionally, there are brake pads for disc brakes. For example, in Patent Document 1, a back plate is formed by laminating a plurality of flat plate-shaped plates having a predetermined plate thickness in the plate thickness direction, and integrally fixed to each other by an integrating means at a plurality of portions. Disc brake brake pad technology is disclosed.

JP-A-11-218164

  If the vibration characteristics of the two pads can be made different in a pair of pads facing each other with the disc rotor interposed therebetween, it is effective in suppressing noise generated during braking. However, if the vibration characteristics are adjusted by simply changing the material of the entire back plate of one of the pads, a dedicated pad is required separately, or the characteristics of the two types of pads are completely different. It is difficult to satisfy the required performance in terms of performance.

  An object of the present invention is to provide a brake pad and a method for manufacturing the brake pad that can achieve both reduction in durability and suppression of noise.

  The brake pad of the present invention includes a pair of pads facing each other across the disk rotor in the axial direction of the disk rotor, the pair of pads each having a friction material and a back plate that supports the friction material, One of the pair of pads is different from the material of the back plate having a concave portion formed on the friction material side surface of the back plate or the surface opposite to the friction material side. And a plate-like member fitted in the recess, wherein the one natural frequency and the other natural frequency are different.

  The said brake pad WHEREIN: It is preferable that the said recessed part and the said plate-shaped member are arrange | positioned in the center part of the said back plate which said one has.

  The brake pad of the present invention includes a pair of pads facing each other across the disk rotor in the axial direction of the disk rotor, the pair of pads each having a friction material and a back plate that supports the friction material, One of the pair of pads includes a through-hole penetrating the back plate in the axial direction and a plate-like member fitted into the through-hole, unlike the material of the back plate having the one material. And the one natural frequency is different from the other natural frequency.

  In the brake pad, it is preferable that the through hole and the plate-like member are arranged in a central portion of the back plate that the one has.

  The said brake pad WHEREIN: It is preferable that the surface on the opposite side to the said friction material side in the said plate-shaped member exists on the same surface as the surface on the opposite side to the said friction material side in the said back plate which said one has.

  In the brake pad, an elastic member is preferably interposed between the plate-like member and the back plate of the one.

  The brake pad manufacturing method according to the present invention includes a recess forming step of forming a substantially rectangular recess on the surface opposite to the friction material side of the back plate of the pad, and forming holes at the four corners of the recess. A hole forming step for removing an interference portion with a corner portion of a rectangular plate member, and a fitting step for fitting the plate member made of a material different from the back plate into the recess. Features.

  The brake pad according to the present invention includes a pair of pads facing each other with the disc rotor interposed therebetween in the axial direction of the disc rotor. Each of the pair of pads has a friction material and a back plate that supports the friction material, and one of the pair of pads is formed on the surface of the back plate on the friction material side or on the surface opposite to the friction material side. Unlike the material of the recess and the back plate that one of the materials has, a plate-like member fitted in the recess has one natural frequency different from the other natural frequency.

  According to the brake pad of the present invention, the natural frequency of one pad and the other pad can be made different by replacing a part of the back plate with a plate-like member, and noise generated during braking can be reduced. Is possible. Moreover, since it is the structure which replaces a part of back plate with a plate-shaped member, the existing pad can also be utilized and it is not necessary to prepare a pad separately. Furthermore, the change in pad characteristics is smaller than when the entire back plate is replaced, and it becomes easier to satisfy the required performance in terms of the durability of the pad.

FIG. 1 is a cross-sectional view of the disc brake according to the first embodiment. FIG. 2 is a plan view of the back plate of the first pad according to the first embodiment. FIG. 3 is a plan view of the first pad according to the first embodiment. FIG. 4 is an explanatory diagram of vibrations generated in the brake pad and the disc rotor. FIG. 5 is a cross-sectional view of a disc brake according to a first modification of the first embodiment. FIG. 6 is a plan view of the back plate of the first pad according to the first modification of the first embodiment. FIG. 7 is a plan view of a first pad according to a first modification of the first embodiment. FIG. 8 is a diagram illustrating the vibration characteristics of the pad according to the first modification of the first embodiment. FIG. 9 is a cross-sectional view of the first pad before the recess is formed. FIG. 10 is a plan view of the first pad before the recess is formed. FIG. 11 is a cross-sectional view for explaining the recess forming step. FIG. 12 is a plan view of the first pad after the recess is formed by the recess forming step. FIG. 13 is a cross-sectional view of the first pad in which the hole is formed by the hole forming process. FIG. 14 is a plan view of the first pad in which the hole is formed by the hole forming process. FIG. 15 is a plan view of a first pad according to a second modification of the first embodiment. FIG. 16 is a diagram illustrating the vibration characteristics of the pad according to the second modification of the first embodiment. FIG. 17 is a cross-sectional view of the first pad according to the second embodiment. FIG. 18 is a plan view of the first pad according to the second embodiment. FIG. 19 is a cross-sectional view of the first pad in which the through hole is formed. FIG. 20 is a plan view showing the back plate of the first pad in which the through hole is formed. FIG. 21 is a cross-sectional view of the first pad in which the hole is formed. FIG. 22 is a plan view showing the back plate of the first pad in which the hole is formed. FIG. 23 is a diagram illustrating a vibration characteristic of a pad according to a modification of each embodiment.

  Hereinafter, a brake pad and a brake pad manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[First Embodiment]
The first embodiment will be described with reference to FIGS. 1 to 4. The present embodiment relates to a brake pad. 1 is a cross-sectional view of a disc brake according to a first embodiment of the present invention, FIG. 2 is a plan view of a back plate of a first pad according to the first embodiment, and FIG. 3 is a first view according to the first embodiment. 4 is a plan view of one pad, and FIG. 4 is an explanatory view of vibrations generated in the brake pad and the disk rotor.

  As shown in FIG. 1, the disc brake 1 according to the embodiment includes a brake pad 10, a disc rotor 4, and a piston 5. The brake pad 10 includes a first pad 2 and a second pad 3. Unless otherwise specified in this specification, “axial direction” indicates the axial direction of the disk rotor 4, “circumferential direction” indicates a rotational direction with the central axis X of the disk rotor 4 as the rotation center, and “radial direction” "Denotes a radial direction orthogonal to the central axis X.

  The disk rotor 4 is connected to a vehicle tire and rotates integrally with the tire. The disk rotor 4 has an annular shape. The brake pad 10 has a pair of pads 2 and 3 that face each other with the disc rotor 4 interposed therebetween in the axial direction. The first pad 2 is disposed on one side in the axial direction with respect to the disk rotor 4, and the second pad 3 is disposed on the other side in the axial direction with respect to the disk rotor 4. That is, the second pad 3 is opposed to the first pad 2 with the disc rotor 4 interposed therebetween in the axial direction. One of the pair of pads 2 and 3 is disposed on the vehicle inner side in the vehicle width direction with respect to the disc rotor 4, and the other is disposed on the vehicle outer side in the vehicle width direction. The disc brake 1 sandwiches the disc rotor 4 between the pair of pads 2 and 3 and regulates the rotation of the disc rotor 4 by frictional contact with the disc rotor 4.

  The first pad 2 and the second pad 3 are supported by a caliper (not shown) and are relatively movable in the axial direction with respect to the disk rotor 4. The piston 5 is a pressing member that presses the first pad 2. When the piston 5 presses the first pad 2 toward the disk rotor 4 in the axial direction, the first pad 2 and the second pad 3 move toward the disk rotor 4 and sandwich the disk rotor 4. The piston 5 presses the first pad 2 against the disc rotor 4 with a pressing force corresponding to the supplied hydraulic pressure, and generates a braking force on the tire.

  The first pad 2 includes a friction material 22 and a back plate 21 that supports the friction material 22. The back plate 21 is a plate-like member and is arranged in parallel with the circumferential direction. FIG. 2 is a plan view of the back plate 21 as viewed in the direction A in FIG. The shape of the back plate 21 of this embodiment is a rectangle as shown in FIG. The back plate 21 is supported by calipers at both ends in the circumferential direction. The caliper regulates the movement of the back plate 21 in the circumferential direction and the radial direction and allows the back plate 21 to move in the axial direction. As shown in FIG. 1, the friction material 22 is connected to the surface of the back plate 21 on the disk rotor 4 side. The friction material 22 is fixed to the back plate 21 by adhesion, for example, and is supported by the back plate 21. The friction material 22 is a plate-like member, and its plate thickness is preferably constant.

  The second pad 3 includes a friction material 32 and a back plate 31 that supports the friction material 32. The back plate 31 is a plate-like member and is disposed in parallel with the circumferential direction. The back plate 31 is supported by calipers at both ends in the circumferential direction. The caliper supports the back plate 31 and restricts relative movement of the back plate 31 with respect to the caliper in each of the circumferential direction, the radial direction, and the axial direction. At the time of braking, the back plate 31 moves in the axial direction together with the caliper and presses the friction material 32 against the disc rotor 4. The friction material 32 is connected to the surface of the back plate 31 on the disk rotor 4 side. The friction material 32 is fixed to the back plate 31 by adhesion, for example, and is supported by the back plate 31. The friction material 32 is a plate-like member, and the plate thickness is preferably constant.

  Here, in the disc brake 1, vibration and noise during braking are a problem. During braking, two types of noise (squeal) are generated in the disk rotor 4. Among these, noise generated by bending vibration of the disc rotor 4 is referred to as noise due to out-of-plane vibration. Further, the noise due to the longitudinal vibration in which the inside and the density of the disk rotor 4 are generated is referred to as the noise due to the in-plane vibration. The in-plane vibration is vibration that propagates in the disk rotor 4 in a direction orthogonal to the axial direction, for example, in the circumferential direction.

  With reference to FIG. 4, the bending vibration of the brake pad and the in-plane vibration of the disc rotor will be described. A disc brake 101 shown in FIG. 4 has a disc rotor 105 and a pair of pads 102 and 102. The pair of pads 102 and 102 face each other in the axial direction with the disc rotor 105 interposed therebetween. The pad 102 has a back plate 103 and a friction material 104. The friction material 104 is connected to the disk rotor 105 side of the back plate 103. The disk rotor 105 rotates in the direction of the arrow Y1. When the pads 102 and 102 are pressed against the disc rotor 105, torque is input to the pad 102 as indicated by an arrow Y2. As a result, as shown by an arrow Y3, a force is applied to bend the central portion of the pad 102 away from the disc rotor 105.

  Due to the input of such an external force, the pad 102 deformed by the external force is restored to the original shape, etc., bending vibration that curves in the axial direction is generated in the pad 102. The bending vibration includes bending vibration in which both ends of the pad 102 in the circumferential direction are nodes, and the center in the circumferential direction is antinode, and bending vibration in which a plurality of antinodes exist between both ends of the pad 102 in the circumferential direction.

  In this specification, bending vibration in which i (i = 1, 2, 3,... N) antinodes exist between both ends of the pad 102 in the circumferential direction is referred to as i-th bending vibration. For example, vibration in which both ends in the circumferential direction of the pad 102 are nodes and one antinode exists at the center in the circumferential direction is referred to as “primary bending vibration” of the pad. Further, the bending vibration of the pad including the first bending vibration and the higher bending vibration is simply referred to as “bending vibration”.

  In-plane vibration is generated in the disk rotor 105 due to the bending vibration of the pad 102. If the natural frequency of the bending vibration is the natural frequency of the in-plane vibration of the disc rotor 105 or a frequency in the vicinity of the natural frequency, a large noise is generated due to resonance. Further, if the natural frequency of the bending vibration of the pair of pads 102 and 102 is the same frequency, the vibration level generated in the disk rotor 105 is increased.

  Here, in order to suppress the noise (noise) of the disk rotor 105 due to the bending vibration of the pad 102, it is effective to make one vibration characteristic of the pair of pads 102 and 102 different from the other vibration characteristic. For example, if the natural frequency of bending vibration of one pad 102 and the natural frequency of bending vibration of the other pad 102 can be shifted, generation of noise during braking can be suppressed or the level of noise can be reduced. It becomes possible. As means for adjusting the vibration characteristics of one pad 102, it is conceivable to change the thickness of the back plate 103 or the material of the entire back plate 103. However, simply changing the thickness or material of the back plate 103 changes the heat resistance, wear resistance, and strength performance, and often does not satisfy the required performance.

  There is also a measure to attenuate the vibration by a shim connected to the back plate 103. However, in the case of attenuation due to shims, there is a problem that the effect is likely to vary depending on the outside air environment (heat, moisture).

  In the brake pad 10 of the present embodiment, the first pad 2 that is one of the first pad 2 and the second pad 3 has a recess 23 and a plate-like member 6. In the present embodiment, the first pad 2 is different from the second pad 3 in that a recess 23 is provided and a plate-like member 6 is fitted in the recess 23. That is, the back plate 21 of the first pad 2 and the back plate 31 of the second pad 3 are made of the same material and have the same shape except for the presence or absence of the recess 23. The friction material 22 of the first pad 2 and the friction material 32 of the second pad 3 are made of the same material and have the same shape. Accordingly, the vibration characteristics of the first pad 2 are the same as those of the second pad 3 if the back plate 21 is not provided with the recess 23 and the plate-like member 6 is not fitted.

  In the following description, the surface on the disk rotor 4 side of the back plate 21 is referred to as a front surface 24, and the surface of the back plate 21 opposite to the disk rotor 4 side is referred to as a back surface 25. The recess 23 is formed on the back surface 25 of the back plate 21 of the first pad 2. The recess 23 is substantially rectangular as shown in FIG. The concave portion 23 is formed, for example, by machining with a lathe or the like on the first pad 2 after the friction material 22 is fixed. The recess 23 is provided between the end surface 21a on one side in the circumferential direction of the back plate 21 and the end surface 21b on the other side in the circumferential direction. Further, the recess 23 is provided between the end face 21c on one side in the radial direction and the end face 21d on the other side in the radial direction in the back plate 21. The installation position and installation range of the recess 23 in the circumferential direction, and the installation position and installation range of the recess 23 in the radial direction are appropriately determined from the viewpoint of ensuring strength, for example.

  As shown in FIG. 1, the bottom surface 23 e of the recess 23 is a plane parallel to the back surface 25. The shape of the plate-like member 6 is a flat plate shape. The shape of the plate-like member 6 in plan view is, for example, a rectangle as shown in FIG. The plate-like member 6 is fitted in the recess 23. The plate-like member 6 is press-fitted into the recess 23, and the four sides of the plate-like member 6 are held by the inner wall surfaces 23a, 23b, 23c, and 23d as shown in FIG. The plate-like member 6 is sandwiched between the inner wall surface 23a and the inner wall surface 23b from both sides in the circumferential direction, and relative movement in the circumferential direction and the radial direction with respect to the back plate 21 is restricted. Further, the plate-like member 6 is sandwiched between the inner wall surface 23c and the inner wall surface 23d from both sides in the radial direction, and relative movement in the circumferential direction and the radial direction with respect to the back plate 21 is restricted. Further, when the plate-like member 6 tries to move relative to the back plate 21 in the direction toward the disk rotor 4, the relative movement is restricted by the bottom surface 23 e of the recess 23. That is, when the plate-like member 6 is fitted into the recess 23, it is easy to restrict the relative movement of the plate-like member 6 in the circumferential direction, the radial direction, and the axial direction with respect to the back plate 21.

  The plate-like member 6 is preferably fitted into the recess 23 so as not to protrude outside the recess 23. For example, it is preferable that the back surface 6a (see FIG. 1) of the plate member 6 and the back surface 25 of the back plate 21 are on the same plane in a state where the plate member 6 is fitted in the recess 23. If it does in this way, the back surface 25 and the back surface 6a will contact | abut with respect to the press surface 5a of the piston 5, respectively. Therefore, uneven wear of the friction material 22 or the friction material 22 with respect to the disk rotor 4 is suppressed.

  In the disc brake 1 of the present embodiment, the material of the plate-like member 6 is different from the material of the back plate 21, and the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 are different. Here, when the material of the back plate 21 is “material 1” and the material of the plate-like member 6 is “material 2”, the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 are different. Thus, it is desirable that the natural frequency of the plate-like member 6 be different between the case where the plate-like member 6 having the same shape is formed of the material 1 and the case where it is formed of the material 2. In other words, the natural frequency of the first pad 2 in which the concave portion 23 is replaced by the plate-like member 6 is different from the natural frequency of the first pad 2 when the concave portion 23 is not formed on the back plate 21. The material of the plate member 6 is preferably selected.

  Since the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 are different, noise during braking can be suppressed. For example, when the first pad 2 is not provided with the recess 23 or the plate-like member 6 and the natural frequency F1 of the first pad 2 is equal to the natural frequency F2 of the second pad 3, the natural frequency F2 is applied during braking. The vibration level of (= F1) increases. When the natural frequency F2 is a frequency close to the natural frequency of the in-plane vibration of the disk rotor 4, noise during braking increases. On the other hand, if the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 are different, at least one of the natural frequencies F1 and F2 is separated from the natural frequency of the disc rotor 4. There is a high possibility that the frequency will be high. Therefore, according to the brake pad 10 of the present embodiment, noise during braking can be suppressed.

  The brake pad 10 of the present embodiment is configured such that the natural frequency of one pad (first pad 2) and the other pad (second pad 3) is made different by replacing a part of the back plate 21 with the plate-like member 6. It is possible to reduce noise generated during braking. Moreover, since it is the structure which replaces a part of back plate 21 with the plate-shaped member 6, the existing pad can also be utilized and it is not necessary to prepare a pad separately. Furthermore, the change in the pad characteristics is less than when the entire back plate 21 is replaced, and it becomes easy to satisfy the required performance in terms of the durability of the pad.

  The brake pad 10 of the present embodiment can reduce vibration regardless of the vibration characteristics of the disk rotor 4 combined with the disk rotor 4. In the brake pad 10 of the present embodiment, the vibration characteristics of the two pads 2 and 3 are different, and the natural frequencies F1 and F2 are different, so that noise during braking is reduced as compared with the case where the natural frequencies F1 and F2 are equal. It's easy to do. For example, even if one of the natural frequencies F 1 and F 2 overlaps with the natural frequency F 0 of the disk rotor 4, the other can be a frequency away from the natural frequency F 0 of the disk rotor 4. Therefore, according to the brake pad 10 of the present embodiment, an effect of suppressing noise during braking can be expected regardless of the vibration characteristics of the disk rotor 4 to be combined.

  The first pad 2 of the present embodiment can change the vibration characteristics of the first pad 2 without changing the material and the outer shape of the back plate 21 serving as a base. That is, the natural frequency can be adjusted by fitting the plate-like member 6 into the recess 23 while utilizing the durability of the back plate 21 serving as the base. Therefore, according to the brake pad 10 of the present embodiment, it is possible to achieve both the reduction in durability and the suppression of noise.

[First Modification of First Embodiment]
A first modification of the first embodiment will be described. 5 is a cross-sectional view of a disc brake according to a first modification of the first embodiment, FIG. 6 is a plan view of a back plate of the first pad according to the first modification of the first embodiment, and FIG. 8 is a plan view of a first pad according to a first modification of the first embodiment, FIG. 8 is a diagram showing vibration characteristics of the pad according to the first modification of the first embodiment, and FIG. 9 is formed with a recess. FIG. 10 is a plan view of the first pad before the concave portion is formed, FIG. 11 is a cross-sectional view illustrating the concave portion forming step, and FIG. 12 is a sectional view of the first pad before the concave portion is formed. FIG. 13 is a cross-sectional view of the first pad in which the hole is formed by the hole forming process, and FIG. 14 is a first view in which the hole is formed by the hole forming process. It is a top view of one pad.

  In the brake pad 10 according to the first modification of the first embodiment, the vibration characteristic of the brake pad 10 is adjusted by adjusting the value P obtained by dividing the Young's modulus E by the specific gravity γ as means for changing the natural frequency of the material. To do. A hole 23 h is provided at the corner of the recess 23.

  As shown in FIG. 6, holes 23 h are provided at the four corners of the recess 23. Thereby, interference with the corner | angular part of the plate-shaped member 6 when fitting the plate-shaped member 6 in the recessed part 23 and the corner part of the recessed part 23 is suppressed.

The adjustment of the natural frequency in the brake pad 10 of this modification will be described. In the first pad 2 of this modification, the value P1 (= E1 / γ1) obtained by dividing the Young's modulus E1 of the plate-like member 6 by the specific gravity γ1 of the plate-like member 6 is the Young's modulus of the back plate 21 of the first pad 2. This is different from the value P2 (= E2 / γ2) obtained by dividing E2 by the specific gravity γ2 of the back plate 21. That is, the relationship of the following formula (1) or formula (2) is established.
P1 <P2 (1)
P1> P2 (2)

  The Young's modulus E and specific gravity γ of the member influence the natural frequency of the bending vibration of the member. A member having a large value P obtained by dividing Young's modulus E by specific gravity γ has a higher natural frequency than a member having a small value P obtained by dividing Young's modulus E by specific gravity γ. Therefore, the vibration characteristic (eigenvalue) of the first pad 2 can be changed by fitting the plate member 6 satisfying the relationship of the above formulas (1) and (2) into the back plate 21.

  That is, in the brake pad 10 of this modification, the value P1 obtained by dividing the Young's modulus E1 of the plate-like member 6 by the specific gravity γ1 of the plate-like member 6 is the Young's modulus E2 of the back plate 21 of the first pad 2. By differing from the value P2 divided by the specific gravity γ2 of the plate 21, the natural frequency F1 of the first pad 2 is different from the natural frequency F2 of the other pad (second pad 3).

  In the brake pad 10 of this modification, the plate-like member 6 that satisfies the relationship of the above formula (1) is fitted into the back plate 21 of the first pad 2. Thereby, as will be described with reference to FIG. 8, the vibration characteristic of the first pad 2 is shifted to the low frequency side. In FIG. 8, the horizontal axis represents frequency [Hz], and the vertical axis represents vibration gain [dB]. FIG. 8 shows a vibration characteristic curve G1 of the first pad 2 and a vibration characteristic curve G2 of the second pad 3. The vibration characteristic curve G2 of the second pad 3 is also the vibration characteristic curve of the first pad 2 before the recess 23 is formed in the back plate 21.

  As shown in FIG. 8, the natural frequency F1 of the primary bending vibration of the first pad 2 is lower than the natural frequency F2 of the primary bending vibration of the second pad 3. Further, the gain peak value G1max of the first pad 2 is smaller than the gain peak value G2max of the second pad 3.

  Thus, in the brake pad 10 according to this modification, the plate-like member 6 having a smaller ratio P between the Young's modulus E and the specific gravity γ than the back plate 21 is fitted in the recess 23. As a result, the natural frequency F1 of the first pad 2 is lower than the natural frequency F2 of the second pad 3. The brake pad 10 having such a combination is advantageous when the natural frequency F0 of the in-plane vibration of the disk rotor 4 is higher than the natural frequency F2 of the second pad 3, as shown in FIG. Conceivable. When the natural frequency F2 of the second pad 3 is lower than the natural frequency F0 of the disk rotor 4, if the natural frequency F1 of the first pad 2 is a lower frequency, the natural vibration of the first pad 2 It is considered that noise due to vibration of the disk rotor 4 during braking can be more effectively suppressed than when the number F1 is equal to the natural frequency F2 of the second pad 3.

  As described above, the brake pad 10 in which the natural frequency F1 of the first pad 2 is shifted to the low frequency side is combined with the disc rotor 4 having the natural frequency F0 higher than the natural frequency F2 of the second pad 3. In this case, the first pad 2 is so designed that the vibration of the disc rotor 4 generated when the disc rotor 4 is braked by the pair of pads 2 and 3 is smaller than when the natural frequency F1 is equal to the natural frequency F2. It can be said that the natural frequency F <b> 1 is different from the natural frequency F <b> 2 of the second pad 3.

  Further, the brake pad 10 may be combined with the disk rotor 4 having various vibration characteristics. The natural frequency F0 of the in-plane vibration of the disk rotor 4 has a correlation with the diameter of the disk rotor 4. In general, the natural frequency F0 of the disk rotor 4 having a large diameter is lower than the natural frequency F0 of the disk rotor 4 having a small diameter. Therefore, depending on the diameter of the disc rotor 4, it is possible to assume a range of frequencies that are not preferable to be combined with the disc rotor 4 having the diameter as the natural frequency of the brake pad 10. When the natural frequency F2 of the second pad 3 is on the low frequency side with respect to the unfavorable frequency range, if the natural frequency F1 of the first pad 2 is a lower frequency, the disk rotor 4 having the diameter. It is considered that the noise reduction effect is enhanced when combined with.

  When there is a maximum diameter of the disc rotor 4 that can be used according to the vehicle type, at least the first of the pair of pads 2 and 3 with respect to the natural frequency (range) assumed in the maximum-diameter disc rotor 4. The natural frequency F1 of the pad 2 may be set to a low frequency.

  In the first pad 2 of this modification, the value P1 obtained by dividing the Young's modulus E1 of the plate-like member 6 by the specific gravity γ1 of the plate-like member 6 divides the Young's modulus E2 of the back plate 21 by the specific gravity γ2 of the back plate 21. By being smaller than the value P2, the peak value G1max of the gain of the first pad 2 is lower than when the recess 23 and the plate-like member 6 are not provided. Therefore, the vibration level of the first pad 2 during braking is reduced, and noise is suppressed.

  Moreover, in the brake pad 10 of this modification, not only the natural frequency F1 of the primary bending vibration of the first pad 2 and the natural frequency F2 of the primary bending vibration of the second pad 3 are different, but other orders. As for the natural frequency of the bending vibration, it can be expected that the first pad 2 and the second pad 3 have different frequencies. That is, the first pad 2 and the second pad 3 vibrate at the same order at the natural frequency F0 of the disk rotor 4, and the vibration is suppressed from being synchronized. Therefore, the vibration level of the in-plane vibration of the disk rotor 4 is reduced, and noise during braking is suppressed. Examples of the material of the back plate 21 and the plate-like member 6 that satisfy the relationship of the above formula (1) include carbon steel (as an example, S45C) as the material of the back plate 21 and brass as the material of the plate-like member 6. It is done.

  In addition, when the plate-like member 6 that satisfies the relationship of the above formula (2) is fitted into the back plate 21 of the first pad 2, the vibration characteristics of the first pad 2 can be shifted to the high frequency side. In this case, the natural frequency F1 of the primary bending vibration of the first pad 2 is higher than the natural frequency F2 of the primary bending vibration of the second pad 3. The brake pad 10 having such a combination is considered advantageous when the natural frequency F0 of the in-plane vibration of the disk rotor 4 is lower than the natural frequency F2 of the second pad 3. When the natural frequency F2 of the second pad 3 is higher than the natural frequency F0 of the disc rotor 4, if the natural frequency F1 of the first pad 2 is a higher frequency, the noise during braking is effective. It is thought that it can be suppressed.

  Thus, the brake pad 10 in which the natural frequency F1 of the first pad 2 is shifted to the high frequency side is combined with the disc rotor 4 having the natural frequency F0 lower than the natural frequency F2 of the second pad 3. In this case, the first pad 2 is so designed that the vibration of the disc rotor 4 generated when the disc rotor 4 is braked by the pair of pads 2 and 3 is smaller than when the natural frequency F1 is equal to the natural frequency F2. It can be said that the natural frequency F <b> 1 is different from the natural frequency F <b> 2 of the second pad 3.

  Assuming a range of frequencies that are not desirable to be combined with a disc rotor 4 of a certain diameter, when the natural frequency F2 of the second pad 3 is on the high frequency side with respect to the range of unfavorable frequencies, If the natural frequency F1 of the first pad 2 is a higher frequency, it is considered that the noise reduction effect is enhanced when combined with the disk rotor 4 having the diameter.

  When there is a minimum diameter of the disk rotor 4 that can be used depending on the vehicle type, at least the first of the pair of pads 2 and 3 with respect to the natural frequency (range) assumed in the minimum-diameter disk rotor 4. The natural frequency F1 of the pad 2 may be set to a high frequency.

  Examples of the material of the back plate 21 and the plate-like member 6 that satisfy the relationship of the above formula (2) include carbon steel (as an example, S45C) as the material of the back plate 21, and carbon fiber (as an example of the material of the plate-like member 6). An example is carbon fiber reinforced plastic).

  As described above, in the brake pad 10 of this modification, the natural frequency F1 of the first pad 2 is lower than the natural frequency F2 of the second pad 3 in accordance with the vibration characteristics of the disk rotor 4 to be combined. By shifting to the frequency side or the high frequency side, noise during braking can be effectively suppressed.

  In the first pad 2 of the present modification, the concave portion 23 and the plate-like member 6 are disposed in the central portion of the back plate 21 in the circumferential direction. As shown in FIGS. 5 and 6, the distance L1 from the inner wall surface 23a on one side in the circumferential direction in the recess 23 to the end surface 21a on one side in the circumferential direction in the back plate 21 and the other side in the circumferential direction in the recess 23 The distance L1 from the inner wall surface 23b to the other end surface 21b in the circumferential direction of the back plate 21 is equal. As a result, it is possible to greatly change the natural frequency of the primary bending vibration. In the primary bending vibration, the center of the back plate 21 in the circumferential direction becomes an antinode, and the first pad 2 undergoes bending vibration. Therefore, the natural frequency of the primary bending vibration in the first pad 2 is changed by changing the ratio P between the Young's modulus E and the specific gravity γ of the first pad 2 by the plate-like member 6 at the center of the back plate 21 in the circumferential direction. Can be changed greatly.

  Further, among the natural frequencies of each order of the bending vibration in the pad, the natural frequency of the primary bending vibration is often a frequency close to the natural frequency of the in-plane vibration of the disk rotor 4. Therefore, the natural frequency of the primary bending vibration of the first pad 2 is adjusted by arranging the concave portion 23 and the plate-like member 6 at the center of the back plate 21 in the circumferential direction, and the natural frequency of the disc rotor 4 is adjusted. It is easy to avoid overlapping with the area.

  By providing the recess 23 and the plate-like member 6, not only the natural frequency F1 of the primary bending vibration of the first pad 2 but also the natural frequency of the secondary or higher bending vibration is changed. It may not be preferable from the viewpoint. For example, it is not preferable that the natural frequency of the second or higher order bending vibration decreases and approaches the natural frequency F0 of the disk rotor 4. From the viewpoint of changing the natural frequency F1 of the primary bending vibration and suppressing the influence of the secondary or higher bending vibration on the natural frequency, the circumferential length of the concave portion 23 and the plate-like member 6 has a certain upper limit. It is considered preferable to provide For example, in the secondary bending vibration, both ends and the center of the back plate 21 in the circumferential direction are nodes, and the position of the antinode is an intermediate position between adjacent nodes. Therefore, the distance L1 (see FIG. 6) from the inner wall surface 23a of the recess 23 to the end surface 21a of the back plate 21 and the distance L1 from the inner wall surface 23b to the end surface 21b of the back plate 21 are the total length in the circumferential direction of the back plate 21. On the other hand, it is preferably larger than 1/4. In other words, the overall length L3 of the recess 23 in the circumferential direction is preferably 1/2 or less with respect to the overall length of the back plate 21.

  In the third-order bending vibration, the positions at which the entire length of the back plate 21 in the circumferential direction is divided into three equal parts. In consideration of the influence of the tertiary bending vibration on the natural frequency, the distance L1 and the total length L3 of the recess 23 may be, for example, about 1/3 of the total length of the back plate 21 in the circumferential direction. Further, the overall length L3 of the recess 23 may be less than 1/3 of the overall length of the back plate 21 in the circumferential direction, and the distance L1 may be greater than 1/3 of the overall length of the back plate 21.

  Further, in the brake pad 10 of the present modified example, as shown in FIG. 6, a distance L2 from the inner wall surface 23c on one side in the radial direction in the recess 23 to the end surface 21c on the one side in the radial direction in the back plate 21, 23 is equal to the distance L2 from the inner wall surface 23d on the other radial side to the end surface 21d on the other radial side of the back plate 21. The distance L2 is, for example, ¼ of the total length of the back plate 21 in the radial direction.

  Here, the manufacturing method of the 1st pad 2 which concerns on this modification is demonstrated. The manufacturing method of the 1st pad 2 is comprised including the recessed part formation process, the hole formation process, and the fitting process.

(Recess formation process)
The recessed portion forming step is a step of forming a substantially rectangular recessed portion 23 on the back surface 25 which is the surface opposite to the friction material 22 side in the back plate 21. In this modification, a case where the recess 23 is formed on the back plate 21 to which the friction material 22 has already been fixed will be described. FIG. 9 shows a cross section of the first pad 2 before the recess 23 is formed. FIG. 10 shows the back surface 25 of the back plate 21 before the recess 23 is formed. The back plate 21 before the recess 23 is formed has a uniform plate thickness.

  FIG. 11 shows a cross section of the first pad 2 during formation of the recess 23. FIG. 12 also shows the back surface 25 of the back plate 21 after the recess 23 is formed. As shown in FIG. 11, the back plate 21 is shaved from the back surface 25 side by the cutting tool 7 of a processing machine such as a lathe to form a recess 23. Here, in the case of machining by a lathe or the like, curved surface portions 23f are formed at the four corners of the recess 23 as shown in FIG. That is, the planar shape of the recess 23 is a shape in which the four corners of the rectangle are rounded in a chamfered shape. If the curved surface portion 23f remains, even if the plate-like member 6 is to be fitted into the recess 23, the corner portion of the plate-like member 6 interferes with the interference portion 23g. The interference portion 23g is an area surrounded by an extended line extending the inner wall surfaces 23a and 23b in the radial direction, an extended line extending the inner wall surfaces 23c and 23d in the circumferential direction, and the curved surface portion 23f.

(Hole formation process)
The hole forming step is executed between a recess forming step and a fitting step described later. The hole forming process is a process of forming holes at the four corners of the recess 23 and removing the interference portions 23 g with the corners of the plate-like member 6. By performing the hole forming step, the contact area of the fitting portion between the plate-like member 6 and the back plate 21 is stabilized. A hole 23h having a circular cross section is formed on the back plate 21 from the back surface 25 side by a processing machine such as a lathe. As shown in FIG. 14, the hole 23h can remove at least the interference portion 23g. That is, the hole 23h includes an interference portion 23g in the plan view shown in FIG. The hole 23h is formed so as not to penetrate the back plate 21. That is, the hole 23h after the drilling has a bottomed shape. The depth of the hole 23 h is preferably equal to or greater than the plate thickness of the plate-like member 6.

(Fitting process)
The fitting step is a step of fitting the plate member 6 having a rectangular planar shape into the recess 23. The plate-like member 6 is made of a material different from a value P2 obtained by dividing the Young's modulus E1 by the specific gravity γ1 and a value P2 obtained by dividing the Young's modulus E2 of the backplate 21 by the specific gravity γ2 of the backplate 21. The plate member 6 is fitted into the recess 23 by press fitting or the like. By forming the hole portion 23h, the corner portion of the plate-like member 6 is prevented from interfering with the interference portions 23g at the four corners of the recess portion 23. In the fitting step, the fitting is preferably performed so that the back surface 6 a (the surface opposite to the friction material 22 side) of the plate-like member 6 is on the same surface as the back surface 25 of the back plate 21. Note that the surface 6 b (surface on the friction material 22 side) of the plate-like member 6 may be separated from the bottom surface 23 e of the recess 23 in a state of being fitted in the recess 23.

  According to the manufacturing method of the brake pad of this modification, it is possible to manufacture the brake pad 10 that can achieve both reduction in durability and suppression of noise.

[Second Modification of First Embodiment]
A second modification of the first embodiment will be described. FIG. 15 is a plan view of a first pad according to a second modification of the first embodiment, and FIG. 16 is a diagram showing vibration characteristics of the pad. The first pad 2 according to the second modification of the first embodiment differs from the first pad 2 of the first embodiment in that an elastic member 8 is interposed between the back plate 21 and the plate-like member 6. It is a point.

  The elastic member 8 is, for example, a resin such as rubber or an adhesive. The elastic member 8 is sandwiched between the inner wall surfaces 23 a, 23 b, 23 c, 23 d of the recess 23 and the side surfaces of the plate-like member 6. When the plate-like member 6 is fitted into the recess 23 in the fitting step, the elastic member 8 is adhered or applied to each inner wall surface 23a, 23b, 23c, 23d of the recess 23, and the plate-like member 6 is inserted into the recess 23. Or the elastic member 8 may be attached or applied to each side surface of the plate-like member 6 so that the plate-like member 6 is fitted into the recess 23.

  Since the elastic member 8 is interposed between the back plate 21 and the plate-like member 6, the plate-like member 6 is elastically supported by the back plate 21 via the elastic member 8. Therefore, it is suppressed that the vibration of the back plate 21 and the vibration of the plate-like member 6 are synchronized. In the first pad 2 of this modification, the elastic member 8 and the plate-like member 6 can function as a dynamic damper that absorbs vibration of the back plate 21. For example, it is preferable that the mass or the like of the plate-like member 6 is adjusted so as to effectively exhibit a vibration absorbing effect at the frequency of the primary bending vibration of the back plate 21. On the other hand, the elastic member 8 and the back plate 21 function as a dynamic damper against bending vibration of the plate-like member 6. For example, it is preferable that the mass or the like of the back plate 21 is adjusted so as to effectively exhibit a vibration absorbing effect at the frequency of the primary bending vibration of the plate-like member 6.

  As will be described with reference to FIG. 16, in the vibration characteristic curve G3 of the first pad 2 of the present modification, vibration gain peaks are dispersed. In FIG. 16, a solid line G4 is a vibration characteristic curve of the first pad 2 when the elastic member 8 is not interposed between the plate-like member 6 and the back plate 21 of the first pad 2, for example, in the first embodiment. 3 is a vibration characteristic curve of the first pad 2 in the form (hereinafter referred to as “vibration characteristic curve G4 of a comparative example”). A broken line G3 indicates a vibration characteristic curve of the first pad 2 of the present modification. In the first pad 2 according to the present modification, the elastic member 8 is interposed between the plate-like member 6 and the back plate 21, so that the gain peaks are dispersed. In the vibration characteristic curve G4 of the comparative example, a peak value G4max of the vibration gain exists at the frequency F5. In the vibration characteristic curve G3 of the first pad 2, the peaks are dispersed at the frequency F3 and the frequency F4. The peak value G3max of the frequency F3 is larger than the peak value of the frequency F4 and smaller than the peak value G4max of the vibration characteristic curve G4 of the comparative example.

  For example, when the plate-like member 6 that satisfies the relationship of the above formula (1) is used in the first pad 2, the natural frequency on the relatively low frequency side of the two natural frequencies F3 and F4 where the peak values appear is relatively low. The frequency F3 corresponds to the natural frequency of the primary bending vibration of the plate-like member 6, and the natural frequency F4 on the relatively high frequency side corresponds to the natural frequency of the primary bending vibration of the back plate 21. Conceivable. As the vibration gain peaks are dispersed, the gain peak value G3max of the first pad 2 becomes smaller than the gain peak value G4max of the vibration characteristic curve G4 of the comparative example.

[Third Modification of First Embodiment]
A third modification of the first embodiment will be described. In the said 1st Embodiment, although the recessed part 23 was formed in the back surface 25 side of the backplate 21, it replaces with this and the recessed part 23 may be formed in the surface 24. FIG. In this case, the recess 23 is formed in the back plate 21, and the friction material 22 may be fixed to the back plate 21 after the plate-like member 6 is fitted in the recess 23. It is preferable that the surface 6b of the plate-like member 6 fitted in the recess 23 and the surface 24 of the back plate 21 are on the same plane.

  In the manufacture of the first pad 2 of the first embodiment, the friction material 22 may be fixed to the back plate 21 after the recess 23 is formed in the back plate 21. For example, the friction material 22 may be fixed to the back plate 21 after the plate-like member 6 is fitted in the recess 23.

  The planar shape of the recessed part 23 is not limited to what was illustrated. The planar shape of the concave portion 23 of each of the first embodiment and each modification of the first embodiment is a rectangle whose circumferential length is longer than the radial length. May be shorter than the length in the radial direction. Further, the planar shape of the recess 23 may be a square. Further, the planar shape of the recess 23 may be, for example, a polygonal shape other than a rectangle or a circle.

[Second Embodiment]
The second embodiment will be described with reference to FIGS. 17 to 22. In the second embodiment, components having the same functions as those described in the first embodiment are given the same reference numerals, and duplicate descriptions are omitted. 17 is a cross-sectional view of the first pad according to the second embodiment, FIG. 18 is a plan view of the first pad according to the second embodiment, and FIG. 19 is a cross-sectional view of the first pad in which a through hole is formed. 20 is a plan view showing the back plate of the first pad in which the through hole is formed, FIG. 21 is a sectional view of the first pad in which the hole is formed, and FIG. 22 is the first view in which the hole is formed. It is a top view which shows the back board of one pad. The first pad 2 of the second embodiment is different from the first pad 2 of the first embodiment in that a through hole 26 is provided in the back plate 21 instead of the recess 23.

  As shown in FIG. 17, the first pad 2 includes a through hole 26 that penetrates the back plate 21 in the axial direction, and a plate-like member 6 that is fitted in the through hole 26. It is preferable that the through hole 26 and the plate-like member 6 are disposed in the central portion of the back plate 21 in the circumferential direction. The value P1 obtained by dividing the Young's modulus E1 of the plate-like member 6 by the specific gravity γ1 of the plate-like member 6 is different from the value P2 obtained by dividing the Young's modulus E2 of the back plate 21 of the first pad 2 by the specific gravity γ2 of the back plate 21. The first pad 2 of the present embodiment is paired with the second pad 3 and used as the brake pad 10 in the same manner as the first pad 2 of the first embodiment.

  Accordingly, in the first pad 2 of the present embodiment, the natural frequency F1 of the primary bending vibration is equal to that of the first bending vibration of the second pad 3 as in the first pad 2 of the first embodiment. It becomes a value different from the frequency F2. The disc generated when the disc rotor 4 is braked by the pair of pads 2 and 3 than when the two natural frequencies F1 and F2 are equal because the natural frequencies F1 and F2 of the pair of pads 2 and 3 are different. It is possible to reduce the vibration of the rotor 4. When the natural frequency F0 of the in-plane vibration of the disc rotor 4 is higher than the natural frequency F2 of the second pad 3, the natural frequency F1 of the first pad 2 is lower than the natural frequency F2 of the second pad 3. It is preferable. When the natural frequency F0 of the in-plane vibration of the disk rotor 4 is lower than the natural frequency F2 of the second pad 3, the natural frequency F1 of the first pad 2 is greater than the natural frequency F2 of the second pad 3. Is preferably high.

  According to the brake pad 10 of the present embodiment, a pair of pads 2 and 3 are formed in the same manner as the brake pad 10 of the first embodiment, as compared with the case where one natural frequency F1 is equal to the other natural frequency F2. Thus, it is possible to make one natural frequency F1 of the pair of pads 2 and 3 different from the other natural frequency F2 so that vibration generated when the disk rotor 4 is braked is reduced. In the brake pad 10 of the present embodiment, the plate-like member 6 is fitted into the through hole 26, so that the relative movement in the circumferential direction and the radial direction of the plate-like member 6 with respect to the back plate 21 can be easily regulated. Further, when the through hole 26 is formed in the back plate 21, unlike the case where the concave portion 23 is formed, it is not necessary to stop at a mid-depth position when cutting the back plate 21, and the processing is easy.

  A method for manufacturing the first pad 2 of this embodiment will be described. The manufacturing method of the 1st pad 2 of this embodiment is comprised including the through-hole formation process, the hole formation process, and the fitting process.

(Through hole forming process)
The through-hole forming step is a step of forming in the back plate 21 a substantially rectangular through hole 26 that penetrates the back plate 21 in the axial direction. The through hole 26 is formed by a processing machine such as a lathe with respect to the back plate 21 (see FIGS. 9 and 10) before the through hole 26 is formed. 19 and 20 show the back plate 21 in which the through holes 26 are formed.

  As shown in FIG. 20, curved surface portions 26 f exist at the four corners of the through hole 26. If the plate-like member 6 is to be fitted into the through hole 26 in this state, the corner of the plate-like member 6 interferes with the interference portion 26g.

(Hole formation process)
The hole forming step is performed between the through hole forming step and the fitting step, and is a step of forming the hole portions 26h at the four corners of the through hole 26 and removing the interference portions 26g with the corner portions of the plate-like member 6. is there. As shown in FIG. 22, the hole 26h includes an interference portion 26g in plan view. The interference part 26g is removed by forming the hole 26h by the processing machine. The depth of the hole 26h is preferably deeper than the depth corresponding to the plate thickness of the plate member 6 to be fitted.

(Fitting process)
The fitting step is a step of fitting the plate member 6 having a rectangular planar shape into the through hole 26. The plate-like member 6 is made of a material different from a value P2 obtained by dividing the Young's modulus E1 by the specific gravity γ1 and a value P2 obtained by dividing the Young's modulus E2 of the backplate 21 by the specific gravity γ2 of the backplate 21. The plate member 6 is fitted into the through hole 26 by press fitting or the like. By removing the interference portion 26g in the hole forming step, the corner portions of the plate-like member 6 are prevented from interfering with the interference portions 26g at the four corners of the through hole 26. In the fitting step, the fitting is preferably performed so that the back surface 6 a of the plate-like member 6 is on the same plane as the back surface 25 of the back plate 21.

  The plate-like member 6 fitted into the through-hole 26 in the fitting step is held on the side surfaces by the inner wall surfaces 26a, 26b, 26c, 26d of the through-hole 26, and is relative to the back plate 21, as shown in FIG. Fixed immovable.

[Modification of Second Embodiment]
A modification of the second embodiment will be described. In the first pad 2 of the second embodiment, an elastic member 8 may be interposed between the plate member 6 and the back plate 21. For example, the elastic member 8 may be interposed between each inner wall surface 26 a, 26 b, 26 c, 26 d of the through hole 26 and each side surface of the plate-like member 6. Moreover, in the manufacturing method of the 1st pad 2 of the said 2nd Embodiment, the through-hole 26 may be punched and formed with a press machine.

  In the first pad 2 of the second embodiment, the hole 26 h may not be provided at the corner of the through hole 26. The shape of the through hole 26 may be, for example, a rectangle similar to the concave portion 23 (see FIG. 2) of the first embodiment.

[Modification of each embodiment]
A modification of the first embodiment and the second embodiment will be described. FIG. 23 is a diagram illustrating a vibration characteristic of a pad according to a modification of each embodiment. The combination of the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 with respect to the natural frequency F0 of the disk rotor 4 is not limited to the exemplified one. In each of the above embodiments, it has been described that the natural frequency F1 of the first pad 2 is set to a value on the side opposite to the natural frequency F0 side of the disc rotor 4 with respect to the natural frequency F2 of the second pad 3. For example, as shown in FIG. 8, when the natural frequency F0 of the disk rotor 4 is higher than the natural frequency F2 of the second pad 3, the natural frequency lower than the natural frequency F2 of the second pad 3. A first pad 2 having a frequency F1 was used. However, it is considered that noise can be suppressed even with combinations other than these combinations.

  For example, as shown in FIG. 23, even if the natural frequency F0 of the disc rotor 4 exists between the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3, Suppression is possible. The frequency difference ΔF1 between the natural frequency F1 of the first pad 2 and the natural frequency F0 of the disk rotor 4 is represented as a frequency difference ΔF2 between the natural frequency F2 of the second pad 3 and the natural frequency F0 of the disk rotor 4. It is possible to make it larger. In this case, the vibration generated when the disk rotor 4 is braked by the pair of pads 2 and 3 is greater than when the natural frequency F1 of the first pad 2 and the natural frequency F2 of the second pad 3 are equal. It is considered that the natural frequency F1 of the first pad 2 is different from the natural frequency F2 of the second pad 3 so as to decrease.

  The contents disclosed in each of the above embodiments and modifications can be executed in appropriate combination.

DESCRIPTION OF SYMBOLS 1 Disc brake 2 1st pad 3 2nd pad 4 Disc rotor 6 Plate-shaped member 8 Elastic member 10 Brake pad 21 Back plate 22 Friction material 23 Recessed part 23g Interference part 23h Hole part 24 Surface 25 Back surface 26 Through-hole 26g Interference part 26h Hole Part E1 Young's modulus of plate member E2 Young's modulus of back plate F1 Natural frequency of first pad (first bending)
F2 Natural frequency of the second pad (first bending)
γ1 Specific gravity of the plate member γ2 Specific gravity of the back plate

Claims (7)

A pair of pads facing each other across the disk rotor in the axial direction of the disk rotor,
Each of the pair of pads has a friction material and a back plate that supports the friction material,
One of the pair of pads is
A recess formed on the friction material side surface or the friction material side opposite surface of the back plate;
Unlike the material of the back plate that the one has, a plate-like member fitted in the recess,
Have
The brake pad according to claim 1, wherein the one natural frequency is different from the other natural frequency. The brake pad according to claim 1, wherein the concave portion and the plate-like member are disposed in a central portion of the back plate that the one has. A pair of pads facing each other across the disk rotor in the axial direction of the disk rotor,
Each of the pair of pads has a friction material and a back plate that supports the friction material,
One of the pair of pads is
A through hole penetrating the back plate in the axial direction;
Unlike the material of the back plate that the one has, the plate-like member fitted in the through hole,
Have
The brake pad according to claim 1, wherein the one natural frequency is different from the other natural frequency. The brake pad according to claim 3, wherein the through hole and the plate-like member are disposed in a central portion of the back plate that the one has. The surface on the opposite side to the said friction material side in the said plate-shaped member exists on the same surface as the surface on the opposite side to the said friction material side in the said back plate which said one has. Brake pad as described. The brake pad according to any one of claims 1 to 5, wherein an elastic member is interposed between the plate member and the back plate of the one. A recess forming step of forming a substantially rectangular recess on the surface opposite to the friction material side of the back plate of the pad;
A hole forming step of forming holes at the four corners of the recess and removing the interference with the corners of the rectangular plate-shaped member;
A fitting step of fitting the plate-like member made of a material different from the back plate into the recess;
A method for manufacturing a brake pad, comprising:

Images