JP5057174B2 - Disc brake - Google Patents

Description

  The present invention relates to a disc brake.

  A hydraulic disc brake used in a braking device for a vehicle such as an automobile includes a disc rotor that rotates together with wheels and a pair of disc rotors disposed on both sides of the disc rotor, as described in Patent Document 1, for example. The brake pad, the caliper supported on the vehicle body side and having a cylinder bore facing the back side of the brake pad, and a piston slidably inserted into the cylinder bore are generally constituted. Then, hydraulic pressure is supplied from a hydraulic pressure source such as a master cylinder to the cylinder bore to advance the piston, and the brake pad is pressed against the disc rotor to generate a braking force.

JP 2008-249123 A

  Conventionally, in such disc brakes, brake noise during braking has been a problem. The cause of the brake squeal is the vibration of the brake pad caused by the fluctuation of the frictional force between the disc rotor and the brake pad during braking, and noise is generated by transmitting this vibration to each part of the disc brake.

  An object of the present invention is to provide a disc brake that suppresses vibration of a brake pad during braking that causes brake noise.

In order to solve the above problems, the present invention provides a disc brake that generates a braking force by pressing a brake pad on a disc rotor.
A mounting opening is provided in a friction lining that is pressed against the disk rotor of the brake pad, and a dynamic vibration absorber including a mass element and a spring element is mounted in the mounting opening, and the mass element is at least partially a friction material, The friction material is pressed against the disk rotor together with the friction lining of the brake pad.

  With the disc brake according to the present invention, the vibration of the brake pad during braking can be suppressed by the dynamic vibration absorber.

It is a perspective view of a brake pad of a disc brake concerning one embodiment of the present invention. It is a longitudinal cross-sectional view by the AA line of the brake pad shown in FIG. It is a perspective view of the dynamic vibration damper with which the brake pad shown in FIG. 1 is mounted | worn. It is a longitudinal cross-sectional view by the BB line of the dynamic vibration damper shown in FIG. 1 is a longitudinal sectional view of a disc brake according to an embodiment of the present invention. It is a figure which shows the primary bending vibration of the brake pad of a disc brake. It is a figure which shows the primary torsional vibration of the brake pad of a disc brake. It is a figure which shows the secondary torsional vibration of the brake pad of a disc brake. It is a graph showing the resonance curve of the brake pad of the disc brake which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 5, the disc brake 1 according to the present embodiment is a caliper floating disc brake, which is a disc rotor 2 that rotates together with wheels, a carrier 3 that is fixed to the vehicle body side, and a carrier 3. The caliper body 4 is supported so as to be movable along the axial direction of the disk rotor 2, and is disposed on both sides of the disk rotor 2, and is supported by the carrier 3 so as to be movable along the axial direction of the disk rotor 2. And a pair of brake pads 5.

  The caliper body 4 is provided with a cylinder bore 6 so as to face one brake pad 5, and a claw portion 7 is integrally formed so as to straddle the disk rotor 2 and face the other brake pad 5. A piston 9 is slidably inserted into the cylinder bore 6 via a piston seal 8. A dust boot 10 is provided between the opening edge of the cylinder bore 6 and the piston 9. A port 11 for supplying hydraulic pressure into the cylinder bore 6 is provided at the bottom of the cylinder bore 6.

  When a hydraulic pressure is supplied from a hydraulic pressure source such as a master cylinder into the cylinder bore 6 through the port 11, the piston 9 moves forward to press one brake pad 5 against the disc rotor 2, and the reaction force causes the caliper body 4 to move. The claw portion 7 presses the other brake pad 5 against the disc rotor 2, thereby generating a braking force. When the hydraulic pressure from the hydraulic pressure source is released, the piston 9 moves backward, the brake pad 5 is separated from the disc rotor 2, and braking is released.

Next, the brake pad 5 which is the main part of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the brake pad 5 has substantially the same shape as the back plate 11 on one side of a back plate 11 that is a substantially arc-shaped flat plate member along the sliding surface of the disk rotor 2. Thus, a friction lining 12 slightly smaller than the back plate 11 is fixed. Both end portions in the rotational direction of the disk rotor 2 of the back plate 11 are torque receiving portions that contact a torque receiving surface (not shown) of the carrier 3 and receive braking torque, and rectangular guides are provided to these torque receiving portions. The part 13 protrudes. And the guide part 13 is inserted in the guide groove formed in the torque receiving surface of the carrier 3, and the brake pad 5 is slidably supported along the axial direction of the disk rotor 2. As shown in FIG.

  The friction lining 12 generates frictional force, that is, braking force in contact with the disk rotor 2. The friction lining 12 has chamfered portions 12A formed at corners at both ends in the rotational direction of the disk rotor 2, and a wear warning groove 14 extending in the radial direction at the center. The pair of brake pads 5 are supported by the carrier 3 with the friction lining 12 facing the disc rotor 2 and the back plate 11 facing the piston 9 or the claw portion 7 via the pad spring 15.

  The brake pad 5 is provided with two dynamic vibration absorbers 16. As shown in FIGS. 3 and 4, the dynamic vibration absorber 16 includes a bottomed cylindrical base member 17 and a columnar friction mass member 18 fixed to the bottom of the base member 17.

  The base member 17 is made of steel having flexibility, the outer peripheral portion of the bottom portion is cut out in an arc shape, the disc portion 20 of the bottom portion is separated from the cylindrical portion 19, and the remaining portion is cut off. As the cantilever 21, the disk portion 20 is elastically supported. The cylindrical portion 19 of the base member 17 has an axial length that matches the plate thickness of the back plate 11 of the brake pad 5, and an outer flange 22 is formed at the end on the opening side.

  The friction mass member 18 is the same friction material as the friction lining 12 of the brake pad 5 and has a diameter that matches the disc portion 20 of the base member 17 and an axial length that matches the thickness of the friction lining 12. Yes. The friction mass member 18 is fixed to the disc portion 20 of the base member 17. The dynamic vibration absorber 16 constitutes a vibration system with the friction mass member 18 as a mass element and the cantilever 21 as a spring element. By using the cantilever 21 as a spring element, it is possible to easily adjust the spring constant by adjusting the cross-sectional area of the cantilever 21.

  As shown in FIGS. 1 and 2, the brake pad 5 is provided with a circular mounting opening 23 that penetrates from the back plate 11 to the friction lining 12. In the dynamic vibration absorber 16, the friction mass member 18 is inserted into the mounting opening 23 from the back plate 11 side, the cylindrical portion 19 of the base member 17 contacts the mounting opening 23 of the back plate 11, and the outer flange 22 contacts the back plate 11. Up to now, it is attached to the brake pad 5 by fixing by press-fitting, screwing or bonding. At this time, the surfaces of the friction mass member 18 and the friction lining 12 are flush with each other. Here, by providing the dynamic vibration absorber 16 as an assembly, it can be easily attached to the brake pad 5, and the manufacture of the brake pad is facilitated. The attachment opening 23 may not pass through the back plate 11, and the outer flange 22 of the cylindrical portion 19 may be omitted, and the dynamic vibration absorber 16 may be attached from the friction lining 12 side. Even in this case, the dynamic vibration absorber 16 is fixed so that the surfaces of the friction mass member 18 and the friction lining 12 are flush with each other.

  As shown in FIG. 6, the present embodiment mainly suppresses primary bending vibration in which both ends of the brake pad 5 are displaced along the axial direction of the disc rotor 2 with respect to the central portion in the rotational direction of the disc rotor 2. Is for. For this reason, the two dynamic vibration absorbers 16 are disposed in the vicinity of the linear guide portion 13 connecting the guide portions 13 at both ends of the brake pad 5 that is largely displaced by the primary bending vibration. In the dynamic vibration absorber 16, the mass of the friction mass member 18 and the spring constant of the cantilever 21 are set so that the natural frequency coincides with that of the brake pad 5 with respect to the primary bending vibration of the brake pad 5 described above. Has been.

Next, the operation of the present embodiment configured as described above will be described.
When the primary bending vibration shown in FIG. 6 occurs in the brake pad 5 during braking of the disc brake 1, the two dynamic vibration absorbers 16 having the same natural frequency as the brake pad 5 vibrate in the opposite phase to the brake pad 5. Thus, the vibration of the brake pad 5 is suppressed. Thereby, generation | occurrence | production of the brake squeal at the time of braking can be suppressed.

  When the disc brake 1 is braked, the brake pad 5 is restrained at the center part by the pressure of the piston 9 and the claw part 7, so that both end parts are displaced and the primary bending vibration shown in FIG. By suppressing the primary bending vibration by the dynamic vibration absorber 16, it is possible to effectively suppress the occurrence of brake squeal.

  As described above, the present embodiment mainly corresponds to the primary bending vibration shown in FIG. 6, but as a result of simulation using the finite element method, the primary of the brake pad 5 shown in FIG. It has been found that the dynamic vibration absorber 16 acts on the torsional vibration and the secondary torsional vibration shown in FIG. 8 to suppress the vibration.

  FIG. 9 represents a resonance curve of the brake pad 5 with the vertical axis (logarithm) representing the acceleration / force of the frequency response function and the horizontal axis representing the frequency. In FIG. 9, the solid line represents the case where the dynamic vibration absorber 16 is provided, and the broken line represents the case where the dynamic vibration absorber 16 is not provided. From FIG. 9, the vibration of the brake pad 5 is effectively reduced with respect to the primary bending vibration (see area a), primary torsional vibration (see area b), and secondary torsional vibration (see area c). It turns out that it suppresses.

  Further, when braking is repeated and the friction lining 12 of the brake pad 5 is worn, the mass of the brake pad 5 decreases and the natural frequency of the friction pad 5 increases. On the other hand, the friction mass member 18 of the dynamic vibration absorber 16 also wears in contact with the disk rotor 2 together with the friction lining 12, and its mass decreases, so that the natural frequency of the dynamic vibration absorber 16 also increases. As a result, regardless of the amount of wear of the friction lining 12, the natural frequencies of the brake pad 5 and the dynamic vibration absorber 16 can be substantially matched, and the vibration damping effect can be maintained.

  At this time, as indicated by phantom lines in FIG. 4, the friction mass member 18 may be formed in a tapered shape, and the change in mass with respect to wear may be adjusted by the taper angle. In this case, the inner peripheral surface of the attachment opening 23 of the friction lining 12 may be a tapered surface along the taper angle of the friction mass member 18. In the above embodiment, the friction mass member 18 is made of the same friction material as that of the friction lining 12 of the brake pad 5. However, the friction mass member 18 may be made of a different material as long as the mass decreases with wear of the friction lining 12. Thus, the amount of wear on the friction lining 12 may be adjusted. Further, the friction mass member 18 that is a mass element may not be entirely a friction material, and if the tip side portion that contacts the disc rotor together with the friction lining 12 of the brake pad 5 is a friction material, the base end side is The mass element may be made of other materials such as metal, stone, and ceramic.

  The present invention can be easily applied to a conventional disc brake by providing the mounting opening 23 at a necessary portion of the brake pad and mounting the dynamic vibration absorber 16, so that it can be easily applied to an existing disc brake. The cost is low. In the above embodiment, a caliper floating type hydraulic disc brake is described as an example. However, the present invention is not limited to this, and the present invention is a disc brake that presses a brake pad against a disc rotor to generate a braking force. As long as there is a caliper floating type, an opposed piston type, etc., it can be applied to any type, such as a hydraulic type, an electric type, and a mechanical type.

  In the above-described embodiment, the dynamic vibration absorber 16 uses the cantilever 21 as a spring element. However, if the necessary natural frequency is obtained, the spring element may have other shapes such as a plurality of cantilever beams and doubly supported beams. It is good. In the above embodiment, as described above, the dynamic vibration absorber 16 is provided mainly corresponding to the primary bending vibration shown in FIG. 6, but in addition, depending on the vibration mode of the brake pad 5, The vibration of the brake pad 5 can be suppressed by disposing the dynamic vibration absorber 16 having an appropriate natural frequency at the portion to be displaced.

  1 Disc brake, 2 Disc rotor, 5 Brake pad, 12 Friction lining, 16 Dynamic vibration absorber, 18 Friction mass member (mass element), 12 Cantilever beam (spring element), 23 Mounting opening

Claims (1)

In the disc brake that generates braking force by pressing the brake pad on the disc rotor,
A mounting opening is provided in a friction lining that is pressed against the disk rotor of the brake pad, and a dynamic vibration absorber including a mass element and a spring element is mounted in the mounting opening, and the mass element is at least partially a friction material, The disc brake, wherein the friction material is pressed against the disc rotor together with the friction lining of the brake pad.