JP2012202494A - Disk brake for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk brake for a vehicle capable of properly pulling back a friction pad by a pad returning spring when releasing braking.SOLUTION: A pad returning spring 7 for pulling back friction pads 6 to a counter disc rotor side when releasing braking, is suspended outside in disc radial direction of a pair of friction pads 6 arranged on both sides of a disc rotor 2. The pad returning spring 7 includes a pair of friction pad engagement parts 7c which engage with engagement holes 6d opened outside the disc radial direction of the pair of friction pads 6, and a spring part 7b which connects the pair of friction pad engagement parts 7c and has a resilient force along a direction separating both friction pad engagement parts 7c under such condition as the pair of friction pads 6 are arranged on both sides of the disc rotor. The engagement holes 6d have the depth as deep as the intermediate part in disc radial direction of the friction pads 6, and the friction pad engagement part 7c extends as far as a bottom part side from an opening side of the engagement hole 6d.

Description

  The present invention relates to a vehicle disc brake mounted on a traveling vehicle such as an automobile or a motorcycle or a three-wheeled vehicle. More specifically, the present invention relates to a vehicle disc brake provided with a pad return spring that pulls a friction pad back to the non-disc rotor side when braking is released. .

  Conventionally, in a disk brake for a vehicle, a pair of friction pads arranged on both sides of a disk rotor is suspended on the outer side in the disk radial direction by a pad return spring that pulls the pair of friction pads back to the opposite disk rotor side when braking is released. There is. The pad return spring includes a folded portion formed by folding a wire spring into a substantially V shape, a pair of spring portions extending in a direction away from the folded portion, and a tip from the spring portion toward the friction pad side. A friction pad engaging portion that protrudes, and the friction pad engaging portion is mounted in an engagement hole that opens outward in the disk radial direction of the pair of friction pads, and the folded portion is disposed between the pair of friction pads. There are some which are arranged on the outer circumference side of the disk rotor (for example, see Patent Document 1 or 2).

JP-A-8-145089 Japanese Utility Model Publication No. 5-50175

  However, in the above-mentioned Patent Documents 1 and 2, when the brake is released, the friction pad engaging portion of the pad return spring is engaged with the engagement hole on the outer side in the disk radial direction of the friction pad. The outer side in the disk radial direction is pulled back from the disk rotor, but the inner side in the disk radial direction of the friction pad away from the friction pad engaging portion is not sufficiently pulled back from the disk rotor, and the inner side in the disk radial direction of the friction pad is dragged to the disk rotor. There was a fear.

  Accordingly, an object of the present invention is to provide a vehicular disc brake that can satisfactorily pull back a friction pad when a brake is released by a pad return spring.

  In order to achieve the above object, the vehicle disc brake of the present invention has a pair of friction pads arranged on both sides of the disc rotor on the outer side in the disc radial direction, and the pair of friction pads on the side opposite to the disc rotor when the brake is released. In the vehicle disc brake in which the return pad return spring is suspended, the pad return spring includes a pair of friction pad engaging portions that engage with engagement holes that open outward in the disk radial direction of the pair of friction pads, A pair of friction pad engaging portions, and a spring portion having a resilient force in a direction to separate the friction pad engaging portions in a state where the pair of friction pads are disposed on both sides of the disc rotor. And the engagement hole has a depth to an intermediate portion in the disk radial direction of the friction pad, and the friction pad engagement portion It is characterized in that extending from the opening side to the bottom side.

  The engagement hole may have a depth corresponding to the position of the center of gravity of the friction pad. Further, the engagement hole includes a large diameter portion having an inner diameter larger than an outer shape of the friction pad engagement portion on the opening side, and a small diameter portion on which the tip end portion of the friction pad engagement portion is engaged on the bottom side. It is suitable if it is formed in the stepped shape provided with.

  According to the vehicle disc brake of the present invention, the friction pad is inserted by the friction pad engaging portion of the pad return spring to the intermediate portion in the disk radial direction of the friction pad. Since the friction pad is pulled back to the side opposite to the disk rotor while keeping the state parallel to the side surface of the disk rotor as much as possible, the friction pad can be prevented from being dragged by the disk rotor.

  In addition, the engagement hole has a depth corresponding to the position of the center of gravity in the middle of the friction pad in the radial direction of the disk, so that when the friction pad is pulled back from the disk rotor when the brake is released, the entire friction pad is pulled back better. Can do.

  Further, the engagement hole has a large-diameter portion on the opening side and a small-diameter portion on the bottom side, the distal end side of the friction pad engaging portion is locked to the small-diameter portion, and the large diameter and the proximal end side of the friction pad engaging portion When the friction pad is pulled back, the friction pad engaging portion does not come into contact with the opening of the large-diameter portion and the return force of the spring portion is applied to the friction pad disk. It can be reliably transmitted to the intermediate portion in the radial direction.

It is a principal part expanded sectional view of the disc brake for vehicles which shows one example of this invention. FIG. 3 is a partially cutaway plan view of the vehicle disc brake. It is III-III sectional drawing of FIG. FIG. 2 is a partially sectional rear view of the vehicle disc brake. It is a front view of the disk brake for vehicles similarly.

  FIGS. 1 to 5 are views showing an embodiment of a vehicle disc brake according to the present invention. An arrow A indicates a rotation direction of a disc rotor that rotates integrally with a front wheel when the vehicle moves forward. The disk entry side is when the vehicle is moving forward.

  The disc brake 1 for a vehicle includes a disc rotor 2 that rotates integrally with a wheel, a caliper bracket 3 that is fixed to a vehicle body at one side of the disc rotor 2, and caliper support arms 3 a and 3 a of the caliper bracket 3. The caliper body 5 supported so as to be movable in the disk axial direction via a pair of slide pins 4 and 4 and the action portion 5a and the reaction portion 5b of the caliper body 5 are opposed to each other with the disc rotor 2 interposed therebetween. A pair of friction pads 6, 6 are arranged, and a pad return spring 7 is suspended on the friction pads 6, 6 to pull back the friction pads 6, 6 to the side opposite to the disk rotor when braking is released.

  The caliper body 5 includes the above-described action part 5a and reaction part 5b disposed on both sides of the disk rotor 2, and a bridge part 5c that connects these parts across the outer edge of the disk rotor 2, and the action part 5a. Is provided with a cylinder hole 8 having an opening on the disk rotor 2 side. The bottomed cylindrical piston 9 is accommodated in the cylinder hole 8, and the piston 9 moves in the direction of the disk rotor through the cylinder hole 8 by the pressure liquid supplied to the hydraulic pressure chamber 10 at the bottom of the cylinder hole. ing. Further, slide pin mounting arms 5d and 5d project from the side of the action portion 5a, and the above-mentioned slide pins 4 project from mounting tips by mounting bolts at the tips of the respective slide pin mounting arms 5d. Has been.

  On the inner peripheral surface of the cylinder hole 8, an annular piston seal mounting groove 8a is provided in the middle in the axial direction, and an annular dust seal mounting groove 8b is provided on the cylinder hole opening side of the piston seal mounting groove 8a. It is installed. The piston seal mounting groove 8a is fitted with a piston seal 11 that slides fluidly and movably on the outer peripheral surface of the piston 9 and rolls back the piston with its restoring force, and the dust seal mounting groove 8b includes A dust seal 12 is slidably brought into sliding contact with the outer peripheral surface of the piston 9 to prevent dust from entering the cylinder hole.

  The caliper support arms 3a and 3a straddle the outer edge of the disc rotor 2 from both sides of the caliper bracket 3 while sandwiching both sides of the bridge portion 5c in the disc axial direction, and at the other side of the disc rotor 2, the reaction portion 5b The shape extends along the side wall toward the center of the disk. The distal ends of the caliper support arms 3a and 3a are connected by a tie rod 3b to increase the rigidity of the support arms 3a and 3a to which braking torque is applied.

  Each caliper support arm 3a is provided with a guide hole 3c for accommodating the slide pin 4 described above, and the four caliper support arms 3a and 3a have four pads facing each other on the respective side portions of the disc rotor 2. A guide portion 3d is provided. A pair of pad guide portions 3d facing each other on the side surface of the disk rotor 2 are formed in a U-shaped cross section having torque receiving surfaces 3e facing each other. A pad retainer mounting portion 3f for mounting the pad retainer 13 is provided outside the pad guide portion 3d in the disk radial direction.

  Each friction pad 6 has ear pieces 6b and 6b projecting on both sides of the back plate 6a, and a lining 6c is attached to one side surface of the back plate 6a, and the ear pieces 6b and 6b are on the disk entry side. Are supported by pad guide portions 3d and 3d on the delivery side via pad retainers 13, respectively. The back plate 6a is formed in a substantially sector shape in which the width in the disk circumferential direction on the outer side in the disk radial direction is shorter than the width in the disk circumferential direction on the inner side in the disk radial direction. On the outer side in the disk radial direction, an engagement hole 6d of the pad return spring 7 opening outward in the disk radial direction is formed.

  The pad return spring 7 is formed by bending a wire spring. The pad return spring 7 is formed by folding the central portion of the wire spring into an arc shape, and is spaced apart from both ends of the turn-up portion 7a. And a friction pad engaging portion 7c that protrudes from the tip of each spring portion 7b toward the center of the disk rotor 2, and is formed in a substantially V-shape. Yes. The friction pad engaging portion 7c is bent at a substantially right angle with respect to the spring portion 7b, and extends from the opening side of the engaging hole 6d to the bottom side. In the pad return spring 7, the friction pad engaging portions 7 c and 7 c are inserted into the engagement holes 6 d and 6 d of the friction pads 6 and 6, and the turned-back portion 7 a is connected to the outer peripheral side of the disk rotor between the friction pads 6 and 6 and the bridge. It arrange | positions between the parts 5c.

  The engagement hole 6d includes a large-diameter portion 6e having an inner diameter larger than the outer shape of the friction pad engaging portion 7c on the opening side, and a small-diameter portion 6f that engages the tip end portion of the friction pad engaging portion 7c on the bottom side. It is formed in a stepped shape, has a depth corresponding to the center of gravity G1 of the friction pad 6, and is inclined toward the center of the disc rotor 2 from the opening side toward the bottom side. Further, the engaging hole 6d formed in this way is disposed in the vicinity of the ear piece 6b on the disk insertion side, and has a depth reaching the depth of about 2/3 of the ear piece 6b in the disk radial direction. Have. The pad retainer 13 includes an attachment portion 13a attached to the pad retainer attachment portion 3f and a retainer portion 13b arranged on the pad guide portion 3d.

  In the vehicular disc brake 1 formed as described above, when the pressurized hydraulic fluid is supplied to the hydraulic pressure chamber 10 by the driver's braking operation, the piston 9 advances through the cylinder hole 8 and the action portion 5a. The friction pad 6 on the side is pressed toward the disk rotor 2 rotating in the arrow A direction. The friction pad 6 on the action side moves the pad guide grooves 3d and 3d to the disk rotor 2 side while the ear pieces 6b and 6b are guided by the pad retainers 13 and 13, and the lining 6c is moved to one side of the disk rotor 2. Slid into contact. Next, this reaction force causes the caliper body 5 to move in the direction of the action part 5a while being guided by the slide pins 4 and 4, and the reaction force claw 5e provided on the reaction part 5b side causes the friction pad 6 on the reaction part 5b side. To the other side of the disk rotor 2. The friction pad 6 on the reaction portion side moves the pad guide grooves 3d and 3d to the disk rotor 2 side while the ear pieces 6b and 6b are guided by the pad retainers 13 and 13, and the lining 6c is moved to the other side of the disk rotor 2. Slid into contact. At this time, the pad return spring 7 is elastically deformed by the folded portion 7a and the spring portions 7b and 7b as the friction pads 6 and 6 move toward the disk rotor 2, and the spring portions 7b and 7b approach each other. It becomes a state.

  On the other hand, when the above-described braking operation is released, the piston 9 rolls back with the restoring force of the piston seal 11, and the piston 9 and the reaction force claw 5e move back to the position before the braking starts, the restoring force of the pad return spring 7 As a result, the spring portions 7b and 7b return to the initial state separated from each other with the folded portion 7a as the center. A position corresponding to the center of gravity G1 of both friction pads 6 and 6 is pressed to the side opposite to the disk rotor 2 through 6f. The friction pads 6 and 6 are pulled back by moving the pad guide grooves 3d and 3d to the side opposite to the disk rotor 2 while the ear pieces 6b and 6b are guided by the pad retainers 13 and 13, and the linings 6c and 6c are pulled back. 2 apart from the side surface. At this time, the friction pad engagement portions 7c and 7c are friction pad engagements with the small diameter portions 6f and 6f having a depth corresponding to the center of gravity G1 of the friction pads 6 and 6 at the disc radial direction intermediate portion of the friction pads 6 and 6, respectively. Since the portions 7 c and 7 c are engaged, the friction pads 6 and 6 can be pulled back to the side opposite to the disk rotor while keeping the friction pads 6 and 6 in a state parallel to the side surface of the disk rotor 2 as much as possible. Thereby, the linings 6c and 6c of the friction pads 6 and 6 can be separated from the disk rotor 2 in a good state, and dragging of the friction pads 6 and 6 can be suppressed. Further, since a gap is formed between the base end side of the friction pad engaging portion 7c and the large diameter portion 6e of the engagement hole 6d, when the friction pad 6 is pulled back, the opening of the large diameter portion 6e is opened. The friction pad engaging portion 7c does not abut on the side, and the return force of the spring portion 7b can be reliably transmitted to the depth position corresponding to the center of gravity G1 of the friction pad 6. Further, the friction pad engaging portion 7c is disposed in the vicinity of the ear piece 6b on the disk entry side, and is located at a depth that reaches the depth of about 2/3 of the ear piece 6b in the disc radial direction. Therefore, when the brake is released, the vicinity of the sliding ear piece 6b can be pressed toward the anti-disk rotor side, and the friction pad 6 can be slid in a stable state toward the anti-disk rotor side.

  The present invention is not limited to the above-described embodiment, and the engagement hole formed in the friction pad only needs to have a depth to the intermediate portion in the disk radial direction, and the depth corresponding to the gravity center position of the friction pad. It doesn't have to be. Also, an engagement hole may be formed on the disk delivery side of the friction pad, and a pad return spring may be arranged on the disk delivery side, or a pad return spring may be arranged only on the disk delivery side. good. Furthermore, there may be a plurality of pistons, which can be applied to a piston-facing type disc brake, and can also be applied to a type of disc brake in which a friction pad is suspended by a hanger pin. The engagement hole formed in the friction pad may be appropriately formed at a position where the friction pad can be pulled back without tilting according to the type of the disc brake and the shape of the friction pad. It may be arranged outside the disk rotation direction. In addition, the large diameter portion of the engagement hole may be in any shape as long as the pad return spring does not come into contact with it, even if it is not cylindrical. Further, the pad return spring may be formed in a U shape.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle disc brake, 2 ... Disc rotor, 3 ... Caliper bracket, 3a ... Caliper support arm, 3b ... Tie rod, 3c ... Guide hole, 3d ... Pad guide part, 3e ... Torque receiving surface, 3f ... Pad retainer attaching part 4 ... slide pin, 5 ... caliper body, 5a ... action part, 5b ... reaction part, 5c ... bridge part, 5d ... slide pin mounting arm, 5e ... reaction force claw, 6 ... friction pad, 6a ... back plate, 6b ... Ear piece, 6 c. Lining, 6 d. Engagement hole, 6 e. Large diameter part, 6 f. Small diameter part, 7. Pad return spring, 7 a. ... Cylinder hole, 8a ... Piston seal mounting groove, 8b ... Dust seal mounting groove, 9 ... Piston, 10 ... Hydraulic chamber, 11 ... Piston seal, 12 ... Dust seal, 13 ... Paddle Over Na, 13a ... attachment portion, 13b ... retainer

Claims (3)

In the disk brake for a vehicle, wherein a pad return spring is suspended on the outer side in the disk radial direction of the pair of friction pads arranged on both sides of the disk rotor, and the pair of friction pads are pulled back to the opposite disk rotor side when braking is released. The spring connects the pair of friction pad engaging portions to a pair of friction pad engaging portions that engage with engagement holes that open outward in the disk radial direction of the pair of friction pads, and the pair of friction pads. A spring portion having a resilient force in a direction to separate the friction pad engaging portions in a state where the pads are arranged on both sides of the disc rotor, and the engaging hole is an intermediate portion in the disk radial direction of the friction pad. And the friction pad engaging portion extends from the opening side to the bottom side of the engaging hole. Disk brake. The vehicle disc brake according to claim 1, wherein the engagement hole has a depth corresponding to a center of gravity of the friction pad. The engagement hole includes a large-diameter portion having an inner diameter larger than the outer shape of the friction pad engaging portion on the opening side, and a small-diameter portion on the bottom portion side for engaging a tip portion of the friction pad engaging portion. 3. The vehicle disc brake according to claim 1, wherein the disc brake is formed in a stepped shape.

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