JP2016151277A - Vehicular disk brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular disk brake enabling a friction pad to be appropriately spaced apart from a disk rotor when a braking action is released during a period from a new state of the friction pad to just before its full wearing state.SOLUTION: A pad returning spring 11 comprises an engaging part 11a engaged with an ear piece 6a; a first extending piece 11c extending from the engaging part 11a toward a counter-disk rotor through a first curved part 11b; a second extending piece 11e formed by bending back the extremity end of the first extending piece 11c toward a disk rotor through a second curved part 11d; and an abutting part 11f arranged at the extremity end of the second extending piece 11e and abutted against a counter disk rotor side surface of a caliper supporting arm. The first extending piece 11c is arranged to be inclined gradually toward outside of a friction pad from the first curved part 11b toward the second curved part 11d under its free state and at the same time it approaches to a parallel state in respect to a disk axis as a friction pad 6 is moved to the disk rotor side and its displacement amount is gradually decreased.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle disc brake, and more particularly to a vehicle disc brake including a pad return spring that forcibly separates a friction pad from a disc rotor when braking is released.

  A caliper support arm is extended to a caliper bracket fixed to the vehicle body, and the friction pad is disposed between the caliper support arm and both sides of the back plate of a pair of friction pads arranged with the disc rotor interposed therebetween when braking is released. 2. Description of the Related Art A vehicular disc brake is known in which a pad return spring that urges the disc toward the disc rotor side is disposed. As this pad return spring, a back plate mounting portion attached to the side of the back plate, and extending from the back plate mounting portion, the tip is brought into contact with the caliper support arm, and the friction pad is attached to the anti-disk rotor side when braking is released. There was a thing provided with the pad return part which urges (for example, refer to patent documents 1).

JP 2000-220670 A

  However, in the above-mentioned Patent Document 1, since the urging force of the pad return spring increases according to the amount of displacement, for example, the friction pad wears out. The urging force that separates the friction pad increases, and the friction pad may be retracted greatly. For this reason, the distance between the friction pad and the disk rotor is increased, which may adversely affect the brake operation feeling.

  Accordingly, an object of the present invention is to provide a vehicle disc brake capable of properly separating the friction pad from the disc rotor when the brake is released from when the friction pad is new to just before full wear.

  In order to achieve the above object, a vehicle disc brake according to the present invention includes a caliper bracket fixed to a vehicle body, and a pair of caliper support arms that support the caliper body extending from the outer edge of the disc rotor to the disc axial direction. The caliper support arm is provided with a pad guide portion corresponding thereto, and ear pieces respectively protruding from both side portions of the back side of the friction pad disposed with the disc rotor interposed therebetween are supported by the pad guide portion, In a vehicle disc brake in which a pad return spring is disposed between the piece and the caliper support arm to urge the friction pad toward the disc rotor side when braking is released, the pad return spring is locked to the ear piece. A first extending piece that extends from the engaging part to the side opposite to the disc rotor via the first bending part, and a tip of the first extending piece is connected to the second bay. A second extension piece formed by bending back to the disk rotor side through a portion, and a contact portion provided at the tip of the second extension piece and abutting the side surface of the caliper support arm opposite to the disc rotor. In the free state in which the locking portion is locked to the ear piece, the first extending piece is gradually inclined outward from the friction pad toward the second bending portion from the first bending portion. When the friction pad is assembled to the pad guide portion and the contact portion is brought into contact with the side surface of the anti-disc rotor, the first extension piece approaches a state parallel to the disc shaft, and the friction pad As the disk rotor moves toward the disk rotor, the first extending piece further approaches a state parallel to the disk axis, and the amount of displacement gradually decreases.

  The cross-sectional area of the second extending piece is preferably smaller than the cross-sectional area of the first extending piece. Further, the width dimension of the second extension piece may be narrower than the width dimension of the first extension piece, and the second extension piece may be formed with a long hole. .

  According to the disc brake of the present invention, the pad return spring generates an urging force that presses the friction pad toward the disc rotor side by the displacement of both the first extending piece and the second piece protruding piece in the initial braking state. As the friction pad moves to the disk rotor side, the first extending piece approaches a state parallel to the disk shaft, the amount of displacement gradually decreases, and the increase in the urging force of the first extending piece decreases. 2. The friction pad is separated from the side surface of the disk rotor when the brake is released by the urging force of the extending piece.

  Further, in the state immediately before the friction pad lining is fully worn, the friction pad back plate approaches the disk rotor during braking, but the urging force of the pad return spring changes as the friction pad moves in the disk axial direction. Since it is a so-called non-linear characteristic spring, the urging force of the pad return spring gradually increases as the back plate approaches the disk rotor, and the friction pad may be greatly retracted when braking is released as in the conventional case. Therefore, the brake operation feeling can be kept good.

  Also, by forming the cross-sectional area of the second extending piece smaller than the cross-sectional area of the first extending piece, the urging force of the pad spring increases more gradually as the friction pad back plate approaches the disk rotor. Can be made. Furthermore, by forming the width dimension of the second extension piece narrower than the width dimension of the first extension piece, the cross-sectional area of the second extension piece is easily made smaller than the cross-sectional area of the first extension piece. As well as space saving. Further, by forming the long hole in the second extending piece, the cross-sectional area of the second extending piece can be easily made smaller than the cross-sectional area of the first extending piece, and the length and shape of the long hole can be reduced. By changing, it is possible to adjust the urging force of the second extending piece. Furthermore, even if an external force in the twisting direction is applied to the second extending piece, it is dispersed on both sides of the long hole, so that it is possible to avoid the stress caused by the external force from being concentrated on a part as much as possible. it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional plan view of an essential part of a vehicle disc brake showing a first embodiment of the present invention. It is a principal part sectional front view of a disk brake for vehicles similarly. It is a principal part cross-sectional rear view of the disk brake for vehicles similarly. It is explanatory drawing which similarly shows the displacement state of a pad return spring. It is a cross-sectional top view of the disk brake for vehicles similarly. FIG. 3 is a cross-sectional plan view of the vehicle disc brake immediately before the friction pad is fully worn. 1 is a front view of a vehicle disc brake showing a first embodiment of the present invention. FIG. 2 is a partially sectional rear view of the vehicle disc brake. It is a top view of the disk brake for vehicles similarly. It is a perspective view of the friction pad which similarly assembled | attached the pad return spring. It is a principal part sectional front view of the disc brake for vehicles in which the example of the 2nd form of the present invention is shown. It is a principal part sectional top view of a disk brake for vehicles similarly. It is a perspective view of the friction pad which similarly assembled | attached the pad return spring.

  FIG. 1 to FIG. 10 are views showing one embodiment of a vehicle disc brake according to the present invention. An arrow A indicates the rotation direction of a disc rotor that rotates integrally with a wheel when the vehicle moves forward. The disk entry side is assumed to be when the vehicle is moving forward.

  The disc brake 1 according to this embodiment 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 3a and 3a of the caliper bracket 3. Further, a caliper body 5 supported so as to be movable in the disk axial direction via a pair of slide pins 4 and 4 is opposed to the inside of the action part 5a and reaction part 5b of the caliper body 5 with the disk rotor 2 interposed therebetween. It consists of a pair of friction pads 6 and 6 arranged.

  The caliper body 5 is composed of the above-described action part 5a and reaction part 5b arranged 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 Are provided with a cylinder hole 5d opened on the disk rotor 2 side and a reaction force claw 5e on the reaction portion 5b. The cylinder hole 5d accommodates a bottomed cylindrical piston 7. The piston 7 moves the cylinder hole 5d in the direction of the disk rotor by the hydraulic pressure supplied to the hydraulic chamber 8 defined on the cylinder hole bottom side. It is supposed to move. Further, vehicle body mounting arms 5f and 5f are projected from the side of the action portion 5a, and the above-mentioned slide pins 4 are projected from mounting bolts 9 at the tips of the vehicle body mounting arms 5f. ing.

  The caliper support arms 3a and 3a span the outer edge of the disc rotor 2 in the disc axial direction while sandwiching both sides of the bridge portion 5c from both sides of the caliper bracket 3, and further, on the other side of the disc rotor 2, the reaction portion 5b. The shape extends along the side wall of the disc toward the center of the disc.

  Each caliper support arm 3a is provided with a guide hole 3b for accommodating the slide pin 4 described above, and the four caliper support arms 3a and 3a are respectively opposed to each other at the respective sides of the disc rotor 2. A pad guide groove 3c (pad guide portion of the present invention) is provided. Each pad guide groove 3c is formed in a U-shape having a disk radial direction outer side surface 3d, a disk radial direction inner side surface 3e, and an opposing surface 3f connecting both side surfaces 3d, 3e. The ear pieces 6a of the friction pad 6 are inserted through the retainer 10, respectively.

  Each friction pad 6 has ear pieces 6a, 6a projecting from both sides of the back plate 6b, and a lining 6c attached to one side surface of the back plate 6b. The ear piece 6a is formed in a stepped shape in which both the disk rotation direction end faces 6d and 6d have a protruding length on the outer side in the disk radial direction shorter than a protruding length on the inner side in the disk radial direction. On the outer side in the disk radial direction of the other side surface of each ear piece 6a, an engaging convex portion 6e formed by cutting out a part of the cylindrical convex portion in the axial direction is formed, and a pad return spring is formed on the engaging convex portion 6e. 11 are respectively attached.

  The pad retainer 10 is attached to the pad guide grooves 3c, 3c on both sides of the disk rotor on the disk insertion side or the disk extraction side, and a pair of retainer portions 10a, 10a for guiding the movement of the ear piece 6a in the disk axial direction. A connecting piece 10b that connects the pair of retainer portions 10a and 10a across the outer edge of the disk rotor 2 is provided. The inner piece 10c of each retainer portion 10a is formed to be inclined outward in the disk rotor radial direction, and is biased outward in the disk radial direction of the ear piece 6a to prevent the friction pads 6 and 6 from rattling.

  The pad return spring 11 includes a locking portion 11a that is locked to the ear piece 6a, and a first extending piece 11c that extends from the locking portion 11a to the side opposite to the disc rotor via the first curved portion 11b. A second extension piece 11e formed by bending the tip end of the first extension piece 11c back to the disk rotor side via the second bending portion 11d, and a tip of the second extension piece 11e, And an abutting portion 11f that abuts against the anti-disk rotor side surface 3g of the caliper support arm 3a. Further, the engaging portion 11a is formed with an insertion hole 11g having the same shape as the cross-sectional shape of the engaging convex portion 6e. The width dimension of the 2nd extension piece 11e is formed narrower than the width dimension of the 1st extension piece 11c, and the contact part 11f is formed in the circular arc shape by which the caliper bracket side is convex.

  The pad return spring 11 is assembled to the ear piece while being prevented from rotating by inserting the insertion hole 11g into the engagement convex part 6e of the ear piece 6a and crimping the engagement convex part 6e. In the free mode, the first extending piece 11c is gradually inclined to the outside of the friction pad from the first bending portion 11b toward the second bending portion 11d (P1 in FIG. 4). Further, the ear pieces 6a, 6a of the friction pad 6 are inserted into the pad guide grooves 3c, 3c with the pad retainer 10 attached thereto from the side opposite to the disc rotor, and the contact portion 11f is placed on the anti-disc of the caliper support arm 3a. Each friction pad 6 is assembled to the pad guide groove 3c in contact with the rotor side surface 3g. At this time, the first extending piece 11c approaches the state parallel to the disk axis CL1 from the inclined state (P2 in FIG. 4).

  In the disc brake 1 formed as described above, when the pressurized hydraulic fluid is supplied to the hydraulic pressure chamber 8 by the driver's braking operation, the piston 7 moves forward in the cylinder hole 5d, and the operating portion 5a side The friction pad 6 is pressed against one side of the disk rotor 2. Next, the reaction force causes the caliper body 5 to move toward the action part while being guided by the slide pins 4, 4, and the reaction force claw 5 e presses the friction pad 6 on the reaction part side against the other side of the disk rotor 2. To do. On the other hand, when the above-described braking is released, the piston 7 and the reaction force claw 5e retreat to the position at the time of starting the braking.

  At this time, the pad return spring 11 is displaced in accordance with the movement of the friction pad 6 in the disk axis direction. However, in the initial braking state, the first extension piece 11c is parallel to the disk axis CL1 via the first bending portion 11b. And the second piece 11e is displaced so as to approach the friction pad 6 via the second bending portion 11d, and the first extension piece 11c and the second extension piece 11e are displaced. Both generate an urging force that presses the friction pad 6 toward the side opposite to the disk rotor. Further, as the friction pad 6 moves to the disk rotor side, the first extending piece 11c further approaches a state parallel to the disk axis CL1, and the amount of displacement gradually decreases, mainly the second extending piece 11e. The urging force due to the displacement of the pressure increases, and the friction pad 6 is pressed toward the non-disk rotor side. (P3 in FIG. 4).

  When the lining 6c is about to be fully worn, the back plate 6b of the friction pad 6 comes close to the disc rotor 2, and the pad return spring 11 is attached to the first extending piece 11c during braking. As the increase in force gradually decreases, and when a load is mainly applied to the second extending piece 11e, the second extending piece 11e gradually curves in a protruding shape toward the disk rotor side, and the urging force increases. . Thus, the pad return spring 11 exhibits the characteristics of a so-called non-linear characteristic spring, and as the back plate 6b approaches the disk rotor 2, the urging force gradually increases, so that braking is performed as in the conventional case. The brake pad feeling can be satisfactorily maintained without greatly retracting the friction pad 6 at the time of release. Furthermore, since the width dimension of the 2nd extension piece 11e is formed narrowly, space saving can be achieved. (P4 in FIG. 4 and FIG. 6)

  FIGS. 11 to 13 show a second embodiment of the present invention. Components that are the same as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. . In the pad return spring 12 of this embodiment, the first extension piece 11c and the second extension piece 12a have the same width dimension, and a substantially rectangular long hole 12b is formed in the second extension piece 12a. ing. Thereby, the cross-sectional area of the 2nd extension piece 12a can be made smaller than the cross-sectional area of the 1st extension piece 11c, and the increase of the urging | biasing force by the displacement of the 2nd extension piece 12a can be made loose. Moreover, adjustment of the urging | biasing force of the 2nd extension piece 12a can be aimed at easily by changing the length and shape of the long hole 12b. Further, even if an external force in the twisting direction is applied to the second extending piece 12a, the stress is caused by the external force from being concentrated on a part as much as possible because it is distributed to both sides of the long hole 12b. be able to.

  Note that the present invention is not limited to the above-described embodiments, and the structure of the engaging portion of the pad return spring is arbitrary. The engaging portion is formed in a U-shape and is engaged with the ear piece interposed therebetween. Etc. Further, a plurality of round holes and long holes may be formed in the second extending piece, and the cross-sectional area of the second extending piece may be smaller than the cross-sectional area of the first extending piece. Furthermore, the friction pad may have any other shape as long as it has an ear piece, and the pad guide portion may have any shape as long as it can support the ear piece. Further, the shape of the caliper body is not limited to this embodiment, and is arbitrary.

DESCRIPTION OF SYMBOLS 1 ... Vehicle disc brake, 2 ... Disc rotor, 3 ... Caliper bracket, 3a ... Caliper support arm, 3b ... Guide hole, 3c ... Pad guide groove, 3d ... Disc radial direction outer surface, 3e ... Disc radial direction inner surface, 3f ... opposing surface, 3g ... anti-disc rotor side, 4 ... slide pin, 5 ... caliper body, 5a ... action part, 5b ... reaction part, 5c ... bridge part, 5d ... cylinder hole, 5e ... reaction force claw, 5f ... Body mounting arm, 6 ... friction pad, 6a ... ear piece, 6b ... back plate, 6c ... lining, 6d ... end face in the disk rotation direction, 6e ... engagement convex part, 7 ... piston, 8 ... hydraulic chamber, 9 ... installation Bolt, 10 ... Pad retainer, 10a ... Retainer part, 10b ... Connection piece, 10c ... Inner piece, 11 ... Pad return spring, 11a ... Locking part, 11b ... First bending part, 11c ... First extension Piece, 11d ... second curved portion, 11e ... second extension pieces, 11f ... contact portion, 11g ... insertion holes, 12 ... pad return spring, 12a ... second extension pieces, 12b ... elongated hole

Claims (4)

A caliper bracket fixed to the vehicle body spans the outer edge of the disc rotor in the disc axial direction, and a pair of caliper support arms for supporting the caliper body is extended, and a pad guide portion is provided corresponding to the caliper support arm, Ear pieces projecting from both sides of the back side of the friction pad disposed with the disc rotor interposed therebetween are supported by the pad guide part, and the friction between the ear pieces and the caliper support arms is released when braking is released. In a vehicle disc brake having a pad return spring that urges the pad to the side opposite to the disc rotor,
The pad return spring includes a locking portion that is locked to the ear piece, a first extension piece that extends from the locking portion to the side opposite to the disk rotor via a first curved portion, and the first extension piece. A second extending piece formed by bending the leading end of the protruding piece back to the disk rotor side through the second bending portion; and a side surface of the caliper supporting arm opposite to the disk rotor provided at the leading end of the second extending piece And a contact portion that contacts the
The first extending piece is provided so as to be gradually inclined to the outside of the friction pad from the first bending portion toward the second bending portion in a free state in which the locking portion is locked to the ear piece. And
When the friction pad is assembled to the pad guide portion and the abutting portion is brought into contact with the side surface of the anti-disc rotor, the first extending piece approaches a state parallel to the disc axis, and the friction pad is brought into contact with the disc rotor. As the vehicle moves to the side, the first extending piece further approaches a state parallel to the disc shaft, and the amount of displacement gradually decreases.   The vehicle disc brake according to claim 1, wherein a cross-sectional area of the second extending piece is smaller than a cross-sectional area of the first extending piece.   3. The vehicle disc brake according to claim 1, wherein a width dimension of the second extension piece is narrower than a width dimension of the first extension piece.   The vehicular disc brake according to claim 1, wherein the second extending piece is formed with a long hole.

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