Disk brake

Abstract

In this disk brake, weight reduction of a caliper body is achieved while the rigidity of the caliper body is maintained by a rib part. A caliper body 6 is formed by connecting an action part 6a and a reaction part 6b through a bridge part 6c, and a rib part is provided to extend across the action part, the bridge part, and the reaction part. When the rib centerline of a second rib part 23b formed at the bridge part and the reaction-force claw centerline passing through the disk circumferential center of an intermediate reaction-force claw are virtually provided on the same line, an intermediate rib part 23 formed at a portion between adjacent cylinder holes 6h, 6i is formed, on the cylinder hole 6h side where stress to be generated in response to the force toward a bottom part in the axial direction of the cylinder hole is large, such that the rib centerline is offset from the reaction-force claw center line. A third rib part 23c formed at the reaction part 6b is formed by connecting the second rib part 23b and an intermediate reaction-force claw 6k.

Description

Disk brake

[0001] The present invention relates to a disk brake provided with a caliper body in which an operating portion having a cylinder hole disposed on one side of a disk rotor and a reaction portion having a reaction claw disposed on the other side of the disk rotor are connected by a bridge portion.

[0002] In a disk brake provided with a caliper body in which an operating portion having a plurality of cylinder holes disposed on one side of a disk rotor and a reaction portion having a reaction claw disposed on the other side of the disk rotor are connected by a bridge portion, there has been one in which a rib portion extending over the operating portion, the bridge portion, and the reaction portion is formed on the caliper body to improve rigidity. (For example, see Patent Document 1.)

[0003] International Publication No. 2019 / 240117

[0004] However, in the above-mentioned patent document, the adjacent cylinder holes are formed with different diameters, and the rib portion formed between these cylinder holes is formed with a wide width in the disk circumferential direction of the portion formed on the bridge portion so as to correspond to the diameters of the different cylinder holes. For this reason, the weight of the caliper body has tended to increase.

[0005] Therefore, an object of the present invention is to provide a disk brake that reduces the weight of the caliper body while maintaining the rigidity of the caliper body by a rib portion.

[0006] To achieve the above objective, the present invention provides a disc brake comprising a caliper body having an action portion located on one side of a disc rotor and having a plurality of cylinder holes for housing pistons, and a reaction portion located on the other side of the disc rotor and having reaction claws, connected by a bridge portion, and a rib portion formed extending across the action portion, the bridge portion and the reaction portion, wherein the rib portion is formed between adjacent cylinder holes and comprises a first rib portion formed on the action portion, a second rib portion formed on the bridge portion and the reaction portion The second rib portion is formed in a series with respect to a third rib portion, and when the rib center line passing through the circumferential center of the second rib portion in the disk direction and the reaction claw center line passing through the circumferential center of the intermediate reaction claw formed between adjacent cylinder holes in the disk direction are virtually placed on the same line, the rib center line is formed offset from the reaction claw center line on the side of the adjacent cylinder hole where the stress generated by the force toward the axial bottom side of the cylinder hole is larger, and the third rib portion is formed connecting the second rib portion and the intermediate reaction claw.

[0007] According to the disc brake of the present invention, the width of the second rib portion in the circumferential direction of the disc can be kept to the minimum necessary while maintaining the rigidity of the caliper body with the rib portion, thereby reducing the weight of the caliper body.

[0008] This is a front view of a disc brake illustrating one embodiment of the present invention. This is a rear view of the same. This is a top view of the same. This is a side view of the same. This is a cross-sectional view taken along line V-V in Figure 4. This is a cross-sectional view of the main part of a caliper body illustrating one embodiment of the present invention. This is a perspective view of a disc brake illustrating one embodiment of the present invention.

[0009] Figures 1 to 7 show an example of one embodiment of the disc brake and caliper body of the present invention. Arrow A indicates the direction of rotation of the disc rotor, which rotates integrally with the wheel when the vehicle moves forward, and the disc exit side and disc entry side described below refer to the state when the vehicle is moving forward.

[0010] The disc brake 1 comprises a disc rotor 2 that rotates integrally with a wheel (not shown), a caliper bracket 3 attached to the vehicle body on one side of the disc rotor 2, a pin-slide type caliper body 6 supported on the caliper bracket 3 so as to be movable in the disc axial direction via a pair of slide pins 4, 5, and a pair of friction pads 7, 7 arranged opposite each other on both sides of the disc rotor 2.

[0011] The caliper bracket 3 comprises a plate-shaped portion 3a disposed along one side of the disc rotor 2, and a pad support arm 3b that protrudes toward the other side, straddling the outside of the disc rotor 2 on the disc rotation side of the caliper body 6. One slide pin 4 is provided protruding from the disc rotation side of the plate-shaped portion 3a. The pad support arm 3b is provided with a pin hole (not shown) through which the other slide pin 5 is inserted. Furthermore, the pad support arm 3b is provided with a pair of pad guide grooves 3c, 3c on either side of the disc rotor 2, which guide the friction pads 7, 7 so that they can move in the disc axial direction.

[0012] The friction pad 7 consists of a lining 7a that slides against the side surface of the disc rotor 2 and a backing plate 7b that is held by the caliper bracket 3 and the caliper body 6. The backing plate 7b is provided with a lug 7c that protrudes toward the disc rotation side, a suspension piece 7d that protrudes outward in the radial direction of the disc, and a projection 7e that contacts the pad spring 11, which will be described later.

[0013] The caliper body 6 comprises an action portion 6a positioned on one side of the disc rotor, a reaction portion 6b positioned on the other side of the disc rotor, and a bridge portion 6c connecting these across the outside of the disc rotor 2. Vehicle mounting arms 6d and 6e are provided protruding from the disc rotation side and the radially inward side of the action portion 6a. The other slide pin 5 is provided protruding from the vehicle mounting arm 6d on the disc rotation side, and this other slide pin 5 is inserted through a pin hole formed in the pad support arm 3b. Furthermore, one slide pin 4 protruding from the plate-shaped portion 3a is inserted through a pin hole (not shown) formed in the radially inward vehicle mounting arm 6e, and the caliper body 6 is supported by the caliper bracket 3 via the slide pins 4 and 5 so as to be movable in the disc axial direction.

[0014] Furthermore, hanger pin support arms 6f and 6g are provided on the disc rotation side of the acting portion 6a and reaction portion 6b, at a position outside the outer circumferential surface of the disc rotor 2, protruding toward the disc rotation side from the disc rotation side surface 6t of the bridge portion 6c, and a hanger pin 8 is stretched across these hanger pin support arms 6f and 6g. The friction pads 7, 7 are suspended so as to be movable in the disc axial direction with the disc rotor 2 sandwiched between the acting portion 6a and reaction portion 6b by inserting the hanger pin 8 through the suspension piece 7d and housing the ear piece 7c in the pad guide groove 3c.

[0015] The working section 6a is provided with a large-diameter cylinder hole 6h on the disc rotation side and a small-diameter cylinder hole 6i on the disc insertion side, both opening towards the disc rotor 2. A large-diameter piston 9 is housed in the large-diameter cylinder hole 6h, and a small-diameter piston 10 is housed in the small-diameter cylinder hole 6i, both movable in the disc axial direction. A hydraulic chamber into which working fluid is introduced is defined between the pistons 9 and 10 and the cylinder holes 6h and 6i. Furthermore, on the radially outer side of the working section 6a, there is a union hole 12a that shares working fluid with the hydraulic chamber, and a bleeder boss portion 12b for mounting a bleeder 13 for removing air from the working fluid.

[0016] The reaction section 6b is provided with a disc rotation side reaction claw 6j on the disc rotation side, an intermediate reaction claw 6k at an intermediate position between cylinder holes 6h and 6i, and a disc entry side reaction claw 6m on the disc entry side. Furthermore, as shown in Figure 2, the reaction claw centerline CL2 is defined as the line extending inward and outward in the radial direction of the disc, passing through the center P1 in the width direction at the narrowest point between cylinder holes 6h and 6i (the point with the shortest disc circumferential length), i.e., the centerline in the width direction of the intermediate reaction claw 6k.

[0017] On the outer surface of the caliper body 6, a rotation-side rib portion 21 is provided on the disc rotation side, a rotation-side rib portion 22 is provided on the disc entry side, and an intermediate rib portion 23 (the rib portion of the present invention) is provided between the rotation-side rib portion 21 and the rotation-side rib portion 22, extending across the acting portion 6a, the bridge portion 6c, and the reaction portion 6b, respectively.

[0018] The intermediate rib portion 23 is formed between the cylinder holes 6h and 6i and comprises a first rib portion 23a formed on the acting portion 6a, a second rib portion 23b formed on the bridge portion 6c, and a third rib portion 23c formed on the reaction portion 6b, in a continuous manner.

[0019] As shown in Figure 5, if a conventional intermediate rib section R1 is virtually provided, the virtual line VL1 passing through its center is generally on the same line as the reaction force claw center line CL2. Therefore, when braking, the hydraulic pressure pushes the pistons 9 and 10 toward the openings of the cylinder bores 6h and 6i, causing the friction pads 7 and 7 to slide against the disc rotor 2. As a result, the stress generated is greater in the larger diameter cylinder bore 6h than in the smaller diameter cylinder bore 6i. That is, the stress generated in response to the force directed toward the axial bottom side of the cylinder bores 6h and 6i is greater on the cylinder bore 6h side than on the cylinder bore 6i side when using the cylinder bore as a reference, and greater on the disc exit side than on the disc entry side when using the bridge section as a reference.

[0020] Therefore, the rib centerline CL1 of the second rib portion 23b of the present invention is formed closer to (offset) the cylinder bore 6h side (disk rotation side), where the generated stress is greater, than the reaction force claw centerline CL2. This ensures that the generated stress is well distributed.

[0021] Furthermore, the intermediate reaction claw 6k is positioned such that the reaction claw centerline CL2 overlaps a portion of the second rib section 23b, which is offset. This configuration allows the second rib section 23b and the intermediate reaction claw 6k to be made to the minimum necessary thickness, thereby reducing weight while maintaining rigidity.

[0022] Furthermore, by offsetting the rib centerline CL1 and the reaction force claw centerline CL2, the generated stress is well distributed, so rigidity can be maintained even when excess material is removed, and the width of the second rib section 23b can be made narrower than the conventional intermediate rib section R1.

[0023] The third rib portion 23c is formed by connecting the second rib portion 23b and the intermediate reaction claw 6k. Since the rib centerline CL1 is offset toward the disc rotation side with respect to the reaction claw centerline CL2, it is formed obliquely in the disc rotation direction from the second rib portion 23b side toward the intermediate reaction claw 6k side.

[0024] As shown in Figures 5 and 6, the bridge portion 6c has an inner wall portion 6n facing the outer circumferential surface of the disc rotor 2. The inner wall portion 6n is formed as an arc surface along the outer circumferential surface of the disc rotor 2, and the inner end surface 6p in the disc radial direction is located radially inward from the outer end 6q of the large diameter cylinder bore 6h in the disc radial direction. A pad spring 11 is attached to the disc entry side end of the inner wall portion 6n, and the pad spring 11 contacts the suspension piece 7d and projection 7e of the friction pad 7 to suppress rattle of the friction pad 7. The inner end surface 6p in the disc radial direction has a recess 6r to avoid contact with the outer end 6q of the large diameter cylinder bore 6h in the disc radial direction, and a recess 6s to avoid contact with the pad spring 11.

[0025] In the disc brake 1 constructed as described above, when pressurized working fluid is supplied to the cylinder bores 6h and 6i during braking, the pistons 9 and 10 move toward the cylinder bore opening, pushing the friction pad 7 on the working side toward the disc rotor 2, and pressing the lining 7a of the friction pad 7 against one side of the disc rotor 2. Due to this reaction force, the caliper body 6 moves toward the working side guided by the slide pins 4 and 5, and the disc entry side reaction force claw 6m, the intermediate reaction force claw 6k, and the disc exit side reaction force claw 6j push the friction pad 7 on the reaction side toward the disc rotor 2, and pressing the lining 7a of the friction pad 7 against the other side of the disc rotor 2.

[0026] In this case, the caliper body 6 is provided with an outgoing rib portion 21, an intermediate rib portion 23, and an ingoing rib portion 22, thereby ensuring rigidity and preventing deformation of the caliper body 6. Furthermore, since the width of the second rib portion 23b in the circumferential direction of the disc is kept to the minimum necessary width, the weight of the caliper body 6 can be reduced while maintaining rigidity.

[0027] Furthermore, since the inner end face 6p of the bridge portion 6c is located radially inward of the outer end 6q of the large-diameter cylinder bore 6h in the disc radial direction, the thickness of the inner wall portion 6n in the disc radial direction can be increased toward the inside in the disc radial direction, thereby increasing the rigidity of the caliper body 6 without increasing the size of the caliper body 6.

[0028] When the diameters of the cylinder bores are different, the side with the larger diameter cylinder bore is generally where the stress generated by the force directed toward the axial bottom of the cylinder bore is greater, as in the example configuration described above. However, depending on the position of the union bore and bleeder boss, and the position of the vehicle body mounting arm, the side with the smaller diameter cylinder bore may also experience greater stress. In this case, the rib centerline CL1 can be offset towards the side with the smaller diameter cylinder bore.

[0029] Furthermore, when the rib center line CL1 passing through the center of the disc circumferential direction of the second rib portion 23b and the reaction claw center line CL2 passing through the center of the disc circumferential direction of the intermediate reaction claw 6k formed between adjacent cylinder holes are virtually placed on the same line, the bridge portion 6c is formed with the rib center line CL1 offset from the reaction claw center line CL2 in one direction of the disc circumferential direction (the area D shown in Figure 3) where the stress generated by the force directed toward the bottom side of the cylinder hole in the central axis direction of the bridge portion 6c is large, and the third rib portion 23c is formed by connecting the second rib portion 23b and the intermediate reaction claw 6k, the rigidity of the caliper body 6 can be increased without increasing the size of the caliper body 6.

[0030] Furthermore, the number and diameter of the cylinder bores in the caliper body of the present invention are arbitrary. When there are three or more cylinder bores and multiple intermediate rib sections are formed between adjacent cylinder bores, if the rib centerline of each intermediate rib section and the reaction claw centerline of each intermediate reaction claw are virtually placed on the same line, the rib centerline should be offset from the reaction claw centerline on the side of the cylinder bore where the stress generated by the force directed toward the axial bottom of the cylinder bore is greater, in relation to the adjacent cylinder bores.

[0031] Furthermore, while the above description compares the magnitude of stress generated by forces directed toward the axial bottom of the cylinder bore with the cylinder bore as the reference, the present invention is not limited to this. It is also possible to compare the magnitude of stress generated on the disc entry side and the disc exit side of the bridge portion with the bridge portion as the reference.

[0032] 1...Disc brake, 2...Disc rotor, 3...Caliper bracket, 3a...Plate-shaped part, 3b...Pad support arm, 3c...Pad guide groove, 4, 5...Slide pin, 6...Caliper body, 6a...Acting part, 6b...Reaction part, 6c...Bridge part, 6d, 6e...Body mounting arms, 6f, 6g...Hanger pin support arms, 6h, 6i...Cylinder bore, 6j...Disc recovery side reaction claw, 6k...Intermediate reaction claw, 6m...Disc return side reaction claw, 6n...Inner wall part, 6p...Disc half Radial inner end face, 6q...Disk radial outer end, 6r, 6s...Recess, 6t...Disk entry side, 7...Friction pad, 7a...Lining, 7b...Backing plate, 7c...Ear piece, 7d...Suspension piece, 8...Hanger pin, 9, 10...Piston, 11...Pad spring, 12a...Union hole, 12b...Bleeder boss, 13...Bleeder, 21...Exit side rib, 22...Entry side rib, 23...Intermediate rib, 23a...First rib, 23b...Second rib, 23c...Third rib

Claims

1. A disc brake comprising a caliper body having an action part located on one side of a disc rotor and having a plurality of cylinder boreholes for housing pistons, and a reaction part located on the other side of the disc rotor and having reaction claws, connected by a bridge portion, and a rib portion formed extending across the action part, the bridge portion and the reaction part, wherein the rib portion is formed between adjacent cylinder boreholes and comprises a first rib portion formed on the action part, a second rib portion formed on the bridge portion and a third rib portion formed on the reaction part in a series, wherein the second rib portion is formed such that, when the rib center line passing through the center of the disc circumferential direction of the second rib portion and the reaction claw center line passing through the center of the disc circumferential direction of the intermediate reaction claw formed between the adjacent cylinder boreholes are virtually placed on the same line, the rib center line is offset from the reaction claw center line on the side of the adjacent cylinder bore that has a larger stress due to the force directed toward the axial bottom side of the cylinder bore, The disc brake is characterized in that the third rib portion is formed by connecting the second rib portion and the intermediate reaction claw.

2. A disc brake comprising a caliper body having an action portion located on one side of a disc rotor and having a plurality of cylinder bores for housing pistons, and a reaction portion located on the other side of the disc rotor and having reaction claws, connected by a bridge portion, and a rib portion formed extending across the action portion, the bridge portion and the reaction portion, wherein the rib portion is formed between adjacent cylinder bores and comprises a first rib portion formed on the action portion, a second rib portion formed on the bridge portion and a third rib portion formed on the reaction portion in a series, The disc brake is characterized in that, when the rib center line passing through the center of the disc circumferential direction of the second rib portion and the reaction claw center line passing through the center of the disc circumferential direction of the intermediate reaction claw formed between adjacent cylinder holes are virtually placed on the same line, the bridge portion is formed with the rib center line offset from the reaction claw center line in one direction of the disc circumferential direction where the stress generated by the force directed toward the bottom side of the cylinder hole in the central axis direction is large, and the third rib portion is formed connecting the second rib portion and the intermediate reaction claw.

3. The disc brake according to claim 1 or 2, characterized in that the intermediate reaction claw is provided such that the center line of the reaction claw is offset over the second rib portion.

4. The disc brake according to claim 1 or 2, characterized in that the caliper body is provided with an outward-side rib portion extending from the acting portion, the bridge portion, and the reaction portion on the outward-side in the direction of disc rotation, and an inward-side rib portion extending from the acting portion, the bridge portion, and the reaction portion on the inward-side in the direction of disc rotation.

5. The disc brake according to claim 1 or 2, characterized in that the bridge portion has an inner wall portion on the radially inward side of the disc, and the radially inward end face of the inner wall portion is provided further inward in the disc radial direction than the radially outward end of at least one cylinder bore.

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