Caliper body of disc brake

Abstract

To suppress partial wear of a friction pad using a structure of a fluid passage for supplying working fluid.SOLUTION: A disc turn-out side cylinder hole 3d and a disc turn-in side cylinder hole 3e are formed in a pair of action parts 3a, 3b, respectively, and adjacent disc turn-out side cylinder holes 3d and disc turn-in side cylinder 3e in a disc circumferential direction are connected by liquid passages 21, 22. Further, an inter-action part liquid passage 23 is provided which connects the disc turn-in side cylinder hole 3e of one action part 3a with the disc turn-out side cylinder hole 3d of the other action part 3b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a caliper body for a disc brake, and more particularly to a caliper body for a disc brake having a pair of operating parts arranged on either side of a disc rotor, each of which has a cylinder hole on the disc rotation exit side and the disc rotation entry side when the vehicle is moving forward. [Background technology]

[0002] Conventionally, in caliper bodies in which a pair of working parts arranged on either side of the disc rotor are connected by a bridge part spanning the outer periphery of the disc rotor, and each working part has a disc rotation-out side cylinder hole on the disc rotation-out side and a disc rotation-in side cylinder hole on the disc rotation-in side, for example, there are formed liquid passages that connect the union hole provided on the disc rotation-out side with the disc rotation-out side cylinder holes of both working parts, and liquid passages that connect adjacent cylinder holes in the disc circumferential direction, and working fluid is supplied to each cylinder hole through these liquid passages (see, for example, Patent Document 1).

[0003] In addition, there was a caliper body provided with a connecting pipe that connects the disc rotation side cylinder holes of both acting parts, and a liquid passage that connects adjacent cylinder holes in the disc circumferential direction, and hydraulic fluid is supplied to each cylinder hole from a union hole provided in the liquid passage of one of the acting parts via the connecting pipe and liquid passage (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 2554958 [Patent Document 2] Patent No. 5084753 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned patent documents, the fluid passages and connecting pipes can be formed in the caliper body in a rational manner in that they connect adjacent locations, but if braking is performed by supplying hydraulic fluid to each cylinder hole through fluid passages and connecting pipes of this structure, there is a risk that the self-servo effect that occurs during braking will cause excessive wear on the inlet side of the disc, resulting in uneven wear.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a caliper body for a disc brake that suppresses uneven wear of the friction pads by using a fluid passage structure that supplies hydraulic fluid. [Means for solving the problem]

[0007] In order to achieve the above object, the caliper body of the disc brake of the present invention is characterized in that adjacent cylinder holes in the disc circumferential direction of each acting part are connected by a fluid passage, the disc rotation-in side cylinder hole of one acting part is connected to the disc rotation-out side cylinder hole of the other acting part by a fluid passage between the acting parts, and the union hole is connected to the disc rotation-out side cylinder hole of one acting part. [Effects of the Invention]

[0008] According to the disc brake caliper body of the present invention, during braking, hydraulic fluid is first supplied to the disc rotation-side cylinder bore of one of the acting parts through the union bore, then the hydraulic fluid is sequentially supplied to the cylinder bores toward the disc rotation-side cylinder bore of one of the acting parts through the fluid passage, further, hydraulic fluid is supplied from the disc rotation-side cylinder bore of one acting part through the inter-acting part fluid passage toward the disc rotation-side cylinder bore of the other acting part, then the hydraulic fluid is sequentially supplied to the cylinder bores toward the disc rotation-side cylinder bore of the other acting part through the fluid passage.

[0009] As a result, in each operating section, the piston on the disc rotation side begins to operate toward the disc rotor at an earlier timing than the piston on the disc rotation side. As a result, the pistons generate a pressing force that presses the friction pad against the disc rotor in sequence from the disc rotation side to the disc rotation side, which suppresses excessive wear on the disc rotation side due to the self-servo effect, and prevents uneven wear of the friction pad. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic view of a fluid passage formed in a caliper body showing an embodiment of the present invention; [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2. [Figure 5] 1 is a front view of a caliper body showing an embodiment of the present invention. [Figure 6] FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1 to 7 are diagrams showing an example of a caliper body of a disc brake of the present invention. Note that arrow A indicates the rotation direction of the disc rotor that rotates together with the wheel when the vehicle is moving forward, and the disc rotation outgoing side and disc rotation incoming side described below refer to the direction when the vehicle is moving forward.

[0012] The disc brake 1 includes a caliper body 3 arranged across the outer periphery of a disc rotor 2, and a pair of friction pads 4, 4 arranged on either side of the disc rotor 2. The caliper body 3 is formed into a monocoque structure that integrally includes a pair of acting portions 3a, 3b arranged opposite each other with the disc rotor 2 in between, and a bridge portion 3c that connects the pair of acting portions 3a, 3b across the outer periphery of the disc rotor 2.

[0013] A pair of mounting boss portions 3f, 3f are provided in the radial direction of the disk on the disk rotation exit side and disk rotation entry side of one of the action portions 3a, and each mounting boss portion 3f has a mounting hole 3g formed therein through which a mounting bolt (not shown) is inserted, and the caliper body 3 is connected to the vehicle body by the mounting bolt inserted into the mounting hole 3g.

[0014] Each of the operating portions 3a, 3b is provided with a disk rotation-side cylinder hole 3d and a disk rotation-side cylinder hole 3e, which are open on the disk rotor 2 side, facing each other. The disk rotation-side cylinder hole 3d is formed with a larger diameter than the disk rotation-side cylinder hole 3e, and a large-diameter piston 5 is inserted into the disk rotation-side cylinder hole 3d. A piston seal 5a is interposed between the disk rotation-side cylinder hole 3d and the outer peripheral surface of the piston 5, and the piston seal 5a makes liquid-tight and movable sliding contact with the outer peripheral surface of the piston 5, and rolls back the piston 5 with its restoring force. A small-diameter piston 6 is inserted into the disk rotation-side cylinder hole 3e. A piston seal 6a is interposed between the disk rotation-side cylinder hole 3e and the outer peripheral surface of the piston 6, and the piston seal 6a makes liquid-tight and movable sliding contact with the outer peripheral surface of the piston 6, and rolls back the piston 6 with its restoring force.

[0015] In one of the action parts 3a, a hydraulic pressure chamber 7 to which hydraulic fluid is supplied is provided between the disc rotation-side cylinder hole 3d and the piston 5, and a hydraulic pressure chamber 8 is provided between the disc rotation-side cylinder hole 3e and the piston 6. Similarly, in the other action part 3b, a hydraulic pressure chamber 9 is provided between the disc rotation-side cylinder hole 3d and the piston 5, and a hydraulic pressure chamber 10 is provided between the disc rotation-side cylinder hole 3e and the piston 6.

[0016] 1, one of the action parts 3a is formed with a fluid passage 21 that connects the disk rotation-side cylinder bore 3d and the disk rotation-side cylinder bore 3e, which are adjacent in the disk circumferential direction, and the fluid pressure chambers 7 and 8 are connected by this fluid passage 21. The other action part 3b, like the one action part 3a, is formed with a fluid passage 22 that connects the disk rotation-side cylinder bore 3d and the disk rotation-side cylinder bore 3e, which are adjacent in the disk circumferential direction, and the fluid passage 22 connects the fluid pressure chambers 9 and 10. Furthermore, an inter-action part fluid passage 23 is formed that connects the disk rotation-side cylinder bore 3e of one action part 3a with the disk rotation-side cylinder bore 3d of the other action part 3b, and the inter-action part fluid passage 23 connects the fluid pressure chambers 8 and 9, which are provided on either side of the disk rotor 2.

[0017] One of the action parts 3a is provided with a union hole 11 that communicates with the disc rotation side cylinder hole 3d and supplies hydraulic fluid to the hydraulic chamber 7. Furthermore, one of the action parts 3a is provided with a bleeder hole 12 that communicates with the disc rotation side cylinder hole 3d of the other action part 3b and that discharges air from the hydraulic fluid.

[0018] As shown in Figure 2, the bridge portion 3c is provided on the disc rotation side and includes a disc rotation side bridge portion 3h in which a bleeder hole 12 is formed, a disc rotation side bridge portion 3i in which a disc rotation side bridge portion 3i is provided on the disc rotation side, and an intermediate bridge portion 3j in which an inter-action portion liquid passage 23 is formed and which is provided between the disc rotation side bridge portion 3h and the disc rotation side bridge portion 3i.

[0019] A first ceiling opening 3k is formed between the intermediate bridge portion 3j and the disc entrance bridge portion 3i. Furthermore, three second ceiling openings 3m are formed in three locations on the intermediate bridge portion 3j located on the outer periphery of the disc between the pair of friction pads 4, 4, and braking heat is released to the outside through the first ceiling opening 3k and the three second ceiling openings 3m.

[0020] The friction pad 4 is made up of a lining 4a and a back plate 4b, and is provided so as to be movable in the axial direction of the disk.

[0021] Next, a method for forming the liquid passages 21 and 22 and the inter-action portion liquid passage 23 will be described with reference to FIG.

[0022] The fluid passage 21 is formed by inserting a cutting tool through the union hole 11 and cutting between the disc rotation-side cylinder bore 3d and the disc rotation-side cylinder bore 3e of one of the acting parts 3a. The fluid passage 22 is formed by inserting a cutting tool through a first tool insertion part 22a formed on the disc rotor rotation side of the other acting part 3b and cutting between the disc rotation-side cylinder bore 3d and the disc rotation-side cylinder bore 3e of the other acting part 3b. The bleeder hole 12 is in communication with the hydraulic chamber 9 via a machined hole 22b formed by inserting a cutting tool through the first tool insertion part 22a.

[0023] The inter-action-unit liquid passage 23 is formed by inserting a cutting tool through a second tool insertion portion 23a formed at the outer end of the intermediate bridge portion 3j to form a first machined hole 23b cut toward the disk rotation-side cylinder bore 3e of one of the action portions 3a, and by inserting a cutting tool through a third tool insertion portion 23c formed at the outer end of the intermediate bridge portion 3j to form a second machined hole 23d cut toward the disk rotation-side cylinder bore 3d of the other action portion 3b, at an intersection P1. In addition, the openings of the first tool insertion portion 22a, the second tool insertion portion 23a, and the third tool insertion portion 23c are sealed with a sealing member (not shown) after the liquid passage 22 and the inter-action-unit liquid passage 23 are cut.

[0024] In the disc brake 1 configured as described above, as shown in Figure 1, during braking, hydraulic fluid is first supplied to hydraulic chamber 7 on the disc rotation side of one of the acting portions 3a via union hole 11, and then to hydraulic chamber 8 on the disc rotation side of one of the acting portions 3a via hydraulic passage 21 (arrow B1). Next, hydraulic fluid is supplied from hydraulic chamber 8 to hydraulic chamber 9 on the disc rotation side of the other acting portion 3b via inter-acting portion hydraulic passage 23 (arrow B2). Furthermore, hydraulic fluid is supplied from hydraulic chamber 9 to hydraulic chamber 10 on the disc rotation side of the other acting portion 3b via hydraulic passage 22 (arrow B3).

[0025] Due to this flow of hydraulic fluid, the large-diameter piston 5 on the disc rotation side of one of the action parts 3a begins to operate first, followed by the small-diameter piston 6 on the disc rotation side of one of the action parts 3a, and then the large-diameter piston 5 on the disc rotation side of the other action part 3b, and finally the small-diameter piston 6 of the other action part 3b begins to operate.

[0026] In this way, in each acting portion 3a, 3b, the pistons 5, 5 on the disc rotation side start to operate toward the disc rotor 2 at an earlier timing than the pistons 6, 6 on the disc rotation side. Accordingly, at the initial stage of braking, the pressing force with which the pistons 5, 5, 6, 6 press the friction pads 4, 4 against the disc rotor 2 is higher on the disc rotation side than on the disc rotation side.

[0027] Furthermore, because the disc rotation-side cylinder bore 3d is formed with a larger diameter than the disc rotation-side cylinder bore 3e, the flow path cross-sectional area of ​​the hydraulic chambers 7, 9 is larger than the flow path cross-sectional area of ​​the hydraulic chambers 8, 10. Accordingly, at the initial stage of braking, the pressing force of the pistons 5, 5 is higher than the pressing force of the pistons 6, 6, and the pressing force with which the pistons 5, 5, 6, 6 press the friction pads 4, 4 against the disc rotor 2 is higher on the disc rotation-side than on the disc rotation-in side. Furthermore, because the piston 6 on the disc rotation-in side of the other acting portion 3b begins to operate toward the disc rotor 2 at the latest timing, the pressing force on the disc rotation-in side can be reduced.

[0028] As described above, the pressing force by each piston 5, 5, 6, 6 pressing the friction pads 4, 4 against the disc rotor 2 is higher on the disc rotation side of the friction pads 4, 4 than on the disc rotation side of the friction pads 4, 4 at the beginning of braking, and by generating the pressing force pressing the friction pads 4, 4 against the disc rotor 2 sequentially from the disc rotation side to the disc rotation side, a self-servo effect can be achieved to prevent excessive wear on the disc rotation side of the friction pads 4, 4. In addition, since uneven wear of the friction pads 4 can be suppressed, the durability of the friction pads 4 can be improved. Furthermore, by suppressing uneven wear of the friction pads 4, drag of the friction pads 4 can be reduced, and changes in operating feel due to use can also be reduced.

[0029] In addition, since the caliper body 3 has a monocoque structure, it is lightweight and highly rigid, and furthermore, by forming the liquid passage 23 between the acting parts in the intermediate bridge part 3j, it is possible to form the liquid passage 23 between the acting parts without increasing the number of parts.

[0030] The present invention is not limited to the above-described embodiment in which each operating portion has two cylinder holes, but can also be applied to a configuration in which each operating portion has three or more cylinder holes, with adjacent cylinder holes connected circumferentially to the disk by a fluid passage. Furthermore, in a configuration in which each operating portion has three or more cylinder holes, the diameters of the cylinder holes may be gradually reduced from the disk exit cylinder hole toward the disk entry cylinder hole. Furthermore, the diameter of the cylinder holes formed between the disk exit cylinder hole and the disk entry cylinder hole is optional, and they may be formed to the same diameter. Furthermore, the caliper body is not limited to a monocoque structure, and may be a split-type caliper body. [Explanation of symbols]

[0031] 1...disc brake, 2...disc rotor, 3...caliper body, 3a, 3b...action portion, 3c...bridge portion, 3d...disc rotation exit side cylinder hole, 3e...disc rotation entry side cylinder hole, 3f...mounting boss portion, 3g...mounting hole, 3h...disc rotation exit side bridge portion, 3i...disc rotation entry side bridge portion, 3j...intermediate bridge portion, 3k...first ceiling opening, 3m...second ceiling opening, 4...friction pad, 4a...lining, 4b...back plate, 5, 6...piston, 5a, 6a...piston seal, 7, 8, 9, 10...hydraulic pressure chamber, 11...union hole, 12...bleeder hole, 21, 22...fluid passage, 22a...first tool insertion portion, 22b...machined hole, 23...fluid passage between action portions, 23a...second tool insertion portion, 23b...first machined hole, 23c...third tool insertion portion, 23d...second machined hole

Claims

1. A disc brake caliper body in which a pair of working portions arranged on either side of a disc rotor are connected by a bridge portion that straddles the outer periphery of the disc rotor, a plurality of cylinder holes are provided facing each other in the pair of working portions, and adjacent cylinder holes in the disc circumferential direction are communicated with each other by a fluid passage, a fluid passage between the operating portions that communicates a disc rotation-in side cylinder hole that is arranged on the most disc rotation-in side of one of the operating portions when the vehicle is moving forward and a disc rotation-out side cylinder hole that is arranged on the most disc rotation-out side of the other operating portion when the vehicle is moving forward; A disc brake caliper body characterized in that a union hole for supplying hydraulic fluid is connected to a disc rotation side cylinder hole of one of the acting parts, which is located on the disc rotation side closest to the disc rotation side when the vehicle is moving forward.

2. 2. The disc brake caliper body according to claim 1, wherein one of the action portions has a mounting hole through which a mounting bolt is inserted, and the caliper body is connected to the vehicle body by the mounting bolt inserted into the mounting hole.

3. 2. The caliper body for a disc brake according to claim 1, wherein the cylinder holes are formed so that their diameters gradually decrease from the disc rotation-side cylinder hole toward the disc rotation-side cylinder hole.

4. 2. The caliper body for a disc brake according to claim 1, wherein the disc rotation-side cylinder hole is formed to have a larger diameter than the disc rotation-side cylinder hole.

5. 5. A disc brake caliper body according to claim 1, wherein the caliper body has a monocoque structure in which a pair of the action portions and the bridge portion are integrally formed, and the liquid passage between the action portions is formed in the bridge portion.

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