JP2007231984A - Disk brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately maintain a clearance between a rotor and pads and to reduce noise caused by a slide pin. <P>SOLUTION: The disk brake includes: a disk rotor which rotates together with a wheel; the brake pads arranged facing friction sliding surfaces of the disk rotor; a caliper provided with one of a guile hole and the slide pin which are slidably fitted to each other; and a mounting provided with the other of the guide hole and the slide pin and supporting the caliper. A top end of the slide pin on the side to be fitted in the guide hole is received in a case body. An elastic member is made to adhere to the case body and is inserted into the guide hole with an interference. A spring member for urging the slide pin 22 toward the innermost side of the case body is installed in the case body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disc brake, and more particularly, to a technique for maintaining a proper posture of a slide pin.

  In general, a disc brake mainly includes a caliper, a disc rotor, and a brake pad. The caliper has a cylinder portion and a claw portion, and the brake pad is disposed between the cylinder portion and the claw portion with the disc rotor interposed therebetween.

  The mounting fixed to the non-rotating part of the vehicle has a pair of left and right support arms spaced along the circumferential direction of the disk. Each support arm is provided with a guide hole. A slide pin is slidably inserted into the guide hole, and the slide pin is fixed to the caliper by a bolt. When the caliper moves toward the disc rotor by sliding between the guide hole and the slide pin, the disc rotor is clamped by the pair of brake pads to brake the wheel.

In the disc brake structure, the cylinder posture may not be properly maintained due to the weight of the cylinder portion. For this reason, the pad and the rotor may come close to each other and come into contact with each other, causing dragging.
Patent Document 1 discloses that as a technique for preventing dragging, a slide pin is provided with an annular groove, and a pin bush with an elastic protrusion is brought into close contact with the annular groove. The pin bush with the elastic protrusion serves to keep the cylinder posture properly.
Japanese Utility Model Publication No. 7-19629

  When the brake pad is dragged by the rotor, an abnormal noise is generated and uneven wear occurs. Therefore, development of a structure that can effectively prevent dragging is desired.

  An object of the present invention is to provide a technique for appropriately maintaining a cylinder posture.

  One embodiment of the present invention relates to a disc brake. This disc brake is provided with one of a disc rotor that rotates together with the wheels, a brake pad that is disposed to face the frictional sliding surface of the disc rotor, and a guide hole and a slide pin that are slidably inserted into each other. A caliper and a mounting for supporting the caliper by providing the other of the guide hole and the slide pin are provided. The disc brake includes a case body that houses the tip of the slide pin that is inserted into the guide hole, and a case body that is fixed to the outside of the case body and closely contacts the guide hole. It further includes an elastic body that is held at a predetermined position inside.

  According to this aspect, the case body that accommodates the tip end of the slide pin that is fitted into the guide hole is held in the guide hole by the elastic body at a predetermined position. The movement can be suppressed and the occurrence of drag can be avoided.

  A spring member that biases the slide pin toward the back of the guide hole is preferably provided inside the case body. By urging the slide pin toward the back of the guide hole, drag can be further suppressed.

  According to the disc brake of the present invention, since the posture of the slide pin can be directly maintained, dragging can be suppressed. Further, it is possible to suppress the generation of noise due to the slide pin coming into contact with the guide hole.

  In this embodiment, the mechanism of the slide pin of the present invention will be described using a floating caliper.

FIG. 1 shows a floating caliper type disc brake 10 according to an embodiment of the present invention.
The disc brake 10 includes a mounting 12 fixed to a non-rotating member of a vehicle (not shown), and a caliper 16 that is slidably supported by the mounting 12. The caliper 16 includes a cylinder portion 58 having a piston 46 therein, and a claw portion 56 that extends from the cylinder portion 58 and faces the cylinder portion 58 with the disk rotor 26 interposed therebetween. An inner brake pad 32 and an outer brake pad 42 (also referred to as “brake pad” together) are opposed to each other between the cylinder portion 58 and the claw portion 56 with the disc rotor 26 rotating coaxially with the wheels. It is arranged. Back metal components 30 and 40 are attached to the sides of the inner brake pad 32 and the outer brake pad 42 that do not face the disc rotor 26, respectively. The backing metal structure 30 is supported on the inner side of the disk rotor 26 by the mounting 12 so as to be slidable in the axial direction of the disk rotor 26. Further, the back metal structure 40 is supported by the mounting 12 so as to be slidable in the axial direction of the disk rotor 26 on the outer side of the disk rotor 26.

  The piston 46 of the caliper 16 described above is disposed on the back portion of the back metal component 30. When the piston 46 is actuated to push the back metal component 30, the inner brake pad 32 is pushed toward the inner side of the disk rotor 26 (in the direction of the arrow 70 shown in FIG. 1). Further, a claw portion 56 of the caliper 16 is disposed on the back portion of the back metal structure 40. When the claw portion 56 moves and presses the back metal structure 40, the outer brake pad 42 is pressed toward the outer side of the disk rotor 26 (in the direction of the arrow 71 shown in FIG. 1).

  The mounting 12 includes a pair of arm portions 14 in which guide holes 20 parallel to each other are formed. The caliper 16 includes a pair of caliper arms 18 extending from the cylinder portion 58 in the circumferential direction of the disk rotor 26. The caliper arm 18 is formed with pin bolt holes 44 parallel to each other for bolting the slide pin 22 to the caliper arm 18. In the axial direction of the disc rotor 26, the slide pins 22 are fixed by pin bolts 24, respectively. The slide pin 22 is longer than the depth of the guide hole 20. The slide pin 22 is slidably inserted into the guide hole 20 with a predetermined gap. Accordingly, the caliper 16 is supported by the mounting 12 in a state where the slide pin 22 and the guide hole 20 are slidable in the axial direction of the disk rotor 26.

  A cylindrical pin boot (also called a dust boot) 50 made of a flexible member such as rubber is attached between the base of the slide pin 22 and the opening end of the guide hole 20 of the arm portion 14. An annular groove 64 is formed on the inner peripheral surface of the opening end of the guide hole 20, and an attachment portion 52 at one end of the pin boot 50 is fitted into the annular groove 64 with a tightening margin with the slide pin 22. Yes. An annular groove 66 is also formed on the outer periphery of the base portion of the slide pin 22, and a mounting portion 62 at the other end of the pin boot 50 is fitted in the annular groove 66. The bellows-shaped annular connecting portion 60 that connects the mounting portion 52 on the guide hole side and the mounting portion 62 on the slide pin side is thinner than both mounting portions, and follows the sliding displacement of the slide pin 22. It is designed to expand and contract. The annular connecting portion 60 covers the sliding surfaces of the slide pin 22 and the guide hole 20 and prevents foreign matters such as dust and dirt from entering the sliding surface.

  In the disc brake 10 according to the present embodiment, a drag avoidance structure 100 is provided at the tip of the slide pin 22 on the side inserted into the guide hole in order to avoid drag. The drag avoiding structure 100 plays a role of maintaining a proper cylinder posture and avoiding drag.

FIG. 2 is a cross-sectional view of the disc brake 10 shown in FIG.
The piston 46 is connected to the back surface of the back metal structure 30, that is, the side not attached to the inner brake pad 32. Further, a pressing surface 74 is formed at the tip of the claw portion 56 so as to come into contact with the back surface of the back metal component 40 in a plane. The piston seal 28 serves to maintain an appropriate clearance between the inner brake pad 32 and the rotor 26.

  When shifting from the non-braking state to the braking state, when the piston 46 protrudes in the direction of the disk rotor 26 (the direction of the arrow 70) by the hydraulic pressure supplied from the outside, the inner brake pad 32 moves to the inner side of the disk rotor 26. Pressed against. The reaction force causes the caliper 16 to move in the direction opposite to the direction in which the piston 46 protrudes (the direction of the arrow 71). The outer brake pad 42 is pressed against the outer side of the disk rotor 26 by the pressing surface 74 of the claw portion 56. As the caliper 16 moves, the slide pin 22 slides toward the opening end of the guide hole 20 (in the direction of the arrow 71 in FIG. 1). As a result, the disc rotor 26 is pinched by the inner brake pad 32 and the outer brake pad 42, and the wheels are braked.

  When shifting from the braking state to the non-braking state, the piston seal 28 controls the retraction amount of the piston 46 (the amount of movement in the direction of the arrow 71) to be constant. Therefore, even if the inner brake pad 32 is worn, the clearance between the inner brake pad 32 and the disc rotor 26 is constant during non-braking. The slide pin 22 moves in the direction of the arrow 71 in FIG. 1 according to the amount of wear of the inner brake pad 32.

FIG. 3 is a diagram illustrating the appearance of the piston 46 and the piston seal 28 during non-braking or during braking.
FIG. 3A shows a state at the time of non-braking. At the time of non-braking, the piston seal 28 is not bent. The piston seal 28 and the seal groove 29 are bonded, and the piston seal 28 and the piston 46 are not bonded.
FIG. 3B shows a state during braking. When shifting from the non-braking state to the braking state, the piston 46 moves in the direction of the arrow 70. Due to the sliding resistance between the piston 46 and the piston seal 28, the piston seal 28 is refracted as shown in the figure.
Here, even when the amount of movement of the piston 46 in the direction of the arrow 70 increases due to wear of the inner brake pad 32, the piston seal 28 is bonded to the seal groove 29. It refracts only to the limit point.

In the process of changing from the braking state to the non-braking state, the piston seal 28 attempts to return to the state of the piston seal 28 in FIG. Along with this, the piston 46 also moves backward in the direction of the arrow 71.
The retraction amount of the piston 46 is constant in the process in which the piston seal 28 is refracted to a predetermined limit point and then enters the non-braking state. This is because the retraction amount of the piston 46 is determined by the degree of refraction of the piston seal 28. Therefore, even if the inner brake pad 32 is worn, the clearance between the inner brake pad 32 and the disk rotor 26 is kept constant.

FIG. 4 is a diagram showing the drag avoidance structure 100.
The drag avoidance structure 100 includes a case body 25, an elastic body 23, and a spring member 27.
The case body 25 accommodates inside the tip of the slide pin 22 which is inserted into the guide hole 20, and prevents noise caused by contact of the accommodated tip with the guide hole. The case body is a cylindrical member and has a space inside. An elastic body 23 is fixed to the side wall of the case body 25. The elastic body 23 is an annular member, and its inner peripheral surface is bonded and fixed to the side wall of the case body 25 and is inserted into the guide hole 20 with an interference. The elastic body 23 serves to hold the case body 25 at a predetermined position inside the guide hole 20. The spring member 27 is provided inside the case body 25. The spring member 27 urges the slide pin 22 toward the back of the guide hole 20, that is, in the direction of the arrow 70, and prevents the slide pin 22 from moving in the direction of the arrow 71 due to the weight of the cylinder portion 58. Thereby, it plays the role which prevents dragging.

  The elastic body 23 is in frictional contact with the side wall of the guide hole 20 so that the elastic body 23 does not move due to the weight of the cylinder portion 58, and holds the case body 25 at a predetermined position of the guide hole 20. The degree of frictional contact is set to be weaker than the force by which the caliper 16 protrudes in the direction of the arrow 71 by hydraulic pressure. Therefore, the elastic body 23 moves in the direction of the arrow 71 little by little according to the degree of wear of the brake pad.

  As the elastic body 23 moves, the case body 25 and the slide pin 22 move in the direction of the arrow 71. By linking the elastic body 23 and the piston seal 28, even when the inner brake pad 32 is worn, the clearance during non-braking between the inner brake pad 32 and the disk rotor 26 can be maintained constant. Thereby, dragging is prevented.

  When the brake pad is not worn during the brake operation, the slide member 22 slides due to the spring member 27 contracting, and the elastic body 23 does not move. On the other hand, when it wears, the elastic body 23 shifts according to the amount of wear.

  According to the structure of this embodiment, the member for maintaining the clearance between a brake pad and a rotor appropriately, and the member for maintaining a cylinder attitude | position appropriately can be separated. Therefore, the slidability between the slide pin and the guide hole can be improved.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

  In the embodiment, the caliper having one piston has been described. However, the present invention can also be applied to a double piston type caliper having two pistons.

It is a figure which shows a floating caliper type disc brake. It is sectional drawing of a disc brake. (A) is a figure which shows the mode of the piston and piston seal at the time of non-braking. (B) is a figure which shows the mode of the piston and piston seal at the time of braking. It is a figure which shows the drag avoidance structure.

Explanation of symbols

  10 disc brake, 12 mounting, 14 arm portion, 16 caliper, 18 caliper arm, 20 guide hole, 22 slide pin, 23 elastic body, 25 case body, 26 disc rotor, 27 spring member, 28 piston seal, 29 seal groove, 32 Inner brake pad, 42 Outer brake pad, 44 Pin bolt hole, 46 Piston, 50 Pin boot, 52 Mounting part, 56 Claw part, 58 Cylinder part, 60 Ring connecting part, 62 Mounting part, 64 Ring groove, 66 Ring groove, 74 Press surface, 100 Drag avoidance structure.

Claims (2)

A disk rotor that rotates with the wheels;
A brake pad disposed relative to the friction sliding surface of the disk rotor;
A caliper provided with one of a guide hole and a slide pin that are slidably inserted into each other;
A mounting for supporting the caliper by providing the other of the guide hole and the slide pin;
A disc brake with
A case body that accommodates the tip of the slide pin on the side inserted into the guide hole;
An elastic body that holds the case body in a predetermined position inside the guide hole by being fixed to the outside of the case body and closely contacting the guide hole;
A disc brake comprising:   The disc brake according to claim 1, wherein a spring member that urges the slide pin toward the back of the guide hole is provided inside the case body.

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