JPH0960666A - Multi-pot opposed caliper body for vehicle disc brake - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To prevent as much as possible the generation of rubbing noise and uneven wear of a friction pad due to deformation of a caliper body during braking. The disc entry side of the lining is prevented as early as possible from uneven wear due to the leading action. SOLUTION: The rollback amount of the piston at the time of braking release in which the piston is pulled back in the hydraulic chamber direction by the restoring force of the angular seal is set to the piston 18 in the intermediate portion sandwiched between the pistons on the disk entry side and the exit side. , Set larger than the pistons on the disk entry and exit sides. Set the rollback amount of the piston on the disc feed side to be larger than the rollback amount of the piston on the disc feed side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caliper body of a disc brake used in various traveling vehicles such as motorcycles and automobiles. More specifically, the caliper body is a multi-pot opposed type having six or more pots, and a braking operation is performed. The present invention relates to a structure for preventing the friction pad from being dragged by the disc rotor when the brake is released.

[0002]

2. Description of the Related Art In a disc brake used in a vehicle such as a motorcycle, a large number of cylinder holes of a caliper body are provided so as to face each other in the circumferential direction of the disc to reduce the diameter of the disc rotor and improve the braking force. A pot facing type caliper body is known, and an example thereof is disclosed in Japanese Utility Model Laid-Open No. 2-65724.

This caliper body is a 6-pot facing type in which a pair of working portions provided on both sides of a disk rotor are provided with three sets of cylinder holes facing each other, and a piston is provided in each cylinder hole. It is housed in a liquid-tight and movable manner through a ring-shaped corner seal, and a hydraulic chamber is defined between each piston and the bottom wall of the cylinder hole.

When the driver performs a braking operation, the pressurized hydraulic fluid is introduced into the respective hydraulic chambers, and the pistons advance the cylinder holes toward the disc rotor while elastically deforming the corner seals, and the discs are rotated. The friction pads on both sides of the rotor are pushed, and the linings of the friction pads are brought into sliding contact with the side surfaces of the disk rotor to perform a braking action. When the braking operation is released, each piston rolls back toward the hydraulic chamber due to the restoring force of the elastically deformed corner seal, and a predetermined amount is applied between the side surface of the disc rotor and the lining of the friction pad. The braking gap is set.

[0005]

Such a multi-pot opposed type caliper body has a shape that is longer and narrower in the disc circumferential direction than one having a small number of pots, and is connected to the other side across the disc rotor. Although the support rigidity is high on the delivery side, the support rigidity is low on the intermediate part apart from the disc entry side and the delivery side, so that both action parts are affected by the reaction force from the piston and hydraulic fluid. As shown by the imaginary line 2, it bulges and deforms to the side opposite to the disc.

Therefore, when the action portion after releasing the braking returns from the imaginary line shape to the solid line shape, the rollback amount of the intermediate piston is offset by the deformation amount of the action portion, and the predetermined amount of the cylinder hole is obtained. It cannot be returned to the retracted position, and the piston in the middle part prevents the friction pad from separating from the disc rotor, and the lining of the friction pad is dragged to the rotating disc rotor to prevent uneven wear of the lining and rubbing noise. It was the cause.

The present invention has been made in view of the above circumstances, and a sliding pad of a friction pad due to a deformation of the caliper body at the time of braking, even though it is a caliper body of a multi-pot opposed type elongated in the disk circumferential direction. The main purpose is to prevent noise and uneven wear as much as possible, and at the same time, the so-called leading action in which the disc entry side of the friction pad is caught in the rotation direction of the disc rotor causes the disc entry side of the lining to be biased early. (EN) It is an object to provide a multi-pot opposed type caliper body for a disc brake for a vehicle, in which abrasion is prevented as much as possible.

[0008]

As a first invention for achieving the above-mentioned main object, a pair of operating portions are arranged opposite to each other on both sides of a disk rotor which rotates in one direction as a vehicle travels. 3 or more sets of cylinder holes facing each other across the disk rotor are arranged side by side in the circumferential direction of the disk in the action part of the disk. Each cylinder hole accommodates the piston in a liquid-tight and movable manner through an angular seal. In a multi-pot opposed type caliper body of a vehicle disc brake, which defines a hydraulic chamber between the cylinder wall and the bottom wall of the cylinder hole,
The amount of rollback of the piston when braking is released when the piston is pulled back in the direction of the hydraulic chamber by the restoring force of the angular seal, and the amount of disk rotation is set to the piston in the middle part sandwiched between the piston on the disk entry side and the piston on the exit side. The feature is that it is set larger than the pistons on the inlet and outlet sides.

As a second aspect of the present invention for attaining the other object proposed in the above, the rollback amount of the piston on the disc advancing side of the first invention is determined by the rollback amount of the piston on the disc advancing side. The feature is that it is set larger than the amount.

In order to set the rollback amount of the piston, the size of the space for deforming the corner seal, which has a triangular cross section and is continuously provided on the disc rotor side of the seal groove for the corner seal, the angle of the inclined surface, and the angle seal. There are adjustments such as the tightening allowance, the inner peripheral surface roughness of the square seal, and the outer peripheral surface roughness of the piston. By also setting a large value, when the action part, which had been deformed in the anti-disk direction in the center part, returns to its original position when the braking operation is released, the piston in the middle part will not The cylinder hole is returned toward the hydraulic chamber to the same extent as the side piston.

In the second aspect of the invention, the piston on the disc turn-in side, which has released the braking operation, retracts deeper in the hydraulic chamber direction than the piston on the disc turn-out side. Therefore, during braking operation, the piston on the disc feed-out side pushes the friction pad with the piston on the disc feed-in side first, and the leading action that occurs on the disc feed-in side of the friction pad is shortened. As a result, uneven wear of the lining is prevented as much as possible.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

The disc brake 1 is a caliper body 2
The acting portions 2c, 2d of the above are disposed opposite to both side portions of the disk rotor 3 which rotates integrally with traveling wheels (neither of which is shown) in the direction of arrow A as the vehicle travels.
6 sets of three cylinder holes 4, 4, 5, 5, 6, 6 facing each other with the disc rotor 3 sandwiched in parallel in the disc circumferential direction.
The pot-opposing type caliper body 2 cuts the center of a bridge portion 2e that straddles the outer side of the disc rotor 3 and connects the action portions 2c and 2d along the rotational direction of the disc rotor 3 to form the caliper halves 2a, The disc turn-in side and the disc turn-out side of 2b are integrally connected by screwing four long and short connecting bolts 7 and 8.

The caliper half 2a is provided with a bracket 2f for mounting the vehicle body and a union hole 9 for introducing the hydraulic fluid. The caliper body 2 is constructed by bolting the bracket 2f to the vehicle body. Fixed. On the disc rotor side of the action portions 2c and 2d, the pad mounting recess 2 is formed.
g, 2g are provided, and the pad mounting recesses 2g, 2g are provided.
In g, a pair of friction pads 10 and 10 including a lining 10a and a metal back plate 10b are provided so as to be movable in the disc axial direction.

Six cylinder holes 4, 4, 5, 5, 6, 6
The dust seal 12 in the seal groove 11 on the opening side,
Square seals 14, 14, 15, 1 in the seal groove 13 on the bottom side
5, 16 and 16 are fitted in correspondence with each other, and the pistons 17, 17, 1 having a cup shape are fitted in these cylinder holes 4 to 6.
8, 18, 19, 19 are corner seals 14-16, respectively.
Is inserted so as to be liquid-tight and movable via. Hydraulic chambers 20, 20, 21, 21, 22 and 22 are defined between the pistons 17 to 19 and the bottom walls of the cylinder holes 4 to 6, and the caliper halves 2a and 2b are arranged in the disk circumferential direction. Hydraulic chambers 20, 21 and 22 adjacent to each other are communicated with each other through liquid passage holes 23 and 23, and two hydraulic chambers 2 facing each other on the disc feeding side are provided.
The communication holes 2 and 22 are communicated with each other through communication holes 24 and 24 that are abutted on the disc-outgoing side of the caliper halves 2a and 2b, and the communication hole 24 on the caliper half 2a side is communicated with the union hole 9. There is.

A hydraulic master cylinder (not shown) is connected to the union hole 9 through a brake hose when the caliper body 2 is fixed to the vehicle body, and when the driver performs a braking operation, the hydraulic master cylinder is connected. The hydraulic fluid whose pressure has been increased by is introduced into the union hole 9 and, further, through the communication holes 24, 24 and the liquid communication hole 23, all the hydraulic chambers 20, 29, 21, 2,
The working fluid is filled in 1, 22, 22.

When the hydraulic chambers 20 to 22 are expanded by filling with hydraulic fluid, the pistons 17 to 19 elastically deform the corner seals 14 to 16 while moving the cylinder holes 4 to 6 in the disk rotor direction. To move both friction pads 10 and 10 to move the linings 10a and 10
The braking action is performed by sliding a on both sides of the disc rotor 3. During this braking, the braking reaction force from the pistons 17 to 19 and the hydraulic fluid acts on the action portions 2c and 2d, and these action portions 2c and 2d are located on the disc entry side having high support rigidity by the connecting bolts 7 and 8. Piston 17-
19, the deformation due to the reaction force of the hydraulic fluid is small, but the supporting rigidity of the connecting bolts 7 and 8 is low at the intermediate portion apart from the connecting bolts 7 and 8, so that the action portions 2c and 2d are the imaginary lines in FIG. As shown in Fig. 3, the disk bulges and deforms to the side opposite to the disk.

When the above-mentioned braking operation is released, the respective pistons 17 to 19 roll back the cylinder holes 4 to 6 toward the hydraulic chambers by the restoring force of the square seals 14 to 16 returning to the original shape. , The action portion 2 which has returned to a predetermined retracted position and has been bulged and deformed to the side opposite to the disc.
c and 2d return to the solid line shape of FIG.

The corner seals 14 to 16 are formed by elastic rings made of elastic rubber or soft synthetic resin.
Pistons 17 to 19 having a diameter slightly smaller than that of the cylinder holes 4 to 6
Have their own. Further, the space portion 13 is provided on the disc rotor side and the non-disc rotor side of each seal groove 13.
a and 13b are continuously provided by C chamfering, and the space portion 13a on the disc rotor side has a larger triangular section than the space portion 13b on the side opposite to the disc rotor. The corner seals 14 to 16 fitted in the seal groove 13 are the piston 1
When the brakes 7 to 19 move forward in the direction of the openings in the cylinder holes 4 to 6, most of the portions bent by the drag of the pistons 17 to 19 are bulged into the space 13a to allow the deformation. There is.

The rollback amounts of the pistons 17 to 19 which return to the hydraulic chambers by releasing the brake are as follows: intermediate pistons 18 and 18> pistons 17 and 17 on the disc feed-in side> pistons 19 and 19 on the disc feed-out side. They are set in order. That is, the action parts 2c, 2 which are largely deformed by the braking reaction force
The piston 18, 18 located in the middle of d
In consideration of the bending deformations of c and 2d, a larger rollback amount is set than that of the pistons 17, 17, 19, and 19 on the disc turn-in side and turn-out side, and the disc turn-on side that causes a leading effect during braking is set. In consideration of the entrainment due to the leading action, the pistons 17 and 17 are set to have a larger rollback amount than the pistons 19 and 19 on the disc feeding side.

The rollback amount of the pistons 17 to 19 is set by the size of the space portion 13a on the disk rotor side, the angle of the inclined surface 13c on the outer periphery of the space portion 13a, the tightening margins of the angle seals 14 to 16, and the angle seals. 14-16 hardness, inner peripheral surface roughness of square seals 14-16 and pistons 17-19
It is determined by the roughness of the outer peripheral surface and the like. With such a rollback amount setting, when the braking operation is released, the pistons 18, 18 in the intermediate portion are sufficiently pulled back in the cylinder hole 5 toward the hydraulic chamber, and Since the pistons 18 and 18 do not prevent the friction pads 10 and 10 from being separated from the side surfaces of the disc rotor 3, it is possible to prevent uneven wear of the lining 10a and generation of rubbing noise due to dragging of the disc rotor 3 as much as possible. Will be able to.

Further, the pistons 17 and 1 on the disk entry side
In No. 7, the roll-back amount is set larger than that of the pistons 19 on the disc feed-out side, so that the piston on the disc feed-in side retracts deeper in the hydraulic chamber direction than the piston on the disc feed-out side after releasing the braking. . Therefore, at the time of braking operation, the pistons 19 and 19 on the disc advancing side push the friction pads 10 and 10 with delay, and the pistons 17 and 17 on the disc advancing side push the discs of the friction pads 10 and 10. The leading action that occurs on the entry side is suppressed in a short time, and uneven wear of the linings 10a, 10a is prevented as much as possible.

Although the above embodiment has been described by applying the second invention, it is possible to implement only the first invention. Further, the present invention can be applied to a facing type caliper body having 8 or more pots, in addition to the facing type 6 pots of the embodiment.

[0024]

The multi-pot opposed type caliper body of the vehicular disc brake according to the present invention determines the rollback amount of the piston when the brake is released when the piston is pulled back toward the hydraulic chamber by the restoring force of the angular seal. By setting the piston in the middle part sandwiched between the pistons on the inlet and outlet sides to be larger than the pistons on the disk inlet and outlet sides, the intermediate piston after releasing the braking operation Since the holes can be sufficiently pulled back toward the hydraulic chamber and the friction pad is not prevented from separating from the side surface of the disc rotor, uneven wear of the lining due to dragging of the disc rotor and generation of rubbing noise are minimized. Will be able to prevent.

Further, by setting the rollback amount of the piston on the disc turn-in side to be larger than the rollback amount of the piston on the disc turn-out side, the time for the piston on the disc turn-in side to push the friction pad is set. Since the leading action that occurs on the disc entry side of the friction pad is suppressed by reducing the amount of pistons on the disc extension side, uneven wear of the lining due to the leading action is prevented as much as possible.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a main part of a caliper body showing an example of the present invention.

FIG. 2 is a cross-sectional plan view of a caliper body showing an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc brake 2 ... 6 Caliper body 2a, 2b of pot opposing type 2a, 2b ... Caliper half 2c, 2d ... Working part 3 ... Disc rotor 4, 5, 6 ... Cylinder hole 10 ... Friction pad 10a ... Lining 10b ... Back plate 11 , 13 ... Seal groove 13a, 13b ... Space portion 13c ... Space portion 13a outer peripheral inclined surface 12 ... Dust seal 14, 15, 16 ... Square seal 17, 18, 19 ... Piston 20, 21, 22 ... Hydraulic chamber 23 ... Liquid Through hole 24 ... Communication hole A ... Rotation direction of disk rotor 3

Claims (2)

[Claims] 1. A pair of operating portions are arranged opposite to each other on both sides of a disk rotor that rotates in one direction as the vehicle travels.
Three or more sets of cylinder holes facing each other across the disc rotor are arranged in parallel in the disc circumferential direction in the pair of action parts, and pistons are housed in the respective cylinder holes in a liquid-tight and movable manner via angular seals, respectively. In a multi-pot opposed type caliper body of a vehicle disc brake in which a hydraulic chamber is defined between each piston and a bottom wall of a cylinder hole, the piston is pulled back toward the hydraulic chamber by the restoring force of the angular seal. The feature is that the amount of rollback of the piston at the time of braking release is set to be larger in the intermediate piston between the pistons on the disk entry side and the exit side than on the pistons on the disk entry side and the exit side. A multi-pot opposed type caliper body for disc brakes for vehicles. 2. The roll-back amount of the piston on the disc feed-in side is set to be larger than the roll-back amount of the piston on the disc feed-out side.
A multi-pot opposed type caliper body for the vehicle disc brake described.