JPS6246735B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc brake mainly used in automobiles.

A pair of arms of an adapter fixed on one side of the rotating disk support the friction pads on both sides of the disk so that they can move in the direction of the disk's rotational axis.
A disc brake is already known in which the friction pad is pressed against the disc by a caliper whose main body is movably supported by the pair of arms in the direction of the disc rotation axis via a pair of pins. In such disc brakes, when braking,
Since one of the pair of arms of the adapter receives the brake torque acting on the friction pad, it deforms in the direction in which the brake torque is applied and the pitch between the pair of pins increases.

However, in conventional disc brakes, the pair of pins are engaged with the pair of pins through a guide hole provided in the main body of the caliper, and an elastic member such as an O-ring is interposed between the guide hole and the pin. Additionally, a lubricant such as grease is applied between the elastic member and the guide hole. Therefore, when the pitch between a pair of pins increases during braking, the increase in pitch is absorbed by the deformation of the elastic member, but at that time, a large load is applied to the lubricant due to the deformation of the elastic member, and the elastic member deforms. A so-called oil curtain phenomenon occurred at the contact portion with the guide hole. As a result of this phenomenon, the sliding part of the pin becomes stiff and cannot slide smoothly in the direction of the disk rotation axis.In other words, the sliding resistance of the caliper increases, making it impossible to perform a reliable braking action, and at the same time, the caliper recovers after the brake is released. There was a problem in that the operation could not be performed smoothly and a so-called friction pad dragging phenomenon occurred.

The present invention is intended to solve the above-mentioned problems of the conventional disc brake, and allows the pin to slide smoothly in the direction of the disc rotation axis without causing twisting of the sliding part of the pin. It is an object of the present invention to provide a disc brake that prevents the occurrence of a dragging phenomenon of friction pads.

In order to achieve the above object, the present invention provides a pair of cylindrical rigid bushes into which a pair of pins fixed to the main body of the caliper can be slidably fitted, and into which the pair of rigid bushes are loosely fitted. A pair of guide holes are respectively formed in the pair of arms of the adapter, and a pair of guide holes are formed between the opposing parts of the outer periphery of each rigid bushing and the inner periphery of each guide hole, the length being shorter than the axial length of the opposing parts and on the arm. It is characterized by a structure in which an annular elastic member is interposed to elastically support a rigid bush.

Embodiments of the present invention will be described below based on the accompanying drawings. In FIG. 1, the disk 10 rotates together with wheels (not shown), and when the automobile moves forward, the disk 10 rotates in the direction of arrow F. disk 1
The adapter 20, which is fixed by being connected to a nutcle (not shown) on one side of the
have. The friction pads 30 and 40 on both sides of the disk 10 are connected to the pair of arms 2 of the adapter 20.
1 and 22 so as to be movable in the direction of the disk rotation axis (in the vertical direction in FIG. 1). During braking, the brake torque acting on the friction pads 30, 40 is received by the arms 21, 22 of the adapter 20. The friction pads 30, 40 are pressed against the disk 10 by a caliper 50 which acts under hydraulic pressure. The caliper 50 includes a main body 51 and a piston 52 that is fitted into a hydraulic cylinder portion 51a of the main body.
The main components are: The caliper main body 51 is supported by the arms 21 and 22 of the adapter 20 via a pair of pins 60 and 70 so as to be movable in the direction of the disk rotation axis.
It has b. When hydraulic pressure is supplied to the inside of the hydraulic cylinder part 51a from the port 53 provided in the hydraulic cylinder part 51a of the caliper main body 51, the piston 52 in the hydraulic cylinder part 51a moves upward in FIG. At the same time, the caliper main body 51 moves downward in FIG. 1 to press the friction pad 40 against the disk 10.

Guide holes 23 and 24 are formed in the arms 21 and 22 of the adapter 20 in the direction of the disk rotation axis, and cylindrical metal bushes (rigid bushes) 25 and 26 are inserted into the guide holes 23 and 24, respectively. The bushes 25, 26 are supported by the arms 21, 22 by shoulders 25a, 26a and stoppers 27, 28, respectively, and are fixed so as not to move in the axial direction.

Pins 60, 70 are slidably inserted into the bushes 25, 26, and the outer ends of the pins 60, 70 are connected to the protrusions 54, 55 of the caliper 50 by bolts 80, 8.
1 are integrally connected. Also, pin 6
Grease is applied as a lubricant between 0 and 70 and bushes 25 and 26. Guide hole 23
Elastic members, ie, square rings 61 and 62 made of an elastic material such as rubber are interposed between the guide hole 24 and the bush 25, and square rings 71 and 72 are similarly interposed between the guide hole 24 and the bush 26. . Furthermore, the first
82 and 83 in the figure are pins 60 and 70 and bush 2.
The boots 82 and 83 are made of an elastic material such as rubber, and have one end attached to the pins 60 and 70 and the other end attached to the bushes 25 and 26. ing.

Next, the operation of the above-described configuration will be explained. First, during braking when the vehicle is moving forward, the arm 21 of the adapter 20 receives the brake torque acting on both the friction pads 30 and 40, causing the arm 21 to deform and the pitch between the pins 60 and 70 to increase. This increase in pitch is absorbed by the elastic deformation action of the square rings 61 and 62, but since the sliding portion of the pin 60 inside the bush 25 is not deformed, there is no possibility that the oil drop phenomenon will occur on the sliding portion of the pin 60. do not have. Therefore, the sliding portion of the pin 60 does not twist, and the caliper 50
Since the sliding resistance does not increase, a reliable braking action can be performed. Next, when braking when the vehicle is traveling backwards, both friction pads 30,
The arm 22 of the adapter 20 receives the brake torque acting on the adapter 40. Although this brake torque is smaller than the brake torque during forward travel, the arm 22 is deformed due to the brake torque, and the pins 60, 70
As the pitch between them increases, this increased pitch is absorbed by the elastic deformation action of the corner rings 71, 72. At this time, the pin 70 slides inside the bush 26, similar to when braking during forward travel.
The sliding part of the pin 70 does not twist.

In addition, the load applied to the elastic members 61, 62, 71, 72 causes the outer periphery of the bushes 25, 26 to shift into the guide holes 23, 26 due to the increase in elastic deformation of these elastic members.
Since the elastic member is restricted by contacting the inner periphery of the elastic member, there is no worry that the elastic member will receive an excessive load and break prematurely.

In the embodiment shown in FIGS. 1 and 2, the pins 60 and 70 are fixed to the caliper 50 and slide against the arms 21 and 22 of the adapter 20, so that the pins 60 and 70, and the guide holes 23, 24 are configured not to slide relative to each other.
and square rings 61, 62 and 71, 72 as elastic members interposed between the metal bushes 25, 26.
is used. As shown in FIG. 3, the pins 60 and 70 are fixed to the adapter 20 so that the caliper 50 slides on the pins 60 and 70, and an O-ring 63 is used instead of the square ring as an elastic member. 64 may be used. In addition, the same symbols in the figures indicate the same or equivalent parts.

As described in detail above, in the disc brake according to the present invention, the cylindrical metal bushes 25 and 2 are installed in the guide holes 23 and 24 formed in the adapter 20.
6, insert the bushes 25, 26 and the guide hole 23,
An elastic member such as square rings 61, 62, 71, 72 or O-rings 63, 64 is interposed between the pins 60, 70 and the bushes 25, 26, and the pins 60, 70 are slidably supported. Therefore, the sliding portions of the pins 60 and 70 do not twist when the brake is applied. As a result, an increase in the sliding resistance of the caliper 50 can be prevented, so that the dragging phenomenon of the friction pads 30, 40 does not occur. The elastic members 61, 62, 71, 72 are shorter than the axial length of the opposing portions of the outer circumferences of the bushes 25, 26 and the inner circumferences of the guide holes 23, 24, and when the amount of deformation of the elastic members reaches a predetermined amount, Since the increase in the load on the elastic member is limited by the contact between the outer circumference of the bush and the inner circumference of the guide hole, the gap between the outer circumference of the bush and the inner circumference of the guide hole is set to the minimum necessary. Since the amount of free displacement can be reduced as much as possible, the present invention has the effect of reducing problems such as uneven wear of the friction pads and problems of interference with wheels and disks, which are significant when the amount of free displacement is large. In addition, Butsuyu 2
Since 5 and 26 are rigid bodies, the elastic members 61 and
The elastic forces of 62, 71, 72, 63, and 64 do not act on the sliding portions of the bushes 25, 26 and the pins 60, 70 as a factor to increase the sliding resistance, and for example, elastic members are used to improve vibration resistance. Even if the elastic force of the elastic member is set to a large value, the sliding resistance of the pins 60, 70 does not increase, and the sliding resistance of the pins 60, 70 can be kept small regardless of the magnitude of the elastic force of the elastic member. There is an effect that can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a partial view showing a modified example. 10...disk, 20...adapter, 21,
22... Arm of adapter, 23, 24... Guide hole, 25, 26... Metal bushing, 30, 40...
...pin, 50...caliper, 51...caliper body, 60,70...pin, 61,62,71,7
2... Square ring, 63, 64... O-ring.

Claims (1)

[Claims] 1 A pair of arms of an adapter fixed on one side of the rotating disk supports the friction pads on both sides of the disk so as to be movable in the direction of the rotational axis of the disk, and the main body of the caliper that presses the friction pads against the disk is fixed to this. In the disc brake, the pair of arms are movably supported in the direction of the disc rotation axis via a pair of pins,
a pair of cylindrical rigid bushes into which the pair of pins are slidably fitted, respectively, a pair of guide holes into which the pair of rigid bushes are loosely fitted are formed in the pair of arms, and each rigid body A disc brake comprising an annular elastic member interposed between the opposing parts of the outer periphery of the bushing and the inner periphery of each guide hole, which is shorter than the axial length of the opposing part and elastically supports the rigid bushing on each arm. .