JPH08232995A - Disc brake caliper - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce drag, prevent rattling noise, and reduce knockback. In a caliper of a disc brake equipped with a slide pin 25, a guide pipe 30 slidably inserted in an inner periphery of a slide hole 20 and a slide pin 25 slidably inserted therein, and a slide pin 25. And a guide pipe 30, and a spring 40 for moving the slide pin 25 with respect to the guide pipe 30 by a predetermined restoration amount α, and a spring inserted between the guide pipe 30 and the inner peripheral surface of the slide hole 20. The rubber rings 34A to 34C for restraining the guide pipe 30 in the slide hole 20 are provided with a force stronger than the urging force of 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caliper for an automobile disc brake.

[0002]

2. Description of the Related Art Floating type calipers are available as calipers for disc brakes for automobiles (issued on December 19, 1992, first edition, published by Grand Prix Co., Ltd., "What is the mechanism of automobile chassis / body system", p. 116-? 12
(See page 2).

This floating caliper is of a type in which the cylinder body slides sideways by the reaction force of pushing out the piston, pulls the friction pad on the opposite side, and presses it against the disc rotor. In this caliper, the cylinder body is connected to the torque member with a slide pin, and the cylinder body slides while being guided by the slide pin during braking and wear of the friction pad.

2 to 5 show an example of a conventional caliper of this type.

As shown in FIGS. 2 to 4, the caliper 1 has a torque member 3 fixed to a vehicle body (for example, a knuckle of a suspension) and a cylinder body 4 supported by the torque member 3. By inserting the slide pin 5 fixed to the cylinder body 4 with the bolt 6 into the slide hole 20 formed in the torque member 3, the cylinder body 4 moves in the direction orthogonal to the disc rotor 2 with respect to the torque member 3. It is slidably connected. The boot 7 is fitted into the inlet of the slide hole 20 as shown in FIG. 4, so that dust and the like does not enter the slide hole 20 from the outside.

Further, the caliper 1 is, as shown in FIG.
A pair of friction pads 1 facing each other across the disc rotor 2
It has 0 and 12. The outer side and inner side friction pads 10 and 12 are held by the cylinder body 4. The piston 16 is pushed in the cylinder chamber 14 of the cylinder body 4 in the pressing direction of the friction pad 12 (disc rotor 2
It is housed slidably along the direction (orthogonal to). A piston seal 18 is arranged on the inner circumference of the cylinder chamber 14, and the inner circumference of the piston seal 18 is the piston 1.
By closely contacting the outer circumference of 6, the gap between the piston 16 and the cylinder chamber 14 is sealed. And the cylinder chamber 1
By introducing hydraulic pressure to the piston 4, the piston 16 moves to press the friction pad 12 against the disc rotor 2.

As described above, when the piston 16 is driven in the arrow (a) direction to press the inner friction pad 12 against the disc rotor 2 during braking, the reaction force causes the cylinder body 4 to move in the arrow (b) direction. The friction pad 10 on the outer side is pressed against the disc rotor 2 by sliding to generate a braking force.

At this time, the piston seal 18 is pulled by the moving piston 16 as shown in FIG. 6, and is elastically deformed within the range of the chamfer 19a of the piston seal groove 19 as shown by N1 → N2 in the figure. .

On the other hand, when the brake is released, the hydraulic pressure is released, and the piston 16 returns by a certain amount due to the elastic restoring action of the piston seal 18, so that a gap is formed between the inner friction pad 12 and the disc rotor 2. Also on the outer side, a slight gap is formed between the friction pad 10 and the disc rotor 2 by releasing the pressing force. The gap at this point is large on the piston 16 side, which is positively pulled back by the piston seal 18, and small on the opposite side. However, since the surface of the disk rotor 2 has minute irregularities, the convex portion of the rotating disk rotor 2 hits the friction pad 10 on the outer side, so that the cylinder body 4 slides laterally and escapes. The gap is also distributed to the outer side, and the gap (usually 0.1 mm or less) between the outer side friction pad 10 and the disc rotor 2 is widened.

During the above operation, the slide pin 5 slides in the slide hole 20 of the torque member 3 and guides the movement of the cylinder body 4.

When the friction pads 10 and 12 are worn, the piston 16 is relatively pushed out with respect to the piston seal 18, and the clearance is automatically adjusted. That is, normally, the piston 16 moves within the elastic deformation range of the piston seal 18 as shown in FIG.
2 is pressed against the disc rotor 2, but when the friction pads 10 and 12 are greatly worn and the movement amount of the piston 16 exceeds the deformation allowable amount of the piston seal 18,
The piston 16 slides relative to the piston seal 18. The amount pushed out by more than the return amount (sliding movement amount) remains as it is even when the brake is released and returns to the returning state, and when restarting, the piston 16 is pressed against the position where it slipped and stopped. Take action. Therefore,
Even if the friction pads 10 and 12 are worn, the disc rotor 2
The clearance between the friction pads 10 and 12 is automatically adjusted, and a predetermined braking force is obtained.

Further, as the position of the piston 16 changes due to the abrasion of the friction pads 10 and 12, the position of the cylinder body 4 also changes. Therefore, the slide pin 5 also moves in the direction of arrow (c) in FIG. 4, and the sliding operation at the time of normal braking is performed with reference to the moved position.

[0013]

By the way, the conventional caliper 1 is not provided with a means for positively returning the cylinder body 4 to the original position except for the elastic force of the piston seal 18 at the time of releasing the braking. That is, the piston 16
On the side (inner side), the return action of the piston seal 18 separates the friction pad 12 from the disc rotor 2, but on the outer side, the convex portion of the surface of the rotating disc rotor 2 hits the friction pad 10, and the cylinder body 4 moves. By sliding laterally and escaping, the friction pad 10 is moved to the disc rotor 2
The friction pad 1
It was not configured to pull 0 away from the disc rotor 2. Therefore, there is a problem that dragging is likely to occur between the friction pads 10 and 12 and the disc rotor 2.

When the friction pad 10 is worn out, the slide pin 5 moves in the direction of coming out of the slide hole 20. Therefore, the fitting length between the slide pin 5 and the slide hole 20 becomes shorter. For example, the wear of the friction pad 10 is about 10 mm at the maximum, and the wear of the disc rotor 2 is 1 at the maximum.
Since it is about mm, the fitting length can be shortened up to about 11 mm. Since a gap (for example, about 0.1 mm) for smooth sliding is ensured in the slide portion (the mutual sliding portion between the slide pin 5 and the slide hole 20), the friction pad 10 is worn away. However, when the fitting length is shortened, there is a problem that the stability of the operation is reduced and rattling noise is generated.

In order to prevent this, a bush may be inserted between the inner circumference of the slide hole 20 and the outer circumference of the slide pin 5, but if this is done, the sliding operation during normal braking may not be smooth.

When traveling on a rough road (particularly when traveling on a continuous wave road at a high speed and receiving a vibration input continuously) or during a sharp turn, as shown by the arrow in FIG. When shaken, the piston 16 may be hit by the friction pad 12 to receive a pushing back force. In this case, the cylinder body including the pad 12 and the piston 16 is usually 2
It is a heavy object that weighs up to 3 kg, and a maximum force of 10 G may be applied. When this force is received, the piston 16 slides back against the piston seal 18, and in particular, the slide pin 5 can freely slide in the slide hole 20, so that the gap H between the friction pads 10 and 12 and the disc rotor 2 is increased.
1 will be wide open. For this reason, when the brake pedal is depressed again, the depression stroke becomes longer,
There is a problem of feeling strange (this phenomenon is called knockback).

In consideration of the above circumstances, the present invention is directed to a disk brake capable of reducing drag during brake release, stabilizing the sliding movement of the cylinder body during normal braking, preventing abnormal noise, and reducing knockback. The purpose is to provide calipers.

[0018]

According to a first aspect of the present invention, a pair of friction pads facing each other with a disk rotor interposed therebetween, a cylinder body holding the friction pads and having a cylinder chamber, and a cylinder chamber of the cylinder body are provided. A piston that is supported via a piston seal to press the friction pad and the disk rotor in cooperation with the cylinder body; and a piston that is fixed to the vehicle body side to support the cylinder body, and to the axial direction of the cylinder chamber. A torque member having a slide hole extending in the same direction, a guide pipe supported on the inner circumference of the slide hole via a friction material, and movable along the slide hole by sliding of the friction material, and the cylinder. A slide pin fixed to the body, inserted into the guide pipe, and movable with respect to the guide pipe; Interposed between a ride pin and the guide pipe, and biases the slide pin with a relatively weaker force than the frictional force of the friction material in a direction in which the one friction pad is separated from the disc rotor, An elastic member for keeping a predetermined stroke of the slide pin with respect to the guide pipe is provided.

A second aspect of the present invention is the caliper of the disc brake according to the first aspect, wherein the friction material is fitted and fixed to the outer periphery of the guide pipe and is in pressure contact with the inner peripheral surface of the slide hole. It is characterized by consisting of a ring.

The invention of claim 3 is the caliper of the disc brake according to claim 2, wherein the rubber ring is
A plurality of guide pipes are arranged at intervals in the longitudinal direction.

According to a fourth aspect of the present invention, there is provided a caliper for a disc brake according to the second or third aspect, wherein a seal material which is in sliding contact with the outer periphery of the guide pipe is fixed to the inlet of the slide hole, and a rubber ring is provided. It is characterized in that it is arranged on the slide hole insertion end side of the guide pipe.

According to a fifth aspect of the present invention, in the caliper of the disc brake according to the fourth aspect, the seal material is integrated with a boot rubber that seals a gap between the slide hole inlet and the slide pin, and one end of the boot rubber is It is characterized in that it is integrated with a sealing material fixed to the entrance of the slide hole, and the other end is fitted and fixed to the outer periphery of the slide pin.

[0023]

According to the first aspect of the present invention, when the piston is driven to press the friction pad on the piston side against the disc rotor during braking, the cylinder body slides due to the reaction force, and the opposite friction pad is pressed against the disc rotor. And generate braking force. At that time, since the guide pipe is held in the slide hole by the friction material with a force larger than the force for returning the slide pin (biasing force of the elastic member), the slide pin slides in the guide pipe.

On the other hand, at the time of releasing the braking, the pressing force of the piston is released, so that the piston seal which is elastically deformed by being pulled by the piston at the time of braking is restored.
The piston returns by a certain amount, and a gap is created between the friction pad on the piston side and the disc rotor. This gap is also distributed to the opposite side by the cylinder body following the slide, but at this time, the slide pin is urged by the elastic member so as to restore a predetermined stroke, so the cylinder body Positively returns to the restored position.

Further, when the friction pad is worn, the cylinder body needs to slide following it, but at that time, the sliding amount of the cylinder body exceeds the above-mentioned restoring stroke of the slide pin. , The guide pipe moves by being pushed by the slide pin by the amount exceeding that. Therefore, the wear of the friction pad is dealt with by the guide pipe sliding by the wear amount and the slide pin sliding in the guide pipe during normal braking. Therefore, the fitting length of the portion where the slide pin is actually fitted (fitting length with respect to the guide pipe) is kept constant regardless of wear of the friction pad, and smooth sliding operation is guaranteed. The rattling noise is suppressed.

The guide pipe slides because
Only when the friction pad is worn, the sliding part of the slide hole and the guide pipe can be made tight (fitting condition of tight fit) by friction material, and rattling noise is generated from this part. Can be almost eliminated.

Further, by tightly attaching the guide pipe to the torque member, the movement of the guide pipe can be suppressed, so that the free movement of the slide pin in at least one direction (the direction hitting the guide pipe) can be restricted. As a result, the shake of the cylinder body during traveling on a rough road can be suppressed and knockback can be reduced.

According to the second aspect of the present invention, since the rubber ring is fitted on the outer circumference of the guide pipe and the rubber ring is pressed against the inner peripheral surface of the slide hole, the friction generated between the rubber ring and the inner peripheral surface of the slide hole. The force allows the guide pipe to be stably restrained.

In the invention of claim 3, the frictional force and stability can be adjusted by the number and arrangement of the rubber rings.

According to the fourth aspect of the invention, the guide pipe is supported in a well-balanced manner by the seal material at the slide hole inlet and the rubber ring at the depth position of the slide hole, and rattling can be reliably prevented, and the seal member has the rubber ring. The contact prevents the guide pipe from coming off.

According to the fifth aspect of the invention, since the seal material and the boot rubber are integrated, it is possible to suppress an increase in the number of parts and the number of steps for mounting.

[0032]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the construction of the essential parts of the caliper of the embodiment. The configuration of other parts is the same as that shown in FIGS.

On the other hand, in the caliper of this embodiment, the guide pipe 30 is inserted into the slide hole 20 formed in the torque member 3 so as to be slidable in the longitudinal direction. The slide pin 25 is inserted in the guide pipe 30. A plurality (here, three) are provided on the outer peripheral surface of the guide pipe 30 that is inserted into the slide hole 20 (on the left side in the figure).
Annular fitting grooves 32 are provided at intervals in the longitudinal direction, and a rubber ring (friction material) 34 is provided in each annular fitting groove 32.
A, 34B and 34C are fitted together. Rubber ring 3
The outer circumferences of 4A, 34B, and 34C are in pressure contact with the inner peripheral surface of the slide hole 20, and the guide pipe 30 is restrained with respect to the slide hole 20 by a frictional force.

A spring seat 27 is provided at the tip of the slide pin 25, and a spring accommodating portion 36 is provided at the inner circumference of the tip of the guide pipe 30. The tip of the spring (elastic member) 40 accommodated in the spring accommodating portion 36 is in contact with the spring seat 27. The slide pin 25 is this spring 4
0 is urged to the left in the figure (the direction in which the outer side friction pad 10 is separated from the disc rotor 2).
The biasing force is the same as that of the rubber rings 34A to 3A described above.
It is set to be smaller than the restraining force due to friction of 4C.

A gap α of a predetermined size is secured between the spring seat 27 and the tip of the guide pipe 30.
This clearance α may be secured by appropriately setting the free length of the spring 40, or a clearance F2 between the end surface of the large diameter portion 28 provided on the proximal end side of the slide pin 25 and the end portion of the guide pipe 30. Can be accurately ensured by setting zero to zero, that is, by applying the end surface of the large-diameter portion 28 to the end portion of the guide pipe 30, but here, the clearance between the friction pad on the piston side and the disc rotor is dealt with. Have been secured.

A boot rubber 7 is arranged on the inlet side of the slide hole 20. The boot rubber 7 has an annular seal portion (sealing material) 7 a fitted and fixed to the entrance of the slide hole 20, and a fitting portion 7 b fitted to the outer periphery of the base end portion of the slide pin 25. The seal portion 7a is in sliding contact with the outer peripheral surface of the guide pipe 30, and also serves as a retainer for the slide pin 25.

Next, the operation will be described.

During normal braking, as shown in FIG. 5, when the piston 16 is driven to press the inner friction pad 12 against the disc rotor 2, the reaction force causes the cylinder body 4 to slide, causing friction on the outer side. The pad 12 is pressed against the disc rotor 2 to generate a braking force. At that time, the guide pipe 30 shown in FIG.
Since it is held in the slide hole 20 by 34C, the slide pin 25 slides in the guide pipe 30 in the direction of the arrow (c), and the spring seat 27 and the guide pipe 30
The gap α between them is filled.

On the other hand, when the brake is released, the pressing force of the piston 16 is released, and the piston 16 returns by a certain amount due to the elastic action of the piston seal 18, so that a gap is created between the inner friction pad 12 and the disc rotor 2. You can This gap is distributed to the opposite side as the cylinder body 4 slides following it. At that time, the slide pin 25 is urged by the spring 40 so as to be restored by the gap α (predetermined restoration amount). Therefore, the cylinder body 4 positively returns to the restoration position. Therefore, the friction pad 10 can always be returned by the determined restoration amount α, and drag can be reduced.

When the friction pad 10 is worn,
The cylinder body 4 needs to slide following it, but at that time, the amount of slide of the cylinder body 4 exceeds the restoration amount α of the slide pin 25 described above. Pushed by the spring seat 27 fixed to 25, the guide pipe 30 moves in the arrow (c) direction in FIG.

Therefore, with respect to the wear of the friction pad 10, the guide pipe 30 slides by the wear amount, and the slide pin 25 slides in the guide pipe 30 during normal braking. Therefore, the slide pin 2
The fitting length of the part where 5 is actually fitted (guide pipe 3
The fitting length with respect to 0) is kept constant regardless of wear of the friction pad 10, a smooth sliding operation is guaranteed, and rattling noise is suppressed.

Since the guide pipe 30 slides only when the friction pad 10 is worn, the sliding portions of the slide hole 20 and the guide pipe 30 are tight (tight fit) by the rubber rings 34A to 34C. It can be kept in a combined state). Therefore, rattling noise is hardly generated from this portion.

Further, the guide pipe 30 is connected to the torque member 3
If the slide pin 25 is tightly attached to the cylinder body 4,
Since it is possible to regulate the amount of movement of the cylinder body 4, it is possible to suppress the shake of the cylinder body 4 during traveling on a bad road, and it is possible to reduce the knockback phenomenon caused by the shake.

Further, according to the structure of the embodiment, the seal portion 7a of the boot rubber 7 is slidably contacted with the outer periphery of the guide pipe 30 at the inlet of the slide hole 20, and the rubber rings 34A to 34C are provided at the inner position of the slide hole 20 so that the rubber rings 34A to 34C are guided. Three
Since 0 is supported, the guide pipe can be reliably supported in a well-balanced and stable manner, and rattling can be reliably prevented, and the rubber rings 34A to 34C can seal the boot rubber 7.
The slide pin 25 can be prevented from coming off by hitting a. In addition, since the seal portion 7a is integrally formed with the boot rubber 7, it is possible to suppress an increase in the number of parts and the number of mounting steps. Furthermore, rubber rings 34A to 34C
The frictional force and stability can be adjusted by the number and arrangement of the guides, and the restraining force of the guide pipe 30 can be easily set or changed.

[0046]

As described above, according to the first aspect of the present invention, the elastic member provided between the slide pin and the guide pipe urges the slide pin to return by a predetermined restoration amount. , When the brake is released, the friction pad on the side opposite to the piston can always be returned by a predetermined restoration amount, and drag can be reduced. Further, regardless of the abrasion of the friction pad, a constant fitting length can be always secured between the slide pin and the guide pipe, so that a smooth sliding operation can be guaranteed and abnormal noise can be reduced. Further, by tightly attaching the guide pipe to the torque member, knockback can be reduced and good braking characteristics can be obtained.

According to the second aspect of the present invention, since a stable holding force of the guide pipe can be obtained, rattling and movement of the guide pipe during normal braking can be suppressed.

According to the third aspect of the present invention, since the frictional force and stability can be adjusted by the number and arrangement of the rubber rings, it is possible to easily set or change the restraining force of the guide pipe.

According to the invention of claim 4, rattling of the guide pipe can be surely suppressed, and the guide pipe can be prevented from coming off by the sealing material.

According to the fifth aspect of the invention, since the seal material is integrated with the boot rubber, the number of parts and the number of mounting steps are not increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a caliper according to an embodiment of the present invention.

FIG. 2 is an external view of a conventional caliper.

FIG. 3 is a view on arrow III in FIG.

FIG. 4 is a cross-sectional view showing a structure around a conventional slide pin.

5 is a sectional view taken along the line IV-IV in FIG.

FIG. 6 is an explanatory view of the action of a piston seal in a conventional caliper.

FIG. 7 is a cross-sectional view shown for explaining a conventional problem.

[Explanation of symbols]

 1 Caliper 2 Disc Rotor 3 Torque Member 4 Cylinder Body 7 Boot Rubber 7a Seal Part (Seal Material) 10, 12 Friction Pad 16 Piston 18 Piston Seal 20 Slide Hole 25 Slide Pin 40 Spring (Elastic Member) 30 Guide Pipe 34A-34C Rubber Ring (Friction material) α gap (predetermined restoration amount)

Claims (5)

[Claims] 1. A pair of friction pads facing each other across a disc rotor, a cylinder body holding the friction pad and having a cylinder chamber, and the friction pad supported in the cylinder chamber of the cylinder body via a piston seal. And a piston that presses the disk rotor in cooperation with the cylinder body, and a slide hole that is fixed to the vehicle body side to support the cylinder body and that extends in the same direction as the axial direction of the cylinder chamber. A torque member, a guide pipe supported on the inner circumference of the slide hole via a friction material, and movable along the slide hole by sliding of the friction material, fixed to the cylinder body, and attached to the guide pipe. A slide pin that is inserted and movable with respect to the guide pipe; the slide pin and the guide pipe And slides the one of the friction pads toward the direction in which the one friction pad is separated from the disc rotor, and urges the slide pin with a force relatively weaker than the friction force of the friction material. And a resilient member that keeps the stroke of the guide pipe with respect to the guide pipe. 2. The caliper for the disc brake according to claim 1, wherein the friction material is a rubber ring that is fitted and fixed to the outer circumference of the guide pipe and presses against the inner circumference of the slide hole. Characteristic disc brake caliper. 3. The caliper for a disc brake according to claim 2, wherein a plurality of the rubber rings are arranged at intervals in the longitudinal direction of the guide pipe. 4. The caliper for the disc brake according to claim 2, wherein a seal material that is in sliding contact with the outer periphery of the guide pipe is fixed to the inlet of the slide hole, and a rubber ring is provided in the slide hole of the guide pipe. A disc brake caliper that is arranged on the insertion end side. 5. The caliper for a disc brake according to claim 4, wherein the sealing material is integrated with one end of boot rubber that seals a gap between the inlet of the slide hole and the slide pin, and the other end of the boot rubber is the other end. A disc brake caliper that is fitted and fixed to the outer periphery of a slide pin.