JP3435526B2 - Disc brake - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved caliper floating disc brake.

[0002]

2. Description of the Related Art A disc brake mounted on an automobile or the like straddles a disc bore and a cylinder bore in which a piston facing a pad arranged on one side of a disc rotor that rotates with a wheel is fitted through a piston seal. A caliper having a claw portion facing the pad on the opposite side is movably supported by a carrier fixed to the vehicle body side,
By supplying pressure oil from the master cylinder into the cylinder bore and advancing the piston, one pad is pressed directly against the disc rotor, and the reaction force moves the caliper to move the other pad through the claw. There is a caliper floating disc brake that is pressed against a disc rotor to generate a braking force.

Generally, in this type of disc brake,
The piston seal follows the movement of the piston during braking and elastically deforms, and when braking is released, the piston retracts (falls back) by the amount of elastic deformation of the piston seal, so the clearance between the disc rotor and the pad is always kept constant. It is like this.

[0004]

However, the above-mentioned conventional caliper floating disc brake has the following problems. That is, when the braking is released, the one pad is separated from the disc rotor due to the retreat of the piston, but the other pad is brought into contact with the disc rotor by the claw portion of the caliper, so that the drag is prevented. When this occurs, the running resistance of the vehicle increases and the fuel consumption deteriorates.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a caliper floating type disc brake capable of reliably preventing drag.

[0006]

[Means for Solving the Problems ]
Therefore, the invention according to claim 1, the piston facing one of the pair of pads arranged on both sides of the disk rotor,
In a caliper floating disc brake in which a carrier is movably supported by a caliper having a claw portion that straddles the disc rotor and faces the other of the pair of pads, a guide hole formed in the carrier and the guide hole One end is inserted into the claw part or the pad on the claw part side.
The caliper, which has a pin connected thereto and a fallback seal provided between the pin and the guide hole and elastically deformed following the movement of the pin, moves the caliper moved to the braking position by the movement of the piston to the fall position. characterized in that a caliper retraction mechanism for a certain distance in the backward movement of the pin by the elastic force of the back shielding Thus the non-braking position. According to a second aspect of the present invention, in the structure of the first aspect, a cutout portion is formed in the claw portion of the caliper so as to face the piston, and the guide hole is formed so as to face the cutout portion. It is characterized by Also, the claims
The invention according to claim 3, in the structure of claim 1 or 2,
The moving distance of the pin due to the elastic force of the fallback seal is about one half of the moving distance of the piston due to the elastic force of the piston seal for moving the piston from the braking position to the non-braking position. Characterize.

[0007]

According to the structure of claim 1, when the braking is released,
Since due to retraction of Yorupin the elastic force of the fallback seal <br/> Te caliper moved by a predetermined distance to the non-braking position, it is possible to separate the pad that faces the claw portion of the caliper from the disc rotor. According to the configuration of claim 2, the guide hole and the pin can be arranged in the cutout portion of the claw portion. Further, according to the configuration of claim 3, the retreat distances of the pad on the piston side and the pad on the claw portion side of the caliper to the non-braking position can be made substantially equal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 1 to 3, the disc brake 1 is a caliper floating disc brake.
A cylinder bore 4 is formed in the caliper body 2 so as to face one surface of a disk rotor 3 which rotates with wheels (not shown), and to face the opposite surface across the disk rotor 3. The claw portion 5 is formed. A notch portion 6 is formed in the claw portion 5 at a portion facing the cylinder bore 4. The notch 6 is used as a relief for a tool when machining the inner diameter of the cylinder bore 4. A piston 8 is slidably fitted in the cylinder bore 4 via a piston seal 7. An inner pad 9 is provided between the disc rotor 3 and the piston 8,
An outer pad 10 is provided between the disc rotor 3 and the claw portion 5. In the figure, 11 is a dust boot.

The caliper body 2 is supported by a carrier 12 fixed to the vehicle body so as to be movable along the axial direction of the disc rotor 3 guided by a slide pin (not shown). Also, the inner pad 9 and the outer pad 10
Are supported by the carrier 12 so as to be movable along the axial direction of the disk rotor 3 guided by the grooves 12a (see FIG. 3).

When pressure oil is supplied into the cylinder bore 4 from a master cylinder (not shown), the piston 8 moves forward while elastically deforming the piston seal 7, and directly presses the inner pad 9 against the disc rotor 3.
The reaction force causes the caliper main body 2 to move and press the outer pad 10 against the disk rotor 3 via the claw portion 5 to generate a braking force. When the supply of the pressure oil from the master cylinder is released, the elastic force of the piston seal 7 causes the piston 8 to retreat by the amount of the deformation and the braking is released. Here, if the movement amount of the piston 8 during braking increases due to wear of the pad, slippage occurs between the piston 8 and the piston seal 7 and the piston 8 follows the wear of the pad, so the braking is released. At this time, the piston 8 retreats for a certain distance by the elastic deformation of the piston seal 7, and the clearance between the disc rotor 3 and the pad is always kept constant.

Next, the caliper retracting mechanism 13 which constitutes the urging means, which is an essential part of the present invention, will be described.

A boss portion 14 is formed on the carrier 12 so as to face the cutout portion 6 of the caliper body 2, and a guide hole 15 is provided in the boss portion 14. A fallback seal 17 is fitted in an inner circumferential groove 16 formed in the guide hole 15, and a pin 18 is slidably inserted in the guide hole 15 via the fallback seal 17. As shown in FIG. 2, chamfered portions 16a and 16b are formed at the edges of the inner circumferential groove 16. Then, the fallback seal 17 follows the movement of the pin 18 and elastically deforms along the chamfered portions 16a and 16b, and after the fallback seal 17 abuts the chamfered portions 16a and 16b, It is designed to slip with the pin 18. As a result, with respect to the movement of the pin 18, an urging force in a direction of retracting by the elastic deformation of the fallback seal 17 acts. That is, the fallback seal 17 and the pin 18 constitute an urging means for urging the caliper main body 2, which has been moved to the braking position, to the non-braking position side by a predetermined distance and urging it in the direction. In addition, fallback seal 17
The retracting distance of the pin 18 due to the elastic force of the piston seal 7
It is designed to be about one half of the retracted distance of the piston 8 due to the elastic force of.

A plate 20 is attached to a screw portion 18a formed at one end of the pin 18 by a nut 19.
The plate 20 is attached to the pawl portion 5 by a retainer spring 22 by abutting against a seat surface 21 formed on the outer peripheral portion of the cutout portion 6 facing the outer pad 10, and the pin 18 is attached via the plate 20 to the caliper. It is connected to the main body 2.

A mounting groove is formed on the outer periphery of the boss portion 14 of the caliper 12.
23 is provided, and a dust boot 24 for covering the pin 18 to prevent dust and rust on the sliding portion is attached to the mounting groove 23. In addition, as shown in FIG. 4, the dust boot 24 is attached to the boss portion 14 by providing the attachment groove 25 on the inner peripheral portion of the guide hole 15 so that the dust boot 24 is attached to the attachment groove 25 and the pin.
You may make it hold | maintain with 18. In this case, the dust boot 24 can be firmly held, and the dust boot 24 can be prevented from falling off when the disc brake 1 is assembled to the vehicle. Also, as shown in FIG.
The dust boot 24 may be provided integrally with the fallback seal 17 so as to be attached to the boss portion 14. In such a case, the number of parts and the number of assembling steps can be reduced.

The operation of the present embodiment configured as described above will be described below.

When pressure oil is supplied from the master cylinder into the cylinder bore 4, the piston 8 directly presses the inner pad 9 against the disk rotor 3, and the reaction force of the piston moves the caliper main body 2 so that the claw 5 moves the outer pad 10 to the disk. A braking force is generated by pressing the rotor 3 against the rotor 3. At this time, the piston seal 7 elastically deforms following the movement of the piston 8, and the fallback seal follows the movement of the pin 18 that moves together with the caliper body 2.
17 is elastically deformed along the chamfered portion 16a of the inner circumferential groove 16.

When the supply of the pressure oil from the master cylinder is released, the elastic force of the piston seal 7 causes the piston 8 to retreat a predetermined distance, so that the inner pad 9 is separated from the disc rotor 3. At the same time, the elastic force of the fallback seal 17 causes the pin 18 and the caliper body 2 to retreat by a predetermined distance, so that the outer pad 10 is separated from the disc rotor 3. In this way, the inner pad 9 and the outer pad 10 are separated from the disc rotor 3 and the braking is released. At this time, the retracting distance of the pin 18 due to the elastic force of the fallback seal is about one half of the retracting distance of the piston 8 due to the elastic force of the piston seal 7,
Disc rotor 3, inner pad 9 and outer pad
Clearance with 10 becomes equal. When the inner pad 9 and the outer pad 10 are worn, the piston seal 7, the piston 8, and the fallback seal 17 are correspondingly worn.
Slippage occurs between the piston 8 and the pin 18
When the piston 18 is retracted by the elastic deformation of the piston seal 7 and the fallback seal 17, the disk rotor 3
The clearance between the inner pad 9 and the outer pad 10 is constantly adjusted.

In this way, when the braking is released, the inner pad 9 and the outer pad 10 are separated from the disc rotor 3 by a predetermined clearance, so that drag can be reliably prevented, running resistance is reduced, and fuel consumption is reduced. Can be improved.

Further, by arranging the caliper retreating mechanism 13 in the notch 6 formed in the claw portion 5 of the caliper main body 2 as a relief of the tool when machining the cylinder bore 4, the empty space is effectively utilized. Therefore, the disc brake does not increase in size.

Next, another embodiment of the caliper retracting mechanism 13 will be described with reference to FIGS. 6 and 7 and FIGS. 8 and 9.

In the one shown in FIGS. 6 and 7, the carrier
The pin 18 inserted into the guide hole 15 of the boss portion 14 of 12 has a screw portion 18a formed on the side opposite to the outer pad 10,
The plate 26 is attached to the screw portion 18a by the nut 19. The plate 26 is attached to the caliper main body 2 with screws 27.
Is bound to. Also, dust boots 28 that cover the pins 18
Has a bellows shape that can be expanded and contracted, and one end is pin 18
Is fitted into the mounting groove 18b formed on the
Is fitted into the mounting groove 23 of. With this configuration, FIG.
Or, the same operation and effect as those shown in FIG. 3 can be obtained.

8 and 9, the pin 18 inserted into the guide hole 15 of the boss portion 14 of the carrier 12 is inserted.
Has a screw portion 18a formed at one end screwed into a screw hole 10a provided in the back metal of the outer pad 10,
The outer pad 10 is directly retracted by 18 to move the caliper body 2. With this configuration,
In addition to the effect similar to that shown in FIG. 1 to FIG.
By retreating 18, the outer pad 10 is directly attached to the disc rotor 3
The outer pad 10 can be effectively prevented from being dragged. Furthermore, the number of parts and the number of assembly steps can be reduced.

[0024]

As described above in detail, according to the disk brake according to the invention of claim 1, when releasing the braking, the retraction of Yorupin the elastic force of the fallback seal Accordingly caliper to a non-braking position side Since it moves a predetermined distance, the pad facing the claw portion of the caliper can be separated from the disc rotor. As a result, it is possible to reliably prevent the disc rotor and the pad from being dragged, and it is possible to reduce running resistance and improve fuel efficiency. According to the disc brake of the invention of claim 2, since the guide hole and the pin can be arranged in the notch portion of the claw portion, the vacant space can be effectively utilized and the disc brake can be increased in size. Absent.
Further, according to the disc brake of the invention of claim 3, since the retreat distances of the pad on the piston side and the pad on the claw portion side of the caliper to the non-braking position can be made substantially equal, these pad clearances are made equal. can do.

[Brief description of drawings]

FIG. 1 is a front vertical sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged view of an inner peripheral groove provided in a guide hole of the device shown in FIG.

3 is a side view of the device of FIG. 1. FIG.

FIG. 4 is a view showing another embodiment of the attachment structure of the dust seal in the apparatus of FIG.

5 is a view showing still another embodiment of the attachment structure of the dust seal in the device of FIG.

FIG. 6 is a front vertical sectional view of another embodiment of the present invention.

FIG. 7 is a side view of the device of FIG.

FIG. 8 is a front vertical sectional view of still another embodiment of the present invention.

9 is a side view of the device of FIG. 8. FIG.

[Explanation of symbols]

1 disc brake 2 Caliper body 3 disk rotor 5 nails 8 pistons 9 Inner pad 10 Outer pad 12 carriers 17 Fallback seal (biasing means) 18 pin (biasing means)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographic data Sho 52-13383 (JP, U) Real development Sho 58-196426 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16D 55/224 112 F16D 65/097

Claims (3)

(57) [Claims] 1. A caliper having a piston facing one of a pair of pads arranged on both sides of a disk rotor and a claw portion facing the other of the pair of pads across the disk rotor is movable to a carrier. In the caliper floating type disc brake supported by the above, a guide hole formed in the carrier, and a pin inserted into the guide hole and having one end connected to the claw portion or a pad on the claw portion side. , the pin is provided between the guide hole and the pin
A fallback seal that elastically deforms following the movement, and the caliper moved to the braking position by the movement of the piston is moved by the elastic force of the fallback seal .
That a certain distance in the retraction of the pin thus to a non-braking position side
A disc brake that is provided with a caliper retracting mechanism . 2. The claw of the caliper is formed with a cutout facing the piston, and the guide hole is formed facing the cutout. Disc brake. 3. The moving distance of the pin due to the elastic force of the fallback seal is one half of the moving distance of the piston due to the elastic force of the piston seal for moving the piston from the braking position to the non-braking position. Disc brake according to claim 1 or 2, characterized in that it is of a degree.