JPH0526359Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a dust seal for a disc brake, and in particular, to a dust seal for a disc brake, which is equipped with a mechanically operated parking brake mechanism that pushes a friction pad by rotation of a camshaft. The present invention relates to a dust seal provided between a camshaft of a vehicle disc brake device and a bearing portion of a caliper on which the camshaft is rotatably provided.

[Conventional technology]

For example, a disc brake for a vehicle disclosed in Japanese Utility Model Application Publication No. 56-168630 has a camshaft rotatably provided in a bearing part of a caliper, and a brake fixed to the shaft part of the camshaft extending from the bearing part. Equipped with a mechanically operated parking brake mechanism that uses a lever to rotate the camshaft and push the friction pad, preventing water, dust, mud, etc. from entering between the bearing and the camshaft shaft. In order to prevent this, an annular outer seal part that fits into a groove formed around the inner periphery of the bearing part, an annular inner seal part that fits into a groove formed around the outer periphery of the shaft part of the camshaft; A dust seal having a connecting portion that connects the seal portion is disposed between the bearing portion and the shaft portion of the camshaft.

[The problem that the idea attempts to solve]

However, in the disc brake with the above structure, when the camshaft is rotated by the brake lever, the camshaft slightly reciprocates in the axial direction with respect to the bearing part.
The only seal between the camshaft and the dust seal is an annular inner seal that fits into a groove formed around the outer circumference of the camshaft shaft, so this reciprocating motion and rotation of the camshaft will cause the dust seal to deteriorate. If this happens, there is a concern that water, mud, etc. may enter the inside of the dust seal.

In addition, the dust seal shown in Japanese Utility Model Publication No. 58-7174 is arranged between a cylinder and a piston that move relatively reciprocatingly, and is connected to an annular inner seal part that fits into a groove on the outer circumference of the piston, and then to the outer circumferential wall of the piston. However, since the pressing force of the lip part is low, as it deteriorates, the adhesion strength decreases and the function deteriorates.Furthermore, due to pressure changes inside the dust seal due to relative reciprocating movement, the inside There is a concern that water, mud, etc. may enter the inside of the dust seal due to slight movement of the seal portion.

Therefore, the present invention doubles the sealing part between the camshaft and the dust seal, and ensures the pressing force of the sealing part against the camshaft, so that even if the sealing part deteriorates, water, mud, etc. will not enter the inside. The purpose is to provide a dust seal without dust.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a camshaft rotatably provided in a bearing part of a caliper, and a brake lever fixed to a shaft part of the camshaft extending from the bearing part to rotate the camshaft. A disc brake that pushes a friction pad, and an annular outer seal part that is disposed between the bearing part and the shaft part of the camshaft and that fits into a groove formed around the inner periphery of the bearing part; In the dust seal of a disc brake device for a vehicle, the dust seal has an annular inner seal portion that fits into a groove provided around the outer periphery of the shaft portion of the camshaft, and a connecting portion that connects both the seal portions, the inner seal of the connecting portion. an annular lip extending along the shaft from the side of the lip, forming an annular sealed space between the inner side of the base and the shaft, and having a tip protruding radially inward;
It is characterized in that the outer side of the base of the lip portion and the outer side of the connecting portion continuous thereto are formed thick.

[Effect]

With this configuration, the camshaft and dust seal are sealed by the inner seal part and the lip part, and the tip of the lip part is strongly pressed against the camshaft by the annular sealed space inside the base. The pressing force of the lip portion and the inner seal portion against the camshaft can be ensured by the reaction force on the outside of the base of the lip portion and the outside of the connecting portion continuous thereto.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The caliper 2 of the disc brake 1 connects an action part 2a and a reaction part 2b, which push a pair of friction pads 4 and 5 facing each other on both sides of the disc rotor 3, with a bridge part 2c that straddles the disc rotor 3. The disc rotor 3 is supported movably in the axial direction by sliding pins 7, 7 on a bracket 6 fixed to the disc rotor 3.

The action portion 2a of the caliper 2 is formed with a cylinder hole 8 that opens toward the disk rotor 3, and a small diameter cylinder hole 9 that is continuous with the cylinder hole 8. A cam of a mechanical parking brake mechanism is installed at the rear of the small diameter cylinder hole 9. A bearing portion 11 on which the shaft 10 is mounted is provided in a direction perpendicular to the cylinder axis.

A tip-shaped piston 12 is fitted into the cylinder hole 8 in a fluid-tight and movable manner, and defines a hydraulic chamber 13 between the cylinder hole 8 and the bottom of the cylinder hole 8.
3 is provided with an introduction hole 14 for introducing pressure fluid supplied from a master cylinder (not shown), and when the fluid pressure in the fluid pressure chamber 13 increases, the piston 12 pushes the friction pad 4. As it comes into pressure contact with one side of the disc rotor 3, the entire caliper 2 moves toward the acting part 2a side due to the reaction force acting on the piston 12, and the reaction part 2b of the caliper 2 pushes the other friction pad 5, causing the disc rotor to move. The disc rotor 3 is pressed against the other side of the friction pads 4 and 5, and the disc rotor 3 is pressed between the two friction pads 4 and 5 to perform a braking action by hydraulic pressure operation.

Further, in the hydraulic pressure chamber 13, an automatic braking gap adjustment device 15 is disposed that compensates for the amount of wear on the friction pads 4 and 5 and automatically sets a constant braking gap.

The braking gap automatic adjustment device 15 includes an adjustment nut 17 whose rotation is regulated by the piston 12 and is urged toward the piston 12 by a spring 16;
It consists of an adjustment bolt 18 that is threaded into the adjustment nut 17 with a multi-start thread, and a sleeve piston 20 whose rotation is restricted by a pin 19 at the bottom of the cylinder hole 8 and which is clutch-engaged with the adjustment bolt 18.

The sleeve piston 20 consists of a large diameter part 20a arranged in the cylinder hole 8 and a small diameter part 20b fitted in the small diameter cylinder hole 9 in a liquid-tight and movable manner. A spherical recess 20c that engages with one end of 21 is formed.

A cylindrical camshaft 10 is attached to the bearing 11 at the rear of the small diameter cylinder hole 9 via a bearing 22, and a cam groove 10a formed in the camshaft 10 and the recess 20c of the sleeve piston 20 are provided with a cylindrical camshaft 10. ,
A driven rod 21 is interposed.

A dust seal 23 is installed between the bearing portion 11 and the shaft portion 10b of the camshaft 10, and a brake lever 24 is attached to the shaft portion 10b of the camshaft 10 extending from the bearing portion 11 to the outside of the caliper 2. A return spring 25 is disposed between the two and is fastened with a long nut 26.

As a result, when the brake lever 24 is rotated, the camshaft 10 rotates and pushes the driven rod 21 toward the disk rotor 3, and the sleeve piston 2
0, Adjustment bolt 18, Adjustment nut 1
The piston 12 is moved toward the disc rotor 3 via the piston 7, and the friction pad 4 is pressed against one side of the disc rotor 3.
The entire caliper 2 moves toward the acting part 2a side due to the reaction force acting on the caliper 2, and the reaction part 2b of the caliper 2 pushes the other friction pad 5 to press it against the other side of the disc rotor 3, so that both friction pads 4, 5, the disc rotor 3 is compressed to perform a braking action by mechanical operation.

The dust seal 23 includes an annular outer seal portion 23a that fits into a groove 11a provided around the inner circumference of the bearing portion 11, and an annular outer seal portion 23a that fits into a groove 11a provided around the inner circumference of the bearing portion 11, and an outer circumference of the shaft portion 10b of the camshaft 10 opposite to the outer seal portion 23a. The abutting convex seal portion 23b and the annular inner seal portion 23c that fits into the groove 10c provided around the outer periphery of the shaft portion 10b.
and a connecting portion 23d that connects the outer seal portion 23a and the inner seal portion 23c, and the connecting portion 23d
Shaft part 1 of camshaft 10 from the inner seal part 23c side of
An annular shaft-side lip portion 23e extends along the axis 0b.

The lip portion 23e is formed such that an annular sealed space 27 is formed between the inner side 23f of the base and the shaft portion 10b, and a tip 23g protrudes radially inward, and the outer side of the base of the lip portion 23e. 23h
and the outer side of the connecting part 23d which is continuous thereto are formed thick, and furthermore, on the outside of the connecting part 23d, there is a bearing part side lip part 23i which comes into pressure contact with the outer surface of the caliper 2 which is the outer side of the bearing part 11. However, the connecting part 23
An annular sealed space 2 between d and the outer surface of the caliper 2
8.

With this configuration, the shaft portion 10b of the camshaft 10
Since the dust seal 23 is sealed at three locations: the tip 23g of the shaft-side lip portion 23e, the inner seal portion 23c, and the convex seal portion 23b, waterproofness is improved.

Moreover, the shaft side lip portion 23e and the base inner side 23f
Since the annular closed space 27 is formed between the shaft part 10b and the shaft part 10b, the shaft part side lip part 23
The tip 23g of the shaft part 23e is strongly pressed against the shaft part 10b, and since the base outer side 23h of the shaft side lip part 23e and the outer side of the connecting part 23d continuous therewith are formed thick, the reaction force acting thereon is The force ensures the pressing force of the shaft side lip part and the inner seal part against the camshaft, and even if the dust seal 23 deteriorates,
By ensuring its elasticity, water and mud are prevented from entering between the shaft portion 10b of the camshaft 10 and the dust seal 23.

In addition, the bearing part side lip part 2 on the outside of the connecting part 23d
3i forms an annular sealed space 28 between the connecting portion 23d and the outer surface of the caliper 2, and is in pressure contact with the outer surface of the caliper 2, which is the outside of the bearing portion 11.
Since the bearing part 11 is sealed at two places, the bearing part side lip part 23i and the outer seal part 23a, the waterproof property is improved.

Furthermore, the bearing side lip part 23i serves to receive the reaction force between the shaft side lip part 23e and the inner seal part 23c, and ensures the pressing force between the shaft part side lip part 23e and the inner seal part 23c. The reaction force of the bearing side lip 23i is transferred to the shaft side lip 23e.
and the inner seal portion 23c to ensure the pressing force of the bearing side lip portion 23i.

[Effect of idea]

As described above, the present invention has a bearing part of a caliper.
A dust seal disposed between the bearing part and the shaft part of the camshaft of a disc brake that is equipped with a camshaft that is rotated by a brake lever and pushes a friction pad by rotating the camshaft. , an annular outer seal portion that fits into a groove provided on the inner periphery of the bearing portion;
An annular inner seal portion that fits into a groove provided around the outer periphery of the shaft portion of the camshaft, and a connecting portion that connects both seal portions are provided, and a ring-shaped inner seal portion is provided along the shaft portion from the inner seal portion side of the connecting portion. An annular lip portion extending from the lip portion is formed such that an annular sealed space is formed between the inner side of the base portion and the shaft portion, and a tip thereof projects radially inward, and the outer side of the base portion of the lip portion Since the outer side of the connecting part continuous with this is formed thick, the camshaft shaft can be connected to the tip of the lip of the dust seal,
It is sealed with the inner seal part to improve waterproofness. Moreover, since the inner side of the base of the lip part forms an annular sealed space between it and the shaft part,
The tip 23g of the lip portion 23e is strongly pressed against the shaft portion 10b, and since the outer side of the base of the lip portion and the outer side of the connecting portion continuous thereto are formed thick, the reaction force acting thereon It is possible to secure the pressing force of the lip part and the inner seal part against the camshaft, and even if the dust seal deteriorates, its elasticity is ensured to prevent water or mud from entering between the camshaft shaft part and the dust seal. To prevent.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a partially sectional plan view of a disk brake, and Fig. 2 is a sectional view of a dust seal. 1... disk brake, 2... caliper, 3
...Disc rotor, 4, 5...Friction pad, 1
0: camshaft, 10b: shaft portion of camshaft, 10c
... Camshaft groove, 11... Bearing portion, 11a...
Bearing groove, 23... Dust seal, 23a...
...outer seal portion, 23c...inner seal portion, 23
d: connecting portion, 23e: shaft side lip portion, 23
f: inner side of the base of the shank side lip; 23g: tip of the shank side lip; 23h: outer side of the base of the shank side lip.

Claims (1)

[Scope of utility model registration request] A camshaft is rotatably installed in the bearing part of the caliper,
The disc brake is a disc brake that pushes a friction pad by rotating the camshaft using a brake lever fixed to the shaft of the camshaft extending from the bearing, and in which the shaft of the camshaft extends from the bearing. an annular outer seal portion disposed between the camshaft and the camshaft, and an annular outer seal portion that fits into a groove formed around the inner periphery of the bearing portion; and an annular inner seal portion that fits into a groove formed around the outer periphery of the shaft portion of the camshaft. In the dust seal for a vehicle disc brake device, the dust seal has a connecting portion connecting both seal portions, and an annular lip portion extending along the shaft portion from the inner seal portion side of the connecting portion is connected to the inner side of the base portion and the shaft portion. An annular sealed space is formed between the lip part and the tip thereof projects inward in the radial direction, and the outside of the base of the lip part and the outside of the connecting part continuous thereto are formed thick. Features a dust seal for disc brake devices for vehicles.