JPH0220509Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a disc brake device for a vehicle equipped with a mechanical actuation mechanism.

[Conventional technology]

Conventional disc brake devices of this type include, for example, a hydraulic actuation mechanism operated by pressure fluid from a master cylinder and a mechanical actuation mechanism as a parking brake mechanism, which uses a camshaft with a cam groove. Installed on the caliper,
It is known that this camshaft is rotated by a brake lever and a driven rod engaged with the cam groove is driven to mechanically push a friction pad to perform a braking action.

In this type of disc brake device, a bearing part is provided at the rear of the cylinder of the caliper that houses the piston, and a camshaft having a cam groove formed in the bearing part is rotatably inserted into the bearing part, and the camshaft shaft extending from the bearing part of the camshaft is rotatably inserted into the bearing part. A brake lever is attached to the part, and the brake lever is biased in the counter-braking direction by the torsionally resilient force of the coil spring.

As shown in FIG. 5 or 6, this coil spring is wound around the outer periphery of a long nut 3 that fastens the brake lever 2 to the extending portion of the camshaft 1. One end 4 of the brake lever 2 is locked to the tip side of the brake lever 2, and the other end, which is the fixed side, is connected to the fifth end.
In the case shown in the figure, an end portion 5 extending linearly in the tangential direction is formed, and the end portion 5 on the fixed side is applied to the side surface of a stopper pin 7 which is erected on a caliper 6, and a resilient force in the torsional direction of the coil is applied. The brake lever 2 is held in such a way that it contacts at one point and urges the brake lever 2 in the anti-braking direction (direction of arrow A), and in the case shown in FIG. 8, and the end portion 8 is latched so as to be wrapped around the outer circumference of the stopper pin 7 to bias the brake lever 2 in the direction of counter-braking action (direction of arrow A) and to prevent the force of the coil spring during braking action. It is locked so as to restrict movement in the direction away from the stopper pin 7.

[Problem that the invention attempts to solve]

Therefore, when the brake lever 2 rotates in the braking action direction (arrow B direction) during braking, the coil diameter of the coil spring decreases and the entire coil spring attempts to move in the opposite direction to the stopper pin 7. In the former case, the coil spring is poorly seated and may try to slip out from the outer periphery of the long nut 3 wrapped around it, causing the entire coil spring to tilt; Since the end 8 is wrapped around the outer circumference of the stopper pin and locked, the coil spring is prevented from moving when the brake lever 2 is rotated in the direction of braking action (direction of arrow B). There was a problem in that stress was concentrated on the end 8 which was curved into a hook shape, so that the end 8 was easily damaged.

The present invention was developed in view of the above points, and it restricts the movement of the coil spring in the release direction during the braking operation, which biases the brake lever provided in the mechanical actuation mechanism of the disc brake device in the anti-braking action direction. Its purpose is to provide disc brake devices for vehicles.

[Means for solving problems]

As a means to solve the above-mentioned problems, the present invention uses a camshaft in which a friction pad that presses against a brake disc to perform braking is inserted into a bearing part of a caliper, and is mechanically pushed by rotating a camshaft. A brake lever attached to a camshaft is wound around the outer periphery of the camshaft, and one end of the coil spring is locked to the brake lever and the other end is locked to a stopper pin provided upright on the caliper. In a disc brake device for a vehicle that is biased in the direction of counter-braking motion by an elastic force, the fixed side end of the coil spring that engages with the stopper pin is formed in a U-shape, and the U-shaped A stopper pin with an end bent toward the opposite side of the caliper and a large-diameter head formed at the tip is installed upright on the caliper, and the U-shaped end of the coil spring is connected to the stopper pin to adjust the coil radius of the coil spring. It is characterized in that it is latched to allow movement in the direction, and that the U-shaped end is arranged so as to press against the surface of the large diameter head of the stopper pin on the caliper side.

[Effect]

With this configuration, the coil spring is always biased toward the caliper, effectively preventing the coil spring from coming out when the brake lever rotates in the direction of braking action.

〔Example〕

Hereinafter, an embodiment in which the vehicle disc brake device according to the present invention is applied to a parking brake mechanism of a hydraulic disc brake device equipped with an auto-adjust mechanism will be described with reference to FIGS. 1 to 4.

The caliper 10 of the hydraulic disc brake consists of an acting part 10a, a reaction part 10b, and a bridge part 10c connecting these parts.The bridge part 10c straddles the disc 11, and the sliding pin 13 on the bracket 12 allows the caliper to move in the axial direction of the disc. It is provided.

Further, the actuating portion 10a is formed with a cylinder 14 which is open on the disk 11 side, and a cup-shaped piston 15 is fitted into the cylinder 14 in a fluid-tight and movable manner. A hydraulic pressure chamber 16 is defined therein, and an introduction hole 17 for introducing pressure fluid from a master cylinder (not shown) opens into this hydraulic pressure chamber 16 .

Friction pads 18 are provided on both sides of the disk 11,
One friction pad 18 on the side of the piston 15 is pushed by the piston 15 and comes into pressure contact with one side of the disk 11, and the reaction force acting on the piston 15 causes the caliper 1 to move.
0 moves to the acting portion 10a side, and the caliper 1
The reaction part 10b of 0 pushes the other friction pad 19 into pressure contact with the other side of the disk 11, and the disk 11 is clamped between the two friction pads 18 and 19 to perform braking by hydraulic pressure operation.

In the hydraulic pressure chamber 16, an adjusting bolt 20 is provided.
and an adjuster nut 21 screwed onto the adjuster bolt 20 with a multi-thread screw.The adjuster 22 uses a spring to move the adjuster nut 21 toward the disk 11 and the adjuster bolt 20 back through a bearing. Each is biased toward the disk side.

Further, the adjusting nut 21 is connected to the piston 1.
The adjustment bolt 20 engages with the disk 11 side of the cylinder 14 to restrict its rotation, and the adjusting bolt 20 has a clutch portion 20a formed on its head, and a sleeve piston 23 that is fitted into the rear part of the cylinder 14 so as to be movable in the axial direction.
When the piston 15 moves more than a predetermined distance due to wear of the friction pads 18 and 19, the friction engagement of the clutch portion 20a of the adjusting bolt 20 is released and the adjusting bolt 20 rotates. By extending the entire length of the adjuster 22, the return position of the piston 15 is changed closer to the disk 11, and an appropriate braking gap is automatically adjusted.

On the other hand, the sleeve piston 23 has a piston small diameter portion 23a formed at its rear portion that is fluid-tightly fitted into the small diameter portion 14a of the cylinder 14, and one end of the driven rod 24 is engaged with the rear end surface of the piston small diameter portion 23a. A spherical recess 23b for matching is formed.

Further, on the opposite side of the hydraulic pressure chamber of the small diameter portion 14a of the cylinder 14, a cylindrical bearing portion 25 for fitting the camshaft is formed in a direction perpendicular to the cylinder axis so as to communicate with the small diameter portion 14a. A cylindrical camshaft 26 is rotatably fitted into the bearing part 25 for fitting and inserting the camshaft via a bearing 27, and a cam groove 26a formed on the side surface of the fitting part of the camshaft 26 is provided with the driven rod. The other end of 24 is engaged.

Further, a lever mounting portion 26b is formed in a portion of the camshaft 26 extending from the bearing portion 25, and a brake lever 28 for rotating the camshaft 26 is fastened to this lever mounting portion 26b with a long nut 29. A coil spring 30 is wound around the outer periphery of the long nut 29 in a loosely fitted manner.

The coil spring 30 has one end 30a locked to the tip of the brake lever 28, and the other end 30b locked to the caliper 10.
The camshaft 26 is located near the camshaft 26 of
The brake lever 28 is engaged with a stopper pin 31 that stands upright parallel to the brake lever 28, and uses the elastic force in the torsional direction to bias the brake lever 28 in the counter-braking motion direction (direction of arrow A).

The stopper pin 31 has a head 31 at its tip.
a, a flange 31b having a large diameter is formed at an intermediate portion of the flange 31b, spaced apart from the head 31a;
The surface of the brake lever 28 on the side opposite to the caliper comes into contact with the surface of the flange 31b on the side of the caliper 10 to prevent the brake lever 28 from floating, and the head 31a of the stopper pin 31
An engagement groove 31c for engaging the end portion 30b of the coil spring 30 is formed between the flange 31b and the flange 31b.

The end portion 30b of the coil spring 30 that is engaged with the engagement groove 31c is connected to the stopper pin 31.
The engagement groove 31c is bent into a U-shape toward the side opposite to the stopper pin with a curvature slightly larger than the shaft diameter of the engagement groove 31c, and the proximal straight portion 30 of the U-shaped end 30b is formed.
c toward the opposite side of the caliper, and furthermore, the distal side straight portion 30d at the tip of the U-shaped curved portion of the end portion 30b is also bent toward the opposite side of the caliper with an inclination in the opposite direction to the inclination of the proximal side straight portion 30c. The engaging groove 31c is loosely fitted into the inner surface of the U-shaped end 30b, and the straight portion 30c on the tip side is connected to the head 31a of the stopper pin 31 on the caliper 10 side. When the brake lever 28 is in the position shown by the solid line in FIG. 4 during non-braking operation, that is, when the brake lever 28 is in the initial position, the coil spring 30 Said U-shaped end 3
0b engages only the inner side of the proximal straight portion 30c of the U-shaped portion by the torsional elastic force of the coil spring 30 into the engagement groove 31 of the stopper pin 31.
c, a gap is formed between the bent portion of the U-shaped end 30b and the bottom of the engagement groove 31c, and the brake lever 28 is pulled by a brake wire (not shown). coil spring 30
The end of the coil spring 30 when it rotates in the braking action direction (arrow B direction) against the torsional elastic force of the coil spring 30, that is, when it rotates to the position shown by the two-dot chain line in The coil spring 30 allows the coil radial movement of the portion 30b, and the coil spring 30 is formed by bending the end portion 30b locked in the engagement groove 31c toward the opposite side of the caliper, so that the head portion 31a of the stopper pin 31 is bent. The elastic force generated by the torsion force of the distal straight portion 30d and the proximal straight portion 30d pressed against the surface opposite to the caliper constantly urges the caliper toward the caliper, and when the brake lever 28 rotates during braking operation. , the coil spring 30 is connected to the long nut 2
It is locked to prevent it from slipping out from the outer periphery of 9.

In addition, 32 is a bolt 32a, 32 attached to the caliper 10.
The brake wire guide is attached by a, 33 is a dustproof boot, and 34 is a brewer plug.

With the above configuration, when the brake lever 28 rotates during braking operation, the coil diameter of the coil spring 30 is reduced, and the entire coil spring 30 moves in the opposite direction to the stopper pin 31, the coil spring 30 is formed into a U-shape by the elastic force in the torsional direction.
is brought into pressure contact with the bottom of the engagement groove 31c of the stopper pin 31, and the straight portion 30d on the tip side is pressed against the bottom of the engagement groove 31c of the stopper pin 31.
The coil is brought into pressure contact with the surface on the opposite side of the caliper 1a and slid in the radial direction of the coil while being constantly biased toward the caliper 10 by the elastic force generated by the torsion force of the distal straight portion 30d and the proximal straight portion 30c, Stress concentration on the end portion 30b is prevented, and movement of the coil spring 30 in the withdrawal direction is effectively prevented.

Furthermore, although this embodiment has been described as an example in which it is applied to a parking brake mechanism of a hydraulically actuated disc brake device, the present invention can also be applied to other types of disc brake devices, such as those in which braking is performed only by a mechanical actuation mechanism. It can be suitably implemented.

[Effect of idea]

As explained above, the vehicle disc brake device according to the present invention has a brake lever attached to a camshaft, which is wrapped around the outer periphery of the camshaft, and one end is locked to the brake lever and the other end is locked to a stopper pin. The coil spring is biased in the direction of counter-braking motion by the torsional elastic force of the coil spring, and the end of the coil spring that engages with the stopper pin is formed into a U-shape, and the U-shaped end is directed toward the opposite side of the caliper. The coil spring is arranged so that it can move in the coil radial direction with this end pressed against the caliper-side surface of the large-diameter head at the tip of the stopper pin, so that the brake lever does not move during braking operation. The end of the coil spring locked to the stopper pin does not come off even when rotated, prevents stress concentration on the end, and prevents the coil spring from moving in the direction of withdrawal, ensuring smooth mechanical operation. It has the effect of ensuring. In addition, the brake lever is pushed toward the caliper by the pressure of the U-shaped end bent toward the opposite side of the caliper against the large diameter portion of the stopper pin tip, so that movement of the camshaft in the axial direction can be restricted. Furthermore, when the brake lever rotates, the coil spring is twisted and tends to fall in the axial direction of the camshaft, but the U-shaped end is in pressure contact with the large diameter part of the stopper pin tip. Since a force acts to return the coil spring in the opposite direction, the coil spring is prevented from falling, and the camshaft is also prevented from twisting.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a side view showing the entire disc brake device, FIG. 2 is a plan view, and FIG. 3 is a cross-sectional view of FIG. Fig. 4 is a front view of the main part showing the brake lever mounting part of the mechanical actuation mechanism, and Figs. 5 and 6 are main parts showing the brake lever mounting part of the mechanical actuation mechanism in a conventional disc brake device, respectively. It is a front view. 10...Calipa, 11...Disk, 14...
... Cylinder, 15 ... Piston, 16 ... Hydraulic pressure chamber, 18, 19 ... Friction pad, 22 ... Adjuster, 24 ... Driven rod, 25 ... Bearing part, 2
6...Camshaft, 26a...Cam groove, 28...
...Brake lever, 30...Coil spring,
30a, 30b... end, 30c... proximal straight part, 30d... distal straight part, 31... stopper pin, 31a... head, 31b... flange, 3
1c...Engagement groove.

Claims (1)

[Scope of utility model registration request] A brake lever is attached to the camshaft so that a camshaft, in which a friction pad that presses against a brake disc to perform braking is inserted into a bearing of a caliper, is rotated and mechanically pushed to perform a braking action. The coil spring is wound around the outer periphery of the brake lever and is biased in the direction of counter-braking action by the torsional elastic force of a coil spring whose one end is locked to the brake lever and the other end is locked to a stopper pin installed upright on the caliper. In the disc brake device for a vehicle, the fixed end portion of the coil spring that is engaged with the stopper pin is formed in a U-shape, and
A stopper pin with a letter-shaped end bent toward the opposite side of the caliper and a large-diameter head formed at the tip is installed upright on the caliper, and the U-shaped end of the coil spring is connected to the stopper pin. The coil is latched to allow movement in the radial direction of the coil, and the U-shaped end is arranged so as to press the caliper side surface of the large diameter head of the stopper pin. Disc brake device.