JPS6221790Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a caliper device for a disc brake that has an adjusting mechanism in the cylinder.

[Prior art]

This type of disc brake device is capable of hydraulic operation from the master cylinder and mechanical operation using mechanical force from a handbrake, etc., and its adjust mechanism adjusts according to the displacement of the piston. A hydraulic chamber is defined in the cylinder by the cylinder and the piston so as to perform
This piston is engaged with a braking member that is movable in the axial direction and whose rotation is regulated to regulate the rotation of the piston, and an adjustment bolt and a nut member screwed therein are connected to the hydraulic pressure chamber. The nut member engages with the piston to restrict its rotation and is biased in the direction of the piston by a first spring, while the adjuster bolt is rotatable to the cylinder and is biased toward the piston by a second spring. The adjusting bolt is biased toward the rear of the cylinder, and the rear end of the cylinder engages in a clutch with the large-diameter end of a sleeve piston having a large-diameter portion and a small-diameter portion, and the small-diameter portion of the sleeve piston The end is in contact with a rod that is operated by mechanical operation, but the disc brake caliper device with the above structure takes many steps to completely bleed air from the hydraulic pressure chamber when filling the hydraulic fluid. It was time consuming.

[Purpose of invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a caliper device for a disc brake that allows air to be easily vented from a cylinder hydraulic chamber during a hydraulic fluid filling operation.

[Structure of the idea]

In order to achieve the above object, in the present invention, an appropriate number of pins implanted at the rear end of the large diameter portion of the sleeve piston are engaged with the inner wall of the hydraulic chamber to restrict rotation. A part of the rear end of the large diameter part,
The present invention is characterized in that an arcuate groove is formed leaving the pin installation portion, and a liquid passage hole for introducing pressure liquid from a hydraulic pressure source is opened at a position facing this groove.

〔Example〕

Next, an embodiment of a disc brake caliper device according to the present invention will be described with reference to the drawings.

The caliper 1 consists of an actuating part 1a, a counter-actuating part 1b, and a bridge part 1c connecting these parts.The caliper 1 straddles the disk 2 by the bridge part 1c and is provided on a bracket 3 so as to be movable in the disk axial direction. The actuating part 1a includes a cylinder 4 that is open on the disk 2 side.
is formed, and the large diameter portion 4a of this cylinder 4
Inside is a tip-shaped piston 5 with a piston seal 6.
A hydraulic chamber 7 is defined within the cylinder 4, and a liquid passage hole 8, which will be described later, is provided in the hydraulic chamber. Friction pads 9, which are braking members, are provided on both sides of the disc 2.
9' is arranged, and the friction pad 9 on this cylinder side
is supported by the bracket 3 so as to be movable in the axial direction of the disk, but its rotation is restricted, and the other friction pad 9' is engaged with the reaction portion 1b.

The head 5a of the piston 5 is formed with recesses 5b at a suitable number of locations, and the recesses 5b are fitted into corresponding recesses 9b formed in the back plate 9a of the friction pad 9. 5a is in contact with the back plate 9a. As a result, the piston 5 pushes the friction pad 9 in the disk axial direction, but its rotation is restricted by the friction pad 9.

An adjuster 12 consisting of an adjuster bolt 10 and an adjuster nut 11 is built in the hydraulic chamber 7, and the adjuster nut 11 has a multi-thread internal thread 11a.
A multi-thread male screw 10a is formed in each of the small-diameter shaft portions of 0, and both 11a and 10a are screwed together with a multi-thread screw with a small screwing gap.

The adjustment nut 11 is engaged with the piston 5 with a press-fit pin 11c press-fitted into the head 11b fitted into an air vent groove 5e provided at the bottom 5d of the piston 5 to restrict rotation.

Further, the head 10b of the adjusting bolt 10 is provided with a communication hole 10d for supplying the hydraulic oil in the hydraulic pressure chamber 7 to the tapered clutch portion 10c, and the tip of the adjusting bolt 10 is sealed by a cup seal 10e as described below. Large diameter portion 13a of sleeve piston 13
It is fluid-tightly and rotatably fitted inside.

Reference numeral 13 denotes a sleeve piston, the large diameter portion of which is inserted into the hydraulic pressure chamber 7 of the cylinder 4, and the small diameter portion 13 of the sleeve piston.
b are located within the cylinder small diameter portion 4b, respectively. The sleeve piston also has two pins 13c implanted at the rear end of its large diameter portion.
13d is the rear end bottom 4c of the large diameter portion 4a of the cylinder 4.
They are fitted into locking holes 4d drilled in the cylinder 4, respectively, and are provided so as to be slidable in the axial direction of the cylinder 4 while being restricted from rotating.

Moreover, the large diameter portion 13 of this sleeve piston 13
On the rear end side of a, an arc-shaped groove 13 is formed leaving implanted portions 13e and 13f where the pins 13c and 13d are implanted.
g, 13h are formed, and the arc-shaped groove 13
The liquid passage hole 8 introduces pressurized liquid from a master cylinder (not shown) into a position facing a part of the cylinders g and 13h.
has been established.

Further, the large diameter portion 13a of the sleeve piston 13
The head 10 of the adjusting bolt 10 is attached to the end face of the adjusting bolt 10.
There is provided a hollow cylindrical portion 13i into which the cylindrical portion b is fitted, and a tapered clutch surface 13j is formed at the opening edge of this hollow cylindrical portion 13i.

One end of the first spring 14 wound around the shaft of the adjusting nut 11 is attached to the head 11b of the adjusting nut 11, and the other end is attached to the spring receiver stopper 15 fitted in the annular groove 5g on the inner periphery of the cylindrical portion 5f of the piston 5. The adjusting nut 11 is urged toward the piston, and the front surface of the head 11b is in contact with the inner surface of the piston 5. An air exhaust groove 17, which is deeper than the annular groove 5g, is formed on the inner surface of the cylindrical portion 5f of the piston 5 so as to straddle the annular groove 5g in the axial direction of the piston. This makes it easier to discharge.

A brewer hole 19 is opened in the hydraulic pressure chamber 7, and a circumferential groove 20 is provided across the brewer hole 19 on the inner peripheral surface of the large diameter portion 4a of the cylinder 4. A retainer 22 is provided by locking a proximal end flange portion 22 a to a ring-shaped retainer stopper 21 .
The cylinder 4 is biased toward the rear by a conical second spring 18 whose large-diameter end is locked to the cylinder 2b and whose small-diameter end abuts against the head 10b via a bearing 23. .

The small diameter portion 13b of the sleeve piston 13 is surrounded by a seal ring 24, and is fitted in the cylinder small diameter portion 4b in a fluid-tight and slidable manner.

A cylindrical rear wall 1d is formed on the side opposite to the hydraulic pressure chamber of the cylinder small diameter part 4b, and is integrally connected to the actuating part 1a so as to be perpendicular to the cylinder small diameter part 4b and communicate with the cylinder small diameter part 4b. , a camshaft 25 has a bearing 26 on the inner surface of this rear wall 1d.
It is rotatably inserted through the intervening .

The conical recess 27 formed in the end face of the small diameter portion 13b of the sleeve piston 13 and the camshaft 2
A push rod 29 is interposed between the cam groove 28 and the cam groove 28 formed in the axial direction of the push rod 5. This push rod 29 has both ends formed into a spherical shape, and is pushed by the rotation of the camshaft 25 to push the sleeve piston 13 in the braking direction.

Further, an atmospheric communication hole 13k communicating with the hollow cylindrical portion 13i of the large diameter portion 13a is bored at the innermost part of the conical recess 27 of the sleeve piston 13 into which one end of the push rod 29 is fitted. The conical recess 27 side of the atmosphere communication hole 13k is closed by the working end of the push rod 29 to allow ventilation.

Next, the operation of this embodiment will be explained.

When the pressure fluid from the master cylinder is introduced into the hydraulic chamber 7 through the fluid passage hole 8, the piston 5 moves to the left in FIG. As a result, the caliper 1 moves in the opposite direction to the right, and the reaction part 1b presses the other friction pad 9' toward the other side of the disk 2, thereby producing a braking action.

At this time, as the piston 5 moves forward, the adjusting nut 11 also moves forward together with the first spring 14, but the amount of movement of the adjusting nut 1
1 multi-thread female screw 11a and adjustment bolt 10
This is the amount of backlash that fills the gap between the threaded male screw 10a and the multi-thread male screw 10a, and since no axial force is generated that acts on the threaded portion of the multi-thread screw, no rotational torque is generated, and therefore the adjuster bolt 10 rotates. The braking action is carried out without any friction.

When the friction pads 9, 9' are worn out and the braking gap becomes larger than the set value, when a braking action is performed, the amount of movement of the piston 5 is determined by the gap between the adjustment nut 11 and the adjustment bolt 10 in which the multi-thread screw is engaged. , the adjusting nut 11 and the adjusting nut 10 move forward together, and the head 10b of the adjusting bolt 10 attempts to separate from the large diameter portion 13b of the sleeve piston 13, and at this time, the sleeve piston 13 communicates with the atmosphere. Atmospheric air is introduced through the hole 13k, and the air is smoothly separated, and an axial force is applied to the multi-thread threaded portion due to the hydraulic pressure in the hydraulic chamber 7. This axial force rotates the adjuster bolt 10, and the adjuster 12 expands, and the clutch portion 10c of the adjusting bolt 10 re-engages with the clutch surface 13j of the large diameter portion 13a of the sleeve piston 13, stopping rotation and achieving automatic adjustment of the braking gap. When the adjuster 12 expands, the clutch portion 10c of the adjuster bolt 10 rotates and slides into contact with the clutch surface 13f of the large diameter portion 13a of the sleeve piston 13. Since the diameter of the clutch surface is large, a large frictional resistance is obtained. Instantly stop the rotation of the adjustment bolt 10,
Reliably prevent over-adjustment. and,
When the supply of pressure fluid stops and the master cylinder piston (not shown) returns due to the action of the return spring, the hydraulic pressure in the hydraulic chamber 7 of the cylinder 4 decreases, and the piston 5 is returned to its original position by the piston seal 6. He tries to return, but the adjuster 1 stretches out.
2, and the braking gap between the disc 2 and the friction pads 9, 9' is automatically adjusted to be always constant.

Next, the handbrake action will be explained.

When you pull the handbrake lever (not shown),
In response to the mechanical force, the camshaft 25 rotates counterclockwise in FIG. 1, pushing the rod 29 to the left, and thereby the piston 5 is pushed by the adjuster 12 via the sleeve piston 13 and moved to the left. Move forward to the disk 2 and place one friction pad 9 on the disk 2.
Press it to one side, and this reaction will cause the caliper 1 to
moves to the right in the opposite direction, and the other friction pad 9'
to the other side of disk 2 to apply the handbrake.

At this time, one spherical end of the push rod 29 pushes the sleeve piston 13 toward the adjuster bolt 10.
When pressed against the head 10b of the sleeve piston 13, the clutch surface 13j of the sleeve piston 13 and the adjuster bolt 10
Since the frictional resistance between the clutch portions 10c increases, the adjusting bolt 10 does not rotate. Therefore, the state of the multi-thread screw engagement between the nut member 11 and the adjuster bolt 10 does not change, and the adjuster 12 can perform braking by mechanical operation without shrinking.

[Effect of the invention]

As described above, the present invention engages the hydraulic chamber wall with an appropriate number of pins implanted in the rear end of the large diameter portion of the sleeve piston to restrict rotation, and also controls the rotation of the sleeve piston at the rear end of the large diameter portion. A circular groove is formed by leaving a part of the pin installation part, and a liquid passage hole is opened facing this groove to introduce the pressure liquid from the hydraulic pressure source, so that the hydraulic pressure of the cylinder is reduced. The air present around the sleeve piston arranged in the chamber can be easily discharged by filling the chamber with hydraulic fluid.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional front view showing an embodiment of the present invention;
FIG. 2 is a cross-sectional view of FIG. 1. 1 is a caliper, 4 is a cylinder, 4d is a locking hole,
5 is a piston, 7 is a hydraulic chamber, 8 is a liquid passage hole, 9,
9' is a friction pad, 10 is an adjustment bolt, 1
1 is an adjustment nut, 13 is a sleeve piston, 13c, 13d are pins, 13e, 13f are implanted portions, 13g, 13h are arcuate grooves, 14 is a first spring, 18 is a second spring, 19 is a brewer hole, 22 is a retainer, 25 is camshaft,
28 is a cam groove, and 29 is a push rod.

Claims (1)

[Scope of utility model registration request] In the hydraulic pressure chamber defined by the actuation piston fitted in the cylinder of the actuating part of the caliper, there are an adjustment nut and an adjustment bolt fitted with a multi-thread screw of the automatic braking gap adjustment device, and a sleeve that transmits the mechanical actuation force. A large diameter portion of the piston is disposed, the adjusting nut is biased in the braking direction by a spring, and the adjusting bolt is inserted between the head of the adjusting bolt and a retainer whose base end is fixed to the inner periphery of the hydraulic pressure chamber. The contracted spring urges the sleeve piston in the anti-braking direction, and the sleeve piston engages the inner periphery of the hydraulic pressure chamber with its large diameter portion to restrict rotation and is slidably provided. A braking action is performed by the pressure fluid supplied from the opening fluid passage hole, and the other end of the sleeve piston is fitted into the working end of a push rod operated by mechanical operation, and the sleeve piston is pressed by the operation of the push rod. In a disc brake caliper device that performs a braking action by pushing the actuating piston through the braking gap automatic adjustment device, the sleeve piston is provided with an appropriate number of pins implanted at the rear end of a large diameter portion of the sleeve piston. is engaged with the inner wall of the hydraulic pressure chamber to restrict rotation, and at the same time, an arc-shaped groove is formed in a part of the rear end of the large-diameter part, leaving the pin-embedded part, and a groove facing this groove is formed. A caliper device for a disc brake, characterized in that a fluid passage hole is provided at a position for introducing pressure fluid from a fluid pressure source.