JPS5821033A - Brake cylinder device for vehicle - Google Patents

Abstract

PURPOSE:To surely perform adjusting action also effectively prevent overadjustment, by arranging an adjuster not extensible at fluid pressure except a preset level in a pressure fluid chamber. CONSTITUTION:If high pressure fluid is fed to a pressure fluid chamber 7, pressing force to an adjusting bolt 10 rightward is increased, and a recessed part 21 of an adjusting bolt head part 10b is strongly contacted to a spherical part 23a of a rod 23 to increase friction resistance. In this way, friction resistance, limiting rotary movement of the adjusting bolt 10, becomes larger than rotary torque, and the adjusting bolt 10 can not be rotated. Further a protrusive stripe 11c in a head part 11b of a nut member 11 is set in such a manner as not to be disengaged from a grooved part 5d of a piston 5, and the nut member 11 is never rotated to perform adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle brake cylinder device having an adjustment mechanism within the cylinder.

Conventional vehicle brake cylinder devices of this type are capable of hydraulic operation from the mask cylinder and mechanical operation using mechanical force from the handbrake lever, and the adjustment mechanism is based on the displacement of the piston. It is configured to make adjustments accordingly. Therefore, when high hydraulic pressure is applied to the cylinder, causing deformation of the brake system components and excessive displacement of the piston, the adjustment mechanism adjusts the braking gap by including the displacement of the piston. There is a danger that the piston will not be able to return due to so-called over-adjustment, and the braking member such as the friction pad will drag.

Therefore, in order to avoid this, it is necessary to provide extra play in the adjustment mechanism to prevent excessive displacement of the piston, and this extra play may cause problems such as increasing the invalid stroke of the handbrake lever. Ta. For this reason, the braking gap is adjusted according to the displacement of the piston, but there are some systems that prevent over-adjustment by preventing the adjustment from being made when the pressure fluid in the cylinder exceeds a predetermined value. Over-adjustment cannot be prevented, and it is necessary to provide many hydraulic seals, which causes liquid leakage. Moreover, the structure is complicated and the number of parts increases.

A feature of the vehicle brake cylinder device of the present invention is that an adjuster consisting of an adjustment bolt and a nut member screwed onto the adjuster bolt is built into the cylinder, and this nut member engages with the piston in a convex-concave manner to restrict rotation. The first spring biases the adjustment bolt toward the disk, while the second spring biases the adjustment bolt toward the rear of the cylinder. By placing the multi-thread threaded part of the adjustment mechanism on the piston side, which rotatably abuts, and the clutch part, which rotates or restricts rotation depending on the hydraulic pressure, at the rear of the cylinder, the action is reliable and over-adjustment is also effective. To provide a brake cylinder device for a vehicle which solves the above-mentioned problems, has a small number of hydraulic seals, has a simple brake structure, reduces the number of parts, and is easy to manufacture and assemble.

A caliper 1 will be described below based on an embodiment in which the present invention is applied to a disc brake with reference to the drawings.The caliper 1 is composed of an actuating part 1a, a reaction part 1b, and a bridge part 10 connecting these parts. It is provided on the bracket 3 so as to be movable in the axial direction of the disk. There are two discs in the operating part 1a.
An open cylinder 4 is formed, and this cylinder 4
A tip-shaped piston 5 is tightly and slidably fitted in the large diameter portion 4& of the cylinder 4 by a piston seal 6, thereby defining a hydraulic chamber 7 within the cylinder 4, and a master cylinder 7 (not shown). ) A pressurized liquid is supplied into the hydraulic pressure chamber 7 through the liquid passage hole 8 communicating with the hydraulic pressure chamber 7 . Friction pads 9 and 9', which are braking members, are arranged on both sides of the disc 20, and this cylinder-side friction pad 9 is supported by the bracket 3 so that it can move in the disc axial direction but restricts its rotation. The pad 9' engages with the reaction part 1b.

The head 5a of the piston 5 has recesses 5b formed at appropriate locations, and the recesses 5b fit into corresponding projections 9b formed on the back plate 9a of the friction pad 9. , the head 5a is in contact with the back plate 9a. This allows piston 5
The friction pad 9t is pushed in the disk axial direction, but its rotation is restricted by the friction pad 9. An adjuster 12 consisting of an adjustment bolt 10 and a nut member 11 is built into the hydraulic pressure chamber 7. The nut member 11 has a multi-thread female thread 11a, and the small diameter shaft of the adjustable bolt 10 has a multi-thread male thread 10a. Screwed together.

A protruding line 110 is formed in the radial direction on the lower side of the head 1ik) of this nut member 11, and the protruding line 110 is formed on the lower side of the head 1ik) of the nut member 11.
The nut member 110 engages with the lower structural part of the groove part 5d formed radially from the hole part 50 bored at the center of the nut member 110.
The head 11b is in contact with the inner surface of the piston 5, and the tip of the adjustment bolt 10 is fitted with a play so as not to interfere with the hole 5ciC'' piston 5.Thereby, the nut member 11 is attached to the piston 5. Rotation is regulated by
In addition, the upper groove part where the convex itc formed on the inner surface of the piston 5 is not fitted becomes the air release passage 13, and when assembled, the multi-thread screws 10a, 111! Air accumulated in L, hole 5C, etc. can be reliably removed.

One end of the first spring 14 wound around the shaft of the nut member 11 is attached to the head 11b of the nut member 11, and the other end is attached to the piston 7.
50 The spring seat 16 is heated by the seat stopper 15 fitted in the annular groove 5f on the inner periphery of the cylindrical portion 5e, thereby urging the nut member 11 in the direction of the piston, and the head 1 of the nut member 11 is urged toward the piston.
The front surface of 1b is in contact with the inner surface of piston 5. An air exhaust groove 17 deeper than the annular groove 5f is formed on the inner surface of the cylindrical portion 5e of the piston 750, and an annular groove 5ft extends in the axial direction of the piston.
- The piston 5 is formed so as to straddle the piston 5 to facilitate the discharge of air accumulated on the inner surface of the piston 5 during assembly.

The head 10b of the adjustment bolt 10 is tightly fitted into the small diameter portion 4bK cup 18 of the cylinder 4 so as to be slidable and rotatable.

A cylindrical rear portion 11 is provided at the rear of this cylinder small diameter portion 4b.
1 (1) is formed perpendicularly to the small diameter portion 4b and integrally with the operating portion 1 & communicates with the small diameter portion 4b, and the camshaft 19 is connected to the rear wall 1d via two large and small bearing rings 20. are rotatably fitted.

A rod 23 is interposed between the concave portion 21 formed in the adjustment port 1of)il1 portion lob and a nine cam groove 22 formed in the axial direction of the camshaft 19. This rod 23 has a spherical shape on the adjustment bolt side and a wedge shape on the camshaft side.Thereby, the rod 23 allows the adjustment bolt 10 to rotate, but the cam groove 22 restricts the rotation of the rod 23 itself. is pushed by the rotation of the camshaft 19 and the adjustment bolt 1 (1-
It is possible to convert the rotation of the pushing camshaft 19 into a propulsive force in the braking direction. In the recessed part 21 of the adjustment bolt head 10b, a grease discharge passage 21a is connected to the rear chamber 24 from the bottom.
The rod 23 is formed in a groove shape and communicates with the rod 23 when assembled.
This prevents grease from being sealed between the spherical part 23a and the bottom of the four parts 21, thereby ensuring reliable clutch action.

Small diameter straight shaft portion 100 of the adjustment bolt 10
One end of the second spring 25 wound around the cylinder is connected to the retainer 26 which is attached to the mouth end of the cylinder small diameter part 4b by locking the 7 rank part 26SL, and the other end is connected to the head 10k) through the bearing 27t. As a result, the adjustment bolt 10 is urged toward the rear of the cylinder. The retainer 26 has a guide portion 21b formed by folding back the small diameter straight shaft portion 100 side along the shaft portion.
6b and the small-diameter straight shaft portion 100 is reduced to prevent vibrations when the adjustment bolt 100 slides, thereby preventing any adverse effects on the cylinder 4.

A lever 28 is fixed to the base 19a of the camshaft 19 by a nut 29. When the lever 28t is rotated in the inward direction in FIG. 3, the camshaft 19 is rotated counterclockwise in FIG. When the brake is applied and the brake is released, the return spring 30 rotates in the direction B and returns to the original position.

Next, the operation of this embodiment will be explained.

Pressure liquid from the mask cylinder passes through the liquid passage hole st to the liquid pressure chamber 7.
2, the piston 5 moves to the left in FIG. 2 and presses one friction pad 9 against one side of the disc 2, which causes the caliper 1 to move in the opposite direction to the right. As it moves, the reaction part 1b presses against the other side of the other friction pad s/l disk 2, and a braking action is performed.

Assuming that the hydraulic pressure at this time is P, the nut member 11 also moves forward together with the first spring 14 as the piston 5 moves forward, but the amount of movement is the same as that of the multi-thread internal thread (ll&) of the nut member 11 and the adjustment pole (10). Multi-start male thread 10
This is the amount to deepen the threaded engagement gap with the multi-threaded screw, and since no axial force is generated on the threaded part of the multi-thread thread, no rotational torque is generated, and therefore the adjustment bolt 10 does not rotate and has no braking action. It is done.

Then, when the hydraulic pressure P, a higher hydraulic pressure P, is supplied into the hydraulic pressure chamber 7, the nut member 11 maintains a state of engagement with the piston 5 and moves forward together with the piston 5, so that the nut member 11 and the adjustment bolt Multi-thread screw engagement with 10 - there is no gap, and even higher hydraulic pressure P is generated to the right (Adjust Pol)
10t - A force moving to the right is generated, and an axial force is generated in the multi-thread threaded portion, and this axial force generates a rotational torque. This rotational torque becomes a force that tends to rotate the adjustment bolt 10 because the nut member 11 engages with the piston 5 in a concave and convex manner and its rotation is restricted.

The force that tries to restrict the rotation of the adjustment bolt 10 at this time, that is, the frictional resistance between the cylinder small diameter portion 4b, the head 10b of the adjustment bolt 10, and the cup 18, and the recess 21 of the head 10b and the rod 23 The frictional resistance between the adjusting bolt 10 and the spherical portion 21a is extremely small, and the rotational torque generated by the hydraulic pressure a is set to be larger than these frictional resistances, so the adjustment bolt 10 rotates.
The screwing state between the nut member 11 and the adjustment bolt lO changes, and the adjuster 12 expands. Then, when the supply of pressure fluid is released, the piston 5 attempts to return to its original position due to the piston seal 6, but the piston 5 expands and the nine adjuster 12
The braking gap between the disc 2 and the friction pad 9,9' is automatically adjusted to be constant at all times.

Next, when the hydraulic pressure P1, which is even higher than the hydraulic pressure P, is supplied into the hydraulic pressure chamber 7, the nut member 11 and the adjustment bolt 1
0, rotational torque is generated by the axial force acting on the multi-threaded threaded portion with P.
In the figure, the pressing force to the right increases, and the concave portion 21 of the adjustment bolt head 10b is pressed against the spherical portion 2 of the rod 23.
3a, and the frictional resistance increases. As a result, the shear adjustment bolt 10, whose frictional resistance that attempts to restrict the rotation of the adjustment bolt 10 is greater than the rotational torque, rotates and becomes a bottle.

Since the nut member 11 is engaged with the piston 5 in a concave and convex manner, even if the hydraulic pressure P is high or the caliper 1 etc. is deformed at this time, the nut member 11 does not rotate and only the piston 5 engages the first spring 14. Compress and move forward. As a result, the inner surface of the piston 5 and the head portion 11b of the nut member 11
Although a gap is generated between the nut member 11 and the groove 5d of the piston 5, the nut member 11 does not rotate and adjust because the convex ridge 110 of the head 11b is set so as not to disengage from the groove 5d of the piston 5.

In this way, even if a high hydraulic pressure P is supplied into the hydraulic pressure chamber 7 and the piston 5 moves out of the cylinder 4 excessively due to deformation of the cylinder lipper 1, etc., the hydraulic pressure P, Since the adjuster 12 does not extend at pressures other than the set pressure, excessive adjustment including deformation of brake components such as deformation of the caliper 1 is prevented. There is no need to provide extra play for the excessive advance of the lever, and the invalid stroke of the handbrake lever when the handbrake is applied can be reduced.

Next, the handbrake action will be explained.

When the handbrake lever (not shown) is pulled, the lever 28 receives mechanical force and rotates in the inward direction in FIG. 3. As a result, the camshaft 19 rotates counterclockwise in FIG. 2, and due to this reaction, carino < 1
moves in the opposite direction to the right and presses the other friction rod 9' against the other side of the entire disk 2, applying the 71st brake.

At this time, the spherical portion 231L of the rod 23 presses the recess 21 of the adjustment bolt head 10b, and both
Since the frictional resistance between the two increases, the adjustment bolt 10
never rotates. Therefore, the state of threaded engagement between the nut member 11 and the adjustment bolt 10 does not change;
The adjuster 12 never shrinks.

Although the above embodiment has been described as a cylinder device for a disc brake, the present invention is not limited thereto, and can be widely applied to other vehicle brake cylinder devices such as a wheel cylinder of a drum brake.

As explained above, the present invention has a multi-threaded threaded part of the 9 adjustment mechanism built in the cylinder on the piston side, and a clutch part that rotates according to the hydraulic pressure and whose rotation is regulated in the 9 adjustment mechanism at the rear of the cylinder. Therefore, the adjustment mechanism can extend according to the displacement of the piston to reliably adjust the braking distance, and it also prevents changes in the parts that make up the disc brake or drum brake, or excessive hydraulic pressure in the cylinder. is supplied to prevent the adjustment mechanism from over-adjusting even if the piston is displaced. Furthermore, this eliminates the need to provide extra play in the adjustment mechanism to prevent excessive displacement of the piston, and reduces the invalid stroke of the handbrake lever. In addition, compared to conventional models, there are fewer hydraulic seals and no liquid leakage occurs, and the structure is simple and the cylinder can be machined from one direction, making it easy to manufacture. It has the advantage of being extremely easy to assemble.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view, FIG. 2 is a side view of the section 11 in FIG. 1, FIG. 3 is a side view of the camshaft mounting part, and FIG. FIG. 3 is a partially cutaway perspective view of the shaft attachment part. 1 is a caliper, 4 is a cylinder, 5 is a piston, 7 is a hydraulic chamber, 9.9' is a friction pad, 10 is an adjustment bolt,
11 is a nut member, 12 is an adjuster, 14 is a first spring, 19 is a camshaft, 23 is a rond, 2':5
is a second spring, and 27 is a lever. Mugi 2 Ingo 4 Incho 3 Affective Procedural Amendment 1937 ux J126 Japan Patent Office Department Officer Haruki Shimada 1, Indication of the case 1982 Patent Application No. 119605 Address Nitsushin Kogyono “The rod 23 is...
. . . "At the cam groove 22" is corrected to "The rod 23 allows the adjustment bolt 10 to rotate through the spherical portion 23a, but at the wedge-shaped portion 23b."that's all

Claims (1)

[Claims] 1. A hydraulic chamber is defined in the cylinder by the cylinder and the piston, and the piston is movable in the axial direction and engaged with a braking member whose rotation is regulated to restrict the rotation of the piston. The pressure chamber has a built-in adjuster consisting of an adjustment bolt and a nine-nut member screwed with a multi-thread screw.
The nut member engages with the piston in a concave and convex manner to restrict its rotation and is biased toward the piston by a first spring, while the adjustment bolt is rotatable toward the cylinder and biased toward the rear of the cylinder by a second spring. The rear end of the cylinder of this adjustment bolt is rotatably connected to the rod, and furthermore, this rod is rotatably installed at the rear of the cylinder perpendicular to the adjustment bolt, and its rotation is regulated by the camshaft. A brake cylinder device for a vehicle, characterized in that the cylinder is engaged to be able to convert the rotation of the cylinder into a propulsion force in a braking direction.