JPH01203727A - Gap automatic regulating device for disc brake - Google Patents

Abstract

PURPOSE:To simplify assembly work, by a method wherein a piston, a regulating nut, a spindle, an adjuster piston, and a lock piston are assembled together to form a unit, which is inserted from the cylinder side. CONSTITUTION:A piston 1, a regulating nut 2, a spindle 3, an adjuster piston 7, and a lock piston 6 are assembled together to form a unit. The unit is inserted from the first cylinder 40a side. Since, during a brake liquid pressure is increased to a high value, the adjuster pin 7 is moved accompanied with the regulating nut 2, the non-rotation state of the spindle 3 is maintained to prevent the occurrence of over-regulation. This constitution facilitates assembly work.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a disc brake operated by hydraulic pressure.
Specifically, the present invention relates to an automatic gap adjustment device for a disc brake that can automatically adjust the gap between a rotating disc rotor and a friction pad that presses the disc rotor.

BACKGROUND OF THE INVENTION In general, this type of device, in addition to the function of maintaining a proper clearance between the friction pad and the disc rotor in the open state of the brake, even when the friction pad is worn, During sudden braking, etc., the caliper is elastically deformed by the reaction force from the disc rotor, and if the forward stroke of the piston that presses the friction pad exceeds the normal stroke amount regardless of friction pad wear, the friction pad and It has a function to prevent over-adjustment by stopping automatic adjustment of the gap with the disc rotor.

By the way, since such a device is configured to activate or stop the automatic gap adjustment function depending on the brake oil pressure applied to the piston, there is a problem that the number of parts increases, and the piston is Since the parts are assembled into the inserted cylinder from both sides in the axial direction of the cylinder, there is a problem in that it takes time and effort to fit the various parts, and the workability of the assembly is poor.

[Object of the Invention] The present invention has been made to solve these conventional problems, and provides an automatic disc brake gap adjustment device that can reduce the number of parts and has good parts assembly workability. The purpose is to

[Summary of the Invention] The gist for achieving the object of the present invention is to provide a first cylinder in which a piston with a bottom end for pressing a friction baffle pad against a disc rotor is housed in a cylinder body forming a part of a caliper body. At the same time, following the first cylinder, a second cylinder having a smaller diameter than the first cylinder is formed in a direction away from the rotor, and a hydraulic pressure is applied within the piston to move the piston closer to the rotor. An adjustment nut is arranged in the axial direction of the rotor, and the spindle is screwed into the adjustment nut so that the spindle can be screwed out and rotated only in the direction away from the rotor in response to the thrust in the axial direction of the rotor. an adjusting device, the second cylinder containing an adjuster piston for receiving a hydraulic action on the spindle in a direction away from the rotor and axially engaging the adjusting nut; A locking member is provided that presses against the rear end of the spindle, and the adjuster piston moves the spindle forward as the adjustment nut moves forward when the hydraulic pressure in the first cylinder is below a predetermined value. The press contact is released and the screw rotation of the spindle is allowed,
The automatic gap adjustment device for a disc brake is characterized in that, when the hydraulic pressure in the cylinder exceeds the predetermined value, the press contact is maintained and the spindle is prevented from rotating out of the way.

[Embodiments of the Invention] The present invention will be described in detail below based on an embodiment shown in FIG.

40 is a cylinder body forming a part of the caliper 41, and includes a first cylinder chamber 40a that accommodates the piston 1 formed with a bottomed front end for pressing the friction pad 42 against the disc rotor 43, and this first cylinder chamber 40a. The second smaller diameter
A cylinder chamber 40b is coaxially formed integrally with the piston 1.

Reference numeral 2 denotes an adjustment nut disposed inside the piston 1 along its axial direction, and a stopper clip 1 fixed to the piston 1.
A spring 10 interposed between the piston 1 and the piston 1 presses the tip of the spring 10 against the bottom of the piston 1 to restrict rotation.

Reference numeral 7 designates an adjuster piston with open ends that is inserted into the second cylinder 40b from the first cylinder chamber 40a side and housed therein, and an engagement flange 7a formed at the front end is fixed to the rear end of the adjustment nut 2. The web washer 9 is pressed into engagement with the engagement clip 12 .

Reference numeral 6 denotes a lock piston with a rear end and a bottom, which is housed in the adjuster piston 7, and is pressed in a direction toward the rotor by a parking rod 44 of a well-known parking mechanism.

Reference numeral 3 denotes a spindle, and a male thread formed on the front shaft part is screwed into an adjustment nut 2. This threaded part will cause the spindle 3 to rotate when a force is applied to the spindle 3 in a direction away from the rotor. It is configured to allow screwing out, and to prevent the spindle 3 from screwing in when a force is applied in a direction approaching the rotor.

Further, this spindle 3 is provided with a thrust bearing 8 on a flange portion 3a formed at the shaft end, and an overhang interposed between the thrust bearing 8 and a stopper clip 13 fixed to the front part of the lock piston 16. The travel spring 5 keeps the flange portion 3a pressed against the bottom of the lock piston 6 at all times, and when a gap is created between the flange portion 3a and the bottom of the lock piston 6, the thrust bearing 8 prevents overflow. The urging force of the travel spring 5 enables the spindle 3 to rotate.

Note that an oil seal 14 is attached to the outer circumference of the adjuster piston and the lock piston 6, respectively, so that the brake fluid pressure in the first cylinder 40a can act on the adjuster piston and the lock piston 6 in a direction away from the rotor. There is.

The structure of this embodiment has been described above, and its operation will be explained below.

Note that the brake fluid pressure supplied to the first cylinder 40a is Pl, and the spring force of the spring 10 is Fl, and the area on which the brake fluid pressure acts on the adjuster piston 7 is A1.

Brake oil is supplied into the first cylinder 40a, the backlash of the threaded portion between the adjusting nut 2 and the spindle 3 is compensated for, and the piston 1 moves forward in the left direction in the figure. that time,
Adjustment nut 2 has Fl on the left side in the figure and PA on the right side in the figure.
When the force of .

Then, the spindle 3 is rotated by the biasing force of the overtravel spring 5 until it comes into contact with the bottom of the lock piston 6, and the gap is automatically adjusted.

When the pressure is high, the adjuster piston 7 moves to the right in the figure, taking the adjusting nut 2 with it.
is maintained in a non-rotating state to prevent over-adjustment.

On the other hand, the device according to this embodiment can be easily assembled by assembling the piston 1, adjustment nut 2, spindle 3, adjuster piston 7, and lock piston 6 into a unit, and inserting this unit from the first cylinder 40a side. Assembling work becomes possible.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily process parts, and furthermore, various parts can be integrated and assembled, so that the assembly work can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. 1...Piston 2...Adjusting nut 3...
Spindle 5...Overtravel spring 6...Lock piston 7...Adjuster piston 8...Thrust bearing procedure amendment 1. Indication of the incident Patent application No. 2g31 in 1993 Name: n゛namet, -'+ nee''ti, person ifu 1ko 4, letter of attorney←和-←＋→ Amendment Specification of the application We will amend the following matters in the book and drawings. 1. The scope of claims will be corrected as shown in the attached sheet. 2. "Figure 1" in the drawings will be corrected as shown in the attached sheet. Claims: A cylinder body forming a part of the caliper body is formed with a first cylinder that accommodates a piston with a bottom at the front end that presses the friction pad against the disc rotor. A second cylinder having a smaller diameter than the first cylinder is formed in a direction away from the rotor, and an adjusting nut is provided in the piston in the rotor axial direction to be accompanied by the sliding movement of the piston in the direction toward the rotor by hydraulic action. An automatic gap adjustment device for a disc brake, in which a spindle is screwed onto the adjustment nut so that it can be screwed out and rotated only in a direction away from the rotor in response to thrust in the axial direction of the rotor, and the device is configured to apply hydraulic pressure to the spindle. On the other hand, an adjuster piston that is received in a direction away from the rotor and that engages the adjustment nut in the axial direction is accommodated in the second cylinder, and a lock that presses into contact with the rear end of the spindle is housed in the adjuster piston. When the hydraulic pressure in the first cylinder is below a predetermined value, the adjuster piston releases the pressing engagement by moving the spindle forward as the adjusting nut advances, and the screw of the spindle is released. The gap of the disc brake is characterized in that the disc brake is configured to allow the spindle to rotate outwardly, but to maintain the pressing contact and prevent the spindle from rotating outwardly when the hydraulic pressure in the cylinder exceeds the predetermined value. Automatic adjustment device.

Claims (1)

[Claims] A first cylinder is formed in a cylinder body forming a part of the caliper body, and the first cylinder accommodates a piston with a front end that presses a friction pad against a disc rotor. Subsequently, a second cylinder having a smaller diameter than the first cylinder is formed in the direction away from the rotor, and an adjusting nut is installed in the piston to be caused to slide toward the rotor by hydraulic action. An automatic gap adjustment device for a disc brake, which is arranged in the axial direction and has a spindle screwed onto the adjustment nut so that it can be screwed out and rotated only in the direction away from the rotor in response to the thrust in the axial direction of the rotor. An adjuster piston that is received by the spindle in a direction away from the rotor and that engages the adjustment nut in the axial direction is accommodated in the second cylinder, and that is pressed into contact with the rear end of the spindle within the adjuster piston. A locking member is provided, and the adjuster piston releases the pressing engagement by moving the spindle forward as the adjustment nut moves forward when the hydraulic pressure in the first cylinder is below a predetermined value. A disc brake characterized in that the screw rotation is allowed, but when the hydraulic pressure in the cylinder exceeds the predetermined value, the press contact is maintained and the screw rotation of the spindle is prevented. Automatic gap adjustment device.