JP2000136838A - Disk brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjusting mechanism and an over-adjusting preventive mechanism by forming a subassembly with an adjusting screw, spring receiver, cam mechanism, etc., together with a brake piston and an adjusting sleeve, to be assembled in a brake cylinder by inserting the subassembly as it is, in a disk brake device. SOLUTION: In this disk brake device, an over-adjusting preventing stepped plunger 5b is provided in a brake piston 5, a plug 5e having a clutch surface with an adjusting sleeve 5k is fitted not rotatable and slidable to the brake piston 5, and the plug 5e is energized by a limiter spring 5f assembled in the brake piston 5, so as to move the plug 5e by the plunger 5b to an over adjusting preventing position against the limiter spring 5f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake device having a parking auto-adjustment mechanism incorporated in a disc brake piston and a cam mechanism for transmitting a parking operation force. It is possible to remarkably improve the assemblability with the mechanism and the parking operation cam mechanism.

[0002]

2. Description of the Related Art A cam mechanism for transmitting the parking operation force in the above-mentioned disc brake device includes a ball cam and a tappet, and various concrete mechanisms are available. The over-adjustment preventing operation is performed by pulling the adjusting screw against the urging spring by the brake oil pressure. As a typical example of such a conventional example, Japanese Patent Publication No. Sho 5
There is one described in JP-A-7-61937. This has the structure shown in FIG. The outline of the above conventional example is as follows. A piston 54 of an adjustment sleeve 53 is fitted to the brake piston 52, and an adjustment screw 55 is screwed to the adjustment sleeve 53. The adjusting screw 55 is connected to the rotation regulating plate 5.
The rotation is restricted by 6, but it is movable in the axial direction. A spring receiver 57 is fixed to the wall surface of the caliper by a circlip 58 together with the rotation regulating plate 56.
The adjusting screw 55 is urged rightward by a spring 59 whose one end is supported by a spring receiver 57, and the tappet 62 is sandwiched between the free piston 60 and the cam 61 by this urging force. Adjust sleeve 5
The third flange 53a is pressed against the conical surface of the brake piston 52 by a corrugated spring 63 to restrict its rotation. However, as the wear of the brake pad progresses, the screw of the adjusting screw 55 and the adjusting sleeve 53 is screwed. When the brake piston 52 moves forward more than the backlash, the adjusting screw prevents further movement of the adjusting sleeve from following the brake piston 52, so that the flange 53 a of the adjusting sleeve 53 is moved from the conical surface of the brake piston 52. It becomes rotatable at a distance. When the rotation becomes possible, the adjusting sleeve 53 is pushed by the corrugated spring 63 and moves forward while rotating, and the flange 53 a
Hit the conical surface. This is the adjustment effect on the wear progress of the brake pad. On the other hand, if excessive brake oil pressure is applied and the brake piston advances abnormally,
Since the excessive brake oil pressure acts on the piston 54 of the adjustment sleeve, the adjustment sleeve 53 follows the brake piston and can rotate without the flange 53a of the adjustment sleeve 53 being separated from the conical surface of the brake piston 52. No excessive adjustment action is performed. At this time, the adjusting screw 55 is pulled to the left by the adjusting sleeve 53 against the spring 59. This is the overadjustment preventing action. When the camshaft 61 is rotated by the brake operation using the parking lever, the tappet 62 is rotated.
As a result, the free piston 60 is pushed by the cam action, and the brake piston 52 is pushed out via the adjusting screw 55 and the adjusting sleeve 53, and the brake is operated. In the above-described conventional device, the spring receiver 57, the spring 59, and the adjusting screw 55 are incorporated in a cylinder, fixed with the circlip 58, and the brake piston 52, the adjusting sleeve, and the corrugated spring 63 are fixed. These must be assembled in a pre-assembled state. In this assembling operation, since the adjusting sleeve must be screwed into the adjusting screw, this assembling operation requires skill and is extremely troublesome. Even when the cam mechanism is a ball cam, the above-mentioned problem exists because the relationship between the brake piston, the adjust sleeve, the adjust screw, the return spring for the adjust screw, and the rotation regulating mechanism for the adjust screw is almost the same as that described above. Has not changed. In the prior art, the adjusting screw is urged by a return spring (the spring 59), and the adjusting screw is moved against the urging force to prevent overadjustment. There is a greatest reason for the above problem.

[0003]

Therefore, in order to solve the above-mentioned problems, an adjusting screw, a spring receiver, a cam mechanism, etc., together with a brake piston and an adjusting sleeve, are made into a sub-assembly, which is directly inserted into a brake cylinder and assembled. It is an object of the present invention to devise an adjusting mechanism and an over-adjustment preventing mechanism.

[0004]

Means taken for solving the above-mentioned problem are the first one attached to the brake piston 5.
An adjusting mechanism including a first screw 5k that is pressed by the spring 5i to follow the brake piston, a second screw 6b that reversibly fits with the first screw, an overadjustment prevention mechanism, and an adjusting screw Assuming a disc brake device provided with a cam mechanism for pushing out, the following (a) is configured. (A) The brake piston 5 is provided with a step plunger 5b for preventing overadjustment, and the plug 5e having the second clutch surface engageable with the first clutch surface of the first screw 5k cannot be rotated and cannot be rotated. The plug 5e is fitted to the brake piston 5 so as to be slidable in the axial direction of the rotor, the plug 5e is urged by a second spring 5f incorporated in the brake piston, and the plug 5e is pushed by the plunger 5b. Movement to the over-adjustment prevention position against

[0005]

The plug 5e moves together with the brake piston, and the first screw 5k follows the plug 5e. However, as the wear of the brake pad advances, the stroke of the brake piston is reduced by the second screw 6b and the first screw 5k. When the backlash of the screw portion between them becomes equal to or more than the backlash, the first screw 5k is prevented from moving by the second screw 6b, so that the clutch surface of the plug 5e is separated from the clutch surface of the first screw 5k. Thus, an adjusting action (braking gap adjusting action) is performed. This is the adjusting action, but there is no difference from the adjusting action of the conventional one. The brake oil pressure in the cylinder acts on both the left and right sides of the stepped plunger 5b for preventing overadjustment. However, since the pressure receiving area on the end face in the brake operating direction is larger than the pressure receiving area on the brake cylinder side end face, the brake oil pressure is overadjusted. The preventing stepped plunger 5b acts in a direction of retracting while pushing back the plug 5e against the second spring 5f. Under normal brake operating oil pressure, the second spring is superior, and the overadjustment-preventing stepped plunger does not move from the neutral position (the position shown in the drawing), so that there is no hindrance to the adjustment operation as described above. When the excessive brake oil pressure acts, the caliper deforms abnormally, and the brake piston 5 advances excessively. At this time, the over-adjustment preventing stepped plunger 5b responds to the excess oil pressure. The spring retreats relatively to the brake piston against the second spring 5f, so that the clutch surface is prevented from separating from the clutch surface of the first screw, which is prevented from moving forward by the second screw,
Continue to prevent the first screw from becoming rotatable. As a result, an over-adjustment preventing action is performed. As described above, the overadjustment preventing action is performed by the overadjustment preventing stepped plunger 5b incorporated in the piston and the second spring 5f.
There is no need to interpose a return spring for preventing overadjustment (for example, the “spring 59” in the related art described above) between the spring receiver fixed to the inner surface of the cylinder and the second screw (adjust screw). Therefore, the brake piston, the adjustment mechanism, the overadjustment prevention mechanism, and the cam mechanism for parking operation can be assembled outside the cylinder. Therefore, the sub-assembly can be assembled by simply inserting the sub-assembly into the brake cylinder as it is, and these assembling operations are performed very simply and quickly without requiring special skills.

[0006]

[Embodiment 1] In the disc brake device according to the above-mentioned solution, a second screw 6b is attached to a cup-shaped spring receiver 6g.
And a driven cam disk 6j integral with the camshaft 6c is mounted on the spring receiver, and a thrust is provided at the open end of the spring receiver. The plate (plate) 6e is fixed, and the compression spring 6 is placed between the bottom surface of the spring receiver 6g and the driven cam disk 6i.
a thrust plate 6e is provided on the thrust plate 6e so as to engage with the cylinder bottom surface of the caliper with the interposition a.

[0007]

The compression spring 6a functions as a return spring (corresponding to the "spring 59" in the prior art described above) of the driven cam disk 6i to the parking brake operation. 6g, driven and driven cam discs 6i, 6j, and thrust plate 6e, these are inserted into the cylinder while keeping them in the sub-assembly, and the rotation stop 6f is engaged with the cylinder bottom face to make the piston, Adjustment mechanism,
This cam mechanism is easily and easily assembled to the cylinder together with the over-adjustment mechanism and the like.

[0008]

[Second Embodiment] A cylindrical seal 11 having a hard seal cover 10 fitted on the outer surface is fitted to the outer end of the cam shaft 6c of the disc brake device according to the first embodiment.

[0009]

The shaft end of the camshaft 6c is sealed by the cylindrical seal 11 reinforced by the hard seal cover 10, and
Thereby, the movement of the lever 8 fixed to the shaft end can be restricted, and furthermore, the torsion type lever spring 9 can be guided and held by the seal cover 10, so that the mechanism and structure of the shaft end portion are achieved. Can be simplified.

[0010]

Next, an embodiment will be described with reference to FIGS. A small-diameter cylinder is provided at the bottom of the brake piston 5 fitted to the cylinder of the caliper 1, and a stepped plunger 5b for preventing over-adjustment is fitted to this cylinder. The small diameter portion is sealed by a cup seal 5d and a backup ring 5c. A plug 5e is fitted to the brake piston 5, and the plug 5e is not rotatable with respect to the brake piston 5, but is slidable in the rotor axial direction, and is braked by a limiter spring (second spring) 5f. It is pressed against the bottom surface of the piston 5. An adjusting sleeve (first screw) 5k is screwed to the adjusting screw (second screw) 6b with a predetermined backlash, and the screwing is reversible fitting. The reversible fitting is a screw in which the two screw elements cause relative rotation when a relative axial force acts between the two screw elements. Reversible fitting can be achieved by appropriately setting the angle and the coefficient of friction. The adjusting sleeve (first screw) 5k is pushed by an adjusting spring (first spring) 5i,
The conical clutch surface of the flange is pressed against the conical clutch surface of the plug 5e. The adjustment spring (first spring) 5i is a compression spring interposed between an adjustment plate 5h and a clip (snap ring) 5j fitted in an annular groove on the inner surface of the end of the brake piston 5. And the above adjustment plate 5
h and the flange of the adjusting sleeve (first screw) 5k via the thrust bearing 5g.
Since the limiter spring (second spring) 5f is interposed between the adjust plate 5h and the plug 5e, the spring force of these springs is limited to the flange of the adjust sleeve 5k, the plug 5e, the brake piston 5e. , Clip 5j. Accordingly, the brake piston 5, the stepped plunger 5b, the plug 5e, the adjusting sleeve (first screw) 5k, the adjusting screw (second screw) 6b, the limiter spring (second spring) 5f, and the adjusting spring (first spring) spring)
The sub-assembly 5i and the clip 5j are independent (non-separated) outside the cylinder of the caliper 1. The driven cam disk 6i of the adjusting screw (second screw) 6b and the driving cam disk 6j of the cam shaft (cam shaft) 6c are accommodated in a cup-shaped cam case (also serving as a spring receiver) 6g, and the bottom of the cam case 6g is housed. A cam spring (compression spring) 6a is interposed between the drive cam disk 6i and the driven cam disk 6i. On the other hand, a driving cam disk 6j is connected via a thrust bearing 6d by a thrust plate (plate) 6e fixed to the right end of the cam case 6g. A cam bearing (wedge ball) 6h is sandwiched between the cam discs 6i and 6j. Since the spring force of the cam spring 6a is confined in the cam case 6g, the cam case 6g, the cam spring 6a, the driven cam disk 6i of the adjusting screw 6b, the cam shaft 6
The beating cam disk 6j and the cam bearing 6h of FIG. 3C are independent sub-assemblies outside the cylinder of the caliper 1 (see FIG. 2). A lock pin (rotation stop) 6f protrudes from the outer surface of the thrust plate 6e. The lock pin 6f is fitted into a pin hole on the bottom of the cylinder to stop the rotation of the thrust plate. Then, the adjusting screw (second screw) 6b is first incorporated in the latter assembly,
Then, the adjustment sleeve of the former assembly (first
Screw) 5k and straddles the above-mentioned two assemblies, so that the above-mentioned two assemblies are
Through the sub-assembly. This sub-assembly, in which the former assembly and the latter assembly are integrated, is inserted into a cylinder of a caliper, a lock pin 6f is fitted into a pin hole on the bottom surface of the cylinder, and a cam shaft (cam shaft) 6c is connected to the caliper. After projecting from the bearing, a dust seal 11 is attached, and a parking brake operating lever 8 is attached to the shaft end with a washer 1.
2. Secure with nut 13. This completes the attachment to the caliper. In the normal brake operation state, the adjusting sleeve (first screw) 5k follows the brake piston and the plug 5e, and is within a range equivalent to the backlash of the screwing portion with the adjusting screw 6b.
Although it moves in the rotor axis direction with respect to the adjusting screw (second screw) 6b, when the wear of the brake pad advances and the stroke of the brake piston exceeds the above-mentioned backlash range, the adjusting sleeve (first screw) is used. ) 5k is regulated by the adjusting screw (second screw) 6b and cannot follow the plug any more. Here, the clutch surface of the flange separates from the clutch surface of the plug, and the adjusting (automatic adjustment of brake clearance) is performed. ) Is made. Even when the adjustment sleeve (first screw) 5k reaches the stage where the adjustment screw (second screw) 6b is prevented from following the plug 5e, the caliper is still deformed due to an abnormally high brake hydraulic pressure. When the brake piston is pushed out, the brake oil pressure is applied to both end surfaces of the stepped plunger 5b. Therefore, the force due to the difference in the pressure receiving area of both end surfaces is applied to the limiter spring (second second end) against the plug 5e. Spring) exceeds the set load of 5f, and plug 5
e is pushed out against the limiter spring (second spring) 5f. As a result, the plug 5e does not separate from the clutch surface of the flange of the adjusting sleeve (first screw) 5k, and therefore, over-adjustment is prevented. When the camshaft 6c is rotated by the lever 8, the adjusting screw (second screw) 6b is pushed out by the cam mechanism by the two cam disks 6i, 6j and the cam bearing 6h, and the adjusting sleeve (first screw). 5k, the brake piston 5 is pushed out through the plug 5e to operate the brake. A cylindrical dust seal 11 is fitted to the outer end of the camshaft 6c and the bearing of the caliper to seal the shaft end of the camshaft 6c. This dust seal 11 is a multi-stage lip seal ring, and a stainless steel seal cover 10 is fitted on the cylindrical outer surface thereof. Since the axial force of the dust seal 11 is reinforced by the seal cover 10 made of stainless steel, the movement of the lever 8 fixed to the shaft end by the dust seal 11 can be restricted. Also,
Since the stainless steel seal cover 10 is rigid and has high wear resistance, it can guide and support the coil portion of the lever spring 9 (torsion spring). Reference numeral 2 denotes a boot, 3 denotes a boot ring, 4 denotes a piston seal, 6 denotes a cam assembly, and 7 denotes a seal.

[0011]

[Effect] As described above, the adjusting mechanism including the plug, the adjusting sleeve (first screw), the adjusting screw (second screw), the adjusting spring (first spring), the plug, and the over An overadjustment prevention mechanism including an adjust prevention stepped plunger, a limiter spring (second spring) for defining a start condition of an overadjustment prevention operation by the plunger, an adjustment screw (second screw), a cam portion, A cam mechanism constituted by a cam spring or the like can be assembled into a sub-assembly independently and integrally outside the cylinder. By simply inserting this into the caliper cylinder, all of the above mechanisms can be assembled to the caliper, so that the work of assembling the disc brake device is simple, simple, and easy. Further, by fitting and fixing a cylindrical seal in which a hard seal cover is fitted to the outer surface of the outer end of the camshaft, this is also used as a movement preventing member for the lever fixed to the shaft end, and further to this Since the lever spring can be fitted and supported, the mechanism and structure of the shaft end can be made extremely simple and simple.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is an assembled external view of a cam mechanism in the embodiment of FIG.

FIG. 3 is an exploded perspective view of the cam mechanism shown in FIG.

FIG. 4 is an external view of the embodiment of FIG.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Caliper 2 ... Boot 3 ... Boot ring 4 ... Piston seal 5 ... Brake piston 5a ... Seal 5b ... Stepped plunger 5c ... Backup 5d ... Cup Seal 5e Plug 5f Limiter spring (second spring) 5g Thrust bearing 5h Adjust plate 5i Adjust spring (first spring) 5j Clip (snap ring) 5k Adjust sleeve (first screw) 6 Cam assembly 6a Cam spring 6b Adjust screw (second screw) 6c Cam shaft (cam shaft) 6d・ Thrust bearing 6e ・ ・ ・ Thrust plate (plate) 6f ・ ・ ・ Lock pin 6g ・ ・ ・ Cam 6h ... cam bearing (wedge ball) 6i ... driven cam disk 6j ... drive cam disk 7 ... seal 8 ... lever 9 ... lever spring (torsion) Spring) 10 ... Seal cover 11 ... Dust seal 12 ... Washer 13 ... Nut 51 ... Cylinder 52 ... Brake piston 53 ... Adjust sleeve 53a ... Adjust sleeve flange 54 ..Piston 55 ・ ・ ・ Adjust screw 56 ・ ・ ・ Rotation control plate 57 ・ ・ ・ Spring receiver 58 ・ ・ ・ Circlip 59 ・ ・ ・ Spring 60 ・ ・ ・ Free piston 61 ・ ・ ・ Cam 62 ・ ・ ・ Tappet 63 ... Corrugated springs

Claims (6)

[Claims] A first piston attached to a brake piston;
An adjusting mechanism (braking gap adjusting mechanism) having a first screw 5k that is pressed by the spring 5i to follow the brake piston 5, a second screw 6b that reversibly fits with the first screw, and the like; In a disc brake device provided with an adjustment prevention mechanism and a cam mechanism for pushing out the second screw 6b, a brake piston 5 is provided with a stepped plunger 5b for preventing overadjustment, and the first screw 5k of the first screw 5k has
A plug 5e having a second clutch surface capable of engaging with the clutch surface of the first embodiment is fitted to the brake piston 5 so as to be non-rotatable and slidable in the axial direction of the rotor, and the plug 5e is incorporated in the brake piston. A disc brake device which is biased by a second spring 5f and moves the plug 5e to an over-adjustment preventing position against the second spring 5f by the plunger 5b. 2. A driven cam disk 6i integral with the second screw 6b is mounted in a cup-shaped spring receiver 6g so as to be non-rotatable and slidable in the rotor axial direction. A cam shaft 6c is mounted on the spring receiver 6g. An integrated drive cam disk 6j is provided, a thrust plate 6e is fixed to the open end of the spring receiver 6g, and a compression spring 6a is interposed between the bottom surface of the spring receiver 6g and the driven cam disk 6i. 2. The disc brake device according to claim 1, wherein a rotation stopper 6f engaging with the bottom surface of the first cylinder is provided on the thrust plate 6e. 3. The disc brake device according to claim 1, wherein a cylindrical seal 11 having a hard seal cover 10 fitted on an outer surface thereof is fitted to an outer end portion of the cam shaft 6c. 4. A first motor mounted on a brake piston (5).
A braking screw adjusting mechanism having a first screw 5k pressed by the spring 5i to follow the brake piston 5, and a second screw 6b reversibly fitted with the first screw;
A disk brake device provided with an extruding mechanism capable of mechanically braking by extruding the screw 6b in a direction approaching the rotor, wherein the first screw 5k has a first clutch surface, and the first screw 5k has a first clutch surface. A plug 5e having an engageable second clutch surface is fitted to the brake piston 5 so as to be non-rotatable and slidable in the rotor axial direction.
At least one of the two is biased by a second spring 5f in a direction in which the clutch surface is separated, and has a plurality of seal engagement portions fitted to the brake piston 5 so as to be slidable in the rotor axial direction. A stepped plunger 5b having a larger cross-sectional area on the side closer to the rotor among the plurality of seal engagement portions, and when the brake fluid pressure exceeds a predetermined value, the first screw is engaged by engagement of the clutch surface. A disc brake device wherein the plunger 5b moves in a direction away from the rotor by bending the second spring 5f so as to prevent rotation of 5k. 5. The pushing mechanism according to claim 1, wherein said pushing mechanism is provided with said second screw 6b.
A driven cam disk 6i at the end, a cup-shaped spring receiver 6g that accommodates the driven cam disk 6i so as to be non-rotatable and slidable in the rotor axial direction, and a plate 6e fixed to the other end of the spring receiver 6g. The driven cam disk 6i and the plate 6
5. The disc brake device according to claim 4, further comprising a ball and a drive cam disc 6j between the disc brake device and the drive cam disc. 6. The disc brake device according to claim 5, wherein said pushing mechanism is sub-assembled.