JPH08219204A - Negative type disc brake device - Google Patents

Abstract

PURPOSE: To provide a negative type disc brake device in which the reliability of its adjusting mechanism is high and workability of parts is easy. CONSTITUTION: Adjusting bolts 23 having adjusting teeth 23c along the outer circumferences of the head parts 23b of bolts 23a which are inclined at an approximately intermediate angle in the shaft and surface directions of the rotor 1 of a negative type disc brake device, are threadedly engaged with the loose end parts of levers 3, 4, respectively. Push rods 21 whose one end is brought in contact with the tip end of the adjusting bolts 23, and other end is opposed to the acting surfaces 16a, 16b of a cam 16, are fitted in the loose end parts of the levers 3, 4 so as to be movable in the shaft direction of the rotor 1. A plate-like adjusting lever 24 having a pair of adjusting claws 24a which are engaged with the adjusting teeth 23c of the adjusting bolts 23 at approximately right angles, is integrally rotatively fixed with the cam 16 so as to compose the negative type disc brake device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative type disc brake device having an adjusting mechanism for compensating for wear of a friction material of a disc brake.

[0002]

2. Description of the Related Art One of the conventional techniques of this type is
There is one disclosed in Japanese Patent No. 31230.

[0003]

[Problems to be Solved by the Invention]
The No. 1230 device has the following problems. (1) Since there is no means for always restraining the rotation of the adjustment bolts 1 and 2, there is a possibility that the adjustment bolts 1 and 2 may blindly move or fall out due to vibration or the like.

(2) When the cam 86 is rotated counterclockwise in FIG. 1, the contact portion 36 of the adjusting lever 3 causes the vertical surface 221 of the ratchet portion 22 of the adjusting bolt 2 to move.
Press to rotate the adjusting bolt 2 in the direction away from the cam 86 for automatic adjustment. However, when the contact portion 36 and the ratchet portion 22 come into contact with each other due to the wear of the pad, even if the cam 86 rotates clockwise, the contact portion 36 pushes the top of the taper 222 of the ratchet portion 22, and the adjust bolt 2 is pushed. It is rotated in the direction of approaching the cam 86. As described above, when the adjusting lever 3 rotates clockwise, the contact portion 36 may slide along the taper 222 without rotating the adjusting bolt 2, but the contact portion 36 has a structure to escape. Absent. That is, in this conventional device, since the adjusting bolt 2 approaches and separates from the cam 86 by the rotation of the cam (adjusting lever) in both directions, the automatic adjustment corresponding to the wear of the pad is not correctly performed or the adjustment is unstable. May be.

(3) Disc-shaped head 2 of the adjusting bolt 2
Since the ratchet portion 22 is formed on the back surface of the No. 1, it is difficult to process the adjust bolt 2. Also, the adjust lever 3 is also abutting part 3 in a direction perpendicular to the Z-shaped tip.
Since the shape is such that 5 and 36 are extended, there is a problem that formation is not easy.

[0006]

In order to solve the above problems, in the present invention, a pair of levers provided on both sides of a rotor and having a friction material fixed thereto, and one end portions of the both levers are rotatable. A coupled pivot, an actuating spring that acts to reduce the opening of both levers to pinch the rotor, and a cam that is arranged at the other end of both levers to expand the opening and release the brake. In a negative type disc brake device comprising a cam and a pair of adjusting mechanisms which are respectively interposed between the levers and correct the displacement amount of the lever due to wear of friction material to compensate for a constant expansion of the lever due to rotation of the cam. The adjusting mechanism has adjusting bolts, each of which has adjusting teeth on the outer circumference of a bolt head inclined at a substantially intermediate angle between the rotor axial direction and the surface direction, and is screwed to the other end of the lever, and one end of which is the adjusting bolt. of A push rod, which is in contact with the end and the other end of which faces the working surface of the cam, is fitted into the other end of the lever so as to be movable in the rotor axial direction, and engages with the adjusting teeth of the adjusting bolt at a substantially right angle. A plate-shaped adjusting lever having a pair of adjusting claws is integrally fixed to the cam to form a negative type disc brake device.

[0007]

Since the device of the present invention is constructed as described above, the following effects can be obtained. (1) Since the adjusting claw of the adjusting lever is always in contact with the adjusting teeth of the adjusting bolt, the adjusting bolt does not loosen due to vibration or the like. (2) Since the adjusting claws at the tip of the flat plate-shaped adjusting lever engage with the adjusting teeth formed on the outer periphery of the head of the adjusting bolt at a substantially right angle, the automatic adjustment is surely and stably performed. (3) Since the adjusting teeth are formed on the outer circumference of the adjusting bolt head,
This head can be processed by punching with a press or the like. Also, since the adjusting lever is also flat, both can be easily processed. (4) In the unlikely event that the adjusting lever is broken, the automatic adjustment will not work, but if the adjusting teeth of the adjusting bolt are rotated with a tool such as a screwdriver, manual adjustment can be easily performed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, 1 is a rotor of a disc brake, 2 is a bracket for supporting a brake device, 2a is a mounting seat portion for mounting the bracket 2 on a vehicle body (not shown), 2b is a mounting hole, and 2c is a bracket 2. A lever mounting arm portion provided at one end and a cam mounting arm portion 2d provided at the other end of the bracket 2.

Reference numerals 3 and 4 are a pair of levers formed substantially symmetrically so as to sandwich the rotor 1, and one end portions 3a and 4a thereof are provided.
And the overlapping portion is inserted into the lever mounting arm portion 2c of the bracket 2, and the levers 3 and 4 are pivotally supported on the bracket 2 by a lever shaft pin (pivot shaft) 5 penetrating these members. 6 (see FIGS. 2 and 3) is a washer, and 7 is a retaining ring.

Reference numeral 8 is a friction pad applied to the inside of each of the levers 3 and 4, 8a is a friction material thereof, and 8b is a back plate. Reference numeral 9 is a bolt for fixing each friction pad 8 to the levers 3, 4, and 10 is a spring washer. Reference numeral 11 denotes a bolt-shaped rod that penetrates the free ends of the levers 3 and 4, and a coil-shaped actuating spring 12 is wound around the protruding end of the rod 11 and is contracted by a nut 13. Reference numeral 14 denotes spring seats arranged at both ends of the actuating spring 12, and 15 denotes a washer inserted between the spring seat 14 and the nut 13.

Reference numeral 16 is a cam, and the cam 16 has its shaft 17 (see FIG. 4) attached to the cam mounting arm portion 2 of the bracket 2.
It is rotatably fixed to the bracket 2 by passing through d. Reference numeral 18 is an operating lever fixed to the shaft 17, 19 is a spring washer, and 20 is a nut.

In this embodiment, holes 3b and 4b facing the cam 16 are provided at the free ends of the levers 3 and 4 in parallel with the axis of the rotor 1, and the push rods 21 are slid into the holes 3b and 4b, respectively. Insert freely. The push rod 21 has a spherical end 21a facing the cam 16, the other end is formed on a sloped surface 21b of about 45 °, and an O-ring 22 is formed in an annular groove provided in the middle of the body. Is attached to prevent the push rod 21 from falling off due to vibration or the like and from freely rotating.

Further, at the free ends of the levers 3 and 4, screw holes 3c and 4c are provided at an angle of intersection of approximately 45 ° with the holes 3b and 4b, and the head of a bolt 23a screwed with the screw holes 3c and 4c is provided. Saw-toothed adjusting teeth 23c around the formed disk 23b
The adjusting bolt 23 formed with is screwed into the screw holes 3c and 4c.

Further, an intermediate portion of an adjusting lever 24 having arms protruding to both sides is fixed to the shaft 17 of the cam 16 so that the cam 16 is
So that it rotates together with. The adjustment lever 24 may be fixed to the shaft 17 by caulking, welding, bolting, or the like, but in the present embodiment, the grease nipple 26 is screwed into the shaft 17 via the flat washer 25. The grease nipple 26 is for supplying grease to the fitting holes of the cam 16 and the shaft 17 formed in the cam mounting arm portion 2d and the working surfaces 16a and 16b of the cam 16.

Further, a pair of adjusting claws 24a that engage with the adjusting teeth 23c of the adjusting bolt 23 at substantially right angles are formed at both ends of the adjusting lever 24. The engagement state between the adjusting claw 24a and the adjusting tooth 23c is preferably slightly inclined so that the tip of the adjusting claw 24a is farther from the center of the adjusting bolt 23. This is because the levers 3 and 4 move in a direction to reduce the opening degree thereof as the friction material 8a wears, and the adjusting bolt 23 follows the screwing out of the levers 3 and 4 by the adjusting action. This is for coping with a change in the engagement position between the adjusting claw 24a and the adjusting tooth 23c.

Next, the operation of the device of the present invention constructed as described above will be described. The negative type disc brake device
The opening of both levers 3 and 4 is reduced by the urging force of the normal operation spring 12, and the rotor 1 is clamped to operate the brake.
At this time, the adjusting mechanism is in the state shown in FIGS. 1 and 4, and at this time, a predetermined gap is secured between the working surfaces 16a, 16b of the cam 16 and the end portion 21a of the push rod 21. Step on the brake pedal (not shown) Cam 1
When 6 is rotated, the action surfaces 16a and 16b of the cam 16 come into contact with the end portion 21a of the push rod 21, the opening degrees of both levers 3 and 4 are expanded, and the brake is released.

When the friction material 8a of the friction pad 8 is worn,
Both levers 3 and 4 move in a direction to reduce their opening.
Then, the engaging position of the adjusting tooth 23c and the adjusting claw 24a is as shown in FIG.
In, the center of the adjusting tooth 23c changes so as to approach the adjusting claw 24a. By utilizing the change in the engagement position due to this wear, that is, when the friction material 8a wears, the relative movement amount of the adjusting tooth 23c and the adjusting pawl 24a becomes larger than that in the normal state, and therefore the adjusting tooth 23c is rotated by the adjusting pawl 24a. Adjusting bolt 23
Is screwed out from the levers 3 and 4. On the other hand, the push rod 21 sinks into the holes 3b and 4b, and the push rod 2
A gap between the end 21a of No. 1 and the working surfaces 16a and 16b of the cam 16 is secured to a predetermined value.

[0018]

Since the device of the present invention is constructed as described above, the following operational effects can be obtained. (1) Since the adjusting claw 24a of the adjusting lever 24 is always in abutting engagement with the adjusting tooth 23c of the adjusting bolt 23, the adjusting bolt 23 is not loosened due to vibration or the like. (2) Since the adjusting claw 24a at the tip of the flat plate-shaped adjusting lever 24a engages with the adjusting tooth 23c formed on the outer periphery of the head 23b of the adjusting bolt 23 at a substantially right angle, the automatic adjustment is surely and stably performed. Be done. (3) Since the adjusting teeth 23c are formed on the outer periphery of the head 23b of the adjusting bolt 23, the head 23b can be processed by punching with a press or the like. Further, since the adjusting lever 24 is also flat, both can be easily processed. (4) If the adjustment lever 24 is broken, the automatic adjustment will not work, but the adjustment teeth 23c of the adjustment bolt 23 will be lost.
You can easily make manual adjustments by rotating the tool with a tool such as a screwdriver.

[Brief description of drawings]

FIG. 1 is a front view of the device of the present invention.

FIG. 2 is a plan view of the device of the present invention.

FIG. 3 is a right side view of FIG.

FIG. 4 is a left side view of FIG.

5 is a view of the main part of FIG. 1 as viewed in the direction of arrow A. FIG.

[Explanation of symbols]

 1 Rotor 2 Bracket 2a Mounting Seat 2b Mounting Hole 2c Lever Mounting Arm 2d Cam Mounting Arm 3 Lever 3a One End 3b Hole 3c Screw Hole 4 Lever 4a One End 4b Hole 4c Screw Hole 5 Lever Shaft Pin (Pivot) 6 Washer 7 retaining ring 8 friction pad 8a friction material 8b back plate 9 bolt 10 spring washer 11 rod 12 actuating spring 13 nut 14 spring washer 15 washer 16 cam 16a, 16b working surface 17 shaft 18 actuating lever 19 spring washer 20 nut 21 push rod 21a End 21b Slope 22 O-ring 23 Adjustment bolt 23a Bolt 23b Head (disk) 23c Adjustment tooth 24 Adjustment lever 24a Adjustment claw 25 Flat washer 26 Grease nipple

Claims (1)

[Claims] 1. A pair of levers disposed on both sides of a rotor and having friction members fixed thereto, a pivot shaft to which one end portions of the both levers are rotatably coupled, and the opening degree of the both levers being reduced to sandwich the rotor. An operating spring that acts to press, a cam that is arranged at the other end of both levers and that releases the brake by expanding its opening, and a lever that is interposed between this cam and both levers and that wears the friction material. In a negative type disc brake device comprising a pair of adjusting mechanisms for compensating the constant lever expansion due to the rotation of the cam, the adjusting mechanism has a substantially intermediate angle between the rotor axial direction and the surface direction. Adjustment bolts having adjustment teeth on the outer circumference of the tilted bolt head are respectively screwed to the other ends of the levers, one end abuts the tip of the adjustment bolt, and the other end faces the working surface of the cam. Push lock Is fitted to the other end of the lever so as to be movable in the axial direction of the rotor, and a plate-shaped adjusting lever having a pair of adjusting claws that engage with the adjusting teeth of the adjusting bolt at a substantially right angle is integrally fixed to the cam. A negative type disc brake device characterized by the above.