JPH018747Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention Industrial Application Field The present invention relates to an adjusting device used to adjust the distance between the drum and brake shoe of a drum brake.

Prior Art Drum brakes installed on automobiles have a brake shoe lined with asbestos or the like placed inside a drum that rotates together with the wheels, and a wheel cylinder that operates this brake shoe using hydraulic pressure. By stretching it, it comes into pressure contact with the inner peripheral surface of the drum and stops rotating.

4 and 5 are schematic diagrams showing an example of the drum brake, in which A is a drum that rotates together with the wheels, B is a pair of brake shoes arranged inside drum A, and C is a brake shoe. U-B is a lining attached to the outer circumferential surface. D is a pair of wheel cylinders placed between a pair of brake shoes B;
Reference numeral E designates a return spring that is stretched between the pair of brake shoes B and pulls the pair of brake shoes B toward the inside of the drum A.

In the above configuration, the lining C attached to the brake shoe B is brought into pressure contact with the inner peripheral surface of the drum A,
When stopping the rotation of tram A, the brake shoe B is moved toward the outside of drum A by depressing the brake pedal (not shown), applying pressure to wheel cylinder D, and extending wheel cylinder D. Then, the lining C attached to the brake shoe B is brought into pressure contact with the inner peripheral surface of the drum A.
To unlock drum A, take your foot off the brake pedal and release the pressure on wheel cylinder D, and the elastic force of return spring E will cause brake shoe B to move inward of drum A. The lining C of the brake shoe B separates from the inner peripheral surface of the drum A.

In order to keep the braking performance of the drum brake of the above type constant, it is necessary to always keep the distance between the inner circumferential surface of the drum A and the lining C constant regardless of the wear of the lining C. For this reason, as shown in FIG. 6, an adjuster G having a gear F and screwing in the axial direction has been screwed into the end face of the wheel cylinder D as shown in FIG. The distance between the inner peripheral surface of the drum A and the lining C of the brake shoe B is regularly adjusted by extending or shortening the entire length of the wheel cylinder D interposed between the brake shoe B.

Problems to be solved by the invention The adjuster G screwed into the wheel cylinder D allows the inner peripheral surface of the drum A to be connected to the brake shoe B.
When adjusting the distance between the lining C and the sixth
As shown in the figure, an operator inserts a screwdriver-like tool A into the drum A through a hole A' formed in the drum A, engages the tip of the tool A with the gear F of the adjuster G, and screws the adjuster G. By doing so, the entire length of the wheel cylinder D is extended, and the lining C of the brake shoe B is once brought into contact with the inner peripheral surface of the drum A. Next, in this state, use the tool A to rotate the adjuster G in the opposite direction by several frames, and then rotate the wheel cylinder D.
By shortening the overall length of the drum A, the distance between the inner circumferential surface of the drum A and the lining C of the brake shoe B is kept constant.

However, in the above method, the worker manually rotates the adjuster G to once bring the lining C of the brake shoe B into contact with the inner circumferential surface of the drum A, resulting in variations in working time and at the same time The drawback was that the quality of the blade adjustment was inconsistent due to variations in contact pressure. Another disadvantage is that when a worker manually rotates the adjuster G using a screwdriver-like tool, it places a considerable strain on the worker's wrist.

(b) Means for solving the structural problems of the invention The drum brake adjustment device has a claw portion at the tip that engages with an adjuster screwed into the wheel cylinder of the drum brake, and sliding surfaces on opposite sides of the rear end. a claw member having a roller rotatably pivoted to one sliding surface; an air cylinder for rotatably sliding the claw member; and a claw member configured to contact both sliding surfaces of the claw member. a pair of guide plates placed on both sides of the claw member,
Of the pair of guide plates, the guide plate that contacts the slide surface on which the roller is not pivoted is configured with an elastic body for pressing the guide plate into pressure contact with the slide surface, and the claw member is reciprocated by an air cylinder. By moving it, the adjuster screwed into the cylinder of the drum brake is rotated.

Embodiment FIG. 1 is a drawing showing a drum brake adjustment device 1 according to the present invention, in which 2 is an air cylinder,
2a is a rod protruding from the tip of the air cylinder 2. Reference numeral 3 denotes a support stand attached to the tip of the air cylinder 2, and this support stand 3 has a base plate 4 fixed to the front end surface of the air cylinder 2, and a support base 3 attached to both sides of the base plate 4 at right angles to the base plate 4. A pair of fixed support plates 5a, 5b and a pair of support plates 5a, 5
It is constructed by a reinforcing member 6 bridged between both end surfaces of b. 7 is a bracket fixed to the tip of the rod 2a protruding from the air cylinder 2, and 8 is a claw member rotatably supported by the bracket 7 via a pin 9. A claw portion 8a is provided at the tip of this claw member 8 to engage with a gear F of an adjuster G screwed into the cylinder D of the drum brake described above, and a claw portion 8a that engages with a gear F of an adjuster G screwed into the cylinder D of the drum brake described above is provided on both opposing sides of the rear end. The first guide plate 11 and the second guide plate 12
and second slide surfaces 8b and 8c.
Further, a roller 10 for reducing frictional resistance is rotatably mounted on the first sliding surface 8b.
Reference numeral 11 denotes a first guide plate fixed to the support plate 5a of the support base 3, and is pivotally attached to the first slide surface 8b of the claw member 8 on the groove 11a formed on the surface of the first guide plate 11. The roller 10 is arranged to slide. Reference numeral 12 denotes a second guide plate that is elastically supported by the support plate 5b of the support base 3 via a plate spring 13, and the surface of the second guide plate 12 is It is in pressure contact with the second sliding surface 8c of the claw member 8.

In the above configuration, the adjuster G screwed into the wheel cylinder D of the drum brake is screwed by the drum brake adjusting device 1 according to the present invention,
When extending the full length of the wheel cylinder D and bringing the lining C of the brake shoe B into contact with the inner peripheral surface of the drum A, first insert the claw of the drum brake adjustment device 1 into the drum A through the hole A' provided in the drum A. The tip of the member 8 is inserted and the support base 3 of the drum brake adjustment device 1 is brought into contact with the surface of the drum A to position the drum brake adjustment device 1 on the drum A. Thereafter, the supply of air to the air cylinder 2 is started, and the air cylinder 2 is extended and shortened, thereby causing the claw member 8 to reciprocate in the left and right directions in the figure. In this state, air cylinder 2
extends and the claw member 8 moves to the right in the figure, the contact resistance between the first slide plate 11 and the first slide surface 8b is small, and the contact resistance between the second slide plate 12 and the second slide surface 8b is small.
Since the contact resistance between the sliding surfaces 8c is large, a counterclockwise rotational moment is generated in the claw member 8 as shown in FIG. 2, and the claw member 8 moves to the right in the figure while rotating counterclockwise. Therefore, the claw portion 8a of the claw member 8 does not engage with the gear F of the adjuster G.
Further, when the air cylinder 2 is shortened and the claw member 8 moves to the left in the drawing, a clockwise rotation moment is generated in the claw member 8 as shown in FIG. 3, contrary to the above, and the claw member 8 moves to the left in the figure while rotating clockwise. Therefore, the claw portion 8a of the claw member 8 is
The adjuster G will move while being engaged with the gear F of the adjuster G, and the adjuster G will rotate. By continuously repeating the above operation, the adjuster G spirals in the extension direction, and the lining C of the brake shoe B comes into contact with the inner peripheral surface of the drum A. When lining C comes into contact with the inner peripheral surface of drum A,
Since the adjuster G does not rotate any further, the movement of the claw member 8 to the left in the figure, in which the gear F of the adjuster G and the claw portion 8a are engaged, also stops. If the lining C of the brake shoe B comes into contact with the inner peripheral surface of the drum A in this way, the manual switching valve (not shown)
The air cylinder 2 is once extended by operating the , and the engagement between the claw portion 8a of the claw member 8 and the gear F of the adjuster G is released, and then the drum brake adjusting device 1 is removed from the drum brake. After that, as in the past, the operator inserts a screwdriver-like tool A into the drum A through the hole A' provided in the drum A of the drum brake, rotates the adjuster G by several frames in the opposite direction to the above, and then removes the cylinder. By shortening the overall length of D, a predetermined amount of gap is formed between the inner peripheral surface of drum A and lining C of brake shoe B.

C. Effect of the invention As mentioned above, in order to adjust the distance between the inner peripheral surface of the drum of a drum brake and the lining of the brake shoe, an adjuster screwed into a cylinder located inside the drum is rotated. When extending the total length of the cylinder and once bringing the lining into contact with the inner peripheral surface of the drum, if the screwing of the adjuster is done by an adjusting device operated by an air cylinder instead of manually, the working time will be constant and at the same time ,
The lining of the brake shoe can always be brought into contact with the inner peripheral surface of the drum with constant pressure.
Subsequent adjustment work can be performed in a stable condition, and the quality of drum brake adjustment can be maintained at a constant level. In addition, the manual work required to adjust the drum brakes involves simply returning the adjuster screwed into the cylinder a few steps, which eliminates strain on the operator's wrists.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a drum brake adjusting device according to the present invention, and FIGS. 2 and 3 are partial sectional views showing its use. Figures 4 and 5 are
FIG. 4 is a front view, and FIG. 5 is a sectional view taken along the line taken along the line shown in FIG. 4. FIG. 6 is a schematic diagram showing a state in which the adjuster is rotated with a driver-like tool. DESCRIPTION OF SYMBOLS 1... Drum brake adjustment device, 2... Air cylinder, 8... Claw member, 8a... Claw portion, 8b...
...First sliding surface, 8c... Second sliding surface, 10... Roller, 11... First guide plate,
12... Second guide plate, 13... Leaf spring.

Claims (1)

[Scope of utility model registration request] It has a claw part at the tip that engages with the adjuster screwed into the wheel cylinder of the drum brake, has sliding surfaces on both opposing sides of the rear end, and has a roller rotatably pivoted on one sliding surface. a claw member, an air cylinder for sliding the claw member in a rotatable state, a pair of guide plates disposed on both sides of the claw member so as to be in contact with both sliding surfaces of the claw member, and the pair of guide plates. Of the guide plates,
A drum brake adjusting device comprising: a slide surface on which the roller is not pivotally mounted; and an elastic body for pressing a guide plate in contact with the slide surface.