JPS5814252Y2 - brake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake shoe clearance adjustment device for adjusting the clearance between a brake shoe and a drum of a drum brake of an automobile.

An adjuster rotatably supported by a body fixed to a backing plate of an automobile drum brake and having a gear part, and a non-rotatable adjuster bolt concentrically screwed into the adjuster and engaged with a brake shoe. , the adjuster is attached to the body at one end separated from the gear part in the direction of the rotational axis of the adjuster, and the engaging part at the other end is engaged between the teeth of the gear part by its own elastic force, so that the adjuster A brake shoe clearance adjustment device equipped with a lock spring lever that restricts blind rotation of the brake shoe clearance is known, but in the past.

As shown in FIG. 5, one end of the lock spring lever 22 is firmly clamped together with a washer 23 between the body 21 and the head of a bolt 240 screwed into the body 21.
K was fixed.

In the specific conventional device, when the adjuster 20 is slowly rotated in the direction of the arrow in FIG. As the lock spring lever 22 rotates, it moves only in the vertical direction as shown by ■ to ■ in Fig. 6, and the engaging part of the lock spring lever 22 quietly contacts the tooth next to the tooth 20a, so this contact generates a rattling sound. There was nothing to do.

Therefore, when the brake is assembled to the vehicle or after driving, the clearance between the brake shoe and the drum can be adjusted by rotating the teeth of the adjuster with a screwdriver or other tool until the brake shoe contacts the drum. In the general adjustment method, which is done by rotating the textbook in the opposite direction,
The adjustment work involves inserting a tool such as a screwdriver into a small hole in the backing plate or drum and turning the adjuster teeth, so it cannot be seen directly with the naked eye, so with conventional equipment, it is difficult to check the number of teeth when returning. The clearance between the brake shoes and the drum could not be adjusted properly.

2. In the brake shoe clearance adjustment device as described above, if the retaining part of the lock spring lever passes over one tooth of the gear part of the adjuster when the adjuster is rotated, the engaging part of the lock spring lever will be closed regardless of the adjuster's rotation. The purpose is to allow the brake shoe to fall violently between the teeth and generate a tapping sound, so that the clearance between the brake shoe and the drum can be adjusted appropriately.

In order to achieve the above-mentioned object, the present invention provides a bolt having a head that is thicker than the hole formed at one end of the lock spring lever, and which has a head that is thicker than the hole formed at one end of the lock spring lever. The lock spring lever can be rotated about the bolt with respect to the body by one bolt which has a plate thickness of Install as you like.

The bolt is arranged so that the engaging portion of the lock spring lever moves in the circumferential direction of the gear portion of the adjuster as the lock spring lever rotates.

A contact part that limits the amount of rotation of the lock spring lever by direct contact with the lock spring lever is formed on the body, and the amount of rotation of the lock spring lever is determined by the amount of movement of the engaging portion that is greater than the tooth gap of the gear part of the adjuster. The settings are as follows.

With this configuration, if you rotate the adjuster.

When the lock spring lever is rotated to one end of its rotational stroke by the engagement between its engaging portion and one tooth of the gear portion of the adjuster, and then the engaging portion of the lock spring lever passes over said one tooth. The lock spring lever rotates toward the other end of the rotation stroke due to the engagement between the 70 engaging part and the one tooth, and the engaging part violently collides with the tooth next to the one tooth, causing the lock spring lever to swivel. generate sound.

Therefore, when it is necessary to adjust the clearance between the brake shoes and the drum when assembling the brake or after driving, insert a screwdriver or other tool into the small hole provided in the backing plate or drum to adjust the gear part of the adjuster. After rotating the brake shoe and extending it until it comes into contact with the drum, when the adjuster's gear is rotated in the opposite direction to return the specified number of teeth, a tapping sound is generated each time the brake shoe is returned to its original position. The clearance between the drum and drum can be adjusted accurately.

The present invention having the above-mentioned structure is inexpensive because there are two parts for attaching the lock spring lever to the body: a bolt and a washer.In addition, since the amount of bolt protruding from the body is small, the bolt and drum brake are attached to the body. This has the advantage that interference with component parts is less likely to occur.

Below, embodiments of the present invention will be described based on the drawings.
In the figure, 1 is a body integrated with the foil cylinder body, and 2 is an adjuster.

The adjuster 2 consists of a stem portion 2a and a gear portion 2b integrally formed at one end of the stem portion 2a.The stem portion 2a is rotatably fitted into an axial cylinder 1a opened at one end of the body 1. The adjuster 2 is supported by the body 1.

3 is the adjuster bolt, screw hole 2 in the center of adjuster 2
c, and is engaged with a brake shoe (not shown) at the left end head portion which is grooved as is well known.

This engagement restricts the rotation of the adjuster bolt 3 as is well known, and also restricts the leftward movement of the adjuster 2 relative to the body 1, and the adjuster bolt 3 moves in the axial direction by 220 rotations of the adjuster to move the brake shoe and brake. Adjust shoe clearance.

Reference numeral 4 denotes a lock spring lever for restricting blind rotation of the adjuster 2, and one end portion 4a of the lock spring lever 4 is attached to the protruding portion 1b of the body 1 with a bolt 6.

This bolt 6 is attached to one end 4 of the lock spring lever 4.
a Washer 5 loosely fitted into K-shaped round hole 4b
It penetrates the inside of the body 1 and is screwed into the body 1.

The head 6a of the bolt 60 has a larger diameter than the round hole 4b of the lock spring lever 4, and the plate thickness β of the washer 5 is thicker than the plate thickness α of the lock spring lever 4.

Therefore, the lock spring lever 4 is rotatable around the bolt 6.

The difference between the plate thickness β and the plate thickness α is that one end 4a of the lock spring lever 4 is connected to the head 6a of the bolt 6 and the protrusion 1b of the body 1.
It is sufficient as long as it can prevent it from being pinched in an unrotatable manner.

The other end of the lock spring lever 4 has a V-shaped cross section (a third
, 4) is provided, and this retaining part 4c
is engaged between the teeth 2d of the gear portion 2b of the adjuster 2 by the elastic force of the lock spring lever 4.

Further, as shown in the second figure, both sides 4a of the one end 4a of the lock spring lever 4 are attached to the side walls 1 of the protrusion 1b.
c and Ic are bent toward the axis of the body 1 with a predetermined interval between them, and when the side portion 4d comes into contact with the side wall 1c, the amount of rotation of the lock spring lever 4 about the bolt 5 is reduced. It is regulated to a predetermined amount.

The amount of rotation of the lock spring lever 4 is such that the forward rotation of the adjuster 2 can be restricted and the amount of movement of the engaging portion 4c is greater than or equal to the tooth gap of the gear portion 2b of the adjuster 2. be.

The operation of the above configuration will be explained next.

In the conditions shown in Figures 1 and 2, move adjuster 2 in one direction (in the direction of the arrow in Figure 3) to adjust the brake shoe clearance.
When the lock spring lever 4 is rotated, the lock spring lever 4 is rotated to one end of its rotational stroke by the engagement of its engaging portion 4c with one tooth of the gear portion 2b of the adjuster 2 as the azimuth rotates 220 degrees.

At this end of the rotation stroke, one side 4d of the lock spring lever 4 comes into contact with one side wall 1cK of the protrusion 1b of the body 1.

Thereafter, as the adjuster 2 continues to rotate, the engaging part 4c of the lock spring lever 4 is displaced radially outward of the gear part 2b due to elastic deformation of the lock spring lever 4, and rides on the teeth of the gear part 2b. rising, engaging part 4c
comes to occupy the position marked ■ in Figure 3.

Thereafter, by further rotating the adjuster 2, the engaging portion 4c is shifted from ■ to ■ in FIG.

When the engaging portion 4c occupies the position (■) in FIG. 3, the elastic force F by which the lock spring lever 4 urges the engaging portion 4c toward the center of the gear portion 2b is applied to the tooth surface as shown in FIG. A component force F2 in the sliding direction and a component force F1 in the direction perpendicular to this are generated.

This component force F generates a frictional force μF1 in the opposite direction to component force F2, but this frictional force is designed to be smaller than component force F2, and the engaging portion 4c has F2−μF1.
The force of F1 acts in the direction of sliding down the tooth surface.

The relationship F > μF is the angle θ and F of each vector of F and F2, μFCO3 (90-θ) < Fcos
It is sufficient to select it so that θ.

Therefore, when the engaging part 4c occupies the positions (■) and (3) in FIG. ■ in Figure 3
When the engaging portion 4c is displaced to the position shown in FIG. 3, the engaging portion 4c moves all at once to the position shown in FIG.

That is, in the first proposed device, when the ■-shaped apex of the engaging portion 4c of the lock spring lever 4 attempts to fall from the top of the teeth 2d of the adjuster 2 to between the teeth, it falls regardless of the rotation of the adjuster 2, producing a tapping sound. Occur.

Of course, even if the adjuster 2 is rotated in the direction opposite to the direction indicated by the arrow in FIG. 3, the same effect will occur since the engaging portion 4c of the lock spring lever 4 has a .beta.-shaped cross section.

In the above-described embodiment, the rotation of the lock spring lever 4 is restricted by the side wall 1 c of the protrusion 1 b of the body 1.
1 cllc is made by bending both sides 4d, 4d of one end 4a of the lock spring lever 4 so that it can come into contact with it, but a protrusion is provided at a position on the outer periphery of the body 1 so as to sandwich the lock spring lever 4. Of course, the purpose of this proposal can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, Figs. (A longitudinal sectional view in (), FIG. 6 is an explanatory diagram of the operation of the conventional device shown in FIG. 5.
: Watsusha, 6: Bolt.

Claims (1)

[Claims for Utility Model Registration] A body to which a backing plate HC of an automobile drum brake is attached, an adjuster rotatably supported by the body and having a gear portion, and a drum brake concentrically screwed to the adjuster. Adjuster bolt engaged with no-flake shoe. One end of the adjuster that is apart from the gear in the direction of the rotational axis is attached to the body, and the engaging part of the other end is engaged with the tooth gap of the gear by its own elastic force, thereby reducing the blindness of the adjuster. A brake shoe clearance adjustment device comprising a lock spring lever that regulates rotation, the bolt having a head that is more dog-shaped than a hole formed at one end of the lock spring lever, and a plate of the lock spring lever. The bolt is screwed into the body through a washer that is loosely fitted in the hole and has a thickness that is slightly larger than that of the lock spring lever. The bolt is mounted so that it can rotate about the center, and the bolt is arranged so that the engaging part moves in the circumferential direction of the gear part of the adjuster as the lock spring lever rotates, and the bolt is arranged so that the engaging part moves in the circumferential direction of the gear part of the adjuster. a contact portion is formed on the body to limit the amount of rotation by directly contacting the lock spring lever, and the amount of rotation of the lock spring lever is such that the amount of movement of the engaging portion is greater than or equal to the tooth gap of the gear portion. Brake shoe clearance adjustment device set.