JPS6141453Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention involves passing a strut between a pair of brake shoes that are biased toward each other by a return spring so that the shoe web is received at the gripping part of the brake shoe, and then the strut is attached to an adjustment gear. It extends by rotation to adjust the braking gap, and at the same time rotates the parking brake lever parallel to the shoe web to push the grip part of the strut.
This invention relates to a drum brake device for a vehicle that applies a parking brake by expanding both brake shoes.

In this type of vehicle drum brake device, the gripping part of the strut on the side to which the parking brake lever is pivoted is installed so that it straddles the show web and the parking lever, but in this type of mounting structure, , an assembly gap is required to receive and fit the gripping part of the strut, the shew web, and the parking brake lever, and this gap is created between the gripping part of the strut, the shew web, and the parking brake lever, and the strut rotates. There is. The rotation of this strut became unsteady, causing noise, and the adjustment gear rotated with the strut, resulting in poor adjustment.

Furthermore, the adjustment gear is rotated by the adjustment lever to extend the strut and adjust the braking gap, but when the adjustment lever returns, the adjustment gear is brought back, causing problems such as the adjustment not being performed reliably. There was a problem.

The present invention was developed against the background of this situation, and includes a retainer member interposed between the strut's gripping part and the show web, so that the first arm and the second arm can straddle and slide between the show web and the parking brake lever. A third arm and a fourth arm extending in a direction opposite to the first arm and the second arm are brought into close contact with both side surfaces of the strut, and one arm is engaged with the teeth of an adjustment gear, The purpose of this is to use a retainer member to regulate the rotation of the strut and hold it without rattling, and also to prevent the adjustment gear from reversing, thereby solving the above problems.Furthermore, it is possible to do all of this with a single member, reducing the number of parts and assembling the strut. An object of the present invention is to provide a brake device for a vehicle that can improve the working efficiency of the vehicle.

An embodiment of the present invention will be described below with reference to the drawings.

A pair of brake shoes 2, 2 having brake linings 2a, 2a are arranged on a back plate 1 fixed to the vehicle body, and one end of this brake shoe 2, 2 is connected to a piston 4, 4 of a wheel cylinder 3. , the other end abuts on the anchor 5,
They are urged toward each other by a return spring 6. Then, when pressure fluid is supplied from a master cylinder (not shown) to operate the pistons 4, 4, the brake shoes 2, 2 resist the return spring 6 and move the linings 2a, 2a to the brake drum (not shown). It is designed to come in sliding contact with the A parking brake lever 7 is provided at the lower part of the shoe web 2b of the trailing side brake shoe 2 so as to be rotatable about a pivot 8 as a fulcrum.

And between the pair of brake shoes 2, 2,
The first strut 9 having a female threaded portion 9a is fitted with its gripping portion 9b so as to straddle the trailing side shew web 2b and the parking brake lever 7, and the second strut 10 having a cylindrical portion is fitted over its gripping portion 10a. is fitted into the leading side shew web 2b, and furthermore, the adjustment gear 11a
The adjusting member 11 having the male threaded shaft portion 1
1b is screwed into the female threaded portion 9a of the first strut 9, and its straight shaft portion is inserted into the second strut 10 so as to be freely rotatable. Thereby, the distance between the two brake shoes 2, 2 is maintained, and the rotation of the adjustment lever 12 rotates the adjustment gear 11a to extend the first strut 9 and the second strut 10.

The adjustment lever 12 is rotatably provided on the shew web 2b on the leading side, and the projecting piece 12a abuts the end of the grip part 10a of the second strut 10, and the claw part 12b is connected to the adjustment gear 11a.
It meshes with the The adjustment lever 12 is biased inward of the back plate 1 by an adjustment spring 13 whose one end is locked to the shew web 2b, and the claw portion 12b is pressed against the adjustment gear 1.
1a, and is rotated by the expansion of the brake shoes 2, 2, thereby rotating the adjustment gear 11a.

Grip part 9 of the first strut 9 on the training side
As shown in FIG.
A first arm 13b and a second arm 13c extend in a wavy manner in one direction from the upper and lower ends of the base 13a.
and the first arm 13 from both ends of the base 13a.
It has a third arm 13d that extends straight in the opposite direction to the second arm 13c and a fourth arm 13e that extends longer than the third arm 13d.

The base portion 13a of the retainer member 13 is interposed between the side wall of the grip portion 9b of the first strut 9 and the side surfaces of the show web 2b and the parking brake lever 7, and the first arm 13b and the second arm 13c are connected to the show web 2b. It straddles the parking brake lever 7, and the upper and lower bent portions 13f of the first arm 13b are connected to the upper wall of the gripping portion 9b and the show web 2b, and the upper and lower bent portions 13g of the second arm 13c are connected to the lower wall of the gripping portion 9b. Parking brake lever 7
are interposed in pressure contact with each other so as to be elastically deformable. The first arm 13b and the second arm 13c are in pressure contact with the shew web 2b and the parking brake lever 7 so as not to apply a load, so that when the parking brake is activated, the parking brake lever 7 can rotate smoothly and the first arm 13b At the same time, the first strut 9 can be slid on the shew web 2b and pushed through the base 13a.

The third arm 13d and the fourth arm 13e are closely held on both sides of the first strut 9,
The tip of the fourth arm 13e further engages with the adjustment gear 11a so as to restrict reverse rotation.

Next, the operation of this embodiment will be explained.

When pressurized fluid is supplied to the wheel cylinder 3 by operating the brake pedal, both brake shoes 2, 2
are pushed and expanded by the pistons 4, 4, and the respective linings 2a, 2a are brought into sliding contact with the brake drum to perform braking. And lining 2a,
As the adjustment lever 2a wears, the adjustment lever 12, which is biased by the adjustment spring 14, rotates in the direction A and rotates the adjustment gear 11a. As a result, the first strut 9 and the second strut 10 extend to widen the brake shoes 2, 2, and adjust the braking gap between the linings 2a, 2a and the brake drum to be always constant.

At this time, the first strut 9 is connected to the retainer member 1.
a first arm 13b and a second arm 13c that straddle the show web 2b of No. 3 and the parking brake lever 7;
Since the third arm 13d and the fourth arm 13e, which extend in the opposite direction and are in close contact with both sides of the first strut 9, are held while restricting rotation and vibration, the adjustment lever 12 is held by the adjustment gear 1.
When rotating 1a, the first strut 9 does not rotate together with the adjustment gear 11a. Therefore, the adjustment lever 12 reliably rotates the adjustment gear 11a, and accurate adjustment operation is performed. Further, the adjustment lever 12 that has rotated the adjustment gear 11a may take the adjustment gear 11a back and reverse the adjustment when returning, but this reversal of the adjustment gear 11a can be reliably prevented by the fourth arm 13e of the retainer member 13, and the braking gap can be prevented. automatic adjustment is performed accurately.

Next, parking brake operation will be explained.

When the parking brake lever 7 is rotated by the manual brake mechanism in the direction B in FIG. The gripping portion 9a of the first strut 9 is pressed via the lever 13a, the first strut 9, the adjusting member 11 and the second strut 10 are moved, and the leading side brake shoe 2 is expanded to perform braking. At this time,
First arm 13b and second arm 1 of retainer member 13
3c is in slidable pressure contact between the show web 2b and the parking brake lever 7, so the parking brake lever 7 operates smoothly without flapping, and the show web 2b and the side part of the parking brake lever 7 are strutted together via the base 13a. Since it is in contact with the gripping portion 9b of No. 9, the contact surfaces between the two will not be scuffed or damaged even by repeated operations, and can operate satisfactorily for a long period of time.

Since the present invention is constructed as described above, the strut that maintains the distance between the pair of brake shoes and expands by the rotation of the adjustment gear to adjust the braking gap is held so as not to rotate or vibrate. The adjustment gear no longer rotates with the strut when the adjustment is activated.
The rotation of the adjustment gear by the adjustment lever is accurate, and since the adjustment gear does not reverse as the adjustment lever returns, the braking gap can be adjusted stably and with high precision.

Further, the prevention of rotation and vibration of these struts and the prevention of reverse rotation of the adjustment gear can be achieved by one member of the retainer member, and the manufacturing cost is low and assembly is easy.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view, FIG. 2 is a cross-sectional view of FIG. 1, and FIG.
The figure is a perspective view of the retainer member. 1 is a back plate, 2, 2 are brake shoes, 2b, 2b are shoe webs, 9 is a first strut, 9b is a gripping portion, 10 is a second strut, 1
1 is an adjustment member, 11a is an adjustment gear,
12 is an adjustment lever, 12b is a claw portion, 13 is a retainer member, 13a is a base portion, 13b is a first arm,
13c is the second arm, 13d is the third arm, 13e is the fourth arm
It's an arm.

Claims (1)

[Scope of utility model registration request] A strut, which maintains the distance between the two brake shoes and adjusts the braking gap by rotation of the adjustment gear, is placed between a pair of brake shoes that are urged in the proximal direction by a return spring. When the parking brake lever is pivoted to one shoe web and the parking brake lever is pivoted to the other shoe web, the holding part of one strut is pressed to widen the gap between the brake shoe and the strut and both brake shoes are moved. A drum brake device for a vehicle that is brought into contact with a brake drum includes a first arm and a second arm extending in one direction from the upper and lower ends of a base, and a first arm and a second arm extending in a direction opposite to the first and second arms from both ends of the base. A retainer member having a third arm and a fourth arm extending out is interposed between the gripping portion of the strut and the show web, and the first arm and the second arm straddle the show web and the parking brake lever, and each of the retainer members is provided on both sides. A vehicle characterized in that the third arm and the fourth arm are in close contact with both sides of the strut, and one arm is engaged with the teeth of an adjustment gear so as to restrict reverse rotation of the adjustment gear. drum brake device.