JPH0519684U - Vehicle drum brake anchor - Google Patents

Abstract

(57) [Abstract] [Purpose] A single plate anchor has high rigidity so as to improve the mounting strength and durability. [Structure] A single high-tensile steel plate is punched in a symmetrical shape, and the anchor 5 is formed by folding it in half from the center. The anchor body 5a and the pedestal portions 5b, 5 are attached to the anchor 5.
b and legs 5c and 5c are provided. The leg portions 5c are inserted into the mounting holes formed in the back plate, respectively, and further bent outward and caulked to fix the anchor 5 to the back plate. The end surface of the web of the brake shoe is brought into contact with and supported by the side end surface 5e of the anchor body 5a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an anchor for a vehicle drum brake that serves as a pivot of a brake shoe.

[0002]

[Prior Art]

 An example of a drum brake anchor is disclosed in Japanese Utility Model Laid-Open No. 2-117438. This anchor consists of an anchor body with which a pair of brake shoes come into contact, ears that prevent the brake shoes from coming off, and legs that are fixed to the back plate. It is integrally formed as a result, and the structure required for the anchor has the effect that it can be manufactured in the punching process of the press.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned one, since the thickness of the metal flat plate that can be punched by the press is limited, the anchor cannot be thicker than the predetermined thickness. For this reason, it was difficult to secure high rigidity in the anchor, and it was not suitable for a drum brake that generates high torque.

Therefore, an object of the present invention is to provide an anchor for a drum brake that can be applied to a high torque drum brake by ensuring high rigidity and mounting strength of an anchor formed of a single plate. I am trying.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the anchor of the vehicle drum brake of the present invention is such that a brake shoe arranged to face a back plate is used as a fulcrum with an anchor provided between one ends as a fulcrum. In a vehicle drum brake that expands and brakes by an actuator installed in the vehicle, the anchor is formed of a metal plate that is folded in half from the center, and legs are projected on both folded end faces of the anchor. It is characterized in that the leg portion is fixed to the back plate and the end portion of the brake shoe is brought into contact with the side end surface of the anchor.

[0006]

[Action]

 With the above structure, both folded back end faces of the folded metal plate are fixed to the back plate, so that the mounting strength can be improved.

[0007] Further, a metal plate having a plate thickness that can be punched by a press can be folded in two to increase the area of the side end surface that contacts the brake shoe.

[0008]

【Example】

 Each embodiment in which the present invention is applied to a drum brake used in a golf car will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention, in which a drum brake 1 is arranged between the ends of arcuate brake shoes 3a and 3b which are arranged inside a back plate 2 so as to face each other. An expansion actuator 4 and an anchor 5 serving as an operation fulcrum of both shoes 3a and 3b are provided.

Since the drum brake 1 of this embodiment is applied to the golf car as described above, the back plate 2 has a small mounting space and therefore has a small diameter relative to the generated torque. Therefore, the braking force required for the golf car is ensured by forming it from a high-strength high-strength steel plate that does not deform even when subjected to high torque.

In one brake shoe 3 a, one end of a shoe web 3 c abuts on a brake lever 4 b pulled by a wire (not shown) and the other end abuts on an anchor 5. In the other brake shoe 3b, one end of the shoe web 3c abuts on the adjusting bolt 4d of the actuator 4 and the other end abuts on the anchor 5. A lining 3e is attached to the outer periphery of the shoe rim 3d of the brake shoes 3a and 3b, and the lining 3e slides on the inner peripheral surface of a brake drum (not shown) rotating in the direction of arrow A in FIG. I do. Further, the brake shoes 3a, 3b are elastically supported by the shoe-hold down pin 6a and the shoe-hold spring 6b at the substantially central portion thereof on the back plate 2 and are attached by the return springs 7, 8 in the radial direction. It is energized.

In addition to the sliding block 4a, the actuator 4 according to the present embodiment includes a brake lever 4b, an adjusting gear 4c, an adjusting bolt 4d extending by rotation of the gear 4c, and one end abutting on the brake lever 4b. , The other end includes an adjusting lever 4e that meshes with the adjusting gear 4c to rotate the adjusting gear 4c, and a spring 4f that elastically engages both levers 4b and 4e. The sliding of the sliding block 4a causes the brake shoes 3a and 3b to expand. Further, when the adjusting gear 4c, the adjusting bolt 4d, the adjusting lever 4e and the spring 4f constitute an auto adjuster and the lining 3e is worn and the braking gap with the brake drum is expanded beyond a predetermined range, The adjustment bolt 4d is extended to regulate the backward movement limit of the brake shoes 3a and 3b so that a predetermined braking gap is automatically obtained.

The anchor 5 is formed by punching a sheet of high-strength steel plate symmetrically by pressing and folding it in half from its central portion. The anchor body 5a with which the brake shoes 3a, 3b abut, It has wide pedestal portions 5b and 5b continuous to both ends of the anchor body 5a, and four leg portions 5c protruding from the respective end portions of the pedestal portions 5b and 5b and fixed to the back plate 2. ..

The attachment of the anchor 5 is carried out by inserting the leg portions 5c into the four attachment holes 2a formed in the back plate 2 and bending the leg portions 5c to the outside by caulking and fixing them to the back plate 2. To do. At this time, the bent portions on the contact side when the leg portion 5c is bent are crushed and inflated to form the ears 5d, 5d for preventing the brake shoes 3a, 3b from coming off. In the brake shoes 3a, 3b, the other ends of the webs 3c are brought into contact with and supported by the side end surface 5e of the anchor body 5a thus mounted. The anchor body 5a of this embodiment is a high-tensile steel plate that is difficult to deep-draw the back plate 2 and has a small amount of projecting deformation to the inside. Therefore, the height of the anchor body 5a and the pedestal portion 5b is smaller than that of the conventional one. It is set so that the webs 3c, 3c of the brake shoes 3a, 3b come into contact with each other at approximately the middle of the height of the anchor body 5a.

In the thus-formed drum brake 1, when the outer end side of the brake lever 4b is rotated rightward in FIG. 1 on the back surface of the back plate 2, the inner end of the lever 4b is moved leftward. The brake shoe 3a on the leading side expands to the left with the anchor 5 as a fulcrum, and the lining 3e slides on the inner peripheral surface of the brake drum. Further, due to this contact reaction force, the sliding block 4a moves to the right, the adjusting bolt 4d pushes the brake shoe 3b on the trailing side to spread it to the right with the anchor 5 as a fulcrum, and the lining 3e of the brake shoe 3b is struck. Apply sliding force to the inner surface of the brake drum on the opposite side for braking.

In the brake shoes 3a and 3b, when the anchor 5 is expanded with the fulcrum as a fulcrum, the anchor main body 5a is formed to have a relatively high height, and the bent portions have the ears 5d. It does not slip up due to the expansion / contraction operation during braking.

In the anchor 5, the four legs 5 c provided at the respective ends of the pedestals 5 b, 5 b are inserted into the respective through holes 2 a of the back plate 2 and further bent outward to form the back plate 2. Since it is mounted, it has good stability and can secure mounting strength and high rigidity. Moreover, since the anchor 5 is formed by folding a high-tensile steel plate having a thickness that can be punched by a press into two, the anchor 5 comes into contact with the webs 3c, 3c more than a conventional anchor formed of a single metal plate. The area of the side end surface 5e can be made large, and stable braking force can be obtained without being deformed even when subjected to a high torque. Further, since the anchor 5 has the above-described effects, it can be applied to not only the drum brake for a golf car such as the present embodiment, which has a large braking force for its size, but also a high torque drum brake. Like

FIG. 5 shows a second embodiment of the present invention. In the anchor 9, the anchor body 9a is formed to have a relatively low height, and the selvage retaining ear 9b is relatively large above the anchor body 9a. The ear portion 9b, which is provided, is integrally formed at the time of punching by a press like other portions.

In the above embodiment, the leg portion of the folded back end face is inserted into the mounting hole formed in the back plate, and the anchor is attached to the back plate by bending outward and crimping. It may be bent inward and caulked, and the legs may be fixed by welding. The bottom surface of the leg may be directly welded to the inner surface of the back plate, and the leg may be bent inward or outward, and the bent leg is fixed to the inner surface of the back plate by welding. But it's okay.

Further, in the above-described embodiment, the back plate and the anchor are formed of the high-tensile steel plate, but the general steel plate may be used.

[0021]

[Effect of the device]

 As described above, according to the present invention, an anchor is formed by a metal plate that is folded in half from the center, and the leg portion of the anchor is fixed to the back plate, and the side end surface of the anchor supports the end portion of the brake shoe. As a result, even if the anchor is formed from a single metal plate, it will be possible to secure sufficient high rigidity and mounting strength for the anchor, making it applicable to high torque drum brakes. Further, since the contact area with the brake shoe can be made larger than that of the conventional one-plate anchor, a stable braking force can be secured and the durability of the anchor can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a drum brake showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view of an anchor.

FIG. 5 is a perspective view of an anchor showing a second embodiment of the present invention.

[Explanation of symbols]

1 ... Drum brake, 2 ... Back plate, 3a, 3b
... brake shoes, 3c ... web, 3e ... lining,
4 ... Actuator, 4a ... Sliding block, 4b ... Brake lever, 4c ... Adjust bolt, 5 ... Anchor,
5a ... Anchor body, 5b ... Pedestal part, 5c ... Leg part, 5d
... Ears, 5e ... Side end faces

Claims (1)

[Scope of utility model registration request] 1. A vehicle in which a brake shoe, which is arranged to face a back plate, is expanded by an anchor provided between one end portions thereof as a fulcrum by an actuator provided between the other end portions to perform a braking action. In the drum brake for a vehicle, the anchor is formed of a metal plate that is folded in two from a central portion, and leg portions are projectingly provided on both folding end surfaces of the anchor, and the leg portions are fixed to the back plate,
An anchor for a vehicle drum brake, wherein an end of the brake shoe is in contact with a side end surface of the anchor.