JPH022489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an improvement in a shoe for a drum brake that is incorporated in a drum brake used for braking an automobile and that presses a lining against the inner peripheral surface of a drum that rotates together with a wheel during braking.

(Background technology) Drum brakes used for braking automobiles are
For example, as shown in FIG. 1, a pair of left and right shoes 2, 2 is provided inside a drum 1 that rotates together with the wheels, and a hydraulic cylinder 5 is provided with one end of the webs 3, 3 of both shoes 2, 2 during braking. piston rod 6,
An anchor 8 is fixed to the opposite end of the hydraulic cylinder 5 on the back plate 7 so that both shoes 2, 2 are fixed to the opposite end of the hydraulic cylinder 5 on the back plate 7.
The linings 4, 4 attached to the outer periphery of the shoes 2, 2 are firmly pressed against the inner peripheral surface of the drum 1 by pushing them outward while rotating the web 3 (in some cases, one end of the web 3 is pivotally supported). It is configured to perform braking by pressing.

Incidentally, the shoe 2 incorporated in the drum brake configured and operated as described above vibrates finely due to the friction between the inner circumferential surface of the drum 1 and the outer circumferential surface of the lining 4 during braking, and generates a noise called squeal. . As a result of the inventor's research on the mechanism of noise generation due to this vibration, it was found that this noise is mainly caused by vibrations of the back surface fixed to the outer peripheral edge of the web 3 to which the lining 4 is attached. That is, as shown in FIGS. 2 and 3, a shoe 2 is provided in which a backing metal 9 is fixed to the outer peripheral edge of a substantially crescent-shaped web 3, and a lining 4 is attached to the outer peripheral surface of this backing metal 9.
When the lining 4 rubs against the inner circumferential surface of the drum 1 during braking, the backing metal 9 moves in opposite directions at the joint with the web 3 and at a portion slightly closer to the center from both ends. vibrate toward
Generates noise. In FIG. 3, chain lines a and a indicate portions serving as nodes of vibration, and the diagonal lattice portions and the white portions indicate that the directions (phases) of vibration are opposite to each other.

Shu 2 uses the mechanism described above to release the back metal 9 during braking.
vibrates and generates noise. However, in the conventional shoe 2, the web 3 was formed into a flat plate shape, and the part of the web 3 that contacted the back metal 9 was straight.
The nodes of vibration were formed in an orderly manner, making the back metal 9 easy to vibrate.

In addition, some wide shoes 2 used in large vehicles have two webs 3, 3 parallel to each other fixed to the inner peripheral surface of the back plate 9;
Even in the case of a drum brake shoe having two webs 3, 3, as shown in FIG. 4, vibration nodes were formed in an orderly manner, making the back plate 9 easy to vibrate.

(Object of the present invention) In order to prevent the above-mentioned noise generation, the present invention provides a shoe for a drum brake that does not easily vibrate even when the outer circumferential surface of the lining rubs against the inner circumferential surface of the drum during braking. It is an object.

(Structure of the present invention) The drum brake shoe of the present invention has a generally crescent-shaped web 3 fixed to the inner circumferential surface of a back metal 9 to which a lining 4 is attached to the outer circumferential surface, and is formed into a curved plate shape. By making the contact portion with the back metal 9 curved, vibration nodes are prevented from being formed in an orderly manner on the back metal 9, and the back metal 9 vibrates due to the friction between the inner peripheral surface of the drum and the lining during braking. It was made to be difficult.

(Embodiments of the present invention) Next, the present invention will be explained in more detail while explaining embodiments shown in the drawings.

FIG. 5 shows a first embodiment of the invention. In this embodiment, the present invention is applied to a normal one-web shoe 2. The web 3 fixed to the inner circumferential surface of the back surface 9 is formed into a curved plate shape, and the web 3 and the back metal 9 are connected to each other. The contact portion has a curved shape.

Since the drum brake shoe of the present invention is constructed as described above, even if the back metal 9 attempts to vibrate, the nodes of vibration will have a complicated curved shape as shown by chain lines b and b in FIG. itself becomes difficult to vibrate.

Next, FIGS. 6 and 7 show second and third embodiments of the present invention, in which the present invention is applied to a two-web shoe for a large vehicle. In any of the embodiments, each web 3, 3 is formed into a curved plate shape, and the contact portion between the webs 3, 3 and the back metal 9 is curved, but in the second embodiment shown in FIG. In the example, steps are formed at two locations on each web 3, 3,
The distance between the central portions of each web 3, 3 is wider than that at both end portions, and in the third embodiment shown in FIG. 7, a stepped portion is formed at one central portion of each web 3, 3. However, the interval between one end of each web 3, 3 is made wider than the interval between the other ends. The distance between the webs 3, 3 may be widened either on the piston rod side or on the anchor side. In the second and third embodiments as well, since the abutting portions between the webs 3, 3 and the backing metal 9 are curved, the vibration nodes of the backing metal 9 have a complicated curved shape, and the backing metal 9 It becomes difficult to vibrate.

(Effects of the present invention) As described above, the drum brake shoe of the present invention has a simple structure that can effectively prevent the generation of noise caused by vibration during braking, and is newer than the conventional one. Since there are no additional parts required, there is no need to increase costs.

[Brief explanation of drawings]

Figure 1 is a side view of a drum brake, and Figures 2 to 4 show conventional drum brake shoes.
Figure 2 is a side view, Figure 3 is the first example, Figure 4 is the second example.
View from the right of Figure 2 and Figure 5, respectively, showing examples.
7 are diagrams similar to FIGS. 3 to 4, respectively, showing the first to third embodiments of the present invention. 1: drum, 2: shoe, 3: web, 4: lining, 5: hydraulic cylinder, 6: piston rod,
7: Back plate, 8: Anchor, 9: Back metal.

Claims (1)

[Claims] 1. In a drum brake shoe in which a lining 4 is attached to the outer peripheral surface of a back metal 9 fixed to the outer peripheral edge of a substantially crescent-shaped web 3, by making the web 3 into a curved plate shape, the web 3 and A drum brake shoe characterized in that the contact portion with the back metal 9 is curved.