JPS5940023A - Shoe for drum brake - Google Patents

Abstract

PURPOSE:To prevent the generation of noise during the braking operation by forming a slit-shaped slot or projection at a part of a back metal attaching a lining. CONSTITUTION:A plurality of slit-shaped slots 10 are formed at left and right sides from the back metal fixed at its inner peripheral surface with a web 3. Accordingly, the rigidity of the back metal 9 is slightly reduced as compared with the case where the slot 10 is not formed. Even when the lining 4 attached to the outer peripheral surface of the back metal 9 rubs against the inner peripheral surface of the drum 1, and the entire shoe apts to vibrate, the back metal 9 does not resonate, and a large noise is not generate during the braking operation. In place of the slot 10, a projection may be provided.

Description

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

(Background Art) As shown in FIG. 1, for example, a drum brake used for braking an automobile is provided with a pair of left and right shoes 2.2 inside a drum 1 that rotates together with the wheels. The piston rod 6.6 of the hydraulic cylinder 5, which is in contact with one end of the web 3.3 of the shoe 2.
2 is fixed to the opposite end of the hydraulic cylinder 5 on the back plate 7, and pushed outward while rotating around the anchor 8 (in some cases, one end of the web 3 is pivoted).
．． The lining 4.4 attached to the outer periphery of the drum L
It is configured to perform braking by strongly pressing against the inner circumferential surface of the brake.

Incidentally, the shoes 2 incorporated in the drum brake constructed and operated as described above vibrate 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 generate 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 due to the vibration of the back metal 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, in a shoe 2 in which a back 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 back metal 9, the lining is removed during braking. 4 rubs against the inner circumferential surface of the drum 1, the back metal 9 becomes a node at the joint with the web 3 and a portion slightly closer to the center from both ends, and both sides of the back metal 9 turn in opposite directions, causing vibration 17 and noise. occurs.

In Fig. 3, the chain 1fi as a indicates the vibration node 4), and the diagonal lattice part and the white part indicate that the direction C phase of the JR motion is opposite to each other. There is.

When the shoe 2 is braked, the back metal 9 vibrates due to the above-mentioned mechanism and generates noise, but in the conventional shoe 2, the back metal 9 resonates with the vibration of the entire shoe and tends to vibrate. .

Some wide shoes 2 used for large-sized vehicles have two parallel webs 3.3 fixed to the inner circumferential surface of the back plate 9; 3, vibration nodes are formed in an orderly manner as shown in FIG.
easily resonated with the vibration of the entire shoe.

c) Purpose of the present invention) The present invention aims to prevent the above-mentioned noise from occurring.
To provide a shoe for a drum brake that does not easily vibrate even when the outer circumferential surface of a lining rubs against the inner circumferential surface of a drum during braking.

(Structure of the present invention) In the drum brake shoe holder of the present invention, a part of the back metal 9 to which the lining 4 is attached to the outer circumferential surface is formed with a slit-like cut or a protrusion, so that the back metal 9 can be attached to the shoe during braking. This prevents noise from occurring during braking by making it difficult to resonate with the vibrations of the brake.

(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.

Web 3.3 of back metal 9 with web 3.3 fixed to the inner peripheral surface
Ki: J multiple slit-like cuts 10 on the left and right sides than
, forming the IO. For this reason, the rigidity of the back metal 9 is slightly lowered compared to the case where the notches 10 and 10 are not formed, and the lining 4 (Fig. 2) attached to the outer peripheral surface of the back metal 9 has friction with the inner peripheral surface of the drum J. Even when the entire shoe tries to vibrate, the back metal 9 does not resonate and no large noise is generated during braking.

Next, FIGS. 6 to 8 show second to third practical examples of the present invention. In all of these embodiments, protrusions 11.11 are formed on both sides of the web 3.30 on the inner peripheral surface of the back metal 9. il
In the second embodiment shown in FIG.
．． 30 A plurality of ridges are formed in the width direction of the back metal 9 at right angles to the protrusions 11 formed in the length direction of the back metal 9 at the center of both sides, and the ridges extending in the width direction The numbers are different on the left and right. In addition, in the third practical example shown in FIGS. 7 and 8, as in the above-mentioned first embodiment, a backing plate 9 is formed in the longitudinal direction at the center of both measuring portions of the web 3.3. A plurality of ridges are formed across the width direction of the back plate 9 so as to be perpendicular to the ridges 11, but in the third embodiment shown in FIG. are the same,
In the fourth embodiment shown in FIG. 8, contrary to the second embodiment shown in FIG. 6, the number of protrusions in the width direction is larger on the right side than on the left side. - Moreover, the number of protrusions in the width direction itself is reduced.

As shown in FIG. 9, the shape of the protrusion in the practical example of λ1 and others is as follows: 1. A narrow plate material is fixed to the back surface of the back metal 9 by welding. Alternatively, as shown in FIG. 10, the back metal 9 itself may be bulged toward the back surface. As a result of forming such a protrusion 11 on the back surface of the back metal 9,
The rigidity of the back metal 9 is slightly improved, and even if the lining 4 attached to the outer peripheral surface of the back metal 9 rubs against the inner peripheral surface of the drum 1 and the entire shoe tries to vibrate, the back metal 9 will not resonate. As in the case of the first embodiment described above, it is possible to prevent large noises from being generated during braking. Since the noise associated with resonance is suppressed, the noise generated during braking can be reduced compared to conventional models.

In addition, in order to change the rigidity of the back metal 9, the notches 10 and ridges 11 are formed in the part where the back metal 9 which does not have these cuts etc. should vibrate when it vibrates. The effect is large.

[Brief explanation of drawings]

Figure 1 is a side view of the Dorado brake, Figure 2 is a side view of a conventional shoe, and Figure 3 is a view from the right side of Figure 2, showing a first example of the vibration state of the back metal of the shoe during braking. Figure 4 is a diagram similar to Figure 3 showing the second example, Figures 5 to 8 are diagrams similar to Figure 3, and Figures 5 to 8 illustrate the first to first practical examples of the present invention, respectively. FIG. 10 is an enlarged view of the wing A in FIG. 6 showing two examples of the protrusions. 1; drum, 2: shoe, 3. Web, 4 lining, 5: vertical pressure cylinder, 6 niviston rod, 7: back plate, 8: anchor, 9z back metal, JO: notch, 11: protrusion. Patent applicant: Akebono Bregi Industry Co., Ltd. Representative
Kinzo Koyama (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4 Figure 12 Figure 5 Figure 6 Figure 9 Figure δ

Claims (1)

[Claims] A back metal (9) fixed to the outer periphery of the approximately crescent-shaped web (3)
), a drum brake shoe has a lining (4) attached to the outer circumferential surface of the web (3), and a notch (JO) or protrusion (
11) A drum brake shoe characterized in that the rigidity of the back metal (9) forming the lever is changed.