JPH017864Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a squeal prevention device for drum brakes.

FIG. 1 shows an example of a commonly used drum brake.

The drum brake shown in this figure has a dead band 2 placed on one half of the outer circumference of a drum 1 to be braked, a live band 3 placed on the other half, and a brake band adjustment mechanism having adjustment bolts 4 and 5. , linings 6, 7, 8, 9 spaced apart and riveted to the inner circumference of the dead band 2; linings 10 spaced apart and riveted to the inner circumference of the live band 3; 11, 12, a link 13 for operating the brake band, a lever 14, and a fixed bracket 1 to which the link 13 and lever 14 are attached.
5. The dead band 2 and live band 3 are connected via a brake band adjustment mechanism to form a brake band. The brake band adjustment mechanism is capable of adjusting the roundness of the dead band 2 and the live band 3 and adjusting the brake effectiveness.

In this drum brake, when the lever 14 is pushed in the direction of arrow a, the brake band composed of the dead band 2 and the live band 3 is tightened, and the linings 6 to 12 are pressed against the outer peripheral surface of the drum 1. Friction occurs between the drum 12 and the drum 1, and the drum 1 is braked.

Here, the lining 6 fixed to the end of the dead band 2 on the link 13 side is different from the lining 7 fixed to the other position of the dead band 2,
Compared to 8 and 9, it is always at the forefront of drum braking.
Furthermore, the lining 10 fixed to the end of the live band 3 on the brake band adjustment mechanism side is also at the forefront of drum braking compared to the linings 11 and 12 fixed to other positions of the live band 3. be.

For this reason, when the drum 1 is braked, stake slip occurs mainly in the linings 6 and 10 located at the most extreme end of the drum brake.
This static slip is a phenomenon in which the end of the lining repeats braking → slipping → braking → slipping between the end of the lining and the braking surface. This causes the brake band to vibrate, and the resonance is transmitted to the drum 1, brake cover, etc. Produces a squealing sound.

This squealing sound is extremely difficult to hear and harsh, which causes noise pollution. As a result, this may lead to complaints about the location where the machine is being operated, making it difficult to operate the machine.

On the other hand, in the prior art, as shown in FIGS.
As shown in the figure, tapered surfaces 19 are formed at both longitudinal ends of the drum-side surface 17 of the lining body 16 to prevent stick slips from occurring, and the vibrations caused by stick slips can be suppressed. No measures have been taken to absorb it. Therefore, when performing half braking with the drum brake to which the linings 6 to 12 are attached,
This brake squeal has become a major problem in construction machinery such as ground drills and clamshells, which cannot avoid squealing noise and repeatedly brake.

SUMMARY OF THE INVENTION An object of the present invention is to provide a squeal prevention device for drum brakes that can absorb the vibrations caused by the sticks and slips as described above, prevent vibrations of the brake band, and effectively prevent squealing noise.

The feature of the present invention is that, in the drum brake as described above, grooves for vibration absorption by stay slips are provided only at both ends of the side of the lining that contacts the brake band, and this structure achieves the above purpose. can be achieved.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

4, 5, and 6 show an embodiment of the present invention, in which the surfaces 18 of the lining bodies 16 of the linings 6 to 12 on the side in contact with the brake band are provided with vibration absorbing devices using stakes and slips. A groove 20 is provided.

The grooves 20 for vibration absorption by the stay and slip are provided only at both ends of the lining body 16 in the length direction, and a large number of grooves 20 at each end are formed at intervals in the length direction of the lining body 16. has been done.

Incidentally, a tapered surface 19 is formed at both lengthwise ends of the drum-side surface 17 of the lining body 16, as in the conventional case, and a plurality of attachment holes 21 are provided in the lining body 16.

The overall configuration of the drum brake shown in FIG. 4 is the same as the drum brake shown in FIG. 1, and the same members as those of the drum brake in FIG. omitted.

Since the drum brake squeal prevention device according to the present invention is constructed as described above, when the lining body 16 vibrates due to stakes and slips during braking, the longitudinal direction of the surface 18 of the lining body 16 in contact with the brake band The vibrations are absorbed by the elasticity of the protrusions on both sides of the multiple grooves 20 provided at both ends, thereby preventing the brake band from vibrating. In this manner, the present invention can effectively absorb the vibrations generated by the stake slip, which is the source of the squealing noise, so that brake squeal can be prevented.

In addition, in the present invention, the lining body 16
Since the grooves 20 are provided only at both lengthwise ends of the surface 18 in contact with the brake band, machining after forming the lining body 16 is easy, and the mechanical strength of the lining body 16 can be reduced to almost nothing. It will not be lowered.

In addition, in the embodiment shown in FIG.
12 are all equipped with grooves 20 for vibration absorption due to stay slips.
Grooves 20 for absorbing vibrations caused by stakes and slips may be provided only in the linings 6 and 10 at positions where stakes and slips start during braking.

As described above, according to the present invention, grooves are provided on the sides of the lining that come into contact with the brake band at both longitudinal ends, and vibrations caused by sticks and slips are absorbed by the elasticity of the protrusions on both sides of the grooves. ,
Since the vibration is prevented from being transmitted to the brake band, squealing noise due to brake slip is prevented from occurring, and noise pollution caused by brake squeal can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a generally used drum brake, FIG. 2 is an enlarged partially cutaway front view of a conventional brake lining, and FIG. 3 is a side view of the same. Figure 4 is a front view showing an example of a drum brake to which the squeal prevention device according to the present invention is applied;
The figure is an enlarged partially cutaway front view of the lining according to the present invention, and FIG. 6 is a side view of the same. 1...Drums, 2...Dead band constituting the brake band, 3...The same live band, 6-1
2...Lining, 16...Lining body, 1
8... The surface of the lining that comes into contact with the brake band, 20... Groove for vibration absorption by stay sticks and slips.

Claims (1)

[Scope of utility model registration request] In a drum brake configured such that a lining divided into a plurality of parts is fixed to the inner circumference of a brake band, and when the brake band is tightened, the lining is brought into pressure contact with the outer circumferential surface of a drum to perform braking, the side of the lining in contact with the brake band 1. A squeal prevention device for a drum brake, characterized in that grooves for absorbing vibrations due to stays and slips are provided only at both ends of the surface of the drum brake.