Vibration-damping and noise-reducing brake disc

Abstract

The present invention discloses a vibration-damping and noise-reducing brake disc, where the vibration-damping and noise-reducing brake disc includes an intermediate disc having an outer side and a braking ring which surrounds the outer side of the intermediate disc. Two opposite surfaces of the braking ring are frictional surfaces provided with at least one laser scanning strip, where the laser scanning strip is obtained or formed by laser quenching and hardening treatments of the two frictional surfaces by a laser machine, for changing the physical and mechanical properties of the braking ring, such as the surface and inside hardness, residual stress distribution on the frictional surfaces, and the inside micro-structures of the braking ring, so as to suppress the generation of frictional vibration and noise during braking operations. The vibration-damping and noise-reducing brake disc of the present invention has stable coefficients of friction in braking operations, therefore, the occurrence of frictional noise and vibrations of the brake disc can be reduced, and the operational performance of the vehicle with such brake discs can be improved.

Claims

1. A vibration-damping and noise-reducing brake disc, comprising: an intermediate disc having an outer side; and a braking ring surrounding the outer side of the intermediate disc and having two opposite frictional surfaces each provided with at least one laser scanning strip, the laser scanning strip being formed by laser quenching and hardening treatments of the two frictional surfaces by a laser, for changing a residual stress distribution on the frictional surfaces and inside micro-structures of the braking ring, so as to suppress the generation of frictional vibrations and noise during braking operations.

2. The vibration-damping and noise-reducing brake disc according to claim 1, wherein the laser for quenching and hardening treatments has a laser scanning power in a range of 500-4000 W, a scanning speed in a range of 100-1000 mm/min, and a laser spot area in a range of 10-100 mm.sup.2.

3. The vibration-damping and noise-reducing brake disc according to claim 1, wherein the laser scanning strips comprise an annular shape and are sequentially distributed from the inside to the outside in the radial direction of the braking ring, and a center of the laser scanning strips coincides with a center of the intermediate disc.

4. The vibration-damping and noise-reducing brake disc according to claim 1, wherein the laser scanning strip is strip-shaped laser scanning strips extending in the radial direction or parallel distributed on the surfaces of the braking ring.

5. The vibration-damping and noise-reducing brake disc according to claim 1, wherein a material of the brake disc comprises cast iron and can also be any other materials that can be used as brake discs.

6. The vibration-damping and noise-reducing brake disc according to claim 1, wherein the brake disc is used in vehicles and can also be used in any other machines and equipment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic structural view of a vibration-damping and noise-reducing brake disc according to an embodiment of the present invention;

(2) FIG. 2 is a curve chart that shows the relationship between the friction coefficient of the vibration-damping and noise-reducing brake disc and the braking pressure and time according to an embodiment of the present invention;

(3) FIG. 3 is a comparison view of axial vibration signals in one cycle of braking noise tests of the brake disc without laser quenching; and

(4) FIG. 4 is a comparison view of axial vibration signals in one cycle of braking noise tests of the brake disc after laser quenching according to an embodiment of the present invention.

DETAILED DESCRIPTION

(5) In order to make the technical means and effects of the present invention easy to understand, the present invention will be specifically described below in conjunction with the embodiments and the accompanying drawings.

Embodiments

(6) FIG. 1 is a schematic structural view of a vibration-damping and noise-reducing brake disc according to an embodiment of the present invention; and FIG. 2 is a birdview of the vibration-damping and noise-reducing brake disc according to an embodiment of the present invention.

(7) As shown in FIG. 1, a vibration-damping and noise-reducing brake disc 100 of this embodiment includes an intermediate disc 10 and a brake ring 20.

(8) The brake ring 20 surrounds the outer side of the intermediate disc 10; and two opposite surfaces of the brake ring are friction surfaces provided with at least one laser scanning strip 21.

(9) The laser scanning strip 21 is obtained by laser quenching and hardening treatment of the two frictional surfaces, for changing the residual stress distribution on the frictional surfaces, so as to suppress the generation of frictional vibration and noise during braking.

(10) The laser scanning power for the laser quenching and hardening treatment is 500-4000 W, the scanning speed is 100-1000 mm/min, and the laser spot area is 10-100 mm.sup.2.

(11) The laser scanning strips 21 have an annular shape and are sequentially distributed from the inside to the outside in the radial direction of the brake ring, and the center of the circle coincides with the center of the intermediate disc.

(12) When the number of the laser scanning strips 21 is more than one, the laser scanning strips are sequentially evenly distributed or unevenly distributed from the inside to the outside in the radial direction or parallel distributed on the surfaces of the brake ring.

(13) FIG. 2 is a curve chart, which shows that the friction coefficient of the vibration-damping and noise-reducing brake disc is varying with the braking pressure and time according to the embodiment of the present invention.

(14) As shown in FIG. 2, when the initial braking speed is 50 km/h and the braking temperature is 150° C., the braking friction coefficient μ is kept nearly a constant value of 0.35 as the braking pressure and braking time is increasing.

(15) The braking frictional noise tests were performed with the non-quenched brake disc and the vibration-damping and noise-reducing brake disc 100 of the embodiment. The sound pressure levels in the frequency range of 2 kHz to 16 kHz of 185 braking tests were analyzed.

(16) Table 1 presents the occurrence numbers of large braking sound pressure levels generated by the brake disc without laser surface quenching. It can be seen from Table 1 that, over 70 dB(A) sound pressure levels are observed in 25 braking tests that accounts for 13.51% of the 185 total braking tests; over 80 dB(A) sound pressure levels are observed in 20 braking tests that accounts for 10.81% of the 185 total braking tests; over 90 dB(A) sound pressure levels are observed in 10 braking tests that accounts for 5.41% of the 185 total braking tests.

(17) TABLE-US-00001 TABLE 1 Large sound pressure level of braking tests generated by the brake disc without laser surface quenching Sound pressure level Occurrence Proportion Frequency range dB(A) number % 2 kHz to 16 kHz >70 25 13.51 >80 20 10.81 >90 10 5.41 >100 0 0 Total braking operations 185

(18) Table 2 shows the occurrence numbers of large braking sound pressure levels generated by the brake disc with laser surface quenching. It is observed from Table 2 that, over 70 dB(A) sound pressure levels are observed in 7 braking tests that accounts for 3.8% of the 185 total braking tests; over 80 dB(A) sound pressure levels are observed in 4 braking tests that accounts for 2.2% of the 185 total braking tests; over 90 dB(A) sound pressure levels are observed in 1 braking test that accounts for about 0.5% of the 185 total braking tests.

(19) TABLE-US-00002 TABLE 2 Large sound pressure level of braking tests generated by the brake disc with laser surface quenching Sound pressure level Occurrence Proportion Frequency range dB(A) number % 2 kHz to 16 kHz >70 7 3.8 >80 4 2.2 >90 1 0.5 >100 0 0 Total braking operations 185

(20) It can be seen from the braking noise test results shown in Table 1 and Table 2 that, the braking frictional noise has been significantly reduced by the laser quenched brake disc in this embodiment.

(21) FIG. 3 demonstrates the axial acceleration signals of a caliper in one operation of a braking frictional noise test generated by a brake disc without laser surface quenching; while FIG. 4 illustrates the axial acceleration signals of a caliper in one operation of a braking frictional noise test generated by the brake disc with laser surface quenching, a vibration-damping and noise-reducing brake disc according to an embodiment of the present invention.

(22) As shown in FIG. 3 and FIG. 4, compared with the brake disc without laser surface quenching, the vibration-damping and noise-reducing brake disc 100 in the embodiment generates a much lower vibration acceleration amplitude, indicating that the vibration-damping and noise-reducing brake disc 100 in this embodiment can significantly reduce braking vibrations, and the maximum amplitude of braking vibrations of the vibration-damping and noise-reducing brake disc 100 is reduced by more than 90%.

Function and Effect of Embodiments

(23) According to the vibration-damping and noise-reducing brake disc of the embodiment, since the laser scanning strip of the friction surface is substantially a thin quench-hardened layer, the frictional surfaces have fine uniformed micro-structures, so that the good toughness inside the brake disc is ensured and the brake disc has a stable coefficient of friction, and the damping performance of the brake disc is also improved. Therefore, the vibration-damping and noise-reducing brake disc of the present invention can reduce the occurrence of friction noise and vibration of the brake disc and improve the braking performance of a vehicle.

(24) According to the vibration-damping and noise-reducing brake disc of the embodiment, since the frictional surfaces is subjected to laser quenching and hardening treatments, the laser scanning strip is obtained; and the laser surface treatment is convenient without modifying the structure of the brake, which is very easy to implement.

(25) The above embodiments are preferred examples of the present invention and are not intended to limit the scope of the present invention.

(26) For example, in the above embodiment, the laser scanning strips have an annular shape, and the center of the laser scanning strips coincide with the center of the intermediate disc and the laser scanning strips are sequentially distributed from the inside to the outside in the radial direction of the braking ring, thereby ensuring good toughness inside the brake disc while making it have a stable friction coefficient, and improving its damping performance; in the present invention, the laser scanning strips may also be strip-shaped laser scanning strips extending in the radial direction of the braking surfaces or parallel distributed on the braking surfaces, which can also ensure good toughness inside the brake disc while making it have stable friction coefficients, and improving its damping performance of the brake disc.