JPS63308234A - Disc brake rotor - Google Patents

Abstract

PURPOSE:To raise the vibration damping capacity for the mode of vibration being discontinuous so as to prevent a brake noise by manufacturing a rotor with a heterogeneous material unevenly distributed completely at random and not to repeat a similar pattern in the circumferential direction. CONSTITUTION:A rotor unit 1 having a lug 2, with through holes 3 drilled thereon, formed on the inner circumferential edge is connected to the wheel hub through the through holes 3. A brake pad sliding portion 1a is provided on the outer circumference of the rotor unit 1, and brake pad sliding surfaces 4, 5 and a cooling fin 6 are formed on both sides of the rotor unit 1. A border line 9 of an inner circumference material 7 and an outer circumference material 8, which form the rotor unit 1, is formed by using a material heterogeneous in physical quantity of either specific gravity or vibration damping capacity as well as not to repeat a similar pattern in the circumferential direction but in a manner unevenly distributed completely at random. The mode of vibration consequently becomes discontinuous, the vibration damping capacity raised and thus the brake noise prevented without failure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotor for a disc brake.

(Prior Art) A disc brake brakes a rotating body to be braked, such as a rotor that rotates together with the wheels of an automobile, by sandwiching the rotary body between a pair of brake pads. Conventionally, it was common to make them uniformly in the circumferential direction.

For this reason, the conventional disc brake rotor is schematically shown as a disc in FIG.
The illustrated resonance waveform (in the case of the illustrated case, the four-node resonance waveform) is likely to occur,
For example, impulse response characteristic a based on the experimental results shown in Fig. 5
, b, the vibration damping ability was extremely poor. This experimental result was obtained by applying an impulse of 100 g (g is the acceleration of gravity) to a 100 mm diameter point on a 250 mm diameter rotor and measuring the vibration at the same point, and the characteristics a and b were initially ±2. The vibration that was 0dB is still ±0.3dB after 0.1 seconds.
means to hold. The conventional disc brake rotor, which has poor vibration damping ability, sometimes generates an abnormal noise called brake squeal, which significantly reduces its commercial value.

Therefore, as previously described in Japanese Patent Publication No. 62-7408, the applicant of the present application has developed cooling fins that are interposed radially between the sliding surfaces of brake pads, especially in ventilated disc brake rotors, without repeating the same pattern. We proposed a completely random placement technique. According to this technology, as shown by c and d in Figure 5, vibrations that were initially ±2 dB can be suppressed for 0.1 seconds, as is clear from the impulse response characteristics obtained in experiments conducted under the same conditions as conventional rotors. This provides a vibration damping ability that almost dampens the brake noise by a certain amount, and eliminates problems related to brake squeal.

(Problems to be Solved by the Invention) However, this technique can only be applied to the ventilated disc brake rotor with cooling fins, and cannot be applied to a normal disc brake rotor without cooling fins. Moreover, although it is effective against high-frequency vibrations where the number of parts of the resonance waveform e shown in Fig. 4 is the same as the number of cooling fins (usually about 20 to 40 pieces due to the strength of the rotor), the number of parts of the resonance waveform e is It is less effective against 2 to 3 low frequency vibrations.

(Means for Solving the Problems) In view of the above-mentioned problems, the present invention provides a disc brake rotor with
It is made of different materials that are unevenly distributed at random without repeating the same pattern in the circumferential direction.

(Function) The disc brake rotor is pinched between a pair of brake pads to reduce its rotation, and the rotating body to which the rotor is connected can be braked.

Disc brake rotors are made of different materials that are unevenly distributed at random without repeating the same pattern in the circumferential direction, so the vibration mode of the rotor becomes discontinuous, increasing the vibration damping ability and reducing brake shock. Squealing can be reliably prevented.

This measure can be applied to any disc brake rotor with or without cooling fins, and has a wide range of applications.It improves vibration damping ability for any number of resonant waveforms without being restricted by the number of cooling fins. can be fulfilled and has a high degree of freedom.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIGS. 1 and 2 show an example of the measures taken by the present invention for a ventilated disc brake rotor, and numeral 1 indicates the rotor body. This rotor main body 1 has a substantially annular shape, and has projecting ears 2 integrally formed on its inner peripheral edge, and a through hole 3 is bored in each projecting ear.

The rotor body 1 has a bolt (not shown) passed through the through hole 3.
The brake pad is connected to the hub of a wheel, which is a rotating body to be braked, and a brake pad sliding contact portion 1a is set on the outer periphery of the rotor body 1.

The brake pad sliding contact portion 1a has brake pad sliding contact surfaces 4.5 on both sides, on which a pair of brake pads (not shown) are aligned and placed facing each other. These brake pads can brake the rotor body 1 by friction when they pinch the surface 4.5 of the rotor body 1 rotating together with the wheel.

Further, a large number of cooling fins 6 extending radially are interposed between the brake pads 4.5, and the heat generated by the friction is conducted to the fins 6 and then radiated from the fins 6 into the atmosphere, thereby increasing heat radiation efficiency.

In the present invention, the rotor body 1 has an inner peripheral material 7 and an outer peripheral material 8.
These inner and outer peripheral materials are unevenly distributed at random without repeating the same pattern in the circumferential direction, as shown by the boundary line 9. The inner and outer circumferential materials 7.8 are made of different materials having different physical quantities such as specific gravity and damping capacity. For example, the inner circumferential material 7 is made of cast iron FC25 having a tensile strength of about 25 kg and a small vibration damping ability, and the outer circumferential material 8 is cast iron FCIO with a tensile strength of about 10 kg and a large vibration damping ability.

In manufacturing such a rotor body 1, melted FCIO is poured into a mold to form the outer peripheral material 8, and before this completely solidifies, melted Fe12 is poured into the mold to form the inner peripheral material 8.
Nasu. As a result, a portion of the previous FCIO melts out into the Fe 12, and the inner and outer circumferential materials 7.8 made of different materials are unevenly distributed at random without repeating the same pattern in the circumferential direction.

At this time, if you want to control the uneven distribution pattern without leaving it to chance, you can do this by using a cooling mold and adjusting the solidification rate so that the desired uneven distribution pattern can be obtained.

Further, if the rotor body 1 manufactured as described above has a large rotational imbalance, it is preferable to attach a mass body such as a balancer to maintain the balance.

Note that the above idea of the present invention is based on the third
Needless to say, the present invention can be similarly applied to a normal disc brake rotor as shown in the figure.

(Effects of the Invention) As described above, since the disc brake rotor of the present invention is made of different materials 7.8 in which members are randomly formed without repeating the same pattern in the circumferential direction, the vibration mode becomes discontinuous and the vibration Brake squeal can be reliably prevented by increasing the damping capacity as shown in c and d in FIG. 5, for example.

Moreover, this measure can be applied to all disc brakes with or without cooling fins 6, and has a wide range of applications.The uneven distribution of the material 6.7 can also improve the vibration damping ability for both low-frequency vibrations and high-frequency vibrations. can.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the disc brake rotor of the present invention, Fig. 2 is a sectional view of [-1T] of Fig. 1, and Fig. 3 is a similar to Fig. 2 showing another example of the present invention. 4 is a schematic diagram showing a four-node equally divided resonant waveform generated in a conventional disc brake rotor. Figure 5 is a comparison of the impulse response characteristics of the disc brake rotor according to the present invention and the conventional case. FIG. 1... Rotor body 2... Pronged ears 4.5...
Brake band sliding surface 6... Cooling fin 7... Inner circumferential material 8... Outer circumferential material 9... Boundary line Patent applicant Nissan Motor Co., Ltd. Figure 1 ■ Figure 2 Figure 4

Claims (1)

[Claims] 1. A disc brake characterized in that the disc brake rotor, whose rotation is braked by being squeezed between a pair of brake pads, is made of different materials that are unevenly distributed at random without repeating the same pattern in the circumferential direction. Rotor.