JPH03117731A - Disc plate - Google Patents

Abstract

PURPOSE:To prevent allophone occurrence at the time of braking by making outer and inner plates have a mutually different construction material, and making the construction material of the inner plate have the Young's modulus larger than that of the construction material of the outer plate. CONSTITUTION:Inner and outer plates 4 and 3 composing a ventilation disc 2 consist of ductile iron and a gray casting iron respectively. Since ductile iron has the Young's modulus larger than that of the gray casting iron, the vibrations of the inner and outer plates 4 and 3 are acted so as to be mutually canceled. Consequently since a vibration level in each resonance frequency of the inner and outer plates 4 and 3 can be reduced moreover to act as an effective dynamic damper, the vibration level can be considerably diminished. As a result, the occurrence of allophone of a disc brake 1 at the time of braking can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a disc plate, and more specifically to a ventilated disc that can prevent abnormal brake noise during braking. It's about plates.

[Prior art]

As a structure of the disc plate in a disc brake, a ventilated disc plate, that is, a ventilation disc, which has excellent cooling performance and can effectively prevent heat fade, is known (for example, the Ventilation Disk). -51224 etc.).

Such ventilation discs generally include an outer plate that is integrally fixed to the hub of the wheel, and an inner plate that is supported by the outer plate at a predetermined interval, and each side surface of the outer plate and the inner plate. By frictionally engaging with a pair of pads supported by the caliper, it brakes the wheels of the vehicle that are integrally connected to the outer plate, and during braking, air flows through the gap formed between both plates. flow, thereby cooling the disc plate and effectively avoiding heat fade phenomena in disc brakes.

[Problem to be solved by the invention]

However, in such a ventilation disc, the outer plate and the inner plate have different shapes from each other due to their structural constraints or design constraints such as the layout or weight of the disc brake. The masses of both plates are different from each other, and since both the inner plate and the outer plate are made of the same material, for example, gray cast iron, the inner plate and the outer plate are different from each other. It had a natural frequency. Therefore, the inner plate and the outer plate of the conventional ventilation disc have different resonance frequencies, and as shown in FIGS. 3A and 3B, for example, the vibration characteristics of the inner plate and the outer plate are as follows.
Each resonance frequency is about 6.7KHz and about 8.0KH
Each existed near z.

In such disc brakes, when the resonant frequency of the pad that frictionally engages with the ventilation disc is near the resonant frequency of the inner plate or outer plate, an abnormality called a so-called chi sound occurs. There is a problem in that sound, that is, brake noise in a frequency range of approximately 4 kHz or higher, is likely to occur.

The present invention has been made in view of the above points, and its object is to provide an outer plate connected to a wheel, and an outer plate supported by the outer plate and spaced apart from the outer plate by a predetermined distance. In a disc brake disc plate equipped with a connected inner plate, it is possible to eliminate brake noises during braking, especially abnormal noises called so-called chi noises, without changing the shape of the inner or outer plate. An object of the present invention is to provide a disk plate that can effectively prevent the occurrence of such occurrence.

[Means to solve the problem]

In order to achieve the above object, the present invention provides that in the disk plate, the outer plate and the inner plate are made of different materials, and the material of the inner plate has a Young's modulus greater than that of the material of the outer plate. To provide a disc plate characterized by having a high ratio.

In a preferred embodiment of the present invention, the materials forming the inner plate and the outer plate respectively have a mass of MI
M2, inner plate 3 and outer plate 4
The materials are selected from materials having a Young's modulus that substantially satisfies the following relational expression, where the spring constants are + and Kx, respectively.

[Effect]

According to the disk plate having the above configuration, the inner plate is formed from a material having a larger Young's modulus than the outer plate, so the natural frequency of the inner plate can be adjusted without changing the shape of the inner plate or the outer plate. It is possible to approach the natural frequency of the outer plate, thereby causing the vibration of the inner plate and the vibration of the outer plate to cancel each other out, reducing the vibration level at each resonance frequency of the inch plate and outer plate. becomes possible.

In this way, since vibrations near the resonance frequency in the inch plate and the outer plate can be reduced, disc brakes equipped with the above-mentioned disc plate can reduce the occurrence of abnormal brake noise, especially whistling noise, during braking. is effectively prevented.

Further, in the above preferred embodiment, the resonance frequencies of the inner plate and the outer plate substantially match,
Since the inner plate acts as a favorable dynamic damper for the outer plate, the vibration level of the inner plate and the outer plate is greatly reduced.
In this way, the occurrence of the above-mentioned abnormal noise in the disc brake is effectively prevented.

[Embodiments] Hereinafter, embodiments of the disk plate according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic vertical cross-sectional view showing a disc brake for a vehicle equipped with a disc plate according to this embodiment, and FIG. 2 is a diagram showing the vibration characteristics of the outer plate shown in FIG. 1.

As shown in FIG. 1, the disc brake 1 includes a ventilation disc 2 that rotates integrally with a vehicle wheel (not shown), and a ventilation disc 20 on both sides of the ventilation disc 2 in the vehicle width direction. It is generally composed of a pair of pads 6.6 arranged to face each other, and a caliper 7 supporting these pads 6.6.

The ventilation disc 2 includes a substantially annular inner plate 4, an outer plate 3 arranged at a slight interval on the side of the inner plate 4 in the vehicle width direction, and a space between the inner plate 4 and the outer plate 3. Intervened in
Consisting of a plurality of ribs 11 that integrally connect the inner plate 4 and the outer plate 3, the inner plate 3
The structure is such that both plates 3 and 4 are effectively cooled by ventilation in the gap formed between the outer plate 4 and the outer plate 4 .

The outer plate 4 is generally formed in a generally annular shape, and a radially inner peripheral portion thereof extends outward in the vehicle width direction.
It is fixed to a hub 8 (indicated by phantom lines) by a plurality of bolts 9, and the hub 8 supports a wheel (not shown) on its outer side in the vehicle width direction, and also supports a wheel (not shown) via a pair of bearings 10.10. Knuckle spindle 1
1 for relative rotation.

The caliper 7 also includes a hydraulically actuated cylinder (not shown) connected to the hydraulic circuit of the brake, and by operating this cylinder, each pad 6.6 is attached to the ventilation disc 2. The pad 6.6 is configured to press against both side surfaces in the vehicle width direction, that is, the side surfaces of the inch plate 3 and the outer plate 4, and brake the wheel by sandwiching the inner plate 3 and the outer plate 4 with the pads 6.6. There is.

In this embodiment, the outer plate 4 is made of gray cast iron, which is conventionally used to form each plate of a ventilation disk. Therefore, the vibration characteristics of the outer plate 4 itself are as shown in FIG. 3A. In this case, the resonant frequency exists around 8.0 KHz.

On the other hand, the inner plate 3 is made of ductile cast iron,
This ductile cast iron has a Young's modulus larger than that of the gray cast iron forming the outer plate 4, and the masses of the inner plate 3 and the outer plate 4 are ? v
L M2, inner plate 3 and outer plate 4
It has a Young's modulus that can substantially satisfy the following relational expression when the spring constants of are respectively set as , K2.

In the ventilation disc 2 configured in this way, the natural frequency of the inner plate 3 is modified to a higher frequency side, so that it becomes close to the natural frequency of the outer plate 4. Moreover, the natural frequency of the inner plate 3 made of ductile cast iron having a Young's modulus that substantially satisfies the above formula (2) substantially matches the natural frequency of the outer plate 4, and the natural frequency of the inner plate 3 and outer plate 4 is Since both resonant frequencies exist in the frequency range around 8.0 KHz, the inner plate 3 acts as an effective dynamic damper for the outer plate 4.

Therefore, the vibration of the inch plate 3 and the vibration of the outer plate 4 during braking work to cancel each other out, and the resonance frequency of the inner plate 3 and the outer plate 4, that is, approximately 8.0 Kf (in the frequency region near z) The vibration level is greatly reduced.Thus, in the disc brake 1, brake noise during braking,
In particular, the generation of chi sounds is very effectively prevented.

Thus, in this embodiment, the inner plate 3 and the outer plate 4 that constitute the ventilation disc 2 are made of ductile cast iron and gray cast iron, respectively, and the ductile cast iron has a larger Young's modulus than the gray cast iron. Therefore, the vibrations of the inner plate 3 and the vibrations of the outer plate 4 act to cancel each other out, and the vibrations of the inner plate 3 and the outer plate 4 act to cancel each other out.
The vibration level at each resonant frequency of Since it acts as a dynamic damper, the vibration level in the inch plate 3 and the outer plate 4 is greatly reduced.
Thus, the abnormal noise of the disc brake 1 during braking,
In particular, the generation of chi sounds is very effectively prevented.

The present invention is not limited to the above-mentioned embodiments, and various changes and modifications can be made within the scope of the invention described in the claims, and these are also included within the scope of the present invention. Needless to say, it is.

For example, in the above embodiment, the outer plate and the inner plate are made of gray cast iron and ductile cast iron, respectively. It is also possible to form each from cast iron.

〔Effect of the invention〕

According to the present invention, an outer plate connected to a wheel;
In a disc brake disc plate that includes an inner plate supported by the outer plate and connected to the outer plate at a predetermined distance, the brake during braking can be improved without changing the inch or the shape of the outer plate. It becomes possible to provide a disk plate that can effectively prevent the occurrence of abnormal noises, particularly so-called chi noises.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view showing a disc brake equipped with a disc plate according to an embodiment of the present invention. FIG. 2 is a diagram showing the vibration characteristics of the outer plate shown in FIG. 1. FIGS. 3A and 3B are diagrams showing vibration characteristics of an inch plate and an outer plate that constitute a conventional disk plate. 1... Disc brake, 2... Ventilation disc, 3... Outer plate, 4... Inner plate, 5... Rib, 6... Pad, 7... ...Caliper, 8..Hub, 9..Bolt, 10..Bearing, 11..Knuckle spindle. Figure 1

Claims (1)

[Claims] A disc plate for a disc brake comprising an outer plate connected to a wheel, and an inner plate supported by the outer plate and connected to the outer plate at a predetermined distance, the outer plate and the inner plate. and are made of different materials, and the material of the inner plate has a Young's modulus greater than the Young's modulus of the material of the outer plate.