Brakes – Elements – Brake wheels
Reexamination Certificate
1997-07-16
2001-04-17
Graham, Matthew C. (Department: 3613)
Brakes
Elements
Brake wheels
C188S073200
Reexamination Certificate
active
06216827
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a disc rotor for a disc brake and, more particularly, to a disc rotor suitable for a disc brake apparatus for a vehicle.
2. Description of the Related Art
Japanese Laid-Open Utility Model Application No. 59-63238 discloses a disc brake apparatus. The disc brake apparatus disclosed in this patent document comprises a disc rotor rotating with a wheel, a pair of brake pads provided on opposite sides of the rotor, and a caliper supporting the brake pads. The disc rotor includes a hat portion which is fixed to an axle hub connected to a vehicle body via a bearing. Additionally, the disc rotor includes an annular sliding portion on the outer circumference of the hat portion. When a depression force is applied to a brake pedal, the caliper moves the brake pads toward the disc rotor in response to the depression force. As a result, the brake pads are pressed against a slide portion of the disc rotor in response to the depression force.
When the brake pads are pressed against the rotor, a frictional force is generated between the disc rotor and the brake pads. The frictional force acts as a force to restrict the rotation of the disc rotor, that is, a brake force for restricting the rotation of the wheel. Thus, the disc brake apparatus generates the brake force in response to the depression force applied to the brake pedal.
When a brake force is generated by the brake pads being pressed against the disc rotor, vibration is generated in the disc brake due to the sliding of the brake pads on the disc rotor. In such a case, a compressional wave which transmits in a circumferential direction in an annular sliding portion of the disc rotor is generated. Hereinafter, this vibration is referred to as in-plane vibration. Additionally, axial direction vibration is also generated which periodically displaces each portion of the disc rotor in the axial direction. When the frequency of the vibrations matches the natural frequency of the brake system, a so-called brake noise is generated.
If the vibration generated in the disc rotor can be efficiently attenuated, a disc brake having less brake noise can be achieved. Since the in-plane vibration of the disc rotor transmits to the sliding plane of the disc rotor, the in-plane vibration hardly transmits to the caliper. On the other hand, the axial direction vibration is easily transmitted to the caliper since the direction of transmission of the axial direction vibration matches the direction of movement of the caliper.
The vibration generated in the rotor is further attenuated as the vibration is transmitted to a heavier material such as the caliper. Accordingly, as far as reduction of the brake noise is concerned, it is preferred that the vibration, which is generated in the rotor due to the brake pads being pressed against the disc rotor, has a large component in the axial direction. However, in the conventional disc rotor, no measures have been taken to generate the vibration having a large component in the axial direction.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful disc rotor of a disc brake in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a disc rotor used in a disc brake which generates vibration having a large component in the axial direction of the disc rotor when a brake pad is pressed against the disc rotor.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a disc rotor of a disc brake for a vehicle, comprising:
a hat portion adapted to be fixed to an axle hub of the vehicle;
a sliding portion adapted to be pressed by a brake pad so as to generate a brake force;
a connecting portion connecting the sliding portion to the hat portion; and
a plurality of ribs for increasing rigidity of the connecting portion.
According to the above-mentioned invention, since the ribs are provided to the connecting portion so as to increase the rigidity of the connecting portion between the sliding portion and the hat portion, the vibration generated in the disc rotor due to the brake pad being pressed against the sliding portion has a large component in the direction of the rotational axis of the disc rotor. Accordingly, the vibration generated in the disc rotor tends to be transmitted to a caliper pressing the brake pad onto the disc rotor. This substantially increases a mass of the brake system and, thus, the generation of a brake noise is suppressed.
In one embodiment of the present invention, the ribs may be provided to the connecting portion. Additionally, each of the ribs may extend in a radial direction of the disc rotor. Further, each of the ribs may be integral with a fin provided in the disc rotor, the fin extending in a radial direction of the disc rotor.
Additionally, a height of each of the ribs may be decreased toward an inner side of the disc rotor, the height measured in a direction of a rotational axis of the disc rotor.
In one embodiment according to the present invention, the ribs may be provided to an outer surface of the hat portion so that an end of each of the ribs is connected to the connecting portion. Additionally, the ribs may be integral with the hat portion and the connecting portion. Further, each of the ribs may extend in a direction of a rotational axis of the disc rotor. Further, a height of each of the ribs may be increased toward the connecting portion, the height measured in a radial direction of the disc rotor.
In one embodiment according to the present invention, each of the ribs may include a first portion provided to the connecting portion and a second portion provided to an inner surface of the hat portion, the first portion extending in a radial direction of the disc rotor, the second portion extending in a direction of a rotational axis of the disc rotor, the first portion and the second portion being integral with each other.
Additionally, there is provided according to another aspect of the present invention a disc rotor of a disc brake for a vehicle, comprising:
a hat portion adapted to be fixed to an axle hub of a vehicle;
a sliding portion adapted to be pressed by a brake pad so as to generate a brake force;
a connecting portion connecting the sliding portion to the hat portion; and
a low-rigidity portion provided along a substantial boundary between the sliding portion and the connecting portion, the low-rigidity portion having a rigidity lower than a rigidity of each of the sliding portion and the connecting portion.
According to the above-mentioned invention, the low-rigidity portion is provided between the sliding portion and the connecting portion. The low-rigidity portion is more flexible than the sliding portion and the connecting portion. Accordingly, when the brake pad is pressed against the sliding portion, the axial direction vibration is generated in the disc rotor which vibration has an antinode or loop of vibration formed at the low-rigidity portion. This results in the vibration having a large component in the direction of the rotational axis of the disc rotor. Accordingly, the vibration generated in the disc rotor tends to be transmitted to a caliper pressing the brake pad onto the disc rotor. This substantially increases a mass of the brake system and, thus, the generation of a brake noise is suppressed.
In one embodiment of the present invention, the low-rigidity portion may be formed by an annular groove formed along the substantial boundary between the sliding portion and the connecting portion.
The low-rigidity portion may be formed by a first annular groove and a second annular groove, the first annular groove being formed on one side of the disc rotor and the second annular groove being formed on the other side of the disc rotor so that the low-rigidity portion is formed between the first annular groove and the second annular groove.
Additionally, the disc rotor according to the present invention may further com
Hayakawa Yasushi
Ichiba Yasuaki
Tanabe Naoki
Graham Matthew C.
Oliff & Berridg,e PLC
Toyota Jidosha & Kabushiki Kaisha
Williams Thomas J.
LandOfFree
Disc brake rotor which generates vibration having a large... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disc brake rotor which generates vibration having a large..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disc brake rotor which generates vibration having a large... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2455857