JPH06249274A - Ventilated disc - Google Patents

Abstract

PURPOSE:To prevent generation of overheat and crack without increasing the weight so much by providing annular projecting parts opposite to each other on the outer circumferential parts of the inner faces of respective discs, inner and outer, and forming the thickness of the outer circumferential part thicker than that of the inner circumferential parts. CONSTITUTION:An inner disc 1 and an outer disc 2 are connected together through many ribs 3 extending in the radial direction, and many vent holes are provided by means of both discs 1, 2 and the ribs 3. The thickness of the outer circumferential parts of both discs 1, 2 is thicker than that of the inner circumferential parts so as to make the thermal capacity of the outer circumferential parts larger than that of the inner circumferential parts. Hereby, mechanical strength is increased and hence fine crack is hardly generated. By rotating the discs, the air in the vent holes is pushed out from outside ports 4b by centrifugal force, the air pressure in the vent holes is reduced, a large quantity of outside new air is sucked into the vent holes from the inner disc side through the inside opening 4a, and both discs 1, 2 are cooled so as to prevent overheat of the discs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved ventilated disc, and more particularly to a ventilated disc having an excellent effect of preventing overheat, which is used in automobiles, industrial vehicles and the like.

[0002]

2. Description of the Related Art A conventional ventilated disc is formed by an inner disc and an outer disc which are formed to have the same inner and outer diameters and have an equal wall thickness. Discs (hereinafter referred to as both discs) are connected by ribs, and a cylindrical bottomed hat portion is connected to the outer disc (for example, Japanese Patent Publication No. 52-89).
No. 52, FIG. 1). When the both discs and the pad frictionally engage with each other during braking, high-temperature frictional heat is generated and the outer peripheral portions of both discs form a high temperature region, while the inner peripheral sides of both discs form a low temperature region. Therefore, thermal stress is generated due to the temperature difference, and fine cracks are generated. Further, the microcracks develop into large cracks extending in the thickness direction and the radial direction of the both disks due to repeated heat generation and cooling, or overheating and rapid cooling, that is, large cracks in the radial direction extending from the outer peripheral end faces of the both disks in the axial direction. However, there is a problem that both disks are destroyed.

Therefore, there is a ventilated disc in which the thickness of the inner disc is increased (for example, Japanese Utility Model Laid-Open No. 57-144634), but the weight of the ventilated disc is effective although the inner disc is prevented from overheating. There is a problem that is increased. Therefore, the present invention has been made in order to solve such a problem, and provides a ventilated disk capable of preventing overheating without increasing the weight so much.

[0004]

The ventilated disc of the present invention is provided with annular protrusions facing the outer peripheral portions of the inner surfaces of the inner disc and the outer disc, and the thicknesses of the outer peripheral portions of the both discs are set to be equal to each other. It is characterized in that it is thicker than the inner peripheral portion of the disc.

[0005]

Since the heat capacities of the outer peripheral portions of the inner disc and the outer disc are increased, the temperature rise of the outer peripheral portions of the both discs is suppressed during frictional engagement between the both discs and the pad, and the both discs are generated during braking. The thermal deformation of can be suppressed.

[0006]

1 and 2 show a ventilated disc according to the present invention, in which an inner disc 1 and an outer disc 2 are connected by a plurality of ribs 3 extending in a radial direction, and the discs 1 and 2 and the ribs are connected to each other. A large number of vent holes 4 are provided by 3 and a bottomed cylindrical hat portion 5 is connected to the outer disk 2. On the outer peripheral portions of the inner surfaces 1a, 2a of the both discs 1, 2, annular protrusions 6 of the same shape are provided so as to face each other, and the thickness of the outer peripheral portions of the both discs 1, 2 is made equal. The thickness of the inner peripheral portion of each of the disks 1 and 2 is made thicker than the inner peripheral portion of
It is formed to have a larger heat capacity than the inner peripheral portion. That is, when the discs 1 and 2 and the pad (not shown) are frictionally engaged with each other to generate frictional heat, the temperature rise of the outer peripheral portions of the discs 1 and 2 is suppressed and overheating is not generated. By making the outer peripheral portions of the discs 1 and 2 thicker than the inner peripheral portions of the discs 1 and 2, the heat dissipation is slightly inferior, but the mechanical strength is increased, so that microcracks are less likely to occur. Become. Further, even if a microcrack occurs, the progress to a large crack is hindered, and it becomes possible to make the progress of the microcrack extremely slower than in the conventional case. In addition, the weight of the brake disc is sufficient for the annular protrusion 6 and the influence on the entire wheel is small, and the volume of the space is not increased.

The outer dimensions of the inner disc 1 and the outer disc 2 are the same, but the inner diameter of the inner disc 1 is larger than the inner diameter of the outer disc 2 so that the outer disc 2 is rotated when the ventilated disc is rotated. The new air is formed so as to easily flow into the ventilation hole 4 from the inner disk 2 side through the inner opening 4a.

When the ventilated disk is rotated in any one direction, the air in the air holes 4 is pushed out by the centrifugal force from the outer openings 4b, the air pressure in the air holes 4 is reduced, and new air outside is generated. A large amount is sucked from the inner disc 1 side through the inner opening 4a into the ventilation hole 4 to cool the both discs 1 and 2.

When the both discs 1 and 2 and the pad (not shown) are frictionally engaged with each other during braking, frictional heat is generated, but the temperature rise of the outer peripheral portions of the both discs 1 and 2 is suppressed, and the overheat is caused. Is prevented. Therefore, it is possible to delay the generation of fine cracks, it is possible to slow the progress rate of the generated fine cracks, it is possible to prevent the generation of large cracks in the radial direction from the outer peripheral end surfaces of the both disks 1, 2 toward the axial direction, The disc will not be damaged and will not scatter during driving.

[0010]

According to the present invention, the annular protrusions are provided so as to face the outer peripheral portions of the inner surfaces of the inner disc and the outer disc, and the outer peripheral portions of the both discs have the same wall thickness. Since it is made thicker than the thickness, it does not affect the space of the disc brake, the influence of the increase in weight on the entire wheel is extremely small, and the disc does not scatter during traveling.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a ventilated disc according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 1 inner disc 1a inner surface 2 outer disc 2a inner surface 6 annular protrusion

Claims (2)

[Claims] 1. Inner discs and outer discs are provided with annular protrusions facing the outer peripheral portions of the respective inner surfaces, and the outer peripheral portions of the both discs are made thicker than the inner peripheral portions of the both discs. Ventilated disc featuring. 2. The ventilated disc according to claim 1, wherein the outer dimensions of the inner disc and the outer disc are the same, and the inner diameter of the inner disc is larger than the inner diameter of the outer disc. Ventilated disc formed.