JP2000329174A - Brake disc for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake disc for a vehicle prevented from the generation of deviation and warping. SOLUTION: The inner peripheral part of a brake disc 1 is provided with first connecting bars 12 and second connecting bars 13. The first connecting bars 12 are formed in strip shape extending gradually to one side in a circumferential direction toward the outside in a radial direction and lined up in large numbers. The second connecting bars 13 are formed to arrange crests and troughs alternately in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced air-cooled vehicle brake disk having a heat-dissipating air passage formed in an outer peripheral portion on which a braking force acts.

[0002]

2. Description of the Related Art Conventionally, a brake disk for a vehicle of a forced air cooling type, a so-called ventilated brake disk,
A large number of heat-dissipating air passages are formed in the outer peripheral portion where the brake pad slides. As this kind of brake disc,
For example, there is one disclosed in Japanese Patent No. 2835727.

[0003] The brake disc disclosed in this publication is
An inner peripheral portion fixed to the wheel side and an outer peripheral portion on which a brake pad slides and a braking force is applied are integrally formed by casting, and a heat dissipation air passage is formed in the outer peripheral portion in a casting process. If the required minimum rigidity is ensured, the thickness of the brake disk formed by casting becomes large, and the weight becomes heavy.

[0004] A conventional brake disk which can be reduced in weight while adopting a structure in which a heat-dissipating air passage is formed in the outer peripheral portion is formed by forming a large number of radial fins on the outer peripheral portion, and forming these fins on both front and back surfaces. In which a ring-shaped friction plate is fixed. The friction plate is formed in an annular shape with a material having high wear resistance and brazed to the fin.

The fins are inclined so as to extend rearward in the rotational direction toward the outside in the radial direction, so as to have a function of a centrifugal fan. In other words, a structure is adopted in which a radiating air passage is formed between the fins and between the friction plates.

[0006]

However, as described above, in any of the brake disk in which the air passage for heat radiation is formed by casting and the brake disk in which the friction plate is fixed to form the air passage, the brake pad and If the temperature of the outer peripheral portion rises significantly due to the friction of the disk, there is a problem that the entire disk warps or the outer peripheral portion oscillates.

This is considered to be due to the fact that the direction of thermal expansion is regulated by the inner peripheral portion when the outer peripheral portion thermally expands. That is, the outer peripheral portion thermally expands so that the outer diameter of the disk increases, but the rigidity of the inner peripheral portion hinders the thermal expansion, so that a thermal stress is generated in the outer peripheral portion. This is because the lower part is deformed.

Further, in a brake disk having a radiating air passage formed by a fin and a friction plate, if the brake disk is frequently used at a high temperature, the brazed portion may be damaged by the above-mentioned thermal stress. This is because the thermal stress generated due to the difference between the amount of thermal deformation of the fin and the amount of thermal deformation of the friction plate is concentrated on the brazing material joined to a portion where a sharp corner is formed. The portion where the sharp angle is formed is a portion where the side edge of the outer peripheral fin and the inner edge of the friction plate obliquely intersect with each other when the brake disk is viewed from the axial direction.

For this reason, in a brake disk in which a radiating air passage is formed by fins and friction plates, it is required to improve reliability by preventing a brazed portion from being damaged by thermal stress.

The present invention has been made to solve such a problem, and a first object of the present invention is to provide a brake disk for a vehicle which does not cause runout or warpage.
A second object of the present invention is to provide a highly reliable brake disk for a vehicle in which a cooling air passage is formed by fins and friction plates to reduce the weight and without damaging a brazed portion. .

[0011]

In order to achieve this object, a vehicle brake disk according to the present invention is arranged such that the outer circumferential side of a wheel connecting portion in an inner circumferential portion is gradually formed in a circumferential direction toward a radially outer side. A strip-shaped first extending to one side
Of the first connecting bar, and a second band-like connecting bar connected to one end of the first connecting bar.
A large number of the connecting bars are arranged in parallel at intervals in the circumferential direction, and the second connecting bars are formed so that peaks and valleys are alternately arranged in the circumferential direction.

According to the present invention, the first connecting bar is elastically deformed mainly in the surface direction by the radial expansion of the outer peripheral portion, and the second connecting bar is mainly deformed by the circumferential expansion of the outer peripheral portion. The connecting bar is elastically deformed.

According to a second aspect of the present invention, there is provided a brake disk for a vehicle according to the first aspect of the present invention, wherein the first connecting bar is provided on the inner peripheral side and the second connecting bar is provided on the inner peripheral side. A plurality of narrow fins radially extending radially outward from the tops of the peaks and valleys of the second connection bar; and The fin is formed from an annular friction plate made of a material having high wear resistance and joined to both the front and back surfaces of the fin.

According to the present invention, no sharp angle is formed at the intersection between the side edge of the fin and the inner peripheral edge of the friction plate when viewed from the axial direction of the brake disk. It is possible to prevent the thermal stress generated due to the difference in the amount of thermal deformation of the plate from being concentrated on the joining material at the connection portion.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle brake disk according to the present invention will be described below in detail with reference to FIGS. 1 is a front view of a vehicle brake disk according to the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a front view for explaining first and second connecting bars.

In these figures, what is denoted by reference numeral 1 is
4 is a brake disc according to the embodiment. The brake disk 1 is mounted on a power unit of a snowmobile (not shown), and runs at a high speed (8000 rpm).
８8500 rpm) and fixed to a rotating shaft (not shown).

The brake disk 1 comprises a boss 2 fixed to the rotating shaft, a disk body 4 fixed to the boss 2 with rivets 3, and a friction plate 5 brazed to the disk body 4. . A brake pad (not shown) comes into sliding contact with the friction plate 5.

As shown in FIG. 2, the boss 2 integrally forms a cylindrical body 6 for shaft penetration and a flange 7 for mounting a disk body by forging. The cylindrical body 6 has a structure in which the cylindrical body 6 is fixed by a key (not shown) so as not to rotate on the rotating shaft. The keyway is indicated by reference numeral 6a. The flange 7 is formed in a circular shape in a front view as shown in FIG. 1, and as shown in FIG. 2, through holes 7a (see FIG. 2) through which the rivets 3 are inserted are formed at six places.

The disk body 4 is formed in an annular plate shape from high-tensile steel, and has an inner annular portion 11 fixed to the boss 2 and a radially outward portion extending from the inner annular portion 11. A first connecting bar 12 extending in the form of a narrow band, a second connecting bar 13 in the form of a narrow band connected to an extended end of the first connecting bar 12, and a connection to the second connecting bar 13; And radially extending fins 14 are integrally formed.

The inner peripheral annular portion 11, the first connecting bar 12 and the second connecting bar 13 constitute an inner peripheral portion of the brake disc 1 according to the present invention, and the fins 14 are provided.
The friction plate 5 constitutes the outer peripheral portion of the brake disc 1 according to the present invention.

As shown in FIG. 2, the inner peripheral side annular portion 11 is provided with six through holes 11a through which the rivets 3 are inserted. I have. The inner peripheral side annular portion 11 constitutes a wheel connecting portion according to the present invention.

The rivet 3 is of a press caulking type, and has a through hole 7a of the flange 7 and an inner peripheral annular portion 11
To the hole wall surface of the through hole 11a. By adopting this structure, when the braking force is transmitted from the disk main body 4 to the boss 2, the braking force can be distributed almost equally to all the rivets 3.

As shown in FIG. 3, the first connecting bar 12 is gradually shifted in the circumferential direction from the inner circumferential annular portion 11 toward the outside in the radial direction, as indicated by hatching to the lower right. And a plurality of them are arranged side by side at intervals in the circumferential direction.

The second connecting bar 12 is formed so that peaks and valleys are alternately arranged in the circumferential direction, as indicated by hatching in the lower left direction in FIG. In this embodiment, one end of the first connection bar 12 is connected to the top of the valley.

The fins 14 are formed in a narrow band by radially forming grooves on the outer peripheral edge of the disk body 4.
The second connection bar 13 extends linearly from the top of the peaks and valleys radially outward along the radial direction.

The friction plate 5 is formed in a ring shape from a material having high wear resistance, and is joined to the front and back surfaces of the fin 14 by brazing. By joining the friction plates 5 to the fins 14 in this manner, a radiating air passage 15 is formed between the fins 14 and between the friction plates 5 on both sides.

That is, when the brake disc 1 rotates, air flows from the space S formed between the base ends of the fins 14 and radially inside the inner peripheral edge of the friction plate 5 into the air passage 15. The air flows radially outward in the air passage 15 and is discharged outward from the outer peripheral edge of the brake disc 1. By the air flowing through the air passage 15, the outer peripheral portion of the brake disk 1 where the temperature rises most is cooled.

According to the vehicle brake disk 1 configured as described above, the temperature of the outer peripheral portion increases due to frictional heat due to the frictional contact of the brake pad with the friction plate 5. The outer peripheral portion is cooled by the air flowing through the heat-dissipating air passage 15. However, if the braking state continues for a long time,
When braking is frequently performed, the temperature of the outer peripheral portion further rises despite being cooled by heat radiation.

When the temperature rises, the outer peripheral portion of the brake disk 1 thermally expands so that its diameter increases. That is,
The outer peripheral portion extends in both the radial direction and the circumferential direction. When the outer peripheral portion expands in this way, the fins 14 constituting a part of the outer peripheral portion are formed integrally with the inner peripheral portion of the brake disc 1, so that the outer peripheral portion defines the inner peripheral portion in the radial direction and the circumferential direction. Thermal stress is generated.

When the inner peripheral portion is pulled in the radial direction, the first connection bar 12 is mainly elastically deformed such that the extending direction approaches the radial direction with the inner peripheral end as the base end. That is, the first
Is elastically deformed as shown by a two-dot chain line A in FIG. Further, when the inner peripheral portion is pulled in the circumferential direction, the second connection bar 13 is mainly elastically deformed so that the undulations of the peaks and valleys become gentle.

Therefore, this brake disc 1
The first connecting bar 12 is elastically deformed to allow the outer peripheral portion to expand mainly in the radial direction, and the second connecting bar 13 is elastically deformed to mainly expand the outer peripheral portion in the circumferential direction. Is allowed, the outer peripheral portion is easily deformed in the direction (radial direction) along the main surface of the brake disk 1, and run-out and warpage hardly occur.

Further, since the fins 14 are formed so as to extend linearly in the radial direction, the fins 1 are viewed from the axial direction as shown in FIG.
A sharp angle is no longer formed at the connection portion where the side edge of 4 and the inner peripheral edge of the friction plate 5 intersect. As a result, it is possible to prevent the thermal stress generated due to the difference in the amount of thermal deformation between the fin 14 and the friction plate 5 from being concentrated on the brazing material at the connection portion.

Therefore, it is possible to prevent the brazing material at the connection portion from being damaged by thermal stress.

In this embodiment, the first connecting bar 12 is arranged on the inner peripheral side and the second connecting bar 1
Although the example in which 3 is disposed on the outer peripheral side has been shown, the radial positions of both connecting bars 12 and 13 can be appropriately changed. That is, the second connection bar 13 can be disposed on the inner peripheral side, and the first connection bar 12 can be disposed on the outer peripheral side.

Further, the first inner peripheral portion of the brake disc 1
If the connecting bar 12 and the second connecting bar 13 are provided, the outer peripheral portion can adopt a structure not using the friction plate 5. That is, the inner peripheral portion having both the connection bars 12 and 13 and the outer peripheral portion having the heat radiation air passage may be integrally formed by casting.

Further, in this embodiment, the form adopted when the present invention is applied to a brake disk for a snowmobile is shown. However, in addition to a snowmobile, motorcycles, three-wheeled vehicles, four-wheeled vehicles, and other vehicles are also used. Can be applied.

[0037]

As described above, according to the present invention, the first connecting bar is elastically deformed mainly in the surface direction by the radial expansion of the outer peripheral portion, and the outer peripheral portion is expanded in the circumferential direction. Thereby, the second connection bar is mainly elastically deformed. Therefore, the outer peripheral portion is easily deformed in the direction along the main surface of the brake disk, and thus a brake disk free from runout and warpage can be provided.

According to the second aspect of the present invention, since air flows during rotation in the air passage formed between the fins, a forced air cooling system in which a heat radiation air passage is formed by combining a plurality of members. Brake disc can be manufactured. This brake disc can be formed thinner than when the air passage is formed by casting, and the weight can be reduced. The cost does not increase significantly.

Further, since there is no sharp angle formed at the connecting portion where the side edge of the fin and the inner peripheral edge of the friction plate intersect when viewed from the axial direction of the brake disk, the heat of the fin and the friction plate is not increased. It is possible to prevent the thermal stress generated due to the difference in the amount of deformation from being concentrated on the joining material at the connection portion.

Therefore, it is possible to prevent the joining material of the connecting portion from being damaged by the thermal stress.
A highly reliable vehicle brake disk can be provided while adopting a structure that can be formed thin to reduce the weight.

[Brief description of the drawings]

FIG. 1 is a front view of a vehicle brake disc according to the present invention.

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

FIG. 3 is a front view for explaining first and second connection bars.

[Explanation of symbols]

1. Brake disc, 2. Boss, 4. Disc body,
5: friction plate, 11: inner annular portion, 12: first connection bar, 13: second connection bar, 14: fin, 15 ...
Air passage for heat dissipation.

Claims (2)

[Claims] In a brake disc integrally formed with an inner peripheral portion fixed to a wheel side and an outer peripheral portion on which a braking force acts, an outer peripheral side of a wheel connecting portion of the inner peripheral portion is
A first strip-shaped connecting bar extending gradually toward one side in the circumferential direction toward the outside in the radial direction, and a second strip-shaped connecting bar connected to the extended end of the first linking bar. And a large number of the first connection bars are arranged side by side at intervals in the circumferential direction, and the second connection bar is
A brake disc for a vehicle, wherein peaks and valleys are alternately arranged in a circumferential direction. 2. The vehicle brake disc according to claim 1, wherein a first connecting bar is provided on an inner peripheral side, and a second connecting bar is provided on an outer peripheral side. Numerous narrow fins radially extending radially outward from the tops of the peaks and valleys of the second connecting bar, and an annular ring made of a highly wear-resistant material joined to the front and back surfaces of the fins A brake disc for a vehicle, wherein the brake disc is formed from a friction plate.