JP2003314601A - Rotor for brake device and combination of rotor with wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor for a brake device capable of efficiently feeding to a wheel 12 the thermal energy of a ventilated type disc 7 with its temperature raised with the friction at the time of braking, thereby suppressing a temperature rise of the disc 7, and securing a stable braking force and also prolonging the lifetime of pads 5. <P>SOLUTION: The ventilated type disc 7 has a mounting part 9 whose one surface serves as a mounting surface 20 to be butted with the wheel 12, and a coating film 21 consisting of a metal having a good thermal conductivity is provided on the mounting surface 20. This improves the flow of the thermal energy from the disc 7 to the wheel 12. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating body for a braking device such as a braking disc or a braking drum, which is used in a state of being incorporated in a disc brake or a drum brake which is a braking device for an automobile, and the braking. The present invention relates to improvement of a combination of a rotating body for an apparatus and a wheel.

[0002]

2. Description of the Related Art Disc brakes have been widely used as a braking device for braking an automobile.
FIG. 10 shows a disc brake described in JIS D 0107. A piston 4 is oil-tightly fitted to a cylinder 3 provided in a cylinder body 2 which is supported by a suspension device so as to sandwich a disk 1 rotating with a wheel. At the time of braking, pressure oil is fed into the cylinder 3, and a pair of pads 5 and 5 provided on both sides of the disc 1 are pressed against both side faces of the disc 1.

As the disc 1 constituting such a disc brake, JIS D 0107 describes a solid disc 6 as shown in FIG. 11 and a ventilated disc 7 as shown in FIG. Both the solid disk 6 and the ventilated disk 7 are made of metal and are formed into a disk shape as a whole, and a half portion near the outer diameter is a friction plate portion 8 for pressing the pads 5 and 5 (FIG. 10). The portion closer to the inner diameter than the friction plate portion 8 is the mounting portion 9. The mounting portion 9 is provided in a state of being offset to the friction plate portion 8 in the axial direction. The solid disk 6 and the ventilated disk 7 are attached to the mounting flange 11 of the hub unit 10 for supporting wheels by the mounting portion 9.
(See FIG. 1, which shows an embodiment of the present invention).

The solid disk 6 and the ventilated disk 7 as described above are generally made of cast iron. On the other hand, by reducing the so-called unsprung load,
It has been conventionally considered that the solid disk or the ventilated type disk is made of a light alloy such as an aluminum alloy in order to improve running performance centering on ride comfort and running stability. For example, Japanese Patent Laid-Open No. 2000-3176
Japanese Patent Publication No. 09 describes a technique for producing a ventilated disk from a light alloy matrix composite material {MMC (metal matrix composite)} such as an aluminum alloy.

[0005]

Even when the brakes are heavily used when traveling on a mountain road, for example, the load of the friction material (lining) forming the pads 5 and 5 is reduced to obtain a stable braking force. In order to extend the life of the friction material, it is preferable to suppress the temperature rise of the disc 1. This point is the same regardless of whether the disk 1 is the solid disk 6 or the ventilated disk 7. However, the conventional disk 1 still has room for improvement in terms of suppressing the temperature rise. This point will be described below.

During braking, the disc 1 has pads 5, 5
While the temperature rises based on the friction with, the temperature rise can be suppressed by the heat dissipation into the air. The ventilated disk 7 is more advantageous than the solid disk 6 in terms of effective heat dissipation. However, in order to further suppress the temperature rise during braking, it is advantageous to consider the use of the wheel 12 (see FIG. 1 showing the embodiment of the present invention) that is fixedly coupled to the disc 1. That is, since the wheel 12 is larger than the disc 1 and has a much larger heat capacity, if the heat energy generated during braking is transferred from the disc 1 to the wheel 12, the temperature rise of the disc 1 can be suppressed to a low level. To be Moreover, since the wheel 12 has a large surface area, it is advantageous from the viewpoint of efficiently dissipating heat into the air.

However, in the case of the conventional disk 1,
It was not always possible to efficiently transfer the heat energy from the disc 1 to the wheel 12. Therefore, from the viewpoint of suppressing the temperature rise of the disk 1 during braking, the existence of the wheel 12 cannot always be effectively utilized. The reason for this is that this wheel 12 and the above-mentioned disc 1
This is because no particular consideration is given to the improvement of the heat dissipation from the disk 1 to the wheel 12 side when there is a minute air layer existing between and. Further, although the mounting surfaces (surfaces facing each other) of the disk 1 and the wheel 12 are flat surfaces, the mounting surface is entirely covered by the unavoidable manufacturing error or minute elastic deformation generated at the time of coupling and fixing. It is difficult to make close contact with each other.

As a result, the heat transfer from the disc 1 to the wheel 12 is performed by the disc 1 and the wheel 12.
And will be performed in the part where they are in partial contact.
The conventional disk 1 does not take into consideration the effective heat transfer in this portion. The same applies to a drum for a drum brake. In view of such circumstances, the rotating body for a braking device and the combination of the rotating body for a braking device and the wheel of the present invention effectively transfer heat from the rotating body for a braking device such as a disk or a drum to the wheel. It was invented to realize a structure that can be performed.

[0009]

A rotating body for a braking device according to the present invention is made of a first kind of material and has a friction surface for pressing a friction material and a mounting surface for abutting against a wheel. In particular, in the rotating body for a braking device of the present invention, at least a portion of the mounting surface that comes into contact with the wheel has a higher thermal conductivity than the first type material, copper,
It has a film made of a second type of material such as silver or gold.

[0010]

In the case of the braking device rotating body of the present invention configured as described above, the film made of the second type material having a large thermal conductivity is provided at the contact portion between the braking device rotating body and the wheel. Will exist. Due to the presence of this film, the highly heat-conductive material is exposed on the mounting surface for abutting against the wheel in the rotating body for the braking device, and the heat conduction from the rotating body for the braking device to the wheel side is caused. The efficiency is good, the heat dissipation effect (cooling effect) is good, and the temperature rise of the braking device rotating body can be suppressed. Further, the coating film and the mounting surface of the braking device rotating body are securely in contact with each other over the entire surface, and the heat transfer from the braking device rotating body to the coating film is efficiently performed.

[0011]

1 to 5 show a first example of an embodiment of the present invention. This example is a kind of rotating body for a braking device, and shows a case where the present invention is applied to a ventilated disk 7 to be mounted on a wheel. First, this ventilated disc 7 and wheel 1
2 will be described with respect to the structure of the portion that is rotatably supported by the knuckle 13 that constitutes the suspension device.

A hub 15 is provided inside the mounting hole 14 of the knuckle 13 by a hub bearing 16 which is a double row rolling bearing.
It is rotatably supported. These hub 15 and hub bearing 1
6 constitutes a hub unit 10 for rotatably supporting the ventilated disc 7 and the wheel 12 with respect to the knuckle 13. The constant velocity joint 17 allows the hub 15 to be rotationally driven. Further, the ventilated disc 7 is formed on the outer surface of the mounting flange 11 formed on a portion of the outer peripheral surface of the hub 15 projecting from the mounting hole 14 (the surface which is the outer side in the width direction when mounted on a vehicle). Also, the wheel 12 is fixedly connected.

For this reason, the mounting flange 11 has a structure shown in FIG.
As shown in FIG. 3, a plurality of studs 18, 18 are provided so as to project from the outer surface of the mounting flange 11.
The ventilated disc 7 and the wheel 12
Inserts the studs 18, 18 into through holes formed at positions aligned with each other, and further, these studs 18, 1
The nuts 19 and 19 are screwed onto the tip portion of 8 and further tightened, so that they are joined and fixed to the hub 15. In this state, the mounting portion 9 of the ventilated disc 7
Are sandwiched between the mounting flange 11 and the wheel 12. Further, the cylinder body 2 and the pads 5, 5 which are combined with the ventilated disc 7 to form a disc brake are supported by a support (not shown) fixed to the knuckle 13.

In particular, in the case of this example, a coating 21 is formed on a flat mounting surface 20 facing the wheel 12 on both axial side surfaces of the mounting portion 9 of the ventilated disk 7.
It is provided over the entire surface of the mounting surface 20. This film 2
1 constitutes the ventilated disc 7;
Cast iron or light alloy, which is the first kind of material, and copper, silver, gold, etc., which has a higher thermal conductivity than the third kind of material, which is the steel or light alloy that composes the wheel 12 above. It is composed of two kinds of materials. The film 21 is formed by plating, thermal spraying, firing or the like, and the film 21 and the mounting surface 20 are adhered to each other without a gap. Accordingly, the mounting surface 20 which is the outer surface of the mounting portion 9 of the ventilated disc 7 and the central portion of the inner surface of the wheel 12 (the side surface near the center in the width direction when mounted on the vehicle) are provided. The flat abutting surface 22 is abutted via the film 21. The second type of material is selected in consideration of heat transfer and corrosiveness. For example, when the first type material and the third type material are iron-based alloys, it is preferable to use inexpensive copper as the second type material. On the other hand, when the first type material and the third type material are aluminum-based alloys, copper may be used depending on the use conditions. It is preferable to use silver or gold in consideration of corrosion prevention of some materials.

In the case of the structure of the present embodiment configured as described above, the abutting portion between the ventilated disk 7 and the wheel 12, that is, the mounting surface 20 and the abutting surface 22.
A state where the film 21 made of the second type material having a large thermal conductivity is present at the abutting part with. This film 21
Is coated in close contact with the mounting surface 20 of the ventilated disc 7, and heat is efficiently transferred from the ventilated disc 7 to the film 21. That is, at the time of braking, the friction plate portion 8 and the pads 5, 5 are
The thermal energy generated based on the friction with
Efficiently transmitted to 1.

A small air layer is partially interposed between the surfaces of the film 21 and the wheel 12 that face each other, that is, between the mounting surface 20 and the butting surface 22, as in the conventional case. Ready to go. Even in this case, since the film 21, that is, the high thermal conductive material is exposed toward the wheel 12, the heat radiation effect from the ventilated disc 7 to the wheel 12 side is enhanced. Further, in the portion other than the air layer, the film 21 made of the second type material and the wheel 12 having good thermal conductivity are provided.
And the abutting surface 22 of. Therefore, heat transfer from the ventilated disc 7 to the wheel 12 at this contact portion is performed more effectively than in the case of the conventional structure, and the ventilated disc 7 to the wheel 12 is transferred. The amount of transfer of heat energy to 12 can be increased.

Moreover, the second type of material is relatively soft, such as copper, silver, gold, etc., and is a mating surface, that is, the abutting surface 22.
It is easy to get used to. Therefore, as shown in FIG.
Even if the shape of the part of the part facing the mounting part 9 is not flat, the area of the part where the abutting surface 22 and the film 21 actually contact each other does not have the film 21. Can be wider than in the case of construction. That is, claim 2
As described in (1), the hardness of the second kind of material forming the film 21 can be changed so as to be able to be deformed following the surface shape of the contact surface of the wheel contacting the mounting surface 20 and the vicinity thereof. By making the hardness lower than the hardness of the third type material forming the wheel 12, the contact area between the film 21 and the abutting surface 22 can be easily secured. Incidentally, FIG.
As shown in (A), the thickness of the coating film 21 covering the mounting portion 9 is set to 10 μm or less at a portion where a part of the wheel 12 is abutted (opposed to the convex portion) and is not abutted (concave portion). Thicker than this (10μ)
m or more and several mm or less), as shown in FIG.
The area of the portion where the abutting surface 22 and the film 21 actually abut can be sufficiently widened. In any case, since the film 21 is provided on the ventilated disk 7 side, the above-mentioned function can be ensured even when the wheel 12 is replaced.

According to the structure of this example, the amount of heat energy flowing from the ventilated disc 7 to the wheel 12 is increased so that the heat generated during braking causes the ventilated disc 7 to move. The temperature rise can be kept low. FIG. 7 shows the results of the JASO fade test that the present inventor actually incorporated into a vehicle. In this test, the temperature of the ventilated disk 7 was changed as shown by the solid line α in FIG. 7 by repeating and stopping the braking. With such a temperature change of the ventilated disc 7, the wheel 12 and the first kind of material (aluminum-based composite material) constituting the ventilated disc 7 are formed as in the conventional structure described above. When the third type material (aluminum alloy), which is a metal, was directly butted, the temperature of the portion near the center of the wheel 12 provided with the butted surface 22 changed as shown by the solid line β in FIG. 7. On the other hand, like the structure of this example,
In the case of the structure in which the coating 21 made of the second type material (copper) is provided, the temperature of the same portion changes as shown by the chain line γ in the figure. As is clear from a comparison between the solid line β and the chain line γ, the structure of this example allows the heat energy generated during braking to be effectively passed through the wheel 12.

Next, FIG. 8 shows a second embodiment of the present invention.
An example is shown. In the case of this example, in addition to forming the film 21 made of the second type material having good thermal conductivity on the outer surface of the mounting portion 9 provided in the portion near the inner diameter of the ventilated disk 7, A heat insulating film 23 made of a material having a low thermal conductivity is formed on the inner surface of the mounting portion 9. As such a heat insulating film 23, a ceramic sprayed film can be adopted in addition to a coating film made of a highly functional resin having heat resistance and compression resistance.

In the case of the structure of this example having such a heat insulating film 23, the heat of the ventilated disk 7 is prevented from being transferred to the hub unit 10 (see FIG. 1), and the temperature of the hub unit 10 is prevented. The rise can be suppressed and the durability of the hub unit 10 can be improved. The structure and operation of the other parts are the same as in the case of the above-described first example, and therefore illustration and description of the equivalent parts are omitted.

In any of the embodiments, the film 2
The thickness of 1 is preferably 10 μm or less. The reason for this is that the settling of the film 21 is suppressed and each stud 1
Nuts 1, 1 screwed onto the tips of 8, 18 and tightened further
This is to prevent the loosening of No. 9. That is, as described above, the second type of material forming the film 21 is a relatively soft metal such as copper, silver, or gold. Therefore, when the thickness of the film 21 increases, the amount of decrease in the thickness of the film 21 due to settling may not be negligible. In this case, the nuts 19 and 19 may loosen. On the other hand, the thickness of the film 21 is 10 μm.
If it is suppressed below, the thickness of the film 21 will not decrease as the nuts 19, 19 loosen.

The above description has been made for the case where the present invention is applied to the ventilated disk 7. Since the purpose of the present invention is to suppress the temperature rise of the disk during braking to a low level, the ventilated disk 7 is used.
It is preferable to carry out with regard to obtaining the best effect. However, the present invention is not limited to the ventilated type disk, but the solid disk 6 as shown in FIG.
Of course, the present invention can be applied to other braking device rotary bodies such as drum brake drums (not shown).

Further, the material and shape of the wheel combined with the brake disc of the present invention are not particularly limited. However, it is preferable to use the wheel 12a having the structure shown in FIG. 9 from the viewpoint of suppressing the temperature rise of the rubber tire while suppressing the temperature rise of the brake disc. The wheel 12a includes a wheel disc portion 24 made of a third type material that is a metal and a tire 25 on the outer peripheral side.
This wheel disc part 2 for mounting (see FIG. 1)
4 and a wheel rim portion 26 provided on the outer peripheral edge portion of Then, the wheel disc portion 24 and the wheel rim portion 26 are made of different metals.

Specifically, the wheel disc portion 24
Is made of a third type material having good thermal conductivity, such as steel, aluminum alloy, and magnesium alloy. On the contrary,
The wheel rim portion 26 is made of a fourth type material (for example, titanium alloy) which is a metal and has a lower thermal conductivity than that of the third type material. By thus suppressing the thermal conductivity of the wheel rim portion 26 to a low level, it is possible to prevent the temperature of the tire 25 from rising due to the heat during braking, and to ensure the durability of the tire 25. Since it is difficult to weld titanium alloy, the wheel rim portion 26 made of titanium alloy and the above-mentioned wheel disc portion 24 are joined and fixed to each other by projecting partly on the inner peripheral surface of the wheel rim portion 26, as shown in FIG. It is preferable that the convex portion 27 is caulked and fixed to a mounting hole 28 portion formed in a part of the wheel disc portion 24. By adopting such a structure, the wheel rim portion 2 described above can be used without incorporating a troublesome seal structure.
The air in the tire 25 can be prevented from leaking from the fixed joint between the wheel disc portion 24 and the wheel disc portion 6. Further, in order to obtain the effects described above, the surface of the outer peripheral surface of the wheel that comes into contact with the tire 25 has a required heat resistance and a small thermal conductivity due to a highly functional resin or the like. It is also effective to form a film made of material.

[0025]

EFFECTS OF THE INVENTION The present invention is constructed and operates as described above, but since the high thermal conductive material is exposed on the mounting surface for abutting against the wheel in the rotating body for the braking device,
The efficiency of heat transfer (cooling efficiency) from the rotating body for braking device to the wheel is improved, and the temperature rise of the rotating body for braking device can be suppressed. When the rotating body for a braking device is a disc made of an aluminum alloy having good heat conductivity, heat transfer to the wheel is further improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention in a state of being incorporated in a suspension device.

FIG. 2 is a schematic perspective view showing a brake disc taken out.

FIG. 3 is a view of the same seen from the right side of FIG.

FIG. 4 is an enlarged AA sectional view of FIG.

FIG. 5 is a perspective view of a mounting flange of the hub unit.

FIG. 6 shows a connecting portion between a brake disc and a wheel,
FIG. 3 is a partial cross-sectional view showing a state before being joined and a state after being joined.

FIG. 7 is a diagram showing the results of a test conducted to confirm the effect of the present invention.

FIG. 8 is a view similar to FIG. 4, showing a second example of the embodiment of the present invention.

FIG. 9 is a partial sectional view showing an example of a wheel that is preferably combined with the brake disc of the present invention.

FIG. 10 is a partial sectional view of a disc brake.

FIG. 11 is a perspective view of a conventionally known solid disk.

FIG. 12 is a perspective view of a ventilated disc.

[Explanation of symbols]

1 disc 2 cylinder body 3 cylinders 4 pistons 5 pads 6 solid disk 7 Ventilated disc 8 Friction plate part 9 Mounting part 10 Hub unit 11 Mounting flange 12, 12a wheel 13 knuckles 14 mounting holes 15 hubs 16 hub bearing 17 constant velocity joint 18 studs 19 nuts 20 Mounting surface 21 film 22 Butt face 23 Thermal insulation film 24 wheel disc part 25 tires 26 Wheel rim 27 convex 28 mounting holes

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeo Shingyoji             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Yoshio Ogata             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Shuichi Nakagawa             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Hidetoshi Suzuki             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation F term (reference) 3J058 AA48 AA53 AA63 AA69 AA77                       AA87 BA32 CB14 CB23 DD02                       DE01 EA08 FA01

Claims (6)

[Claims] 1. A rotating body for a braking device, which is made of a first kind of material and has a friction surface for pressing a friction material and a mounting surface for abutting against a wheel, and at least one of the mounting surfaces. A rotating body for a braking device having a film made of a second type material having a thermal conductivity higher than that of the first type material, in a portion in contact with the wheel. 2. The hardness of the second type material comes into contact with the mounting surface when the wheel is mounted on the mounting surface.
The rotating body for a braking device according to claim 1, wherein the hardness is such that it can be deformed following the surface shape of the contact surface of the wheel and the vicinity thereof. 3. The thickness of the film is 10 μm or less,
The rotating body for a braking device according to claim 1. 4. The rotating body for a braking device according to claim 1, wherein the first type material is an aluminum alloy or an aluminum-based composite material. 5. The braking device rotating body according to claim 1, and a wheel combined with the braking device rotating body, wherein the wheel is made of a metal of a third type. And a wheel disc portion to be superposed on the rotating body for the braking device, and a metal provided on the outer peripheral edge portion of the wheel disc portion for supporting the tire and having a thermal conductivity smaller than that of the third type material. And a wheel rim portion made of the fourth kind of material, which is a combination of a rotating body for a braking device and a wheel. 6. A coating made of a rotating body for a braking device according to any one of claims 1 to 4 and a wheel combined with the rotating body for a braking device, the coating being made of a material having a thermal conductivity smaller than that of the wheel. A combination of a rotating body for a braking device and a wheel, which has a contact surface with the tire around the wheel.