JPH0470495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disc brake used in a vehicle such as a motorcycle, and more particularly to a device for actively cooling the disc plate thereof.

[Prior Art] This type of disc brake has the advantage that since the disc plate is exposed outside the wheel hub, it has better heat dissipation than a drum brake and is less prone to fade.

[Problems to be Solved by the Invention] However, even if the disc plate is exposed outside the hub, only the cooling air obtained by driving is guided to the disc plate, so it is difficult to solve the problem, especially when the driving speed is high. If it is relatively low,
The amount of cooling air guided to the disk plate is substantially reduced.

Therefore, there is a problem in that it becomes difficult to actively cool the disk plate, and the cooling effect of the disk plate becomes correspondingly low.

The present invention was developed based on the above circumstances, and it is possible to actively guide running air to the braking friction part of the disc plate, thereby increasing the cooling effect of this braking friction part, and furthermore, it is possible to improve the cooling effect of the braking friction part of the disc plate. In addition, even if rainwater gets into the inside of the wind guide cover along with the driving wind, this rainwater can be prevented as much as possible from blowing out towards the braking friction part, and the wind guide cover The purpose of the present invention is to provide a cooling device for a disc brake capable of suppressing the airflow noise of running wind flowing in a passage.

[Means for Solving the Problems] Therefore, in the present invention, the axle support member includes:
The wheel hub is rotatably attached via the axle,
In this disc brake, a disc plate is attached to the side surface of the wheel hub, which rotates together with the wheel and has a ring-shaped braking friction part that is sandwiched by the brake pads. A disc-shaped air guide cover is provided on the inside surrounded by the hub, and the peripheral edge of the through hole through which the axle passes through is clamped and fixed between the hub and the axle support member, and the air guide cover is fixed to the hub and the axle support member. An air guide passage is formed between the side surface of the vehicle and the air guide cover, and an inlet is provided in the air guide cover to take in the wind from the front into the air guide passage.
A gap is provided between the outer circumferential edge of the air guide cover and the inner circumferential edge of the braking friction part for blowing out the traveling air taken into the air guide passage toward the braking friction part, and The hub has a hollow shape with a cavity inside, and on the side of the hub,
A communication hole is formed to communicate the cavity and the air guide passage, and the inner diameter of the hub, including the inner circumferential surface of the cavity, is formed to be largest at the center portion along the width direction of the hub, and the center portion The inner surface on the outer circumferential side of the above-mentioned cavity is formed as an inclined surface slanting radially inward from the center of the hub toward the side surface of the hub by gradually decreasing the size from the center toward the side surface of the hub. It is characterized by

[Function] According to this configuration, while driving, the wind from the front flows into the air guide passage between the air guide cover and the hub through the inlet of the air guide cover, and from there flows between the air guide cover and the disk plate. It blows out toward the friction braking part through the gap between the friction braking surface and the friction braking surface. At this time, the gap restricts the flow of the traveling wind, so the traveling wind that has flowed into the wind guide passage between the wind guide cover and the hub is blown out toward the friction braking part at an increased flow velocity. Become.

Therefore, the brake friction part that generates heat during braking has
Compared to conventional natural ventilation disc brakes,
A sufficient amount of running air is forcibly guided, and the cooling effect of this braking friction part can be enhanced.

In addition, since the air guide cover is clamped and fixed between the axle support member and the hub, there is no need for a special structure to fix the air guide cover or structural changes on the disc brake side. It can be easily fixed using the enclosed dead space.

Moreover, if rainwater enters the air guide passage along with the driving wind, the rainwater is heavier than air, so it cannot follow the flow of the air in the air guide passage, and the rainwater gets stuck on the side of the hub or inside of the air guide cover. adhere to. Then, since there is a communication hole in the side of the hub that communicates the air guide passage with the cavity inside the hub, some of the rainwater enters the cavity through the communication hole, and the wheels are heated inside this cavity. It is diffused radially outward of the hub due to the centrifugal force that accompanies rotation. At this time, the inner surface of the outer circumferential side of the empty chamber is sloped so that the central part along the width direction of the hub is the deepest, so rainwater is stored in this area and does not flow out of the empty chamber. is prevented.

Therefore, a portion of the rainwater that has entered the air guiding passage is taken into the hub as it is, so that the amount of rainwater that blows out from the gap to the braking friction portion can be suppressed to a small amount.

In addition, a portion of the traveling wind guided into the air guiding passage also flows into the empty space of the hub, so that the volume of the air guiding passage is expanded by the amount of this empty space. For this reason, the empty chamber functions as a so-called resonator, and it is possible to suppress the airflow noise when the traveling wind flows in the air guide passage without providing a special noise reduction device.

[Embodiment] An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a front wheel of a motorcycle.

Figure 1 shows the front area of a motorcycle.
Reference numeral 1 in the figure is a frame, and a front fork 4 is pivotally supported on a head pipe 2 at the front end of the frame. This front fork 4 is steered by a handle 3.

The front fork 4 includes a pair of left and right outer tubes 5 that serve as axle support members. An axle 6 is installed between the lower ends of these outer tubes 5, and this axle 6 rotatably supports a front wheel 7. As shown in FIGS. 3 and 4, the front wheel 7 includes a hub 8, a rim 9, and a plurality of spokes 10 connecting these two, and the hub 8, rim 9, and spokes 10 are made of aluminum, for example. It is integrally cast from alloy etc. The hub 8 has a hollow shape with a cavity 8a inside. The inner diameter of the hub 8, including the inner circumferential surface of the cavity 8a, is the largest at the center along the width direction of the hub 8, and gradually decreases from the center toward the sides of the hub 8. It is formed. Therefore, the inner surface on the outer peripheral side of the empty chamber 8a forms an inclined surface 8b that is inclined radially inward from the center of the hub 8 toward the left and right side surfaces of the hub 8. A boss portion 11 through which the axle 6 passes is formed at a position passing through the center of the hub 8.
The axle 6 is rotatably supported on the inner surface of the boss portion 11 via a bearing 12. A collar 13 is attached to the outer periphery of the axle 6 between the bearing 12 and the outer tube 5, and a spacer 14 is interposed between the bearings 12.

By the way, disk brakes 15 for braking the front wheel 7 are attached to both left and right side surfaces of the hub 8. Since these disc brakes 15 have the same structure, one side will be explained as a representative.

That is, a disc plate 16 is fastened and fixed to the side surface of the hub 8 via screws 17, and the disc plate 16 is adapted to rotate together with the front wheel 7.

Further, a caliper 24 that straddles the disk plate 16 is attached to the rear surface of the outer tube 5. A pair of brake pads 25 are housed in the caliper 24, and by sandwiching the disc plate 16 between these brake pads 25, frictional resistance is applied to the disc plate 16, so that braking force is generated. It's summery.

This disc plate 16 is provided with a ring-shaped braking friction portion 16a that is held between brake pads 25. This friction braking section 16a is
Two ring-shaped disc rotors 18, 19
A large number of involute curved fins 20 are protruded from the abutment surface of the outer disk rotor 19 at intervals in the circumferential direction. The disc rotors 18, 19 are spaced apart from each other by the protruding height of the fin 20, and there is a gap between the disc rotors 18, 19 and the fin 20 on the inner and outer end surfaces of the braking friction portion 16a. An open air guide path 21 having a constant width is formed.

Therefore, when the disc plate 16 is rotated together with the front wheel 7, outside air is blown in through the inner circumferential opening 22 of the air guide path 21 due to its centrifugal action, and this outside air flows through the air guide path 21. It is discharged outward from the outer peripheral side opening 23. Therefore, outside air flows in the air guide path 21 from the inside in the radial direction of the braking friction portion 16a toward the outside.

A wind guide cover 26 is attached to the outside of the hub 8, located inside the hub 8 surrounded by the braking friction portion 16a of the disk plate 16. The wind guide cover 26 has a disc shape, and the axle 6 passes through a through hole 27 formed in the center thereof.
The peripheral edge of the opening of the through hole 27 is clamped and fixed between the outer tube 5 and the collar 13. The air guide cover 26 has a duct portion 28 formed in front of the outer tube 5 and projecting laterally. An inlet 29 is formed at the front end of the duct portion 28 and is open toward the front to take in air from the vehicle. As shown in FIG. 4, the outer wall 30 of the duct portion 28 is inclined in a direction that approaches the hub 8 as it moves backward.
8 passage area is gradually narrowed down.

The air guide cover 26 is spaced apart from and opposed to the outer surface of the hub 8, and between the air guide cover 26 and the hub 8, an air guide passage 31 is formed which is connected to the introduction port 29. The outer peripheral edge of the wind guide cover 26 is
It is close to the inner peripheral edge of the braking friction portion 16a of the disc plate 16, that is, to the outside of the inner peripheral opening 22 of the air guide path 21. Between the outer peripheral edge of the air guide cover 26 and the inner peripheral edge of the braking friction part 16a, a gap 33 that is connected to the air guide passage 31 is formed continuously in the circumferential direction. The running wind taken in through the introduction port 29 is blown out toward the braking friction portion 16a.

In addition, communication holes 35 are opened on the left and right side surfaces of the hub 8 facing the air guide passage 31, allowing communication between the inner chamber 8a of the hub 8 and the air guide passage 31. Therefore, a portion of the traveling wind flows into the empty chamber 8a through the communication hole 35, and this empty chamber 8a becomes a part of the air guide passage 31.

According to this configuration, while the vehicle is running, the inlet 29 of the wind guide cover 26 takes in the running wind from the front into the wind guide passage 31, as shown in FIG. As shown in FIGS. 3 and 4, this taken-in running air flows from the gap 33 between the wind guide cover 26 and the brake friction part 16a of the disc plate 16 to the inner peripheral end surface of the friction brake part 16a. It blows out towards you. At this time, the duct portion 28 of the wind guide cover 26 is
Since the area of the passage is gradually narrowed toward the rear, the wind from the front is guided into the wind guide passage 31 with its flow velocity increased. At the same time, since the gap 33 connected to the air guide passage 31 also restricts the flow of the traveling air, the flow velocity of the traveling air blown out from this gap 33 toward the braking friction portion 16a increases.

Therefore, a sufficient amount of running air is forcibly guided to the braking friction surface 16a of the disc plate 16, which generates heat during braking, and the braking friction is reduced compared to conventional natural ventilation type disc brakes. Part 16
The cooling effect of a can be enhanced.

In addition, in the case of this embodiment, a part of the running wind blown out from the gap 33 is forcibly sent into the air guide path 21 of the disk plate 16, so that the flow of the running air in this air guide path 21 is good. becomes.

Therefore, there is no need to widen the distance between the disk rotors 18 and 19 in order to improve the flow of running air, so the cooling effect of the disk plate 16 can be enhanced with the minimum necessary distance, and the ventilation disk The original performance can be fully demonstrated.

Furthermore, the thickness of the disk plate 16 can be made thinner than a conventional ventilated disk having equivalent cooling performance. For this reason, hub 8
The mounting space for the disc brake 15 can be reduced, and the disc brake 15 can be made smaller.

Furthermore, according to the above configuration, the wind guide cover 26
is fixed by being inserted between the outer tube 5 of the front fork 4 and the collar 13 on the hub 8 side, so a special configuration for fixing this air guide cover 26 and a structural change of the disc brake 15 are not required. No longer needed. For this reason, the air guiding cover 26 is
can be fixed, has a simple structure, requires fewer parts, and has the advantage of being inexpensive.

On the other hand, since the inlet 29 of the wind guide cover 26 is opened forward, when the vehicle is running in the rain, rain water enters into the air guide passage 31 through the inlet 29 along with the running wind.

However, since rainwater is heavier than air, it cannot follow the flow of the traveling wind within the wind guide passage 31, and most of the rainwater falls on the side of the hub 8 or the wind guide cover 26.
adheres to the inner surface of the Then, on the side of hub 8,
Since the communication hole 35 that communicates the air guide passage 31 with the cavity 8a inside the hub 8 is opened, a part of the rainwater enters the cavity 8a through the communication hole 35, and also flows into the cavity 8a. In response to the centrifugal force generated by the rotation of the front wheel 7, the particles are diffused radially outward of the hub 8 and adhere to the inner surface of the outer circumferential side of the cavity 8a. At this time, since the inner surface on the outer circumferential side of the empty chamber 8a forms an inclined surface 8b which is inclined so that the central part along the width direction of the hub 8 is the deepest, rainwater is stored in this deep central part. This prevents the empty chamber 8a from flowing outward.

From this, according to the above configuration, the air guiding passage 3
A part of the rainwater that has entered the hub 8 can be directly taken into the empty chamber 8a inside the hub 8, and the gap 33
The amount of rainwater that blows out toward the braking friction portion 16a can be substantially suppressed.

At the same time, a part of the traveling wind guided into the air guide passage 31 also passes through the communication hole 35 into the empty space 8a of the hub 8.
Therefore, the passage volume of the air guide passage 31 is expanded by the amount of this empty space 8a. Therefore, the empty chamber 8a functions as a so-called resonator, and it is possible to suppress the airflow noise generated when the traveling wind flows in the air guide passage 31 without providing a special noise reduction device.

Note that the disc brake cooling device according to the present invention is not limited to the front wheel of a motorcycle, but can be similarly applied to the rear wheel, and can be applied not only to motorcycles but also to other vehicles. can do.

[Effects of the Invention] According to the present invention described in detail above, the running wind that has flowed in between the air guide cover and the hub is blown out toward the sliding friction part of the disc plate, so that the sliding friction part that generates heat during braking is not affected. In this case, a sufficient amount of running air is forcibly guided, and the cooling effect of the friction braking part can be enhanced compared to conventional natural ventilation type disc brakes.

Moreover, there is no need for special configurations or structural changes to the disc brake itself to fix the air guide cover, so the air guide cover can be easily fixed using the dead space surrounded by the braking friction part. .

In addition, if rainwater enters the air guide passage along with the driving wind, the rainwater, which is heavier than air, will adhere to the side of the hub and the inner surface of the air guide cover, and enter the air space from the side of the hub through the communication hole. In this cavity, it is diffused radially outward of the hub under the influence of centrifugal force caused by the rotation of the wheel. At this time, the inner surface of the outer periphery of the empty chamber is sloped so that the central part along the width direction of the hub is the deepest, so rainwater will be stored in this deeper central part, and the outer surface of the empty chamber will be The outflow to the other direction is prevented. Therefore, a portion of the rainwater that has entered the air guiding passage can be directly taken into the hub, and the amount of rainwater that blows out from the gap to the braking friction portion can be suppressed to a small level.

In addition, a portion of the traveling wind guided into the air guiding passage also flows into the empty space of the hub, so that the volume of the air guiding passage is expanded by the amount of this empty space.
Therefore, the empty chamber functions as a so-called resonator, and it is possible to suppress the airflow noise generated when the traveling wind flows in the air guide passage without providing a special noise reduction device.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view of the front of the motorcycle, Fig. 2 is a side view of the disc brake, and Fig. 3 is a cross-sectional view taken along the line - in Fig. 2. Fig. 4 is in Fig. 2 -
It is a sectional view along a line. 5... Axle support member (outer tube), 6...
Axle, 7... Wheel (front wheel), 8... Hub, 8a... Vacant room,
8b... Sloped surface, 15... Disc brake, 16...
Disc plate, 16a...braking friction part, 25...
Brake pad, 26... Air guide cover, 27... Through hole, 29... Inlet, 31... Air guide passage, 33... Gap, 35... Communication hole.

Claims (1)

[Scope of Claims] 1. A wheel hub is rotatably attached to the axle support member via the axle, and a ring is provided on the side surface of the wheel hub, which rotates together with the wheel and is sandwiched by the brake pads. In a disc brake equipped with a disc plate having a shaped braking friction part, a disc-shaped air guide cover is provided on the inside surrounded by the braking friction part of the disc plate, and this air guide cover is arranged so that the axle is connected to the disc brake. The peripheral edge portion of the through hole is clamped and fixed between the hub and the axle support member to form an air guide passage between the hub and the side surface of the hub, and guide the running wind from the front to the air guide cover. An inlet is provided to take the air into the air passage, and between the outer peripheral edge of the air guide cover and the inner peripheral edge of the braking friction part, the running air taken into the air guide passage is introduced into the braking friction part. A gap is provided for blowing air toward the air, and the hub has a hollow shape with a cavity inside, and a communication hole is formed in the side surface of the hub to communicate the cavity and the air guide passage. At the same time, the inner diameter of the hub, including the inner circumferential surface of the above-mentioned cavity, is formed to be largest at the center portion along the width direction of the hub, and gradually become smaller as it progresses from this center portion toward the side surface of the hub. A cooling device for a disk brake, characterized in that the inner surface on the outer peripheral side of the empty chamber is an inclined surface that is inclined radially inward from the center of the hub toward the side surface of the hub.