JP2003252276A - Rear wheel brake device for saddle type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively buffer impact force applied to a vehicle body side through a rear arm and a rear wheel from a travel road surface side during traveling of a vehicle. <P>SOLUTION: The vehicle 1 has a disc brake 41 capable of braking the rear wheel 8; and a brake hose 43 extending along the upper face of the rear arm 5, supplying pressure oil to the disc brake 41. A caliper 47 of the disc brake 41 is formed with an oil reception port 59 communicating the caliper 47 with a rear end part of the brake hose 43, and an air vent port 60 discharging air inside the caliper 47 to the outside, such that the respective ports 59, 60 open to the front side. The oil reception port 59 is disposed below the air vent port 60, and an air vent valve 62 freely opening and closing the air vent port 60 is provided. The oil reception port 59 and the air vent port 60 are formed such that respective hole centers 63, 64 of the oil reception port 59 and the air vent port 60 extend along the longitudinal direction of the upper face of the rear arm 5 in a side view of a vehicle body 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a saddle-ride type vehicle provided with a hydraulic caliper, a brake hose communicating with the caliper to supply pressure oil to the caliper, and an air vent valve attached to the caliper. The present invention relates to a rear wheel braking device.

[0002]

2. Description of the Related Art A rear wheel braking system for a saddle-ride type vehicle is
Conventionally, there is one disclosed in JP-A-8-2472.

According to the above publication, a motorcycle, which is a saddle-ride type vehicle, is arranged at the rear of the vehicle body frame and extends in the front-rear direction, and the front end portion thereof is so arranged that the rear portion thereof can swing up and down. A rear arm pivotally supported by the vehicle body frame, a shock absorber installed on the vehicle body frame and the rear arm so as to straddle the vehicle body frame and the rear arm, and a rear wheel supported by a rear end portion of the rear arm are provided.

Further, in the above-mentioned motorcycle, when a pedal-operated braking operation portion is operated to be braked, a disc brake which operates by pressure oil supplied from the braking operation portion to enable the rear wheels to be braked, A brake hose that extends in the front-rear direction along the upper surface of the rear arm and flows the pressure oil from the front end side toward the rear end side to supply the pressure oil to the disc brake is supported by the rear arm. The caliper of the disc brake is formed with an oil inlet for communicating the rear end of the brake hose and an air vent for discharging the air inside the caliper to the outside, respectively, The oil receiving port is disposed below the air vent port, and an air vent valve that opens and closes the air vent port is provided.

When an impact force is applied to the vehicle body frame side from the traveling road surface side through the rear wheel and the rear arm during traveling of the motorcycle, the rear wheel and the rear arm integrally swing up and down. The impact force is alleviated by interlocking with the shock absorber.

When the braking operation portion is operated while the motorcycle is traveling, pressure oil from the braking operation portion is supplied to the caliper through the brake hose, and the caliper is operated to brake the rear wheel. Is braked, and thus the motorcycle is braked.

When air is accumulated in the caliper, the compressibility of the air reduces the braking performance of the caliper. Therefore, the air vent valve is opened to discharge the air in the caliper to the outside through the air vent port.

[0008]

By the way, in the above-mentioned prior art, the respective hole centers of the oil receiving port and the air bleeding port extend rearward and upward at a large elevation angle with respect to the upper surface of the rear arm. The rear end of the brake hose communicating with the oil receiving port and the air vent valve that allows the air vent port to open and close are both projected upward so as to be largely separated from the upper surface of the rear arm.

For this reason, since the vertical dimension of the space above the rear arm is narrowed by the air vent valve, when the rear arm swings up and down together with the caliper and the air vent valve by using this space, The swingable range tends to be narrowed by the narrow space described above, which is a cause of impeding the effect of buffering the impact force by the shock absorber described above, which is not preferable.

On the other hand, in order to facilitate the opening / closing operation of the air vent valve, the air vent valve is positioned so as to be separated upward from the rear end portion of the brake hose, and thus, below the air vent valve, It may be possible to secure a wide working space for the operation.

However, in the above arrangement, the air bleeding valve further projects upward, and the vertical dimension of the space above the rear arm is further narrowed, and the swingable range of the rear arm is further narrowed. However, it is not preferable to position the air vent valve above as described above, and therefore, there is a problem in that even if an attempt is made to easily operate the air vent valve, this cannot be easily done.

The present invention has been made by paying attention to the above circumstances. In the case where the rear arm is caused to swing up and down together with the caliper and the air vent valve attached to the caliper while the vehicle is traveling. It is an object of the present invention to increase the swingable range of the rear arm so as to more effectively reduce the impact force applied to the vehicle body frame side from the traveling road surface side through the rear wheel and the rear arm. To do.

It is another object of the present invention to make it easy to open and close the air vent valve that opens and closes the air vent port of the caliper.

[0014]

A rear wheel braking system for a straddle-type vehicle according to the present invention for solving the above-mentioned problems is as follows. In addition, the code added to each term in this section is
The technical scope of the present invention should not be construed as being limited to the contents of the section "Embodiment of the Invention" described below.

According to the first aspect of the present invention, the rear arm 5 is disposed at the rear of the vehicle body frame 3 and extends in the front-rear direction, and the front end portion is pivotally supported by the vehicle body frame 3 so that the rear side of the vehicle body frame 3 is vertically swingable. And a rear wheel 8 supported on the rear end of the rear arm 5, and a disc brake 4 that can be braked by operating with pressure oil supplied from the outside.
1 and a brake hose 43 that extends in the front-rear direction along the upper surface of the rear arm 5 and supplies the pressure oil to the disc brake 41. The caliper 47 of the disc brake 41 supported by the rear arm 5 is provided with An oil receiving port 59 for communicating the rear end of the brake hose 43,
An air vent 60 for discharging the air in the caliper 47 to the outside is formed so as to be opened forward,
The oil receiving port 59 is arranged below the air vent port 60, and the air vent valve 6 is configured to open and close the air vent port 60.
In the rear wheel braking device of the saddle riding type vehicle provided with 2,

In a side view of the vehicle body 2, the oil receiving port 59 and the air venting port 60 are formed so that their respective hole centers 63 and 64 extend along the longitudinal direction of the upper surface of the rear arm 5.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the hole center 64 of the air vent 60 is seen in a side view of the vehicle body 2.
Is gradually approached to the hole center 63 of the oil receiving port 59 as it goes forward.

The invention of claim 3 relates to claim 1 or 2
In addition to the invention of FIG.
It is located in front of 0.

According to the invention of claim 4, in addition to the invention of any one of claims 1 to 3, a hose joint 44 for communicating the rear end portion of the brake hose 43 with the oil receiving port 59 is provided. After the hose joint 44 once extends downward from the oil receiving port 59 side, the extending end portion is bent so that the extending end portion communicates with the rear end portion of the brake hose 43. The bent pipe 68 is provided.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 5, reference numeral 1 is a saddle-ride type vehicle exemplified by a motorcycle, and an arrow Fr indicates the front of the vehicle 1. The right and left described below means the width direction of the vehicle body 2 of the vehicle 1 toward the front.

The vehicle 1 includes a vehicle body frame 3 which constitutes a skeleton of the vehicle body 2 and front wheels which are supported on a front end portion of the vehicle body frame 3 through a front fork (not shown).
A rear arm 5 is disposed behind the lower portion of the vehicle body frame 3 and extends in the front-rear direction, and a front end portion thereof is pivotally supported by a pivot shaft 4 on the lower portion of the vehicle body frame 3 so that a rear side thereof can swing up and down. A rear wheel 8 supported by an axle 7 at the rear end of the rear arm 5 so as to be rotatable about an axis 6 extending in the width direction of the vehicle body 2, and installed so as to straddle the vehicle body frame 3 and the rear arm 5. The vehicle body 2 is supported on the traveling road surface by the front wheels and the rear wheels 8.

The vehicle 1 has the body frame 3
A drive device 10 for traveling drive supported by the vehicle, a chain winding type interlocking mechanism 11 for interlockingly connecting the rear wheels 8 to the drive device 10, and a braking device 1 for braking the vehicle 1.
2 and.

The rear arm 5 constitutes a front end portion of the rear arm 5, and has a base portion 15 pivotally supported by the body frame 3 by the pivot shaft 4, and a pair of left and right portions projecting rearward from the base portion 15. Arm members 16 and 16, and the upper surface of each arm member 16 of these rear arms 5 is
The vehicle body 2 extends substantially linearly in the front-rear direction in a side view, and the arm members 16 and 16 are swingable A up and down as described above. At the rear end of each arm member 16,
Long holes 17 that are long in the front-rear direction are formed so as to penetrate the vehicle body 2 in the width direction. The axle 7 is inserted into each of these long holes 17.
Each end of the axle 7 is movably fitted in the front-rear direction, and the axle 7 is held at a predetermined position in the front-rear direction by a take-up device 18 supported by the arm members 16 and supported by the arm members 16. There is.

The rear wheel 8 is supported by a supporting device 20 at an axially intermediate portion of the axle 7 between the left and right arm members 16, 16. The rear wheel 8 includes a hub 21 located on the axis 6 and a tire supported by the spokes 22 on the hub 21. Also,
The bearing device 20 includes a pair of left and right bearings 25, 25 for supporting the hub 21 of the rear wheel 8 rotatably around the shaft center 6 with respect to the middle portion of the axle shaft 7, and the axle shaft 7.
And the first to third collars 26 to 28 that are fitted onto the.

The first collar 26 is interposed between the left arm member 16 which is one side in the width direction of the vehicle body 2 and the left bearing 25. Further, the second collar 27 is provided between the left and right bearings 25, 25. In addition, the third
The collar 28 is interposed between the right arm member 16 on the other side and the right bearing 25. In addition, the support device 20 is externally fitted to the axle 7, and the left arm member 16 is provided.
A washer 29 interposed between the first collar 26 and the first collar 26, and an annular space formed between each end of the hub 21 and the first and third collars 26, 28 is closed from the outside. A pair of left and right ring-shaped dust seals 30 and 30 are provided.

The drive unit 10 includes the body frame 3
An internal combustion engine supported by the internal combustion engine, a gear reduction type power transmission device 33 connected to the internal combustion engine, and an exhaust pipe 34 that extends from the internal combustion engine to guide exhaust gas. It is located above the right arm member 16 of the rear arm 5 and extends rearward and substantially horizontally.

The interlocking mechanism 11 includes the power transmission device 3
Drive chain wheel attached to the output shaft of No. 3, and the rear wheel 8
A driven chain wheel 37 supported by a fastener is provided on the left side of the hub 21, and an endless chain 38 wound around the drive chain wheel and the driven chain wheel 37.

The braking device 12 is operated by pressure oil supplied from the outside to enable the rear wheel 8 to be braked, and a brake operation supported by the vehicle body frame 3 for pedaling by a rider. Based on the braking operation portion 42 that supplies pressure oil to the disc brake 41, the pressure oil flows by extending in the front-rear direction along the upper surface of the rear arm 5 and flowing from the front end portion toward the rear end portion. Hose 43 for supplying the above to the disc brake 41
And the brake hose 4 on the disc brake 41.
And a hose joint 44 that connects the rear end portions of the brake hose 3, and the brake hose 43 is made of resin and is flexible,
The hose joint 44 is made of metal.

The disc brake 41 has the shaft center 6
The brake disc 45 is supported on the right side of the hub 21 of the rear wheel 8 by a fastener, and is disposed near the upper rear part of the arm member 16 on the right side of the rear arm 5 and is supported by the bracket 46 on the arm member 16. And a caliper 47 that is operated by the pressure oil and can sandwich the outer edge portion of the brake disc 45.

A through hole 49 is formed on the shaft center 6 in a part of the bracket 46, and the through hole 49 and the axle 7 are fitted together. The axle 7 and the through hole 49
A locking tool 50 for locking the other part of the bracket 46 to the right arm member 16 of the rear arm 5 when the and are fitted is provided, and the locking tool 50 is such that the bracket 46 is a shaft of the axle 7. Prevents you from trying to rotate around your heart 6. That is, the bracket 46 is attached to the arm member 1 of the rear arm 5 by the axle 7 and the locking tool 50.
It is supported by 6.

On the other hand, in a state where the axle 7 and the through hole 49 are not fitted, the bracket 46 can be detachably engaged with the arm member 16 of the rear arm 5 by the engagement tool 50. When the bracket 46 is engaged with the bracket 46, the bracket 46 can assume the same position and position as when the bracket 46 is supported by the arm member 16 of the rear arm 5 as described above.

The axle 7 includes the arm members 16 of the rear arm 5, the bearings 25, the first to third collars 26 to 28,
Washer 29, each dust seal 30, and bracket 46
Bolt-shaped axle body 52 that can be inserted into and removed from the axle body 52
And a nut 53 that is screwed to the threaded portion of the axle body 52. By screwing the nut 53, each arm member 16 of the rear arm 5 and the inner race of each bearing 25 on the shaft center 6, First to third colors 26 to 28,
The washer 29 and the pivot shaft 40 are fixed to each other and integrated.

The caliper 47 has the bracket 46.
A housing 55 supported by fasteners, a piston 56 fitted into the housing 55 so as to be slidable in the width direction of the vehicle body 2, and arranged to face an outer edge portion of the brake disc 45; Disk 4
The pad 57 is provided between the outer edge portion 5 and the piston 56.

An oil receiving port 59 for communicating the rear end of the brake hose 43 to the front part of the housing 55 of the caliper 47, and the housing 55 inside the caliper 47.
An air vent 60 for discharging the air accumulated in the upper space such as the space surrounded by the inner surface of the piston 56 and the piston 56 to the outside of the caliper 47, and the oil receiving port 59 and the air vent 60 are respectively forwarded. It is shaped so as to open toward it.

The oil receiving port 59 is arranged in the vicinity of the lower portion of the air vent port 60, and the oil receiving port 59 is located in front of the air vent port 60. Further, a screw type air vent valve 62 is provided which allows the air vent port 60 to be opened and closed manually. This air vent valve 6
2 is disposed on the hole center 64 of the air vent port 60, the threaded portion at the rear end thereof is screwed onto the inner peripheral surface of the air vent port 60, and is attached to the housing 55 of the caliper 47. The front end of the caliper 4
It projects from 7 forward.

In the side view (FIGS. 1 to 3) of the vehicle body 2 and in a plan view, the oil receiving port 59 and the air vent port 60 have their respective hole centers 63 and 64 in the longitudinal direction of the upper surface of the rear arm 5. Is formed so as to extend along. Further, the hole center 64 of the air vent port 60 is gradually brought closer to the hole center 63 of the oil receiving port 59 as it goes forward, and both the hole centers 63, 64 move forward as the rear arm 5 moves. Is gradually separated from the upper surface of the.

In particular, in FIG. 5, the hose joint 44 has a brake hose 43 at the oil receiving port 59.
The rear end portion is made to communicate with each other, and a bolt body 67 is screwed into the oil receiving port 59 from the front side thereof and has an oil passage 66 inside, and an upper end portion is connected to the edge of the oil receiving port 59 by the bolt body 67. After being fastened and extending downward from the upper end side, a bent pipe 68 for bending the extended end toward the front and connecting the rear end of the brake hose 43 to the extended end. I have it. The bent pipe 68 has an arc shape in a side view of the vehicle body 2, and the lower portion of the bent pipe 68 and the rear end of the brake hose 43 are arranged near the upper surface of the rear arm 5. Then, the inside of the brake hose 43 passes through the inner hole of the bent pipe 68 and the oil passage 66 of the bolt body 67 and the oil receiving port 59.
It is in communication with.

The rear end of the brake hose 43, the hose joint 44, the caliper 47, and the air vent valve 62.
A cover body 70 that integrally covers the vehicle from the outside so as to be openable and closable
The cover body 70 is detachably fastened to the bracket 46 by a fastener 71.

When the braking operation portion 42 is operated for braking, the pressure oil from the braking operation portion 42 causes the brake hose 4 to move.
3, the hose joint 44, and the oil receiving port 59 are sequentially supplied to the caliper 47.
The piston 56 in 7 presses the pads 57 against the outer surface of the outer edge portion of the brake disc 45 to frictionally bond them. Then, the rear wheel 8 is braked by braking the brake disc 45.

When the braking operation to the braking operation section 42 is released, the pressure oil in the caliper 47 flows in the opposite direction to the above and is returned to the braking operation section 42, and the brake disc 4
Braking of 5 is released.

According to the above-mentioned structure, the oil receiving port 59 and the air vent port 60 are shown in the side view of the vehicle body 2 with the respective hole centers 6 thereof.
3, 64 are formed so as to extend along the longitudinal direction of the upper surface of the rear arm 5.

Therefore, the brake hose 43 communicated with the oil receiving port 59 is different from the case where each hole center extends rearward and upward at a large elevation angle with respect to the upper surface of the rear arm 5 as in the prior art. The rear end portion and the front end portion of the air vent valve 62 that allows the air vent port 60 to be opened and closed are prevented from being largely separated upward from the upper surface of the rear arm 5.

Accordingly, since the space 69 above the rear arm 5 extending from the rear arm 5 to the exhaust pipe 34 above the rear arm 5 is prevented from being narrowed by the front end portion of the air vent valve 62, the upper and lower parts of this space 69 are prevented. The size can be made larger. Therefore, when the rear arm 5 swings up and down together with the caliper 47 and the air bleeding valve 62 using this space 69, the swingable range can be made larger. , While driving,
The impact force that is applied to the vehicle body frame 3 side from the traveling road surface side via the rear wheel 8 and the rear arm 5 can be more effectively alleviated.

Further, as described above, in the side view of the vehicle body 2, the hole center 64 of the air vent port 60 gradually approaches the hole center 63 of the oil receiving port 59 as it goes forward.

Therefore, for example, the above-mentioned both cores 63, 64
Are parallel to each other, or the hole center 6 of the air vent port 60
According to the above configuration, the air vent valve 6 that allows the air vent port 60 to be opened and closed as compared with the case where the valve head 4 is gradually separated from the hole center 63 of the oil receiving port 59 as the oil front port 4 moves forward.
The front end of 2 can be brought closer to the upper surface of the rear arm 5.

Therefore, the vertical dimension of the space 69 above the rear arm 5 can be further increased. Therefore, by using this space 69, the rear arm 5 with the caliper 47 and the air vent valve 62 is vertically moved. When swinging, the swingable range can be further increased, and accordingly, the impact force that is applied from the traveling road surface side to the vehicle body frame 3 side via the rear wheel 8 and the rear arm 5 during traveling is as follows. It can be more effectively alleviated.

Further, as described above, the oil receiving port 59 is located in front of the air vent port 60.

Therefore, the rear end portion of the brake hose 43 which is communicated with the oil receiving port 59 and the air vent port 6 are connected.
The air vent valve 62 that opens and closes 0 will be offset from each other in the front and rear.

Accordingly, since the opening / closing valve operation of the air vent valve 62 can be performed without being obstructed by the rear end portion of the brake hose 43, the operation of the air vent valve 62 can be performed more easily.

As described above, the hose joint 44 that connects the rear end of the brake hose 43 to the oil receiving port 59 is provided, and the hose joint 44 extends once downward from the oil receiving port 59 side. After that, a bent pipe 68 is provided so that its extended end portion is bent so as to face forward, and the extended end portion communicates with the rear end portion of the brake hose 43.

Therefore, the rear end of the brake hose 43 is separated from the air bleeding valve 62 by the hose joint 44.

Therefore, since the opening / closing valve operation of the air vent valve 62 can be performed more reliably without being hindered by the rear end portion of the brake hose 43, the operation of the air vent valve 62 can be further facilitated.

In FIG. 6, a guide surface 72 is formed at a corner of the rear end portion of the bracket 46 on the side of the rear wheel 8 in the width direction of the vehicle body 2. This guide surface 72
Is a flat inclined surface which approaches the rear wheel 8 side as it goes forward in a plan view of the vehicle body 2 (FIG. 6).

When the axle 7, the rear wheel 8, the interlocking mechanism 11, the support device 20, and the disc brake 41 are assembled to the rear arm 5, first, the engaging member is attached to the right arm member 16 of the rear arm 5. The bracket 46 of the disc brake 41 is locked by 50 so as to be temporarily fixed. At this time, the long holes 1 of the arm members 16 are
7 and the through hole 49 of the bracket 46 are opposed to each other in the width direction of the vehicle body 2.

On the other hand, the rear wheel 8 and the support device 20 are assembled together, and the driven chain wheel 37 and the brake disc 45 are supported by the hub 21 of the rear wheel 8 to form the assembly 73.

Next, the assembly 73 is fitted into the space 74 sandwiched by the arm member 16 on the left side of the rear arm 5 and the bracket 46 from the rear thereof (indicated by the double-dotted chain line arrow in the figure). At this time, the assembly 73 and the space 7
4 has substantially the same outer width dimensions in the width direction of the vehicle body 2, and fitting of the assembly 73 into the space 74 tends to be complicated. However, since the guide surface 72 guides the assembly 73 at the time of this fitting, the fitting can be smoothly performed.

By fitting the assembly 73 into the space 74, the shaft center 6 of the rear wheel 8 in the assembly 73 is fitted into the through hole 4.
9, and in this state, the axle body 52 of the axle 7 is fitted along the axis 6 and a nut 53 is screwed into the axle body 52. 7, take-up device 18, and support device 2
The rear wheel 8 is supported via 0. After this,
While operating the take-up device 18, the chain 3
8 and wrap the caliper 4 on the bracket 46.
Then, the nut 53 may be finally screwed to the axle body 52.

Although the above is based on the illustrated example, the vehicle 1 may be a three-wheeled motor vehicle. Also, the above-mentioned both hole cores 63, 6
4 may gradually approach the upper surface of the rear arm 5 as it goes forward.

[0060]

The effects of the present invention are as follows.

According to a first aspect of the present invention, there is provided a rear arm which is disposed at the rear of the vehicle body frame, extends in the front-rear direction, and has a front end pivotally supported by the vehicle body frame so that a rear side of the vehicle body frame can swing vertically. A rear wheel supported at the rear end portion, a disk brake that is actuated by pressure oil supplied from the outside to enable the rear wheel to be braked, and the pressure oil that extends in the front-rear direction along the upper surface of the rear arm. A brake hose for supplying the disc brake, and an oil receiving port for communicating a rear end portion of the brake hose with a caliper of the disc brake supported by the rear arm, and air in the caliper is discharged to the outside. The air vent and the air vent are formed so as to open toward the front, and the oil receiving port is arranged below the air vent, and the air vent can be opened and closed freely. In the wheel brake after the straddle-type vehicle provided with a vent valve that,

In a side view of the vehicle body, the oil receiving port and the air venting port are formed so that the respective hole centers thereof extend along the longitudinal direction of the upper surface of the rear arm.

Therefore, the rear end of the brake hose communicated with the oil receiving port is different from the case where the respective hole centers extend rearward and upward at a large elevation angle with respect to the upper surface of the rear arm as in the prior art. The part and the air vent valve that opens and closes the air vent are prevented from being largely separated upward from the upper surface of the rear arm.

Therefore, since the space above the rear arm is prevented from being narrowed by the air vent valve, the vertical dimension of this space can be made larger. Therefore, using this space, the rear arm can be made larger. When swinging up and down together with the caliper and the air bleeding valve, the swingable range can be made larger.Thus, while traveling, the swingable range is given to the vehicle body frame side from the traveling road surface side through the rear wheel and the rear arm. The impact force to try is
It can be alleviated more effectively.

According to the second aspect of the present invention, as viewed from the side of the vehicle body, the hole center of the air vent is gradually brought closer to the hole center of the oil receiving port as it goes forward.

Therefore, for example, as compared with the case where the both cores are parallel to each other or the cores of the air vents are gradually separated from the cores of the oil receiving port as they face forward, the above configuration According to this, the air vent valve, which opens and closes the air vent, can be brought closer to the upper surface of the rear arm.

Therefore, it is possible to further increase the vertical dimension of the space above the rear arm. Therefore, when the rear arm swings up and down together with the caliper and the air vent valve using this space, The swingable range can be made even larger, so that
The impact force that is applied to the vehicle body frame side from the traveling road surface side via the rear wheel and the rear arm can be more effectively alleviated.

According to the third aspect of the present invention, the oil receiving port is located in front of the air vent port.

Therefore, the rear end of the brake hose communicating with the oil receiving port and the air vent valve that opens and closes the air vent are displaced from each other in the front-rear direction.

Therefore, the operation of opening and closing the air vent valve is
Since the rear end of the brake hose can be performed without being obstructed, the air vent valve can be operated more easily.

According to a fourth aspect of the present invention, a hose joint for communicating the rear end of the brake hose with the oil receiving port is provided, and after the hose joint is once extended downward from the oil receiving port side, A bent pipe is provided so that the extended end portion is bent forward and the extended end portion communicates with the rear end portion of the brake hose.

Therefore, the rear end of the brake hose is separated further downward from the air vent valve of the air vent by the hose joint.

Therefore, the operation of opening and closing the air vent valve is
Since the rear end of the brake hose can be more reliably not disturbed, the operation of the air vent valve can be further facilitated.

[Brief description of drawings]

FIG. 1 is a view corresponding to FIG. 3, showing a rear arm and a cover body in this figure in phantom lines.

FIG. 2 is a rear side view of a vehicle.

FIG. 3 is a partially enlarged view of FIG.

4 is a cross-sectional view taken along the line 4-4 of FIG.

5 is a partially enlarged partial sectional view of FIG.

FIG. 6 is a development view (oblique lines of the cross section are omitted) of FIG. 4 in plan view.

[Explanation of symbols]

1 vehicle 2 car body 3 body frame 5 Rear arm 6 axis 7 axles 8 rear wheels 12 Braking device 15 base 16 arm members 41 disc brakes 42 Braking operation part 43 Brake hose 44 hose joint 45 brake disc 46 bracket 47 calipers 59 Oil inlet 60 Air vent 62 Air vent valve 63 hole 64 hole core 66 oil passage 67 bolt body 68 Bent pipe 69 space A swingable

Claims (4)

[Claims] 1. A rear arm having a front end pivotally supported by the body frame so that the rear end of the rear arm is disposed rearward of the body frame and extends in the front-rear direction, and the rear side of the rear arm is swingable up and down. A rear wheel that is supported, a disc brake that is actuated by pressure oil supplied from the outside to enable braking of the rear wheel, and extends in the front-rear direction along the upper surface of the rear arm to supply the pressure oil to the disc brake. A brake hose for controlling the disc brake caliper supported by the rear arm, an oil receiving port communicating the rear end of the brake hose, and an air vent for discharging the air inside the caliper to the outside. Molded so as to open toward the front, the oil receiving port is arranged below the air vent port, and an air vent valve is provided to open and close the air vent port. In a rear wheel braking system for a saddle-ride type vehicle, in the side view of the vehicle body, the oil receiving port and the air vent port are formed such that their respective hole centers extend along the longitudinal direction of the upper surface of the rear arm. Rear wheel braking system for vehicles. 2. A rear wheel braking system for a saddle-ride type vehicle according to claim 1, wherein, in a side view of the vehicle body, the hole center of the air vent port is made to gradually approach the hole center of the oil receiving port as it goes forward. apparatus. 3. The rear wheel braking system according to claim 1 or 2, wherein the oil receiving port is located in front of the air vent port. 4. A hose joint that connects the rear end of the brake hose to the oil inlet is provided, and the hose joint temporarily extends downward from the oil inlet side and then the extended end is The rear wheel braking system according to any one of claims 1 to 3, further comprising a bent pipe which is bent so as to be forward and communicates with a rear end portion of the brake hose at the extended end portion. apparatus.