JPH0341231A - Breather device for vehicles traveling on rough terrain - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a breather device for an all-terrain vehicle, and more particularly to a drainage structure in a breather device for a sealed drum brake.

In recent years, vehicles for traveling on rough terrain, commonly referred to as buggy vehicles, have become popular as leisure or practical vehicles. This vehicle is a tricycle or four-wheeled vehicle equipped with low-pressure wide tires called balloon tires, and is capable of driving on rough terrain.
You can also cross swamps, etc.

Such vehicles for running on rough terrain employ sealed drum brakes to prevent water from flowing into the brake drum when the vehicle is running on humid areas. However, when the air pressure inside the brake drum changes due to temperature changes, a load is placed on the sealing portion, so the inside of the brake drum has been made to communicate with the atmosphere. This also applies to the gear box of the final reduction gear when a shaft drive system is adopted as the wheel drive system, and the inside of the gear box is communicated with the atmosphere.

However, since water flows in from these atmospheric communication parts when driving in humid areas, as shown in FIG. By positioning it above the connecting line A, water is prevented from flowing in. (Unexamined Japanese Patent Publication No. 63-65532
Specifically, in the shaft drive type off-road vehicle 01, the gear box 03 of the final reduction gear
Connect the breather pipe 02 to the drive shaft cylinder 0 through which the shaft passes.
A breather pipe 02 is arranged along line A and extends further upward, with its opening end 02a to the atmosphere being above line A and facing downward to prevent rainwater from entering.

When the breather pipe 02 with this structure is applied to a sealed drum brake, it is possible to communicate the inside of the sealed drum brake with the atmosphere and prevent water from entering under normal conditions. However, due to the environment in which it is used as a vehicle for traveling on rough terrain, it may be driven through deeper wetlands, and at that time water will flow into the sealed drum brake from the breather pipe.

Furthermore, when the drive is stopped at night, condensation forms inside the breather pipe.
The water may accumulate inside the sealed drum brake.

The present invention relates to an improvement of a breather device for an all-terrain vehicle that overcomes the above-mentioned difficulties. A breather pipe is provided that communicates with the inside of the case and the other end is open to the atmosphere, a drainage port is formed in the lower part of the case of the sealed drum brake, and a drainage device that communicates with the drainage port is provided. It is.

Since the present invention is configured as described above, the vehicle for traveling on rough terrain repeatedly accelerates and decelerates while driving, and the drum l and brake heat up due to braking, and the air inside the drum case expands. However, the air inside the case is discharged to the atmosphere through the breather pipe, and the pressure inside the case is maintained at atmospheric pressure.

Further, in the present invention, when the tram case is cooled by water and the air in the case contracts when the rough terrain vehicle crosses a swamp or a river, the air is released into the atmosphere through the breather pipe. of air is introduced into the case, and the pressure inside the case is maintained at atmospheric pressure.

Further, in the present invention, water may enter the drum case,
Alternatively, when moisture in the air inside the case condenses and water accumulates inside the case, the water inside the case can be discharged by the drainage device.

An embodiment of the present invention illustrated in FIGS. 2 to 5 will be described below.

A vehicle for traveling on rough terrain 1 has a saddle-type seat 2 on the upper part of the vehicle body.
, a fuel tank 3, a bar handle 4, and a pair of front wheels 5 and rear wheels 6 each having low-pressure wide balloon tires at the front and rear.

Further, the frame of the vehicle body is formed of a pipe frame 7, and an engine 8 is supported approximately at the center in the longitudinal direction.

Furthermore, the output from the engine 8 is configured to be able to swing at a swing shaft portion 9a and to be transmitted to a drive shaft 10 that passes through a drive shaft cylinder 9b that forms a part of the rear fork assembly 9. ing. The drive shaft IO is integrally and rotatably connected to a final drive gear 12 rotatably supported within a gear box 11.

The gear box 11 is also sealed by seals 16, 17, and 18, and is filled with lubricating oil. The gear box 1
1, the final drive gear 12 is meshed with a final driven gear 13 that is rotatable integrally with the rear axle 14, and is adapted to transmit the driving force from the engine 8 to the rear axle 14.

Further, the rear axle 14 is rotatably supported by an axle cylinder 15, and rotates the rear wheel 6 integrally.

On the other hand, a sealed drum brake 2 is provided on the right end of the rear axle 14.
0 is set.

Further, the brake panel 21 of the sealed drum brake 20 is fixed to the axle tube 15 with bolts, and the brake cover 22 is coupled to the rear axle 14 and the rear wheel 6 so as to rotate together.

Further, the adjacent portion between the brake panel 21 and the brake cover 22 is made air-water tight by the seal portion 23, and a brake drum 34 is disposed in a space surrounded by the brake panel 21 and the brake cover 22.

Furthermore, two brake shoes 25 are mounted inside the brake panel 21 so as to be able to swing around an anchor pin 24 in opposition to each other, and a brake cam 26 provided through the brake panel 21 rotates. As a result, the brake shoes 25 are pushed outward against the biasing force of the spring 27 and come into contact with the inner circumferential surface of the brake cover 22 to perform a braking action.

Further, the spring 27 biases the brake shoe 25 inward to separate it from the inner peripheral surface of the brake cover 22.

Moreover, an opening 28 is formed in the brake panel 21, and the inside and outside of the brake panel 21 are communicated with each other.

Further, a breather pipe 30 is attached to the opening 28,
The breather pipe 30 is supported from the rear fork assembly 9 to the upper frame 7a, and its open end 30a is located at the top of the vehicle body and is directed downward.

Furthermore, at the bottom of the brake panel 21, there is a drain port 2.
9 is formed passing through the brake panel 21.

Furthermore, a transparent synthetic resin drainage tube 32 serving as a drainage device 31 is detachably attached to the drainage port 29 with a clip 33.

The embodiment shown in FIGS. 2 to 5 is constructed as described above, and since the inside of the sealed drum brake 20 is communicated with the atmosphere through the breather pipe 30, even if there is a thermal fluctuation, The air pressure inside the sealed drum brake 20 is maintained at atmospheric pressure, and the seal portion 23 is not damaged.

When water enters the sealed drum brake 20 through the breather pipe 30 due to driving in deep water or due to dew condensation inside the breather pipe 30, water is drained from the drain port 29 formed at the bottom of the brake panel 21. and accumulates in the drain tube 32. Since the drain tube 32 is transparent,
It can be confirmed from the outside that water has accumulated, and the water can be removed by loosening the clip 33 and removing the drain tube 32.

Another embodiment of the invention is shown in FIGS. 6 and 7.

A wavy cam surface 40a extending in the axial direction is formed on the outer surface of the brake drum 40, and a drainage device 41 is mounted at a corresponding position to the cam surface 40a.
2 to the shaft cylinder 15.

An intake port 45 is formed in the cylinder 44 constituting the main body of the drainage device 41, and the drainage port 29 of the brake panel 2■ and the intake port 45 are communicated through a pipe 43.

Further, a piston 46 is fitted in the cylinder 44 so as to be able to swing freely, and the piston 46 is urged by a spring 52 in a direction approaching the cam surface 40a and moves along the cam surface 40a of the brake drum 40. roller 4
7 is installed.

Further, an opening 48 is formed in the cylinder 44, check valves 49, 50 are provided in the inlet 45 and the opening 48, respectively, the opening 48 communicates with the outlet 51, and the inlet 45 is connected from the outside to the inside. The opening 48 allows passage of fluid only from the inside to the outside.

Since the embodiment shown in FIGS. 6 and 7 is configured as described above, when water enters the sealed drum brake 20 from the breather pipe 30, the brake drum 40, which is being rotated, Due to the axial displacement of the cam surface 40a, the piston 46 reciprocates via the roller 47, and accordingly, the inside of the cylinder 44 performs a pumping action.

Therefore, water in the sealed drum brake 20 passes through the pipe 43 from the drain port 29 of the brake panel 21, and when the piston 46 slides in the left direction in FIG.
5 is inhaled. The water sucked into the cylinder 44 is pushed out from the opening 48 when the piston 46 slides in the right direction in the drawing, and is drained to the outside from the discharge port 51.

In the case of this embodiment, water can be automatically discharged without manual intervention.

In addition, as another embodiment, the cam surface 4 of the brake drum 40
The pump of the drainage device may be driven by an electric motor instead of the motion of 0a. In that case, the drainage device can be installed closer to the drainage port 29 of the brake panel 21, and the pump can be driven only when necessary.

Yet another embodiment is illustrated in FIG.

Here, the breather pipe 60 is connected to the sealed drum brake 2.
Breather pipe 60a communicating with 0, opening 11 in gear box 11
A breather pipe 60b communicates with the air conditioner through a breather pipe 60b, and both of them are connected to a breather pipe 60c which is exposed to the atmosphere above the vehicle body.

At the intersection 60d that connects these three pipes, the breather pipe 60b connected to the gear box 11 is positioned above, so that water from the breather pipe 60c flows to the breather pipe 60a. ing.

Further, the sealed drum brake 20 is provided with any of the aforementioned drainage devices 31, 41, which are not shown in FIG.

The embodiment shown in FIG. 8 is constructed as described above, and in addition to the sealed drum brake 20, the inside of the gear box 11 is also opened to the atmosphere through the breather pipe 60, so that sealing due to internal pressure changes The burden on the department can be avoided.

On the other hand, when water flows in from the breather pipe 60c, the water flows only to the breather pipe 60a that communicates with the sealed drum brake 20 at the intersection 60d. 3L 41
This allows drainage to the outside.

In the above embodiments, the brake shoes of the sealed drum brake were operated by a cam, but the brake shoes may be operated by a hydraulic cylinder.

Furthermore, although the vehicle for traveling on rough terrain is a four-wheeled vehicle, it may also be a three-wheeled vehicle with one front wheel.

As described above, in the present invention, since the pressure inside the drum case of the sealed drum brake is always maintained at atmospheric pressure,
This prevents the case from deforming due to fluctuations in the internal pressure of the case, and prevents the internal pressure from dropping below atmospheric pressure, preventing water from entering the drum case from outside due to the pressure difference. Ru.

Furthermore, in the present invention, even if water intrudes into the drum case, the water in the case can be discharged by the drainage device, so that braking performance can be maintained sufficiently and the durability of the drum brake can be improved. can improve sex.

[Brief explanation of drawings]

FIG. 1 is a side view of a vehicle for running on rough terrain equipped with a conventional breather device with the left rear wheel removed, and FIG. 2 is a side view of a vehicle for traveling on rough terrain equipped with a breather device according to the present invention. , Fig. 3 is a horizontal cross-sectional view taken along the line ■-■ in Fig. 2, Fig. 4 is a vertical cross-sectional view taken along the rV-rV line in Fig. 2, and Fig. 5 is a cross-sectional view taken along the line ■ in Fig. 4.
6 is a vertical sectional view corresponding to FIG. 4 according to another embodiment, FIG. 7 is an enlarged sectional view of the main part of FIG. 6, and FIG. 8 is a further different embodiment. FIG. 3 is a horizontal sectional view corresponding to FIG. 3 according to the example; 1...Vehicle for traveling on rough terrain, 2...Saddle type seat,
3... Fuel tank, 4... Bar handle, 5...
Front wheel, 6... Rear wheel, 7... Pipe frame, 8... Engine, 9... Rear fork assembly, 10... Drive shaft, 11... Gear box, 12
...Final drive gear, 13...Final driven gear, 14.
... Rear axle, 15 ... Axle cylinder, 16 ... Seal part,
17... Seal portion, 18... Seal portion, 20...
Sealed drum brake, 21...brake panel, 2
2...Brake cover, 23...Seal part, 24.
・・Anchor bin, 25・Brake shoe, 26・
...Brake cam, 27...Spring, 28...
Opening, 29... Drain port, 30... Breather pipe, 31
...Drainage device, 32...Drain tube, 33...
Clip, 34...Brake drum, 40...Brake drum, 41...Drainage device, 42...Metal fittings for installation, 43...Pipe, 44...Cylinder, 45...
Suction port, 46... Piston, 47... Roller, 48
...Opening, 49...Check valve, 50...Check valve, 5
1... Discharge port, 52... Spring, 60... Breather pipe.

Claims (1)

[Claims] In an all-terrain vehicle having a sealed drum brake, a breather pipe is provided, one end of which communicates with the case of the sealed drum brake, and the other end of which is open to the atmosphere;
A breather device for an all-terrain vehicle, characterized in that a drainage port is formed in the lower part of the case of the sealed drum brake, and a drainage device communicating with the drainage port is provided.