JP2538706Y2 - Breather device for engine for rough terrain vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather device for an engine for an off-road vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 3, there is a vehicle in which wide low-pressure tires are attached to wheels so that the vehicle can travel on uneven terrain. This type of vehicle can also travel on a swamp.
The engine is connected to a breather hose that removes blow-by gas from the upper end of the crankcase. In general, there are a breather hose that hangs down to the lower side of the crankcase to open to the atmosphere, and a breather hose that is connected to an air cleaner and sucked into the intake air of the engine.

[0003]

[Problems to be Solved by the Invention] In the case of hanging the breather hose of the crankcase downward and releasing the air to the atmosphere, when the vehicle is stopped in a place where water is present, the air in the crankcase is cooled as the engine cools down. There is a problem that it contracts and water is sucked into the crankcase from the breather hose.

[0004] When a breather hose of a crankcase is connected to an air cleaner and is contained in the intake air, when the engine is overheated and blow-by gas is generated particularly frequently, the proportion of blow-by gas mixed into the intake air is low. As the air-fuel ratio increases, the low-speed rotation becomes unstable or the output decreases.

[0005] In view of the above, this invention is based on the idea that the breather hose at the upper end of the crankcase is opened to the atmosphere by an open hose via the one-way valve during operation of the engine, so that the blow-by gas is not sucked into the intake air and the engine is stopped. It is an object of the present invention to obtain a breather device for an engine for an off-road terrain vehicle that is connected to an air cleaner via a one-way valve by a connecting hose and does not suck water from an open hose.

[0006]

In order to achieve the above-mentioned object, a breather device for an engine for an off-road vehicle according to the present invention has a breather hose connected to an upper end of a crankcase of the engine which branches into two branches. One is connected to an air cleaner via a connecting hose via a one-way valve, and the other is opened downward by an open hose via a one-way valve.

[0007]

During operation of the engine, blow-by gas generated in the crankcase flows from the breather hose to the open hose via the one-way valve, and is discharged into the atmosphere from the lower end of the open hose. During the operation of the engine, since the one-way valve is closed and does not flow into the connection hose connected to the air cleaner, blow-by gas does not mix with the intake air.

When the engine is stopped, the one-way valve on the connecting hose side is connected to the breather hose side from the air cleaner side, and the air in the crankcase is contracted as the air in the crankcase contracts, so that the air is sucked into the crankcase. . Since the open hose does not flow backward with the one-way valve, water is not sucked into the crankcase even if the lower end of the open hose is immersed in water.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The breather hose 2 is connected to the upper end of the crankcase 1 of the engine, the branch 3 is connected to the tip of the breather hose 2, and the breather hose 2 branches into two branches. One of the two branches is connected to an air cleaner 6 by a connecting hose 5 via a one-way valve 4. An open hose 8 is connected to the other of the branches via a one-way valve 7, and the tip of the open hose 8 hangs down below the crankcase 1 to open. On the other hand, as shown in FIG. 2, the valves 4 and 7 have a valve ball 10 pressed against the inlet 9 by a spring 11, and the valve ball 10 is pushed open from the inlet 9 side against the spring 11. Air can flow from the outlet 12 to the valve ball 10 from the outlet 12 side to the inlet 9 side.
Is closed so that it cannot flow. The one-way valve 4 opens only from the air cleaner 6 side to the breather hose 2 side, and the one-way valve 7 opens only from the breather hose 2 side to the tip side of the open hose 8.

The blow-by gas generated in the crankcase 1 during operation of the engine flows through the one-way valve 7 to the open hose 8 and is released to the atmosphere. The blow-by gas does not flow to the air cleaner 6 via the one-way valve 4, and the blow-by gas does not mix into the intake air of the engine. When the engine is stopped and the crankcase 1 cools and the air in the crankcase 1 contracts, air flows into the crankcase 1 from the air cleaner 6. At this time, even if the distal end of the open hose 8 is immersed in water, the one-way valve 7 is closed and there is no backflow in the open hose 8, so that water does not enter the crankcase 1.

[0011]

As described above, since the present invention is configured as described above, the blow-by gas is released to the atmosphere during the operation of the engine, and is not mixed into the intake air from the air cleaner, so that the air-fuel ratio changes. This prevents the engine from malfunctioning. Further, when the engine is stopped and the crankcase cools down, air flows from the air cleaner side to the crankcase, and even if the tip of the open hose is immersed in water, water does not enter the crankcase.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an example of the one-way valve of the present invention.

FIG. 3 is a side view showing an example of an all-terrain vehicle using the present invention.

[Explanation of symbols]

 Reference Signs List 1 crankcase 2 breather hose 4 one-way valve 5 connecting hose 6 air cleaner 7 one-way valve 8 open hose

Claims (1)

(57) [Scope of request for utility model registration] 1. A breather hose connected to the upper end of a crankcase of an engine is branched into two branches, one of which is connected to an air cleaner with a connecting hose via one valve, and the other is opened via one valve. A breather device for an engine on a rough terrain vehicle, wherein the breather device is opened downward by a hose.