JPH04109012A - Breather device - Google Patents

Abstract

PURPOSE:To prevent choke of a breather hose and to make the installation of the breather hose easy by arranging an outlet opening of the breather hose, which leads blow-by gas and the like in a crank case outwards, in a space between a crank case and its cover. CONSTITUTION:An engine to be mounted on a car frame of a motor bicycle has a crank case 22 and a cylinder mounted to this crank case, Turning torque of a crank shaft is transmitted to a driving sprocket wheel 27 through a reduction gear, and rotates a rear wheel through a driving chain 28. In this case, a breather union 29 is arranged projectingly at a rear and upper part of the crank case 22, and a breather hose 30 is connected to this breather union 29. The breather hose 30 reaches curvewise the space between the crank case 22 and a sprocket cover 32, and is fixed to the crank case 22 by means of a clamp 35. Thus, the intrusion of mud, snow and the like into the breather hose 30 during running of the motor bicycle is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a breather device for an engine mounted on a motorcycle.

(Prior art) In a 4-cycle engine, a breather hose is installed in the crankcase because blow-by gas leaks from the high-pressure combustion chamber through the gap between the piston and the cylinder sleeve to the lower part of the piston, increasing the internal pressure of the crankcase. , the blow-by gas is discharged to the outside.

FIG. 3 shows a motorcycle equipped with a first embodiment of the reserve device. This motorcycle has a front wheel 2 supported by a front fork 1 at the front of the vehicle, a rear wheel 4 driven by an engine 3 at the rear of the vehicle, and a rider riding on a seat 5 at the top of the vehicle. The vehicle is driven by operating a steering wheel 6.

A breather hose 8 is attached to the upper part of the crankcase 7 of this engine 3.
extends into the body frame 9 of the motorcycle, and its outlet opening 10 is also arranged within the body frame 9.

Further, in a second conventional example of the breather device shown in FIG. 4, a breather hose 13 is attached to the upper part of the crankcase 12 of the engine 11, and this breather hose 13 extends downward from the outside of the crankcase 12. An outlet opening 14 of the breather hose 13 leads to the lower part of the engine 11.

In addition, the code|symbol 15 shows a cylinder.

(Problems to be Solved by the Invention) In the second conventional example shown in FIG. 4, the outlet opening 14 of the breather hose 13 may become clogged with mud, snow, etc. while the vehicle is running. Especially in the case of snow, once melted snow may refreeze. In such a case, crankcase 1
Since the inside of the crankcase 12 is no longer communicated with the outside air, the pressure inside the crankcase 12 increases, and in the unlikely event that the oil seal comes off, there is a risk that problems may occur.

Further, in this second conventional example, when the warmed engine 11 is splashed with water while the vehicle is running, the temperature inside the engine 11 decreases, and water flows into the crankcase 12 from the outlet opening 14 of the breather hose 13. There is also a risk of intrusion.

On the other hand, in the first conventional example shown in FIG.
is disposed within the vehicle body frame 9, so the engine 3
At the same time as or after being mounted on the vehicle body frame 9, the breather hose 8 must be routed within the vehicle body frame 9, making the installation work of the breather hose 8 complicated.

The present invention was developed in consideration of the above circumstances, and an object of the present invention is to provide a breather device that prevents clogging of a breather hose and that can be easily installed.

[Structure of the invention]

(Means for Solving the Problems) In the present invention, a breather hose is attached to the crankcase of an engine to guide blow gas, etc. in the crankcase to the outside, and an outlet opening of the breather hose is connected to the crankcase. It is characterized by being placed between the crankcase and the cover that covers the crankcase.

(Function) It is difficult for mud, sand, or snow in cold regions to enter the space surrounded by the crankcase and cover.

Therefore, since the outlet opening of the breather hose is disposed within this space, it is possible to prevent the breather hose from being clogged with mud, sand, snow, or the like.

Further, since this breather hose can be attached at the same time as the engine is assembled, there is no need to make equal adjustments to the breather hose when the engine is assembled to the vehicle body, and the breather hose can be easily attached.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a side view showing an engine to which an embodiment of the breather device according to the present invention is applied, and FIG. 1 is a diagram showing how the breather hose is attached to the engine shown in FIG.

As shown in FIG. 2, an engine 21 mounted on the body frame of a motorcycle includes a crankcase 22 that houses a crankshaft (not shown) and a reduction gear, and a cylinder 23 installed in the crankcase 22. It is composed of

The cylinder 23 includes a cylinder block 24, a cylinder head 25, and a head cover 26, and a cylinder sleeve (not shown) attached to the cylinder block 24.
A piston (not shown) is disposed therein so as to be able to reciprocate.

This reciprocating motion of the piston is converted into rotational motion of the crankshaft, and the rotational force of the crankshaft is transmitted to the drive sprocket 27 via the reduction gear. A drive chain 28 shown in FIG. 1 is wound around this drive sprocket 27, and the rear wheel is rotationally driven via this drive chain 28.

Now, a breather union 29 is installed above the rear part of the crankcase 22 so as to protrude to the outside, and a breather hose 30 is connected to this breather union 29. Here, both sides of the crankcase 22 in the left-right direction of the vehicle are covered with a magnet cover 31 shown in FIG. 2 and a clutch cover (not shown), respectively.

Further, a sprocket cover 32 that covers the drive sprocket 27 is attached to the crankcase 22 behind the magnet cover 31.

Note that the reference numeral 37 in FIG. 2 indicates a gear shift lever.

The breather hose 30 is curved as shown in FIGS. 1 and 2 to reach the space between the crankcase 22 and the sprocket cover 32, and is fixed to the crankcase 22 by a clamp 35. Therefore, the outlet opening 36 of the breather hose 30 also exists within the space surrounded by the crankcase 22 and the sprocket cover 32.

The breather hose 30 prevents a rise in pressure within the crankcase 22 by discharging blow-by gas leaked into the crankcase 22 from the gap between the piston and the cylinder sleeve to the outside due to the reciprocating movement of the piston. On the other hand, the crankcase 22 and sprocket cover 3
Mud, snow, etc. do not enter into the space between 2 and 2 while the motorcycle is running.

Therefore, since the outlet opening 36 of the breather hose 30 is disposed in the space between the crankcase 22 and the sprocket cover 32, the outlet opening 36 will not be clogged with mud, snow, or the like. In particular, if the snow becomes clogged, the risk of the snow freezing once it has melted can be avoided. Since the breather hose 30 can be prevented from being clogged in this way, various problems (such as oil seal failure) caused by the increase in pressure within the crankcase 22 can be prevented.

Further, since water does not splash up in the space surrounded by the crankcase 22 and the sprocket cover 32 while the vehicle is running, it is also possible to prevent water from entering into the crankcase 22 from the outlet opening 36 of the breather hose 30. .

Furthermore, the breather hose 30 can be attached to the crankcase 22 using the clamp 35 when the engine 21 is assembled, so there is no need to route the breather hose 30 inside the vehicle frame when the engine 21 is mounted on the vehicle body frame. do not have. As a result, the workability of attaching the breather hose 30 can be improved.

In the above embodiment, the outlet opening 36 of the breather hose 30 is present in the space surrounded by the crankcase 22 and the sprocket cover 32, but Alternatively, it may exist in a space surrounded by the crankcase 22 and the clutch cover, or in a chain case disposed behind the sprocket cover 32.

〔Effect of the invention〕

As described above, according to the breather device according to the present invention,
Since the outlet opening of the breather hose is disposed between the crankcase and the cover that covers the crankcase, clogging of the breather hose can be prevented and the breather hose can be easily attached.

3 is a side view showing a motorcycle equipped with a first conventional example of a breather device, and FIG. 4 is a side view showing an engine to which a second conventional example of a breather device is applied.

21...Engine, 22...Crankcase, 29
... Breather Union, 30 ... Breather Hose, 3
2... Sprocket cover, 35... Clamp, 3
6...Exit opening.

Applicant's agent Hisashi Hatano

[Brief explanation of drawings]

Claims (1)

[Claims] A breather hose that guides blow-by gas, etc. inside the crankcase to the outside is attached to the crankcase of the engine, and the outlet opening of the breather hose is arranged between the crankcase and a cover that covers the crankcase. A breather device featuring: