JP2000130144A - Breather device of vertical engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overflow of oil from breather chambers by integrally forming the breather chambers on a side part of a cylinder block by stretching the chambers over both of a cylinder and a cylinder head. SOLUTION: A cylinder block 17 extends a cylindrical cylinder 19 in a direction orthogonally crossed with a crank shaft 10 toward the rear side and a cylinder head 20 is arranged at a rear end of this cylinder 19. On a side of the cylinder block 17, breather chambers 49C, 49H which stretch over both of the cylinder 19 and the cylinder head 20 and constitutes a breather device 48 provided with an engine 3 are integrally formed. As a result, a valve device such as a reed valve can be arranged on a coupling surface of the cylinder 19 and the cylinder head 20. By this valve device, blow overflow of oil from the breather chambers 49C, 49H when an outboard engine is transversely installed can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a breather device for a vertical engine.

[0002]

2. Description of the Related Art In an engine, a small amount of gas with pressure generated in a combustion chamber leaks into a crankcase through a gap between a piston and a cylinder bore. Further, since the pressure of the gas in the crankcase constantly fluctuates with the sliding of the piston, when the crankcase is sealed, the pressure of the gas in the crankcase, so-called blow-by gas, hinders the movement of the piston. . This allows blow-by gas in the crankcase to escape to the outside,
It is necessary to provide a means for separating oil mixed in the blow-by gas, that is, a breather device.

[0003] As a conventional example of a breather device of a vertical engine used for an outboard motor or the like, for example, Japanese Unexamined Patent Publication No.
As disclosed in Japanese Patent Application Laid-Open No. 119394/1992, there is a configuration in which a breather chamber is formed separately above a cylinder head cover of an engine to form a breather device.

[0004]

However, the outboard motor is tilted up when the boat is moored, or is placed almost horizontally when it is removed from the boat and stored. Therefore, a breather chamber is provided above the cylinder head cover. The oil stored in the breather chamber may blow out.

[0005] Further, if the breather chamber is provided separately, the cost is increased and the size of the engine is increased.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide a vertical engine breather device which reduces costs and downsizes the engine.

Another object of the present invention is to provide a breather apparatus for a vertical engine which prevents oil from spilling out of a breather chamber.

[0008]

According to the present invention, there is provided a breather apparatus for a vertical engine, comprising: a cylinder block comprising a cylinder and a cylinder head; The breather chamber is formed integrally on both sides of the cylinder block over both the cylinder and the cylinder head.

According to another aspect of the present invention, a valve is provided in an opening formed in a mating surface of the breather chamber formed on the cylinder head side with the cylinder. A device is provided.

Further, in order to solve the above-mentioned problems,
According to a third aspect of the present invention, the oil reservoir is formed on the bottom surface of the breather chamber.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a right side view showing an example of an outboard motor to which a vertical engine according to the present invention is applied. As shown in FIG. 1, this outboard motor 1 has a box-shaped engine cover 2 at the top, and a vertical (vertical) engine 3 is housed inside. A steering handle 4 extends forward from the front of the engine cover 2 (the right side in FIG. 1), and a throttle grip 5 for adjusting the engine output is provided at its tip.

A shaft housing 6 is provided below the engine cover 2.
The gear case 7 is provided at the lower part of the vehicle. A propeller shaft 8 is rotatably supported inside the gear case 7, and a propeller 9 is provided at a rear end thereof.

FIG. 2 is a longitudinal sectional view of the engine 3 of the outboard motor 1, and FIG. 3 is a sectional view taken along the line III-III of FIG. FIG. 4 is a view taken in the direction of the arrow IV in FIG. As shown in FIG. 1 and FIG. 2, the crankshaft 10 is installed vertically in the engine 3 so as to be substantially vertical (vertical).
Is provided.

A drive shaft 11 connected to the lower end of the crankshaft 10 extends downward in the shaft housing 6, and the lower end of the drive shaft 11 is connected to the propeller shaft 8 via a bevel gear 12. The output of the engine 3 is transmitted to the propeller shaft 8 via the drive shaft 11 and the bevel gear 12, and rotates the propeller 9.

The upper portion of the shaft housing 6 is rotatably supported by a rotation support portion 14 of a clamp bracket 13, and the clamp bracket 13 is fixed to a transom of a ship (not shown). That is, the outboard motor 1 is rotatable about 360 ° with respect to the boat, and the steering of the boat can be performed by swinging the steering handle 4 in the horizontal direction to change the direction of the entire outboard motor 1. It is configured as follows.

The engine cover 2 is, for example, vertically splittable, and comprises a lower cover 2a fixed to the lower portion of the engine, and an upper cover 2b detachably mounted on the lower cover 2a. You. The steering handle 4 is provided integrally with the lower cover 2a.

On the other hand, the engine 3 used in this embodiment
Is a single-cylinder engine of, for example, a four-cycle OHV type. As shown in FIGS. 2 and 3, the engine housing 15 is divided into two parts in the front-rear direction (the left-right direction in FIGS. 2 and 3) and the front side (the right side in the figures) ) And the rear (left side in the figure) cylinder block 17 are joined together. The engine housing 15 is fixed on an extension case 18 provided at the upper end of the shaft housing 6.

The cylinder block 17 includes a cylindrical cylinder 19 extending rearward (leftward in the figure) in a direction perpendicular to the crankshaft 10, and a cylinder 1.
9 and a cylinder head 20 disposed at the rear end of the cylinder cover 20.
Blocked by. A fuel tank 22 is disposed above the cylinder block 17, and an oil pan 23 is formed below the cylinder block 17 so as to extend over both the cylinder 19 and the cylinder head 20.

A cylinder bore 19 is provided inside the cylinder 19.
a, and a combustion chamber 24 is formed in the cylinder head 20 so as to match the cylinder bore 19a.
The ignition plug 25 is connected to the combustion chamber 24 from outside.

The crankshaft 10 is supported at a substantially intermediate portion by a pair of bearings 26, in this embodiment, ball bearings. A pair of webs 27 are formed on the crankshaft 10 between the two bearings 26 so as to be separated from each other in the axial direction, and a crankpin 28 is eccentrically provided therebetween.

On the other hand, a piston 29 is slidably inserted into the cylinder bore 19a. The piston pin 30 of the piston 29 and the crankpin 28 of the crankshaft 10 are connected by a connecting rod 31, whereby the reciprocating motion of the piston 29 in the cylinder bore 19 a is converted into the rotational motion of the crankshaft 10. At the upper end of the crankshaft 10, a flywheel magneto device 32 for power generation and a rope recoil type engine start device 33 are provided.

In the cylinder head 20, an intake port 34 and an exhaust port 35 connected to the combustion chamber 24 are formed.
In the cylinder head 20, an intake valve 36 and an exhaust valve 37 for opening and closing both ports 34 and 35 are arranged.

As shown in FIG. 2, the exhaust port 35 is connected to the extension case 18, and is configured to exhaust the exhaust gas from the extension case 18 to the outside through the shaft housing 6. As shown in FIGS. 3 and 4, a carburetor 38 is arranged on the side of the cylinder block 17 and connected to the intake port 34, and a silencer 39 is connected to the upstream side of the carburetor 38.

On the other hand, as shown in FIG. 3, a camshaft 40 is arranged on the side of the crankshaft 10 in parallel with the crankshaft 10. A timing drive gear 41 is provided integrally or integrally with the crankshaft 10, and a timing driven gear 42 is provided integrally or integrally with the camshaft 40, and the two timing gears 41 and 42 are meshed and connected. As a result, the torque of the crankshaft 10 is transmitted to the camshaft 40. The two timing gears 41 and 42 are housed in a gear chamber 43 in the engine housing 15 formed by joining the crankcase 16 and the cylinder block 17. The gear chamber 43 communicates with the oil pan 23 and stores oil together with the oil pan 23.

A cam 44 is provided on the camshaft 40. When the camshaft 40 rotates, the profile of the cam 44 moves in the axial direction of a push rod 46 in a push rod passage 45 formed on the cylinder 19 side. The rocker arm 47 provided in the cylinder head 20 is caused to swing back and forth. The rocking motion of the rocker arm 47 causes the intake valve 36 and the exhaust valve 37 in the cylinder head 20 to open and close.

The engine 3 of the outboard motor 1 is provided with a breather device 48. The breather chambers 49C and 49H constituting the breather device 48 are integrally formed on the side of the cylinder block 17 so as to extend over both the cylinder 19 and the cylinder head 20.

FIG. 5 is a view taken in the direction of the arrow V in FIG. 2, and is a view in which the cylinder head 20 is viewed from the mating surface side with the cylinder 19. FIG. 6 is a view taken in the direction of arrow VI in FIG. 2, and is a view of the cylinder 19 viewed from the mating surface side with the cylinder head 20. Further, FIG. 7 shows VII-VII of FIG.
FIG. 8 is a sectional view taken along the line, and FIG.
It is sectional drawing which follows the I line.

As shown in FIG.
And a breather chamber 49H formed on the cylinder head 20 side. As shown in FIGS. 5 and 7, a breather chamber 4 formed on the cylinder head 20 side is formed.
9H, opening 5 formed in the mating surface with cylinder 19
0 is provided with a reed valve 51 which is a valve device. The reed valve 51 is set so that blow-by gas can pass only from the breather chamber 49H on the cylinder head 20 side to the breather chamber 49C on the cylinder 19 side.

As shown in FIGS. 6 and 8, the cylinder 1
An oil sump groove 52 is formed on the bottom surface of the breather chamber 49C formed on the 9th side. A breather oil outlet 53 is formed in the sump groove 52, and one end of a breather oil pipe 54 is connected to the breather oil outlet 53. The other end of the breather oil pipe 54 is connected to a union 55 provided in the gear chamber 43 as shown in FIGS.

On the other hand, a blow-by gas discharge port 56 is formed on the upper surface of the breather chamber 49C formed on the cylinder 19 side, and one end of a breather hose 57 is connected to the blow-by gas discharge port 56. The other end of the breather hose 57 is connected to the silencer 39 as shown in FIGS.

Next, the operation of the present embodiment will be described.

The blow-by gas generated in the combustion chamber 24 and leaked into the engine housing 15 through the space between the cylinder bore 19 and the piston 29 passes through an oil return passage (not shown), a push rod passage 45, and the like.
Guided within 0. The blow-by gas guided into the cylinder head 20 is guided into a breather chamber 49H formed on the cylinder head 20 side of breather chambers 49C and 49H formed over both the cylinder 19 and the cylinder head 20.

The breather chamber 49H on the cylinder head 20 side
The blow-by gas guided to the inside is guided to the breather chamber 49C formed on the cylinder 19 side via the reed valve 51, and the oil component in the blow-by gas is separated by the oil sump groove 52 inside this. The blow-by gas from which the oil component has been separated is led from the blow-by gas outlet 56 through the breather hose 57 to the silencer 39, and is again led to the combustion chamber 24 and burned.

On the other hand, the breather chamber 49C on the cylinder 19 side
The oil component in the blow-by gas separated inside is introduced into the gear chamber 43 from the breather oil discharge port 53, lubricates the timing gears 41 and 42, and then returned to the oil pan 23.

Since the breather chambers 49C and 49H are integrally formed on the side of the cylinder block 17, the cost can be reduced and the size of the engine 3 can be reduced as compared with the conventional case where the breather chamber is provided separately. Will be possible.

Further, by forming the breather chambers 49C and 49H over both the cylinder 19 and the cylinder head 20, a valve device such as a reed valve 51 can be arranged on the mating surface between the cylinder 19 and the cylinder head 20. The valve device 51 prevents oil from spilling out of the breather chambers 49C and 49H when the outboard motor 1 is placed horizontally, for example.

By forming the oil sump groove 52 on the bottom of the breather chamber 49C, separation of the oil mixed in the blow-by gas becomes easy.

In the above-described embodiment, the engine 3 used in the outboard motor 1 as a vertical engine has been described. However, if the crankshaft 10 is vertically arranged in the engine 3, a lawn mower or It is also applicable to general-purpose engines for generators and the like.

[0040]

As described above, according to the breather apparatus for a vertical engine according to the present invention, in an engine having a cylinder block composed of a cylinder and a cylinder head, a breather chamber is provided at the side of the cylinder block. Is formed integrally over both the cylinder and the cylinder head, so that cost reduction and downsizing of the engine can be achieved.

Further, since the valve device is provided at the opening of the breather chamber formed on the cylinder head side at the mating surface with the cylinder, it is possible to prevent oil from spilling from the breather chamber.

Further, since the oil collecting groove is formed on the bottom surface of the breather chamber, the oil component in the blow-by gas can be easily separated.

[Brief description of the drawings]

FIG. 1 is a right side view of an outboard motor showing an embodiment of a breather device for a vertical engine according to the present invention.

FIG. 2 is a longitudinal sectional view of a vertical engine portion of the outboard motor.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a view taken in the direction of an arrow IV in FIG. 2;

FIG. 5 is a view taken in the direction of the arrow V in FIG. 2;

FIG. 6 is a view taken in the direction of arrow VI in FIG. 2;

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 5;

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outboard motor 3 vertical engine 10 crankshaft 16 crankcase 17 cylinder block 19 cylinder 20 cylinder head 23 oil pan 48 breather device 49C, 49H breather chamber 50 breather chamber opening 51 reed valve (valve device) 52 oil reservoir groove

Claims (3)

[Claims] In an engine having a cylinder block composed of a cylinder and a cylinder head, breather chambers (49C, 49C) are provided on the side of the cylinder block (17).
A breather device for a vertical engine, wherein H is integrally formed over both the cylinder 19 and the cylinder head 20. 2. A valve device 51 is provided in an opening 50 formed in a mating surface of the breather chamber 49H formed on the cylinder head 20 side with the cylinder 19.
The breather device of the vertical type engine described in the above. 3. The breather device for a vertical engine according to claim 1, wherein an oil sump groove 52 is formed in a bottom surface of the breather chamber 49C.