JP2002276321A - Lubricating device for 4-cycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly discharge air from oil reservoir chamber, by surely opening return oil passages at a side immersed in an oil regardless of a using condition. SOLUTION: One end in an extending direction is made open inside a valve chamber, and the pair of return oil passages 84, 84' arranged to both sides of a shaft center of a crankshaft are provided. In opening parts 84D, 84D' at a side of the oil reservoir chamber in the return oil passages 84, 84', when the 4-cycle engine lies sideways with the shaft center of the crankshaft being as a center, the one opening part is arranged above an oil level of the oil reservoir chamber, the other opening part is arranged below the oil level, and the opening parts 84D, 84D' are arranged to be inclined such that they come close to each other toward the oil level. Check valves 100 provided with spherical bodies capable of sealing the return oil passages are respectively provided inside the opening parts 84D, 84D'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a four-stroke engine, and more particularly, to a lubricating device and a portable power sprayer in which a tilting position is one of working positions. The present invention relates to a lubricating device for a small four-cycle engine.

[0002]

2. Description of the Related Art In general, an engine which is a driving source of a working machine which is carried or carried by a worker himself, such as a portable brush cutter (trimmer) or a backpack type power sprayer for plants, is used. There is a need for stable operation even when the working machine is tilted. A two-stroke engine, which is a type of engine, includes a mechanism for lubricating each movable part by using a negative pressure generated when a piston rises to suck lubricating oil and fuel into the engine. In relation, a structure that can be used at any angle can be easily realized. For this reason, two-stroke engines are widely used in the portable work machines. On the other hand, a four-stroke engine, which is another type of engine, can be manufactured in a small and light weight due to advances in design and processing techniques. And a structure in which the movable parts are lubricated by jumping up the oil from the position or pumping up the oil with the pump, is basically used in an upright state. In other words, such a lubrication mechanism was inferior to a two-stroke engine. However, the two-cycle engine has problems such as a large amount of hydrocarbons in the exhaust gas and a large noise. For this reason, in recent years, it has been demanded to use a four-stroke engine having good exhaust gas characteristics and low noise for a portable work machine from the viewpoint of purifying exhaust gas and preventing deterioration of a working environment. Therefore, the present applicant has previously proposed a lubricating device for a four-stroke engine that utilizes the fact that the pressure in the crank chamber changes according to the elevating operation of the piston (for example, Japanese Patent Application Laid-Open No. 10-28801).
No. 9). In this proposal, after completely shutting off the oil chamber and the crank chamber, the crank chamber and the oil chamber are communicated from the oil chamber to a part of the rotation trajectory of the crankshaft, and the negative pressure of the crank chamber is reduced. Intermittent oil feeding means for sucking oil from the oil storage chamber and sending it to the crank chamber, further connects the crank chamber with the valve operating chamber equipped with the cam mechanism and the arrangement part of the valve drive mechanism, and when the piston descends Utilizing the generated positive pressure in the crank chamber, the oil mist stirred in the crank chamber is pressure-fed. On the other hand, the blow-by gas containing oil mist sent into the valve operating chamber tends to be negative pressure in the oil reservoir, that is, the negative pressure in the crank chamber generated when the piston rises acts on the oil reservoir. It is to be collected indoors.

[0003]

However, after the engine is started, including the above-described structure, the pressure in the oil reservoir increases as the cylinder temperature increases. For this reason, even if an attempt is made to recover oil from the valve operating chamber into the oil storage chamber, it may not be possible to recover the oil satisfactorily due to insufficient negative pressure in the oil storage chamber. As a result, the oil is maintained in an excessive state in the valve operating chamber, and there is a possibility that the lubricating oil for other parts becomes insufficient.

[0004] As a structure for collecting the oil that is excessively accumulated in the valve operating chamber, return oil paths for communicating the valve operating chamber and the oil storing chamber are provided in parallel in pairs, and are provided at the opening on the oil storing chamber side. It is conceivable that a check valve provided with a sphere capable of closing the opening when the engine is tilted is provided so that the oil in the oil reservoir does not flow backward when the engine tilts.

[0005] The sphere used for the check valve moves in the direction of gravity. However, depending on the condition of use of the engine, the opening of the return oil passage may be completely closed. For example, when the engine is turned sideways around the axis of the crankshaft, one of the return oil passages opened to the oil reservoir is located below the oil surface, and the opening is located in the oil. Will do. At this time, the sphere of the check valve in the return oil passage hardly receives a force in the gravitational direction, and the entire opening is closed by the suction pressure of the return oil passage. For this reason, air cannot be discharged from the oil reservoir and smooth lubrication cannot be performed.

SUMMARY OF THE INVENTION In view of the above-described problems in the return oil passage using the check valve, the object of the present invention is to reliably open the return oil passage on the side that is not immersed in oil, regardless of the operating condition of the engine. Accordingly, it is an object of the present invention to provide a four-stroke engine lubricating device capable of smoothly discharging air from an oil reservoir.

[0007]

According to the first aspect of the present invention,
A valve operating chamber (34) accommodating the crank chamber (16) and intake and exhaust valve mechanisms from an oil sump chamber (18) provided near a crank chamber (16) on which a crank shaft (20) is supported. ), Lubricates each part and circulates the oil. In a lubricating device for a four-stroke engine, one end in the extension direction is opened in the valve chamber (34), and the other end in the extension direction is the oil sump. A pair of return oil passages (84, 84 ') which are opened in the chamber (18) and arranged on both sides of the axis of the crankshaft (20) are provided.
4 ′), the opening (84) on the oil sump (18) side.
D, 84D ') are positioned one above the oil level of the oil sump chamber (18) and the other below the oil level when the four-stroke engine is in a downside position around the axis of the crankshaft (20). And a check valve (100) provided with a sphere which is provided so as to be inclined toward the oil level so as to approach each other and can close the return oil passage. It is characterized by:

According to a second aspect of the present invention, a crankshaft (2
0) is fed from an oil reservoir (18) provided near a crank chamber (16) that supports the crank chamber (16) to a valve operating chamber (34) that houses the intake and exhaust valve mechanisms. In a lubricating device for a four-stroke engine that lubricates various parts by oiling and circulates oil, one end in the extension direction is opened in the valve operating chamber (34), and the other end in the extension direction is the oil sump (18). ) And the crankshaft (20)
A pair of return oil passages (84, 8)
4 ′), and the openings (84D, 84D ′) on the oil reservoir (18) side in the return oil passages (84, 84 ′) are
When the four-stroke engine is in an upside down state around the axis of the crankshaft (20), one is disposed above the oil level of the oil reservoir (18), and the other is positioned below the oil level and parallel to each other. A check valve (10) having a stepped portion (84P, 84P ') formed on the inner surface on the oil surface side and having a sphere capable of closing the oil passage inside.
0) is provided.

[0009]

According to the first aspect of the present invention, when the four-stroke engine is in the sideways position, the upper part of the oil reservoir (18) in the opening (84D, 84D ') provided in the pair of return oil passages. One and the other are arranged so as to be located below the oil level and are inclined so as to approach each other toward the oil level, so that in one opening located at the upper part of the oil level The sphere separates from the return oil passage by gravity, and can move to a position where the sphere blocks the return oil passage by gravity at the other opening below the oil level. As a result, a state in which one of the return oil passages is not blocked is maintained,
Since the other of the return oil passages, that is, the return oil passage below the oil level, is closed by the check valve, the air can be smoothly discharged from the oil reservoir (18).

According to the second aspect of the present invention, when the four-cycle engine is in a sideways position, the openings (84D, 84D,
84D '), one is located above the oil level of the oil reservoir (18), and the other is located below the oil level and arranged in parallel with each other, and a stepped step is formed on the inner surface on the oil level side. Part (84
P, 84P ′) is formed, and in the opening below the oil level, the sphere of the check valve (100) can be positioned in the stepped portion by the gravity to close the return oil passage, but the opening on the oil level is closed. Since it is possible to maintain a state in which no oil is released, air can be smoothly discharged from the oil reservoir (18).

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are schematic diagrams for explaining a lubrication path of a four-cycle engine using a lubrication device according to an embodiment of the present invention. In particular, FIG. 1 shows the case where the piston is located at the top dead center.
Indicates a case where the piston is located at the bottom dead center. The four-stroke engine shown in FIGS. 1 and 2 is provided with the configuration disclosed in Japanese Patent Application Laid-Open No. 10-288019 corresponding to the earlier application of the present application as a main part, and the configuration is described below. Later, the present embodiment will be described.

As shown in FIG. 1, a four-cycle engine 1
Has an air cleaner 2 and a carburetor 4 on the left side, and an exhaust muffler 6 on the right side.
The crankcase 16 includes a cylinder block 12 in which the cylinder head 10 is integrated and a crankcase 14, and an oil reservoir 18 provided near the lower portion of the crankcase 14. The oil reservoir 18 is partitioned from the crankcase 14 to form a closed space as a whole.

In FIG. 1, the crankcase 14 is provided with a suction portion 40 and a one-way valve 70, which will be described later. The one-way valve 70 can be opened and closed in response to a change in pressure in the crank chamber 16. When there is no change in pressure, the oil reservoir 18 is closed so that no oil leaks outside even if the oil reservoir 18 is in any inclined state.

Cylinder block 12 and crankcase 1
As shown in FIG. 1, a crankshaft 20 having an axial center provided in a horizontal direction is rotatably supported by the crankshaft 4. A piston 24 connected to a crankpin of the crankshaft 20 via a connecting rod is slidably inserted in a cylinder 12A provided inside the cylinder block 12.

In FIG. 1, on the upper wall of the cylinder 12A,
An intake port and an exhaust port are formed to communicate with the carburetor 4 and the exhaust muffler 6, respectively, and an intake valve 27 and an exhaust valve 28 for opening and closing the ports are arranged in these ports. As shown in FIG. 1, a valve driving unit 30 for driving these valves is provided with a valve driving gear 3.
6. It is composed of components such as a cam gear 37 and a rocker arm (not shown). These valve driving units 30
Of the valve drive gear 36, the cam gear 3
Numeral 7 is provided in a communication passage 32 formed on the side of the cylinder block 12 and the crankcase 14 so as to communicate the valve operating chamber 34 formed in the head of the cylinder block 12 with the crank chamber 16. Have been.

Between the crank chamber 16 and the oil reservoir 18,
The suction section 40, the passage 44, and the intermittent oil supply section 46 are provided as first oil supply means. In FIG.
Is constituted by a tube body 44 which can be easily bent by an elastic material such as rubber, and a weight 43 provided at the tip thereof. That is, the weight 43 can always move vertically downward due to its gravity.
Thus, even when the oil reservoir 18 is inclined, the tip can be immersed below the oil level of the oil. The other end of the suction portion 40 communicates with a passage 44A formed in the crankcase 14, and the passage 44A faces the outer peripheral surface of the crankshaft 20 and forms an arc-shaped opening in this portion. are doing.

In FIG. 1, the intermittent oil supply section 46 on the crankshaft 20 side has a passage T1 formed in the vicinity of the center of the crankshaft 20 from the crank chamber 16 side with a predetermined inner diameter without penetrating outside, A passage T2 is formed continuously from the passage T1 toward the radial direction of the crankshaft 20. The passage T2 is connected to the crankshaft 20 in response to the negative pressure in the crank chamber 16 caused by the rise of the piston 24.
Can be communicated with the passage 44A of the crankcase 14 within the rotation angle of, that is, the so-called passage 44A of the crankcase 14 during the so-called full rotation of the crankshaft 20. For this reason, when the piston 24 rises, the suction unit 40, the passage 44 </ b> A and the intermittent oil supply unit 46 use the negative pressure generated in the crank chamber 16.
Is communicated, oil is sucked from the oil reservoir 18 and sent to the crank chamber 16 side.

In FIG. 1, the crank chamber 16 is provided with a stirrer that stirs oil supplied by the intermittent oil feeder 46 to form an oil mist. The stirrer is mainly fixed to the crankshaft 20. It consists of a crank web.

1 and 2, a one-way valve 70 is provided between the crank chamber 16 and the communication passage 32 as a second oil feed means. The one-way valve 70 opens the valve hole formed in the lower part of the crankcase 14 and opens the valve hole when the crank chamber 16 becomes positive pressure as the piston 24 moves up and down. It is constituted by a valve plate 72 that closes the valve hole when it becomes.

In FIG. 2, a breather pipe 80 is provided at an upper portion of the cylinder block 12. One end of the breather pipe 80 is connected to the inside of the valve operating chamber 34 by an opening 82, and the other end is connected to an air cleaner. Have been. Valve train room 3
4 are provided with return oil passages 84 and 84 ′. One end of each of these return oil passages 84 and 84 ′ is open to the valve operating chamber 34, and the other end is separately arranged in the oil reservoir 18. Have been. The return oil passages 84 and 84 ′ are disposed on both sides of the axis of the crankshaft 20.

In such a configuration, as shown in FIG.
When the valve operating chamber 34 of the engine 1 is positioned upward, that is, in a so-called upright state, when the piston 24 is not in the elevating operation, the lubrication in the crank chamber 16, the oil reservoir 18 and the valve operating chamber 34 is performed. Suitable amount of oil.

When the engine 1 is started, a pressure change occurs in the crank chamber 16 due to the raising / lowering operation of the piston 24. When the piston 24 rises, the pressure in the crank chamber 16 is reduced to a negative pressure. It becomes positive pressure tendency.

When the pressure in the crank chamber 16 becomes negative, a pressure difference is generated between the crank chamber 16 and the oil reservoir 18, and the crankshaft rotates so as to communicate with the oil reservoir 18 when the piston 24 rises. 20 (see FIG. 1).
The oil stored in the oil storage chamber 18 is sent to the crank chamber 16 through the passages T1 and T2 of FIG. 1 and the suction section 40 (the state shown by the solid arrow in FIG. 1). In FIGS. 1 and 2, solid arrows indicate the flow direction of the oil, and broken arrows indicate the flow direction of the blow-by gas.

The oil sent to the crank chamber 16 is transmitted to the crank web, scatters from the end to the inner wall of the crank chamber 16, and a part of the oil mist is formed. The mist oil lubricates the crankshaft 20, the piston 24, and the components in the crankcase 16.

When the piston 24 shown in FIG. 2 descends, the pressure in the crank chamber 16 becomes positive, and a differential pressure is generated between the crank chamber 16 and the oil reservoir 18. In this case, the valve plate 72 of the one-way valve 70
Opens the valve hole, and sends the oil mist stored in the crank chamber 16 and the cylinder 12A together with the pressurized air from the crank chamber 16 to the communication passage 32. The oil mist sent to the communication passage 32 is pressure-fed to the valve operating chamber 34 by the positive pressure and lubricates the components of the valve drive unit 30. The oil mist that has lubricated the components of the valve drive unit 30 reaches the valve operating chamber 34 and is separated into oil and air. The separated oil passes through the return passages 84 and 84 'to the oil reservoir 18
Will be collected on the side. The separated air is released from the opening 82 into the air cleaner 2 via the breather tube 80. Note that oil mist is mixed in this air.

Next, when the engine 1 is used in a so-called inverted state, the suction portion 40 in the oil storage chamber 18 is stored in the oil stored by the movement of the weight 43 located at the tip thereof in the direction of gravity. Since it is immersed, oil is supplied to each lubricating part by utilizing a pressure change due to the elevating operation of the piston 24. Such supply of oil is also performed when the engine 1 is in an inclined state.

Referring to FIG. 1, the detailed structure of one of two return oil passages 84 and 84 'having one end disposed in the valve operating chamber 34 and having substantially the same structure will be described.
The other end is opened at the upper part of the oil reservoir 18, but the return oil passage 84 has a bypass structure in the middle. The description of the other (84 ') of the return oil passage 84 is omitted, but has the same configuration as that of the return oil passage 84. In other words, the oil suction passage 90 forming the bypass structure includes the branch passage 84A branched from the return oil passage 84 and the opening 2 located immediately below the skirt portion 24A of the piston 24 at the top dead center position.
4B, and a passage 84C connecting the branch passage 84A and the passage 84B. The opening 24B located immediately below the skirt portion 24A is
Since it is drilled in the skirt portion 24A and communicates with the inside of the cylinder 12A, when communicating with the passage 84B, the passage 84B
Communicates with the inside of the cylinder 12A.

On the other hand, a check valve 100 having a sphere which is received by a seat plate (not shown) and maintained in a state of not falling off is provided in an opening 84D located above the oil reservoir 18 in the return oil passage 84. Is provided. In the present embodiment, the sphere forming the check valve 100 is made of a steel ball, but it is a matter of course that the present invention is not limited to this as long as the material is oil-resistant.

In FIG. 1, a recirculation portion 110 communicating with the oil reservoir 18 is formed on the lower surface wall of the crankcase 14 in the vicinity of the communication passage 32 communicating the crank chamber 16 with the valve operating chamber 34. In this embodiment, the air cleaner 2
At the position where the breather pipe 80 communicates with the
A is provided from the breather chamber 2A to the breather chamber 2A and an oil-absorbing opening (indicated by a reference numeral 24B 'for convenience) formed immediately below the skirt portion 24A of the piston 24 at the top dead center position. The communication pipe 120 is extended, and the oil component in the blow-by gas collected in the breather pipe 80 is separated into gas and liquid by the oil separator 120A and supplied to the cylinder 12A from the oil supply opening 24B '.

The opening 84 in which the check valve 100 is provided
D and 84D 'have the configuration shown in FIG. In addition,
FIG. 3 shows, for convenience, the openings 84D, 8D in a state where the engine is turned down so that the carburetor side is the lower side in FIG.
The arrangement relationship between the 4D's is schematically shown with the oil surface as a boundary, and the actual positions are separated as shown in FIGS. In FIG. 3, when the engine is turned down around the axis of the crankshaft 20, one of the openings 84D and 84D 'is located above the oil level in the oil reservoir 18 and the other is the other. Part 84D '
Are arranged below the oil level. Each opening 8
4D and 84D 'are inclined toward the oil surface in a state of approaching each other (state in which an angle indicated by reference numeral θ in FIG. 3 is provided).
The sphere of the check valve 100 provided inside can be moved by gravity. Note that FIG.
Reference numeral 84F indicates a seat plate that prevents the sphere of the check valve 100 from falling off. As shown in FIG. 2, if check valves 200, 200 that can only pass upward are provided in the middle of the return oil passages 84, 84 ′, the lubricating oil circulation efficiency is further improved.

Since the present embodiment has the above configuration,
As described above, when the piston 24 rises when the engine 1 is upright, the crank chamber 16 and the oil reservoir 1
8 and the crank chamber 16 tends to be negative pressure. Therefore, the oil is stored in the oil reservoir 18 via the passages T1 and T2 of the intermittent oil supply unit 46 and the suction unit 40 provided on the crankshaft 20 which rotates so as to communicate with the oil reservoir 18 when the piston 24 rises. The oil that has been removed
Sent to the side.

On the other hand, when the piston 24 reaches the top dead center position, the oil supply passage 84B formed in a part of the return oil passage 84 from the valve operating chamber 34 becomes the skirt portion 2 of the piston 24.
The cylinder 1 communicates with the opening 24B located immediately below the cylinder 4A.
Communicate with 2A. For this reason, when the crank chamber 16 has a negative pressure tendency, the oil in the valve operating chamber 34 is taken into the oil supply path by the negative pressure which becomes strongest at the top dead center position of the piston 24, and as shown in FIG. As indicated by the arrows,
It is sucked into the cylinder 12A through the opening 24B.
Therefore, the oil mist sent into the valve operating chamber 34
The oil is sucked into the cylinder 12A through the return oil passage 84 by the negative pressure in the crank chamber 16 and the other oil flows from the breather pipe 80 through the opening 82 into the air cleaner 2.
Sent to the department.

Next, when the piston 24 descends,
Since the pressure in the crank chamber 16 is positive, the valve plate 72 of the one-way valve 70 forming the second oil supply means is opened by the positive pressure, and the oil mist formed by the crank web 64 is passed through the communication passage 32. It is sent to the valve drive unit 30 and the valve train chamber 34.

When the piston is lowered, excessive supply of oil to the valve drive unit 30 and the valve operating chamber 34 is prevented. That is, the valve plate 72 of the one-way valve 70
Is released, the mist-converted oil in the crank chamber 16 is sent to the communication passage 32, and the communication passage 32 communicates with a small hole 110 formed in the lower surface wall 14 </ b> A of the crankcase 14. Since a part of the oil sent to the communication passage 32 is returned into the oil reservoir 18, the amount of the oil mist sent to the valve drive unit 30 and the valve operating chamber 34 is appropriately adjusted.

Next, when the engine 1 is turned over with the carburetor side facing down, the openings 84D, 8 shown in FIG.
By the inclined position of 4D ', the sphere of the check valve 100 moves toward the side where the return oil passage 84 can be closed by gravity, that is, toward the opening 84D' located below the oil level, Close the located opening 84D '. As a result, the return oil passage 84 located below the oil level is maintained in a state where the communication between the oil sump chamber 18 and the valve operating chamber 34 is shut off. Is reliably prevented from flowing back. Moreover, the opening 84D located above the oil surface is
Since the sphere of the check valve 100 does not block the return oil passage 84, it is possible to release the pressure rise above the oil reservoir 18.

Next, another embodiment according to the embodiment of the present invention will be described. FIG. 4 is a schematic view showing the openings 84D, 84D 'of the return oil passages 84, 84' shown in FIGS. 1 and 2, and this figure also has the same gist as FIG. In FIG. 4, the openings 84D and 84D 'are provided with return oil passages 84 and 8 respectively.
They are parallel to each other as in the extension direction of 4 '. Opening 8
4D and 84D 'are provided with stepped portions 84P and 84 on the inner surface thereof.
P ′ is provided. The steps 84P and 84P 'are formed with reference to the axes P and P' of the return passages 84 and 84 'in FIG.
As shown in FIG. 5B, a space portion having a cross-sectional area expanded toward the oil surface side, and a space portion having a perfect circular cross-sectional shape as shown in FIG. And are continuous,
The boundary between the respective spaces is formed as an inclined surface so that the sphere of the check valve 100 can easily fall toward the space having a circular cross section.

Since the present embodiment has the above configuration,
When the engine 1 is laid down with the carburetor side down, as shown in FIG. 4, of the steps 84P and 84P ',
The return oil passage 84 'is closed at the opening 84D' located below the oil level where the sphere of the check valve 100 moves by gravity due to gravity. As a result, the return oil passage 84 'in which the opening 84D' is located below the oil level is shut off by the check valve 100, and the communication between the oil reservoir 18 and the valve operating chamber 34 is maintained. Become. As a result, the backflow of oil from the oil reservoir 18 to the valve operating chamber 34 is prevented. Also in this embodiment, since the check valve 100 is not blocked by the sphere at the opening 84D located above the oil level, the rising pressure in the oil reservoir 18 can be released.

[0038]

According to the first aspect of the present invention, when the four-stroke engine is in an overturned state around the axis of the crankshaft, the oil reservoir chamber is formed in one of the openings provided in the pair of return oil passages. One is located above the oil level and the other is positioned so as to be located below the oil level and is inclined so as to approach each other toward the oil level. At the opening, the sphere separates from the return oil passage by gravity, and at the other opening below the oil level, the sphere can move to a position that closes the return oil passage by gravity. As a result, a state in which one of the return oil passages is not blocked is maintained, so that the rising pressure in the oil reservoir can be released, and smooth engine lubrication can be achieved.

According to the second aspect of the present invention, when the four-stroke engine is in an overturned state about the axis of the crankshaft, one of the openings parallel to each other is provided above the oil surface of the oil reservoir. And the other is located below the oil level and arranged in parallel with each other, and a step-like step is formed on the inner surface on the oil level side, and a sphere of a check valve is formed on the step at the opening below the oil level. Is positioned with the return oil path closed by gravity,
The state in which the return oil passage is not blocked above the oil level is maintained, so that the rising pressure in the oil reservoir can be released, and smooth engine lubrication can be achieved.

[Brief description of the drawings]

FIG. 1 shows a lubrication device according to an embodiment of the present invention applied 4
FIG. 3 is a schematic diagram showing a state in which a piston is at a top dead center for describing a lubrication path in a cycle engine.

FIG. 2 shows a lubrication apparatus according to an embodiment of the present invention;
FIG. 4 is a schematic diagram showing a state in which a piston is at a bottom dead center for describing a lubrication path in a cycle engine.

FIG. 3 is a schematic diagram for explaining a configuration of an opening of a return oil passage shown in FIG. 1;

FIG. 4 is a schematic diagram for explaining another embodiment relating to the opening of the return oil passage shown in FIG. 1;

5A is a front view of the opening shown in FIG. 4; FIG. 5A is a cross-sectional view taken in the direction indicated by the symbol A in FIG. 4; FIG.
It is an arrow sectional view of the direction shown by the code | symbol B inside.

[Description of Signs] 1 Engine 18 Oil reservoir 34 Valve operating chamber 84, 84 'Return oil path 84D, 84D' opening 84P, 84P 'stepped portion which communicates the valve operating chamber with the oil reservoir.

[Procedure amendment]

[Submission date] March 27, 2001 (2001.3.2)
7)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toyoki Minegishi 35-Ooka, Numazu-shi, Shizuoka Prefecture F-term within Fuji Robin Co., Ltd. 3G013 AB03 BB12 BD47 CA01

Claims (2)

[Claims] An oil reservoir (18) provided near a crank chamber (16) on which a crank shaft (20) is pivotally supported accommodates the crank chamber (16) and intake and exhaust valve mechanisms. Oil is supplied to the valve operating chamber (34) to lubricate each part,
In a lubricating device for a four-cycle engine that circulates oil, one end in the extension direction opens in the valve operating chamber (34), and the other end in the extension direction opens in the oil reservoir (18) and the crankshaft. A pair of return oil passages (84, 84 ') are provided on both sides of the axis of (20), and the return oil passages (8, 84') are provided.
4, 84 '), the openings (84D, 84D') on the oil sump (18) side are located around the axis of the crankshaft (20) when the four-stroke engine is turned sideways. 18) one of which is arranged above the oil level and the other is positioned below the oil level, and is provided so as to be inclined toward the oil level so as to approach each other to close the oil path inside. Check valve (10
0), a lubricating device for a four-stroke engine. 2. The crank chamber (16) and intake / exhaust valve mechanisms are accommodated from an oil reservoir (18) provided near a crank chamber (16) that supports a crank shaft (20). Oil is supplied to the valve operating chamber (34) to lubricate each part,
In a lubricating device for a four-cycle engine that circulates oil, one end in the extension direction opens in the valve operating chamber (34), and the other end in the extension direction opens in the oil reservoir (18) and the crankshaft. A pair of return oil passages (84, 84 ') are provided on both sides of the axis of (20), and the return oil passages (8, 84') are provided.
4, 84 '), the openings (84D, 84D') on the oil sump (18) side are located around the axis of the crankshaft (20) when the four-stroke engine is turned sideways. 18) One is positioned above the oil level and the other is positioned below the oil level and arranged in parallel with each other, and stepped steps (84P, 84P ') are formed on the inner surface on the oil level side. A lubricating device for a four-stroke engine, wherein a check valve (100) having a sphere capable of closing a return oil passage is provided therein.