JPS62129510A - Lubricating oil supplying device for engine - Google Patents

Abstract

PURPOSE:To suppress a pressure fluctuation in a discharge passage communicating a discharge port of an oil pump with a portion of an engine to be supplied with a lubricating oil, and continuously supply the lubricating oil, by providing an air chamber in the discharge passage. CONSTITUTION:An oil pump 10 is fixed at a front lower portion of a cylinder block 1. The oil pump 10 is provided with a housing 13 having a suction port 11 communicated with an oil tank 9 and plural discharge ports 12 corresponding to cylinders and provided with a ring gear 15 meaning with a drive gear 14 of a crank shaft 3. As the opening angle of a throttle valve increases, the operating angle of a lever 32 increases through a lever 35 and a link 33, thereby increasing a discharge quantity of the oil pump 10. Discharge houses 24-26 communicating the discharge ports 12 of the oil pump 10 with intake manifolds 7 are provided at their respective intermediate portions with check valves and air chambers 37. Thus, a pressure fluctuation may be suppressed by the air chambers 37 to thereby render the flow of a lubricating oil continuous.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to lubricating oil supply for an engine in which lubricating oil is supplied to various parts of the engine by an oil pump from a system separate from the fuel.

(Prior art) A conventional lubricating oil supply device includes an oil pump that is driven by the rotation of a crankshaft and discharges oil intermittently, and a discharge passage that communicates the oil pump's discharge port with the lubricated portion of the engine. , an engine in which a pump lever connected to an oil pump discharge amount adjusting section and a throttle lever connected to a throttle valve shaft are linked, and the oil pump discharge amount can be varied according to changes in the opening degree of the throttle valve. There was a lubricating oil supply device (Japanese Patent Laid-Open No. 59-5
Publication No. 12).

(Problems to be Solved by the Invention) In the conventional lubricating oil supply device described above, the discharge amount is varied in accordance with changes in the opening degree of the throttle valve. It will be supplied to the manifold.

However, in the past, the discharge passage that communicated the oil pump's discharge port with the engine's intake manifold had approximately the same cross-sectional area over its entire length. The supply pressure characteristic B of the lubricating oil that is supplied pulsates approximately corresponding to the discharge pressure characteristic A of the lubricating oil that is intermittently discharged from the oil pump.

For this reason, it is not possible to constantly supply lubricating oil to the engine, and for example, during idling operation with the throttle valve opening minimized, there are times when lubricating oil is not supplied into the cylinder, resulting in smooth operation. This had the disadvantage that proper lubrication was not possible. In particular, when a single oil pump is attached to a multi-cylinder engine and branches from this oil pump are used to intermittently supply lubricating oil to each cylinder,
The above drawbacks were noticeable.

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine lubricating oil supply device that can provide smooth lubrication at all times by continuously discharging the W4 oil on the downstream side of the oil pump's discharge path.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a structure in which an air chamber is provided in the middle of a discharge path that communicates the discharge port of the oil pump with the supplied part of the engine. It is something.

(Function) Since the present invention has the above configuration, when lubricating oil is intermittently discharged into the discharge passage by the oil pump and the pressure of the discharge passage fluctuates, the air in the air chamber contracts and expands. .

As a result, pressure fluctuations in the discharge passage located downstream of the air chamber are moderated and averaged, and the lubricating oil flowing out from this part becomes continuous.

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

FIG. 1 is a front view showing a two-stroke, three-cylinder outboard engine to which the present invention is applied, and FIG. 2 is a cross-sectional view of essential parts showing an oil pump used in the engine and its discharge passage.

Three cylinders are formed in the cylinder block 1, upper and lower.
A vertical crankshaft 3 is rotatably supported between the cylinder block 1 and the crankcase 2, and a drive shaft 3a disposed within the propulsion unit of the outboard motor is connected to the lower end of the crankshaft 3. ing.

A piston 4 is housed in each cylinder, and each piston 4 is connected to the crankshaft 3 via a connecting rod 5.

A carburetor 8 is connected to the crank chamber 6 of each cylinder via an intake manifold 7.

In addition, in the figure, 9 is an oil tank that stores lubricating oil.

An oil pump 10 is fixed to the front lower part of the cylinder block 1.

As shown in FIG. 2, the oil pump 10 has a suction port 11 communicating with the oil tank 9 and a discharge port 1 corresponding to each cylinder.
2, a driven gear 15 that meshes with the drive gear 14 fixed to the crankshaft 3, a ring gear 16 that meshes with the driven gear 15, and one suction port 1.
a revolving body 18 that forms a plurality of oil chambers 17 that communicate intermittently with the first and third discharge ports 12, and is integrated with a ring gear 16 and rotatably supported by the housing 13; a plunger 19 that is housed in each oil chamber 17 and reciprocates up and down within the oil chamber 17; a spring 2o that biases the plunger 19 downward; It has a cam 22 that can be pushed upward.

That is, as the crankshaft 3 rotates, the driving gear 14 and the driven gear 15 . When the rotating body 18 rotates within the housing 13 through the meshing of the driven gear 15 and the ring gear 16,
Each plunger 19, which rotates with the rotation of the revolving body 18, performs pumping work by moving up and down in the oil chamber 17 through contact between its pin 21 and cam 22, and
Suction hose 2 connected to suction pipe 11a connected to
The lubricating oil sucked from the oil tank 9 through the pipe 3 is transferred from each discharge pipe 12a connected to each discharge port 12 to each discharge hose 24.
, 25 and 26, it is force-fed to the intake manifold 7 of each cylinder, and can be discharged into the air-fuel mixture.

Furthermore, the oil pump 10 includes an adjustment plate 27 that is inserted into the inner circumference of the ring gear 16 so as to be able to move up and down, and a spring 28 that biases the adjustment plate 27 downward and integrated into the adjustment plate 27. The adjustment cam 30 pushes the tip of the pin 29 upward.

The upper surface of the adjustment plate 27 is brought into contact with the lower surface of the plunger 19 to regulate the lower end position of the plunger 19. Therefore, by regulating the reciprocating stroke of the plunger 19, it is possible to regulate the maximum discharge amount of the oil pump 10. It is said that

Here, a pump lever 32 is fixed to a cam shaft 31 of an adjustment cam 30 protruding from the housing 23, and a throttle lever 35 connected to a throttle valve shaft 34 via a link 33 is coupled to the pump lever 32. has been done.

That is, as the opening degree of the throttle valve increases, the operating angle of the pump lever 32 and the adjusting cam 30, that is, the amount of clockwise rotation in FIG. , the reciprocating stroke of the plunger 19 increases, and the discharge hkQ of the oil pump 10 can be increased as shown in FIG. 3.

, τ, iron, the starting end of the discharge path 38 where each discharge port 12 of the oil pump 10 and each intake manifold 7 communicate, that is, the outlet portion of the discharge port 12, and the middle of the discharge path 38, that is, each hose 24. - A check valve 36 and an air chamber 37 are attached to the intermediate portions of 25 and 26, as shown in FIG.

That is, at the outlet portion of each discharge port 12, the ball 36a is pushed outward (on the discharge side) of the discharge port 12 by the reaction force of the coil spring 3Gb.
A reverse ratio valve 36 is attached to the hoses 24, 25, and 26, and an air chamber 37 made of a hollow body is arranged upside down and connected to the intermediate portion of each of the hoses 24, 25, and 26.

Next, the operation mode of the above embodiment will be explained.

When the throttle lever 35 is rotated with the engine started, the adjustment cam 30 is rotated via the link 33 and the pump lever 32, and the adjustment plate 27 is adjusted in the vertical direction. As a result, the stroke of the re-plunger 19 is regulated, and the discharge amount Q of the oil pump 10 is adjusted according to the discharge characteristics shown in FIG. The air is pressure-fed through the check valve 36 toward the discharge hoses 24 , 25 , and 26 , and is supplied to each intake manifold 7 .

In this case, as shown in FIG. The pressure within the hose is relaxed and averaged, resulting in a substantially continuous supply pressure characteristic C downstream of the discharge hose 24 (25, 26).

Therefore, the lubricating oil flows continuously from the downstream ends of the discharge hoses 24 (25, 26) to the intake manifold 7.

(Effects of the Invention) As is clear from the above description, according to the present invention, since the air chamber is provided in the middle of the discharge path, the lubricating oil discharged discontinuously from the oil pump is removed from the air chamber. Relaxed and always continuous LZ'd+ downstream of the discharge path
ε will be produced.

Therefore, the present invention has the effect of being able to constantly and smoothly supply lubricating oil over the entire range of engine output.

[Brief explanation of drawings]

Fig. 1 is a front view showing a 2-stroke, 3-cylinder outboard engine to which an embodiment of the present invention is applied, and Fig. 2 is a cross-section of essential parts showing an oil pump used in the same engine and its discharge flow path. Figure 3 is a diagram showing the discharge characteristics of the oil pump, Figure 4 is a diagram showing the discharge pressure characteristics of the oil pump, and Figure 5 is a diagram showing the discharge pressure characteristics of the oil pump.
The figure is a diagram showing discharge pressure characteristics of a conventional oil pump. 2: crank case, 3: crankshaft, 6: crank chamber, 7: intake manifold, 8: carburetor, 10 oil pump, 11: suction port, 12: discharge port, 19 nib plunger, 23: suction hose, 24/25/26: Discharge hose,
27: Adjustment plate, 30: Adjustment cam, 32: Pump lever,
33: Link, 34 Nislot valve shaft, 35: Throttle lever, 36: Check valve, 37 Two air chambers, 38
:Discharge path. Application agent Hisashi Matsumoto

Claims (1)

[Claims] 1. An engine lubricating oil supply device that is provided with an oil pump that performs an intermittent discharge operation, a discharge passage that communicates a discharge port of the oil pump with a lubricated portion of the engine, and that makes the discharge amount of the oil pump variable. A lubricating oil supply device for an engine, characterized in that an air chamber is provided in the middle of a discharge path.