JPH0416604B2 - - Google Patents

Abstract

PURPOSE:To prevent air lock by sucking a large quantity of the oil in an oil tank in the charge suction cycle and supplying the oil into an oil storage cham ber and then supplying the oil into a pump chamber in the metering suction cycle and returning the excessive oil into the oil tank. CONSTITUTION:When a worm gear 4 is revolved through the engine revolution, a cam body 8 revolves, and a plunger body 11 moves vertically in reciprocation, and a large quantity of oil in an oil tank A is sucked into a pump chamber P from a charge suction passage 12, and then discharged and stored into an oil storage chamber 13 through a charge discharge passage 16. Then, the oil in the oil storage chamber 13 is sucked into the pump chamber P through a metering suction passage 17 and supplied into an engine C through a metering discharge passage 14. Since the oil quantity discharged from the pump chamber P into the oil storage chamber 13 is much than the oil quantity sucked into the metering suction passage 17, the excessive oil is returned into the oil tank A through an oil leak passage 15. Thus, even if gas bubbles are generated in the flow passage, the gas bubbles can be returned into the oil tank by the flow of a large quantity of oil, and air lock can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to an engine in a separate oil supply system for a two-stroke engine, an intake pipe connecting the engine and a carburetor, an intake path of a carburetor, a float chamber of a carburetor, This relates to a lubricating oil pump for supplying lubricating oil to consuming parts such as motorbikes, etc., and is often used in two-stroke engines installed in motorcycles, outboard motors, etc.

[Conventional technology]

Conventionally, lubricating oil was supplied to two-cycle engines that were commonly used by placing an oil tank below the engine, and using a lubricating oil pump to suck in the oil in the oil tank and discharge it to the consuming parts. This suction and discharge is performed by changing the volume inside the cylinder, which changes according to the movement of a plunger placed inside the cylinder, and the amount of oil sucked into the lubricating oil pump is equal to Matches the amount of oil.

This is because when the engine speed is constant, the plunger's suction and discharge strokes are
Since they are the same, the volume change inside the cylinder is the same, and therefore the amount of oil sucked into the lubricating oil pump matches the amount of oil discharged.

In a low speed range such as when the engine is idling, the amount of oil supplied to the consumption parts can be as small as, for example, 1 c.c. per hour; if a larger amount than this specified amount is supplied, the engine During combustion, the exhaust gas contains a large amount of white smoke, causing a white smoke problem.

[Problem to be solved by the invention]

According to such a conventional lubricating oil pump, the following improvements are desired.

When the engine starts operating when the lubricating oil pump is empty and no oil is stored in it, the oil flow from the oil tank located below to the consumption part first flows into the pump chamber of the lubricating oil pump. The oil in the oil tank is sucked in, and then the oil in the pump chamber is discharged to the engine via the consumption part.

What should be noted here is that, for example, if the condition when starting the engine is low speed rotation, (low speed rotation is preferable to avoid runaway etc. when starting the engine) oil is transferred from the oil tank to the lubricating oil pump. The inhalation is done in very small doses (for example, 1 c.c. 1 hour). Therefore, if the oil tank and the lubricating oil pump are located apart from each other, oil will flow into the lubricating oil pump only after the oil inflow path connecting the oil tank and the lubricating oil pump is filled.

Therefore, during this period, it may not be possible to supply lubricating oil to the engine via the consumption section even though the engine is already in operation. For this reason, in the past, the lubricating oil pump and oil tank were placed close to each other, or the diameter of the oil inflow path was set to the minimum to speed up oil suction.
Furthermore, in order to operate the lubricating oil pump from an empty state, it is necessary to perform a preliminary operation before starting actual work, thereby preventing the engine from seizing up. However, according to this, the degree of freedom in arranging the oil tank was restricted, the degree of freedom in designing the entire engine was reduced, and furthermore, handling was troublesome.

The oil in the oil tank is consumed by engine operation and gradually decreases, and the head difference between the oil level in the oil tank and the suction passage of the lubricating oil pump gradually increases. According to this, the suction of oil into the pump chamber tends to decrease, and the mixture ratio of fuel and oil changes, however slightly, especially during idling operation of the engine, which requires supply of an accurate amount of oil, which is undesirable.

[Means for Solving the Problems] The lubricating oil pump for a two-stroke engine according to the present invention has been developed in view of the above-mentioned problems, and has a high degree of freedom in arranging the lubricating oil pump and oil tank, and also allows for accurate lubricating oil. In order to achieve the above-mentioned purpose, the pump body 1 is provided with a distributor housing cylinder hole 2 and a cam body housing recess 3; A distributor 5 is housed in a freely movable manner; a distributor 5 is provided with a rotational force by a worm gear 4 that rotates in synchronization with the output shaft of the engine, and has a cam surface 10 that abuts the control rod 19A; a cam body 8 that applies rotational force to the viewer 5; a cylinder hole 6 bored approximately on the center XX in the longitudinal axis direction of the distributor 5; provided integrally with the cam body 8; Cylinder hole 6
Plunger body 11 slidably disposed inside
A spring 20 that presses the cam surface 10 of the cam body 8 against the control rod 19A, and an oil reservoir 13 formed by the upper part of the distributor storage cylinder hole 2 and the closing plate 40; Pump chamber P with plunger body 11 arranged in 6
On the other hand, in the distributor 5, the pump chamber P and the metering discharge passage 14 are formed during the metering discharge stroke of the pump chamber P by the plunger body 11.
During the charge suction stroke of the pump chamber P by the plunger body 11, the pump chamber P and the charge suction passage 12 are communicated, and during the charge discharge stroke of the pump chamber P by the plunger body 11, the pump chamber P and the oil storage chamber 13 are communicated. Charge discharge path 1 connected to
A switching passage 18 is provided to communicate with the metering suction passage 17 that connects the pump chamber P and the oil reservoir chamber 13 during the metering suction stroke of the pump chamber P by the plunger body 11, and further communicates the metering suction passage 17 with the oil reservoir chamber 13. Reference numeral 13 denotes a lubricating oil pump for a two-cycle engine, which has an oil leak passage 15 communicating with the oil tank A.

[Effect]

When the worm gear rotates as the engine operates, the cam body rotates, and as the cam body rotates, the plunger body reciprocates in the cylinder hole in the vertical direction by the cam surface of the cam body. . According to this, oil in the oil tank is sucked into the pump chamber through the charge suction path, and then discharged into the oil storage chamber through the charge discharge path, so that the oil is stored in the oil storage chamber.

Next, the oil in the oil storage chamber is sucked into the pump chamber through the metering suction path, and then supplied from the pump chamber to the consumption section via the metering discharge path.

Note that the amount of oil discharged from the pump chamber into the oil storage chamber via the charge discharge path is larger than the amount of oil sucked into the pump chamber from the metering suction path, so the remaining oil that is not sucked into the pump chamber is an oil leak. It is returned to the oil tank via the passage.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lubricating oil pump for a two-stroke engine according to the present invention will be described below with reference to FIGS. 1 and 2.

A is an oil tank that can store lubricating oil (hereinafter referred to as oil) inside, and B is an oil tank that stores lubricating oil (hereinafter referred to as oil) inside the oil tank. It is a lubricating oil pump that measures and supplies oil to consumption parts C such as the intake passage and the float chamber of the carburetor (both not shown), and is generally used in oil tank A.
is located below the lubricating oil pump B.

Lubricating oil pump B will be explained.

Reference numeral 1 denotes a pump body in which a distributor housing cylinder hole 2 is vertically bored, and a cam body housing recess 3 is provided below the distributor housing cylinder hole 2. Further, a worm gear 4 that rotates in synchronization with engine output (not shown) is rotatably supported in the cam body storage recess 3.

5 is the distributor storage cylinder hole 2
A destroyer is rotatably fitted into the destroyer storage cylinder hole 2.
The outer portion (above the middle portion in the figure) that is fitted into the cam body has a cylindrical shape, and the lower end portion that projects into the cam body storage recess 3 has a rectangular outer shape. A cylinder hole 6 is bored on X-X, approximately at the center of the distributor 5 in the longitudinal axis direction, from the bottom to the top.

Reference numeral 8 denotes a cam body which is disposed in the cam body storage recess 3 and has a cylindrical outer circumference notched with a parallel gear 9 that meshes with the worm gear 4. A cam surface 10 is formed on the lower surface of the cam body 8. Ru. (The specific profile of the cam surface 10 will be described in the section explaining the function.) The recess 8A of the cam body 8 is formed in a rectangular groove shape so that the rotation of the cam body 8 by the worm gear 4 is transmitted to the distributor 5. and is engaged with the rectangle at the lower end of the distributor 5. Furthermore, a plunger body 11 is installed in the center of the cam body 8 in the direction of the distributor 5 (upward in the figure), and this plunger body 11 is airtightly and freely movable within the cylinder hole 6. Placed. A pump chamber P is formed by the cylinder hole 6 and the plunger body 11.

In addition, 12 is a charge suction passage whose one end opens to the distributor housing cylinder hole 2 and the other end communicates with the oil tank A, and 13 denotes an oil storage chamber formed in the upper part of the distributor housing cylinder hole 2. More specifically, it is formed by the upper surface 5A of the distributor 5 and a closing plate 40 that closes the opening.

Note that the protrusion 5B from the upper surface 5A of the distributor 5 is made to protrude to form the oil storage chamber 13, but it may be made to protrude from the closing plate 40, or a stepped part may be formed in the distributor storage cylinder hole 2. It may also be provided to restrict the upward movement of the distributor 5.

14 is a metering discharge passage whose one end opens to the distributor storage cylinder hole 2 and the other end communicates with the consumption part C; 15 indicates an oil leak passage which communicates the oil storage chamber 13 and the oil tank A; and 16 indicates one end. a charge discharge passage 1 which opens into the oil storage chamber 13 and whose other end opens into the distributor storage cylinder hole 2;
7 is a metering suction passage whose one end opens to the oil storage chamber 13 and the other end opens to the distributor storage cylinder hole 2; , the charge discharge passage 16, the charge suction passage 12, and the metering suction passage 17, a switching passage 18 is provided which opens only one passage and keeps the other three passages closed.

Reference numeral 19 designates a control rod 19A (specifically, a protrusion formed by press punching) that is disposed at the lower end of the pump body 1 and closes the lower opening of the cam body storage recess 3, and also contacts the cam surface 10 of the cam body 8. This is the lower obstructing plate provided. 20 has a distributor 5 on one end
The other end of the spring is engaged with the cam body 8 and presses the cam surface 10 of the cam body 8 against the control rod 19A.

Next, its operation will be explained with reference to FIG.

When the engine is operated with the lubricating oil pump B in an empty state, the worm gear 4 rotates in response to the rotation of the output shaft (not shown) of the engine. Worm gear 4
The rotation of is transmitted to the parallel gear 9 that meshes with this,
The cam body 8 rotates. When the cam body 8 rotates, the cam surface 10 of the cam body 8 rotates and moves on the control rod 19A, and according to this, the cam body 8 moves in the vertical direction by the vertical displacement of the cam surface 10. Rotate while moving.

Therefore, the plunger 11 is installed upright from the cam body 8.
It also rotates synchronously with the cam body 8 and reciprocates in the vertical direction. Here, the actual suction and discharge processes in the lubricating oil pump B will be explained in more detail based on FIG. 3, which schematically depicts them.

This figure 3 shows A, B, C, from the left side of the drawing.
Figure A shows the charge suction stroke, Figure B shows the charge discharge stroke, Figure C shows the metering suction stroke, and Figure D shows the metering discharge stroke.

First, the state shown in Figure A shows the charge suction stroke of the pump. At the start of suction in this charge suction stroke, the control rod 19A
0, and thereby the cam body 8 and the plunger body 11 are in the position in which they are originally moved upward in FIG.

During the process in which the distributor 5 rotates counterclockwise from the state at point c and reaches point d, the switching passage 18 is connected to the pump chamber P and the charge suction passage 12.
is in communication state. On the other hand, the control rod 19
Move from point c to point d at 0 and make a charge stroke
A downward displacement of _S1 is applied to the plunger body 11. According to this, a large amount of oil corresponding to the charge stroke _S1 is sucked into the pump chamber P from the oil tank A.

Next, the charge and discharge process will be explained with reference to FIG. At this time, the distributor 5 rotates counterclockwise from point e to point f, and during this time, the switching passage 18 keeps the charge discharge passage 16 open; According to the movement from point to point f, the control rod 19A moves from point e to point f on the cam surface 10, and according to this, the plunger body 11 is moved upward by a charge stroke S of ₁ minute. Therefore, the large amount of oil sucked into the pump chamber P is transferred to the switching passage 1.
8 to the oil storage chamber 13 via the charge discharge passage 16.
Supply oil inside.

Next, the metering suction stroke will be explained with reference to FIG. At this time, the distributor 5 rotates counterclockwise from point g to point f, and during this period, the switching passage 18 keeps the metering suction passage 17 open, and on the other hand, it rotates from point g to point f. According to the movement to point h, the control rod 19A moves downward by a metering stroke _S2 , which is _a stroke smaller than the charge stroke S1.

As a result, the volume of the pump chamber P increases, and the oil in the oil storage chamber 13 is sucked into the pump chamber P via the metering suction passage 17. At this time, since a large amount of oil has already been supplied into the oil storage chamber 13 during the charge discharge stroke, sufficient oil can be supplied during such metering suction.

Next, the metering discharge process will be explained with reference to FIG. At this time, the distributor 5 rotates counterclockwise from point a to point b, and during this period, the switching passage 18 keeps the metering discharge passage 14 open; According to the movement to point b, the control rod 19A is
Charge stroke S: Metering stroke S consisting of a stroke smaller than ₁ , moving upwards by ₂ minutes.

As a result, the volume of the pump chamber P decreases, so that oil is stored in the pump chamber P and is supplied to the consumption part C from the metering discharge path 14.

Note that the amount of oil supplied into the oil storage chamber 13 during the charge discharge stroke is larger than the amount of oil sucked into the pump chamber P from the oil storage chamber 13 during the metering suction stroke, but the remaining amount The oil is returned to the oil tank A through the oil leak passage 15 and does not pose any problem.

〔Effect of the invention〕

As described above, the lubricating oil pump for a two-stroke engine according to the present invention provides the following effects.

The amount of oil sucked into the pump chamber during the charge suction stroke of the lubricating oil pump is completely unrelated to the amount of oil sucked into the pump chamber during the metering suction stroke of the pump, and a large amount of oil is sucked into the pump chamber during the charge discharge stroke. A larger volume of oil is discharged into the oil storage chamber, and this oil is sucked into the pump chamber during the metering suction stroke. This allows the engine to be operated for a long period without oil being stored in each passage, especially when starting the engine. During the first operation after being left in the pump, the pump chamber and each passage can be filled with oil extremely quickly.
Oil can be supplied to the engine via the consumption part without delay from the initial state of engine operation, and the operability of the engine can be maintained in good condition.

Additionally, it is no longer necessary to place the oil tank near the lubricating oil pump and the engine, which greatly improves the degree of freedom in designing the entire engine.

During the charge suction stroke, a large amount of oil in the oil tank is sucked and supplied to the oil storage chamber, and during the metering suction stroke, the desired oil is supplied to the pump chamber, and the remaining oil is pumped back into the oil tank. Even if air bubbles were to occur in the flow path, the air bubbles could be returned to the oil tank by the large flow of oil, completely preventing air locks from occurring in the flow path. Moreover, since a large amount of oil flows through the pump body, the pump body is cooled and the temperature rise in the pump body can be suppressed, and the generation of air bubbles can also be prevented.

In order to supply metered oil to the engine via the consumption part, the oil is drawn into the pump chamber by drawing in the oil that has been warmly stored in the oil storage chamber. Even if the surface drops due to consumption, only the oil stored in the oil storage chamber can be sucked into the pump chamber, so the suction head can always be kept constant, and the exact amount of oil discharged can be maintained. was able to supply this to the organization.

By opening the oil leak passage at the top of the oil storage chamber, the air in the oil storage chamber can be effectively returned to the oil tank, preventing air from being sucked into the pump chamber and controlling the discharge amount uniformly. It is possible.

The opening position of the metering suction passage to the distributor storage cylinder hole is located below the opening position of the metering suction passage to the oil storage chamber, so air mixed in the metering suction passage will naturally escape into the oil storage chamber. This prevents air from entering the pump chamber, eliminates factors that cause errors in oil measurement due to air locks, air compression, etc., and enables accurate metering oil to be supplied to the engine via the consumption section.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a lubricating oil pump for a two-stroke engine according to the present invention, and FIG.
FIG. 3 is a longitudinal sectional view taken along the - line in the figure, and is a simplified operational diagram showing the suction and discharge strokes of the pump. 1... Pump body, 2... Distributor storage cylinder hole, 3... Cam body storage recess, 4...
... Worm gear, 5 ... Distributor, 6
... Cylinder hole, 8 ... Cam body, 10 ... Cam surface, 11 ... Plunger body, 12 ... Charge suction path, 13 ... Oil storage chamber, 14 ... Metering discharge path, 16 ... Charge discharge path , 17... Metering suction passage, 18... Switching passage, C... Consumption part, A... Oil tank, B... Lubricating oil pump, P...
…pump room.

Claims (1)

[Scope of Claims] 1. A pump body 1 provided with a destroyer housing cylinder hole 2 and a cam body housing recess 3; A destroyer 5 rotatably housed in the destroyer housing cylinder hole 2; ; A cam body that is provided with a rotational force by the worm gear 4 that rotates in synchronization with the output shaft of the engine, has a cam surface 10 that contacts the control rod 19A, and that applies rotational force to the distributor 5. 8; A cylinder hole 6 bored approximately on the center X-X in the longitudinal axis direction of the distributor 5; A cylinder hole 6 formed integrally with the cam body 8;
Plunger body 11 slidably disposed inside
and a spring 20 that presses and biases the control rod 19A against the cam surface 10 of the cam body 8, and an oil reservoir 13 formed by the upper part of the distributor housing cylinder hole 2 and the closing plate 40; Pump chamber P with plunger body 11 arranged in 6
On the other hand, in the distributor 5, the pump chamber P and the metering discharge passage 14 are formed during the metering discharge stroke of the pump chamber P by the plunger body 11.
During the charge suction stroke of the pump chamber P by the plunger body 11, the pump chamber P and the charge suction passage 12 are communicated, and during the charge discharge stroke of the pump chamber P by the plunger body 11, the pump chamber P and the oil storage chamber 13 are communicated. Charge discharge path 1 connected to
A switching passage 18 is provided to communicate with the metering suction passage 17 that connects the pump chamber P and the oil reservoir chamber 13 during the metering suction stroke of the pump chamber P by the plunger body 11, and further communicates the metering suction passage 17 with the oil reservoir chamber 13. Reference numeral 13 denotes a lubricating oil pump for a two-stroke engine, which has an oil leak passage 15 communicating with the oil tank A. 2. The amount of oil discharged from the pump chamber P through the charge discharge passage 16 into the oil storage chamber 13 during the charge discharge stroke is the amount of oil discharged from the pump chamber P into the metering discharge passage 14 during the metering discharge stroke. The lubricating oil pump for a two-stroke engine according to claim 1, wherein the pump has a larger capacity. 3 The amount of oil sucked into the pump chamber P from the charge suction passage 12 during the charge suction stroke is determined by the amount of oil sucked into the pump chamber P from the charge suction passage 17 during the metering suction stroke.
The lubricating oil pump for a two-cycle engine according to claim 1, wherein the lubricating oil pump for a two-cycle engine has a large capacity compared to the amount of oil sucked into the pump chamber P. 4. The movement stroke S ₂ of the plunger body 11 during the charge discharge stroke and the charge suction stroke is the same, and the movement stroke S ₂ of the plunger body 11 during the metering discharge stroke and the metering suction stroke is the same, and the charge discharge stroke Movement stroke of plunger body 11 at time
Plunger body 11 during the metering discharge stroke of S ₂
2. The lubricating oil pump for a two-stroke engine according to claim 1, wherein the moving stroke _S2 is larger than the moving stroke S2. 5. The lubricating oil pump for a two-cycle engine according to claim 1, wherein the oil storage chamber 13 is provided in the distributor storage cylinder hole 2 in the upper part of the distributor 5. 6. The lubricating oil pump for a two-cycle engine according to claim 1, wherein the oil leak passage 15 is opened at the upper part of the oil storage chamber 13. 7. Lubricating a two-stroke engine according to claim 1, wherein the opening position of the metering suction passage 17 to the distributor housing cylinder hole 2 is located below the opening position of the metering suction passage 17 to the oil storage chamber 13. oil pump.