JPH0749767B2 - Lubricating oil pump for 2-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine in a two-cycle engine separated oil supply system or an intake pipe connecting the engine and a carburetor, an intake passage of the carburetor, a float chamber of the carburetor, and the like. The present invention relates to a lubricating oil pump for supplying lubricating oil to the consumer part of the vehicle, and is often used in a two-cycle engine mounted on a motorcycle, an outboard motor, or the like.

[Prior Art] Conventionally, for supplying lubricating oil to a generally used two-cycle engine, an oil tank is arranged below the engine, and a lubricating oil pump sucks the oil in the oil tank to consume the oil. The amount of oil sucked into the lubricating oil pump is the same as the amount of oil sucked into the lubricating oil pump. , Matches the amount of oil discharged from the lubricating oil pump.

What happens is that when the engine speed is constant, the stroke of the plunger is the same and the stroke of discharge is the same, so the volume change in the cylinder is the same, so the amount of oil sucked into the lubricating oil pump and the amount of discharge The amount of oil used is the same.

In a low engine speed range such as idling of the engine, the amount of oil supplied to the engine may be a very small amount of, for example, 1 cc per hour. Exhaust gas contains a large amount of white smoke, which causes a white smoke problem.

[Problems to be Solved by the Invention] According to such a conventional lubricating oil pump, the following improvements are desired.

When the engine is started from an empty state where no oil is stored in the lubricating oil pump, the oil flow from the oil tank located below to the engine via the lubricating oil pump is The oil in the oil tank is sucked into the pump chamber of the oil pump, and then the oil in the pump chamber is discharged to the engine.

It should be noted that, for example, when the condition for starting the engine is in the low speed rotation state (low speed rotation is preferable at the time of starting the engine to avoid runaway etc.), the oil from the oil tank to the lubricating oil pump Inhalation of very small doses (eg
1cc / 1 hour) Therefore, when the oil tank and the lubricating oil pump are arranged far from each other, the oil flows 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 the lubricating oil to the engine even though the engine is already operating.
For this reason, in the past, the positions of the lubricating oil pump and the oil tank were brought close to each other, or the passage diameter of the oil inflow passage was set to a minimum to speed up the oil intake, and further, the lubricating oil pump was In order to operate from this state, the engine seizure was prevented by always performing a preliminary operation before starting actual work. However, according to this, the degree of freedom in arranging the oil tank is limited, the degree of freedom in designing the entire engine is low, and the handling is troublesome.

The oil in the oil tank is consumed by the operation of the engine and gradually decreases, and the head difference between the oil surface in the oil tank and the suction passage of the lubricating oil pump gradually increases. According to this, the amount of oil sucked into the pump chamber tends to decrease, and the mixing ratio of the fuel and the oil during the idling operation of the engine, in which it is particularly necessary to supply an accurate amount of oil, changes slightly, which is not preferable.

[Means for Solving the Problems] The lubricating oil pump for a two-cycle engine according to the present invention has been made in view of the above-mentioned problems. To provide the pump that can be supplied, in order to achieve the above purpose,
With respect to the distributor, which rotates in synchronization with the output shaft of the engine and is rotatably arranged in the distributor housing cylinder hole formed in the pump main body, with respect to the longitudinal axis XX of the distributor. (H) is eccentric to the side and is movably arranged in a metering cylinder hole which is opened at the upper end of the distributor along the longitudinal axis XX and is movably arranged. The upper end that protrudes from the upper end is elastically pressed against the cam surface of the cam body to contact it, the oil storage chamber provided in the pump body, and the output shaft of the engine rotate synchronously And a charge suction passage for connecting the charge pump chamber and the oil tank with each other, and a charge pump passage for connecting the charge pump chamber and the oil storage chamber. A rotary pump having a charge discharge passage, an oil leak passage having one end opening to the oil storage chamber and the other end connecting to the oil tank, and a metal ring having one end connecting to the charge discharge passage and the other end opening to the distributor housing cylinder hole. A suction passage and a metering discharge passage whose one end is connected to the consuming portion and the other end is opened to the distributor cylinder hole,
It is bored in the distributor, one end opens to the metering pump chamber formed by the metering cylinder hole and the metering plunger, and the other end is arranged to face the metering suction passage. The first flow path that communicates the metering suction passage with the metering pump chamber only during the suction stroke of the ring pump chamber, and the distributor are provided with one end that opens into the metering pump chamber and the other end discharges the metering ring. A lubricating oil pump is constituted by a second flow path that is arranged so as to face the path and that connects the metering discharge path and the metering pump chamber with each other only during the discharge stroke of the metering pump chamber by the metering plunger. is there.

[Operation] When the engine is operated, the distributor and the rotary pump rotate synchronously. According to this, the oil in the oil tank is immediately sucked into the charge pump chamber through the charge suction passage, and then supplied into the oil storage chamber through the charge discharge passage.

On the other hand, since the metering plunger rotates while contacting the cam surface, suction and discharge actions occur in the metering pump chamber, and the oil flowing in the charge discharge path is metered through the first flow path by this suction stroke. Oil is sucked into the pump chamber and then oil is supplied from the metering discharge passage to the consuming portion through the second passage.

Further, since the amount discharged from the charge pump chamber into the oil storage chamber is larger than the amount of oil supplied from the metering pump chamber to the consuming portion, the residual oil not sucked into the metering pump chamber is It is returned into the oil tank via the oil leak passage.

[Embodiment] An embodiment of a lubricating oil pump for a two-cycle engine according to the present invention will be described below with reference to FIG.

A is an oil tank that stores lubricating oil (hereinafter referred to as oil) inside, and B is a lubricating oil pump that supplies the oil in the oil tank A to a consuming portion C such as a two-cycle engine (hereinafter referred to as engine), Generally, the oil tank A is arranged below the lubricating oil pump B.

The lubricating oil pump B will be described in detail. Reference numeral 1 denotes a pump body in which a distributor housing cylinder hole 2 is formed in the vertical direction. Below the distributor housing cylinder hole 2, a gear housing recess 3 and a cylinder hole 4 are continuously formed to form a distributor. Viewer storage cylinder hole 2
Of the cylinder hole 4 opens upward, while the lower part of the cylinder hole 4 opens downward.

A worm gear 6 that rotates in synchronization with an output shaft (not shown) of the engine is rotatably supported by the pump body 1 and opens in the gear storage recess 3.

Reference numeral 7 denotes a distributor that is liquid-tightly and rotatably inserted in the distributor housing cylinder hole 2, and has an outer shape portion (above the middle portion in the drawing) inserted in the distributor housing cylinder hole 2. Has a cylindrical shape, and the lower end 7A projecting into the gear accommodating recess 3 has a short outer shape.

A metering cylinder hole 8 is formed downward from the upper end 7B of the distributor 7 by eccentricity (h) laterally from the longitudinal axis direction X-X of the center of the distributor 7. A metering plunger 9 is arranged in a liquid-tight manner so as to be movable in the vertical direction, and an upper end 9A of the metering plunger 9 is a cam body that closes the upper opening of the distributor housing cylinder hole 2. The cam surface 11 of 10 is pressed against the cam surface 11. Cam body
The cam surface 11 of 10 is the longitudinal axis direction X of the distributor 7.
It will be formed eccentric by (h) from -X.

A spring 12 is contracted between the collar portion 9B of the metering plunger 9 and the upper end 7B of the distributor 7. Then, the metering plunger 9 disposed in the metering cylinder hole 8 forms the metering pump chamber P ₁ in the metering cylinder hole 8.

Reference numeral 5 denotes a cylindrical pump rotor eccentrically (y) with respect to the center of the cylinder hole 4 and rotatably arranged in the cylinder hole 4, and a pair of grooves 13 formed in the pump rotor 5 , 13 are plate-shaped vanes 14, 14 which rotate while being pressed against the inner circumference of the cylinder hole 4 by the centrifugal force generated by the rotation of the pump rotor 5.

Thus, the charge pump chamber P ₂ which is liquid-tightly divided from each other is formed between the outer periphery of the pump rotor 5, the inner periphery of the cylinder hole 4, and the adjacent vanes 14, 14. the pump rotor 5 by which is disposed eccentrically with respect to the cylinder bore 4, the charge pump chamber P ₂ on the side where the chamber volume of the charge pump chamber P ₂ is increased by the rotation of the pump rotor 5, one end oil tank a The charge pump chamber on the side where the continuous charge suction passage 18 opens and the chamber volume of the charge pump chamber P ₂ due to the rotation of the pump rotor 5 decreases
A charge discharge path 19 that connects to an oil storage chamber described later opens at P ₂ .

Then, as the pump rotor 5 rotates, the oil in the oil tank A is sucked into the charge pump chamber ₂ from the charge suction passage 18, and the pump rotor 5 further rotates, thereby removing the oil in the charge pump chamber P ₂ . The oil is compressed and pushed out through the charge discharge passage 19 into the oil storage chamber described later to be discharged.

Such a rotary pump D is known as a vane pump, and is shown in JIS B 0142, for example.

Further, a rectangular recess 5A is formed downward from the upper surface of the pump rotor 5.

Reference numeral 15 denotes a rotation transmitting body which is arranged in the gear accommodating recess 3 and has a cylindrical outer periphery on which a parallel gear 16 meshing with the worm gear 6 is cut. Rectangular groove 15 that fits into the rectangular protrusion of
A is bored, and a rectangular protrusion 15B that fits into the rectangular recess 5A of the pump rotor 5 is formed on the lower surface.

Then, when the worm gear 6 rotates, the rotation is transmitted to the parallel gear 16 and the rotation transmitting body 15 rotates, whereby this rotation is transmitted from the rectangular groove portion 15A to the lower end portion 7A of the distributor 7 and is distributed. The viewer 7 rotates, and on the other hand, the rotation is transmitted from the rectangular protrusion 15B to the recess 5A of the pump rotor 5, and the pump rotor 5 rotates. Also,
Reference numeral 17 denotes an oil storage chamber provided at an upper opening of the distributor housing cylinder hole 2, and the upper opening of the oil storage chamber 17 is closed by the above-mentioned cam body 10, whereby the oil storage chamber 17 is It is sealed. (In this embodiment, the distributor cylinder hole 2 is opened to the upper end surface 1A of the pump body 1 via the oil storage chamber 17, and the opening is closed by the cam body 10 arranged on the upper end surface 1A. The following passages are bored in the pump body 1. 20
Is a metering suction passage whose one end is open to the charge discharge passage 19 and the other end is opened to the distributor housing cylinder hole 2, and 21 is one end which is the distributor housing cylinder hole 2
A metering discharge passage having the other end connected to the consuming portion C, 22 has one end open to the oil storage chamber 17 and the other end to the oil tank A.
It is an oil leak passage that was contacted by.

Further, the distributor 7 is provided with the following communication. That is, in the left cross section of the distributor 7,
One end opening to the metering pump chamber P _1, a first flow passage 23 for opening and closing the metering suction passage 20 by the rotation of the distributor coater 7, one end opening to the metering pump chamber P _1, the distributor terpolymers 7 times Discharge path 21 by motion
And a second flow path 24 for opening and closing.

More specifically, in the suction process in which the metering plunger 9 moves upward due to the rotation of the distributor 7 to increase the chamber volume of the memory pump chamber P ₁ ,
The first flow path 23 and the metering suction path 20 communicate with each other and the second flow path 24 and the metering discharge path 21 are blocked, while the distributor 7 further rotates and the metering plunger 9 moves downward. Then, in the discharge process of reducing the chamber volume of the metering pump chamber P ₁ , the first flow path 23 and the metering suction path 20 are blocked, and the second flow path 24 and the metering discharge path 21 communicate with each other.

25 is located at the lower end of the pump body 1 and has a cylinder hole 4
Is a lower blocking plate that holds the block.

Next, the operation will be described.

When the engine is operated while the lubricating oil pump B is empty, the worm gear 6 rotates due to the rotation of the output shaft (not shown) of the engine. According to this, the distributor 7 and the pump rotor 5 rotate synchronously when the rotation transmission body 15 rotates via the parallel gear 16.

Here, a more specific description will be given based on FIG. 3 schematically illustrating the actual intake and discharge strokes of the lubricating oil pump B.

This FIG. 3 is from left to right of the drawing.
The four upper strokes in the up, down, and e strokes of a, b, c, and d are the metaling plungers 9.
And the cam surface 11. The second figure shows the operation of the metering discharge passage 21 and the second flow path 24, and the third figure shows the relationship of the metering suction path 20 and the first flow path 23. The action diagram and the fourth (bottom) C diagram show the suction and discharge strokes of the rotary pump D. (Since the diagram is viewed from the lower side, the rotation with the distributor 7 is set in the opposite direction.) First, the state shown in Fig. 8A shows the suction stroke of the pump. First, the metering pump chamber P ₁ will be described. At the start of suction in the suction stroke,
The metering plunger 9 is located at the lowest point a of the cam surface 11 and is moved to the highest point b by the rotation of the distributor 7. According to this, the metering plunger 9 moves upward by the stroke S in the height direction from the point of the cam surface 11a to the point b to increase the volume of the metering pump chamber P ₁ . At this time, as shown in the figure, since the first flow path 23 is in communication with the metering suction passage 20, oil is sucked from the charge discharge passage 19 by the increase in the volume of the metering pump chamber P ₁ .

(However, when the lubricating oil pump is completely empty, oil cannot be sucked in the charge discharge passage 19 for the first rotation, so oil cannot be sucked, but since it flows in the charge discharge passage 19 for the second rotation of the distributor 7. This oil can be sucked in.) At this time, the second flow path 24 is not communicated with the metering discharge path 21 as shown in FIG.

On the other hand, in the rotary pump D, the chamber volume of the m chamber opened to the charge suction passage 18 of the charge pump chamber P ₂ increases, so that the oil in the oil tank A is sucked into the m chamber from the charge suction passage 18.

Next, when the rotation transmitting body 15 further rotates to reach the position shown in the figure B, in the metering pump chamber P ₁ , the metering plunger 9 moves in parallel to the uppermost point B of the cam surface 11,
The vertical movement of the metering plunger 9 has stopped,
Further, as shown in FIGS. 6A and 6B, the second flow path 24 is cut off from the metering discharge path 21 and the first flow path 23 is cut off from the metering suction path 20, so that it does not perform any pumping action.

On the other hand, in the rotary pump D, m of the charge pump chamber P ₂
Since the chamber volume of the chamber is further increased, an amount of oil commensurate with this is further sucked through the charge suction passage 18.

Next, when the rotation transmitting body 15 further rotates and reaches the position shown in C, the metering plunger 9 moves the uppermost point c of the cam surface 11.
(It is the same height as the cam surface b, but is divided for the sake of easy description) to the lowest point d (the same height as the cam surface a).

According to this, the metering plunger 9 moves downward by the stroke S of the cam surface to reduce the chamber volume of the metering pump chamber P ₁ .

At this time, since the second passage 24 and the metering discharge passage 21 are in communication with each other, the oil sucked into the metering pump chamber P ₁ is consumed through the second passage 24 and the memory discharge passage 21. It is supplied to the part C.

The first flow passage 23 is a metering suction passage as shown in FIG.
Cut off 20.

On the other hand, in the charge pump chamber P ₂ , the chamber volume in the m chamber becomes the maximum and the oil in the m chamber is filled with the charge suction passage 18
More inhaled.

Next, when the rotation transmitting body 15 further rotates and becomes as shown in FIG.
The metering plunger 9 moves the lowest point d of the cam surface 11 in parallel. (This point d is the same height as point a) Therefore, the metering plunger 9 does not move at all, the second flow path 24 is blocked from the metering discharge path 21, and the first flow path 23 is metered. Since it is cut off from the suction passage 20, it does not act as a pump.

On the other hand, in this state, in the rotary pump D, the m chamber of the charge pump chamber P ₂ communicates with the charge discharge passage 19,
Moreover, since the volume of the m chamber is reduced by the rotation, the oil sucked into the m chamber is discharged into the charge discharge passage 19. The oil discharged into the charge discharge path 19 is partially sucked into the metering pump chamber P ₁ through the metering suction path 20 and the first flow path 23 by the rotation of the rotation transmission body 15 thereafter. Other oil is supplied into the oil storage chamber 17 to fill the oil storage chamber 17, and the remaining oil is returned to the oil tank A through the oil leak passage 22.

After that, by repeating this process, the metered oil can be supplied from the metering pump chamber P ₁ to the consuming portion C.

Regarding the charge pump chamber P ₂ , the pump chamber m on one side has been described, but the charge pump chamber P ₂ formed by the other vane 14 also operates in the same manner.

Further, although the vane pump has been described as the rotary pump D, the rotary pump such as a gear pump and a trochoid pump can be freely changed. Furthermore, the metering intake passage
Although 20 is opened in the middle of the charge discharge passage 19, it may be opened in the oil storage chamber 17.

[Effects of the Invention] As described above, the lubricating oil pump for a two-cycle engine according to the present invention has the following effects.

The oil that the lubricating oil pump draws from the oil tank is supplied by the rotary pump that constitutes the lubricating oil pump, and the amount of oil is completely independent of the amount of oil that the metering pump chamber measures and supplies to the consuming part. In addition, since it is a large amount of oil, this large amount of oil can be stored in the oil storage chamber in advance by the rotary pump, and this oil can be sucked into the metering pump chamber. In the state where no oil is stored in the pump chamber, for example, in the first operation after leaving the engine for a long period of time, the pump chamber and each passage can be filled with oil very rapidly, so the initial state of engine operation Therefore, the oil can be supplied to the consuming portion without delay, and the operability of the engine can be excellently maintained.

Further, it is not necessary to dispose the oil tank near the lubricating oil pump and the engine, and the degree of freedom in design of the entire engine can be greatly improved.

The rotary pump sucked in a large amount of oil in the oil tank, supplied the desired oil to the metering pump chamber, and returned the remaining oil to the oil tank again, so air bubbles were temporarily generated in the flow passage. However, since the air bubbles could be returned to the oil tank by the flow of a large amount of oil, the air lock that occurred in the flow path could be completely suppressed. Furthermore, since a large amount of oil flows through the pump body. Since the pump main body is cooled and the temperature rise of the pump main body can be suppressed, the generation of bubbles can also be prevented.

For the suction of oil into the metering pump chamber that supplies the measured amount of oil to the consumption part, the oil stored in the oil storage chamber was sucked in advance, so the oil level in the oil tank may drop due to consumption. However, since only the stored oil could be sucked into the metering pump chamber at all times, the suction head could be kept constant, and an accurate discharge amount of oil could be supplied to the engine through the consuming part. It is a thing.

By opening the oil leak passage to the upper part of the oil storage chamber, the air in the oil storage chamber can be effectively returned to the oil tank, so that the air is not sucked into the metering pump chamber and the discharge amount is uniform. It can be controlled to.

When the suction end of the metering suction passage is changed from the charge discharge passage to the oil storage chamber, there is no oil flow rate and the oil separated from the air can be sucked into the metering pump chamber, so the discharge amount of the metering pump is more accurate. You can measure

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a lubricating oil pump for a two-cycle engine according to the present invention, FIG. 2 is a transverse sectional view taken along line II-II in FIG. 1, and FIG. FIG. 7 is a simplified action diagram showing an inhalation and exhalation stroke. 1 …… Pump body 2 …… Distributor housing cylinder hole 3 …… Gear housing recess 5 …… Pump rotor 6 …… Worm gear 7 …… Distributor 8 …… Metaring cylinder hole 9 …… Metaring plunger 11 …… Cam surface 15 ...... Rotational transmission body 17 ...... Oil storage chamber 18 ...... Charge suction passage 19 ...... Charge discharge passage 20 ...... Metalling suction passage 21 ...... Metalling discharge passage 22 ...... Oil leak passage 23 ...... First flow Channel 24 …… Second channel C …… Consumer part A …… Oil tank B …… Lubricating oil pump P ₁ …… Metalling pump chamber P ₂ …… Charge pump chamber D …… Rotary pump

Claims (3)

[Claims] Claims: 1. Distributor 7, which rotates in synchronism with an output shaft of an engine and is rotatably arranged in a distributor housing cylinder hole 2 formed in a pump body 1, and a length of the distributor 7. Direction axis line XX
Is laterally eccentric with respect to h, and is movably arranged in a metering cylinder hole 8 formed by opening at the upper end 7B of the distributor 7 along the longitudinal axis XX. An upper end portion 9A projecting from an upper end 7B of the distributor 7 is elastically pressed against the cam surface 11 of the cam body 10 and is brought into contact with the metering plunger 9, and an oil storage chamber 17 provided in the pump body 1 is provided. , A charge pump chamber P ₂ that rotates in synchronism with the output shaft of the engine to perform suction and discharge operations, and a charge suction passage 18 that connects the charge pump chamber P ₂ to the oil tank A, and a charge pump chamber P 2. a rotary pump D having a charge discharge path 19 for communicating the ₂ and an oil reservoir chamber 17, one end opening into the oil reservoir chamber 17, the other end the oil tank a
To the charge discharge passage 19, and the other end opens to the distributor housing cylinder hole 2, and the metering suction passage 20 opens to the distributor housing cylinder hole 2, and the other end connects to the consuming portion C and the other end connects to the distributor housing cylinder hole 2. A metering discharge passage 21 which is open to the front and a distributor ring 7, one end of which is opened to a metering pump chamber P ₁ formed by a metering cylinder hole 8 and a metering plunger 9, and the other end of which is a metering suction. The metering suction path 20 is arranged so as to face the path 20 and is provided only during the suction stroke of the metering pump chamber P ₁ by the metering plunger 9.
And a metering pump chamber P ₁ and a first flow path 23 that communicates with the distributor 7, one end of which opens to the metering pump chamber P ₁ and the other end of which faces the metering discharge passage 21. The second flow path 24, which is arranged and connects the metering discharge passage 21 and the metering pump chamber P ₁ only during the discharge stroke of the metering pump chamber P ₁ by the metering plunger 9.
A two-cycle engine lubricating oil pump consisting of 2. The amount of oil discharged per unit time from the rotary pump D into the charge discharge passage 19 per unit time discharged from the metering pump chamber P ₁ toward the second flow path 24. A large capacity compared to the discharge amount of oil of
A lubricating oil pump for the two-cycle engine described. 3. The oil leak passage 22 according to claim 1, wherein an opening of the oil leak passage 22 into the oil storage chamber 17 is opened at an upper portion of the oil storage chamber 17.
Lubricating oil pump for cycle engine.