JPH0680288B2 - Lubricating oil pump for 2-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an intake pipe of an engine in a separate refueling system of a two-cycle engine or for 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 speed region such as idling of the engine, the amount of oil supplied to the consuming portion may be a very small amount, for example, about 1 cc per hour, and if a larger amount of oil is supplied than this regulation amount, combustion of the engine will occur. Occasionally, a large amount of white smoke is contained in the exhaust gas, 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 consuming section is as follows: The oil in the oil tank is sucked into the pump, and then the oil in the pump chamber is discharged to the consumer.

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, there are cases where the lubricating oil cannot be supplied to the engine as the consuming portion 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 further, 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. (Y) is eccentric to the side, and is movably arranged in a cylinder hole that is opened in the upper portion of the distributor along the longitudinal axis XX and extends from the upper portion of the distributor. A plunger body whose upper end to project is elastically pressed against the cam surface of the cam body and is in contact with the oil body, an oil storage chamber provided in the pump body, and one end of which opens into a cylinder hole,
A metering discharge passage with the other end connected to the consuming part, a charge suction passage with one end opened to the cylinder hole and the other end connected to the oil tank, and a charge discharge with one end opened to the cylinder hole and the other end connected to the oil reservoir. The passage and one end open to the cylinder hole, the other end connects to the oil storage chamber, the metering suction passage, the one end opens to the oil storage chamber, the other end opens to the oil tank, and the oil leak passage connects to the oil tank. , One end opens to the pump chamber formed by the cylinder hole and the plunger body, and the other end opens to the cylinder hole corresponding to the charge suction passage, the charge discharge passage, the metering suction passage, and the metering discharge passage. During the metering discharge process of the pump chamber by the plunger body, only the pump chamber and the metering discharge passage are communicated with each other, and the plunger body performs charge suction operation of the pump chamber. Sometimes the pump chamber communicates only with the charge suction passage, only the pump chamber communicates with the charge discharge passage of the pump chamber by the plunger body, and the pump chamber communicates with the plunger body during the metering suction stroke of the pump chamber. A switching passage is provided to connect only the metering suction passage.

[Operation] When the worm gear is rotated by the operation of the engine, the distributor is rotated, and this rotation causes the plunger body to reciprocate vertically in the cylinder hole by the cam surface of the cam body.

According to this, the oil in the oil tank is sucked into the pump chamber through the charge suction passage and then discharged into the oil storage chamber through the charge discharge passage to store the oil in the oil storage chamber.

Next, the oil in the oil storage chamber is sucked into the pump chamber through the metering suction passage and then supplied from the pump chamber to the consuming portion through the metering discharge passage.

Of the oil discharged from the pump chamber into the oil storage chamber via the charge discharge passage, the oil remaining in the oil storage chamber without being sucked into the pump chamber from the metering suction passage is again returned to the oil tank via the oil leak passage. Returned inside.

〔Example〕

Hereinafter, the lubricating oil pump of the two-cycle engine according to the present invention will be described.
An embodiment will be described with reference to FIGS.

A is an oil tank for storing lubricating oil (hereinafter referred to as oil) inside, and B is lubricating oil for measuring and supplying the oil in the oil tank A to a consuming portion C such as a two-cycle engine (hereinafter referred to as engine). It is a pump, and the oil tank A is generally arranged below the lubricating oil pump B.

The lubricating oil pump B will be described.

1 is the cylinder hole for the distributor in the vertical direction 2
Is a pump body in which a gear accommodating recess 3 is provided below the distributor accommodating cylinder hole 2. The gear storage recess 3 has an engine output shaft (not shown).
A worm gear 4 that rotates in synchronism with is rotatably supported.

Reference numeral 5 is a distributor that is rotatably and liquid-tightly inserted into the distributor housing cylinder hole 2. The worm gear 4 is provided on the cylindrical outer periphery of the distributor 5 that opens in the gear housing recess 3. The meshing parallel gear 6 is cut.

A cylinder hole 7 is formed downward from an upper portion 5A of the distributor 5 which is eccentric to the lateral side from the center XX in the longitudinal axis direction of the distributor 5.

Reference numeral 8 denotes a plunger body which is arranged in the cylinder hole 7 so as to be liquid-tight and slidable, and an upper end portion 8A of the plunger body 8 projects from an upper portion 5A of the distributor 5.
A pump chamber P is formed in the distributor 5 by the cylinder hole 7 and the plunger body 8.

Reference numeral 9 closes the upper opening 2A of the distributor cylinder hole 2 and the upper end of the plunger body 8.
8A is a cam body having a cam surface 10 that is in contact with 8A, and the upper end 8A of the plunger body 8 is always cam surface by the spring 11.
It is pressed and urged to 10. (The specific profile of the cam surface 10 will be described in the section for explaining the operation.) Also, the upper part 5A of the distributor 5 and the distributor housing cylinder hole 2,
Distributor 5 formed by cam body 9
An oil storage chamber 13 is formed in the space located above the.

In addition, 12 has a distributor housing cylinder hole 2 at one end
The charge suction passage (shown in FIG. 2) having the other end connected to the oil tank A, 14 has one end opened to the distributor housing cylinder hole 2, and the other end connected to the consumption part C. A metering discharge passage (shown in FIG. 1), 15 is an oil leak passage (first connection between the oil storage chamber 13 and the oil tank A).
(Shown in the drawing), 16 is a charge discharge path (shown in FIG. 1) whose one end opens into the oil storage chamber 13 and the other end opens into the distributor housing cylinder hole 2, and 17 shows one end of the oil storage chamber 13 The metering intake passage (shown in FIG. 2) with the other end open to the distributor hole cylinder hole 2 (also shown in FIG. 2). A switching passage 18 is provided to connect only one passage of the passage 16, the charge suction passage 12, and the metering suction passage 17 to the pump chamber P and to keep the other three passages from the pump chamber P.

Next, the operation will be described.

When the engine is operated, the worm gear 4 rotates due to the rotation of the output shaft (not shown) of the engine, and the parallel gear 6 receives this rotational force and the distributor 5 rotates. According to this, the upper end portion 8A of the plunger body 8 has the cam surface 10 of the cam body 9.
Since the cam surface 10 is moved upward, the cam surface 10 is rotated while being moved in the vertical direction by the displacement in the vertical direction.

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.
B shows the charge intake stroke, B shows the charge discharge stroke, C shows the metering suction stroke, and D shows the metering discharge stroke.

First, the state shown in (a) shows the charge suction stroke of the pump. At the start of suction in such a charge suction stroke, the upper end portion 8A of the plunger body 8 is located on the lowest point c of the cam surface 10, whereby the plunger body 8 is at the most downwardly moved position in FIG. .

When the distributor 5 rotates counterclockwise in FIG. 3 from the state of point c to reach point d, the switching passage 18 holds only the pump chamber P and the charge suction passage 12 in a communicating state.

On the other hand, when the distributor 5 moves from the point c to the point d, the plunger body 8 moves along the cam surface 10a. According to this, the plunger body 8 moves upward by S _1. To do.

Thus, the volume of the pump chamber P increases correspondingly to the stroke S ₁ , and a large amount of oil corresponding to this increases from the oil tank A into the pump chamber P via the charge suction passage 12 and the switching passage 18. Inhale to. In the charge suction stroke, the metering discharge passage 14, the metering suction passage 17, and the charge discharge passage 16 are shut off from the pump chamber P.

Next, the charge discharge process will be described with reference to FIG. At this time, the distributor 5 further rotates counterclockwise from the above state a to rotate from the point e to the point f. During this rotation, the switching passage 18 includes only the charge discharge passage 16. It is held open. On the other hand, when the distributor 5 moves from the point e to the point f, the plunger body 8 moves from the point e on the cam surface 10b to the point f,
According to this, the plunger body 8 is moved downward by the charge stroke S ₁ to reduce the chamber volume of the pump chamber P, whereby a large amount is sucked into the pump chamber P during the charge suction stroke. A large amount of oil is supplied from the switching passage 18 into the oil storage chamber 13 via the charge discharge passage 16. The charge suction passage 12, the metering discharge passage 14, and the metering suction passage 17 are disconnected from the pump chamber P during the charge discharge process.

Next, the metering suction stroke will be described with reference to FIG. At this time, the distributor 5 further rotates counterclockwise from the state of B to rotate from the point g to the point h, and during this period, the switching passage 18 has only the metering suction passage 17 and the pump chamber P. It is held open. On the other hand, when the plunger body 8 due to the movement up to point h from point g of the cam surfaces 10c, (the low height of the cam) the plunger body 8 the charge stroke S ₁ with a smaller stroke metering stroke S ₂ Move up by a minute.

According to this, since the chamber volume in the pump chamber P slightly increases corresponding to the metering stroke S ₂ , the pump chamber P
The oil in the oil storage chamber 13 is filled with the metering suction passage 17 and the switching passage.
Inhale through 18. At this time, since a large amount of oil has already been supplied to the oil storage chamber 13 during the charge discharge process, there will be no shortage during such metering suction.
During the metering suction stroke, the metering discharge passage 14, the charge suction passage 12, and the charge discharge passage 16 are disconnected from the pump chamber P.

Next, the metering discharge process will be described with reference to FIG.

At this time, the distributor 5 further rotates in the counterclockwise direction from the state of C and rotates from the point a to the point b. During this, the switching passage 18 has the metering discharge passage 14
And only the pump chamber P is held open. On the other hand, when the plunger body 8 moves from the point a on the cam surface 10d to the point b, the plunger body 8 moves to the charge stroke S ₁
Metalling stroke S ₂ consisting of smaller strokes
Move down by a minute.

As a result, the volume of the chamber in the pump chamber P is reduced corresponding to the metering stroke S ₂ , so that the oil stored in the pump chamber P in the metering suction stroke is discharged from the switching passage 18 and the metering discharge passage 14 to the consuming portion C. Is supplied to.

Further, during such a metering discharge process, the charge suction passage 12, the charge discharge passage 16, and the metalling suction passage 17 are shut off from the pump chamber P.

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

Further, the cam surface 10 is specifically formed with four ridges, of which the cam surface 10A for controlling the charge intake stroke and the cam surface 10b for controlling the charge discharge stroke have a cam height so as to form the charge stroke S _1. The cam surface 10C that controls the remaining metering intake stroke and the cam surface 10d that controls the metering discharge stroke have a cam height that is smaller than the cam height of the charge stroke S ₁ so that the metering stroke S ₂ can be formed. To do.

〔The invention's effect〕

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

The amount of oil sucked into the pump chamber during the charge suction stroke of the lubricating oil pump is completely independent of the amount of oil sucked into the pump chamber during the pump's metering suction stroke, and a large amount of oil is sucked into the pump chamber during the charge discharge stroke. A larger amount of oil was discharged into the oil storage chamber, and this oil stored in the oil storage chamber was sucked into the pump chamber during the metering suction stroke.Therefore, the oil was stored in each passage especially when the engine was started. When there is no engine, for example, during 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 that there is no delay from the initial state of engine operation to the consumption section. Oil can be supplied 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.

By 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 returned to the oil tank. Since it was returned, even if bubbles were generated in the flow passage, it was possible to return these bubbles to the oil tank by the flow of a large amount of oil, so it was possible to completely suppress the air lock generated in the flow passage. Furthermore, since a large amount of oil flows through the pump main body, the pump main body is cooled and the temperature rise of the pump main body can be suppressed, so that the generation of bubbles can be prevented at the same time.

In order to supply the measured amount of oil to the consuming part, the oil that had been stored in the oil storage chamber was sucked into the pump chamber in advance, so the oil level in the oil tank would drop due to consumption. However, since only the oil stored in the oil storage chamber was able to be sucked into the pump chamber at all times, the suction head could always be kept constant and an accurate discharge amount of oil could be supplied to the consuming unit. Is.

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 and the air is not sucked into the pump chamber, and the discharge amount is controlled uniformly. It is possible.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a lubricating oil pump for a two-cycle engine according to the present invention, FIG. 2 is a longitudinal sectional view taken along line II-II of FIG. 1, and FIG. FIG. 6 is a simplified action diagram showing a discharge stroke. 1 …… Pump body 2 …… Distributor housing cylinder hole 3 …… Gear housing recess 4 …… Worm gear 5 …… Distributor 7 …… Cylinder hole, 8 …… Plunger body 9 …… Cam body, 10 …… Cam surface 12 …… Charge suction passage, 13 …… Oil storage chamber 14 …… Metalling discharge passage 16 …… Charge discharge passage 17 …… Metalling suction passage 18 …… Switching passage C …… Consumer, A …… Oil tank B …… Lubricating oil pump, P …… Pump chamber

Claims (3)

[Claims] 1. Distributor 5, which rotates in synchronization with an output shaft of an engine and is rotatably disposed in a distributor housing cylinder hole 2 formed in pump body 1, and a longitudinal direction of distributor 5. Direction axis line XX
Is laterally eccentric with respect to y and is movably arranged in a cylinder hole 7 which is bored in the upper portion 5A of the distributor 5 along the longitudinal axis XX and is movably arranged. The upper end that can protrude from the upper part 5A of 5
8A is elastically pressed against the cam surface 10 of the cam body 9 to contact the plunger body 8, an oil storage chamber 13 provided in the pump body 1, one end opens into the cylinder hole 7, and the other end Is a metering discharge passage 14 connected to the consuming portion C, one end is opened to the cylinder hole 7, the other end is connected to the oil tank A, and a charge suction passage 12 is connected to the cylinder hole 7, and the other end is opened to the oil storage chamber. A charge discharge passage 16 connected to 13 and a metering suction passage 17 having one end opened to the cylinder hole 7 and the other end connected to the oil storage chamber 13, and one end opened to the oil storage chamber 13 and the other end being connected to the oil tank A.
Of the oil leak passage 15 and the distributor 5, the charge suction passage having one end opened to the pump chamber P formed by the cylinder hole 7 and the plunger body 8 and the other end opened to the cylinder hole 7. 12, charge discharge path 1
6, the pumping chamber P formed by the plunger body 8 and opening corresponding to the metering suction passage 17 and the metering discharge passage 14
Of the pumping chamber P and the metering discharge passage 14 are communicated with each other during the metering discharge stroke, and only the pump chamber P and the charge suction passage 12 are communicated with each other during the charge suction stroke of the pump chamber P by the plunger body 8. A switching passage 18 that connects only the pump chamber P and the charge discharge passage 16 during the charge discharge stroke of the pump chamber P, and connects only the pump chamber P and the metal ring suction passage 17 during the metalling suction stroke of the pump chamber P by the plunger body 8. A lubricating oil pump for a two-cycle engine, characterized in that 2. The moving stroke S ₁ of the plunger body 8 during the charge suction stroke and the charge discharge stroke is set larger than the moving stroke S ₂ of the plunger body 8 during the metering suction stroke and the metering discharge stroke. The lubricating oil pump for a two-cycle engine according to claim 1. 3. The oil storage chamber 13 is located above the distributor 5.
The lubricating oil pump for a two-cycle engine according to claim 1, wherein the lubricating oil pump is provided in the cylinder bore 2 for storing the distributor of 5A.