JPS649444B2 - - Google Patents

Abstract

PURPOSE:To reduce the consumption of lubricating oil and surely prevent seizure or the like, by decreasing the lubricating oil supply at the slow rotation of an engine and supplying a necessary quantity of lubricating oil at the rapid rotation. CONSTITUTION:When the revolution speed of an engine (a) is low, a valve 12 which opens or closes in response to the revolution speed opens to enable communication through a second passage 7 so that lubricating oil conducted by a pump 4 is divided into the second passages 6, 7. Since the lubricating oil passed through the second passage 7 is collected in a reservoir 8, the lubricating oil supply to the engine (a) is reduced by half. Because the negative pressure of an intake passae 1 acts to the reservoir 8 in that case, a one-way valve 11 is closed by the pressure difference between the reservoir and a lubricating oil tank 5 to restrict the flow of the lubricating oil to the tank 5 from the reservoir 8. When the revolution speed of the engine (a) is high, the valve 12 closes so that the lubticating oil conducted by the pump 4 is all supplied to the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lubricating oil supply device for a two-stroke engine.

(Prior art) Conventionally, as shown in Japanese Patent Publication No. 52-38180, this type of device supplies lubricating oil from a lubricating oil tank provided separately from the fuel tank to the engine via an oil supply valve. There is something I tried to do.

However, the above-mentioned device has a complicated structure because the amount of oil supplied is adjusted to the engine speed by adjusting the opening and closing time of the oil supply valve using a control device in accordance with the engine speed. However, there was a problem that it was expensive.

(Problems to be Solved by the Present Invention) An object of the present invention is to provide a lubricating oil supply device for a two-stroke engine that can achieve optimization of the lubricating oil supply amount with a simple structure and at low cost.

(Means for Solving the Problems) In order to solve the above-mentioned problems, a lubricating oil supply device for a two-stroke engine according to the present invention includes a lubricating oil pump whose discharge amount increases and decreases in proportion to the rotational speed of the engine, A first passage connecting the air intake passage to the engine, and a second passage branching off from the middle of the passage.
and a second passage provided downstream of this second passage.
A storage part with a predetermined capacity for storing lubricating oil from the passage, and the storage part and the intake passage are connected, and the connection end on the intake passage side is connected to the first passage and the carburetor in the intake passage. A communication passage connected to either the upstream side or the downstream side, a valve provided in the middle of the second passage that opens the passage when the engine rotation speed is low and closes when the rotation speed of the engine exceeds a predetermined speed; A lubricating oil tank is connected to the lubricating oil tank via a valved connection path and communicating with the suction side of the lubricating oil pump.

(Example) An example of carrying out the present invention will be described with reference to the drawings. In the drawing, a indicates a two-stroke engine, and 1 indicates an intake passage connected to an intake hole of the engine a.

2 is an air cleaner provided upstream of the intake passage 1, and 3 is a carburetor provided downstream of the air cleaner 2. Reference numeral 4 designates a lubricating oil pump, whose suction side is connected to a lubricating oil tank 5, and its discharge side is connected to the intake passage 1 via a first passage 6, which will be described later.

The pump 4 has a discharge amount that increases or decreases in proportion to the rotational speed of the engine a.

For example, the drive unit of the pump 4 is connected to the engine a via a reduction gear device.

The pump 4 may be of a plunger type or of any other type, but if a plunger type is used, the discharge amount can be adjusted by linking the stroke amount of the plunger with the throttle opening. can be increased or decreased in proportion to not only the rotational speed of engine a but also the throttle opening.

On the other hand, the first passage 6 is connected downstream of the carburetor 3 in the intake passage 1, and supplies the lubricating oil discharged from the pump 4 to the engine a through the intake passage 1.

7 is a second passage branching from the middle of the first passage 6;
The lubricating oil from the pump 4 is distributed to both the passages 6 and 7.

Reference numeral 8 denotes a storage section provided downstream of the second passage 7, in which the lubricating oil flowing through the second passage 7 is temporarily stored.

This storage portion 8 is connected to the intake passage 1 downstream of the carburetor 3 via a communication passage 9, and negative pressure from the passage 1 acts thereon.

That is, by applying the negative pressure in the intake passage 1 to the second passage 7 as well as to the first passage 6, lubricating oil is made to flow almost equally to both passages 6, 7.

Note that there is also a pressure difference in the intake passage 1 between the upstream side and the downstream side of the carburetor 3.

Therefore, by connecting both the above-described communication passage 9 and the first passage 6 to either the downstream side or the upstream side of the carburetor 3 in the intake passage 1, the same negative pressure can be applied to both passages 9 and 6. It is made to work.

The storage portion 8 has a capacity that prevents the inflowing lubricating oil from overflowing even if the engine a is continuously operated until the fuel is emptied, and the communication path 9 is connected to the storage portion 8.
By connecting it to a sufficiently high position, the lubricating oil stored in the reservoir 8 is prevented from flowing into the communication path 9.

Further, the reservoir 8 is connected to a lubricating oil tank 5 through a connecting path 10 at its bottom, and the tank 5 is arranged below the reservoir 8.

Reference numeral 11 denotes a one-way valve provided in the connection path 10, which allows lubricating oil to flow from the reservoir 8 to the lubricating oil tank 5, and prohibits lubricating oil from flowing from the lubricating oil tank 5 to the reservoir 8. I'll do what I do.

Reference numeral 12 denotes a valve provided in the middle of the second passage 7, which opens the passage 7 when the rotational speed of the engine a is low, and closes it when the rotational speed of the engine a reaches a predetermined speed or higher.

That is, the valve 112 is a so-called opening/closing valve, for example, a solenoid valve is used, and is electrically opened/closed when it detects that the rotational speed of the engine a has become above or below a set speed. .

Therefore, when the rotation speed of engine a is low during operation of the lubricating oil supply device, the second lubricating oil supply device
The valve 12 of the passage 7 opens to open the passage 7.

Therefore, the lubricating oil pumped from the pump 4 is
However, since the lubricating oil passing through the second passage 7 is stored in the reservoir 8, the lubricating oil supplied to the engine a is divided into the first passage 6. The amount of supply will be reduced by almost half compared to before.

Note that even if the supply amount of lubricating oil is halved, the rotational speed of engine a is low, so the amount of lubricating oil is sufficient to lubricate engine a.

Further, the lubricating oil stored in the storage portion 8 does not flow into the lubricating oil tank 5 but remains there.

That is, when the engine a is operating, the reservoir 8
Negative pressure from the intake passage 1 is acting on the lubricating oil tank 5, whereas the pressure inside the lubricating oil tank 5 is at atmospheric pressure, so the one-way valve 11 in the connecting passage 10 is closed due to the pressure difference between the two. , the flow of lubricating oil from the reservoir 8 to the lubricating oil tank 5 is regulated.

On the other hand, when the rotational speed of the engine a becomes higher than a predetermined speed, the valve 12 closes and the second passage 7 is closed.

Therefore, the lubricating oil from the pump 4 flows into the first passage 6.
The amount of lubricating oil supplied is more than double that of the case where the rotational speed of the engine a is low.

In this case, the amount of lubricant supplied is the same as before,
This is a necessary and sufficient amount for engine a.

That is, the discharge amount of the pump 4 is set in the same manner as in the conventional pump, and excess lubricating oil flows to the second passage 7 only when the rotational speed of the engine a is low.

In addition, when the engine a stops, the storage part 8
Since negative pressure no longer acts on the reservoir 8 and the lubricating oil tank 5, the pressure difference between the reservoir 8 and the lubricating oil tank 5 disappears, and the one-way valve 11 of the connecting passage 10 opens due to the weight of the lubricating oil in the reservoir 8.
Lubricating oil flows into the lubricating oil tank 5.

(Effects of the Invention) As described above, the present invention opens the valve in the second passage when the rotational speed of the engine exceeds a predetermined rotational speed,
In addition, by closing the valve when the engine rotational speed falls below a predetermined rotational speed, the amount of lubricating oil supplied to the engine is increased or decreased at a ratio of approximately 1:2. Since the amount of lubricating oil used during high-speed operation and low-speed operation is approximately appropriate, the structure is simpler than conventional ones, and manufacturing costs can be significantly reduced. .

As a result, the amount of lubricating oil supplied can be optimized with a simple structure and at low cost, and the desired objective can be achieved.

[Brief explanation of drawings]

The drawing is an explanatory view showing the device of the present invention. In the figure, a...2-cycle engine, 1...Intake passage, 4...Lubricating oil pump, 5...Lubricating oil tank, 6...
First passage, 7... Second passage, 8... Reservoir, 9...
Communication path, 10...Connection path, 11...Valve (connection path), 1
2...Valve (second passage).

Claims (1)

[Claims] 1. A lubricating oil pump whose discharge amount increases or decreases in proportion to the rotational speed of the engine, a first passage connecting this pump and an intake passage to the engine, a second passage branching off from the middle of the passage, and this A storage section with a predetermined capacity provided downstream of the second passage and storing lubricating oil from the second passage, and the storage section and the intake passage are connected, and the connecting end on the intake passage side is connected to the first passage. Along with that, there is a communication passage connected to either the upstream side or the downstream side of the carburetor in the intake passage, and a second passage is provided in the middle of the intake passage, and the passage is opened when the engine rotational speed is low, and when the rotational speed of the engine is at a predetermined speed or higher. A lubricating oil supply for a two-stroke engine, which is provided with a valve that closes when Device.