WO2020220728A1

WO2020220728A1 - Fuel inlet structure of two-stroke gasoline engine

Info

Publication number: WO2020220728A1
Application number: PCT/CN2020/070022
Authority: WO
Inventors: 黄新跃; 金传信
Original assignee: 浙江中马园林机器股份有限公司
Priority date: 2019-04-30
Filing date: 2020-01-02
Publication date: 2020-11-05
Also published as: CN110005556A; CN110005556B

Abstract

A fuel inlet structure of a two-stroke gasoline engine, comprising a carburetor (1), a fuel tank (2) and a fuel inlet pipe (3). The fuel inlet pipe (3) has one end connected to the carburetor (1) in a sealed manner, and the other end inserted into the fuel tank (2) and extending to the bottom of the fuel tank (2), a gasoline filter (4) is connected to a fuel inlet end of the fuel inlet pipe (3), a lateral branch connection port (5) is provided on one side of the outer circumferential surface of the fuel inlet pipe, and the branch connection port (5) is in communication with the fuel inlet pipe (3), the branch connection port (5) is located in the fuel tank (2) and is close to the top of the fuel tank (2), the branch connection port (5) is provided with a pressure relief valve (6), and the pressure relief valve (6) is a one-way valve enabling only one-way entry, into the fuel tank, of air in the fuel inlet pipe. A vapor lock formed by the high-temperature high-pressure gas in the carburetor and the fuel inlet pipe after the shutdown of the gasoline engine can be discharged, through the pressure relief valve, into the environment of the fuel tank in communication with the atmosphere, improving the probability of normal starting of the gasoline engine after shutdown.

Description

Oil intake structure of two-stroke gasoline engine

Technical field

The invention belongs to the technical field of gasoline engines, and relates to an oil intake structure of a two-stroke gasoline engine.

Background technique

The upper end of the oil inlet pipe of the current two-stroke gasoline engine carburetor is connected to the carburetor copper pipe, the lower end is plugged into the fuel filter, the oil inlet pipe is soaked in the fuel tank, and the middle part is stuck on the fuel tank shell. The carburetor will receive the high-frequency negative pressure pulse from the crankcase. This pulse will vacuum the carburetor and its connected fuel inlet pipe, forcing the fuel to flow up into the carburetor, and then the carburetor will eject the oil. Fog, together with the incoming air, participates in the combustion work of the gasoline engine; after the gasoline engine is stopped, the temperature is very high, and the gasoline engine is difficult to restart. The reason is that the high temperature components such as the cylinder will radiate heat from the carburetor and the fuel inlet pipe, and high temperature will be formed in the fuel inlet pipe. The high-pressure air resistance prevents the oil inlet pipe from entering oil. The gasoline engine can only be started normally after the temperature of the carburetor and the oil inlet pipe drops. The air resistance in the oil inlet pipe at high temperatures makes it difficult to start the gasoline engine, which is a cause for people’s production and life. It was a great inconvenience.

Summary of the invention

In view of the above-mentioned problems existing in the prior art, the present invention provides an oil intake structure for a two-stroke gasoline engine. The technical problem to be solved by the present invention is how to improve the normal starting probability of the gasoline engine in a high temperature environment after shutdown.

The purpose of the present invention can be achieved through the following technical solutions:

A fuel intake structure for a two-stroke gasoline engine, comprising a carburetor, a fuel tank, and a hollow fuel intake pipe. One end of the fuel intake pipe is sealed to the carburetor, and the other end is inserted into the fuel tank and extends To the bottom of the fuel tank, the fuel inlet end of the fuel inlet pipe is also provided with a fuel filter connected to the fuel inlet of the fuel inlet pipe; characterized in that, one side of the outer peripheral surface of the fuel inlet pipe is provided A horizontal branch interface and the branch interface communicates with the fuel inlet pipe, the branch interface is located in the fuel tank and is close to the top of the fuel tank, and the branch interface is provided with a pressure relief valve. The valve is a one-way valve capable of and only allowing the air in the fuel inlet pipe to enter the fuel tank in one direction.

Its working principle is as follows: one end of the fuel inlet pipe in this technical solution is connected to the carburetor in a sealed manner, and the other end extends into the fuel of the fuel tank and is connected with the fuel filter, so that a closed environment is formed in the fuel inlet pipe, and the temperature is high after shutdown. The lower carburetor and the fuel inlet pipe are easy to form air resistance. The fuel inlet pipe is located above the fuel in the fuel tank and near the upper part of the fuel tank is equipped with a pressure relief valve. The pressure relief valve is a one-way valve, which can control the high temperature and high pressure in the fuel inlet pipe. The hot air is discharged into the atmosphere in the fuel tank through the pressure relief valve, so that the air pressure inside and outside the fuel inlet pipe is balanced, so that the air resistance in the fuel inlet pipe and the carburetor disappears. At this time, the air resistance makes the fuel filter The oil inlet hole of the closed filter element can also be opened to allow fuel to enter the oil inlet pipe, which makes it easier to start the gasoline engine, which increases the chance of the gasoline engine starting normally at high temperatures; when the oil engine is working normally, the oil inlet pipe will form first Vacuum. At this time, the inside of the pressure relief valve also forms a vacuum. The end of the pressure relief valve exhausted to the fuel tank will be flattened by the outside atmospheric pressure and completely closed.

In the above-mentioned two-stroke gasoline engine oil intake structure, the branch interface has a mounting hole, one end of the pressure relief valve is located in the branch interface, and the other end extends out of the branch interface and is located in the fuel tank Inside. The installation hole is provided in the branch interface to facilitate the installation of the pressure relief valve. One end of the pressure relief valve is connected with the oil inlet pipe in the branch interface, and the other end is in the environment where the fuel tank is open to the atmosphere, which facilitates exhaust and eliminates air resistance.

In the above-mentioned oil intake structure of a two-stroke gasoline engine, a vent hole extending to the inner wall of the oil intake pipe is opened in the branch interface, and the pressure relief valve is opened along its central axis with a vent that is connected to the vent hole.压孔. The branch interface is provided with a vent hole and a pressure relief hole opened in the pressure relief valve to discharge the high temperature and high pressure gas in the oil inlet pipe.

In the above-mentioned two-stroke gasoline engine oil intake structure, the end of the inner end of the pressure relief valve is spherical and abuts against the end of the vent hole, and the pressure relief hole is located at the inner end of the pressure relief valve. The port is an opening, the diameter of the pressure relief hole gradually decreases from the end of the branch interface to the outer end of the pressure relief valve, and the port of the pressure relief hole located at the outer end of the pressure relief valve is a constriction . The end of the inner end of the pressure relief valve is spherical in order to squeeze the inner wall of the installation hole of the branch interface, so that the pressure relief valve is connected to the branch interface in a sealed manner. The opening of one end of the pressure relief valve is connected with the end of the vent hole, and the other end It is designed to be constricted and located in the fuel to facilitate the discharge of the pressure relief valve and prevent the pressure relief valve from leaking when the gasoline engine is working normally.

In the above-mentioned two-stroke gasoline engine oil intake structure, the diameter of the opening on the pressure relief valve is smaller than the diameter of the vent hole. It is convenient to increase the discharge speed of hot air in the oil inlet pipe.

In the above-mentioned oil intake structure of the two-stroke gasoline engine, the oil intake pipe and the pressure relief valve are made of oil-resistant nitrile rubber. After the pressure relief valve and the branch interface on the oil inlet pipe are inverted and press-fitted, the tightness of the two is guaranteed

Compared with the prior art, the present invention has the following advantages:

1. The fuel inlet pipe of the present invention is provided with a branch interface, and a pressure relief valve that is a one-way valve is sealed in the branch interface, which can discharge the high temperature and high pressure hot air in the fuel inlet pipe through the pressure relief valve, so that the gasoline engine is at a high temperature after shutdown. The probability of successful start-up is improved.

2. One end of the pressure relief valve in the present invention located in the branch interface is spherical, and the oil inlet pipe and the pressure relief valve are made of oil-resistant nitrile rubber, which can provide a guarantee for the tightness between the pressure relief valve and the branch interface.

3. In the present invention, the opening diameter of one end of the pressure relief valve is smaller than the diameter of the vent hole of the branch interface and the other end of the pressure relief valve is a contraction, so that the flow rate of the hot air in the intake pipe to the pressure relief valve is increased, which is convenient for the hot air Quickly discharge.

Description of the drawings

Figure 1 is a schematic structural diagram of the oil intake structure in the two-stroke gasoline engine and a partial enlarged structural diagram of the pressure relief valve in the oil intake structure at a high temperature after shutdown.

In the figure, 1. Carburettor; 2. Fuel tank; 3. Fuel inlet pipe; 4. Fuel filter; 5. Branch interface; 51. Mounting hole; 52. Vent hole; 6. Pressure relief valve; 61. Pressure relief hole ; 61a, opening; 61b, necking.

Detailed ways

The following are specific embodiments of the present invention combined with the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

As shown in Figure 1, the fuel inlet structure of the two-stroke gasoline engine in this embodiment includes a carburetor 1, a fuel tank 2 and a hollow fuel inlet pipe 3. One end of the fuel inlet pipe 3 is inserted into the carburetor 1, and the other end Inserted into the fuel tank 2 and fixedly connected with the fuel filter 4, the fuel inlet pipe 3 is located near the upper end of the inner wall of the fuel tank 2 with a horizontal branch interface 5, and the branch interface 5 is provided with a mounting hole 51 and communicates with the inner wall of the fuel inlet pipe 3. A pressure relief valve 6 is inserted into the mounting hole 51. The pressure relief valve 6 has a pressure relief hole 61 along its central axis. The pressure relief hole 61 is opposite to the vent hole 52 in the branch interface 5 to relieve pressure. One end of the valve is located in the mounting hole 51 on the branch interface 5 and the other end is located in the fuel tank 2 outside the branch interface 5. The pressure relief valve 6 is a single valve that can only discharge the hot air in the fuel inlet pipe 3 into the fuel tank 2. In this way, the air pressure inside and outside the oil inlet pipe 3 can be balanced, and the probability of successful startup of the gasoline engine under high temperature conditions after shutdown is increased.

The oil inlet pipe 3 and the pressure relief valve 6 are made of oil-resistant nitrile rubber. One end of the pressure relief valve 6 is spherical, and the pressure relief hole 61 is located at one end of the pressure relief valve 6 and the port is an opening 61a. 6 The hole diameter of the opening 61a is smaller than the hole diameter of the vent hole 52 of the branch interface 5. The hole diameter of the pressure relief hole 61 gradually decreases from the end of the branch interface 5 to the other end of the pressure relief valve 6. The pressure relief hole 61 is located in the pressure relief valve 6. The port at the other end is a constriction 61b. The pressure relief valve 6 and the oil inlet pipe 3 are made of the same material and have elasticity, which facilitates the sealed connection of the two. The pressure relief valve 6 is located in a part of the installation hole 51 on the branch interface 5 and is set in a spherical shape. , Which provides a guarantee for the sealing connection between the pressure relief valve 6 and the fuel inlet pipe 3. When the air pressure in the fuel inlet pipe 3 rises and is higher than the atmospheric pressure in the fuel tank 2, the high pressure inside the fuel inlet pipe 3 will open the relief valve 6 , The high-pressure air is discharged. After the air pressure inside and outside the oil inlet pipe 3 is balanced, the drain valve 6 is closed. When the gasoline engine just starts to run, the oil inlet pipe 3 will form a vacuum. When the oil inlet pipe 3 has negative pressure, the pressure relief valve 6 will also close tighter due to the negative pressure.

The specific embodiments described herein are merely examples to illustrate the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or additions to the specific embodiments described or use similar alternatives, but they will not deviate from the spirit of the present invention or exceed the definition of the appended claims. Range.

Claims

An oil intake structure of a two-stroke gasoline engine, comprising a carburetor (1), a fuel tank (2) and a hollow oil intake pipe (3), one end of the oil intake pipe (3) and the carburetor (1) In a sealed connection, the other end is inserted into the fuel tank (2) and extends toward the bottom of the fuel tank (2), and the fuel inlet end of the fuel inlet pipe (3) is also provided with the fuel inlet pipe ( 3) the fuel filter (4) connected to the fuel inlet; characterized in that, one side of the outer peripheral surface of the fuel inlet pipe (3) is provided with a lateral branch interface (5) and the branch interface (5) is connected to the The fuel inlet pipe (3) is connected, the branch interface (5) is located in the fuel tank (2) and close to the top of the fuel tank (2), and the branch interface (5) is provided with a pressure relief valve (6) The pressure relief valve (6) is a one-way valve that can and can only make the air in the oil inlet pipe (3) enter the fuel tank (2) in one direction.
The oil intake structure of a two-stroke gasoline engine according to claim 1, wherein the branch interface (5) has a mounting hole (51), and one end of the pressure relief valve (6) is located at the branch interface ( 5), the other end extends out of the branch interface (5) and is located in the fuel tank (2).
The oil intake structure of a two-stroke gasoline engine according to claim 1 or 2, wherein the branch interface (5) is provided with a vent hole (52) extending to the inner wall of the oil intake pipe (3), and The pressure relief valve (6) has a pressure relief hole (61) butted with the vent hole (52) along its central axis.
The oil intake structure of a two-stroke gasoline engine according to claim 3, characterized in that the end of the inner end of the pressure relief valve (6) is spherical and abuts against the end of the vent hole (52), The port of the pressure relief hole (61) at the inner end of the pressure relief valve (6) is an opening (61a), and the diameter of the pressure relief hole (61) ranges from the end of the branch interface (5) to the The outer end of the pressure relief valve (6) gradually becomes smaller, and the port of the pressure relief hole (61) at the outer end of the pressure relief valve (6) is a constriction (61b).
The oil intake structure of a two-stroke gasoline engine according to claim 4, characterized in that the diameter of the opening (61a) on the pressure relief valve (6) is smaller than the diameter of the vent hole (52).
The oil intake structure of a two-stroke gasoline engine according to claim 5, wherein the oil intake pipe (3) and the pressure relief valve (6) are made of oil-resistant nitrile rubber.