JPH0424133Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention connects the fuel chamber of a carburetor and the fuel tank with a fuel supply passage and a return passage equipped with a fuel pump, and the fuel chamber is supplied to the fuel chamber by the fuel pump. The present invention relates to a fuel circulation type carburetor that supplies fuel and returns fuel overflowing from the fuel chamber to the fuel tank through the return passage.

(Prior art) Generally, general-purpose engines equipped with fuel circulation type carburetors are often installed in machines and vehicles that are used seasonally, such as seedling machines, rice transplanters, and rice harvesters. If the carburetor is operated for at most ten or more days and then left unused for most of the rest of the year, the fuel remaining in the fuel chamber of the carburetor will deteriorate due to long-term storage.

In order to prevent this, conventionally, a small hole is formed at the bottom of the fuel chamber to communicate the fuel chamber and the return passage.
A structure has been proposed in which a small amount of fuel always flows out from the small hole, so that no fuel remains in the fuel chamber after the engine is stopped.

(Problems with the prior art) However, in the above-mentioned fuel circulation type carburetor, if the small holes are blocked by debris that settles in the fuel chamber, the fuel in the fuel chamber will not be discharged, and as a result, the fuel will remain in the fuel chamber. The problem was that the fuel remained in the tank and the quality of the fuel deteriorated.

(Means for solving the problem) In order to solve the above problem, the present invention communicates the fuel chamber and the return passage of the fuel circulation type vaporizer through two holes, a large hole and a small hole, and connects the large hole to the return passage. A drain screw is installed to open and close the hole.

(Specific Embodiment of the Present Invention) Hereinafter, a specific embodiment of the present invention will be explained based on FIG. 1 and FIG.
is an intake passage, 3 is a throttle valve, 4 is a fuel chamber, and 5 is a return passage formed on the side of the fuel chamber 4, the upper end of which opens to the specified oil level in the fuel chamber 4, and the lower end to the fuel tank. 6 via the connection port 7 to the fuel tank 6
connected to. 8 is a fuel supply port that opens into the fuel chamber 4; 9 is a fuel supply passage that connects the fuel supply port 8 and the fuel tank 6; 10 is disposed in the middle of the fuel supply passage 9, and is activated only when the engine is operating. a fuel pump, 11 is a large hole that communicates the bottom of the fuel chamber 4 with the return passage 5; 12 is a screw hole provided in a side wall of the return passage 5 at a position opposite to the large hole 11; 13 is a screw hole provided in the screw hole 12; It is a drain screw that is screwed on, and the drain screw 13 is screwed on.
The tip 14 crosses the return passage 5 and abuts the large hole 11. A small hole 15 is provided in the projected plane of the screw hole 12 and communicates the fuel chamber 4 with the return passage 5.

In a fuel circulation type carburetor having such a structure, the large hole 11 is normally closed by the drain screw 13, and the fuel in the fuel chamber 4 flows through the small hole 15.
It is constantly emitted from the chisel. Furthermore, during engine operation, a much larger amount of fuel flows into the fuel chamber 4 by the fuel pump 10 than the amount of fuel flowing out from the small hole 15, so that the fuel chamber 4 is filled with fuel and does not overflow. By returning the fuel from the return passage 5 to the fuel tank 6, a specified oil level is formed in the fuel chamber 4. When the engine is stopped, the fuel pump 10 stops supplying fuel, so that the fuel in the fuel chamber 4 is reduced. is gradually discharged into the fuel tank 6 through the return passage 5 through the small hole 15.

In addition, if the small hole 15 is clogged with dirt or the like, the drain screw 13 is rotated to open the large hole 11 and the fuel is discharged from the screw hole 12 of the drain screw 13. The small hole 15 can be cleaned.

FIG. 3 is a vertical cross-sectional view of a main part showing another embodiment of the present invention, in which the small hole 15 is connected to the drain screw 13.
It was established in

The presence or absence of fuel in the fuel chamber 4 can be confirmed by providing a transparent window (not shown) on the side of the fuel chamber 4, or by
Alternatively, the fuel chamber 4 may be formed of transparent synthetic resin or the like.

(Effects of the invention) As detailed above, according to the invention, the fuel chamber of the fuel circulation type carburetor is provided with a small hole that constantly discharges a small amount of fuel and a large hole that is opened and closed by a drain screw. Since the fuel in the fuel chamber can be reliably discharged, there is no need to leave gasoline remaining in the fuel chamber, and corrosion and rust in the fuel chamber due to deterioration of gasoline can be prevented.

In addition, if the small hole becomes clogged with dirt, the small hole can be cleaned by removing the drain screw or through the screw hole of the drain screw, making maintenance easier and improving the performance of the vaporizer. can be kept.

In addition, if the tip of the drain screw is tapered so that the opening degree of the large hole can be adjusted, the drain screw can be used to adjust the normal fuel outflow amount, so that it can be used in various ways. It is possible to obtain a fuel outflow amount that matches the fuel consumption of the engine.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention;
The figure is a view taken along the line A--A in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view of a main part showing another embodiment of the present invention. 1... Carburetor body, 4... Fuel chamber, 5... Return passage, 6... Fuel tank, 8... Fuel supply port, 9... Fuel supply passage, 10... Fuel pump,
11...Large hole, 13...Drain screw, 15
...Small hole.

Claims (1)

[Scope of utility model registration request] The fuel chamber and the fuel tank are connected by a fuel supply passage and a return passage provided with a fuel pump, the fuel pump supplies fuel into the fuel chamber, and the fuel overflowing from the fuel chamber is transferred to the fuel tank through the return passage. In a fuel circulation type carburetor configured to return fuel, the fuel chamber and the return passage communicate with each other through a large hole, and the opening and closing of the large hole is controlled by a drain screw installed across the return passage from outside the carburetor, The fuel circulation type carburetor is further characterized in that a small hole communicating the fuel chamber and the return passage is provided in the projected plane of the screw hole of the drain screw.