JPH04123355U - fuel circulation type carburetor - Google Patents

Abstract

(57) [Summary] [Purpose] To simplify the starting operation of a fuel circulation type carburetor and to improve starting performance. [Structure] A starting fuel chamber 30 that is independent from the fuel chamber 6 and connected to the intake passage 2 and a starting pump 23 that supplies fuel to the fuel chamber 6 prior to starting the engine are provided, and the fuel chamber 6 is provided with:
A fuel receiver 27 is provided to receive the fuel discharged from the starter pump 23 and reduce the force of the fuel flowing into the fuel chamber 6, and a guide path 39 captures the fuel that splashes up against the fuel receiver 27 and guides it to the starter fuel chamber 30. will be established.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention connects a fuel chamber and a fuel tank to a fuel supply passage and a retarder equipped with a fuel pump. The fuel pump supplies fuel to the fuel chamber during engine operation. At the same time, the fuel overflowing from the fuel chamber is returned to the fuel tank through the return passage. The present invention relates to a fuel circulation type carburetor which forms a constant oil level in a fuel chamber.

0002

[Conventional technology]

The above vaporizers are often installed in machines and vehicles that are used seasonally. Like seedling machines, rice transplanters, and rice harvesters, they operate for at most ten days a year, and the remaining If the product is left unused for most of the year, it may remain in the fuel chamber of the carburetor due to long-term storage. The quality of the fuel deteriorates. To prevent this, generally the bottom of the fuel chamber of the carburetor is A small hole is provided that communicates with the return passage, and a small amount of fuel is constantly discharged from this small hole. or run a wire from the fuel chamber to the return passage above the fuel chamber. so that a small amount of fuel is constantly expelled by the capillary action of this wire. The fuel chamber is automatically emptied after the engine stops, and the fuel chamber is automatically emptied when the engine is started next time. Prior to this, the fuel in the fuel tank is supplied to the fuel chamber using a manual pump. The fuel chamber is configured to be filled with fuel.

0003

[Problem that the invention attempts to solve]

On the other hand, in order to start the engine, it is necessary to enrich the mixture concentration, but fuel is not added to the fuel chamber. Even if the conditions are met, the amount of fuel supplied from the nozzle is set to suit the operating conditions after startup. Therefore, in order to supply the desired rich mixture to the engine, Furthermore, it is necessary to limit the amount of intake air by closing the choke valve, and the It is very troublesome to operate the choke valve after using the manual pump. Met. In addition, by closing the choke valve, it is possible to create a rich mixture that is optimal for starting. The driver needs a certain level of skill to achieve this, and beginners often make starting mistakes. There was a drawback.

0004 The present invention simplifies the starting operation of the fuel circulation type carburetor and improves startability. The purpose is to improve.

[0005]

[Technical means to solve problems]

The present invention provides a starting fuel chamber that is formed independently of the fuel chamber and connected to the intake passage. and a starting pump for supplying fuel to the fuel chamber prior to starting, the fuel The fuel chamber receives the fuel pumped from the starter pump and reduces the force of the fuel flowing into the fuel chamber. In addition to providing a fuel receptacle to spread the water, a fuel receptacle is provided to catch the fuel that splashes up when it hits this fuel receptacle. The invention is characterized in that a guide path is provided for guiding the fuel to the starting fuel chamber.

[0006]

[Effect]

When the starting pump is operated to supply fuel to the fuel chamber before starting the engine, the above Fuel pumped from the fuel pump hits the fuel receiver and flows into the fuel chamber. Also Some of the fuel splashed up in this fuel receiver is captured in the guideway and guided to the starting fuel chamber. entered. After the starting fuel chamber is filled with fuel, when the engine is cranked, it will be released from the nozzle. In addition to the fuel in the starting fuel chamber, the fuel in the starting fuel chamber is sucked in to produce a desired rich mixture. After the engine starts, the fuel in the starting fuel chamber is gradually consumed and warm-up operation progresses. go With this warm-up operation, the oil level in the starting fuel chamber gradually decreases. As a result, the air-fuel mixture concentration gradually decreases and warm-up is performed smoothly.

[0007]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of the vaporizer of the present invention, and FIG. 2 is a cross-sectional view taken along the line A--A in FIG.

[0008] Reference numeral 1 denotes a carburetor main body, and an intake passage 2 is provided to pass through the main body 1. The passage 2 is provided with a throttle valve 3 for varying the effective diameter of the intake passage 2. Applicable A jet needle 4 that protrudes downward is attached to the throttle valve 3, and its tip end is connected to the It is fitted into a fuel nozzle 5 that opens at the bottom wall of the intake passage 2 below the throttle valve 3. A fuel chamber 6 is provided below the carburetor main body 1. The fuel nozzle 5 is arranged to protrude downward from the fuel nozzle 5, and the lower end of the fuel nozzle 5 is It is communicated with the oil level below the fuel chamber 6 via the injector 7 .

[0009] 10 is a fuel pump driven by the operating pressure of the engine. This fuel pump 1 0 is a conventional pump consisting of a pump diaphragm 11 and a pair of check valves 12 and 13. This is a well-known diaphragm pump, with a pump diaphragm 11 formed on one side. The operating pressure of the engine is stored in the pressure chamber 14, for example crank chamber pressure in a two-stroke engine. By applying force, the pump diaphragm 11 is vibrated and the fuel is The pump is connected from the tank 15 through the fuel supply passage 18 and one check valve 12. Suction is drawn into the pump chamber 17 formed on the other side of the diaphragm 11, and the other check valve 1 3 and is discharged into the fuel chamber 6.

0010 A return passage 20 that opens to a specified oil level is provided on the side of the fuel chamber 6. The excess fuel fed from the fuel pump 10 flows through the return passage 20. The oil is then discharged to the fuel tank 15, and the oil level in the fuel chamber 6 is kept constant. Also, fuel Between the chamber 6 and the return passage, the fuel in the fuel chamber 6 is passed through the return passage by capillary action. A wire 21 is arranged to discharge a small amount of fuel into the return passage 20 at all times. I'm letting it come out. Therefore, after the engine is stopped, the fuel in the fuel chamber 6 is automatically discharged. It will be done.

[0011] 23 is a starting pump for supplying fuel to the fuel chamber 6 before starting. Ru. This starting pump 23 has, for example, a dome-shaped elastic body 24 that protrudes outside the carburetor. The inner chamber 25 of the elastic body and the pump chamber 17 of the fuel pump are communicated with each other. , by repeatedly pushing the elastic body 24, the fuel can be checked from the fuel tank 15. The fuel is sucked into the inner chamber 25 through the check valve 12 and discharged into the fuel chamber 6 through the check valve 13. It is something that can be done. Below the discharge port 26 of the starter pump, there is a fuel receiver above the oil level. A groove 27 is formed to temporarily transfer the fuel from the starter pump 23 to the fuel receiver 27. After applying the fuel, the fuel is allowed to flow into the fuel chamber 6 to prevent bubbles from being generated in the fuel.

0012 On the other hand, a starting fuel chamber 30 is installed on the side of the fuel chamber 6 independently from the fuel chamber 6. This starting fuel chamber 30 has a starting fuel chamber 30 whose upper end is connected to the starting mixture passage 31. A fuel pipe 32 for supplying the fuel in the fuel chamber 6 to the starting mixture passage 31 is arranged. are doing. This starting mixture passage 31 is connected to the intake passage 2 on the downstream side of the throttle valve 3, and is It is opened and closed by a starting valve 33 that is controlled dynamically or automatically. In addition, the starting fuel chamber 30 is connected to the fuel chamber 6 or the return passage by a passage 34 at the oil level of the chamber 30. 20, and after the starting fuel chamber 30 is filled with fuel, the fuel is discharged from the passage 34. The fuel is discharged into the fuel chamber 6 or the return passage 20 and a certain amount is delivered to the starting fuel chamber 30. of fuel is stored. 36 is provided in the starting fuel pipe 32. This is a bleed hole.

[0013] Further, a plate 38 is sandwiched between the carburetor main body 1 and the fuel chamber 6, and this plate The fuel discharged from the starter pump 23 is guided through a guide path 39 formed on the The fuel splashed up by hitting the receiver 27 is captured and guided to the starting fuel chamber 30. It has become.

[0014] The operation of the above embodiment will be explained below. If the starter pump 23 is pressed repeatedly before starting the engine, the fuel will be discharged from the fuel tank 15. Fuel is sucked in and discharged into the fuel chamber 6. This fuel once hits the fuel receiver 27. This prevents air bubbles from flowing into the fuel chamber 6 and from forming in the fuel. Also, the fuel Some of the fuel that splashed up after hitting the receiver 27 is captured in the guideway 39 and used as starting fuel. It is introduced into the chamber 30. Once the oil level in the starting fuel chamber 30 reaches the specified level, the The surplus is discharged through the passage 34 to the fuel chamber 6 or the return passage 20, and is stored in the fuel tank 1. Returned to 5.

[0015] Next, open the starting valve 33 manually or automatically, and start the engine with the throttle valve 4 closed. When cranking, the intake negative pressure acts on the starting mixture passage 31, and the starting fuel The fuel in the chamber 30 is mixed with air from the bleed hole 36 in the starting fuel pipe 32. It is sucked in. This starting mixture is a rich mixture together with the fuel from the fuel nozzle 5. and improves startability. After the engine starts, as the warm-up operation progresses, the fuel in the starting fuel chamber 30 increases. As the fuel is consumed, the mixture concentration gradually becomes thinner as the oil level decreases. Warm-up operation is performed smoothly. The fuel in the starting fuel chamber 30 is completely filled. Once consumed, fuel is supplied only from the fuel nozzle 5, and the normal mixture concentration is reduced. will be automatically migrated each time. Note that the starting pump 23 is not limited to the above embodiment, but may be any conventional one. It can also be implemented in other commonly used embodiments.

[0016] In the embodiments shown in FIGS. 3(A) and 3(B), the guide path 39 is integrated into the peripheral wall of the fuel chamber 6. The above plate 38 can be eliminated, reducing the cost of the carburetor. be able to.

[0017] In the embodiment of FIG. 4, the discharge port 36 of the starter pump 33 is different from the discharge port of the fuel pump 10. It is provided separately, and by configuring it in this way, it is possible to prevent The fuel splashed up in the fuel receiver 27 while the engine is running is stored in the starting fuel chamber. 30 can be reliably prevented, which is more desirable.

[0018]

[Effect of the idea]

As detailed above, according to the present invention, the intake passage is formed independently of the fuel chamber and a starting fuel chamber connected to the starting fuel chamber, and a starting fuel chamber for supplying fuel to the fuel chamber prior to starting. A pump is provided in the fuel chamber, and the fuel chamber is configured to receive fuel pumped from the starter pump. In addition to providing a fuel receiver to soften the force of fuel flowing into the A guide path is provided to capture the fuel that jumps up and guide it to the starting fuel chamber. When operating the dynamic pump, fuel is supplied to the fuel chamber and a certain amount of starting fuel is stored at the same time. By supplying this fuel when starting the engine, the fuel can be mixed. The air concentration can be increased and the starting operation becomes easier. In addition, during warm-up operation after starting As the starting fuel decreases, the air-fuel mixture concentration automatically decreases, so the engine warms up. The rotation is carried out smoothly.

[0019] In addition, it captures the fuel that splashes up against the fuel receiver and guides it to the starting fuel chamber. The starting pump, such as when fuel from the starting pump is discharged directly into the starting fuel chamber. The force of the fuel is injected into the starting mixture passage through the starting pipe, and the engine starts. Problems that lead to defects are eliminated.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1.

FIG. 3(A) is a top view of a fuel chamber showing another embodiment of the present invention.

FIG. 3(B) is a sectional view taken along line BB in FIG. 3(A).

FIG. 4 is a longitudinal sectional view showing another embodiment of the present invention.

[Explanation of symbols]

1 Vaporizer body 2 Intake path 6 Fuel chamber 20 Return passage 23 Starting pump 27 Fuel receiver 30 Starting fuel chamber 39 Guidance route

Claims (1)

[Scope of utility model registration request] Claim 1: A fuel chamber and a fuel tank are connected by a fuel supply passage and a return passage provided with a fuel pump, and when the engine is operated, the fuel pump supplies fuel to the fuel chamber and prevents fuel overflowing from the fuel chamber. In the fuel circulation type carburetor, a constant oil level is formed in the fuel chamber by returning oil to the fuel tank through the return passage, and a starting fuel chamber is formed independently from the fuel chamber and is connected to the intake passage. a starting pump that supplies fuel to the fuel chamber prior to starting; a fuel receiver that receives fuel pumped from the starting pump and reduces the force of the fuel flowing into the fuel chamber; A fuel circulation type carburetor characterized in that a guide path is provided to capture the fuel that splashes up against the fuel receiver and guide it to the starting fuel chamber.