JP2583432B2 - Starter for vaporizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carburetor for controlling the concentration and amount of an air-fuel mixture supplied to an engine, and more particularly to a carburetor for supplying a rich air-fuel mixture when the engine is started. The starting device.

[Conventional technology]

Conventionally, a starting device for a carburetor for a two-cycle engine, which is generally used, has a choke valve disposed in an intake passage of the carburetor, and the intake passage is fully closed by the choke valve when the engine is started. A start passage connects the front and rear of a choke type and a throttle valve arranged in the intake passage with a start passage, and a starter opening / closing valve is arranged in the start passage, and when the engine is started, the start passage is kept open by the starter opening / closing valve. There is a so-called starter type.

[Problems to be solved by the invention]

 Such a conventional starting device has the following problems.

That is, according to the former, when the engine is cranked by closing the choke valve at the time of starting, the intake passage negative pressure generated by this cranking is increased by the choke effect of the choke valve, and the low-speed injection hole opened into the intake passage. In this configuration, the negative pressure of the intake passage acts on the injection holes of the main nozzle and the like to suck the fuel from the injection holes and supply the starting fuel to the engine. The fuel system or the main fuel system leading to the main nozzle is set so as to conform to the low-speed operation state of the engine, or the medium and high-speed operation states, respectively. In order to make adjustments, a lot of time is spent on setting work for the adjustment.

That is, when the low-speed fuel system or the main fuel system that has been set is changed to improve the starting performance, it is necessary to conduct a test of the low-speed fuel system and the main fuel system again to confirm them.

According to the latter, since the low-speed fuel system and the main fuel system have a start passage as a completely separate system, there is no connection between the low-speed fuel system and the main fuel system as in the former, and the setting work is easy, but the engine When the throttle valve is opened at the time of starting, it is difficult to obtain a high intake passage negative pressure in the intake passage, so that the starting fuel cannot be sucked out and the startability may be deteriorated.

[Means to solve the problem]

In view of the above-mentioned problems, the starting device for a carburetor according to the present invention is capable of easily performing setting work for improving startability and supplying optimum starting fuel for initial explosion, complete explosion and warm-up operation of the engine. In order to achieve the above object, the intake passage 2 penetrates the inside to achieve the above object, and to maintain the stable performance over a long period of time. In a vaporizer in which a float chamber main body 3 is arranged on a side portion of the vessel main body 1 and a float chamber 4 for storing a constant liquid level is formed by the vaporizer main body 1 and the float chamber main body 3; The starting fuel pump chamber 21 is divided into a starting fuel pump chamber 21 and an atmosphere chamber 22. The starting fuel pump chamber 21 is provided with a suction-side check valve 25 therein, and the starting fuel is communicated below a certain liquid level in the float chamber 4. Opening the inflow passage 24 and the starting fuel discharge passage 28 in which the discharge-side check valve 31 is disposed, Further, the partitioning body 20 pressed toward the starting fuel pump chamber 21 by the spring 37 has an opening / closing valve portion 33 that can control opening and closing of the starting fuel discharge passage, and an operation that can apply a pump operating force to the partitioning body 20. A first state in which the starting fuel discharge passage 28 is closed by the open / close valve portion 33 of the partition 20 and the partition 20 are pulled toward the atmosphere chamber 22 while the operating rod is provided integrally with the operating rod. An intermediate position regulating member N which can be held at a substantially intermediate position with respect to the second state is provided, and when the attraction to the operating rod 34 is released from the second state, the partition 20 is automatically returned to the substantially intermediate position by the spring force of the spring 37. This is a carburetor starting device that discharges fuel in the starting fuel pump chamber 21 through a starting fuel discharge passage 28.

[Action]

When the engine is started, the operation rod is pulled toward the atmosphere chamber to increase the capacity of the starting fuel pump chamber and the chamber, and the fuel in the floating chamber is sucked into the starting fuel pump chamber.

Next, the attraction to the operating rod is released to bring the operating rod into a free state. Then, the operating rod automatically moves toward the starting fuel pump chamber by the spring force of the spring, and the movement of the operating rod toward the starting fuel pump chamber is determined by the intermediate position regulating member.

According to this, the fuel in the starting fuel pump chamber is ejected and supplied from the starting fuel discharge passage into the intake passage to be ready for the first explosion and the complete explosion of the engine. When the engine is started in this state and the engine completes explosion and enters a warm-up operation, the negative pressure generated in the intake pipe opens the discharge-side check valve and warms up the start-up fuel discharge passage into the intake pipe. Supply fuel for the engine to satisfy the warm-up operation of the engine.

Next, when the warming-up operation is completed, a pressing force is applied to the operating rod to return the operating rod further to the starting fuel pump chamber side. According to this, since the opening / closing valve unit closes the starting fuel discharge path,
The supply of the starting fuel to the engine from the starting fuel discharge path is stopped.

During operation of the engine, even if the discharge-side check valve is opened, the on-off valve portion is sucked into the valve seat and closes the starting fuel discharge passage that opens inside the valve seat. Therefore, the negative pressure in the intake passage does not act to deform the partition.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

1, an intake passage 2 penetrates the inside, and a float chamber main body 3 is disposed on a side portion of the vaporizer main body 1, and a float chamber 4 is formed by the lower concave portion of the vaporizer main body 1 and the float chamber main body 3. You. 5
Is a valve seat that communicates with the fuel inlet H and opens into the float chamber 4. A float valve 6 is movably arranged corresponding to the valve seat 5, and the float valve 6 is further arranged in the float chamber 4. Thus, the float 9 rotatably supported by the pin 8 by the float arm 7 is arranged corresponding to the float arm 7. Then, the float arm 7 is turned by the rotation of the float 9 with respect to the pin 8,
The opening and closing of the valve seat 5 is controlled by the float valve 6.

Reference numeral 10 denotes a main nozzle as a main fuel system, the tip of which protrudes into the intake passage 2 and is opened, and the other end is disposed below a certain liquid level XX formed in the float chamber 4. Connects to main fuel jet 11. Reference numeral 12 denotes a throttle valve for controlling the opening and closing of the intake passage 2.

The above structure is a conventionally known technique, and the starting device of the vaporizer according to the present invention is as follows to achieve the above object.

That is, reference numeral 20 denotes a partition such as a diaphragm which is separated from the float chamber 4 and divides the inside into a starting fuel pump chamber 21 and an atmosphere chamber 22. Specifically, the starting fuel pump chamber 21 is a partition
The air chamber 22 is formed by the partition 20 and the cover 23. Note that J is an atmospheric hole that communicates the atmosphere chamber 22 with the atmosphere.

The following route is opened in the starting fuel pump chamber 21. That is, 24 has a suction-side check valve 25 inside,
The starting fuel inflow passage communicates with a certain level below the float chamber 4, and a suction valve seat 26 is formed in the starting fuel inflow passage corresponding to the suction-side check valve 25. Is pressed against the suction valve seat 26 by the spring 27.

Reference numeral 28 denotes a starting fuel discharge passage whose one end is opened at a substantially central portion of the starting fuel pump chamber 21 and whose other end is opened to the intake passage 2 on the engine side (left side in the figure) from the throttle valve 12. In the path, a discharge valve seat 29 and a discharge-side check valve 31 that closes the discharge valve seat 29 by being pressed by a spring 30 are arranged.

A valve seat 32 is formed at the opening end of the starting fuel discharge passage toward the starting fuel pump chamber 21.

Reference numeral 33 denotes an opening / closing valve unit provided integrally with the partition body 20,
The opening / closing valve portion 33 is arranged corresponding to the valve seat 32 at the end of the starting fuel discharge passage 28, and opens and closes the valve seat 32 in accordance with the movement of the partition body 20, thereby controlling the opening and closing of the starting fuel discharge passage 28. I do. Further, the operating rod 34 is integrally arranged on the partition body 20,
By moving the operating rod 34, the partition 20 and the on-off valve portion 33 move synchronously. N indicates a first state (the state shown in FIG. 1) in which the operating rod 34 (including the partition body 20 and the opening / closing valve section 33) is fully pressed toward the starting fuel pump chamber 21 and a state in which the operating rod 34 is fully pulled toward the atmosphere chamber 22. The second state (the second pulling state to the left in the figure)
(A state shown in the figure) and an intermediate position regulating member for holding it at a substantially intermediate portion. Specifically, a groove 34A is formed in the operation rod 34, and the groove 34A is operated when the operation rod 34 is operated to the intermediate position. A ball 35 and a spring 36 that apply a pressing force perpendicular to the operating rod 34 with elastic force.

Also, 37 is contracted in the atmosphere chamber 22 and one end is in the cover 23,
The other end is a spring which is locked to the partition 20 and presses the partition 20 toward the starting fuel pump chamber 21.

When the above-described intermediate position regulating member N is operated, the pressing force of the ball 35 acting on the groove 34A of the operating rod 34 by the spring 36 in the direction perpendicular to the longitudinal axis direction Y-Y of the operating rod 34 is applied. Spring in the middle position of the operating rod 34
37 is greater than the pressing force of the operating rod 34 in the longitudinal axis direction YY, whereby the operating rod 34 can be held at the intermediate position.

 Next, the operation will be described.

First, the case where the engine ambient temperature and the engine temperature are high will be described. Since the temperature is high, it is not necessary to supply a rich mixture to the engine.

The starting device is therefore kept inactive. This state is shown in FIG. 1, in which the partition 20 is pressed by the spring 37 toward the starting fuel pump chamber 21.
The opening / closing valve section 33 provided integrally with the partition body 20 is a starting fuel discharge path.
Valve seat located at the opening end of the starting fuel pump chamber 21 on the side of 28
The starting fuel is not supplied from the starting fuel discharge passage 28 into the intake passage 2 and the fuel at the engine temperature is supplied to the main nozzle 10 and the low-speed injection hole (not shown). It is supplied to the intake pipe to satisfy the start.

Next, regarding the start in a state where the engine ambient temperature is low, prior to the start operation of the engine, first, the operating rod 34 is fully pulled to the left in the drawing against the spring force of the spring 37, as shown in FIG. Explicitly. By this operation, the partition body 20 and the opening / closing valve section 33 also move to the left in synchronization with the operating rod 34, and the opening / closing valve section 33 opens the valve seat 32 and increases the volume of the starting fuel pump chamber 21. Let it.

According to this, the suction side check valve 25 opens the suction valve seat 26, and the discharge side check valve 31 closes the discharge valve seat 29.

Therefore, by this operation, the fuel stored in the float chamber 4 is sucked into the starting fuel pump chamber 21.

Next, the left pulling force on the operating rod 34 is released. According to this, the operating rod 34 is automatically (to the right) toward the starting fuel pump chamber 21 in the figure by the spring force of the spring 37. The operation rod 34 stops in a state where the groove 34A is engaged with the ball 35 as the intermediate position regulating member N. (This state is shown in FIG. 3.) When the operating rod 34 stops at the intermediate position,
This can be achieved by appropriately increasing the pressing force of the spring 36 of the ball 44 acting in the direction perpendicular to the tension in the longitudinal axis direction Y-Y of the operating rod 34 of 37.

According to the movement of the operating rod 34 to the intermediate position, the starting fuel pump chamber 21 is compressed and the chamber volume is reduced, so that the discharge side check valve 31 opens the discharge valve seat 29 and the starting fuel discharge passage 28
The starting fuel is injected and supplied into the intake passage 2 to prepare for the first and complete explosion of the engine.
A cranking operation for starting the engine is started after a step of fully pulling to the left of 34 and a return step of releasing the pulling force on the operating rod for returning to the intermediate position. Then, since the fuel in the starting fuel pump chamber 21 has already been injected and supplied from the starting fuel discharge passage 28 into the intake pipe, a sufficiently rich air-fuel mixture can be supplied to the engine, and the first explosion and complete explosion of the engine can be reliably performed. Obtainable.

Then, when the engine enters a warm-up operation state after a complete explosion, the operating rod 34 is held at the intermediate position and the valve seat 32 is held open by the on-off valve portion 33. The negative thickness acts on the discharge check valve 29 from the start fuel discharge passage 28, opens the discharge side check valve 31 from the discharge valve seat 29 against the spring force of the spring 30, and the fuel in the start fuel pump chamber 21 The starting fuel discharge path
This is supplied to the intake passage 2 from 28 to satisfy the warm-up operation.

Although the warm-up operation time varies depending on the performance of the engine and the ambient temperature, the starting fuel pump chamber is located at the intermediate position by the intermediate position regulating member N of the operating rod 34 and the opening / closing valve portion 33 holds the valve seat 32 open. Since a suction negative pressure acts on the inside of the fuel injection passage 21 from the starting fuel discharge passage 28, the suction-side check valve 25 opens the suction valve seat 26 and can supply the fuel in the float chamber 4 sequentially, causing no problem. Never.

Next, when the warm-up operation of the engine is completed, the operating rod 34 is returned from the intermediate opening state in FIG. 3 to the original position in FIG. According to this, since the on-off valve portion 33 closes the valve seat 32, fuel does not flow out of the starting fuel pump chamber 21 to the starting fuel discharge passage 28.

Also, during operation of the engine, a negative pressure in the intake passage 2 acts on the starting fuel discharge passage 28, and the discharge-side check valve 31 is
It is predicted that the opening will be opened from the discharge valve seat 29 against the spring force of 30. Even if the starting fuel discharge passage 28 is opened, this negative pressure will immediately act on the lower part of the on-off valve portion 33. , On-off valve part 33
On the other hand, the opening / closing valve portion 33 is pressed by the spring 37 toward the closing side of the valve seat 32, so that the starting fuel discharge path 28 is completely closed and held, and unnecessary fuel is sucked. It is not sucked into the road 2 and does not hinder normal operation of the engine.

〔The invention's effect〕

As described above, according to the vaporizer starting device according to the present invention,
It has the following effects.

Especially at the time of starting at low engine ambient temperature,
At the time of a complete explosion, the desired starting fuel suitable for a complete explosion was directly injected into the intake passage from the starting fuel discharge passage without relying on the intake passage negative pressure for the fuel in the starting fuel pump chamber. You can get a start.

During the warm-up operation of the engine, the start-up fuel is automatically discharged from the start-up fuel discharge passage to the intake passage due to the negative pressure generated in the intake pipe, so that the warm-up operability can be improved.

When the engine is started, the operating rod is pulled toward the atmosphere chamber and then released, and the operating rod is automatically placed in the middle position to supply the starting fuel necessary for the first and complete explosion of the engine. On the other hand, the warm-up operation of the engine can be prepared for the warm-up operation while maintaining the intermediate position of the operation rod, and at the end of the warm-up operation, the operation rod is pressed toward the starting fuel pump chamber to return to the original position. It is only necessary to return it, and the operation at the time of the start becomes extremely simple, and no skill is required for the start, and it is particularly suitable as a starter of an outboard motor or a general-purpose engine.

Since the injection amount of the starting fuel at the time of starting is always determined to be constant by the spring force of the spring that presses the operating rod toward the starting fuel pump chamber, the pressing speed at which the operating rod presses the starting fuel pump chamber may change. In addition, the engine is always supplied with a fixed starting fuel set without regard to the operator's intention, so that the starting performance can be surely and well performed.

Furthermore, during the operation of the engine, the negative pressure generated in the intake passage was completely shut off by the on-off valve portion and the valve seat of the compartment, so that any negative pressure was applied to the compartment outside the on-off valve portion. It does not work, but it can improve the durability of the partition when the partition is formed of an elastic rubber material such as a diaphragm, and can provide a stable vaporizer starting device for a long time. It is.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a closed state of a starting fuel discharge passage of a starting device for a carburetor according to the present invention, and FIG. 2 is a view showing a state in which an operating rod in FIG. FIG. 3 is a longitudinal sectional view of a main part showing a state where the operating rod is returned to the intermediate position from the state of FIG. 1 ... vaporizer main body, 4 ... float room, 20 ... compartment, 21 ...
... Start fuel pump chamber, 22 ... Atmosphere chamber, 24 ... Start fuel inflow passage, 25 ... Suction side check valve, 28 ... Start fuel discharge passage, 31
…… Discharge-side check valve, 32 …… Seat, 33 …… On-off valve part, 34…
… Operating rod, 37… spring, N… intermediate opening regulating member

Claims (2)

(57) [Claims] 1. A float for disposing a float chamber body 3 on a side of a carburetor body 1 through which an intake passage 2 penetrates, and for storing a constant liquid level inside the float chamber body 1 and the float chamber body 3. In the carburetor in which the chamber 4 is formed; the interior is divided into a starting fuel pump chamber 21 and an atmosphere chamber 22 by a partition body 20, and the starting fuel pump chamber 21 has a suction-side check valve therein.
A starting fuel inflow passage 24 communicating below a certain level of the float chamber 4 and a starting fuel discharge passage 28 in which a discharge-side check valve 31 is disposed are opened. The partition 20 pressed toward the starting fuel pump chamber 21 integrally includes an opening / closing valve portion 33 that can control opening and closing of the starting fuel discharge path and an operating rod 34 that can apply a pump operating force to the partition 20. The operating rod includes a first state in which the starting fuel discharge passage 28 is closed by the on-off valve portion 33 of the partition 20 and a second state in which the partition 20 is pulled to the atmosphere chamber 22 side. An intermediate position regulating member N which can be held at the intermediate position is provided, and when the attractive force on the operating rod 34 is released from the second state, the partition 20 is automatically returned to the substantially intermediate position by the spring force of the spring 37, and the starting fuel pump chamber
A starting device for a carburetor that discharges the fuel in 21 through a starting fuel discharge passage 28. 2. A groove 34A in which the intermediate opening regulating member N is provided in a part of the operation rod 34, and a longitudinal axis direction Y- of the operation rod 34 of the spring 36 which is elastically pressed by the groove. 2. A carburetor starting device according to claim 1, wherein said starting member is formed by a ball 35 which overcomes the pressing force applied to Y and holds said operating rod at a fixed position.