JPH0579821B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for attaching the vaporizer to the air intake port of the vaporizer in an existing internal combustion engine, for example, a gasoline engine. This invention relates to a dual-use adapter device that can be used for both liquefied gas fuel and other fuels.

(Prior Art) Conventional adapters of this type include, for example, Japanese Patent Application Laid-open No. 57-140553 and Japanese Patent Application Laid-open No. 59-188059. In these devices, a switching valve is provided in the adapter, and the switching valve is opened and closed using the engine's manifold negative pressure. That is, when gasoline is used as fuel, the diaphragm is operated by the manifold negative pressure to open the switching valve, and air is mixed in a ratio suitable for gasoline fuel.On the other hand, when LP gas is used as fuel, The ventilator was returned to the closed state by the action of a return spring without introducing negative pressure, creating a ventilary negative pressure suitable for drawing out LP gas, and mixing air in a ratio suitable for LP gas fuel. .

(Problem to be Solved by the Invention) However, the operating condition of the engine constantly changes. For example, during sudden acceleration with gasoline fuel, the throttle valve is fully open, so as the manifold negative pressure decreases, the switching valve is closed. This caused the problem that the engine was in a state as if the chiyork valve had been closed, resulting in an increase in exhaust gas (COHC) due to excess fuel, resulting in a decrease in output.

In addition, when switching from gasoline fuel to LP gas fuel, the manifold negative pressure is no longer applied, so the switching valve also becomes closed in conjunction with this,
There was also the problem that the remaining gasoline in the float chamber could not be completely consumed under normal conditions.

In view of the above-mentioned problems of the prior art, the present invention provides a vacuum cleaner that maintains the switching valve in an open state when the manifold negative pressure drops or stops applying when an actuator such as a diaphragm is operated. To provide a dual-use adapter device that can maintain pressure for a predetermined period of time and can switch between liquefied gas fuel and other fuels.

(Means for solving the problem) Therefore, the dual-use adapter device according to the present invention has the following features:
It consists of the following composition. That is, it has an adapter body that is attached to an air intake port of a carburetor in a gasoline engine or other internal combustion engine. The main body is provided with a fuel supply port for supplying liquefied gas fuel such as LP gas, and an injection port that communicates with the supply port and opens into an inlet passage within the main body. The intake passage is configured to allow an amount of air suitable for the existing fuel of the internal combustion engine to pass through the intake passage in an open state, and to generate a ventilary negative pressure suitable for drawing out the liquefied gas fuel from the injection port in the closed state. , a switching valve is provided to allow an amount of air suitable for the liquefied gas fuel to pass therethrough. Further, an actuator is attached to the adapter body to open the switching valve using the manifold negative pressure of the internal combustion engine. Moreover, in the negative pressure circuit that operates this actuator, when the manifold negative pressure decreases when the actuator is operated,
A negative pressure correction circuit is provided for maintaining negative pressure for a predetermined period of time to keep the switching valve open.

(Example) Hereinafter, this invention will be described as a gasoline engine vehicle and
An embodiment of a dual-use adapter device for LP gas engine vehicles will be described based on the drawings.

In the figure, reference numeral 1 indicates an adapter body interposed between a carburetor of an internal combustion engine such as a gasoline engine and an air cleaner for cleaning air taken into the carburetor. The main body 1 has a cylindrical shape as a whole, and has a small diameter cylindrical part 2 attached to the air intake port of the carburetor at its lower part. A connecting pipe 3 connecting to a liquefied gas fuel source such as LP gas supplied via a vapor riser (not shown) is attached to one side of the upper part of the main body 1, and a fuel supply port 4 leading into the main body 1 is installed. establish.

The main body 1 is further provided with a ventilator 5 and an injection cylinder 7 that forms an annular gas passage 6 between the outer circumference of the ventilator 5 and the concave peripheral wall surface of the main body 1. In bench yuri 5,
A plurality of injection ports 9 communicate with the supply port 4 via the gas passage 6 and open to the suction path 8 in the main body.
will be established. In order to inject the gas fuel equally from each injection port 9, injection resistance is reduced as the distance from the supply port 4 increases to form an ideal air-fuel mixture. That is, in this embodiment, as clearly indicated by the broken line in FIG.
For this, the diameter, that is, the opening area is made small,
It increases as the distance from the supply port 4 increases, and the injection resistance is gradually reduced.

The suction passage 8 is located slightly below the injection cylinder 7.
A switching valve 10 is disposed inside the engine to change the amount of air passing through the intake passage 8 depending on the fuel used. That is, the switching valve 10 is provided with a throttle hole 11 in the center thereof, and in the open state, it takes a position parallel to the flow of intake air, and allows an amount of air suitable for existing fuel such as gasoline fuel to pass through. Further, in the closed state, the ventilator takes a position perpendicular to the flow of intake air, and generates a negative pressure of the ventilate suitable for drawing out the liquefied gas fuel from the injection port 9, and allows an amount of air suitable for the liquefied gas fuel to pass through.

The switching valve 10 is opened and closed by remotely controlling the actuator that operates the switching valve 10 by switching the switching switch S, as shown in the piping and wiring diagram of FIG.

That is, the main body 1 is provided with an actuator that opens the switching valve 10 by utilizing the manifold negative pressure of the existing internal combustion engine. As an actuator, for example, a diaphragm 12 is used, and the switching valve 10 is rotated by its suction action through a link 13 and a valve shaft 14, so that it assumes a position parallel to the flow of intake air. Furthermore, when the suction action ceases, the switching valve 10 is
is returned to its original position, that is, a position perpendicular to the flow of intake air.

As a means for applying manifold negative pressure to this diaphragm 12 and for blocking the negative pressure and introducing atmospheric air into the diaphragm 12 side,
A solenoid valve 16 is provided. A tube 17 connected to the manifold is connected to the inside of the electromagnetic valve 16, and a tube 18 connected to the diaphragm 12 is connected to the outside. The electromagnetic valve 16 also has an outside air intake port T connected to the outside air.
will be provided.

On the other hand, the changeover switch S has a switching position A for turning off the power, a switching position B for driving the electromagnetic valve 19 that drives the electromagnetic valve 16 and controls supply and cutoff of existing fuel to the carburetor, and , liquefied gas fuel adapter body 1
It is provided with a switching position C for driving the electromagnetic valve 20 that controls supply and cutoff to the electromagnetic valve 20. Therefore, by switching the changeover switch S to A, B, or C, the fuel supply can be cut off or selected.
Furthermore, opening and closing of the switching valve 10 can be remotely controlled.

A negative pressure circuit that operates the diaphragm 12 is provided with a predetermined negative pressure to maintain the switching valve 10 in an open state when the manifold negative pressure decreases when the diaphragm 12 as an actuator is activated. A negative pressure correction circuit is provided to maintain the negative pressure for a certain amount of time.

That is, the correction circuit is composed of a control valve 21 for adjusting negative pressure and a tank 22 for accumulating negative pressure, which are connected to the outside of the electromagnetic valve 16.

First, the control valve 21
The electromagnetic valve 16 is connected to the outside of the electromagnetic valve 16 via the electromagnetic valve 8 . This control valve 21 is equipped with a check valve 23 and a ventilation section 24 inside, so that ventilation is smooth from the diaphragm 12 side to the electromagnetic valve 16 side, but resistance is generated to ventilation in the opposite direction. ing. Therefore,
Even if the negative pressure temporarily decreases, or even if the negative pressure begins to decrease due to the introduction of atmospheric air after the negative pressure is shut off, the change is not directly applied to the diaphragm 12 side.

Further, the tank 22 has tubes 25 and 26.
The control valve 21 and the diaphragm 12 are connected to each other via the control valve 21 and the diaphragm 12 . This tank 22 is a hollow container made of steel, for example, and is capable of accumulating a predetermined amount of the negative pressure. Therefore, while the manifold negative pressure decreases and the change is delayed from being transmitted to the diaphragm 12 side by the control valve 21, the accumulated negative pressure acts on the diaphragm 12, and the switching valve 10 can be kept open for a while.

The time period during which negative pressure can be maintained by this correction circuit is determined by the interrelationship between the pressure accumulation capacity of the tank 22 and the air permeability of the ventilation section 24 of the control valve 21, and is preferably 60 seconds. Set it so that it can be maintained for a long time.

Further, 27 is a main power switch for driving each electromagnetic valve 16, 19, 20.

Now, the operation of the dual-use adapter device configured as above will be explained.

First, when using existing fuel such as gasoline, changeover switch S is switched from A to B.
By this switching, the electromagnetic valve 16 is driven, and the tubes 17 and 18 are communicated with each other, and the outside air intake port T communicating with the outside air is closed, thereby applying a manifold negative pressure to the diaphragm 12. The diaphragm 12 is actuated by this negative pressure, and the switching valve 10 is rotated via the link 13 and the valve shaft 14 so that it is in the open state, that is, in a position parallel to the flow of intake air. This allows an amount of air suitable for the existing fuel to pass through the adapter body 1. On the other hand, when the solenoid valve 16 is driven, the solenoid valve 19 is also driven to supply the existing fuel to the carburetor.

In this way, while the engine is running on existing fuel,
For example, when driving rapidly by pressing the accelerator all the way down, such as when climbing a hill, the throttle valve opens fully and the manifold negative pressure drops. However, due to the negative pressure correction circuit described above, the switching valve 10
Since the negative pressure for keeping the switch open is maintained for a predetermined period of time, the switching valve 10 is not closed but remains open for a while. Normally, it is impossible to fully press the accelerator for more than 60 seconds, so
If you set the correction time to about 60 seconds, no problem will occur. That is, when the depression is released, the manifold negative pressure is restored again, and therefore the switching valve 10
will remain open as before,
The engine can continue to operate in a healthy manner.

Next, to switch the fuel used to liquefied gas fuel such as LP gas, first turn the changeover switch S to A.
Return to That is, by switching to A, both electromagnetic valves 19 and 20 cut off the fuel supply.
At the same time, the tube 17 is closed by the electromagnetic valve 16, so that the manifold negative pressure is cut off, and at the same time, the outside air intake port T is opened, so that atmospheric air is introduced into the diaphragm 12 side.
The negative pressure begins to decrease. However, as described above, since the negative pressure correction circuit operates, the atmosphere is introduced only gradually, and therefore, the switching valve 10 does not close suddenly but remains open for a while. During this time, the existing fuel remaining in the float chamber is completely consumed under normal conditions.

Then, the changeover switch S is switched from A to C at the right time. By switching to C, the electromagnetic valve 20 is driven and liquefied gas fuel is supplied to the adapter main body 1. On the other hand, after a predetermined period of time has elapsed, the correction circuit ceases to work, and the switching valve 10 is rotated back to the closed state, that is, the position perpendicular to the flow of intake air, by the action of the return spring 15. As a result, the air passing through the adapter main body 1 is throttled, and a ventilary negative pressure suitable for drawing out the liquefied gas fuel from the injection port 9 is generated, and an amount of air suitable for the liquefied gas fuel passes through. A mixed gas with an optimum air-fuel ratio is formed.

Note that in the above embodiments, an example in which gasoline is used as the existing fuel has been described, but the present invention is not limited to gasoline, and other fuels such as light oil may also be used.
Similarly, the liquefied gas fuel is not limited to LP gas, and may be, for example, liquefied natural gas or other liquefied gas fuel.

(Effects of the Invention) As is clear from the detailed description above, since the dual-use adapter device according to the present invention is equipped with a negative pressure correction circuit, even if the manifold negative pressure decreases when the actuator is operated, Negative pressure for keeping the switching valve open can be maintained for a predetermined period of time. Therefore, even if the manifold negative pressure temporarily decreases due to sudden acceleration while the internal combustion engine is operating with existing fuel, the switching valve provided in the adapter body must be kept open. This allows the engine to continue operating in a healthy condition.

In addition, when switching from existing fuel to liquefied gas fuel, even if negative pressure is no longer applied due to the switching operation, the switching valve can be kept open for a while by the function of the correction circuit as described above. This allows the existing fuel remaining in the float chamber to be completely consumed under normal conditions.

Furthermore, as shown in the embodiment, if a plurality of injection ports are provided in the adapter main body and the injection resistance of the plurality of injection ports decreases as the distance from the fuel supply port increases, the intake air and liquefaction The mixture with the gas fuel can be evenly distributed and the combustion effect can be enhanced.

[Brief explanation of the drawing]

The drawings show an embodiment of the dual-use adapter device according to the present invention, in which FIG. 1 is a front view of the adapter main body, FIG. 2 is a plan view of the same main body, and FIGS. A-A sectional view and B in the figure
-B sectional view and FIG. 5 show the piping and wiring diagram of the entire adapter device. 1...Adapter body, 4...Fuel supply port, 8
...Suction passage, 9...Injection port, 10...Switching valve.

Claims (1)

[Claims] 1. It has an adapter body that is attached to the air intake port of a carburetor in a gasoline engine or other internal combustion engine, and the adapter body has a fuel supply port that supplies liquefied gas fuel such as LP gas, and a fuel supply port that supplies liquefied gas fuel such as LP gas. an injection port that communicates with the supply port and opens into an inlet passage in the main body, and allows an amount of air suitable for the existing fuel of the internal combustion engine to pass through the intake passage in an open state;
The adapter body is further provided with a switching valve that generates a ventilary negative pressure suitable for drawing out the liquefied gas fuel from the injection port in the closed state and that allows an amount of air suitable for the liquefied gas fuel to pass through. , an adapter device including an actuator that operates the switching valve to an open state using manifold negative pressure of the internal combustion engine, wherein a negative pressure circuit that operates the actuator includes a negative pressure circuit that operates the switching valve when the actuator is operated. Both liquefied gas fuel and other fuels, characterized in that a negative pressure correction circuit is provided to maintain negative pressure for a predetermined period of time to keep the switching valve open when the manifold negative pressure decreases. A dual-use adapter device that can be used by switching. 2. The correction circuit is provided on the outside side of the electromagnetic valve that applies manifold negative pressure to the actuator, and also cuts off the negative pressure and introduces atmospheric air to the actuator side, and Although ventilation to the electromagnetic valve side is smooth, there is resistance to ventilation in the opposite direction, and a control valve that adjusts the negative pressure so that the change due to the decrease in negative pressure does not act directly on the actuator side, and the same control valve. The liquefied gas fuel according to claim 1, characterized by comprising a negative pressure accumulation tank connected between the valve and the actuator and capable of accumulating negative pressure. A dual-use adapter device that allows you to switch between using other fuels. 3. The injection port comprises a plurality of injection ports whose injection resistance decreases as the distance from the fuel supply port increases. A dual-use adapter device that can be used by switching. 4. The injection resistance is reduced by increasing the opening area of the plurality of injection ports as the distance from the fuel supply port increases.
A dual-use adapter device that can switch between the liquefied gas fuel and other fuels according to claim 3.