JPH037569Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an LPG fuel system mounted on an industrial vehicle, such as a forklift, and specifically relates to a starting assist device for assisting engine starting in a low-temperature environment.

Prior Art A conventional LPG fuel system will be explained based on the LPG fuel system diagram shown in FIG. 1 and the vertical sectional view of the regulator shown in FIG. Liquid LPG taken out from cylinder 1 passes through filter 2 in the engine room,
Here, impurities are filtered, and the water enters the regulator 4 via the solenoid valve 3. The pressure was reduced by regulator 4.
Here, the LPG is vaporized into a gaseous state, and is sucked into the engine 6 via the carburetor 5.

That is, when the engine switch 7 is turned on and the LPG switch 8 is turned on, the liquid LPG introduced into the chamber 10 from the fuel inlet 9 of the regulator 4 is heated to the first valve attached to the first valve lever 11 by its own vapor pressure. The illustrated face valve 12 (hereinafter simply referred to as the first valve) is pushed open against the first diaphragm hook 13 and enters the primary decompression chamber 14 and slow passage 15 where it is depressurized and vaporized. When the pressure inside the primary decompression chamber 14 reaches 0.25 to 0.35 Kg/cm ² , the first diaphragm 16 pushes the first regulator spring 17 and the first diaphragm hook 13 operates the first valve lever 11 .
The valve 12 is closed, and in this way the pressure within the primary decompression chamber 14 is maintained constant.

In this state, when the engine switch 7 is turned to start, the cranking vacuum acts on the slow lock diaphragm 20 via the vacuum pipe 19 communicating with the intake manifold 18, and by releasing the slow lock diaphragm 20, the nozzle is opened. 21, the LPG in the primary decompression chamber 14 is supplied from the slow chamber 22 to the carburetor 5 via the slow pipe 23, and the first explosion is performed. Next, when the throttle valve of the carburetor 5 is slightly opened, the vacuum pressure of the carburetor 5 acts on the secondary pressure reducing chamber 25 of the regulator 4 through the main pipe 24, so that the second diaphragm 26, which receives atmospheric pressure on the back side, moves toward the secondary decompression chamber 25 and opens the second illustration face valve 28 (hereinafter simply referred to as the second valve) via the second valve lever 27 against the force of the spring 29. Therefore, the LPG in the primary decompression chamber 14 flows into the secondary decompression chamber 25 through the communication hole 30, and is further supplied from there to the carburetor 5 via the main pipe 24, thereby causing complete explosion.

However, when a forklift equipped with the above-mentioned LPG fuel system is used in a low-temperature environment, such as in a cold region or in a freezer, LPG becomes tar-like (jelly-like) and enters the slow chamber 22, especially in slow systems with narrow passages. It may accumulate and block the slow passage. Therefore, conventionally, the engine cooling water is circulated through the regulator 4 through the water pipe 31 to loosen the regulator 4. However, this method is not effective when starting the engine. There was a problem where the camera sometimes did not load.

Purpose of the invention The purpose of the present invention is to provide a starting assist device for an LPG fuel system for an industrial vehicle that can eliminate the above-mentioned conventional problems.

Structure of the Invention In the present invention, the primary decompression chamber of the regulator is connected to the carburetor through a slow pipe, the secondary decompression chamber of the regulator is connected to the carburetor through a main pipe, and the secondary decompression chamber includes a primary decompression chamber and a secondary decompression chamber. In an LPG fuel system equipped with an illustrative face valve for opening and closing a communication hole connecting to a decompression chamber, the slow pipe is equipped with a pressure sensor for detecting the pressure inside the pipe, and the regulator is equipped with a pressure sensor for detecting the pressure inside the pipe. An actuator for opening and closing the illustrated face valve is installed, and the actuator is operated based on a command from the pressure sensor only when the pressure in the slow pipe is below a set value when the engine is started. It is configured to forcibly open the station face valve, and therefore, when starting the engine in a low temperature environment, the slow system passage is
If the LPG gas turns into tar and its flow is obstructed, a pressure sensor installed in the slow pipe detects this and the actuator forces the illustration face valve to open. This makes it possible to start the engine by supplying the LPG gas in the primary decompression chamber from the secondary decompression chamber to the carburetor via the main pipe.

Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 3 to 5. However, the same parts as the conventional ones are given the same reference numerals and the explanation thereof will be omitted. As shown in FIG. 3, a slow pipe 2 serves as a slow system passage connecting the regulator 4 and the carburetor 5.
3 is provided with a pressure switch 32 as a pressure sensor, and the pressure switch 32 is turned on when the slow system LPG pressure is, for example, 0.25 kg/cm ² or less, and turned off when it is above. It is set. On the other hand, as shown in FIG. 4, an electromagnet 33 is attached to the regulator 4 as an actuator for operating a second diaphragm 26 for the secondary decompression chamber 25, and an actuator 34 of the electromagnet 33 penetrates the atmospheric pressure chamber 35. The second diaphragm 26 is brought into contact with the center of the back surface thereof. That is, when the electromagnet 33 is activated, it pushes the second diaphragm 26 to open the second valve 28.

As shown in FIG. 5, the engine switch 7 and the relay R are connected in series to the battery B, and the normally open contact R _a of the relay R, the pressure switch 32 and the solenoid SOL of the electromagnet 33 are connected in series.
is connected to battery B in series.

This embodiment is configured as described above,
The effect will be explained below. Now, to start the engine, turn on engine switch 7 and LPG switch 8.
When each is turned ON, the normally open contact R _a is turned ON by the excitation of the relay R, and the solenoid SOL of the electromagnet 33 is energized. At this time, if LPG is deposited in the throat chamber 22 in the form of tar and is blocked, it flows into the primary decompression chamber 14 and the slow passage 15 of the regulator 4, and
The vaporized gaseous LPG is transferred to a nozzle 21 by a cranking vacuum acting on a slow lock diaphragm 20 through a vacuum pipe 19.
Even if it is opened, it cannot flow into the throat chamber 22, so the pressure inside the throat chamber 22 does not increase, and the pressure switch 32 remains in the ON state.

Therefore, the solenoid SOL of the electromagnet 33 remains energized, and the actuator 3 of the electromagnet 33 remains energized.
5 pushes the second diaphragm 26 and opens the second valve 28 via the second valve lever 27 against the spring 29. Therefore, the LPG in the primary decompression chamber 14 flows into the secondary decompression chamber 25 through the communication hole 30, and from there the LPG enters the main pipe 24.
It is supplied to the carburetor 5 through. That is,
When starting the engine, if the slow system passage is blocked by LPG that has turned into tar, the main pipe 24 can be used to supply fuel and start the engine.

However, while the main system was being used to operate the engine slowly, the water pipe 3
As the temperature of the cooling water circulating in the primary decompression chamber 14 increases, the regulator 4 is heated, and the tar-like LPG in the throat chamber 22 is melted and the slow system is opened. It is then supplied to the carburetor 5. Therefore, the pressure in the slow system increases and the pressure switch 32 is turned off, so that the solenoid SOL of the electromagnet 33 is deenergized and the normal state is restored.

Note that when the slow system passage is not blocked, engine starting is performed in the same manner as before, and in that case, the electromagnet 33 temporarily performs the above operation, but immediately returns to its original state. It is.

Effects of the invention As detailed above, this invention is for industrial vehicles.
In an LPG fuel system, if the LPG in the slow system passage of the regulator changes into a tar-like state due to the low temperature environment and its flow is obstructed, this will be automatically detected and the main system passage will be used. Since fuel can be supplied to the carburetor by the engine, the engine can be started reliably, making it an extremely useful device as a starting aid.

[Brief explanation of the drawing]

Fig. 1 is a conventional LPG fuel system diagram, Fig. 2 is a vertical cross-sectional view showing a conventional regulator, Fig. 3 is an LPG fuel system diagram showing an embodiment of the present invention, and Fig. 4 is a vertical cross-sectional view showing the regulator. FIG. 5 is an electric circuit diagram for controlling the electromagnet. 1... cylinder, 4... regulator, 5... carburetor, 6... engine, 12... first illustrated face valve, 14... primary decompression chamber, 16... first diaphragm, 20...
Slow lock diaphragm, 22... Slow chamber, 23... Slow pipe, 24... Main pipe, 25... Secondary decompression chamber, 26... Second diaphragm, 28... Second illustration face valve, 30... Communication Hole, 32...pressure switch, 33...electromagnet, R...relay.

Claims (1)

[Scope of utility model registration request] The primary decompression chamber of the regulator is connected to the carburetor by a slow pipe, the secondary decompression chamber of the regulator is connected to the carburetor by a main pipe, and the secondary decompression chamber has a communication link between the primary decompression chamber and the secondary decompression chamber. LPG with illustrated face valve to open and close the hole
In the fuel system, the slow pipe is provided with a pressure sensor for detecting the pressure inside the pipe, and the regulator is provided with an actuator for opening and closing the illustrated face valve, so that the slow pipe is equipped with an actuator for opening and closing the illustrated face valve. An industrial vehicle characterized in that the illustrated face valve is forcibly opened by operating an actuator based on a command from the pressure sensor only when the pressure in the pipe is below a set value. Starting aid device for LPG fuel equipment.