JPS63198763A - Lpg fuel feeding device for internal combustion engine - Google Patents

Abstract

PURPOSE:To correctly cut off a fuel feeding passage when an engine is stopped by interlocking a fuel control valve with an OR circuit connected to an engine operation state detector in the fuel control valve provided on the fuel feeding passage between an LPG bottle and a mixer. CONSTITUTION:A vaporizer 2 constituted of a primary chamber 21 and a secondary chamber 22 is provided on the fuel feeding passage 5 of a main system between an LPG bottle 3 and a mixer 1. The secondary chamber 22 of the vaporizer 2 is connected to the suction passage downstream a throttle valve 14 via the fuel feeding passage 51 of a slow system,and fuel control valves 4, 41 are provided on the fuel feeding passages 5, 51. In this case, a boost switch 9 is provided on an intake manifold 11, and the engine operation state is judged by an OR circuit 10 based on the output signal of this switch 9 and the starter signal of an ignition key 12. When the OR circuit 10 judges the stop of an engine E, it closes the fuel control valves 4, 41 and instantly stops the feed of the LPG fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel supply device for an internal combustion engine that uses LPG as fuel.

[Conventional technology]

In a conventional device of this type, the primary chamber 2 is
．． And secondary room 2! Vaporizer 2 consisting of LPG
The cylinder 3 is connected to the mixer 1 connected to the engine side, and the secondary chamber 2t of the vapor riser 2 is connected to the main system supply passage 5 via the fuel control valve 4, and the firebox 2.
A slow cut solenoid valve 7 and a throttle valve slow adjust screw 7 are connected through a slow system supply passage 51. The vaporizer 2 is LPG
The high-pressure liquid fuel sent from 3 to the vapor riser 2 is depressurized and turned into vaporized gaseous fuel, and the pressure is regulated to optimize the output and fuel consumption of the engine. 21, the high pressure gas is depressurized, and furthermore, in the secondary chamber 2t, atmospheric pressure (approximately 0.2 to 0
．． Reduce the pressure to around 3 kg/+yr) and mixer 1.
We are controlling the supply to. The LPG cylinder 3 is connected to the first combustion chamber 2° of the vapor riser 2 via an LPG solenoid valve 6, and the LPG cylinder
Solenoid valve 6 and slow cut solenoid valve 7
Open each valve to connect the main system supply passage 5 and the slow system supply passage 5 of the mixer l. Fuel is supplied to each.

There is a vapor riser 2 used when this mixer l is provided with a slow system supply passage, as shown in the example in Fig. 3, but as shown in Figs. 4 and 5, the slow system supply passage 51 is not provided. The one that supplies fuel only through the main system supply passage 5, that is, the downstream of the slow cut solenoid valve 7, is the secondary chamber 2 of the vapor riser 2. Items that are connected to the above are also used.

[Problem that the invention seeks to solve]

In any case, in this conventional device, the opening/closing valve 4.7 in the fuel supply passage of the slow system and main system is structured to open and close in conjunction with the ignition system of the engine, so some reason may occur during operation (ignition ON). When the engine stops (engine stall), the passage for idle air-fuel ratio adjustment is open, so LPG cylinder 3,
Fuel is supplied to the mixer 1 by gas pressure connected to the first fire chamber 2I of the vapor riser 2 and the slow adjustment screw 71.
When the engine is restarted, it will become over-concentrated and difficult to start. Also, when the engine is stopped, the vapor riser 2
The vankyuum Rotsuta diaphragm 8 operates to close the secondary valve and remove the LPG accumulated between the secondary chamber 22 and the mixer 1 and the LPG leaking from the air-fuel ratio adjustment passage.
(line pressure 0.3 k+r/aJ) was continuously released into the atmosphere, which caused problems such as a bad odor.

The present invention appropriately eliminates these conventional drawbacks, prevents LPG fuel from flowing into the mixer when the engine is stopped, makes restarting the engine extremely reliable and easy, and does not release fuel or pollute the air. It is an object of the present invention to provide a highly safe fuel supply device that is simple in structure and inexpensive, and also allows fuel savings.

[Means for solving problems]

The present invention provides: - A vapor riser consisting of a firebox and a secondary chamber is interposed in a fuel supply passage between an LPG cylinder and a mixer connected to an engine, a fuel control valve is provided in the fuel supply passage, and an engine ignition system is provided. An LPG fuel supply device for an internal combustion engine configured to open and close in conjunction with the fuel control valve, characterized in that an OR circuit connected to an operating state detection device in the engine is connected to the fuel control valve. It is.

〔Example〕

An embodiment of the present invention will be described with reference to the example shown in FIG. 1. - Firebox 2. LP vapor riser 2 consisting of
A fuel control valve 4,4. In the LPG fuel supply system configured to open and close in conjunction with the engine ignition system, the intake manifold 11 connected to the mixer 1 is equipped with a boost switch 9, and the boost switch 9 is connected to the fuel control It is connected to the OR circuit IO of a logic circuit having an OR gate connected to the ignition key 12 of the ignition system that opens and closes the valve 4, and the operating state of the engine is determined by the starter signal of the ignition key 12 and the signal from the boost switch 9. The fuel control valve 4.41 is operated based on the OR circuit 10.

In this case, the boost switch 9 provided on the intake manifold 11 is used as a device capable of detecting the operating state of the engine E, but a battery terminal of an alternator (not shown) may also be used instead.

The fuel supply passage is the secondary chamber 2 of the Baberizer 2! The main system supply passage 5 connected to the main system supply passage 5 and the slow system supply passage 51 connected to the first firebox 21 of the paper riser 2
and a fuel control valve 4 consisting of a solenoid valve provided in each passage. is turned ON and OFF by the OR circuit, but depending on the configuration of the paper riser 2, it is also possible to use only the main system supply passage to respond to engine startup.

Further, the LPG cylinder 3 has an LPG solenoid valve 6.
It is connected to the first fire chamber 2° of the paper riser 2 through the valve, and when the engine is started, the valve is opened and fuel is supplied to the fuel supply passages 5 and 51.

In the figure, 13 is a battery, I4 is a throttle valve, 15 is a main adjustment screw, and 151 is a slow adjustment screw.

Therefore, when starting the engine E, when the ignition key 12 is turned to the ST (starter) position, an ST multiplied signal is input to the OR circuit lO (in this case, the OR circuit
As shown in Table 1, the output voltage flows in the circuit 10 when either of the ST double signal boost signals is input), then the fuel control of the solenoid valves provided in the fuel supply passages 5 and 51 is performed. 21 valve 4°4 is turned off to supply fuel to mixer l.

Table 1 Thus, when the engine E is started and the starter is turned off, the ST double signal is turned OFF, but when the engine starts, negative pressure is generated in the intake manifold ll, and this causes the boost switch 9 to be activated and the OR circuit 10 to be boosted. The signal is input and the solenoid valve remains open and continues to supply fuel.

Furthermore, when the engine E is stopped, the ST double signal boost signal is OFF regardless of whether the ignition key 12 is OFF or OFF, so the OR circuit 1O closes the fuel control valve 4.41 of the solenoid valve and closes the fuel supply passage. 5
,5. The fuel control valves 4, 4, . can be operated properly.

〔Effect of the invention〕

The present invention provides an LPG fuel supply system configured to open and close in conjunction with an engine ignition system, in which an OR circuit connected to an operating state detection device in the engine is connected to the fuel control valve. Since the LPG fuel supply passage can be appropriately shut off by the control valve, the LPG fuel will not leak into the mixer, resulting in extremely good engine restartability, as well as being safe as LPG will not leak into the atmosphere. There is no discomfort or air pollution caused by the odor of LPG, there is no waste due to fuel leaks, and it has the effect of significantly saving fuel, and it is easy to configure and can be used with existing equipment, making it highly versatile and safe. It can be used as a high quality device.

[Brief explanation of the drawing]

Fig. 1 is a system explanatory diagram of an embodiment of the present invention, Fig. 2 is a system explanatory diagram of a conventional example, Fig. 3 is a vertical cross-sectional view of a paper riser used in that example, and Fig. 4 is another conventional example. Fig. 5 is a longitudinal sectional view of a paper riser used in this example. ■...Mixer, 2...Paper riser, 21.
...-Firebox, 2t...Secondary chamber, 3...LPG cylinder, 4.4. ...Fuel control valve, 5,5. ...Fuel supply passage, 6...LPG solenoid pulp, 9...Boost switch, 10...OR circuit, 11...Intake manifold 4)', 1.2...Ignition key, 13 ···Battery.

Claims (4)

[Claims] (1) L vaporizer consisting of a primary chamber and a secondary chamber
An LPG fuel supply device that is arranged in a fuel supply passage between a PG cylinder and a mixer connected to an engine, is provided with a fuel control valve in the fuel supply passage, and is configured to open and close in conjunction with an engine ignition system. An LPG fuel supply system for an internal combustion engine, characterized in that an OR circuit connected to an operating state detection device in the engine is connected to the fuel control valve. (2) The LPG fuel supply system according to claim 1, wherein the operating state detection device is a boost switch provided on an intake manifold connected to the mixer. (3) The LPG fuel supply system according to claim 1, wherein the operating state detection device is a battery terminal of an alternator. (4) The fuel supply passage is composed of a main supply passage communicating with the secondary chamber of the vapor riser and a slow system supply passage communicating with the primary chamber of the vapor riser, and the solenoid valve provided in each passage is connected to the OR circuit. ON-OFF
An LPG fuel supply device according to any one of claims 1 to 3.