JPH0443851A - Automatic priming device of engine - Google Patents

Abstract

PURPOSE:To automatically perform priming to rapidly and smoothly start an engine by closing an intake shutoff valve at the detection of the absence of fuel in an auxiliary fuel tank, and closing the intake shutoff valve at the detection of the flow-in of fuel. CONSTITUTION:When fuel runs out an auxiliary fuel tank 32 naturally becomes empty and so a liquid surface detecting switch 72 is closed. In this case the starting switch 58 of a main switch 56 is closed for starting operation and, because the liquid surface detecting switch 72 is closed, the solenoid 78 of a control relay 76 is energized to close a relay switch 80 and an actuator 74 is energized to block an intake shutoff valve 14 and a solenoid valve 68 is energized and opened. On the other hand, because the starter motor of the engine is driven via a starter relay 60, the engine is rotated and actuated as a strong vacuum pump and negative pressure is generated inside an inlet pipe 52 located beneath the shutoff valve 64 and fuel sucked into a fuel injection pump 14 from a fuel tank 16 is supplied to the auxiliary fuel tank 32.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is designed to remove air from the fuel supply system when starting the engine when the fuel runs out, the fuel filter is replaced, air leaks from the joint of the fuel supply system, etc. This invention relates to Ennon's automatic priming device that can quickly and automatically perform priming in connection with.

(Prior Art) A schematic configuration of a fuel supply device in a conventional vehicle or industrial diesel engine will be described with reference to FIG. 1 showing an embodiment of the present invention for convenience. In the drawing, reference numeral 10 denotes a fuel tank for storing fuel, and 12 denotes a fuel feed pump that sucks the fuel in the fuel tank 10 and supplies it to the large-sized fuel injection pump 14, which is a well-known priming pump that pumps manually. 16 is attached. Reference numeral 18 denotes a fuel filter interposed in the fuel supply pipe 24 between the fuel discharge port 20 of the fuel feed pump 7°12 and the fuel supply pipe 22 of the fuel injection pump f14; It communicates with the fuel tank 10 via.

(In addition, in the illustrated device, an auxiliary fuel tank 32 is interposed in the overflow pipe 30, but this tank constitutes one of the features of the present invention, as will be described later. ) 34 is a well-known fuel injection nozzle connected to the discharge port 36 of the fuel injection pump 14 via a fuel injection pipe 38;
A leak-off line 40 is connected to the fuel injection nozzle 34 of each cylinder, and communicates with the fuel tank 10 via the overflow line 30.

42 is a conceptually shown cylinder, 44 is the same cylinder 42
46 is a cylinder head, 48 is a piston fitted in the cylinder head;
50 is an intake valve housed in the cylinder head 46, 50 is an exhaust valve housed in the cylinder head 46, 52 is an intake pipe communicating with the intake valve 48 of each cylinder, and 54 is similarly connected to the exhaust valve 50 of each cylinder. 56 is a main switch with an engine starting contact 58, 60 is a starter relay, and 62 is an input terminal 6 of the main switch 56.
It is a power supply connected to %. (In addition, in the illustrated device,
An intake cutoff valve 66 is provided in the intake pipe 52 to restrict the inflow of intake air by being closed, and as will be described in detail later, the intake valve constitutes one of the features of the present invention. This is not provided in conventional engines. )
In the above-described conventional fuel supply system for a diesel engine, if fuel runs out while the engine is running, the engine will naturally stop, and the fuel supply pipe between the fuel supply 22 of the fuel injection pump 14 and the fuel tank 10 will stop. Air within the fuel tank 10 is drawn into the passage 24 and the fuel feed pump 12 .

Therefore, even if the fuel tank 10 is refilled with fuel and the start contact 58 of the main switch 56 is closed to start the engine via the starter relay 60, the fuel feed pump 1
2 idles and the fuel injection pump 14 and fuel injection nozzle 3
4 is not supplied with fuel, and the engine cannot operate independently. Therefore, the priming pump 7° 16 attached to the fuel feed pump 12 is manually operated to pump up the fuel in the fuel tank 10, and the air bleed plug 18' of the fuel filter 18 is removed to drain the air in the system to the outside. must be eliminated. 1. The same applies when the filter element of the fuel filter 18 is replaced for maintenance etc., or when air leaks from the pipe joint of the fuel supply system from the fuel tank 10 to the fuel injection pump 14. problem occurs.

(Problems to be Solved by the Invention) In the conventional fuel supply system for the diesel engine described above, in order to manually operate the priming pump when the fuel runs out, the engine room must first be opened, the priming pump must be located, and then the priming pump must be located. The pump plunger must be driven reciprocatingly with considerable force, and it takes a long time to expel air from the system and pump up fuel, which requires a large amount of work and takes a considerable amount of time to start. It was an inconvenience.

The present invention provides 1. when the fuel runs out, etc. To provide an automatic priming device for an engine that can automatically and quickly bleed air in a fuel supply system by the engine starting operation itself, which is naturally performed without requiring any special additional operation. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an intake cutoff valve that is provided in the intake pipe of an engine and restricts the inflow of intake air by closing the intake pipe, and an intake cutoff valve that is connected to the intake cutoff valve. an actuator for controlling opening and closing; an auxiliary fuel tank interposed between the overflow opening of the fuel injection pump and the fuel tank and connected to the intake pipe downstream of the intake cutoff valve via a communication pipe;
and a liquid level detecting means attached to the auxiliary fuel tank to detect the fuel liquid level in the tank, and the actuator is configured to detect when the Ennon starter switch is closed and the liquid level detecting means detects the fuel level in the auxiliary fuel tank. When the absence of fuel is detected, the intake cutoff valve is closed, and the liquid level detection means detects that fuel has flowed into the auxiliary fuel tank due to the closure of the intake cutoff valve. The present invention proposes an automatic engine liming device that operates to open the intake cutoff valve when the intake cutoff valve is opened.

(Function) According to the present invention, a small-capacity auxiliary fuel tank is interposed in the overflow pipe connecting the overflow opening of the fuel injection pump and the fuel tank, and the tank has a liquid level that detects the presence or absence of fuel. Since the meter is equipped with a liquid level detection means,
When the fuel in the fuel supply system flows out into the fuel tank and is replaced with air due to fuel shortage, etc., this fact is detected by the signal from the liquid level detection means.

On the other hand, an intake cutoff valve for restricting the inflow of intake air into the engine is provided in the intake pipe of the engine, and the intake pipe on the downstream side of the intake cutoff valve and the auxiliary fuel tank are connected by an air exhaust pipe. Further, the intake cutoff valve is energized by the liquid level detection means detecting that there is no fuel in the auxiliary fuel tank and by the starter l switch being closed to the engine main switch. It is closed by the actuator. Closing the intake shutoff valve restricts the intake air into the engine, so the rotation of the engine by the starter motor causes the engine itself to operate as a large-capacity vacuum pump, and the air is pumped into the auxiliary fuel tank and through the air exhaust pipe. Air in the fuel supply system, including the fuel injection pump as well as the fuel feed pump, is rapidly sucked out.

As a result, the fuel supply system is filled with fuel within a short period of time, for example, several seconds, due to the pressure difference between the atmospheric pressure in the fuel tank and the negative pressure in the intake pipe.

When the fuel supply system is filled with fuel, the fuel level in the auxiliary fuel tank rises and the level detection means issues a signal indicating the presence of fuel, so the actuator is deenergized and the intake cutoff valve is opened. , sufficient intake air is supplied to the engine.

Since the air in the fuel supply system is sucked out and replaced with fuel, and sufficient intake air is supplied to the engine, the Ennon can be started smoothly and can quickly achieve self-sustaining operation.

(Example) An example of the present invention will be specifically described below with reference to FIG. (Note that redundant explanations will be omitted for matters that have already been explained in connection with the previous and subsequent configurations.) According to the present invention, the overflow opening 2S of the fuel injection bong 7'14 and the fuel tank 10 are connected. A small-capacity auxiliary fuel tank 32 is installed in the overflow pipe 30, and an intake cutoff valve 64 is installed in the intake pipe 52 of the engine. The top of the auxiliary fuel tank 32 and the intake pipe 52 downstream of the intake cutoff valve 64 are connected to the air exhaust pipe 6.
6, and the air exhaust pipe 66 is connected to a solenoid valve 68.
is interposed. The overflow pulp 70 is still installed on the side wall of the relatively upper portion of the auxiliary fuel tank 32, and the overflow pipe 3 is connected to the overflow valve 70.
The downstream part of 0 is connected. Furthermore, a liquid level detection switch 72 as liquid level detection means is provided near the bottom of the auxiliary fuel tank 32, and the liquid level detection switch 72 is closed when the fuel liquid level in the tank 32 is below the set liquid level. The circuit is configured to open when the fuel level reaches a set level or higher.

The intake cutoff valve 64 is opened and closed by a second actuator, such as an electromagnetic actuator 74, and when the actuator 74 is energized, the cutoff valve 64 is closed as shown by the solid line in the figure. , when it is deenergized, it is opened as shown by the dotted line in the figure.

Further, a control relay solenoid valve 68 is formed at the starting contact 58 of the main switch 56 in parallel with the starter relay 60 so as to open when energized and close when deenergized.

One contact of the relay switch 80, which is closed by the energization of the renoids 78 and opened by the deenergization, is connected to the power supply 6.
2, and the other contact is connected to the solenoid valve 68 and the gtb solenoid of the actuator 74.

In the above configuration, during normal operation of the engine, the fuel in the fuel tank 10 is pumped up by the fuel feed pump 12 and passed through the fuel filter 18 to the fuel injection pump 14.
is supplied to The fuel pressurized and calibrated by the fuel injection pump 14 is fed under pressure from the fuel injection pipe 38 to the injection nozzle 34 of each cylinder, and is injected into the cylinder 42 . A portion of the fuel that has not been discharged from the fuel injection bong 7'14 flows from the overflow opening 2% to the overflow pipe 3o, and is transferred to the auxiliary fuel tank 32 along with the return fuel that has flowed out from the injection nozzle 34 of each cylinder to the leak-off pipe 40. flow inside. The fuel flowing into the auxiliary fuel tank 32 has a constant set pressure, for example, 1.9 kl? Overflow pipe 3 with overflow pulp 7o that automatically opens at the pressure of /crn2
0 and recirculates to the fuel tank 1o. During normal operation of the engine, the start contact 58 of the main switch 56 is, of course, open, so that the control relay 76 is deenergized, and both the actuator 74 and the solenoid valve 68 are deenergized. Therefore, since the intake shutoff valve 64 is open, the inflow of intake air into the engine is not restricted, and because the solenoid valve 68 is closed, the intake air in the intake pipe 52 is not restricted to the auxiliary fuel tank 32.
There will be no inflow into the country. On the other hand, since the auxiliary fuel tank 32 normally contains fuel up to the level of the overflow pulp 70, the liquid level detection switch 72 is open.

In addition, as long as the fuel filter 18 is not replaced due to lack of fuel or air leakage in the fuel supply system, the fuel level detection switch 72 will remain in the auxiliary fuel tank 32. Always open. Therefore, when the engine is stopped and then started, even if the starting contact 58 of the main switch 56 is closed, that is, the starter switch is closed, the solenoid 78 of the control relay 76 is not energized, and the relay Since the switch 80 is open, the intake cutoff valve 64 is not closed, and the solenoid valve 68 is closed, so that the engine starts smoothly like a normal engine.

Next, when the fuel runs out, the fuel in the fuel supply system flows out into the fuel tank 10, and the auxiliary fuel tank 32 naturally becomes empty, so the liquid level detection switch 72 is closed. At this time, when the starting contact 58 of the normal engine switch 56 is closed and a starting operation is performed, since the liquid level detection switch 72 is closed, the solenoid 78 of the control relay 76 is energized and the relay switch 80 is closed. be done. Closing the relay switch 80 energizes the actuator 74 to close the intake cutoff valve 64 and energizes the solenoid valve 68 to open it. On the other hand, since the starter motor of the engine is driven via the starter relay 60, the engine starts to rotate.

As the engine rotates, the intake shutoff valve 64 is closed and the inflow of intake air is restricted, so the ennon operates as a powerful vacuum pump and strong negative pressure is generated in the intake pipe 52 downstream of the shutoff valve 64. do. For this purpose, the air in the fuel injection pump 14, the fuel feed pump 12 and the fuel supply line 24 is sucked out for a short period of time, for example just a few seconds, via the air discharge pipe 66 and the auxiliary fuel tank 32, and the air in the fuel injection pump 1
4 is supplied with fuel sucked up from the fuel tank 10. Since fuel is supplied to the fuel injection pump 14, fuel pressurized by the pump is injected from the injection nozzle 34 into the cylinder 42 of the engine, allowing the engine to operate smoothly on its own and flowing into the cylinder 32. , same tank 32
When the fuel level within reaches the set level, the level detection switch 72 opens and the solenoid 78 of the control relay 76 is deenergized. When the solenoid 78 is deenergized, the relay switch 80 opens, so the intake shutoff valve 64 opens and the intake air necessary for the engine to operate independently is supplied. At the same time, the solenoid valve 68 closes, and the engine operates normally as described above. Returns to operating state.

According to the above configuration, when running out of fuel or replacing the fuel filter, it was necessary to manually operate the no-liming pump 16 of the fuel feed pump f12 for a long time with great force to replace the air in the fuel supply system with fuel. Compared to the configuration of
This is extremely convenient since the engine can be started smoothly. It is obvious that an air cylinder or the like can be used instead of the electromagnetic actuator in the above embodiment, and it is also obvious that a pneumatically responsive valve or the like can be used instead of the electromagnetic valve 64.

(Effects of the Invention) As mentioned above, the automatic priming device for an engine according to the present invention includes an intake cutoff valve that is provided in the intake pipe of the engine and restricts the inflow of intake air by closing the intake pipe, and is connected to the intake cutoff valve. an auxiliary fuel tank interposed between the overflow opening of the fuel injection pump and the fuel tank and connected to the intake pipe on the downstream side of the intake cutoff valve via a communicating pipe; The actuator includes a liquid level detecting means attached to a fuel tank to detect the fuel liquid level in the tank, and the actuator detects when the engine starter switch is closed and the liquid level detecting means detects the presence of fuel in the auxiliary fuel tank. The intake cutoff valve is closed when the liquid level detection means detects that fuel has flowed into the auxiliary fuel tank due to the closure of the intake cutoff valve. It is characterized by the fact that it operates in such a way as to open the engine, and does not require any special operation when running out of fuel or replacing the fuel filter.
This is extremely convenient because the engine can be automatically primed and started quickly and smoothly by performing a normal starting operation.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Fuel tank, 12... Fuel feed pump, 14... Fuel injection pump, 16... Priming pump, 18... Fuel filter, 2@... Over 7
0-Open"70.32... Auxiliary fuel tank, 34...
Fuel injection nozzle, 42... cylinder, 44... piston, 48... intake valve, 52... intake pipe, 56...
・Main switch, 64...Intake cutoff valve, 68...
Solenoid valve, 72...Liquid level detection switch, 74...Actuator, 7G...Control relay

Claims (1)

[Claims] An intake cutoff valve that is installed in the intake pipe of the engine and restricts the inflow of intake air by closing it, an actuator that is connected to the intake cutoff valve and controls its opening and closing, and an intervening device between the overflow opening of the fuel injection pump and the fuel tank. an auxiliary fuel tank equipped with an auxiliary fuel tank and connected to the intake pipe on the downstream side of the intake cutoff valve via a communication pipe, and a liquid level detection means attached to the auxiliary fuel tank for detecting the fuel liquid level in the tank, The actuator closes the intake cutoff valve when the engine starter switch is closed and the liquid level detection means detects that there is no fuel in the auxiliary fuel tank, and closes the intake cutoff valve. An automatic priming device for an engine, characterized in that the automatic priming device operates to open the intake cutoff valve when the liquid level detection means detects that fuel has flowed into the auxiliary fuel tank.