JP2587067Y2 - Electric oil pump control device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pump control device for a vehicle having an electric oil pump for pumping fuel.

[0002]

2. Description of the Related Art In a vehicle having an electric oil supply pump for pumping fuel from a fuel tank to a fuel supply device, for example, a fuel injection pump, the electric oil supply pump is always provided as long as a starter switch is ON or a start position. Techniques for configuring a pump to operate are known.

However, when the discharge side circuit of the oil feed pump is damaged or the fuel circuit is removed for maintenance of the fuel system, if the starter switch is turned on for any reason,
Fuel may be pumped and overflow, resulting in a fire or other accident.

Japanese Patent Application Laid-Open No. 59-85474 discloses a technique for detecting a current flowing through a motor of a fuel pump in order to detect fuel leakage. However, such a known technique is inaccurate if the relationship between the operating current of the fuel pump and the fuel leakage is not uniquely determined.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric oil feed pump control device that does not reliably operate a pump when a discharge circuit of a fuel system is damaged or a circuit under maintenance is removed. Is to provide.

[0006]

According to the present invention, a pressure sensor for detecting the discharge pressure of the electric oil pump is provided in a vehicle oil pump control device for a vehicle having an electric oil pump for pumping fuel. A control device for controlling the electric oil pump with a signal from the pressure sensor. The control device operates the electric oil pump when the engine is stopped even when the starter switch is turned on. not,
When the starter switch is in the start position, the electric oil pump starts, and the starter switch is turned off while the engine is running.
F, when the engine is stopped with the starter switch on, and when the pressure of the electric oil pump drops and the signal from the pressure sensor falls below a predetermined value. It has the function of not outputting a drive signal to the oil pump.

[0007]

In the electric oil pump control device configured as described above, when the user removes the fuel pipe, for example, due to a failure or maintenance of the fuel pipe, another operator turns on the key switch.
However, since the pipe is disconnected, the discharge side pressure of the oil feed pump does not rise to a predetermined value, and the control device stops the oil feed pump.

As described above, since the discharge pressure of the pump is detected by the pressure sensor, a failure of a pipe or the like can be accurately detected.
The predetermined value of the discharge pressure is set lower than the discharge pressure of the oil pump during operation of the engine, so that there is no problem in operation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an ON terminal of a starter switch 2 is connected to a control device 5, a start terminal of the starter switch 2 is connected to a starter motor 1 and the control device 5, and a diode is provided between both terminals. 6 are connected.

A pulse wheel 4 is attached to a crank pulley (not shown) of the engine, and an engine rotation sensor 3 is connected to a control device 5.

The electric oil pump 7 has one end connected to the control device 5 together with a common terminal of the fuel pressure switch 8 and the other end grounded. The pressure switch 8 is connected to the resistors R5 and R5.
6 and the control device 5 from the middle of the two resistors.
It is connected to the.

FIG. 2 shows a circuit of a specific example of the control device 5,
The control circuit power supply 9 is connected to a battery and has a terminal V
cc is connected to a power supply pin of each IC.

The first Schmitt trigger 10 and the second Schmitt trigger 11 are connected to a first two-input OR 14, and the output side is connected to the CK terminal of the first mono-multi 17. The C terminal of the first mono-multi 17 is a capacitor C
1, the C / R terminal is connected to a terminal Vcc of the control circuit power supply 9 via a resistor R1.

The engine rotation sensor 3 is connected to the CK terminal of the second mono-multi 18 via the amplifier 20, and C, C /
The R terminal is connected to V via a capacitor C2 and a resistor R7.
Connected to cc.

The Q terminal of the first mono-multi is the second, third
The Q terminals of the second mono-multi are input to the third two-input OR via the resistor R8 and the fourth Schmitt trigger 13, and the third Schmitt trigger 12 is connected to the second OR terminal.
Are connected to a two-input OR.

The three-input AND is a second and third two-input O.
R is connected to the output side, and is connected between the resistors R2 and R3, and the output side is connected to the electric oil pump 7 via the resistor R4 and the transistor 21.

The forced drive switch 22 of the oil pump 7 is connected between the battery and the resistor R4, and the transistor 21 is connected to the electric oil pump 7.

The operation will be described below with reference to FIGS.

When the starter switch 2 is turned on, the first mono-multi 17 outputs a drive signal for the pump 7 for a certain period of time and turns on all inputs of the three-input AND 19, so that the transistor 21 is turned on and the pump 7 is driven. But the first
Since the output of the mono-multi 17 is turned off after a predetermined time and the engine is stopped, the output of the fourth Schmitt trigger 13 is turned off and the pump 7 is stopped (FIGS. 4 and 3).
Steps S1 to S11).

Therefore, even if the starter switch 2 is ON, the pump 7 is not driven.

Referring to FIG. 5, when the starter switch 2 is in the starting position, the engine rotates, so that the signal of the engine rotation sensor 3 enters the second mono-multi 18, the fuel pressure switch 8 is set to the H side, and Even if the output of the mono-multi 17 is turned off, the pump 7 continues to operate while the transistor 21 remains conductive (S10 to S1 in FIGS. 5 and 3).
6).

Therefore, the engine can be started by turning the starter switch 2 to the start position.

Next, if any of the following states occurs during operation of the engine, the condition of the output ON of the three-input AND circuit is not satisfied, and the oil feed pump 7 stops.

(1) When the starter switch is turned off, the output of the three-input AND is turned off (S21 in FIGS. 6 and 3).

(2) When the engine is stopped while the starter switch is ON, the output of the third two-input OR is turned OFF (S19 in FIGS. 7 and 3).

(3) If the pressure of the oil feed pump 7 drops or becomes zero for some reason during operation, the fuel pressure switch 8
On the L side and the output of the second two-input OR is turned off (S17, S22, S23 in FIGS. 8 and 3).

Therefore, if there is an abnormality in the fuel circuit, or if the pipe is disconnected for maintenance or the like, the oil feed pump 7 is not driven.

[0029]

[Effects of the Invention] As described above, according to the present invention, the pressure of the discharge side circuit of the pump is detected. Therefore, when the fuel pipe is damaged, or when the fuel pipe is removed for maintenance, etc., the pressure is surely increased. Does not rise. Therefore, the detection is performed accurately. Further, since oil is not fed even when the engine is stopped, it is safe, and it is possible to prevent fuel overflow.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a specific example of the control device of FIG.

FIG. 3 is a flowchart of the control in FIG. 1;

FIG. 4 is a diagram illustrating an operation when the starter switch in FIG. 2 is turned on.

FIG. 5 is a diagram for explaining the operation at the time of starting the engine of FIG. 2;

FIG. 6 is a diagram illustrating an operation when the starter switch of FIG. 2 is turned off.

FIG. 7 is a diagram illustrating an operation when the engine of FIG. 2 is stopped.

FIG. 8 is a view for explaining the operation when the fuel discharge pressure in FIG. 2 is reduced.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Starter motor 2 ... Starter switch 3 ... Engine rotation sensor 4 ... Pulse wheel 5 ... Control device 7 ... Electric oil pump 8 ... Fuel pressure switch 10 ... 1st Schmitt trigger 11 ... 2nd Schmitt trigger 12 ... 3rd Schmidt Trigger 13 Fourth Schmitt trigger 14 First two-input OR 15 Second two-input OR 16 Third three-input OR 17 First monomulti 18 Second monomulti 19 Three-input AND

Claims (1)

(57) [Scope of request for utility model registration] 1. An oil feed pump control device for a vehicle having an electric oil feed pump for feeding fuel under pressure, a pressure sensor for detecting a discharge pressure of the electric oil feed pump is provided, and a signal from the pressure sensor is used to generate a signal from the pressure sensor. A control device for controlling the electric oil pump is provided. When the engine is stopped even when the starter switch is turned on, the electric oil pump is not driven, and when the starter switch is in the start position. The electric oil pump starts and the starter switch is turned off during operation of the engine. The engine stops when the starter switch is turned on. An electric oil pump control device having a function of not outputting a drive signal to the electric oil pump when a signal from the oil pump becomes equal to or less than a predetermined value. .