JPH0442537Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a control device for a fuel pump for an internal combustion engine.

<Prior Art> A conventional example of a control device for a fuel pump for an internal combustion engine is shown in FIG.

That is, a power source U _B such as a battery is connected to an electric motor (not shown) that rotationally drives a fuel pump 1 that pumps fuel to a fuel injection valve or the like of an automobile internal combustion engine.
A transistor 2 and a resistor 3 are connected in series with these.

Then, an operating signal is outputted from the voltage control circuit 5 to the transistor 2 based on a control signal from a control device 4 consisting of a microcomputer or the like. Thereby, the amount of current supplied to the electric motor is controlled based on the engine operating state, and the fuel pump 1 is rotationally driven.

Next, to explain the fuel pump malfunction detection device, a current limiting resistor 8 is connected to the non-inverting terminal of the first comparator 6 and the inverting terminal of the second comparator 7 to detect the voltage between the transistor 2 and the resistor 3. respectively. In addition, the power supply U _B includes first to third voltage dividing resistors 9,
10 and 11 are connected, and the first voltage dividing resistor 9 and the second
The voltage between the voltage dividing resistor 10 (for example, 0.6 V) is applied to the inverting side terminal of the first comparator 6, and the voltage between the second voltage dividing resistor 10 and the third voltage dividing resistor 11 (for example, 0.6 V) is applied to the inverting side terminal of the first comparator 6. 0.1V) is applied to the non-inverting terminal of the second comparator 7.

When an overcurrent flows through the motor due to a foreign object getting stuck in the fuel pump 1, the output of the first comparator 10 becomes H. Further, when the current flowing through the motor becomes less than a predetermined value due to a coil disconnection or the like of the motor, the output of the second comparator 11 becomes H. These first and second
The outputs of the comparators 10 and 11 are input to the self-diagnosis circuit 12 via the control device 4. Self-diagnosis circuit 12
When the output of either the first or second comparator 10 or 11 becomes H, a voltage is applied to the light emitting diode 13 to cause the light emitting diode 13 to emit light to warn of an abnormality in the fuel pump 1 or the electric motor.

<Problems to be solved by the invention> However, in such a conventional fuel pump control device, a disconnection or an overcurrent is detected and the light emitting diode 13 is made to emit light to simply warn of an abnormality in the fuel pump 1 or the electric motor. Since only
If the fuel pump 1 becomes locked due to the foreign matter getting caught in the fuel pump 1, and an overcurrent flows to the electric motor, there is a risk of burnout of the electric motor.

The present invention has been made in view of the above-mentioned circumstances, and provides a control device for a fuel pump for an internal combustion engine that can discharge foreign matter even when the fuel pump gets caught in the foreign matter and prevent burnout of the electric motor. The purpose is to

<Means for Solving the Problems> Therefore, the present invention includes a rotor that is provided in a hollow cylindrical pump housing and forms a predetermined clearance between the rotor and the inner circumferential wall of the pump housing;
an overcurrent detection means configured to freely move one of the pump housing and the other to change the clearance, the overcurrent detection means detecting an overcurrent of a predetermined value or more flowing through an electric motor that rotationally drives a rotor; and when an overcurrent is detected. and a clearance control means for changing the clearance by moving one of the pump housing and the rotor.

<Function> In this way, when an overcurrent flows through the electric motor due to foreign matter being caught, the clearance is changed and the foreign matter is discharged.

<Example> An example of the present invention will be described below with reference to FIGS. 1 and 2. Incidentally, the same elements as those in the conventional example are given the same reference numerals as in FIG. 3, and the explanation thereof will be omitted.

First, the fuel pump will be explained based on FIG. 2. This fuel pump has a rotary pump 22 and an electric motor 23 assembled in a cylindrical casing 21. The rotary pump 22 includes a pump ring 26 provided between a pump base 24 and a pump plate 25, and a fixed shaft 27 provided inside the pump ring 26 and passing through its eccentric position.
a rotor 28 that is rotatable around the rotor 28;
It is composed of roller vanes 29 housed in grooves 28a formed at equal intervals on the outer circumferential surface of the roller vane 29.

The motor 23 has an iron core 3 around the fixed shaft 27.
Armature 30 consisting of 0a and coil 30b
rotates, and a sleeve-shaped joint 32 attached to the end of the armature 30 rotates the rotor 28 via the joint 32 attached to the end of the rotor 28. 33 is magnet, 3
4 is a commutator, 35 is a carbon brush, 36
is a spring for pressing the brush.

The fuel flows in from the inlet 37 of the casing 21, is sucked and discharged by the pump 22, and is supplied from the outlet 38 of the casing 31 to the fuel injection valve (not shown) via the fuel tank 10 (not shown).

Further, as shown in FIG. 1, the pump ring 26 constituting the pump housing is attached to the casing 21 so as to be freely movable in the left and right directions in FIG.
Further, a protrusion 39 formed at one end of the pump ring 26 is connected to the casing 2 through a seal member 40.
1, and a solenoid coil 41 is wound around the outside of this protrusion 39 . One end of the solenoid coil 41 is connected to a power source U _B , and the other end is connected to a collector terminal of a clearance control transistor 42. This transistor 42
The emitter terminal of the transistor 42 is grounded via a current limiting resistor 43, and the base terminal of the transistor 42 is connected to an output terminal of a voltage control circuit 44.

The pump ring 26 is a solenoid coil 41
When the pump ring 26 and the rotor 2 are not energized, the pump ring 26 and the rotor 2 are disposed at the rightmost position in FIG.
The rotor 28 is eccentric so that a minimum clearance C (for example, 10 to 30 μ) with respect to the rotor 28 is formed on the left side of the rotor 28 in FIG. Further, when the solenoid coil 41 is excited, the pump ring 26 moves to the left in FIG. 1, and the minimum clearance increases (eg, 5 mm).

The voltage control circuit 44 controls the transistor 2 based on a control signal from a control device 46 as in the conventional example.
An operating signal is output to the motor 23, and the amount of current supplied to the electric motor 23 is controlled based on the engine operating state. Further, when an overcurrent flows through the motor 23 and the output of the first comparator 6 becomes H, the control device 46 outputs a control signal to the voltage control circuit 44, and the voltage control circuit 44 outputs an H signal to the clearance control transistor 42. .

Incidentally, as in the conventional example, when one of the first comparator 6 and the second comparator 7 outputs an H signal, the self-diagnosis circuit 12
causes the light emitting diode 13 to emit light to issue a warning.

Here, the first comparator 6 constitutes overcurrent detection means, and the control device 45, voltage control circuit 44, transistor 42, and solenoid coil 41 constitute clearance control means.

According to this configuration, if a foreign object gets caught in the part of the minimum clearance C between the pump ring 26 and the rotor 28 and the load on the electric motor 23 becomes large, the electric motor 23
An overcurrent flows. As a result, when the output of the first comparator 6 becomes H, an H signal is output from the voltage control circuit 44 to the transistor 42 via the control device 46. Therefore, the solenoid coil 41 is energized and the pump ring 26 is moved to the left in FIG. be done. When the foreign matter is discharged, the load on the motor 23 becomes smaller, the value of the current flowing through the motor 23 decreases to about the power supply value during normal operation, and the output of the first comparator 6 becomes L. As a result, the transistor 42 is turned off, power supply to the solenoid coil 41 is stopped, and the solenoid coil 41 is de-energized. Therefore, the pump ring 26 is moved to the rightmost position in FIG. 1 by the biasing force of the spring 45 and returns to the minimum clearance C, and normal fuel supply control is performed. In this way, it is possible to prevent the fuel pump from locking up due to foreign matter getting caught, and to prevent burnout of the electric motor.

In this embodiment, the pump ring 26 is moved, but the rotor 28 may be moved to change the clearance. In addition, solenoid coil 4
Hydraulic control may be used instead of 2.

<Effects of the invention> As explained above, the invention changes the clearance between the rotor and the pump housing when an overcurrent is applied to the electric motor that rotates the rotor, thereby preventing foreign objects from forming between them. Since the foreign matter can be discharged when it is caught, it is possible to prevent the fuel pump from locking up and prevent the electric motor from burning out.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing one embodiment of the present invention;
This figure is a sectional view of the same essential parts as above, and FIG. 3 is a configuration diagram showing a conventional example of a control device for a fuel pump for an internal combustion engine. 6...First comparator, 26...Pump ring, 2
8...Rotor, 41...Solenoid coil, 42
...Clearance control transistor, 44...
Voltage control circuit, 46...control device.

Claims (1)

[Scope of utility model registration request] A rotor that forms a predetermined clearance between a hollow pump housing and an inner circumferential wall of the pump housing provided in the pump housing, an electric motor that rotationally drives the rotor, and an amount of electricity supplied to the electric motor is controlled. A control device for a fuel pump for an internal combustion engine, comprising: an energization amount control means, wherein one of the pump housing and the rotor is formed to be freely movable to change the clearance and one of the rotor; Overcurrent detection means for detecting an overcurrent of a predetermined value or more flowing through the electric motor; and clearance control means for moving one of the pump housing and the rotor to change the clearance when the overcurrent is detected. A control device for a fuel pump for an internal combustion engine, characterized in that: