JPH0754725A - Fuel pump control device - Google Patents

Abstract

PURPOSE:To operate a pump at a low voltage while an engine is making its idle run and at full power while it is making high speed run without installing any element which produces energy loss such as a limit resistance and heating in the drive circuit of a fuel pump. CONSTITUTION:When a starter is rotated and an engine is making its idle run, a first comparator 22 is forced to transmit its output by means of the outputs from a one shot multi-vibrator 28 and an integration circuit 29 responding to engine speed, and pulse signals of a specified frequency and duty ratio from a multi-vibrator 20 pass from an OR circuit 24 through an AND circuit 25, and a field effect transistor 26 is controlled by the pulse signals to drive a fuel pump at a specified duty ratio. When the engine speed is high, because a second comparator 23 makes its action and the OR circuit and AND circuit output '1', the field effect transistor 26 drives the fuel pump at a duty ratio of 100% and at continuous full power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump controller for supplying fuel to an engine mounted on a vehicle or the like.

[0002]

2. Description of the Related Art FIG. 17 is a circuit diagram of a conventional fuel pump control device disclosed in, for example, Japanese Utility Model Laid-Open No. 61-7827, in which 1 is a storage battery of a vehicle, 2 is an ignition switch, 3 is a starter, and 4 is a starter. Is a starting relay, 5 is an ignition coil, 6 is an igniter, and a transistor 7 is incorporated therein. A control relay 8 is composed of a contact 8a and an exciting coil 8b which are connected in parallel with the control resistor 9.

An electronic control unit 10 has a CPU 10a,
It is composed of a transistor 10b and a transistor 10c, and 11 is a fuel pump relay composed of a contact 11a and an exciting coil 11b. 12 is a fuel pump.

Next, the operation will be described. When the ignition switch 2 is turned to the ST position, a current is passed from the storage battery 1 to the exciting coil 4a of the starting relay 4 and thereby the contact 4b.
Closes and starter 3 starts. As a result, the transistor 7 of the igniter 6 is turned ON-O in a known manner.
After being FFed, the ignition coil 5 generates a high voltage and the engine (not shown) rotates. At this time, the starter motor signal and the igniter signal are input to the electronic control unit 10, and the CPU 10a performs the calculation.

As a result, when the starter 3 is rotating, the transistors 10b and 10 in the electronic control unit 10 are
is controlled by the CPU 10a so that both c are electrically connected,
A current flows from the storage battery 1 to the fuel pump 12 through the ignition switch 2, the contact 8a, and the contact 11a, and the fuel pump 12 is driven by the supply voltage (12V) of the storage battery 1.

When the engine speed is idling (500-
At 900 rpm, the transistor 10b is turned off and the transistor 10c is turned on.
Controlled by the fuel pump 12, a current flows from the storage battery 1 through the ignition switch 2, the control resistor 9, and the contact 11a, and the fuel pump 12 subtracts the reduced voltage at the control resistor 9 from the supply voltage of the storage battery 1 ( It is driven by about 8V).

When the engine speed becomes high (2000 rpm or more), the transistor 10b is turned on by the action of the CPU 10a, and the fuel pump 12 is driven by the supply voltage (12V) of the storage battery 1 as when the starter 3 is rotating.

FIG. 18 is a time chart showing the above operation. A is an ON-OFF voltage waveform of the transistor 7 of the igniter 6, B is a drive voltage waveform of the starter 3, and C is a supply voltage to the fuel pump motor. It is a waveform.

[0009]

Since the conventional fuel pump control device is constructed as described above, the voltage drop of the control resistor 9 is utilized during idling to decrease the supply voltage to the pump. There were problems such as energy loss and heat generation in the control resistor.

The present invention has been made in order to solve the above problems, and eliminates the control resistance to prevent energy loss and heat generation, and increases the rotational speed of the fuel pump at the time of starting the fuel pump. However, it is an object of the present invention to provide a fuel pump control device that does not cause a shortage of fuel supply pressure.

[0011]

A fuel pump control device according to the present invention outputs a first mode signal during rotation of a starter and during idling of an engine in accordance with an ignition signal of the engine or an engine speed. Engine rotation mode detecting means for outputting a second mode signal when the engine is rotating at high speed, pulse generating means for outputting a pulse signal having a predetermined cycle and a predetermined duty ratio, and inputting the first and second mode signals and the pulse signal As a signal, a logic circuit that outputs a pulse signal of the above-mentioned predetermined cycle and a predetermined duty ratio during starter rotation and engine idling, and outputs a continuous signal during high engine rotation, and energization control of the electric fuel pump according to the output of this logic circuit And a switching element for switching.

Engine rotation mode detecting means for outputting a first mode signal when the engine is idling and outputting a second mode signal when the engine is rotating at a high speed according to an engine ignition signal or an engine speed. A pulse generator that outputs a pulse signal having a predetermined cycle and a predetermined duty ratio, the first and second mode signals, the pulse signal, and a signal corresponding to the voltage applied to the engine starter are used as input signals, and the predetermined signal is used when the engine is idling. While outputting a pulse signal with a cycle and a predetermined duty ratio,
A logic circuit that outputs a continuous signal when the starter rotates and when the engine rotates at high speed, and a switching element that controls energization of the electric fuel pump according to the output of the logic circuit are provided.

According to the ignition signal of the engine or the engine speed, a first mode signal is output when the starter is rotating, a second mode signal is output when the engine is idling, and a third mode signal is output when the engine is rotating at a high speed. Engine rotation mode detecting means for outputting a mode signal, pulse generating means for outputting a pulse signal having a predetermined cycle and a predetermined duty ratio,
The first, second, and third mode signals and the pulse signal are used as input signals, and a pulse signal having the above-described predetermined cycle and a predetermined duty ratio is output during engine idling, and a continuous signal is output during starter rotation and high engine rotation. A logic circuit for outputting and a switching element for controlling energization of the electric fuel pump according to the output of the logic circuit are provided.

Further, an engine rotation level detecting means for outputting an ignition signal of the engine or a level signal corresponding to the number of revolutions of the engine, a starter signal corresponding to a voltage applied to the engine starter, and the level signal are inputted. It is provided with a control element for controlling energization of the electric fuel pump according to the level of the signal.

[0015]

The fuel pump control device according to the present invention outputs the first mode signal output when the starter is rotating and when the engine is idling, and when the engine is rotating at high speed, according to the ignition signal of the engine or the engine speed. The second mode signal to be generated and the pulse signal having the predetermined cycle and the predetermined duty ratio from the pulse generating means are input to the logic circuit to generate the pulse signal having the predetermined cycle and the predetermined duty ratio during the starter rotation and the engine idling. In addition to the output, a continuous signal is output when the engine is rotating at high speed, and the switching element energizes the electric fuel pump according to this output.

Further, according to the engine ignition signal or the engine speed, a first mode signal output when the engine is idling, a second mode signal output when the engine is rotating at high speed, and pulse generating means. A pulse signal of a predetermined cycle and a predetermined duty ratio from, and a signal corresponding to the voltage applied to the engine starter is input to the logic circuit, and at the time of engine idling, a pulse signal of the predetermined cycle and a predetermined duty ratio is output, When the starter is rotating and the engine is rotating at high speed, a continuous signal is output, and the switching element energizes the electric fuel pump according to this output.

A first mode signal output during starter rotation and a second mode output during engine idling and during engine rotation above idling in accordance with the engine ignition signal or the engine speed. A signal, a third mode signal output at the time of high engine rotation, and a pulse signal having a predetermined cycle and a predetermined duty ratio from the pulse generating means are input to a logic circuit, and at the time of engine idling, the predetermined cycle and the predetermined duty ratio. And a continuous signal at the time of starter rotation and at high engine speed, and the switching element controls the electric fuel pump to be energized according to this output.

Further, a level signal corresponding to the engine ignition signal or the engine speed and a starter signal corresponding to the voltage applied to the engine starter are input to the control element, and when the starter signal is input and the engine is rotating at high speed, The control element is set to a high-conduction output state, and when the engine is idling, the control element is set to a low-conduction output state to control conduction of the electric fuel pump.

[0019]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 to 7 and 12 are the same as the conventional one shown in FIG. 20 is 20-100K
It is a multivibrator that oscillates a pulse of Hz, and a signal having a duty ratio of 60 to 70% is output through the diode 21. Reference numeral 26 is a field effect transistor used to control the duty of the fuel pump 12. Numeral 28 is a one-shot multivibrator consisting of an operational amplifier, a resistor, a capacitor, and a diode. When the engine is rotating, every time the transistor 7 of the igniter 6 generates an ON signal (the voltage becomes 0V), it is triggered through the diode 27 and is a one-shot signal. Is generated, and in this example, the signal has a constant width with a pulse width of about 5 to 10 ms. Reference numeral 29 is an integrating circuit including a resistor 29a and a capacitor 29b.

The operation of the fuel pump control device having the above construction will be described with reference to FIGS. When the ignition switch 2 is turned on (IG position), the voltage at the point A is the voltage of the storage battery 1 (12
V). At this time, the transistor 7 of the igniter 6 is configured to be turned off. Therefore, the output voltage (point B) and the voltage at point C of the one-shot multivibrator 28 are 0V. Therefore, the first comparator 22 and the second comparator 23 do not output.

At this time, the multi-vibrator 20 has 20-
A pulse with a duty ratio of 60 to 70% at 100 KHz is shown in FIG.
Since it oscillates like D, the output of the OR circuit 24 (E
As the voltage of the point), a pulse having the same duty ratio as the output of the point D is output. However, this pulse output is AND circuit 2
Since the output of the first comparator 22 of 5 is "0", the output is also "0". Therefore, the field effect transistor 26
However, the F point voltage is 12V and the fuel pump 12 does not operate.

Next, when the ignition switch 2 is turned to the ST position, a current is supplied from the storage battery 1 to the exciting coil 4a of the starting relay 4, whereby the contact 4b is closed and the starter 3 is started. As a result, the transistor 7 of the igniter 6 is turned on and off, the ignition coil 5 generates a high voltage, and the engine rotates. The voltage waveform of each part when the starter is rotated 3 times is as shown in FIG.
A pulse having a pulse width of 10 ms) is generated. This pulse is generated every time the transistor 7 is turned on, and this pulse voltage is generated by the integrating circuit 2 including the resistor 29a and the capacitor 29b.
It is integrated at 9 and becomes a constant voltage of 1 V or more. Since this voltage is higher than the voltage of the negative terminal of the first comparator 22,
Is output from the comparator 22.

On the other hand, the output of the multivibrator 20 is
Since the second comparator 23 does not output, the pulse output at point D passes through the OR circuit 24 and is output as a pulse voltage at point E. Since the output of the first comparator 22 and the pulse output at the point E are input to the AND circuit 25,
The pulse output at point E is output. That is, the pulse of 20 to 100 KHz generated at the point D is the field effect transistor 2.
6 is applied as a gate voltage. As a result, the field-effect transistor 26 is duty-controlled with the above pulse,
A voltage is applied as indicated by the dotted line at point F, and the fuel pump 12 is driven at an average voltage of 8V.

Next, the engine is started and idling (50
(0 to 900 rpm), the ON-OFF frequency of the transistor 7 of the igniter 6 increases, so the number of pulses generated at the B point increases, and the integrated voltage at the C point becomes 3
It becomes as high as V. However, the second comparator 23 is 5V
Therefore, the fuel pump 12 is not operated at 3V, and the fuel pump 12 is controlled and operated at a duty ratio of 60 to 70% as in the operation when the starter rotates.

When the engine speed becomes high, the number of pulses generated at the point B increases, and the potential at the point C rises to 5 V.
That is all. Therefore, the second comparator 23 outputs and the output at the point E of the OR circuit 24 continuously outputs "1". That is, this output is output regardless of the presence or absence of the pulse signal of the multivibrator 20. Since the inputs of the AND circuit 25 are both "1", the output is also "1" and the field effect transistor 26 is continuously turned on. As a result,
The fuel pump 12 is operated at a duty ratio of 100%.

In this way, since there is no resistance element of the control resistor 9 as in the prior art, there is no wasted energy consumption and no heat is generated. Also, because there are no contacts in the circuit,
High reliability can be obtained without contact failure or welding.
Furthermore, when the starter is rotating and idling (500-9
(00 rpm), it acts to lower the supply voltage to the fuel pump (about 8 V), which reduces the power consumption of the fuel pump and reduces the motor vibration when the fuel pump motor is operating. Pump operating noise is low.

The logic circuit composed of the AND circuit 24 and the OR circuit 25 in FIG. 1 does not necessarily have this configuration. FIG. 3 shows an example thereof, and FIG. 3a shows the logic circuit of FIG.
b is a modification thereof. This is shown in a logical expression in FIG.
Is (a + c) (b + c) = ab + ac + bc + cc = a
(B + c) + c, and the output on the right side is shown in FIG. 3b. In this formula, since bc does not become "1" at the same time, the logical product becomes "0" and cc = c.

In addition to this, the first embodiment can be constituted by two OR circuits by inhibiting the output of the first comparator with the output of the second comparator. In this case, an inhibit circuit may be provided, but the output of the second comparator is used to output the first
The negative terminal of the comparator may be biased. For example, the output of the second comparator is biased to the negative terminal of the first comparator through a diode and a resistor. Thus, the logic circuit can be configured in various ways.

Further, although the first and second comparators are used in the first embodiment, the AND circuit 25 operates at 1V and OR
If the circuit 24 uses a logic circuit operating at 5V, the comparator can be eliminated.

FIG. 4 is a block diagram of the first embodiment, and 101 is a pulse generating means (corresponding to the multivibrator 20) for generating a pulse signal having a predetermined frequency and a predetermined duty ratio.
Reference numeral 102 denotes an engine rotation mode detecting means, which comprises a level converting means 103 (corresponding to the one-shot multivibrator 28 and the integrating circuit 29) and a comparing means 104 (corresponding to the first and second comparators 22 and 23). Input a signal or a signal according to the engine speed,
The signal of the mode, that is, the signal when the engine is rotating at a low speed (when the starter is rotating and the engine is idling) and the second mode signal, that is, the signal when the engine is rotating at a high speed are output.

The logic circuit 105 outputs a pulse signal having a predetermined duty ratio when the engine speed is low and a continuous signal having a duty ratio of 100% when the engine speed is high in response to the input of the pulse signal and the first and second mode signals. Is output. The switching element 106 controls energization of the fuel pump 107 according to this output.

Example 2. In the first embodiment, the duty control means is described as being composed of the one-shot multivibrator and the multivibrator using the engine speed pulse as a trigger signal. However, an embodiment in which not only the above signals but also a starter signal is used in FIG. This will be described with reference to FIG.

When the ignition switch 2 is turned on at the time of rotation of the starter, the voltage at the point G becomes 12V, and the OR circuit 31 outputs "1". On the other hand, the pulse output of the one-shot multivibrator 28 causes the integration circuit 29 to
The voltage of the point C integrated into the first comparator 22
Is output and "1" is given to the AND circuit 25.
The D circuit 25 produces a logical product of 1 × 1 and outputs “1”.
As a result, the field effect transistor 26 is brought into a completely conductive state, and the fuel pump 12 is operated at a 100% duty ratio as shown in FIG. 6F.

The operation is the same as that of the first embodiment when the engine is idling and when the engine is rotating at a high speed, and a description thereof will be omitted. Comparing the second embodiment with the first embodiment, the discharge performance of the fuel pump 12 during rotation of the starter is improved, so that the engine startability can be improved.

The logic circuit of FIG. 5 is shown in FIG. 7a, a modification of which is shown in FIG. 7b. To explain this using a logic circuit, FIG. 7A shows that (a + c + d) (b + c) = (a + c) (b + c) + d.
(B + c) = (a + c) (b + c) + db + dc = (a
+ C) (b + c) + d, which is the output of FIG. 7b. In this equation, the right side is the same as the output of the first embodiment (FIG. 3a), and an OR circuit that receives this output and d may be provided. Note that db = d is sufficient,
Since dc does not become "1" at the same time, dc = 0.

Since the first term of (a + c) (b + c) + d is the circuit of the first embodiment (FIG. 3a), it becomes the logic circuit of FIG. 3b. Therefore, (a + c) (b + c) + d = a (b +
c) + c + d, which may be the logic circuit of FIG. This logic circuit corresponds to FIG. 3b with the input of d added.

When actually forming a logic circuit, NO
Although it is often configured by an R circuit, in this case, the NOR circuit alone can be configured by using the logic circuit of FIG. This logical formula is also shown in FIG.
As shown in.

FIG. 10 is a block diagram of the second embodiment. Compared to the block diagram of the first embodiment in FIG. 4, the ignition switch ST signal is input to the logic circuit 105. Further, the first mode signal of the engine rotation mode detection means 102 is output during low engine speed (starter rotation and engine idling) or only during engine idling. Further, the output of the logic circuit 105 is an output with a predetermined duty ratio when the engine is idling, and is a continuous output with a duty of 100% when the starter is rotating and the engine is rotating at high speed.

Example 3. As a case of performing duty control similar to that in the second embodiment, ST of the ignition switch 2 is used.
An embodiment in which no signal is used is shown in FIGS. In the figure, the first, second and third comparators 22, 33,
34 are provided so that they are output when there is an input of 1 V, 3 V, 5 V or more, respectively. 32 is a NOT circuit,
This is an inverter that inverts the pulse signal of the multivibrator 20. Since the inverted pulse signal is inverted again when the NAND circuit 35 outputs, the pulse signal having the duty ratio of the multivibrator 20 is restored.
36 is an AND circuit and 37 is an OR circuit.

Next, the operation will be described. When the starter is rotating, the output of the point C is 1V and the first comparator 22 operates to output the first mode signal H. This output is N
The AND circuit 36 outputs 1 and the AND circuit 36 outputs 1
+1 is input, "1" is output, the field effect transistor 26 is continuously turned on through the OR circuit 37, and the fuel pump 12 is driven by the voltage of 12V like the voltage at the point F in FIG.

When the engine is idling, the voltage at point C is 3
Since V is output, the first and second comparators 22, 3
3 is activated, and the first mode signal H and the second mode signal J
Is output. With the second mode signal J, the NAND circuit 35 outputs a pulse signal having the same duty ratio as that of the multivibrator 20. Since this pulse signal and the first mode signal H are inputted to the AND circuit 36, this pulse signal is outputted as the output of the AND circuit 36, and the field effect transistor 26 is passed through the OR circuit 37 at a predetermined duty ratio. It is made conductive, and the fuel pump 12 is driven like the voltage at point F in FIG.

When the engine is rotating at high speed, the voltage 5V at the point C is output, so that all the first, second and third comparators 2 are provided.
2, 33, 34 are activated and the first, second, and third mode signals H, J, I are output. The third mode signal I is OR
Since it is input to the circuit 37, the output of the OR circuit 37 becomes "1" and the field effect transistor 26 is continuously conducted at a duty ratio of 100%, and the fuel pump 12 is driven at 12V like the voltage at point F in FIG. .

FIG. 13 is a block diagram of the third embodiment. The difference from the block diagram of the second embodiment of FIG. 10 is that the output of the engine rotation mode detection means 102 outputs the first, second and third mode signals, and the ST of the ignition switch is turned on.
This is the point where the signal was lost.

Example 4. Although the duty control is performed using the field effect transistor, analog control may be performed using the transistor. This Embodiment 4 is shown in FIG.
It shows in FIG. In FIG. 14, reference numeral 41 denotes a power transistor to which the ST signal (G) of the ignition switch and the output (C) from the integrating circuit 29 are input, and the fuel pump 12 is energized and controlled according to the input signal level.

Next, the operation will be described. When the starter is rotating, a voltage signal of 5 V or more as shown in FIG. 15G is input to the power transistor 41.
Conducts at a high level and the fuel pump 12
It is driven by V. During engine idling, the signal at point C becomes 3V, the power transistor 41 conducts at a low level, and the fuel pump 12 is driven at 8V like F.
When the engine is rotating at high speed, the signal at point C becomes 5V, the power transistor 41 conducts at a high level, and the fuel pump 12 is driven at 12V like F.

In this embodiment, the output level of the output side of the integrator circuit 29 changes stepwise as shown in FIG. 15c. You may aim at stabilization. On the contrary, in the first to third embodiments, even if the comparator (comparing means) is omitted, the output level is changed stepwise as shown in FIG. 15c, so that the logic circuit can be driven.

FIG. 16 is a block diagram of the fourth embodiment. The comparing means 203 of the engine rotation level detecting means 201,
It may be added as described above. Control element 204
May be one that outputs according to the input level of the power transistor 41 and the like.

[0048]

As described above, according to the present invention, since the control resistor is eliminated in the fuel pump drive circuit, there is an effect of eliminating energy loss and heat generation in the control resistor.

Further, since the control device detects the engine rotation mode and controls the fuel pump by the duty ratio according to this mode, it operates at low voltage during idling.
Full power operation is performed during starter rotation and high rotation, which has the effect that the fuel supply pressure does not become insufficient at engine start.

Further, since the signal at the time of rotation of the starter and the signal according to the number of revolutions of the engine are input to the control element such as a transistor and the fuel pump is driven by the output according to this input level, the control is performed. Since there is no resistance, there is an effect of eliminating energy loss in the control resistance and generation of heat generation.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of a fuel pump control device according to a first embodiment of the present invention.

FIG. 2 is a time chart of the operation of the first embodiment.

FIG. 3 is a logic circuit diagram of a modified example according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a fuel pump control device according to the first embodiment of the present invention.

FIG. 5 is an electric circuit diagram of a fuel pump control device according to a second embodiment of the present invention.

FIG. 6 is a time chart of the operation of the second embodiment.

FIG. 7 is a logic circuit diagram of a modified example according to the second embodiment of the present invention.

FIG. 8 is a logic circuit diagram of a modified example according to the second embodiment of the present invention.

FIG. 9 is a logic circuit diagram of a modified example according to the second embodiment of the present invention.

FIG. 10 is a block diagram of a fuel pump control device according to a second embodiment of the present invention.

FIG. 11 is an electric circuit diagram of a fuel pump control device according to a third embodiment of the present invention.

FIG. 12 is a time chart of the operation of the third embodiment.

FIG. 13 is a block diagram of a fuel pump control device according to a third embodiment of the present invention.

FIG. 14 is an electric circuit diagram of a fuel pump control device according to a fourth embodiment of the present invention.

FIG. 15 is a time chart of the operation of the fourth embodiment.

FIG. 16 is a block diagram of a fuel pump control device according to a fourth embodiment of the present invention.

FIG. 17 is an electric circuit diagram of a conventional fuel pump control device.

FIG. 18 is a time chart of the operation of the conventional fuel pump control device.

[Explanation of symbols]

 1 Storage Battery 2 Ignition Switch 3 Starter 4 Start Relay 4a Excitation Coil 4b Contact 5 Ignition Coil 6 Igniter 7 Transistor 8 Control Relay 8a Contact 8b Excitation Coil 9 Control Resistor 10 Electronic Control Unit 10a CPU 10b Transistor 10c Relay 11a Fuel Pump 11b Excitation coil 12 Fuel pump 20 Multivibrator 21 Diode 22 First comparator 23 Second comparator 24 OR circuit 25 AND circuit 26 Field effect transistor 27 Diode 28 One-shot multivibrator 29 Integration circuit 29a Resistor 29b Capacitor 31 OR circuit 32 NOT circuit 33 second comparator 34 third comparator 35 NAND circuit 36 AND circuit 3 OR circuit 41 a power transistor 101 pulse generating means 102 engine mode detector 103 level conversion means 104 comparator means 105 logic circuit 106 switching element 107 fuel pump 201 engine level detecting means 202 level conversion means 203 comparator means 204 control device 205 fuel pump

Claims (4)

[Claims] 1. An engine which outputs a first mode signal when the starter is rotating and when the engine is idling and which outputs a second mode signal when the engine is rotating at high speed according to an ignition signal of the engine or an engine speed. Rotation mode detecting means, pulse generating means for outputting a pulse signal having a predetermined cycle and a predetermined duty ratio, the first and second mode signals and the pulse signal as input signals, and the predetermined cycle at starter rotation and engine idling. Fuel pump control including a logic circuit that outputs a pulse signal with a predetermined duty ratio and outputs a continuous signal when the engine is rotating at high speed, and a switching element that controls energization of the electric fuel pump according to the output of this logic circuit apparatus. 2. An engine rotation mode detecting means for outputting a first mode signal when the engine is idling and outputting a second mode signal when the engine is rotating at high speed according to an engine ignition signal or an engine speed. A pulse generator that outputs a pulse signal having a predetermined cycle and a predetermined duty ratio, the first and second mode signals, the pulse signal, and a signal corresponding to the voltage applied to the engine starter are used as input signals, and the predetermined signal is used when the engine is idling. A logic circuit that outputs a pulse signal with a cycle and a predetermined duty ratio, and that outputs a continuous signal during starter rotation and high engine rotation, and a switching element that controls energization of the electric fuel pump according to the output of this logic circuit are provided. Characteristic fuel pump control device. 3. A first mode signal is output when the starter is rotating, a second mode signal is output when the engine is idling, and a third mode signal is output when the engine is rotating at high speed according to an engine ignition signal or an engine speed. Engine rotation mode detecting means for outputting the mode signal, pulse generating means for outputting a pulse signal having a predetermined cycle and a predetermined duty ratio, the first, second and third mode signals and the pulse signal as input signals, At the time of idling, while outputting a pulse signal of the above-mentioned predetermined cycle and a predetermined duty ratio,
A fuel pump control device comprising: a logic circuit that outputs a continuous signal during starter rotation and high engine rotation; and a switching element that controls energization of an electric fuel pump according to the output of this logic circuit. 4. An engine rotation level detecting means for outputting an engine ignition signal or a level signal according to the engine speed, a starter signal corresponding to a voltage applied to an engine starter, and the level signal are inputted. Equipped with a control element that controls the electric fuel pump to be energized according to the signal level.When the starter signal is input and the engine is rotating at high speed, the control element is set to a high-conduction output state, and when the engine is idling, the control element is set to a low-conduction output state and the electric drive A fuel pump control device, characterized in that a fuel pump is controlled.