JP2002303185A - Controller for electromagnetic load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller for an electromagnetic load capable of preventing an overcharging at the time of occurrence of a short-circuit of a power supply. SOLUTION: An energy supplied to the solenoids 11, 12, and 13 of an injector is accumulated in a capacitor C1, and transistors Q2, Q11, Q12, and Q13 are controlled by inputted injection signals TQ1, TQ3, and TQ to supply the energy stored in the capacitor C1 to the solenoids 11, 12, and 13. A fly-back energy occurring at the time of interruption of energization is returned to energy collecting diodes D11, D12, and D13 and the capacitor C1. When over-voltage detection signals are outputted and over-current detection signals are outputted, the energization is stopped by an AND gate 50 even if injection signals TQ1, TQ3, and TQ5 are inputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electromagnetic load, and more particularly, to an operation response (for example, a valve opening response of an injector, that is, a fuel injection solenoid valve) by discharging energy stored in a capacitor. The present invention relates to an improved electromagnetic load control device.

[0002]

2. Description of the Related Art Conventionally, a booster circuit (DC-DC converter) discharges energy stored in a capacitor in order to speed up a valve opening response of an electromagnetic valve, or
There is known a device that accumulates energy in a capacitor by recovering energizing energy of a solenoid valve and uses the energy (Japanese Patent Application Laid-Open No.
-115727, JP-B-7-78374,
Japanese Patent No. 2598595).

An example of this type of electromagnetic load control device is shown in FIG.
Shown in FIG. 3 shows an injector control device (drive circuit 10).
0) is an electric circuit diagram, and FIG. 4 shows a timing chart thereof.

In the driving circuit 100 shown in FIG. 3, a capacitor 103 is connected to a solenoid 101 of an injector via a transistor 102, and a power supply + B is connected via a transistor 104.
Is formed by a peak current Ip and two-stage constant currents I1 and I2, as shown in FIG.
The charging capacitor 103 in FIG.
5 to 130 volts and discharge control circuit 106
Generates a peak current Ip. Subsequently, the constant current control circuit 107 generates two-stage constant currents I1 and I2. Further, an energy recovery diode 108 is inserted in the middle of a path connecting the injector terminal 113 and the charging capacitor 103 for charging using flyback energy of the solenoid 101 of the injector.

In the circuit diagram of FIG. 3, the charging voltage is usually controlled to about 130 volts by the operation of the charging voltage control circuit 105. The charge overvoltage detection circuit 109 monitors this charge voltage. If the charge voltage becomes 150 volts or more due to any abnormality, the charge overvoltage detection circuit 109 determines that the charge circuit is abnormal and sends a charge overvoltage detection signal to the charge voltage control circuit 105. And stop the charging operation.

On the other hand, there is another operation for increasing the charging voltage other than the charging voltage control circuit 105, which is energy recovery. This is because flyback occurs when the current of the solenoid 101 of the injector is suddenly cut at the moment when the injection signals (injector drive signals) TQ1, TQ3, and TQ5 are turned off from the on state (timing at t110 and t111 in FIG. 4). The charging voltage is raised by recovering energy to the charging capacitor 103 by the energy recovery diode 108. Thus, by effectively utilizing the current flowing through the solenoid 101 of the injector, the load on the charging voltage control circuit 105 is reduced, and the effect of suppressing heat generation is provided.

However, when this energy recovery operation is performed, troublesome operation may be performed when the injector is abnormal. Now, for example, when a power short-circuit occurs at the common terminal 110 in FIG. 3 (timing at t100 in FIG. 4), a current much larger than the normal current flows, and
Injector overcurrent detection circuit 11 at timing 120
1 (see FIG. 3) operates and the injection signals TQ1, TQ3, TQ
5 (transistor gate signal TWV) is cut off (overcurrent detected at t120 in FIG. 4, cut off at t121).

However, the flyback energy of the overcurrent is also recovered by the charging capacitor 103 through the energy recovery diode 108. When the injection signals TQ1, TQ3, and TQ5 are continuously input in this state, the charge voltage is reduced because the charge is discharged to the solenoid 101 of the injector at the rising edge, but the charge voltage decreases (at timings t122 and t124 in FIG. 4). ), FIG.
In the falling edges shown at t123 and t125, the flyback energy larger than that at the time of discharging is charged (ΔV2> ΔV1). As a result, the charging voltage increases. Therefore, an overcharge state occurs, and the charge overvoltage detection circuit 109 operates to stop the charging operation. This is because the charge voltage control circuit 105 is not abnormal and the power supply is short-circuited. Therefore, as long as the power supply short-circuit state does not disappear, even if the charging operation is stopped, the charging voltage does not stop increasing due to the overcurrent flyback recovery, and the charging voltage continues to increase.

Finally, the charging transistor 1 shown in FIG.
The voltage rises to 200 volts, which is the breakdown voltage of 12 (timing at t126 in FIG. 4), and is maintained. This situation is undesirable.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic load control device capable of preventing overcharging when a power supply short circuit or the like occurs.

[0011]

According to the first and second aspects of the present invention, the charging means performs the charging operation of the capacitor and stores the energy supplied to the electromagnetic load. The energy stored in the capacitor by the switching element is supplied to the electromagnetic load by the input ON signal. Flyback energy generated when the power supply to the electromagnetic load is cut off is returned to the capacitor by the energy recovery diode.

On the other hand, when the charging voltage at the capacitor is detected by the first prohibiting means and the charging voltage exceeds a predetermined value, an overvoltage detection signal is output and the charging operation of the capacitor by the charging means is stopped. Further, the second prohibiting means detects a current value flowing through the electromagnetic load and, when the current value exceeds a predetermined value, outputs an overcurrent detection signal and terminates energization of the electromagnetic load by the current ON signal on the way. You.

Here, when a short circuit occurs in the power supply line to the electromagnetic load, a large current flows through the electromagnetic load, and the current supply to the electromagnetic load by the current ON signal is terminated halfway by the second inhibiting means. However, the flyback energy generated when the power supply to the electromagnetic load is cut off is returned to the capacitor by the energy recovery diode and becomes overcharged, and the charging operation of the capacitor is stopped by the first inhibiting means. , The charging voltage of the capacitor will continue to rise.

Here, in the present invention, when the overvoltage detection signal is output and the overcurrent detection signal is output by the third inhibiting means, the energization of the electromagnetic load is stopped even if an ON signal is input. Can be As described above, according to the present invention, when a power supply short circuit or the like occurs in the energy supply line to the electromagnetic load, the operation itself of the electromagnetic load is performed when the overvoltage detection signal is output and the overcurrent detection signal is output. Stopped. As a result, it is possible to prevent the charging voltage of the capacitor from increasing due to the energy recovery diode.

Here, as the second prohibiting means, a memory for inputting an overcurrent detection signal as a set signal and outputting a command signal for terminating energization to the electromagnetic load in the middle as the second prohibiting means. In the electromagnetic load control device provided with the holding means, as the third prohibiting means, an ON signal is input, a signal obtained by inverting the overvoltage detection signal is input, and its logical product is output as a reset signal of the memory holding means. An AND gate is preferably used.

Further, the electromagnetic load can be applied to a control device of an electromagnetic load which is a solenoid of an injector for supplying fuel to an engine.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is embodied as a common rail fuel injection system for a vehicle-mounted six-cylinder diesel engine. Injection is supplied to each cylinder.

FIG. 1 is an electric circuit diagram showing an injector control device (drive circuit 1) for one bank in the present embodiment. That is, this is an apparatus (1) for driving the injectors of the first, third, and fifth cylinders, and of the second, fourth, and sixth cylinders having the same configuration as that of the injector drive circuit 1 of FIG. A device for driving the injector is provided.

The apparatus shown in FIG. 1 includes solenoids 11, 12, and 13 of injectors for supplying (injecting) fuel to first, third, and fifth cylinders of the engine, and solenoids 11, 12, and 13 of each injector. Drive circuit 1 for driving the motor, and E connected to the injector drive circuit 1
A CU (electronic control unit) 2. The ECU 2 uses the CP
U, a well-known microcomputer including various memories, etc., and injection signals TQ1 and TQ for each cylinder based on engine operation information detected by various sensors such as an engine speed Ne, an accelerator opening ACC, and an engine coolant temperature THW.
3, TQ5 is generated and output to the injector drive circuit 1.

Each injector is constituted by a normally closed solenoid valve (three-way solenoid valve), and a solenoid 1 as an electromagnetic load is provided.
1, 12, 13 are provided. In this case, the solenoid 11,
When the power is supplied to the valves 12 and 13, the valve body (not shown) moves to the valve opening position against the urging force of the return spring, and the fuel is injected. Further, when the energization of the solenoids 11, 12, and 13 is cut off, the valve body returns to the original valve closing position, and the fuel injection is stopped.

The charging coil (inductor) L1 has one end connected to the vehicle power supply + B and the other end connected to the transistor (switching element) Q1. Hereinafter, all the transistors are used as switching elements. The charging voltage control circuit 20 is connected to the gate terminal of the transistor Q1, and the transistor Q1 is turned on / off according to the output of the circuit 20. More specifically, the charging voltage control circuit 20 uses a self-excited oscillation circuit. Further, a current detection resistor R1 is connected between the transistor Q1 and GND.

One end of a capacitor C1 is connected between the charging coil (inductor) L1 and the transistor Q1 via a diode D1 for preventing backflow. The other end of the capacitor C1 is connected to a transistor Q1 and a current detection resistor R1.
Is connected between.

The charging coil (inductor) L1, transistor Q1, current detection resistor R1, charging voltage control circuit 20, and diode D1 constitute a DC-DC converter circuit as charging means for charging the capacitor C1. . When the transistor Q1 is turned on / off, the capacitor C1 is charged through the diode D1. As a result, the capacitor C1 is charged to a voltage higher than the in-vehicle power supply voltage, and can store energy higher than the in-vehicle power supply + B. In such a case, the transistor C1 is turned on / off by the charging voltage control circuit 20 while the charging current is monitored by the current detection resistor R1, so that the capacitor C1 is charged at an efficient cycle. In this way, the charging voltage is controlled to about 130 volts by the operation of the charging voltage control circuit 20.

A charge overvoltage detection circuit 21 as a first prohibiting means detects a charge voltage at the capacitor C1 and, when the charge voltage exceeds a predetermined value (150 volts), sends a charge overvoltage detection signal to the charge voltage control circuit 20. Output to stop the charging operation of the capacitor C1.

A common terminal 1a is connected to the capacitor C1 via a transistor Q2 and a diode D2, and the common terminals 1a are connected to the solenoids 11, 1 of each injector.
2 and 13 are respectively connected. Further, the terminals 1b, 1c and 1d of each injector are connected to the transistor Q1.
1, Q12 and Q13 are grounded. And
Both transistors Q2 and Q11 turn on, or
Both transistors Q2 and Q12 turn on, or
When both the transistors Q2 and Q13 are turned on, the energy stored in the capacitor C1 is transferred to the solenoid 1 of the injector.
It is supplied (discharged) to 1, 12, and 13. Due to such energy release of the capacitor C1, a large current flows as a driving current for the injector, and accordingly, the valve opening response of the injector is improved.

In the injector driving circuit 1, the common terminal 1a is connected to the vehicle power supply + B via the transistor Q3 and the diode D30.
3, Q11 or Q3, Q12 or Q3, Q13
Are turned on, the energy of the vehicle-mounted power supply + B is supplied to the solenoids 11, 12, and 13 of the injector.

The injector drive circuit 1 receives injection signals TQ1, TQ3, and TQ5 from the ECU 2. Each of the injection signal input terminals 1e, 1f, 1g is connected to an AND gate 3
Each transistor Q11, Q1
2 and Q13. Further, each of the injection signal input terminals 1e, 1f, 1g is connected to a discharge control circuit 22 and a constant current control circuit 23 via an OR gate 40. Discharge control circuit 22 and constant current control circuit 23
Turns on / off the transistors Q2 and Q3 by the injection signal TQ135 from the OR gate 40.

On the other hand, transistors Q11, Q12, Q1
3 is grounded via a current detection resistor R10, and the solenoid 1 of each injector is connected by the current detection resistor R10.
The currents flowing through 1, 12, and 13 are detected, and the detection results (injector current monitor signals) are output to the discharge control circuit 22, the constant current control circuit 23, and the injector overcurrent detection circuit 24.
It is taken in. The injector overcurrent detection circuit 24 includes a comparator 24a, a delay circuit 24b, and a flip-flop 2.
4c. The comparator 24a includes solenoids 11, 12,
A voltage (monitor signal) corresponding to the value of the current flowing through 13 is compared with a predetermined voltage value. When the solenoid energizing current exceeds a predetermined value, an H-level signal is sent to delay circuit 24b.
The delay circuit 24b outputs a signal to the flip-flop 24c if the state continues for a predetermined time Td after the signal from the comparator 24a rises. When noise is input by the delay circuit 24b, that is, when a signal that has been at the H level for a time shorter than Td is input, no signal is output to the flip-flop 24c. The set terminal of the flip-flop 24c is connected to the delay circuit 24b.
And the output terminal (Q terminal) is connected to each AND gate 3
1, 32, and 33. Flip-flop 2
4c is inverted and AND gates 31, 32,
33 is input.

The constant current control circuit 23 controls ON / OFF of the transistor Q3 according to the current flowing through the solenoids 11, 12, 13 of each injector. As a result, the solenoids 11, 12, and
13 is supplied with a constant current. The diode D20 is a feedback diode for controlling a constant current, and the current flowing through each of the solenoids 11, 12, and 13 when the transistor Q3 is turned off is returned via the diode D20. Also,
In the discharge control circuit 22, when the current flowing through the solenoids 11, 12, and 13 of each injector exceeds a predetermined value, the transistor Q2 is forcibly turned off.

Also, the solenoids 11 of each injector,
The terminals 12, 13 (terminals 1b, 1c, 1d) are connected to the capacitor C1 via the energy recovery diodes D11, D12, D13, and flyback energy (back electromotive force) generated when the power supply to the solenoids 11, 12, 13 is cut off. Power energy) of the diodes D11, D12, D13
And is returned to the condenser C1 and collected. That is,
The capacitor C1 is charged by using the flyback energy of the solenoids 11, 12, and 13, and the solenoid 1 is charged.
By effectively utilizing the currents flowing through 1, 12, and 13, the load on the charging voltage control circuit 20 can be reduced, and heat generation can be suppressed.

The operation according to the above configuration will be described with reference to the time chart of FIG. 2, the injection signals TQ1, TQ3, TQ5, the output signal TQ135 of the OR gate 40, the input state of the reset terminal of the flip-flop 24c, the output of the comparator 24a, the delay circuit 2
4b (set signal of flip-flop 24c),
Output of flip-flop 24c, state of common terminal 1a, signals TWV1, TWV3, TWV5 to the gates of transistors Q11, Q12, Q13, output signal of charging overvoltage detection circuit 21, injector current, capacitor C1
3 shows the charging voltage.

The power supply voltage is boosted by the charging voltage control circuit 20 in FIG. 1 and the like, and energy higher than the onboard power supply + B is stored in the charging capacitor C1. Specifically, the charging voltage is controlled to about 130 volts by the operation of the charging voltage control circuit 20. The charge overvoltage detection circuit 21 monitors the charge voltage. If the charge voltage becomes 150 volts or more due to some abnormality, the charge overvoltage detection circuit 21 determines that the charge circuit is abnormal and sends a charge overvoltage detection signal to the charge voltage control circuit 20. Is output to stop the charging operation.

On the other hand, the injection signal (transistor ON signal) TQ1 (TQ3, TQ3)
Q5) is output. This signal TQ1 (TQ3, TQ
5) is sent to the discharge control circuit 22 and the constant current control circuit 23 via the OR gate 40, and the transistors Q2 and Q3 are turned on. At the same time, the signal TQ1 (TQ3, TQ5) is applied to the transistor Q via the AND gate 31 (32, 33).
11 (Q12, Q13) and the transistor Q11
(Q12, Q13) is turned on. At this time, the discharge control circuit 22 generates the peak current Ip in FIG. That is, the transistors Q2, Q11 (Q12, Q13) are turned on by the input ON signal TQ1 (TQ3, TQ5), and the energy stored in the capacitor C1 is supplied to the solenoid 11 (12, 13) of the injector, and the peak current Ip Cause. Subsequently, as shown in FIG. 2, the two-stage constant currents I1, I
Generates 2. That is, the input ON signal TQ1 (T
Q3, TQ5), the transistors Q3, Q11 (Q
12, Q13) is turned on to supply the energy of the vehicle-mounted power supply + B to the solenoid 11 (12, 13).

At the moment indicated by t1 (t2) in FIG. 2, the moment the injection signal TQ1 (TQ3, TQ5) is turned off from the on state, the solenoid 11 of the injector is turned off.
The flyback energy generated by cutting the current of (12, 13) is supplied to the charging capacitor C1 by the energy recovery diode D11 (D12, D13).
Will be collected. Thereby, the charging voltage increases.

In the comparator 24a of the injector overcurrent detection circuit 24 shown in FIG. 1, when the value of the current flowing through the solenoid 11 (12, 13) of the injector becomes larger than a predetermined value, an H level signal is output and the delay circuit 24b
When the H level state continues for a predetermined time, a signal (overcurrent detection signal) is sent to the set terminal of the flip-flop 24c. Then, a latched overcurrent detection signal is output from the output terminal (Q terminal) of the flip-flop 24c, and this signal is input to one input terminal of the AND gate 31 (32, 33) in an inverted state. As a result, the output of the AND gate 31 (32, 33) is
Signal LQ goes low despite the signal TQ1 (TQ3, TQ5) being output from the transistor Q11 (Q5).
12, Q13) is interrupted (prohibited).

As described above, the current detecting resistor R10 and the injector overcurrent detecting circuit 24 as the second inhibiting means are provided.
By detecting the current value flowing through the solenoid 11 (12, 13), when the current value exceeds a predetermined value, an overcurrent detection signal is output and the solenoid 11 (12, 13) based on the current ON signal TQ1 (TQ3, TQ5). ) Is terminated halfway. The flip-flop 24c of the injector overcurrent detection circuit 24 receives the overcurrent detection signal as a set signal and outputs the set signal to the solenoid 11 (12, 13).
It functions as a memory holding unit that outputs a command signal for terminating energization of the power supply. This flip-flop 24c
Are injection signals TQ1, TQ3 through the OR gate 40.
It is reset based on TQ5 (TQ135).

Third and fifth fuel injectors other than the injector for the first cylinder
The same operation is performed for the cylinder injector. Here, when a power short-circuit occurs at the common terminal 1a in FIG. 1 at the timing of t3 in FIG. 2 (when a power short-circuit occurs in the energy supply lines to the solenoids 11, 12, and 13 of the injectors),
A large current flows through 12 and 13. Then, the current becomes larger than the overcurrent threshold in the overcurrent detection circuit 24 (at timing t4 in FIG. 2), and the energization of the solenoids 11, 12, and 13 by the current ON signal (load drive signal) is terminated in the middle. (Timing t5 in FIG. 2). The flyback energy generated at this time is supplied to the capacitor C1 by the energy recovery diodes D11, D12, and D13.
And the charging voltage at the capacitor C1 rises. Therefore, an overcharge state occurs, and the charge voltage becomes larger than the threshold value (150 volts) at the timing of t6 in FIG.
The charging operation of the capacitor C1 is stopped by the charging overvoltage detection circuit 21. However, the flyback energy is returned to the capacitor C1 by the energy recovery diodes D11, D12, and D13, so that the charging voltage at the capacitor C1 tends to keep increasing.

In this embodiment, a gate (logic) 50 for inverting the charge overvoltage detection signal and for ANDing the signal TQ135 is added to the input side of the reset terminal of the preceding flip-flop 24c of the injector overcurrent detection output of FIG. The ON signal T is output by the AND gate 50.
Q135 is input and a signal obtained by inverting the overvoltage detection signal is input, and its logical product is output as a reset signal for the flip-flop (memory holding means) 24c. Thus, even if the injector is in the overcurrent state in the overcharge state, the injection signals TQ1, TQ3, TQ5
Does not reset the flip-flop 24c and turns on the transistors Q11, Q12 and Q13.
1, TWV3 and TWV5 do not appear.

That is, the overvoltage detection signal is output from the charging overvoltage detection circuit 21 and the flip-flop 24
When c is set and the overcurrent detection signal is output, the flip-flop 24c is reset by the AND gate 50 as the third prohibiting means even when the injection signals (transistor ON signals) TQ1, TQ3, and TQ5 are input. Instead, the power supply to the solenoids 11, 12, and 13 of each injector is stopped. Thus, the solenoid 1
When a power short circuit or the like occurs in the energy supply lines to the energy supply lines 1, 12, and 13, the overvoltage detection signal is output and the overcurrent detection signal is output.
The operations 12 and 13 themselves are stopped. As a result, it is possible to prevent the charging voltage at the capacitor C1 from increasing due to the energy recovery diodes D11, D12, and D13.

Further, the charging stop operation and the operation when the power supply is short-circuited will be described. If overcharging occurs when no injector overcurrent occurs, the charging overvoltage detection circuit 21 stops the charging operation. At that time, the transistors Q11 and Q11
12 and signals TWV1, TWV3, TW for turning on Q13
V5 is discharged quickly by the solenoids 11, 12, and 13 without cutting. However, when an overcurrent flows through the solenoids 11, 12, and 13 due to a power short-circuit or the like, the flyback energy at the time of injector overcurrent cut is larger than the energy discharged at the time of injector discharge (ΔV2> ΔV1 in FIG. 4). If the injector driving is continued, the charging voltage rises indefinitely. At the same time, the charging operation is stopped, and at the same time, the signals TWV1, T for turning on the transistors Q11, Q12, Q13 by not resetting the injector overcurrent output flip-flop 24c.
WV3 and TWV5 are cut, and injector driving is stopped.

As a result, as shown in FIG. 2, the overvoltage detection threshold value + α can be suppressed at the maximum, specifically, to about 170 volts or less. Therefore, it is possible to prevent a problem that the element is destroyed due to abnormal overcharging when the power supply is short-circuited in the fuel injection device of the diesel engine.

Further, in the state where the power supply is short-circuited, the charge in the capacitor C1 gradually decreases due to leakage after t6 in FIG.
Volts) or less, the output of the charge overvoltage detection signal from the charge overvoltage detection circuit 21 is stopped. As a result, one of the input signals of the AND gate 50 of FIG. 1 becomes H level, and the injection signals TQ1, TQ3, TQ5 are changed to the OR gate 40.
, The output of the AND gate 50 becomes H level, and the flip-flop 24
c is reset. Thereby, the flip-flop 2
4c becomes L level and AND gates 31, 3
When the injection signals TQ1, TQ3, TQ5 are input to the transistors Q2, 33, the transistors Q11, Q12, Q
13 turns on.

When the power supply short circuit occurs in the drive circuit 1 for one bank, the injectors for the first, third, and fifth cylinders are stopped by the drive circuit, but the power supply short circuit does not occur. The limp home operation is performed using the drive circuit for the other bank (for the injectors for the second, fourth, and sixth cylinders).

In the above description, the present invention is applied to the control system of the injector of the diesel engine, but may be applied to the control system of the injector of the gasoline engine.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing an injector control device according to an embodiment.

FIG. 2 is a time chart for explaining operation in the embodiment.

FIG. 3 is an electric circuit diagram showing an injector control device for explaining a conventional technique.

FIG. 4 is a time chart for explaining a conventional technique.

[Explanation of symbols]

1. Injector drive circuit 2. ECU, 11, 12,
13: injector solenoid, 20: charge voltage control circuit, 21: charge overvoltage detection circuit, 22: discharge control circuit, 23: constant current control circuit, 24: injector overcurrent detection circuit, 24a: comparator, 24b: delay circuit , 2
4c: flip-flop, 31, 32, 33: AND gate, 40: OR gate, 50: AND gate, + B:
In-vehicle power supply, C1 ... capacitor, D11, D12, D13
... Energy recovery diode, Q1, Q2, Q3, Q1
1, Q12, Q13: transistors, R1, R10: resistors.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AA07 AB02 AC09 BA28 CC06 CE22 CE29 CE30 DC26 3G301 HA02 JB00 JB08 LB11 LC10 NA07 NA08 PE01 PE08 PF03 PG00

Claims (4)

[Claims] 1. An electromagnetic load (11, 12, 13), a capacitor (C1) connected to the electromagnetic load and storing energy to be supplied to the electromagnetic load, and a charging unit for performing a charging operation of the capacitor (1). L1, Q
1, 20, R1, D1), a switching element (Q2, Q11, Q12, Q13) for supplying energy stored in the capacitor to the electromagnetic load in response to an input ON signal, and energizing the electromagnetic load. An energy recovery diode (D11, D12, D13) for returning flyback energy generated at the time of cutoff to the capacitor; and detecting a charging voltage at the capacitor and outputting an overvoltage detection signal when the charging voltage exceeds a predetermined value. First inhibiting means (21) for stopping a charging operation of the capacitor by the charging means, detecting a current value flowing through the electromagnetic load and outputting an overcurrent detection signal when the current value exceeds a predetermined value. Second prohibiting means (R10, 24) for terminating energization of the electromagnetic load by the ON signal in the middle, and the overvoltage detection signal When the overcurrent detection signal is outputted is outputted, a third inhibiting means for stopping the energization Entering the ON signal in the electromagnetic load (50)
And a control device for an electromagnetic load. 2. An electromagnetic load connected to an on-vehicle power supply.
12, 13), a first switching element (Q3, Q11, Q12, Q13) for supplying energy of the vehicle-mounted power supply to the electromagnetic load according to an input ON signal; A capacitor (C1) in which higher energy is stored than in-vehicle power, and charging means (L1, Q1) for charging the capacitor.
, 20, R1, D1), a second switching element (Q2, Q11, Q12, Q13) for supplying energy stored in the capacitor to the electromagnetic load in response to an input ON signal; An energy recovery diode (D11, D12, D13) for returning flyback energy generated when the power supply to the capacitor is cut off to the capacitor; and an overvoltage detection signal when the charging voltage of the capacitor is detected and the charging voltage exceeds a predetermined value. And a first prohibiting means (21) for stopping the charging operation of the capacitor by the charging means, detecting a current value flowing through the electromagnetic load and outputting an overcurrent detection signal when the current value exceeds a predetermined value. A second prohibiting means (R10, 24) for terminating the energization of the electromagnetic load by the on signal at this time in the middle; When the overcurrent detection signal with the signal is outputted is outputted, a third inhibiting means also receiving the ON signal to stop energization of the electromagnetic load (50)
And a control device for an electromagnetic load. 3. The electromagnetic load control device according to claim 1, wherein the second prohibiting means (R10, 24) inputs an overcurrent detection signal as a set signal and supplies power to the electromagnetic load. And a memory holding means (24c) for outputting a command signal for terminating the overvoltage detection signal as an input of an ON signal and a signal obtained by inverting an overvoltage detection signal. And an AND gate (50) that outputs the reset signal as a reset signal of the memory holding means. 4. The electromagnetic load control device according to claim 1, wherein the electromagnetic load is a solenoid of an injector that supplies fuel to an engine. .