DE10200847A1 - Fault detection circuit of a fuel injector - Google Patents

Abstract

The present invention provides a failure detection circuit of a simple fuel injector for detecting an abnormality of each phase or an abnormality of an inter-phase short in a driver circuit of an electromagnetic fuel injection valve with respect to each cylinder of a multi-cylinder engine, and enables a rescue operation. The fault detection circuit of the fuel injection device is equipped with common ON / OFF elements for feeding electromagnetic valve driver coils (5, 8 and 6, 7), which are contained in groups with intervals of a fuel injection sequence, and separate ON / OFF elements (13, 14, 23 and 24) corresponding to each of the electromagnetic coils (5, 6, 7 and 8) and turn-off rise detection circuits (35 and 36) for implementing an OR gate connection of a turn-off rise signal (Vs) received at the time of the interruption of a Current flow of the electromagnetic coil is generated in different groups. An output of a drive signal pulse with respect to any of the electromagnetic coils (5, 6, 7 and 8) is stopped based on an error judgment or a duplication judgment of a turn-off rise signal corresponding to a pulse group of a drive signal generated by a microprocessor (9), wherein the common ON / OFF element (11 or 21) is interrupted.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a Fault detection circuit one Fuel injector regarding one Multi-cylinder engine in a vehicle and the like and in particular an error detection circuit Fuel injection device for detecting a Interruption or short circuit of one electromagnetic coil for driving a electromagnetic fuel injector, the Interruption or short circuit of a driver element electromagnetic coil, the interruption or the Short circuit of a wiring line of the electromagnetic Coil or the like to report misconduct and display to perform a rescue operation.

2. Description of the prior art

Both a steep overexcitation control and one Maintenance control through low current usually to control the electromagnetic coil used to drive the electromagnetic Fuel injector, which causes the response of the electromagnetic valve is improved and the Temperature rise of the electromagnetic valve suppressed becomes. In the usual procedure, interrupt or Short circuit problems of the electromagnetic coil, the Wiring line, an ON / OFF element and the like captured by monitoring voltage or current each Section of the driver circuits of the electromagnetic Kitchen sink. There is also a well-known concept for Simplify a signaling process by implementing OR gate of an error detection signal in Regarding multichannel load.

Japanese Patent Application Laid-Open No. Hei 10-257799 "output idle detection device one Multi-channel output device "discloses such a concept that a load circuit is interrupted by supplying Microcurrent to the load during the time the load is not is driven like one in terms of multi-channel load Excitation coil of a stepper motor, the voltage on both End of load increases and an interruption is caused recorded this increase. Although there is no reference to one Detect a short circuit of a load in it Publication there, it shows such a concept that an interrupt detection signal is supplied to one usual comparison judgment circuit by a Diode-OR circuit.

In contrast, according to the Japanese patent application with the disclosure number Sho 62-290111 "Fault detection circuit of a Fuel injector driver circuit for. an internal one Internal combustion engine ", such a concept demonstrated that a Group detection of the open or short circuit problem the electromagnetic coil, the wiring line, the ON / OFF element or similar is implemented by Detect an off-rise voltage that occurs Current interruption time electromagnetic fuel injector driver coil.

In addition, in the Japanese patent application with the Publication number Hei 9-112735 "Solenoid valve driver device" for example in Regarding the driving of an electromagnetic coil of the Fuel injection solenoid valve of such a concept shown that a steep driver charging circuit and a Low-maintenance circuitry can be provided and the break, short circuit or the like Variety of electromagnetic coils and the Wiring line is detected by monitoring the charged voltage and discharged voltage of a Capacitor in the charging circuit.

Another concept shown in this example is specifically described that a variety of electromagnetic fuel injector driver coils is divided into several groups and the rescue service running smoothly based on a Error detection result.

Still further is according to the Japanese patent application with the Hei 10-318025 "control device for fuel injector "an ON / OFF control concept shown such that one end of a plurality of Injection coils that have an interval of Fuel injection sequences in two or multi-line degrees or Have keying and without overlapping the current flow clocking are connected to a common driver output circuit and the other ends of the injection coils are one Device connected for changing ON / OFF separately during a current flow cycle of each injection coil.

Japanese Patent Application No. Hei 12-380652 "Deviation detection device of an electrical Load driver system in a vehicle "describes one Procedure that a deviation detection signal with a OR gate combination, separately in a microprocessor is recorded. This concept is presented in the present Invention used.

In the conventional techniques described above are different types of deviation detection methods taught that the interruption or short circuit of the electrical load of the electromagnetic coil or similar, the interruption or short circuit of the ON- / OFF control of the electromagnetic coil, the Open circuit or short circuit of the wiring line of the electromagnetic coil.

However, each of the conventional techniques has a problem so that a fault detection circuit for systematic Detect abnormality related to various types assumed abnormalities including one Interphase short circuit of high electrical load and a mass is not taken into account.

SUMMARY OF THE INVENTION

The present invention has been accomplished to accomplish the above solve the problem described and a procedure s provide that includes a countermeasure in addition for error detection and in particular it is a goal of present invention, an error detection circuit of a simply constructed fuel injector to be provided for detecting a deviation of each phase or an abnormality of interphase short in a driver circuit of an electromagnetic Fuel injector with respect to each cylinder one Multi-cylinder engine and running a rescue operation.

The error detection circuit of the Fuel injection device according to the present Invention comprising: a variety of electromagnetic Coils for driving an electromagnetic Fuel injector with respect to each cylinder one Multi-cylinder engine; a microprocessor to generate one Pulse group of a driver signal and a steep one Over-excitation control signal; a variety of separate ON- / OFF elements for driving the electromagnetic coils by sequentially executing ON / OFF operation corresponding to the pulse group of a driver signal which is from the microprocessor is generated; a variety of groups common ON / OFF elements for driving one Group feeding in electromagnetic coils in the group, which is formed from at least a variety of electromagnetic coils with the interval of Fuel injection sequence in a two or multi-line Degrees, corresponding to the steep overexcitation control signal that is generated by the microprocessor; and a variety of Power off rise detection circuits for detecting a Cutoff rise voltage by opening the circuit of the separated ON / OFF element is induced, which in involved at least one difference group electromagnetic coil corresponds to the processor Compares detection signals from the variety of Switch-off rise detection circuits are detected at Judge an abnormality based on whether an error of the detection signal and a duplication of the Detection signal are included.

Each of the turn-off rise detection circuits detects the Switch-off rise voltage by detecting a higher one Voltage value at both ends of the separate ON / OFF Elementes as a voltage source when the circuit this separate ON / OFF element is opened.

Each of the turn-off rise detection circuits detects the Switch-off rise voltage by detecting a higher one Voltage of a negative side connection of the electromagnetic coil than that of a supply connection, which is connected to the common ON / OFF element, if the circuit of the separate ON / OFF element and the Circuit of this common ON / OFF element opened become.

The common ON / OFF element contains an OR circuit to implement an OR operation of Detection signals by the respective OFF rise detection circuits with respect to the in electromagnetic group contained in a different group Coil are output and the microprocessor one Abnormality judged based on an output of the OR circuit.

The common ON / OFF element becomes the steep one Overexcitation control signal operated by the Microprocessor is generated and one Low current hold control signal for obtaining this operation of the electromagnetic coil.

An overexcitation booster circuit to raise one Power supply voltage is set up. The common ON / OFF element consists of one high-voltage side ON / OFF element for driving the Feeding into the electromagnetic coil through the Overexcitation booster circuit and out of one low-voltage ON / OFF element for driving the Feeding into the electromagnetic coil according to the Low current hold control signal for maintaining the operation of the electromagnetic coil.

The high-voltage ON / OFF elements divide the Overexcitation booster circuit and the overexcitation Booster circuitry is shared in terms of all electromagnetic coils.

In the case where the microprocessor has an abnormality judged based on the detection signal from the Shutdown rise detection circuit is detected is a Device for interrupting a group current flow provided to interrupt the corresponding common ON / OFF element and the separate ON / OFF element that is connected in series with the common ON / OFF element, and the electromagnetic coil that is in one of those interrupted group containing ON / OFF element different group is included, leads one Rescue operation off.

If the microprocessor detects an abnormality based on a Failure of the cut-off rise voltage is assessed in the case in which there is a duplication of the current flow period electromagnetic coil in tandem there is one Shortening treatment of a current flow period of the Pulse group of driver signals executed.

A device for reporting an abnormality upon receipt an abnormality signal is provided and when the Microprocessor judges an abnormality based on the Detection signal from that OFF rise detection circuit has been detected the abnormality signal is output to this device to report the abnormality.

The microprocessor is equipped with a Connection interface circuit with an external tool.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

Fig. 1 is a detailed electrical circuit diagram of a fault detection circuit of a fuel injector according to the embodiment 1 of the present invention;

FIG. 2 shows a partial detailed illustration of a fault detection circuit of a fuel injection device according to exemplary embodiment 1 of the present invention;

Fig. 3 is a sketch of a cylinder of an error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 4 is a time chart for explaining a normal operation of an error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 5 is a schematic block diagram of a phase deviation in the error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 6 is a time chart for explaining the occurrence of an abnormality in the ground fault detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 7 is a schematic block diagram for explaining the occurrence of a Zwischenphasenkurzschlussabnormalität in the error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 8 is a timing chart for explaining the occurrence of an in-group intermediate phase short circuit in the error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

Fig. 9 is a time chart for explaining the occurrence of a group interphase short circuit in the error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

FIG. 10 is a flowchart of the error operation of the error detection circuit of a fuel injector according to the embodiment 1 of the present invention;

FIG. 11 is a detailed electrical circuit diagram of a fault detection circuit of a fuel injector according to the embodiment 2 of the present invention; and

Fig. 12 is a detailed electrical circuit diagram of a fault detection circuit of a fuel injector according to the embodiment 3 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

Fig. 1 is a detailed electrical circuit diagram of a fault detection circuit of a fuel injector according to the embodiment 1 of the present invention. The structure of this circuit is described below.

In Fig. 1, a fuel injection control device mainly consists of a microprocessor 9 , a first driver circuit 10 , a second driver circuit 20 and the like as described below. A power supply switch 2 connects a voltage source 3 such. B. a battery of a vehicle with the fuel injection control device 1 .

A sensor group 4 for deciding the timing of a fuel injection, a fuel quantity (fuel period) and the like consists of a crank angle sensor, a cam angle sensor, a throttle position sensor and the like. An input signal from the sensor group 4 is fed to the microprocessor 9 .

The first driver control circuit 10 and the second driver control circuit 20 control and drive a first electromagnetic coil 5 , a second electromagnetic coil 6 , a third electromagnetic coil 7 and a fourth electromagnetic coil 8 . The electromagnetic coils 5-8 perform ON / OFF control of a fuel injection valve with which each cylinder of an engine shown in FIG. 3 and described below is equipped.

The structural elements of the first driver control circuit 10 will be described. A common ON / OFF element 11 is a transistor or the like which is connected between one end of the first electromagnetic coil 5 and one end of the fourth electromagnetic coil 8 and the voltage source 3 . A commutation diode 12 is connected between a load side of the common ON / OFF element 11 and a negative side connection of the voltage source 3 . A separate ON / OFF element 13 is connected to the other end of the first electromagnetic coil 5 and is a transistor or the like for closing a circuit in accordance with a separate drive signal SW1 output from the microprocessor. Similar to the separate ON / OFF element 13 , a separate ON / OFF element 14 is connected to the other end of the fourth electromagnetic coil 8 and is a transistor or the like for closing a circuit in accordance with a separate drive signal SW3 which is from the microprocessor 9 is output.

A current sensing resistor 15 is connected between the separate ON / OFF element 13 and the separate ON / OFF element 14 and the negative-side connection of the voltage source 3 . The separate ON / OFF elements 13 and 14 do not close the circuit at the same time. An OR gate element 16 brings the common ON / OFF element 11 into conduction in accordance with a steep overexcitation control signal SW13 output from the microprocessor 9 , and performs ON / OFF control of the common ON / OFF element 11 by an output of an AND gate element 18 , which will be described below.

An OR gate element 17 outputs the separated driver signals SW1 and SW3 as input signals to the AND gate element 18 . A low current hold control circuit 19 is an ON / OFF control circuit for supplying low current (low current for the hold operation) for maintaining the operation of the first (or the fourth) electromagnetic coil 5 (or 8 ). Accordingly, when the voltage at both ends of the current sensing resistor 15 is lower than the predetermined voltage, the low current hold control circuit 19 outputs a low current hold control signal DT13 to make the common ON / OFF element 11 conductive by the AND gate element 18 and the OR gate element 16 .

In the structural elements of the second driver control circuit 20 , 21-29 are the same as the 11-19 described above. SW4 identifies a signal equal to SW1. SW2 identifies a signal equal to SW3. INJ2 identifies an electromagnetic coil equal to INJ1. INJ3 identifies an electromagnetic coil equal to INJ4. Therefore, the description of these elements of the second driver control circuit 20 is omitted.

A diode 31 is connected to an anode at a connection point of the first electromagnetic coil 5 and the separate ON / OFF element 13 . A diode 32 is connected to an anode at a connection point of the second electromagnetic. Coil 6 and a separate ON / OFF element 23 connected. Similarly, a diode 33 is connected to an anode at a connection point of the third electromagnetic coil 7 and a separate ON / OFF element 24 , and a diode 24 is connected to an anode at a connection point of the fourth electromagnetic coil 8 and the separate ON / OFF element 24 . / OFF element 14 connected.

A switch-off rise detection circuit 35 includes a comparator circuit 35 a. Resistors 35 b and 35 c divide the voltage supplied by a cathode of diodes 31 , 33 . A switch-off rise detection circuit 36 includes a comparator circuit 36 a (not shown). Part resistors 36 b and 36 c (not shown) share the voltage supplied by a cathode of the diodes 34 , 32 .

If a partial voltage of the partial resistors 35 b and 35 c is higher than that of the voltage source 3 , the comparator circuit 35 a generates a detection signal IN13 of a logic level "L" in order to supply the signal to the microprocessor 9 . Similarly, if the partial voltage of the partial resistors 36 b and 36 c is higher than that of the voltage source 3 , the comparator circuit 36 a generates a detection signal IN42 of the logic level "L" for supplying the signal to the microprocessor 9 .

An external tool 40 (or device 40 ) writes a control program in relation to the microprocessor 9 and reads out and displays a content of the data memory (not shown). An interface circuit 41 is set up between the external tool 40 and the microprocessor 9 . An abnormality alarm / display device 42 is driven based on an abnormality signal or the like of the microprocessor 9 .

Fig. 2 is a partial detailed diagram showing a feed circuit with respect to the first electromagnetic coil 5 in Fig. 1. The structure of the feed circuit will be described below.

In FIG. 2, a low signal level resistance (pull-down resistor) is connected in parallel to the commutating diode 12 a 12. Constant voltage diodes 13 a and 14 a perform a cut-off voltage-limiting function of the separate ON / OFF elements 13 , 14 in the same way. A low current Ih for the holding operation is the current that flows into the first electromagnetic coil 5 .

When both the common ON / OFF element 11 and the separate ON / OFF element 13 open the circuit, an off-rise voltage Vs is generated. This switch-off rise voltage Vs is generated by a counter-electromotive force which generates the first electromagnetic coil 5 for holding the low current Ih for the holding operation, which has flowed so far. The output rise voltage Vs is approximately equal to the reduced voltage of the constant voltage diode 13 a.

However, this output rise voltage Vs falls sharply along with damping the low current Ih for the holding operation. The pull-down resistor 12 a determines the switch-off rise voltage Vs as Vs = 0.

If the circuit of the separated ON / OFF element 13 is closed due to the abnormality of the short circuit or the like of the separate ON / OFF element 13 and the common ON / OFF element 11 interrupts the supply, no steep interruption will occur Excitation coil executed due to the construction of a commutation circuit, which consists of the commutation diode 12 and the separate ON / OFF element 13 . Therefore, no turn-off rise voltage Vs is generated.

On the other hand, in the course of opening the circuit of the separate ON / OFF element 13 when the separate ON / OFF element 14 is brought into the conductive state to feed the fourth electromagnetic coil 8 , and the common ON / OFF OFF element 11 is activated. A supply voltage Vb of an output terminal section of the common ON / OFF element 11 is generated as an output of the diode 31 , and Vb occurs as an apparent turn-off rise voltage Vs. However, the practical output rise voltage Vs is higher than the supply voltage Vb (Vb <Vs). Therefore, the comparator circuit 35 a written above is capable of separately obtaining this voltage.

FIG. 3 is an illustration showing a cylinder of the fault detection circuit of the fuel injector shown in FIG. 1. In Fig. 3, reference numeral 50 denotes a crankshaft of an engine. Reference numerals 51 to 54 denote first to fourth cylinders, for each of which fuel injection is carried out by the electromagnetic coils 5-8 . When the separate ON / OFF element 13 and the common ON / OFF element 11 are operated to feed the first electromagnetic coil at a first time, the fuel injection to the first cylinder 51 is carried out. Next, when the separate ON / OFF member 24 and a common ON / OFF member 21 are operated to feed the third electromagnetic coil at a second time, the fuel injection to the third cylinder 53 is carried out. In addition, when the separate ON / OFF element 14 and the common ON / OFF element 11 are operated to feed the fourth electromagnetic coil 8 at a third time, the fuel injection to the fourth cylinder 54 is carried out. Still further, when the separate ON / OFF element 23 and the common ON / OFF element 21 are operated to feed the second electromagnetic coil 6 at a fourth time, the fuel injection to the second cylinder 52 is performed.

In the arrangement described above, when either the first cylinder 51 or the fourth cylinder 54 include an abnormality in the fuel injection, both cylinders 51 and 54 are stopped. Here, it is a stable countermeasure that the rescue operation is carried out only by the second cylinder 52 and the third cylinder 53 . If either the second cylinder 52 or the third cylinder 53 contains an abnormality in the fuel injection, both cylinders 52 and 53 are stopped. Here it is a stable countermeasure that the rescue operation is carried out only by the first cylinder 51 and the fourth cylinder 54 . The common ON / OFF elements 11 and 21 in Fig. 1 are arranged according to this grouping.

The separate drive signals SW1-SW4 of the microprocessor 9 in Fig. 1 are numbered according to the order of fuel injection.

Fig. 4 is a timing diagram for explaining a normal operation of the error detection circuit of the fuel injector according to the first embodiment. In Fig. 4 (a) SW13 showing an output characteristic of the steep overexcitation control signal SW13 of the microprocessor 9, (b) DT13 showing an output characteristic of the low-current latch control signal DT13, (c) SW1 showing an output characteristic of the separate driving signal SW1 of the microprocessor 9, (d) SW3 shows an output characteristic of the separate driver signal SW3 of the microprocessor 9 , (e) SW42 shows an output characteristic of a steep overexcitation control signal SW42 of the microprocessor 9 , (f) DT42 shows an output characteristic of a low current hold control signal DT42, (g) SW4 shows an output characteristic of the separate driver signal SW4 of the microprocessor 9 , and (h) SW2 shows an output characteristic of the separated drive signal SW2 of the microprocessor 9 .

The separated drive or driver signals SW1-SW4 carry one output at a time. The steep one Overexcitation control signal SW13 generates an Short-term output signal in accordance with a Output clocking of the separate driver signals SW1 and SW3. On similarly that generates steep Overexcitation control signal SW42 a short-term output signal in Agreement with an output clock of the separated Driver signals SW4 and SW2.

In Fig. 4, (i) INJ1 shows a current waveform of the first electromagnetic coil 5 and is obtained by assembling (a) SW13, (b) DT13 and (c) SW1. Similarly, in FIG. 4 (j) INJ4 shows a current waveform of the fourth electromagnetic coil 8 and is obtained by assembling (a) SW13, (b) DT13 and (d) SW13, in FIG. 4 (k) INJ2 shows one Current waveform of the second electromagnetic coil 6 and is obtained by assembling (e) SW42, (f) DT42 and (g) SW4 and shows in FIG. 4 (1) INJ3 a current waveform of the third electromagnetic coil 7 and is obtained by assembling ( e) SW12, (f) DT42 and (h) SW2.

In FIG. 4 (m) D31 shows an output waveform of the diode 31. When the current in the first electromagnetic coil 5 is interrupted in (i) INJ1, that is, when the output of the separate drive signal SW1 in (c) SW1 is stopped (logic level "L"), the start-up voltage Vs is generated and when When current flows into the fourth electromagnetic coil 8 , the waveform of the supply voltage Vb is generated based on the ON / OFF operation of the common ON / OFF element 11 .

Similarly, 4 (n) D34 shown in Fig. An output waveform of the diode 34, (o) D32 shows an output waveform of the diode 32, and (p) D33 shows an output waveform of the diode 33.

In Fig. 4, (q) IN13 shows a waveform of the detected signal IN13. In (q) IN13, when the diode 31 or the diode 33 outputs the turn-off rise voltage Vs, the logic level becomes "L". Similarly, in Fig. 4 (r) IN42 shows a waveform of the detected signal IN42. In (q) IN13, when the diode 34 or the diode 32 outputs the output rising voltage Vs, the logic level becomes "L".

The failure detection of the fuel injection control device in the first embodiment performed by the failure detection circuit will be specifically described. Fig. 5 is a schematic block diagram showing an abnormality or deviation in the phases. A ground 60 shows a state that connects the negative-side connection of the first electromagnetic coil 5 to the negative-side connection of the voltage source 3 . If such a mass is arranged, the current flowing through the electromagnetic coil 5 is not interrupted steeply or abruptly. Therefore, the turn-off rise voltage Vs is not generated.

This phenomenon is similar to the case where the short circuit of the separate ON / OFF element 13 includes an abnormality. Even if the common ON / OFF element 11 interrupts the supply, the excitation current circulates through the commutation diode 12 and the ground circuit 60 or the separate ON / OFF element includes a short circuit. Therefore, the turn-off rise voltage Vs is not generated.

A load short circuit 61 shows a state in which a short circuit occurs between the positive and negative connection of the fourth electromagnetic coil 8 . When the load short circuit 61 occurs, no excitation current flows through the electromagnetic coil 8 . Therefore, when the circuit of the separate ON / OFF element 12 is open, no turn-off rise voltage Vs is generated.

While a load circuit short circuit occurs, the separated ON / OFF elements 13 , 14 , 23 and 24 and the common ON / OFF element 11 , 21 are protected for a short period of time by an overcurrent protection function contained in these elements. The elements described above are protected so as not to blow due to the extinction of the driver instruction signal from the microprocessor 9 .

Reference numerals 62 to 64 show interrupt circuits. If there is an interruption in the wiring line, an interruption in the coil, an ON / OFF error of the ON / OFF element or the like, no excitation current flows into the electromagnetic coils 6 , 7 . Therefore, when the circuit of the separate ON / OFF elements 23 , 24 is opened, the OFF rise voltage Vs is not generated.

FIG. 6 is a time chart for explaining an operation in the case where the mass has an abnormality in FIG. 5. Here, the difference from the time chart of normal operation shown in FIG. 4 is mainly described.

In Fig. 6, a different current waveform 65 in (i) INJ1 shows a current waveform in which no low-current driver control is performed for the hold operation because the exciting current in the first electromagnetic coil 5 does not flow into the current sensing resistor 15 (see Fig. 1) due to the mass 60 . A duplication current waveform 66 is a current approximately equal to the fourth electromagnetic coil 8 of (j) INJ4 in Fig. 6, and shows the state that the normally non-flowing current flows into the first electromagnetic coil 5 with a ground because the common ON / OFF OFF element 11 is operated.

In FIG. 6, an error rise voltage 67 in (m) D31 shows that the switch-off rise voltage Vs, which is normally generated, is not generated because the excitation current of the first electromagnetic coil 5 is not interrupted steeply due to the mass 60 . In FIG. 6, 68 shows an error signal (q) IN13 the condition that there is no detection signal, that is normally generated due to the increase in error voltage 67th

As described above, when the turn-off rise voltage Vs includes the error that occurs due to various abnormalities in the phases and the error is detected, the common ON / OFF element of the error phase or all the separated ON / OFF elements associated with the common ON / OFF element are connected in series, interrupted as described below in Fig. 10. The fuel injection as a rescue operation is carried out by the electromagnetic coils in the uninterrupted group.

However, if the errors of the output rise voltage Vs in occur in all groups, all ON / OFF elements interrupted and the engine cannot be operated.

Fig. 7 is a schematic block diagram regarding an inter-phase deviation in the phases. In FIG. 7, an intermediate phase short circuit 70 shows the state that a short circuit occurs between the negative-side connections of the first electromagnetic coil and the fourth electromagnetic coil 8 . An interphase short circuit 71 shows the state that a short circuit occurs between the negative-side connection of the second electromagnetic coil 6 and the fourth electromagnetic coil 8 . The interphase short circuit 70 is an in-group interphase short circuit that occurs between electromagnetic coils that are driven by the same common ON / OFF element 11 . The inter-phase short circuit 71 is an over-group inter-phase short circuit that occurs between the electromagnetic coils that are driven by different common ON / OFF elements.

Fig. 8 is a timing chart for explaining an operation at the time of deviation or the abnormality of the interphase short-circuiting, which is included within the group shown as in Fig. 7. The difference from the normal operation timing chart shown in Fig. 4 will mainly be described. A deviation current waveform 72 of (i) INJ1 in Fig. 8 and a deviation current waveform 77 of (j) INJ4 in Fig. 8 show the state that the low current for the holding operation Ih is reduced to half, resulting from that the first The electromagnetic coil 5 and the fourth electromagnetic coil 8 are connected in parallel by the interphase short circuit 70 .

A duplication current waveform 73 of (i) INJ1 in Fig. 8 and a duplication current waveform 74 of (j) INJ4 in Fig. 8 show waveforms of the additional duplication current which does not normally flow and which results from the first electromagnetic coil 5 and the fourth electromagnetic Coil 8 are connected in parallel by the in-phase short circuit 70 .

A duplicate rise voltage 76 of (m) D31 in FIG. 8 and a duplicate rise voltage 77 of (n) D34 in FIG. 8 show the turn-off rise voltage Vs along with the interruption of the duplication waveforms 73 , 74 . A duplication signal 78 of (q) IN13 in Figure and a duplication signal 79 of (r) IN42 in Fig. 8 shows the duplication detection signal along with the duplication rise voltages 76 , 77 .

FIG. 9 is a timing chart for explaining an operation at a time of abnormality of an interphase short circuit included in the group shown in FIG. 7. Mainly, the difference from the normal operation timing chart shown in Fig. 4 will be described.

If all of the separate ON / OFF elements 13 , 14 , 23 and 24 are not brought into conduction with each other at the same time (ie, the fuel injection period is relatively short), each of the electromagnetic coils S through 8 is controlled and guided normally the operation from the timing diagram shown in Fig. 4. However, each of the electromagnetic coils 5 to 8 is in the state that the abnormality of the interphase short cannot be detected instead of being controlled normally. In contrast, the time chart of Fig. 9 shows the case where the period for fuel injection is long and the adjacent electromagnetic coils are simultaneously brought into conduction.

A damping current waveform 80 of (j) INJ4 in FIG. 9 shows the state that the circuit of the separate ON / OFF element 14 or the circuit of the common ON / OFF element 11 is open and the low current for the holding operation Ih, that flows through the fourth electromagnetic coil 8 is damped by the commutation diode 12 , the interphase short-circuit 71 and the separate ON / OFF element 23 . An error rise voltage 81 of (n) D34 in FIG. 9 shows the state that the turn-off rise voltage Vs that is normally generated is not generated such that the fourth electromagnetic coil 8 is not interrupted steeply. Similarly, an error signal 82 from (r) IN42 in FIG. 9 shows the state that the detection signal that is normally generated is not generated under the influence of the error rising voltage 81 .

There are four types of abnormalities in the interphase shorting across groups with respect to the negative side wiring line of the electromagnetic coil. In any case, the failure of the cut-off rise voltage Vs occurs on the side of the conductive operating state of the electromagnetic valve in the temporary tandem operation. In this case, if the common ON / OFF element that drives the electromagnetic coil on the conducting side or the separate ON / OFF element is interrupted, the same countermeasures can be taken as those in the case of the phase deviation, which is shown in FIG . Since the countermeasure can be standardized, this is pleasant.

If the period of fuel injection at this Inter-phase short is shortened across groups, to duplicate the period for injecting Avoiding fuel, however, is not necessary for the common ON / OFF element or the separate ON / OFF Element to be interrupted. Furthermore, that common ON / OFF element or the separate ON / OFF Element of the page of the following operations are interrupted even if the common ON / OFF element or the separate ON / OFF element is interrupted.

The overall operation of the fault detection circuit of the fuel injection device according to the first embodiment as described above will now be described with reference to FIG. 10, which is a flowchart showing an operation of the microprocessor 9 .

In Fig. 10, operation starts at step 100 . At step 101 , which follows step 100 , the microprocessor 9 checks whether a reset command has been transmitted by the external tool 40 . If the test step 101 returns YES, the microprocessor 9 resets the error information stored in the RAM in step 102 . If the operation of step 102 is completed, or if step 101 is NO, if the external tool 40 is not connected to the microprocessor 9 or if the external tool 40 has not sent any reset information despite being connected to the microprocessor 9 , the microprocessor 9 checks Step 105 whether it is currently generating separate driver signals SW1-SW4.

If step 105 returns NO if the fuel injection is not being performed, the microprocessor 9 goes to step 106 and returns to the start step 100 .

If step 105 is YES, the microprocessor 9 updates the most recent situation of the separate drive signals SW1-SW4 by performing the repetitive operation and maintains the situation. At step 108 , which follows step 107 , the microprocessor 9 updates the last input situation of the detection signals IN13 and TN42 and maintains the situation. At step 110 following step 108, the microprocessor 9 checks whether there is an error in the detection signals IN13 and IN42 just after the falling edge (change time of the logic from "H" to "L") of the separate driver signals SW1-SW4. If the test step 110 returns "YES", the microprocessor 9 checks in step 111 whether there is a duplication of the current flow period of the electromagnetic coil which is temporarily operated in tandem in the pulse group of the driver signals updated and maintained in step 105 . If the test step 111 returns YES, the microprocessor 9 stores this situation at step 112 to shorten the current flow period and issue an alarm / display regarding the abnormality of the alarm / display device 42 . The microprocessor 9 keeps the stored information until the information is reset in step 102 .

If step 111 returns NO, the microprocessor 9 determines in step 113 which phase of the electromagnetic coil includes an off-rise voltage error Vs in accordance with which separated drive signal corresponds to the off-rise voltage error Vs and stores the determination. In step 114 following step 113 , the microprocessor 9 interrupts the common ON / OFF element which drives the electromagnetic coils in the fault phase of the switch-off rise voltage. At step 115 , the microprocessor 9 outputs the alarm / display with reference to the deviation alarm / display device 42 . If the operation of step 115 is completed, if step 110 has returned NO, or if the operation of step 112 has been completed, the microprocessor 9 proceeds to step 120 .

At step 113 , the microprocessor 9 detects the abnormality in the phase such as. B. the short circuit, the disconnection, the interruption or the like of the electromagnetic coil, the wiring line or the driver element. In step 114 , the microprocessor 9 interrupts the flow of current in groups to interrupt the common ON / OFF element 11 (or 21 ) and for safety interrupts the separate ON / OFF elements 13 and 14 (or 23 and 24 ). At step 112 , the microprocessor 9 avoids duplicating the current flow period of the cascaded electromagnetic coil. This is a means of restricting the injection period to prevent the abnormality related to the interphase shorting across groups 71 in FIG. 7.

In step 120, the microprocessor 9 checks whether there is a duplication of additional detection signals IN13 and IN42 immediately after the falling edge (change time of the logic from "H" to "L") of the separate driver signals SW1-SW4. If the test step 120 returns YES, the microprocessor 9 determines at step 121 which phase of the electromagnetic coil contains the interphase short circuit according to the separated drive signal corresponding to the duplication of the turn-off rise voltage Vs and stores the determination. At step 122 , which follows step 121 , the microprocessor 9 interrupts the common ON / OFF element that drives the electromagnetic coil that contains the interphase short circuit. At step 123 , the microprocessor 9 outputs the alarm / display related to the abnormality alarm / display device 42 . When the operation of step 123 is completed or if a NO is obtained in step 120 , the processor 9 moves to step 106 and then goes back to the start step 100 .

For example, in step 121 , the microprocessor 9 considers the abnormality as that in the first electromagnetic coil 5 or that in the fourth electromagnetic coil 8 with respect to the in-group interphase short-circuit 70 . In step 122 , the microprocessor 9 interrupts the current flow in the groups for interrupting the common ON / OFF element 11 and interrupts the separate ON / OFF elements 13 and 14 for safety.

A non-volatile memory such as B. a RAM memory or EE-PROM, which is maintained by a battery in the event of a power failure, stores the number of the electromagnetic coil including the phase with the detection of the abnormality at step 113 or 121 , the number of the cylinder of the motor and the like. At the time of the maintenance check, the external tool 40 reads out these numbers and displays them in step 104 . In addition, these numbers are initialized and reset in step 102 .

Embodiment 2

Fig. 11 is a detailed electrical circuit diagram showing an error detection circuit of a fuel injector according to the second embodiment of the present invention. The differences from the first exemplary embodiment are primarily described.

In the first driver control circuit 10 of FIG. 11, the current flow of a high-voltage ON / OFF element 11 a is controlled by the steep overexcitation control signal SW13. The current flow of a low voltage side ON / OFF element 11 b is controlled according to the low current hold control signal DT13 output from the low current hold control circuit 19 as described in the first embodiment. A booster circuit 11 raises the voltage of the voltage source 3 . A diode 16 a feeds the first electromagnetic coil 5 and the fourth electromagnetic coil 8 from the booster circuit 11 c through the high-voltage side ON / OFF element 11 a. On the other hand, a diode 16 b feeds the first electromagnetic coil 5 and the fourth electromagnetic coil 8 from the voltage source 3 through the low-voltage ON / OFF element 11 b. In Fig. 11, the common ON / OFF element 11 shown in Fig. 1 is divided into the high-voltage side ON / OFF element 11 a and the low-voltage side ON / OFF element 11 b. However, both the high-voltage side ON / OFF element 11 a and the low-voltage side ON / OFF element 11 b are common ON / OFF elements for feeding the first electromagnetic coil 5 and the fourth electromagnetic coil 8 . The second driver control circuit 20 has the same structure as the first driver control circuit 10 . Therefore, the description of the second driver control circuit 20 is omitted here.

Next, the operation in that described above Structure described in detail.

In the fault detection circuit of the fuel injection device according to the construction shown in FIG. 11, the voltage source 3 is, for example, the battery in a vehicle of a 12-volt DC voltage system (DC12 V), while the booster circuits 11 c and 21 c generate, for example, a high-voltage source of 120 V DC voltage from 12 V DC and drive the electromagnetic coil steeply.

The low-voltage ON / OFF elements 11 b and 21 b carry the low current Ih for the holding operation of the electromagnetic coil. The low-voltage ON / OFF elements 12 b and 21 b carry out a feed directly from the voltage source 3 , whereby a temperature rise in the booster circuits 11 c and 21 c is avoided.

In the fault detection circuit according to the second embodiment, the excitation current of the electromagnetic coils 5 , 6 , 7 and 8 is lower than that of the fault detection circuit in the first embodiment. Therefore, the temperature rise of the common ON / OFF element and the separate ON / OFF element can be reduced.

Embodiment 3

Fig. 12 is a detailed electrical circuit diagram showing an error detection circuit of a fuel injector according to the third embodiment of the present invention. The differences from the first exemplary embodiment are primarily described.

In Fig. 12, a booster circuit 11 d raises the power supply voltage from the power source 3 . The current flow of the high voltage side ON / OFF element 11 a is controlled by the steep overexcitation control signal SW13. The current flow of the low-voltage ON / OFF element 11 b is controlled in accordance with the low-current hold control signal DT13. The diode 16 a feeds the first electromagnetic coil 5 and the fourth electromagnetic coil 8 from the booster circuit 11 d through the high voltage side ON / OFF element 11 a. On the other hand, a diode 16 b feeds the first electromagnetic coil 5 and the fourth electromagnetic coil 8 from the voltage source 3 through the low-voltage ON / OFF element 11 b.

Similarly, the current flow of a high voltage side ON / OFF element 21 a is controlled by the steep overexcitation control signal SW42. The current flow of the low-voltage ON / OFF element 21 b is controlled in accordance with the low-current hold control signal DT42. A diode 26 a feeds the second electromagnetic coil 6 and the third electromagnetic coil 7 from a booster circuit 21 d through the high-voltage side ON / OFF element 21 a. On the other hand, a diode 26 b feeds the second electromagnetic coil 6 and the third electromagnetic coil 7 from the voltage source 3 through the low-voltage ON / OFF element 21 b.

Within the above description, there is only one difference between the exemplary embodiments 2 and 3 in that the booster circuit of the exemplary embodiment 3 is constructed as a common booster circuit 11 d which combines the booster circuits 11 c and 21 c.

The pull-down resistor 12 a is connected in parallel to the commutation diode 12 . The voltage of the voltage source 3 is distributed to a partial resistor 12 b and a partial resistor 12 c. A correction resistor 12 d is a part and the resistor 12 connected between the c pull-down resistor 12th The voltage of the partial resistor 12 c is applied to non-inverting input terminals of comparator circuits 43 and 44 .

Incidentally, a resistance value R12a is determined of the pull-down resistor 12 as a sufficiently smaller than the resistance values R12b, R12d and R 12c of the sub-resistors 12 b and 12 c and the correction resistor 12 d.

Similarly, a pull-down resistor 22 a with a commutation diode 22 is connected in parallel. The voltage of the voltage source 3 is distributed to a partial resistor 22 b and a partial resistor 22 c. A correction resistor 22 is d between the pull-down resistor 22 a and the partial resistor 22 connected c. The voltage of the partial resistor 22 c is applied to non-inverting input terminals of comparator circuits 45 and 46 .

Incidentally, a resistance value R22a determines the pull-down resistor 22 as a sufficiently smaller than the resistance values R22b, R22c and R22d of the partial resistors 22 b and 22 c and the correction resistor 22 d.

The reference symbol 13 b denotes a diode for detecting an increase in the switch-off and the reference symbols 13 c and 13 d indicate partial resistances. The diode 13 b is connected in series with each of the partial resistors 13 c and 13 d. The diode 13 b and the partial resistors 13 c and 13 d are connected between the negative-side connection of the first electromagnetic coil 5 and the negative-side connection of the voltage source 3 . The voltage of the partial resistor 13 d is applied to an inverting input terminal of a comparator circuit 43 .

Similarly, reference numerals 14 b, 23 b and 24 b denote diodes for detecting a switch-off rise and 14 c, 14 d, 23 c, 23 d, 24 c and 24 d denote partial resistances. Similarly, the voltages of the partial resistors 14 d, 23 d and 24 d are subsequently applied to the inverting input connections of comparator circuits 44 to 46 , respectively.

An OR circuit 37 supplies the detection signal IN13 of the logic level "L" to the microprocessor 9 even if one of the comparator circuits 43 or 46 outputs the logic level "L". Similarly, an OR circuit 38 supplies the logic level "L" detection signal IN42 to the microprocessor 9 even if one of the comparator circuits 44 or 45 outputs the logic level "L".

Incidentally, a switch-off rise detection circuit 39 is composed of the comparator circuits 43 , 44 and the comparator circuits 45 , 46 .

Next, the operation of the structure described above will be described, focusing on the operation of the comparator circuit 43 . The high-voltage side ON / OFF element 11 a and the separate ON / OFF element 13 are brought into the conductive state in order to operate the first electromagnetic coil 5 steeply. Next, the high-voltage side ON / OFF element 11 a is interrupted, so that the low-voltage side ON / OFF element 11 b controls the low current for maintaining operation.

Then, since the separate drive signal SW1 takes the logic value "L", the low-voltage side ON / OFF element 12 b and the separate ON / OFF element 13 are interrupted. As shown in Fig. 2, the Ausschaltanstiegsspannung Vs is generated on the negative side terminal of the first electromagnetic coil 5 and the divided voltage from the sub-resistors 13 c and 13 d to the inverting input terminal of the comparator circuit 43 is supplied.

On the other hand, the non-inverting input terminal of the comparator circuit 43 has the low value at this time and the power supply voltage is divided by the resistance values R12b and (R12c / / R12d) because the voltage of both ends of the pull-down resistor 12 a is approximately OV. Here (R12c / / R22d) identifies a parallel resistor combination that combines resistance values R12c and R12d.

Accordingly, as an input voltage of the comparator circuit 43, the voltage of the non-inverting input terminal side becomes lower than that of the inverting input terminal side. The output of the comparator circuit 43 generates the normal detection signal of the logic level "L".

However, when a short circuit 140 shorts the connection point of the first electromagnetic coil 5 and the fourth electromagnetic coil 8 to a power supply line, the partial voltage applied to the non-inverting input terminals of the comparator circuits 43 and 44 has a high value "H" in which the power supply voltage is divided by the resistance values (R12b / / R12d) and R12c. Here (R12b / / R12d) stands for a parallel resistor arrangement that combines the resistance values R12b and R12d.

Accordingly, the voltage of the non-inverting input side as the input voltage of the comparator circuit 43 is higher than that of the inverting input terminal side. As a result, since the output of the comparator circuit 43 becomes logic "H", the result is that the turn-off rise detection has not been carried out.

As described above, the fault detection circuit of the fuel injection device shown in FIG. 12 enables detection of the abnormality of the short circuit on the common ON / OFF element side and is the same in the other electromagnetic coils. With regard to this abnormality of the short circuit, the microprocessor 9 detects the error phase at step 113 of FIG. 10 and stores it. At step 114 , the microprocessor 9 interrupts the common ON / OFF element 11 and the separate ON / OFF elements 13 and 14 and then maintains this state.

When an over-group short circuit 141 causes the short-circuit connection between a common connection point of the first electromagnetic coil and the fourth electromagnetic coil 8 and a common connection point of the second electromagnetic coil 6 and the third electromagnetic coil 7 , if the electromagnetic coil in tandem arrangement does not duplicate in the current flow period, there is no abnormality and even the presence of the short circuit 141 is not detected.

On the other hand, if the electromagnetic coil has a duplication in the current flow period in tandem, the Ausschaltanstiegsspannung Vs can not be detected, because the voltage of the non-inverting input terminals of the comparator circuits 13 b, 14 b, 23 b and 24 b of FIG. Rose 12, when the circuit of the separated ON / OFF element is open. In step 112 of FIG. 10, the microprocessor 9 performs the short circuit treatment of the current flow period to perform the rescue operation.

Embodiment 4

In the embodiments 1, 2 and 3, this is Rescue operation procedures to limit the Injection period used as a countermeasure against the cross-group interphase short-circuit. however can run without the restriction process of Injection period the common ON / OFF element and Similar interruptions to the group flow flow interrupt.

So far the examples of the four-cylinder engine described. Even in the case of the six-cylinder engine or the Eight-cylinder engines can be the common ON / OFF elements split into two groups. Furthermore can use the common ON / OFF elements that make up the grouping include, which consist of three parts (six-cylinder) or four parts (eight-cylinder) are used.

If a gasoline engine is used as the engine, if the fuel injection control device one Ignition control function of the engine includes the correction of the Ignition timing and the correction of Fuel injection control performed to drive to shorten the time of occurrence of an abnormality. Therefore, the device can achieve an improvement in Run a more stable rescue operation.

In addition, the deviation alarm / display Device, for example, indicate the state that the Driving is shortened to the state that the Fuel supply is completely cut off due to the abnormality regarding the whole group or the Stop process of fuel injection based on the Interruption, short circuit, misfire or similar to the ignitor group. That means the Deviation Alarm / Display Device Alarm / Can perform display functions integrally or hierarchically.

As described above, according to the Fault detection circuit of the fuel injector according to the present invention the individual Power off rise detection circuit, group detection of short circuit, disconnection and interruption in the electromagnetic fuel injection control coil, ON / OFF element, its wiring line and the like. In addition, the Switch-off rise detection circuit the detection of the fault of the interphase short by Fault assessment device and the Duplikationsbeurteilungsvorrichtung. They are even further common ON / OFF elements divided into several groups, whereby the stable rescue operation can be carried out.

The current control related to the electromagnetic coil is carried out on the side of the common ON / OFF Element. Therefore, the tension of both ends of the separate ON / OFF element monitors, which the Switch-off rise voltage can be easily detected.

Since the switch-off rise voltage by the electrical Potential of both ends of the electromagnetic coil is detected even the abnormality of the short circuit between the common ON / OFF elements and the mutual Short circuits across groups can be easily detected.

The OR gate connection regarding the Shutdown rise detection circuit is in reasonable Way implemented by the OR circuit. Therefore, that can Duplicate the cutoff rise voltage can be checked and the input points of the microprocessor or the number of Hardware units can be reduced.

Since the common ON / OFF element the steep Overexcitation control and low current control for the Holding operation in itself is the structure of the Feed control circuit simplified and it will be a good one Effect achieved, even with low dielectric strength electromagnetic coil.

The common ON / OFF element is to run the steep Overdischarge control divided into the high voltage and Low current control for the holding operation by the Low voltage. Accordingly, the amount of current flow is common ON / OFF element reduces and the heat release is reduced. Accordingly, the device can be miniaturized become.

Because the single overexcitation booster circuit is the steep one Overexcitation can run in relation to everyone electromagnetic coils, this leads to the Miniaturization of the device and cost reduction of the Contraption.

If the common ON / OFF element is associated with the If the abnormality is interrupted, the electromagnetic coil with the uninterrupted common ON / OFF element is connected, stable Carry out rescue operation because the common ON / OFF Elements appropriately divided into several groups are.

If the abnormality of the short circuit over different groups occurs, the Current flow period of the pulse group of the control signals shortened, which leads to a more stable rescue operation can be.

The alarm or display is based on the Deviation of the error or the duplication of the Switch-off rise voltage output. Accordingly, the alarm issued for all commonly occurring faults and this can increase security.

The microprocessor is with the interface circuit provided for connection to the external tool. This will the identification information of the electromagnetic coil, in which an abnormality has occurred, read out and the read information is displayed on the external tool. Therefore, the efficiency of the maintenance check can be increased and the stored information can easily be extracted from the external Tool can be initialized.

Claims (11)

1. A fuel injector fault detection circuit comprising:
a plurality of electromagnetic coils for driving an electromagnetic fuel injection valve with respect to each cylinder of a multi-cylinder engine;
a microprocessor for generating a pulse group of a drive signal and a steep overexcitation control signal;
a plurality of separate ON / OFF elements for driving the electromagnetic coils by sequentially performing ON / OFF operation according to the pulse group of a drive signal generated by the microprocessor 9 ;
a plurality of groups of common ON / OFF elements for driving a group supply in electromagnetic coils into the group, which is formed from at least a plurality of electromagnetic coils with the interval of the fuel injection sequence in a two or multi-line degree, according to the steep overexcitation control signal generated by the microprocessor; and
a plurality of cutoff rise detection circuits for detecting a cutoff rise voltage induced by opening the circuit of the separated ON / OFF element corresponding to the electromagnetic coil is involved in at least one difference group,
wherein the processor compares detection signals detected by the plurality of turn-off rise detection circuits for judging an abnormality based on whether an error of the detection signal and a duplication of the detection signal are included. 2. Fault detection circuit one The fuel injector according to claim 1, wherein each of the turn-off rise detection circuits Switch-off rise voltage detected by detecting that a voltage value at both ends of the separate ON- / OFF element becomes higher than a voltage source when the circuit of this separate ON / OFF element is open. 3. Fault detection circuit one The fuel injector according to claim 1, wherein each of the turn-off rise detection circuits Cutoff rise voltage detected by detecting that a voltage of a negative-side connection of the electromagnetic coil is higher than that of one Supply connection, which is connected to the common ON / OFF Element is connected when the circuit of the separate ON / OFF element and the circuit of this common ON / OFF element are open. 4. Fault detection circuit one The fuel injector according to claim 1, wherein the common ON / OFF element is an OR circuit for Implement an OR gate combination of Contains detection signals by the respective OFF rise detection circuits with respect to the contained in different groups electromagnetic coil is output and the Microprocessor judges an abnormality based on an output of the OR circuit. 5. Fault detection circuit one The fuel injector according to claim 1, wherein each of the common ON / OFF elements corresponding to the steep overexcitation control signal is operated that is generated by the microprocessor and one Low current hold control signal to get this Operation of the electromagnetic coil. 6. The fault detection circuit of a fuel injection device according to claim 1, wherein an overexcitation booster circuit is set up to raise a power supply voltage and the common ON / OFF element is composed of:
a high voltage side ON / OFF element for driving the feed into the electromagnetic coil through the overexcitation booster circuit; and
a low voltage side ON / OFF element for driving the supply into the electromagnetic coil in accordance with the low current hold control signal for maintaining the operation of the electromagnetic coil. 7. Fault detection circuit one The fuel injector of claim 6, wherein the high-voltage side ON / OFF elements that Overexcitation booster circuit share and that Overexcitation booster circuit is shared in terms of all electromagnetic coils. 8. Fault detection circuit one The fuel injector according to claim 1, wherein, if the microprocessor based on an abnormality judged the detection signal that from the Shutdown rise detection circuit a device provided to interrupt a group current flow is to interrupt the corresponding common ON- / OFF element and the separate ON / OFF element that connected in series with the common ON / OFF element and the electromagnetic coil that is in one from the one containing the interrupted ON / OFF element Group different group is included one Rescue operation. 9. Fault detection circuit one The fuel injector of claim 8, wherein if the microprocessor based on an abnormality judged an error of the cutoff rise voltage, in the case where there is a duplication of the Current flow period of the electromagnetic coil in Tandem formation gives a shortening treatment is performed with respect to a current flow period of the Pulse group of driver signals. 10. Fault detection circuit one The fuel injector according to claim 1, wherein a device for reporting an abnormality Reception of an abnormality signal is provided and when the microprocessor judges an abnormality based on the detection signal from the Power off rise detection circuit has been detected is, the abnormality signal is output to this Device for reporting the abnormality. 11. Fault detection circuit of a The fuel injector according to claim 1, wherein the microprocessor is equipped with a Connection interface circuit with an external Tool.