JP2012241668A - Solenoid valve driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve driving device in which the configuration for supplying a peak current and a hold current to a solenoid valve can be simplified.SOLUTION: A capacitor C capable of supplying the peak current to coils 11a, 12a is connected in parallel with a power feeding path to the coils 11a, 12a from a DC power source B. Switches 22a, 22b are each disposed on the low voltage side (low side) of the coils 11a, 12a, wherein the on-state at the beginning of a driving period allows the high voltage of the capacitor C to be applied so as to supply the peak current to the coils 11a, 12a, and the switching operation after supplying the peak current allows the power source voltage of DC power source B to be applied so as to supply the hold current to the coils 11a, 12a.

Description

  The present invention relates to a solenoid valve driving device that drives a solenoid valve.

  Conventionally, a solenoid valve driving device that drives a solenoid valve maintains a peak current for promptly opening the solenoid valve at the start of a set drive period and the open state of the solenoid valve until the drive period ends. For this purpose, a hold current smaller than the peak current is supplied to the solenoid valve. As described above, an electromagnetic valve driving device disclosed in Patent Document 1 is known as an electromagnetic valve driving device capable of supplying a peak current and a hold current to an electromagnetic valve.

  The electromagnetic valve driving device turns on a switching element for driving an electromagnetic valve provided on the downstream side of a coil of an injector (electromagnetic valve) during a set driving period, and at the start of the driving period, a peak current The supply switching element is also turned on, the high voltage charged in the capacitor is applied to the injector coil to supply the peak current, and then the hold current supply switching element is turned on until the end of the driving period. The hold current is supplied to the coil of the injector by performing the off / control.

  Similarly, in the electromagnetic load driving device disclosed in Patent Document 2 below, when the injector is driven, the high voltage charged in the capacitor is applied to the injector coil by turning on the peak current supply transistor. Peak current is supplied. After the transistor is turned on, the hold current supply transistor is periodically turned on / off, whereby a constant current (hold current) based on the power supply voltage is supplied to the injector solenoid.

JP 2008-063993 A JP 2002-180878 A

  By the way, in order to supply currents of different magnitudes between the peak current for promptly opening the solenoid valve and the hold current for maintaining the opened state of the solenoid valve, the above Patent Documents 1 and 2 are used. As in the disclosed configuration, it is necessary to provide both a current supply circuit (such as a switching element) for supplying peak current and a current supply circuit (such as a switching element) for supplying hold current. Thus, since it is necessary to provide at least two current supply circuits as a configuration for supplying both currents, there is a problem that simplification of the drive circuit for driving the solenoid valve becomes difficult and becomes an impediment to cost reduction. .

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electromagnetic valve driving device capable of simplifying a configuration for supplying a peak current and a hold current to an electromagnetic valve. There is.

  In order to achieve the above object, in the electromagnetic valve driving device according to claim 1, the coil of the electromagnetic valve quickly opens the electromagnetic valve at the start of a set driving period. An electromagnetic valve driving device that supplies a peak current of the first and a hold current smaller than the peak current that is a current for holding the solenoid valve in an open state until the driving period ends. A capacitor capable of supplying a current to the coil; and charging means for charging the capacitor by generating a high voltage higher than a power supply voltage from a DC power supply, wherein the capacitor supplies power to the coil from the DC power supply. The capacitor is connected in parallel to the path, arranged on either the high potential side or the low potential side of the coil, and turned on at the start of the driving period. A switching element that applies a high voltage to supply the peak current to the coil, starts switching after the peak current is supplied, and applies a power supply voltage of the DC power supply to supply the hold current to the coil. It is characterized by providing.

  According to a second aspect of the present invention, in the electromagnetic valve driving device according to the first aspect, the capacitance of the capacitor is set so as to be an upper limit current value at which the peak current can be supplied to the coil. It is characterized by.

  According to a third aspect of the present invention, in the electromagnetic valve driving device according to the first or second aspect, an electromagnetic valve group including two or more electromagnetic valves that are not in the open state at the same time is a driving target, and the switching is performed. The element is arranged on the high potential side of the coil of each solenoid valve that constitutes the solenoid valve group, and the peak current and the hold with respect to the coil of the solenoid valve to be opened in the solenoid valve group It is configured to be able to supply current.

  According to a fourth aspect of the present invention, there is provided the electromagnetic valve drive device according to the third aspect, further comprising switch means shared so that the low potential side of the coil of each electromagnetic valve constituting the electromagnetic valve group can be grounded. The means is characterized in that, when any one of the solenoid valves constituting the solenoid valve group is in the open state, all the low potential sides of the coils of the solenoid valves are grounded.

  According to a fifth aspect of the present invention, in the electromagnetic valve driving device according to the first or second aspect, an electromagnetic valve group including two or more electromagnetic valves that do not simultaneously open the valve is an object to be driven, and the switching is performed. The element is disposed on the low potential side of the coil of each solenoid valve constituting the solenoid valve group, and the peak current and the hold with respect to the coil of the solenoid valve to be opened in the solenoid valve group It is configured to be able to supply current.

  A sixth aspect of the present invention is the electromagnetic valve driving device according to any one of the third to fifth aspects, wherein the capacitor, the charging means, and the switching element are set as a set with respect to the electromagnetic valve group. A plurality of sets of supply means are provided.

  A seventh aspect of the invention is the electromagnetic valve driving device according to any one of the third to fifth aspects, wherein the charging means includes a plurality of the capacitors, and the charging means includes the plurality of capacitors. The switching element can supply the peak current by applying a high voltage of any one of the plurality of capacitors to the coil of the solenoid valve to be opened. It is comprised by this.

  According to an eighth aspect of the present invention, in the electromagnetic valve driving device according to any one of the third to fifth aspects, a plurality of the electromagnetic valve groups are to be driven, and the capacitor is provided for each of the electromagnetic valve groups. Current supply means including the charging means and the switching element as a set is provided, and the switching element of the current supply means is the same set of the coil of the solenoid valve to be opened. The peak current can be supplied by applying any one of a high voltage of a capacitor and a high voltage of the other set of capacitors.

  In the first aspect of the present invention, the capacitor capable of supplying the peak current to the coil is connected in parallel to the power supply path from the DC power supply to the coil. Then, by turning on at the start of the driving period, a high voltage of the capacitor is applied to supply the peak current to the coil, and switching is started after the supply of this peak current to apply the power supply voltage of the DC power supply. The switching element for supplying the hold current to the coil is disposed on either the high potential side (high side) or the low potential side (low side) of the coil.

As described above, since the hold current is supplied by applying the power supply voltage of the DC power supply after the peak current is supplied by applying the high voltage of the capacitor according to the operation of the switching element, the peak Different currents can be supplied to the coil without providing two current supply circuits for supplying current and holding current.
Therefore, the configuration for supplying the peak current and the hold current to the electromagnetic valve can be simplified.

  In the invention of claim 2, since the capacitance of the capacitor is set so as to be an upper limit current value at which the peak current can be supplied to the coil, the capacitance of the capacitor can be reduced, and the size of the capacitor can be reduced. And cost reduction can be achieved.

  In the invention of claim 3, the switching element is arranged on the high potential side of the coil of each solenoid valve that constitutes the solenoid valve group, and has a peak with respect to the coil of the solenoid valve to be opened in the solenoid valve group. A current and a hold current can be supplied. Thus, even if two or more solenoid valves that do not open at the same time are to be driven, the peak current and hold current can be set as desired according to the operation of the switching element arranged on the high potential side of each coil. Can be supplied to the coil.

  In the invention of claim 4, when any one of the solenoid valves constituting the solenoid valve group is opened, all the low potential sides of the coils of the solenoid valves are grounded by the switch means.

  For example, when two solenoid valves that do not open at the same time are to be driven, in the conventional configuration, the voltage from the capacitor or the DC power supply is applied to the coils on the low potential side of the coils of both solenoid valves. As switch means, a switch for grounding the low potential side is provided. In such a configuration, the coil of one solenoid valve to be opened (hereinafter referred to as a drive coil) is closed (on state) and the low potential side is grounded so that the coil is predetermined. Is applied to the coil of the other solenoid valve (hereinafter referred to as a resting coil), but the switch on the low potential side remains in the open state (off state). . At this time, the high potential side and the low potential side of the resting coil have the same potential as the high potential side of the drive coil, and the low potential side of the drive coil becomes the ground potential.

  For this reason, the average voltage (hereinafter referred to as common mode voltage) of the high potential side voltage and the low potential side voltage in the pause coil is larger than the common mode voltage in the drive coil. Since the electromagnetic noise increases as the common mode voltage increases, the electromagnetic noise caused by the common mode voltage of the solenoid valve that is not being driven becomes larger than the electromagnetic noise of the solenoid valve that is being driven.

  Therefore, in the invention of claim 4, when the voltage is applied to the coil (drive coil) of the solenoid valve to be opened by the switching element arranged on the high potential side, each of the solenoid valves is switched by the switch means. All the low potential sides of the coils are grounded. For this reason, in a solenoid valve that is different from the solenoid valve that should be opened, the high-potential side and low-potential side of the coil (resting coil) become ground potential, and the common mode voltage decreases, so electromagnetic noise caused by the common mode voltage The influence of can be suppressed.

  According to the invention of claim 5, the switching element is disposed on the low potential side of the coil of each solenoid valve constituting the solenoid valve group, and peaks relative to the coil of the solenoid valve to be opened in the solenoid valve group. A current and a hold current can be supplied. Thus, even if two or more solenoid valves that do not open at the same time are to be driven, the peak current and hold current can be set as desired according to the operation of the switching element arranged on the low potential side of each coil. Can be supplied to the coil.

  In the invention of claim 6, since a plurality of sets of current supply means including a capacitor, a charging means and a switching element are provided for the solenoid valve group, even if the capacitor of one current supply means is in a charged state. By using the fully charged capacitor of the other current supply means, it is possible to shorten the time from driving one solenoid valve of the solenoid valve group to driving another solenoid valve.

  In the invention of claim 7, a plurality of capacitors are provided for one charging means, and the charging means is configured to be able to charge the plurality of capacitors. And a switching element is comprised so that a peak electric current can be supplied by applying any one high voltage of the some capacitor | condenser with respect to the coil of the solenoid valve which should be made into a valve opening state. As a result, even if one capacitor is in a charged state, another fully charged capacitor can be used. Therefore, after driving one solenoid valve in the solenoid valve group, another solenoid valve is driven. Can be shortened.

  In the invention according to claim 8, a plurality of solenoid valve groups are to be driven, and current supply means each including a capacitor, a charging means and a switching element are provided for each of the solenoid valve groups. The switching element of the current supply means applies a peak current by applying either the high voltage of the same set of capacitors or the high voltage of another set of capacitors to the solenoid valve coil to be opened. It is configured to be available. As a result, even if the same set of capacitors is in a charged state, another set of fully charged capacitors can be used. Therefore, after driving one solenoid valve of the solenoid valve group, another solenoid valve is used. Can be shortened.

It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 1st Embodiment. It is a time chart which shows operation | movement and an effect | action of a solenoid valve drive device in the drive period of a solenoid valve. FIG. 3A is an explanatory diagram for explaining an energization state at the time of peak current supply, and FIG. 3B is an explanatory diagram for explaining a recovery state to the capacitor. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 2nd Embodiment. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 3rd Embodiment. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 4th Embodiment. FIG. 7A is an explanatory diagram for explaining the energized state at the time of peak current supply, and FIG. 7B is an explanatory diagram for explaining the state of recovery to the capacitor. 8A is a time chart showing the voltage change of the common mode voltage in the pause coil of FIG. 6, and FIG. 8B is a time chart showing the voltage change of the common mode voltage in the drive coil of FIG. is there. It is a graph for demonstrating the reduction effect with respect to the electromagnetic noise resulting from the common mode voltage of a solenoid valve. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 5th Embodiment. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 6th Embodiment. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the solenoid valve drive device which concerns on 7th Embodiment. It is a block diagram which shows schematic structure of the fuel-injection control apparatus which employ | adopted the conventional solenoid valve drive device. 14A is a time chart showing the voltage change of the common mode voltage in the pause coil of FIG. 13, and FIG. 14B is a time chart showing the voltage change of the common mode voltage in the drive coil of FIG. is there.

[First Embodiment]
Hereinafter, an electromagnetic valve driving device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a fuel injection control device 10 employing a solenoid valve drive device 20 according to the first embodiment.

  A fuel injection control device 10 shown in FIG. 1 includes, for example, an electromagnetic solenoid unit injector (hereinafter simply referred to as electromagnetic valves 11 and 12) for supplying fuel to each cylinder of a two-cylinder engine mounted on a vehicle, And an electromagnetic valve driving device 20 for driving the valves 11 and 12.

  The solenoid valves 11 and 12 are normally closed (normally closed type) solenoid valves having coils 11a and 12a, respectively, and when the coils 11a and 12a are energized, a valve body (not shown) acts as a biasing force of the return spring. The fuel is injected by moving to the valve opening position and maintaining the valve open state. Further, when the energization of the coils 11a and 12a is interrupted, the valve body returns to the original closed position, and fuel injection is stopped. These electromagnetic valves 11 and 12 are driven and controlled by the electromagnetic valve driving device 20 so that they are not simultaneously opened.

  The solenoid valve driving device 20 has, as output terminals, an output terminal P1 to which the high potential side (high side) of the coil 11a of the solenoid valve 11 is connected, and an output terminal P2 to which the low potential side (low side) of the coil 11a is connected. And an output terminal P3 to which the high potential side of the coil 12a of the solenoid valve 12 is connected, and an output terminal P4 to which the low potential side of the coil 12a is connected. The electromagnetic valve driving device 20 is used for driving the electromagnetic valve 11 provided in series between the other end of the current detection resistor R1 whose one end is connected to the ground line (GND = 0V) and the output terminal P2. Switch 22a, switch 22b for driving solenoid valve 12 provided in series between the other end of current detection resistor R1 and output terminal P4, anode connected to ground line, cathode connected to output terminal P1 and output A diode D2 connected to the terminal P3, a capacitor C for causing a peak current to quickly shift any one of the solenoid valves 11 and 12 to the valve open state, and the positive side of the capacitor C Is connected to the output terminal P1 and the output terminal P3, and a high voltage higher than the power supply voltage VB by boosting the power supply voltage VB of the DC power supply (battery) B A DCDC converter 24 for charging the capacitor C by generating and supplying the high voltage to the capacitor C via the diode D1, and a control circuit 21 comprising a switch 22a, 22b, 23 and a microcomputer for controlling the DCDC converter 24, etc. It has. The DCDC converter 24 may correspond to an example of a “charging unit” described in the claims.

  As shown in FIG. 1, the capacitor C is connected in parallel to the power supply path from the DC power source B to the coils 11a and 12a. The capacitance of the capacitor C is described later with respect to the coils 11a and 12a. The peak current is set to an upper limit current value that can be supplied. Specifically, for example, since the peak current is 22 A and the inductances of the coils 11 a and 12 a are 80 μH, the capacitance of the capacitor C is set to 33 μF. Thus, the capacitance of the capacitor C is set according to the inductance of the coils 11a and 12a, and can be preferably set to about 20 μF to 60 μF. Moreover, each switch 22a, 22b, 23 mentioned above is switching elements, such as MOSFET, for example.

  Further, an energy recovery path for recovering flyback energy from the coil 11a to the capacitor C is provided between the output terminal P2 and the positive electrode side of the capacitor C. On the energy recovery path, A diode D3a for current direction control is provided with the cathode on the capacitor C side. Similarly, an energy recovery path for recovering flyback energy from the coil 12a to the capacitor C is provided between the output terminal P4 and the positive electrode side of the capacitor C, and on this energy recovery path. Is provided with a diode D3b for current direction control with the cathode as the capacitor C side.

  On the other hand, the DCDC converter 24 includes an inductor 24a and a switch 24b provided in series between the DC power supply B and the ground line. When the switch 24b is turned on / off, energy stored in the inductor 24a is transferred. It is a well-known one that charges the capacitor C through the diode D1.

  Next, the operation of the electromagnetic valve drive device 20 configured as described above will be described with reference to FIGS. 2 is a time chart showing the operation and action of the solenoid valve drive device 20 during the drive period of the solenoid valve 11, FIG. 2A shows the voltage change of the capacitor C, and FIG. FIG. 2C shows the on / off control state of the switch 23, and FIG. 2D shows the on / off control state of the switch 22a. FIG. 3A is an explanatory diagram for explaining the energized state at the time of peak current supply, and FIG. 3B is an explanatory diagram for explaining the recovery state to the capacitor C.

  First, the control circuit 21 sets a drive period in which the coils 11a and 12a of the electromagnetic valves 11 and 12 should be energized for each cylinder based on engine operation information such as the engine speed and the accelerator opening, and the coil 11a. The switch 23 is turned on only during the drive period in which the current is to be supplied.

  Further, the control circuit 21 operates the DCDC converter 24 before the drive period of the two solenoid valves 11 and 12 starts, and the capacitor C is charged with the charging voltage (positive voltage) of the capacitor to the target voltage Vc1. Charge until This target voltage Vc1 is set so as to be an upper limit current value at which a peak current can be supplied to the coils 11a and 12a. In this embodiment, the target voltage Vc1 is set to 50V, for example.

  The control circuit 21 turns on the switch corresponding to the electromagnetic valve at the start timing of the driving period of any of the electromagnetic valves, and simultaneously turns on the switch 23. For example, at the start timing of the drive period of the solenoid valve 11, as shown in FIGS. 2C and 2D, the switch 22a is turned on, and at the same time, the switch 23 is turned on.

  For this reason, when the positive side of the capacitor C is connected to the output terminal P1 via the switch 23, the energy charged in the capacitor C is released to the coil 11a, and the high voltage of the capacitor C is applied to the coil 11a. (See arrow α1 in FIG. 3A). At this time, as shown in FIGS. 2 (A) and 2 (B), the coil 11a has a large current for quickly shifting the solenoid valve 11 to the valve-opened state by discharging the capacitor C, that is, Peak current flows.

  When the capacitor C is discharged, the wraparound from the output terminal P1 side to the power supply line side, which becomes a high potential, is prevented by the diode D2. Furthermore, even if the switch 22a is turned on, the diode D3a prevents the current from flowing directly from the positive side of the capacitor C to the switch 22a via the energy recovery path.

  Then, after the switch 22a is turned on, the control circuit 21 detects the coil current flowing through the coil 11a from the voltage generated in the resistor R1, and when the coil current reaches the target current value Ip of the peak current, the control circuit 21 turns off the switch 22a. . Note that the switch 22a may be configured to be turned on for a predetermined time without detecting the coil current flowing through the coil 11a.

  In this way, at the start of the drive period of the electromagnetic valve 11, the switch 22a is turned on, and the accumulated energy of the capacitor C is released to the coil 11a, whereby a peak current flows through the coil 11a, and the electromagnetic valve 11 The valve opening response becomes faster.

  Then, after the switch 22a is turned off, the control circuit 21 switches the switch 22a so that the coil current detected by the voltage generated in the resistor R1 becomes a constant current Ih smaller than the target current value of the peak current. (ON / OFF control) is started. This constant current is a current for holding the open state of the solenoid valve (hereinafter referred to as a hold current). After the coil current reaches the target current value Ip of the peak current, the switch 22a is turned on / off. Is repeated, and the average value of the coil current is controlled to the hold current (see FIG. 2B).

  At the time of constant current control by such a switch 22a, the hold current flows to the coil 11a through the switch 23 by the energy stored in the capacitor C and the power supply voltage VB of the DC power supply B, and the solenoid valve 11 is caused by the hold current. The valve is kept open. That is, the switch 22a is arranged on the low potential side of the coil 11a and is turned on at the start of the driving period, so that the high voltage of the capacitor C is applied to supply the peak current to the coil 11a. By starting the switching after supply, the power supply voltage of the DC power supply B is applied to function as a switching element that supplies the hold current to the coil 11a.

  Further, the diode D2 functions as a current return diode for returning current from the ground line side to the coil 11a when the switch 22a is turned off while the switch 23 is turned on. For this reason, when the switch 22a is turned off during the on / off control of the switch 22a, the current flowing through the coil 11a is a current flowing back through the diode D2.

  After that, when the driving period ends, the control circuit 21 turns off the switch 23, ends the on / off control (that is, constant current control) of the switch 22a, and keeps the switch 22a in the off state. Then, energization to the coil 11a is stopped, the electromagnetic valve 11 is closed, and fuel injection by the electromagnetic valve 11 is ended.

  When the switch 22a and the switch 23 are turned off, flyback energy is generated in the coil 11a. The flyback energy is supplied from the output terminal P2 of the coil 11a to the capacitor C through the energy recovery diode D3a. (See arrow α2 in FIG. 3B).

  On the other hand, the control circuit 21 restarts charging of the capacitor C by the DCDC converter 24 after turning off the switch 23. This is to prepare for the next solenoid valve drive. Note that the control circuit 21 prohibits the DCDC converter 24 from charging the capacitor C in order to stabilize the discharge current from the capacitor C while the switch 23 is on.

  After the solenoid valve 11 is closed in this way, at the start timing of the drive period of the solenoid valve 12, the switch 22b is turned on while the switch 22a is turned off, and at the same time, the switch 23 is turned on.

  For this reason, when the positive side of the capacitor C is connected to the output terminal P3 via the switch 23, the energy charged in the capacitor C is released to the coil 12a, and the high voltage of the capacitor C is applied to the coil 12a. A peak current flows through the coil 12a. Then, after the switch 22b is turned on, the control circuit 21 turns off the switch 22b when the coil current flowing through the coil 12a reaches the target current value of the peak current. In this way, at the start of the drive period of the electromagnetic valve 12, the switch 22b is turned on, and the accumulated energy of the capacitor C is released to the coil 12a, whereby a peak current flows through the coil 12a, and the electromagnetic valve 12 The valve opening response becomes faster.

  When such a capacitor C is discharged, the wraparound from the output terminal P3 side to the power supply line side, which becomes a high potential, is prevented by the diode D2. Furthermore, even if the switch 22b is turned on, the diode D3b prevents current from flowing directly from the positive side of the capacitor C to the switch 22b via the energy recovery path.

  The control circuit 21 performs the on / off control of the switch 22b so that the coil current detected by the voltage generated in the resistor R1 becomes the hold current after the switch 22b is turned off. 12 is kept open.

  The diode D2 functions as a current return diode for causing current to flow from the ground line side to the coil 12a when the switch 22b is turned off while the switch 23 is turned on. For this reason, when the switch 22b is turned off during the on / off control of the switch 22b, the current flowing through the coil 12a is a current that circulates through the diode D2.

  After that, when the drive period ends, the control circuit 21 turns off the switch 23, ends the on / off control (that is, constant current control) of the switch 22b, and keeps the switch 22b in the off state. Then, energization of the coil 12a is stopped, the electromagnetic valve 12 is closed, and fuel injection by the electromagnetic valve 12 is terminated.

  Further, when the switch 22b and the switch 23 are turned off, flyback energy is generated in the coil 12a. The flyback energy is supplied from the output terminal P4 of the coil 12a to the capacitor C through the energy recovery diode D3b. Recovered in the form.

  As described above, in the solenoid valve drive device 20 according to the present embodiment, the capacitor C that can supply the peak current to the coils 11a and 12a is in parallel with the power supply path from the DC power supply B to the coils 11a and 12a. It is connected. Then, when the driving period starts, the high voltage of the capacitor C is applied to supply the peak current to the coils 11a and 12a, and the switching of the DC power supply B is started by starting the switching after the peak current is supplied. Switches 22a and 22b for applying a voltage and supplying a hold current to the coils 11a and 12a are arranged on the low potential side (low side) of the coils 11a and 12a, respectively.

In this way, according to the operation of the switches 22a and 22b, the peak current is supplied by applying the high voltage of the capacitor C, and then the hold current is supplied by applying the power supply voltage of the DC power supply B. Therefore, different magnitudes of current can be supplied to the coils 11a and 12a without providing two current supply circuits for peak current supply and hold current supply.
Therefore, the configuration for supplying the peak current and the hold current to the electromagnetic valves 11 and 12 can be simplified. Such simplification makes it possible to reduce the size and cost of the electromagnetic valve driving device.

  Further, since the capacitance of the capacitor C is set to an upper limit current value at which the peak current can be supplied to the coils 11a and 12a, the capacitance of the capacitor C can be reduced and the capacitance of the capacitor C can be reduced. Miniaturization and cost reduction can be achieved.

  In the drive period of the electromagnetic valve 11, not only the switch 22a is turned on / off while the switch 23 is turned on, but both the switch 23 and the switch 22a may be turned on / off at the same timing. In the drive period of the solenoid valve 12, the switch 22b is not limited to ON / OFF control while the switch 23 is ON, but both the switch 23 and the switch 22b may be ON / OFF controlled at the same timing.

[Second Embodiment]
Next, a solenoid valve driving apparatus according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve drive device 20a according to the second embodiment.
The electromagnetic valve drive device 20a according to the second embodiment is an electromagnetic valve that injects fuel into each cylinder of a four-cylinder engine and does not open simultaneously with respect to the first embodiment. The electromagnetic valve group G composed of 11 to 14 is configured to be driven and controlled.

  Specifically, as shown in FIG. 4, the solenoid valve driving device 20 a is connected to the high potential side (high side) of the coil 13 a of the solenoid valve 13 as an output terminal in addition to the output terminals P <b> 1 to P <b> 4. The output terminal P5, the output terminal P6 to which the low potential side (low side) of the coil 13a is connected, the output terminal P7 to which the high potential side of the coil 14a of the solenoid valve 14 is connected, and the low potential side of the coil 14a are connected. And an output terminal P8. In addition to the switches 22a and 22b, the solenoid valve drive device 20a includes a switch 22c for driving the solenoid valve 13 provided in series between the other end of the current detection resistor R1 and the output terminal P6, and a current A switch 22d for driving the electromagnetic valve 14 provided in series between the other end of the detection resistor R1 and the output terminal P8.

  An energy recovery path for recovering flyback energy from the coil 13a to the capacitor C is provided between the output terminal P6 and the positive side of the capacitor C. On the energy recovery path, A diode D3c for current direction control is provided with the cathode on the capacitor C side. Similarly, an energy recovery path for recovering flyback energy from the coil 14a to the capacitor C is provided between the output terminal P8 and the positive electrode side of the capacitor C. On the energy recovery path, Is provided with a diode D3d for current direction control with the cathode as the capacitor C side.

  Thus, in the solenoid valve drive device 20a according to the second embodiment, the switches 22a to 22d are arranged on the low potential side of the coils 11a to 14a of the solenoid valves 11 to 14 constituting the solenoid valve group G. A peak current and a hold current can be supplied to the coil of the solenoid valve to be opened in the solenoid valve group G. As described above, even if four solenoid valves that are not simultaneously opened are driven, the peak current and the hold current are set as desired according to the operation of one of the switches arranged on the low potential side of each coil. Can be supplied to the coil. The solenoid valve group G to be driven by the solenoid valve driving device 20a is not limited to the four solenoid valves that are not simultaneously opened, and is composed of three solenoid valves that are not simultaneously open. Alternatively, it may be composed of five or more solenoid valves that do not open simultaneously.

[Third Embodiment]
Next, a solenoid valve driving apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve driving device 20b according to the third embodiment.
In the solenoid valve drive device 20b according to the third embodiment, a current supply unit including a capacitor, a DCDC converter (charging unit), and a switch as a set with respect to the solenoid valve group G described above is provided in the solenoid valve group G. On the other hand, two sets are provided so as to be able to supply current.

  Specifically, as shown in FIG. 5, the solenoid valve drive device 20b includes a first capacitor Ca for causing a peak current to flow through the coils 11a to 14a, and a positive side of the first capacitor Ca as output terminals P1 and P3. , P5, P7, a back-flow prevention diode D4a disposed between the switch 25a and each output terminal, and a power supply voltage VB of the DC power supply (battery) B And a DCDC converter 24 that charges the first capacitor Ca by generating a high voltage higher than the power supply voltage VB and supplying the high voltage to the first capacitor Ca via the diode D1a. Supply means 31 are provided. The solenoid valve driving device 20b connects the second capacitor Cb for causing the peak current to flow through the coils 11a to 14a, and the positive side of the second capacitor Cb to any one of the output terminals P1, P3, P5, and P7. Switch 25b, a backflow prevention diode D4b disposed between the switch 25b and each output terminal, and a power supply voltage VB of a DC power supply (battery) B that is boosted to a voltage higher than the power supply voltage VB. A second current supply means 32 having a DCDC converter 24c for generating a voltage and charging the second capacitor Cb by supplying the high voltage to the second capacitor Cb via the diode D1b is provided.

  As described above, in the solenoid valve driving device 20b according to the third embodiment, the first current supply means 31 and the second current, which are a set of the capacitor, the DCDC converter (charging means), and the switch for the solenoid valve group G. Since the supply means 32 is provided, even when the first capacitor Ca of the first current supply means 31 is in a charged state, the switch 25b is turned on so that the fully charged second capacitor Cb of the second current supply means 32 is set. Can be used. As described above, when the peak current is supplied from the second capacitor Cb by turning on the switch 25b, the voltage of the output terminals P1, P3, P5, and P7 is changed by the diode D4a to the first capacitor Ca. Current is prevented from flowing through the parasitic diode of the switch 25a. Even when the second capacitor Cb of the second current supply means 32 is in a charged state, the switch 25a can be turned on to use the fully charged first capacitor Ca of the first current supply means 31. In this way, when the switch 25a is turned on to supply the peak current from the first capacitor Ca, the diode D4b causes the voltages at the output terminals P1, P3, P5, and P7 to be changed to the second capacitor Cb. Current is prevented from flowing through the parasitic diode of the switch 25b.

  Thereby, the time (interval time) until it drives another solenoid valve after driving one solenoid valve of the solenoid valve group G can be shortened. The solenoid valve group G to be driven by the solenoid valve drive device 20b is not limited to the four solenoid valves that are not simultaneously opened, and is composed of three solenoid valves that are not simultaneously open. Alternatively, it may be composed of five or more solenoid valves that do not open simultaneously.

  Note that the current supply means is not limited to two sets that can supply current to the electromagnetic valve group G, but three or more sets may be provided in order to further shorten the interval time.

[Fourth Embodiment]
Next, a solenoid valve driving apparatus according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve driving device 20c according to the fourth embodiment. FIG. 7A is an explanatory diagram for explaining an energized state at the time of peak current supply, and FIG. 7B is an explanatory diagram for explaining a recovery state to the capacitor C. 8A is a time chart showing a voltage change of the common mode voltage in the pause coil 12a of FIG. 6, and FIG. 8B is a time chart showing a voltage change of the common mode voltage in the drive coil 11a of FIG. It is a chart.

  As shown in FIG. 6, the solenoid valve drive device 20c according to the fourth embodiment includes a current detection resistor R1 instead of the switches 22a and 22b, the diode D2, and the switch 23 described in the first embodiment. A switch 22 provided in series between the other end and the output terminals P2 and P4, a diode D2a having an anode connected to the ground line and a cathode connected to the output terminal P1, and an anode connected to the ground line and a cathode A diode D2b connected to the output terminal P3; a switch 23a for connecting the positive side of the capacitor C to the output terminal P1; and a switch 23b for connecting the positive side of the capacitor C to the output terminal P3. Yes.

  Here, the switch 22 functions as a switch means that can share the low potential sides of the coils 11a and 12a of the electromagnetic valves 11 and 12 so that they can be grounded, and either one of the electromagnetic valves 11 and 12 is open. In this case, the low potential sides of the coils 11a and 12a of both the solenoid valves 11 and 12 are all grounded.

  An energy recovery path for recovering flyback energy from the coils 11a and 12a to the capacitor C is provided between the output terminals P2 and P4 and the positive side of the capacitor C, and this energy recovery path. Above, a diode D3 for current direction control is provided with the cathode as the capacitor C side.

Next, the operation of the electromagnetic valve drive device 20c configured as described above will be described below.
First, the control circuit 21 sets a drive period in which the coils 11a and 12a of the electromagnetic valves 11 and 12 should be energized for each cylinder based on engine operation information such as the engine speed and the accelerator opening, and the coil 11a. The switch 22 is turned on only during the drive period in which the current is to be supplied.

  The control circuit 21 turns on the switch corresponding to the solenoid valve at the start timing of the drive period of any solenoid valve, and turns on the switch 22 at the same time. For example, at the start timing of the drive period of the electromagnetic valve 11, the switch 22 is turned on, and at the same time, the switch 23a is turned on.

  For this reason, when the positive side of the capacitor C is connected to the output terminal P1 via the switch 23a, the energy charged in the capacitor C is released to the coil 11a, and the high voltage of the capacitor C is applied to the coil 11a. (See arrow α3 in FIG. 7A). At this time, a large current, that is, a peak current, flows through the coil 11a due to the discharge of the capacitor C so that the solenoid valve 11 is promptly shifted to the valve open state.

  When such a capacitor C is discharged, the wraparound from the output terminal P1 side to the power supply line side, which becomes a high potential, is prevented by the diode D2a. Furthermore, even when the switch 22 is turned on, the diode D3 prevents a current from flowing directly from the positive electrode side of the capacitor C to the switch 22 via the energy recovery path.

  Then, after the switch 23a is turned on, the control circuit 21 detects the coil current flowing through the coil 11a based on the voltage generated in the resistor R1, and turns off the switch 23a when the coil current reaches the target current value Ip of the peak current. . In addition, the switch 23a may be configured to be turned on for a predetermined time without detecting the coil current flowing through the coil 11a.

  In this way, at the start of the drive period of the solenoid valve 11, the switch 23a is turned on, and the accumulated energy of the capacitor C is released to the coil 11a, whereby a peak current flows through the coil 11a, and the solenoid valve 11 The valve opening response becomes faster.

  Then, after the switch 23a is turned off, the control circuit 21 switches the switch 23a so that the coil current detected by the voltage generated in the resistor R1 becomes a constant current Ih smaller than the target current value of the peak current. (ON / OFF control) is started. After the coil current reaches the target current value Ip of the peak current, the switch 23a is repeatedly turned on / off, and the average value of the coil current is controlled to the hold current.

  During constant current control by such a switch 23a, the hold current flows to the coil 11a through the switch 23a by the energy stored in the capacitor C and the power supply voltage VB of the DC power supply B, and the hold current causes the solenoid valve 11 to The valve is kept open. That is, the switch 23a is arranged on the high potential side of the coil 11a and is turned on at the start of the driving period, thereby applying a high voltage of the capacitor C and supplying a peak current to the coil 11a. By starting the switching after supply, the power supply voltage of the DC power supply B is applied to function as a switching element that supplies the hold current to the coil 11a.

  The diode D2a functions as a current return diode for returning current from the ground line side to the coil 11a when the switch 23a is turned off while the switch 22 is turned on. Therefore, when the switch 23a is turned off during the on / off control of the switch 23a, the current flowing through the coil 11a is a current that circulates through the diode D2a.

  After that, when the drive period ends, the control circuit 21 turns off the switch 22 and ends the on / off control (that is, constant current control) of the switch 23a, and also keeps the switch 23a in the off state. Then, energization to the coil 11a is stopped, the electromagnetic valve 11 is closed, and fuel injection by the electromagnetic valve 11 is ended.

  Further, when the switch 22 and the switch 23a are turned off, flyback energy is generated in the coil 11a. The flyback energy is supplied from the output terminal P2 of the coil 11a to the capacitor C through the energy recovery diode D3a. (Refer to arrow α4 in FIG. 7B).

  Thus, after the solenoid valve 11 is closed and the capacitor C is fully charged again, at the start timing of the drive period of the solenoid valve 12, the switch 23b is turned on while the switch 23a is turned off. At the same time, the switch 22 is turned on.

  For this reason, when the positive side of the capacitor C is connected to the output terminal P3 via the switch 23b, the energy charged in the capacitor C is released to the coil 12a, and the high voltage of the capacitor C is applied to the coil 12a. A peak current flows through the coil 12a. Then, after the switch 23b is turned on, the control circuit 21 turns off the switch 23b when the coil current flowing through the coil 12a reaches the target current value of the peak current. In this way, at the start of the drive period of the solenoid valve 12, the switch 23b is turned on, and the accumulated energy of the capacitor C is released to the coil 12a, whereby a peak current flows through the coil 12a, and the solenoid valve 12 The valve opening response becomes faster.

  When the capacitor C is discharged, the wraparound from the output terminal P3 side to the power supply line side, which becomes a high potential, is prevented by the diode D2b.

  Then, the control circuit 21 performs on / off control of the switch 23b so that the coil current detected by the voltage generated in the resistor R1 becomes the hold current after the switch 23b is turned off. 12 is kept open.

  The diode D2b functions as a current return diode for returning current from the ground line side to the coil 12a when the switch 23b is turned off while the switch 22 is turned on. For this reason, when the switch 23b is turned off during the on / off control of the switch 23b, the current flowing through the coil 12a is a current that flows back through the diode D2b.

  After that, when the drive period ends, the control circuit 21 turns off the switch 22 and ends the on / off control (that is, constant current control) of the switch 23b, and also keeps the switch 23b in the off state. Then, energization of the coil 12a is stopped, the electromagnetic valve 12 is closed, and fuel injection by the electromagnetic valve 12 is terminated.

  When the switch 23b and the switch 22 are turned off, flyback energy is generated in the coil 12a. The flyback energy is supplied from the output terminal P4 of the coil 12a to the capacitor C through the energy recovery diode D3. Recovered in the form.

  As described above, in the electromagnetic valve driving device 20c according to the present embodiment, the switches 23a and 23b are arranged on the high potential side of the coils 11a and 12a of the electromagnetic valves 11 and 12 and should be opened. A peak current and a hold current can be supplied to the coil. Even in this case, the configuration for supplying the peak current and the hold current is simplified, and the peak current and the hold current are supplied to a desired coil according to the operation of the switches 23a and 23b arranged on the high potential side of each coil. Can be supplied.

  In the drive period of the electromagnetic valve 11, the switch 22a is not limited to ON / OFF control while the switch 22 is ON, but the switch 22 may be ON / OFF controlled while the switch 23a is ON. Further, in the drive period of the electromagnetic valve 12, the switch 22b may be on / off controlled without being limited to the on / off control of the switch 23b with the switch 22 on.

  Next, the operation and effect of the switch 22 configured to ground all the low potential sides of the coils 11a and 12a will be described below using the conventional solenoid valve driving device 100 shown in FIG. 13 as a comparison target. FIG. 13 is a block diagram showing a schematic configuration of a fuel injection control device that employs a conventional solenoid valve driving device 100. 14A is a time chart showing a voltage change of the common mode voltage in the pause coil 12a of FIG. 13, and FIG. 14B is a time chart showing a voltage change of the common mode voltage in the drive coil 11a of FIG. It is a chart.

  A conventional solenoid valve driving device 100 shown in FIG. 13 is configured to have a switching element 101 (current supply circuit) for holding current supply, etc., for example, with respect to the solenoid valve driving device 20 in the first embodiment. Has been. In this case, on the low potential side of the coils 11a and 12a of both solenoid valves 11 and 12, the low potential side is used as a switch means for applying the voltage from the capacitor C or the DC power source B to the coils 11a and 12a. Switches 110 and 120 for grounding are respectively provided.

  In such a configuration, a predetermined voltage is applied to the coil by closing the switch of the solenoid valve coil (drive coil) to be opened (driving coil) and grounding the low potential side thereof. When this voltage is applied, this predetermined voltage is also applied to the coil (rest coil) of the other solenoid valve, but the switch on the low potential side remains in the open state (off state). At this time, the high potential side and the low potential side of the resting coil have the same potential as the high potential side of the drive coil, and the low potential side of the drive coil becomes the ground potential.

  Therefore, the average voltage of the high potential side voltage and the low potential side voltage in the pause coil, that is, the common mode voltage is larger than the common mode voltage in the drive coil. Since the electromagnetic noise increases as the common mode voltage increases, the electromagnetic noise caused by the common mode voltage of the solenoid valve that is not being driven becomes larger than the electromagnetic noise of the solenoid valve that is being driven.

  For example, since it is the drive period of the electromagnetic valve 11, when the coil 11a is a drive coil and the coil 12a is a pause coil, as shown in FIGS. 14 (A) and 14 (B), the common in the pause coil 12a. The mode voltage (FIG. 14A) is larger than the common mode voltage (FIG. 14B) in the drive coil 11a.

  Therefore, in the present embodiment, when the voltage is applied to the coil (drive coil) of the solenoid valve that should be opened by the switches 23a and 23b arranged on the high potential side, the switch 22 causes the two solenoid valves to be opened. The low potential sides of the coils 11a and 12a of the 11 and 12 are all grounded. For this reason, in a solenoid valve different from the solenoid valve to be opened, the high potential side and the low potential side of the coil (rest coil) are ground potentials.

  For example, since it is the drive period of the solenoid valve 11, when the coil 11a is a drive coil and the coil 12a is a pause coil, the common mode voltage in the pause coil 12a is 0 as shown in FIG. (V), which is smaller than the common mode voltage (FIG. 8B) in the drive coil 11a.

  Here, the effect of reducing the electromagnetic noise described above will be described with reference to FIG. FIG. 9 is a graph for explaining the effect of reducing electromagnetic noise caused by the common mode voltage of the solenoid valve. In FIG. 9, symbol T1 indicates the maximum value in the AM band (510 kHz to 1710 kHz) obtained by frequency analysis of the common mode voltage in the drive coil 11a and the rest coil 12a in the electromagnetic valve drive device 20c according to the present embodiment. Symbol T2 indicates the maximum value in the AM band (510 kHz to 1710 kHz) obtained by frequency analysis of the common mode voltage in the drive coil 11a and the rest coil 12a in the conventional solenoid valve drive device 100.

As shown in FIG. 9, the electromagnetic valve driving device 20c according to the present embodiment (reference numeral T1 in FIG. 9) is lower by about 15 dB than the conventional electromagnetic valve driving apparatus 100 (reference numeral T2 in FIG. 9). I understand that.
Thus, since the high potential side and the low potential side of the resting coil become the ground potential and the common mode voltage becomes low, the influence of electromagnetic noise due to the common mode voltage can be suppressed.

[Fifth Embodiment]
Next, a solenoid valve driving device according to a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 10 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve drive device 20d according to the fifth embodiment.
The electromagnetic valve drive device 20d according to the fifth embodiment is an electromagnetic valve that injects fuel into each cylinder of a four-cylinder engine and does not open simultaneously at the same time as the fourth embodiment. An electromagnetic valve group G composed of 11 to 14 is an object to be driven, and a current supply unit including a capacitor, a DCDC converter (charging unit), and a switch as a set for the electromagnetic valve group G includes the electromagnetic valve. Two groups are provided so that current can be supplied to each group G.

  Specifically, as shown in FIG. 10, the solenoid valve drive device 20d is connected to the high potential side (high side) of the coil 13a of the solenoid valve 13 as an output terminal in addition to the output terminals P1 to P4. The output terminal P5, the output terminal P6 to which the low potential side (low side) of the coil 13a is connected, the output terminal P7 to which the high potential side of the coil 14a of the solenoid valve 14 is connected, and the low potential side of the coil 14a are connected. And an output terminal P8. In addition to the switches 23a and 23b, the solenoid valve driving device 20a includes a switch 23c for connecting the positive side of the capacitor to the output terminal P5, and a switch 23d for connecting the positive side of the capacitor to the output terminal P7. It is equipped with.

  For this reason, the switch 22 functions as a switch means shared so that the low potential sides of the coils 11a to 14a of the electromagnetic valves 11 to 14 can be grounded, and any one of the electromagnetic valves 11 to 14 is open. In this case, all the low potential sides of the coils 11a to 14a of the electromagnetic valves 11 to 14 function to be grounded.

  Further, the electromagnetic valve driving device 20d connects the first capacitor Ca for causing the peak current to flow through the coils 11a to 14a and the positive side of the first capacitor Ca to any one of the output terminals P1, P3, P5, and P7. Switch 25a, a backflow prevention diode D4a disposed between the switch 25a and each output terminal, and a power supply voltage VB of a DC power supply (battery) B that is boosted to a voltage higher than the power supply voltage VB. There is provided a first current supply means 31 having a DCDC converter 24 that generates a voltage and charges the first capacitor Ca by supplying the high voltage to the first capacitor Ca via the diode D1a. Further, the electromagnetic valve driving device 20d connects the second capacitor Cb for causing the peak current to flow through the coils 11a to 14a and the positive side of the second capacitor Cb to any one of the output terminals P1, P3, P5, and P7. Switch 25b, a backflow prevention diode D4b disposed between the switch 25b and each output terminal, and a power supply voltage VB of a DC power supply (battery) B that is boosted to a voltage higher than the power supply voltage VB. A second current supply means 32 having a DCDC converter 24c for generating a voltage and charging the second capacitor Cb by supplying the high voltage to the second capacitor Cb via the diode D1b is provided.

  In the electromagnetic valve drive device 20d configured as described above, the first current supply unit 31 and the second current supply unit 32, which are a set of a capacitor, a DCDC converter (charging unit), and a switch, Since two sets are provided, even if the first capacitor Ca of the first current supply means 31 is in a charged state, the fully charged second capacitor Cb of the second current supply means 32 can be obtained by turning on the switch 25b. Can be used. As described above, when the peak current is supplied from the second capacitor Cb by turning on the switch 25b, the voltage of each output terminal P1, or P3, or P5, or P7 is changed by the diode D4a. Since the voltage of the capacitor Ca is larger than that of the capacitor Ca, current is prevented from flowing through the parasitic diode of the switch 25a. Even when the second capacitor Cb of the second current supply means 32 is in a charged state, the fully charged first capacitor Ca of the first current supply means 31 can be used by turning on the switch 25a. it can. In this way, when the switch 25a is turned on to supply a peak current from the first capacitor Ca, the diode D4b causes the voltage at each output terminal P1, or P3, or P5, or P7 to be the first. Since the voltage is larger than the voltage of the two capacitors Cb, current is prevented from flowing through the parasitic diode of the switch 25b.

  This suppresses the influence of electromagnetic noise caused by the common mode voltage, and shortens the time (interval time) from driving one solenoid valve of the solenoid valve group G to driving another solenoid valve. can do. The solenoid valve group G to be driven by the solenoid valve driving device 20d is not limited to four solenoid valves that are not simultaneously opened, and is composed of three solenoid valves that are not simultaneously open. Alternatively, it may be composed of five or more solenoid valves that do not open simultaneously.

  Note that the current supply means is not limited to two sets that can supply current to the electromagnetic valve group G, but three or more sets may be provided in order to further shorten the interval time.

[Sixth Embodiment]
Next, a solenoid valve driving device according to a sixth embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve drive device 20e according to the sixth embodiment.
The solenoid valve drive device 20e according to the sixth embodiment is different from the fifth embodiment in that the solenoid valve drive device 20e is simultaneously opened with the first solenoid valve group G1 composed of the two solenoid valves 11 and 12 that are not simultaneously opened. The second solenoid valve group G2 composed of the two solenoid valves 13 and 14 that are not in the valve state is configured to be driven. That is, the electromagnetic valve drive device 20e is configured to be able to open simultaneously electromagnetic valves from different groups.

  As shown in FIG. 11, the electromagnetic valve drive device 20e supplies a current to the first electromagnetic valve group G1 and a first current supply means 31a for supplying a current to the first electromagnetic valve group G1. Second current supply means 32a.

  The first current supply means 31a includes capacitors Ca and Cc for causing a peak current to flow through the coils 11a and 12a, a switch 26a for connecting the positive side of the capacitor Ca to one of the output terminals P1 and P3, and a capacitor Cc. A switch 26c for connecting the positive electrode side to either one of the output terminals P1 and P3 and the power supply voltage VB of the DC power supply (battery) B are boosted to generate a high voltage higher than the power supply voltage VB. And a DCDC converter 24 that charges the capacitors Ca and Cc by supplying a voltage to the capacitors Ca and Cc via the diode D1a. That is, two capacitors Ca and Cc are provided for the DCDC converter 24 which is one charging means, and the DCDC converter 24 is configured to be able to charge these two capacitors Ca and Cc.

  Therefore, the switches 23a and 23b are switching elements that can supply a peak current by applying a high voltage of any one of the two capacitors Ca and Cc to the coil of the solenoid valve that should be opened. Will be configured.

  The second current supply means 32a includes capacitors Cb and Cd for causing a peak current to flow through the coils 13a and 14a, a switch 26b for connecting the positive side of the capacitor Cb to any one of the output terminals P5 and P7, A switch 26d for connecting the positive side of the capacitor Cd to one of the output terminals P5 and P7, and boosting the power supply voltage VB of the DC power supply (battery) B to generate a high voltage higher than the power supply voltage VB; A DCDC converter 24c that charges the capacitors Cb and Cd by supplying the high voltage to the capacitors Cb and Cd via the diode D1b. That is, two capacitors Cb and Cd are provided for the DCDC converter 24c which is one charging means, and the DCDC converter 24c is configured to be able to charge these two capacitors Cb and Cd.

  Therefore, the switches 23c and 23d are switching elements that can supply a peak current by applying a high voltage of one of the two capacitors Cb and Cd to the coil of the solenoid valve to be opened. Will be configured.

  In the solenoid valve drive device 20d, a switch 22e is provided in series between the other end of the current detection resistor R1a and the output terminals P2 and P4, and the other end of the current detection resistor R1b and the output terminals P6 and P8 are connected. A switch 22f is provided in series. For this reason, the switch 22e functions as a switch means shared so that the low potential sides of the coils 11a and 12a of the electromagnetic valves 11 and 12 can be grounded, and either one of the electromagnetic valves 11 and 12 is open. In this case, the low potential sides of the coils 11a and 12a of both the solenoid valves 11 and 12 are all grounded. Further, the switch 22f functions as a switch means that is shared so that the low potential sides of the coils 13a and 14a of the electromagnetic valves 13 and 14 can be grounded, respectively, and one of the electromagnetic valves 13 and 14 is in an open state. In this case, all of the low potential sides of the coils 13a and 14a of the electromagnetic valves 13 and 14 are grounded. Thereby, the influence of the electromagnetic noise resulting from a common mode voltage can be suppressed similarly to the said 4th Embodiment.

  An energy recovery path for recovering flyback energy from the coils 11a and 12a to the capacitor Cc is provided between the output terminals P2 and P4 and the positive side of the capacitor Cc. Above, a diode D3a for current direction control is provided with the cathode on the capacitor Cc side. Similarly, an energy recovery path for recovering flyback energy from the coils 13a and 14a to the capacitor Cd is provided between the output terminals P6 and P8 and the positive side of the capacitor Cd. On the use path, a diode D3b for current direction control is provided with the cathode on the capacitor Cd side.

  In the electromagnetic valve drive device 20e configured as described above, when supplying a peak current to the coil of any one of the electromagnetic valves in the first electromagnetic valve group G1, the capacitor Ca and the capacitor Cc are fully charged. When the positive side switches (26a, 26c) are turned on, the peak current is supplied to the coil of the solenoid valve to be opened, and then the hold current is supplied. Further, when supplying a peak current to the coil of one of the solenoid valves in the second solenoid valve group G2, the switches (26b, 26d) on the positive side of the fully charged capacitor among the capacitors Cb and Cd are turned on. By entering the state, the peak current is supplied to the coil of the solenoid valve to be opened, and then the hold current is supplied.

  Thus, in the solenoid valve drive device 20e according to the present embodiment, the solenoid valves of different groups (groups), for example, the solenoid valve 11 of the first solenoid valve group G1 and the solenoid valve 13 of the second solenoid valve group G2 are provided. At the same time, the drive can be controlled so that the valve can be opened.

  In particular, since the first current supply means 31a is provided with two capacitors Ca and Cc for the DCDC converter 24, the control circuit 21 controls the switches 26a and 26c so that one capacitor is in a charged state. Also other fully charged capacitors can be used. Thereby, after driving one solenoid valve (for example, solenoid valve 11) of the 1st solenoid valve group G1, time until it drives another solenoid valve (for example, solenoid valve 12) can be shortened. it can.

  Similarly, since the second current supply means 32a is provided with two capacitors Cb and Cd for the DCDC converter 24c, the control circuit 21 controls the switches 26b and 26d so that one capacitor is in a charged state. However, other fully charged capacitors can be used. Thereby, after driving one solenoid valve (for example, solenoid valve 13) of the 2nd solenoid valve group G2, time until it drives another solenoid valve (for example, solenoid valve 14) can be shortened. it can.

  The electromagnetic valve driving device 20e is not limited to driving the two electromagnetic valve groups of the first electromagnetic valve group G1 and the second electromagnetic valve group G2, and may drive three or more electromagnetic valve groups. Good. Each solenoid valve group is not limited to two solenoid valves that are not simultaneously opened, and may be composed of three or more solenoid valves that are not simultaneously open.

[Seventh Embodiment]
Next, a solenoid valve driving device according to a seventh embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a block diagram showing a schematic configuration of the fuel injection control device 10 employing the electromagnetic valve drive device 20f according to the seventh embodiment.
The electromagnetic valve drive device 20f according to the seventh embodiment employs the current supply means 31 and 32 described above instead of the current supply means 31a and 32a as compared with the sixth embodiment, and supplies these two currents. Each of the means 31 and 32 is configured to be able to use either the same set of capacitors or another set of capacitors.

  Specifically, as shown in FIG. 12, the electromagnetic valve driving device 20f includes a switch 25a for connecting the positive side of the first capacitor Ca to one of the output terminals P1 and P3, A backflow prevention diode D4a disposed between the output terminal, a switch 25b for connecting the positive side of the second capacitor Cb to one of the output terminals P5 and P7, the switch 25b and each output terminal And a backflow preventing diode D4b disposed between the two. The switch 27a connects the capacitor side of the switch 25a and the coil side of the switch 25b so as to be energized, the backflow prevention diode D5a disposed between the switch 27a and the coil side of the switch 25b, and the switch 25a. A switch 27b that connects the coil side of the switch 25b and the capacitor side of the switch 25b so as to be energized, and a backflow prevention diode D5b disposed between the switch 27b and the coil side of the switch 25a are provided.

  As a result, when the solenoid valve 11 and the solenoid valve 12 of the first solenoid valve group G1 are continuously driven and controlled, the switches 27a and 27b are turned off and the peak current and the hold current are supplied to the coil 11a. Thus, by controlling the switches 22e, 23a, 23b, etc., drive control of the electromagnetic valve 11 using the first capacitor Ca is performed. After the drive period of the solenoid valve 11, the switch 27b is turned on so that the high voltage of the second capacitor Cb can be applied to the first solenoid valve group G1, and the peak current and hold are applied to the coil 12a. By controlling the switches 22e, 23a, 23b and the like so as to supply current, drive control of the electromagnetic valve 12 using the second capacitor Cb is performed. Thus, when the peak current is supplied from the second capacitor Cb because the switch 27b is turned on, the voltage of each output terminal P1 or P3 is set by the diode D4a from the voltage of the first capacitor Ca. Since it is large, current is prevented from flowing through the parasitic diode of the switch 25a. Further, when the peak current is supplied from the second capacitor Cb by turning on the switch 25b, the voltage of each output terminal P5 or P7 is larger than the voltage of the first capacitor Ca by the diode D5b. Current is prevented from flowing through the parasitic diode of the switch 27b.

  Thus, the solenoid valve drive device 20f applies either the high voltage of the same set of capacitors or the high voltage of the other set of capacitors to the coil of the solenoid valve to be opened. It is configured to be able to supply peak current. As a result, even if the same set of capacitors is in a charged state, another set of fully charged capacitors can be used. Therefore, after driving one solenoid valve of the solenoid valve group, another solenoid valve is used. It is possible to shorten the time (interval time) until the is driven.

  The electromagnetic valve driving device 20f is not limited to driving the two electromagnetic valve groups of the first electromagnetic valve group G1 and the second electromagnetic valve group G2, and may drive three or more electromagnetic valve groups. Good. Each solenoid valve group is not limited to two solenoid valves that are not simultaneously opened, and may be composed of three or more solenoid valves that are not simultaneously open.

In addition, this invention is not limited to said each embodiment, You may actualize as follows.
(1) The solenoid valve driving device according to the present invention is limited to a solenoid valve that supplies fuel to each cylinder of a two-cylinder engine and an electromagnetic valve that supplies fuel to each cylinder of a four-cylinder engine. For example, a solenoid valve for a three-cylinder engine may be the control target, or a solenoid valve for a multi-cylinder engine having five or more cylinders may be the control target. Examples of the engine having two or more cylinders include a gasoline engine and a diesel engine.

(2) Of the switches described above, a switch that is not subjected to switching control is not limited to a switching element such as a MOSFET, but may be a switch unit that can be controlled on / off.

(3) The energy recovery diode provided on the above-described energy recovery path may be omitted depending on the use situation.

DESCRIPTION OF SYMBOLS 10 ... Fuel-injection control apparatus 11-14 ... Solenoid valve 11a-14a ... Coil 20, 20a-20f ... Solenoid valve drive device 24, 24c ... DCDC converter (charging means)
22, 22a-22f ... switch 23, 23a-23d ... switch C, Ca-Cd ... capacitor G, G1, G2 ... solenoid valve group

Claims (8)

A peak current for quickly opening the solenoid valve at the start of a set drive period with respect to the coil of the solenoid valve, and for maintaining the valve open state until the drive period ends An electromagnetic valve driving device for supplying a hold current smaller than the peak current,
A capacitor capable of supplying the peak current to the coil;
Charging means for charging the capacitor by generating a high voltage higher than a power supply voltage from a DC power supply,
The capacitor is connected in parallel to the power supply path from the DC power supply to the coil,
Arranged on either the high potential side or the low potential side of the coil and turned on at the start of the driving period, applying the high voltage of the capacitor to supply the peak current to the coil, An electromagnetic valve driving device comprising: a switching element that starts switching after supplying the peak current to apply a power supply voltage of the DC power supply and supplies the hold current to the coil.   2. The electromagnetic valve driving device according to claim 1, wherein an electrostatic capacity of the capacitor is set to an upper limit current value at which the peak current can be supplied to the coil. At the same time, a solenoid valve group composed of two or more solenoid valves that are not in the open state is a driving target,
The switching element is disposed on a high potential side of a coil of each solenoid valve constituting the solenoid valve group, and the peak current and the coil of the solenoid valve to be opened in the solenoid valve group The electromagnetic valve drive device according to claim 1, wherein the hold current can be supplied. The switch means is shared so that the low potential side of each solenoid valve coil constituting the solenoid valve group can be grounded,
The switch means grounds all of the low potential sides of the coils of the solenoid valves when any one of the solenoid valves constituting the solenoid valve group is in the open state. 3. The electromagnetic valve driving device according to 3. At the same time, a solenoid valve group composed of two or more solenoid valves that are not in the open state is a driving target,
The switching element is disposed on a low potential side of a coil of each solenoid valve that constitutes the solenoid valve group, and the peak current and the coil of the solenoid valve to be opened in the solenoid valve group The electromagnetic valve drive device according to claim 1, wherein the hold current can be supplied.   6. The electromagnetic according to claim 3, wherein a plurality of sets of current supply means including the capacitor, the charging unit, and the switching element are provided for the electromagnetic valve group. Valve drive device. A plurality of capacitors for one charging means;
The charging means is configured to be able to charge the plurality of capacitors,
The switching element is configured to be able to supply the peak current by applying a high voltage of any one of the plurality of capacitors to the coil of the solenoid valve to be opened. The electromagnetic valve drive device according to any one of claims 3 to 5. A plurality of the electromagnetic valve groups are to be driven, and for each of the electromagnetic valve groups, a current supply unit that includes the capacitor, the charging unit, and the switching element as a set is provided.
The switching element of the current supply means applies either a high voltage of the capacitor in the same set or a high voltage of the capacitor in another set to the coil of the solenoid valve to be opened. The electromagnetic valve driving device according to claim 3, wherein the peak current can be supplied.

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