JP2009024662A - Control device of electromagnetic load - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain a stable drive state, by preventing lowering of a current when a peak current is applied by boosting voltage in the early stages of the drive of an electromagnetic load and then is decreased to a holding current. <P>SOLUTION: A control device has the electromagnetic load, a power source, a control circuit and a switch means. The control device increases a drive current of the electromagnetic load to a predetermined peak current set value by the voltage of the power source, and operates the switch means to reduce the drive current when it reaches the peak current set value. One or a plurality of stages of sequentially lowered current set values are defined in the course of reducing the drive current. In the control device, when it is reduced from a certain current set value to the next current set value, the control device controls to sharply decrease the current set value at first, and then to gently decrease the current set value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic load control device for maintaining a stable operating state of an injector used for fuel supply of an internal combustion engine, for example.

  2. Description of the Related Art Conventionally, in an electromagnetic load control device, a method is known in which a large current is supplied in the initial stage of driving and a constant current (holding current) is supplied after the initial period has elapsed in order to maintain the electromagnetic load in a stable state. .

  For example, Patent Document 1 discloses a technique for controlling so that a current does not drop to a value smaller than the holding current when the current is reduced to the holding current after flowing a large current in the initial stage of driving.

JP 59-103091 A

  The technique disclosed in Patent Document 1 drives an electromagnetic load by a battery voltage mounted on an internal combustion engine, and has a problem that a current flowing at an early stage of driving is small and a current response is slow. This means that for the driving current of the electromagnetic load, the decrease from the large current at the initial driving to the holding current becomes gradual, and the drop below the holding current is small.

  Accordingly, an object of the present invention is to provide an electromagnetic load control device in which the response of the current in the initial stage of the drive is fast while preventing a drop below the holding current.

  In order to solve the above problems, an electromagnetic load control device of the present invention includes an electromagnetic load, a power source, a control circuit, and a switch means, and the driving current of the electromagnetic load has a predetermined peak by the voltage of the power source. In the control device that increases the current setting value to reach the peak current setting value and operates the switch means to decrease the driving current when the peak current setting value is reached, the control device sequentially decreases one or more stages during the process of decreasing the driving current. A current set value is provided, and when the current set value is decreased from one current set value to the next current set value, control is performed such that the current is first decreased with a steep slope and then decreased with a gentle slope.

  In addition, the electromagnetic load control device of the present invention includes an electromagnetic load, a power source, a booster circuit, a control circuit, and switch means, and the drive current of the electromagnetic load is set to a predetermined peak by the boosted voltage of the booster circuit. In the control device that increases the current set value to reach the peak current set value and reduces the drive current using a switch means and a diode when the peak current set value is reached, the controller is connected in series between the booster circuit and one terminal of the electromagnetic load. First current detecting means, first switch means, second switch means connected between the power source and the terminal of the electromagnetic load, and sequentially connected in series to the other terminal of the electromagnetic load. Third switch means and second current detecting means, feedback means for feeding back the back electromotive force energy of the electromagnetic load to the booster circuit, and a circulation means for circulating back electromotive force energy of the electromagnetic load. And the first and third switch means are turned on when driving the electromagnetic load, and the detection value of the first or second current detection means reaches the first set value. Then, when the first and third switch means are turned off and the feedback means is energized, and the detection value of the first current detection means reaches a predetermined threshold value, the third switch means Is turned on to energize the circulating means, and when the detection value of the second current detecting means reaches the lower limit of the second set value, the second switch means is turned on and energized from the power source. And when the detected value of the second current detecting means reaches the upper limit of the second set value, the second switch means is repeatedly turned off to repeat the second setting. When the signal to end the maintenance of the value is received, the current falls to the lower limit of the second set value. Without turning on the second switch means also when, is characterized in reducing the current.

  In addition, the electromagnetic load control device of the present invention includes an electromagnetic load, a power source, a booster circuit, a control circuit, and a switch means. In the control device that increases the current set value to reach the peak current set value and reduces the drive current using a switch means and a diode when the peak current set value is reached, the controller is connected in series between the booster circuit and one terminal of the electromagnetic load First current detecting means, first switch means, second switch means connected between the power source and the terminal of the electromagnetic load, and sequentially connected in series to the other terminal of the electromagnetic load. Third switch means and second current detecting means, feedback means for feeding back the back electromotive force energy of the electromagnetic load to the booster circuit, and a circulation means for circulating back electromotive force energy of the electromagnetic load. And the first and third switch means are turned on when driving the electromagnetic load, and the detection value of the first or second current detection means reaches the first set value. Then, the third switch is turned off when a predetermined time elapses after the first and third switch means are turned off, the feedback means is energized, and the first and third switch means are turned off. When the detection value of the second current detection means reaches the lower limit of the second set value, the second switch means is turned on and the power supply is energized. And when the detected value of the second current detecting means reaches the upper limit of the second set value, the second switch means is repeatedly turned off to repeat the second setting. When the signal to end the maintenance of the value is received, the current becomes the second set value. Without turning on the second switching means even when reaching the limit, and is characterized in reducing the current.

  In addition to the above feature, the electromagnetic load control device of the present invention is provided with a third setting value or a plurality of sequentially decreasing setting values when reducing the current from the second setting value, Each of the currents is characterized in that the current decrease is switched from a steep slope to a gentle slope when a predetermined threshold value or a predetermined time elapses.

  In addition to the above features, the electromagnetic load control device of the present invention is characterized in that the feedback means and the circulation means are diodes.

  Further, the electromagnetic load control device of the present invention includes an electromagnetic load, a power source, a booster circuit, a control circuit, and a switch means, and the drive current of the electromagnetic load is set to a predetermined peak by the boosted voltage of the booster circuit. In the control device that increases the current set value to reach the peak current set value and reduces the drive current using a switch means and a diode when the peak current set value is reached, the controller is connected in series between the booster circuit and one terminal of the electromagnetic load. A first switch means, a second switch means connected between the power source and the terminal of the electromagnetic load, and a third switch means and a first switch connected to the other terminal of the electromagnetic load. A line in which the current detection means is sequentially connected and a line in which the constant voltage diode and the second current detection means are sequentially connected are connected in parallel, and from the downstream side of the terminals of the first and second current detection means. The electromagnetic A diode is connected toward the upstream side of the load, and when the electromagnetic load starts to be driven, the first and third switch means are turned on, and the detection value of the first current detection means is a first set value. , The first and third switch means are turned off, the constant voltage diode and the diode are energized to feed back current, and the detection value of the second current detection means is a predetermined threshold value. Or after a predetermined time has passed since turning off the first and third switch means, turning on the third switch means, energizing the diode, circulating current, When the detection value of the first current detection means reaches the lower limit of the second set value, the second switch means is turned on, the current is supplied from the power source to increase the current, and the first current The detection value of the detection means is the second set value When the limit is reached, the operation of turning off the third switch means is repeated, and when the signal for ending the maintenance of the second set value is received, the current also reaches the lower limit of the second set value. The current is reduced without turning on the second switch means.

  The electromagnetic load control device according to the present invention includes first and second electromagnetic loads, a power source, a booster circuit, a control circuit, and a switch means, and the electromagnetic load is controlled by the boosted voltage of the booster circuit. In the control device that increases the drive current to a predetermined peak current set value and reduces the drive current using the switch means and the diode when the peak current set value is reached, the booster circuit and the first and second electromagnetics First current detection means and first switch means connected in series between one terminal of the load, and second switch means connected between the power source and the terminal of each electromagnetic load And third switch means and second current detection means are sequentially connected to the other terminal of the first electromagnetic load, and fourth switch means is connected to the other terminal of the second electromagnetic load. And the third current detection means are connected in sequence. A diode is connected from the downstream side of the second and third current detection means toward the upstream side of the first and second electromagnetic loads, and the downstream side of the first electromagnetic load and the first Diodes are connected from the downstream side of the second electromagnetic load to the downstream side of the first current detection means and the upstream side of the first switch means, and the driving of the first electromagnetic load is started. Sometimes the first and third switch means are turned on, and when the detection value of the first or second current detection means reaches a first set value, the first and third switch means are turned on. When the detection value of the first current detection means reaches a predetermined threshold value, or when the first and third switch means are turned off. After a predetermined time has elapsed, the third switch means is Is turned on, the current is circulated by energizing the diode, and when the detection value of the second current detection means reaches the lower limit of the second set value, the second switch means is turned on, and the power supply The second switch means is repeatedly turned off when the detected value of the second current detecting means reaches the upper limit of the second set value, and the second switch means is turned off. When the signal to end the maintenance of the set value of 2 is received, the second switch means is not turned on even when the current reaches the lower limit of the second set value, and the current is decreased. When driving the second electromagnetic load, the first and fourth switch means are turned on, and when the detection value of the first or third current detection means reaches a first set value, 1 and the fourth switch means are turned off to A current is fed back by energizing a diode, and when a detection value of the first current detection means reaches a predetermined threshold value or a predetermined time has passed since the first and fourth switch means were turned off. Thereafter, when the fourth switch means is turned on, the diode is energized to circulate the current, and when the detection value of the third current detection means reaches the lower limit of the second set value, And when the detection value of the third current detection means reaches the upper limit of the second set value, the second switch means is turned on. When a signal for ending the maintenance of the second set value is received after repeating the operation of turning off, the second switch means is not turned on even when the current reaches the lower limit of the second set value. The process of decreasing the And it is characterized in Succoth.

  According to the electromagnetic load control device of the present invention, when the current is decreased from a large current at the initial stage of driving to a holding current, the current is decreased with a steep slope at first and then with a gentle slope, so that the response speed is not greatly impaired. This has the effect of preventing a drop below the holding current.

  Therefore, for example, when applied to a fuel injection solenoid valve for an internal combustion engine, fuel control can be performed with high accuracy.

  The best mode for carrying out the present invention will be described below with reference to some examples.

[Example 1]
Example 1 is an example in which the present invention is applied to an injector for fuel injection in an automobile engine system.
FIG. 1 shows a circuit configuration of an injector control device according to the first embodiment. The automobile engine system is multi-cylinder and includes a plurality of injectors. In FIG. 1, only one injector 10 is shown as a representative. The injector 10 is supplied with the voltage of the battery 20 and the voltage 36 boosted from the battery 20 by the booster circuit 30, and the current is controlled by these voltages.

  The booster circuit 30 turns on the transistor 32 and causes a current to flow through the coil 31. When the transistor 32 is turned off, the back electromotive force energy of the coil 31 is accumulated in the capacitor 35, and the boosted voltage 36 is obtained. The diode 34 prevents the boosted voltage 36 from being short-circuited when the transistor 32 is turned on. The control circuit 37 detects the boosted voltage 36 and performs on / off control of the transistor 32 by the control signal 33 so that the boosted voltage 36 becomes a predetermined voltage value.

  Next, circuit connection to the injector 10 will be described. The current detection resistor 160 for detecting the current flowing through the booster circuit 30 and the transistor 100 are connected to one terminal of the injector 10, and the other terminal of the injector 10 has a current detection for detecting the current flowing through the transistor 110 and the injector 10. A resistor 170 is connected. Furthermore, a diode 140 that feeds back the back electromotive force energy of the injector 10 back to the booster circuit 30 is connected to the other terminal of the injector 10.

  When both ends of the battery 20 are viewed, the transistor 120 and the backflow element diode 130 to the battery 20 are connected to one terminal of the injector 10, and the diode 150 that circulates the back electromotive force energy of the injector 10 is connected to the other terminal. Yes.

  The drive signal lines of the transistors 100, 110, and 120 and the detection voltage lines of the current detection resistors 160 and 170 are connected to the control circuit 40.

  FIG. 2 shows the injector current waveform and transistor operation of the first embodiment shown in FIG. Here, the peak of the injector current 11 at the time point t1 is referred to as a peak current ip, and the constant injector current 11 at the time t2 to t3 is referred to as a holding current ih.

  When the transistors 100 and 110 are turned on at the time t0 in the initial driving of the injector 10, the currents 12 and 13 become currents that rise up to the time t1 due to the application of the boost voltage 36. Due to the electromagnetic force of the injector 10 generated by this current, an injection valve (not shown) is opened, and fuel injection into the engine cylinder is started. The peak current ip flowing through the injector 10 is detected by the voltage drop of the current detection resistor 170 caused by the current 13 flowing. This peak current ip is set to a value such that the injection valve is almost open.

  When the current 13 reaches the peak current ip (time t1), the transistors 100 and 110 are turned off. As a result, the diodes 140 and 150 are energized by the back electromotive force energy of the injector 10, and the currents 14 and 15 are fed back to the booster circuit 30, while the injector current decreases from the peak current ip. The currents 14 and 15 act on the charge of the capacitor 35 of the booster circuit 30 and supplement the decrease in the voltage 36 due to the electric charge consumed in the period of time t0 to t1.

  The feedback current 14 is detected by the current detection resistor 160, and at time t11 when this value reaches the threshold value is1, the transistor 110 is turned on. Then, the current due to the back electromotive force energy of the injector 10 is switched from the feedback currents 14 and 15 to the circulating currents 13 and 15. The slope of the current drop during the period from time t1 to t11 becomes steep due to the boost voltage 36 that hinders the flow of the feedback currents 14 and 15, but after time t11, the voltage that hinders the flow of the circulating currents 13 and 15 As a result, the current drop has a gentler slope than that of the feedback currents 14 and 15.

  The circulating currents 13 and 15 are detected by the current detection resistor 170, and when the lower limit value ihl1 of the holding current ih is reached, the transistor 120 is turned on. At this time, since the transistor 110 is in the on state, when the transistor 120 is turned on, the voltage of the battery 20 is applied to the injector 10, currents 16 and 13 flow, and the current increases from the time t2. When the upper limit value ihh1 of the holding current ih1 is reached, the transistor 120 is turned off, and the circulating currents 13 and 15 are caused to flow by the back electromotive force energy of the injector 10, thereby reducing the injector current again. In the period of time t2 to t3, the holding current ih1 is controlled to be a predetermined value by repeating this operation, that is, by repeating the ON / OFF operation of the transistor 120.

  The time interval t1 to t2 is a period during which soft landing is performed from the state where the injection valve is almost opened to the complete valve opening state, and the period from time t2 to t3 is a period during which the complete valve opening is maintained. In an engine control logic circuit (not shown), the valve opening time of the injector 10 is set according to the engine speed, the temperature of the cooling water, the amount of air, etc., and an injection pulse 50 corresponding to the valve opening time is input to the control circuit 40. Is done. The period of time t0 to t3 corresponds to the time of the injection pulse 50.

  FIG. 3 shows an internal circuit configuration of the control circuit 40 according to the first embodiment, and shows a current detection circuit 41 of the detection resistor 160 through which the feedback current 14 flows, and an ON signal generation circuit 42 of the transistor 110.

  By the way, if the period of time t11 to t2 in which the current shown in FIG. 2 decreases with a gentle slope is not provided, that is, if the transistor 110 is turned off during this period, the current drop described in the prior art occurs. The reason for this will be described with reference to FIG.

  A voltage drop generated in the current detection resistor 160 by the current 14 is amplified by the amplifier 411. At this time, capacitors 412 and 413 are connected to the input terminals so that the amplifier 411 does not operate unstablely due to noise. The output voltage of the amplifier 411 is input to the comparator 421 and compared with a reference value obtained by dividing the stabilized voltage 420. When the output voltage of the amplifier 411 is larger than the reference value, the comparator 421 operates to turn off the transistor 110, and turn it on when it is smaller. In order to stabilize the operation of the comparator 421, a capacitor 422 is connected to the input terminal.

  In the above circuit configuration, there is a time delay from the detection of the current 14 until the drive signal for the transistor 110 is generated. Further, the transistor 110 also has a time delay until it is reliably turned on after receiving the drive signal. If the steep currents 14 and 15 continue to drop to the lower limit value ihl1 of the holding current ih due to this time delay, the transistor 110 is turned on when the current is lowered to a value smaller than the lower limit value ihl1, so that the initial value of the holding current ih is increased. Current drops.

  For the above reason, as shown in FIG. 2, before the injector current drops steeply due to the generation of the feedback currents 14 and 15 and reaches the lower limit value ihl1 of the holding current ih1, it is switched to the circulating currents 13 and 15. Thus, the gradient of the injector current is controlled gently. By doing this, the current change over time is made moderate so that the current detection delay due to the time delay of the capacitors 412, 413, and 422 can be ignored, the current drop is eliminated, and the predetermined holding current ih1 is controlled. Can do.

  FIG. 4 is a flowchart showing the operation of the transistors 100, 110, 120 during the period in which the injection pulse 50 is input (period t0 to t3 in FIG. 2).

  In step 500, when the injection pulse 50 is input, in steps 501, the transistors 100 and 110 are turned on, and the current 11 flows through the injector 10.

  In step 502, the current 13 detected by the current detection resistor 170 is compared with the peak current ip. When the current 13 is smaller than the peak current ip, the determination result is NO and the transistors 100 and 110 are kept on. On the other hand, when the current 13 is equal to or larger than the peak current ip, the determination result is YES and the process proceeds to the next step 503.

  In step 503, the transistors 100 and 110 are turned off, the feedback currents 14 and 15 are generated, and the injector current 11 is decreased.

  In step 504, the feedback current 14 detected by the current detection resistor 160 is compared with the threshold value is1. When the feedback current 14 is larger than the threshold value is1, the determination result is NO, and the transistors 100 and 110 are kept off. On the other hand, when the feedback current 14 is equal to or smaller than the threshold value is1, the determination result is YES and the process proceeds to the next step.

  In step 505, transistor 110 is turned on, circulating currents 13 and 15 are generated, and injector current 11 decreases.

  In step 506, the circulating current 13 detected by the current detection resistor 170 is compared with the lower limit value ihl1 of the holding current ih1. When the circulating current 13 is larger than the lower limit value ihl1, the determination result is NO and the transistor 110 is kept on. On the other hand, when it is detected that the circulating current 13 is equal to or smaller than the lower limit value ihl1, the determination result is YES and the process proceeds to the next step.

  In step 507, the transistor 120 is turned on while the transistor 110 remains on, and the injector current 11 increases due to the current 16 from the battery 20.

  In step 508, the current 13 detected by the current detection resistor 170 is compared with the upper limit value ihh1 of the holding current ih1. When the current 13 is smaller than the upper limit value ihh1, the determination result is NO, and the transistors 110 and 120 are kept on. On the other hand, if it is detected that the current 13 is equal to or larger than the upper limit value ihh1, the determination result is YES and the process proceeds to the next step.

  In step 509, the transistor 110 is turned on, the transistor 120 is turned off, the circulating currents 13 and 15 are generated again, and the injector current 11 is decreased.

  Subsequently, steps 505 to 509 are repeated while the injection pulse 50 is being input, and the injector current 11 is controlled to the holding current ih1.

  As described above, according to the first embodiment of the present invention, when the injector current decreases from the peak current ip to the holding current ih1, the injector current decreases steeply to the threshold value is1, and from the threshold value is1. Since it can be controlled so as to decrease gently, there is no effect of current drop, and there is an effect that the valve opening operation of the injector can be stably operated.

  In the first embodiment, the current of the feedback current 14 is detected by the current detection resistor 160, and when this value decreases to the threshold value is1, the transistor 110 is turned on and switched to the circulating currents 13 and 15. As shown in FIG. 2, after the peak current ip is detected, the transistor 110 may be turned on and switched to the circulating currents 13 and 15 after a lapse of a predetermined time T1 from the time t1 when the transistors 100 and 110 were turned off. . During the time during which the injector current 11 decreases from the peak current ip to the threshold value is1 (period from the time point t1 to t11), the boosted voltage 36 is a constant value, or the voltage that decreases with current supply during the period from the time t0 to t1 is a constant value. If so, it becomes almost constant. Therefore, since the time until the threshold value is1 can be known in advance, the transistor 110 can be controlled to be turned on after this time has elapsed.

  In the first embodiment, the current detection of the feedback currents 14 and 15 is detected on the output side of the booster circuit 30 as shown in FIG. 150, the injector 11 and the diode 140 may be connected in series to detect current detection means.

[Example 2]
FIG. 5 shows the current waveform and the operation of the transistor in the injector control apparatus of the second embodiment. Depending on the engine on which the injector is mounted, the specifications of the injector itself and the fuel pressure differ, and the current flowing through the injector must be set to a value that matches them. In the example shown in FIG. 5, the current in the holding period is set in two stages of holding currents ih2 and ih3.

  At time t0, the transistors 100 and 110 are turned on in response to the input of the injection pulse 50, the boost voltage 36 is applied to cause the injector current 11 to flow, and the transistors 100 and 110 are turned off at the peak current value ip. The injector current 11 decreases while being fed back to the booster circuit 30. When the threshold is2 is reached, the transistor 110 is turned on, and the injector current 11 is circulated and decreased with a gentle slope. When the current reaches the lower limit value ihl2 of the first-stage holding current ih2, the transistor 120 is turned on to supply current from the battery 20 to increase the injector current. When the current reaches the upper limit value ihh2 of the first stage holding current ih2, the transistor 120 is turned off, whereby circulating currents 13 and 15 are generated again, and the injector current decreases again. In this way, the ON / OFF operation of the transistor 120 is repeated to hold the transistor 120 at the holding current ih2. The period T2 of the first-stage holding current ih2 is set in advance according to the specifications of the injector 10 to be used.

  When the period T2, which is the duration of the holding current ih2, elapses (at time t21), the transistor 110 is turned off. The injector current 11 decreases while being fed back to the booster circuit 30 again. When the threshold is3 is reached (at time t22), the transistor 110 is turned on to generate the circulating currents 13 and 15, and the current decreases. Decrease the slope. When the current reaches the lower limit value ihl3 (at time t23) of the second-stage holding current ih3, the transistor 120 is turned on to supply current from the battery 20 to increase the current. When the current reaches the upper limit value ihh3 of the second-stage holding current ih3, the transistor 120 is turned off. In this way, the transistor 120 is controlled to be held at the holding current ih3 by repeatedly turning on and off the transistor 120. The above control is continued until the end of the injection pulse 50 (time point t3).

  At the time of transition from the peak current ip to the holding current ih2, and from the holding current ih2 to the holding current ih3, the current reduction slope is controlled gently until the lower limit values ihl2 and ihl3 are reached, so that the injector current 11 does not drop. Although FIG. 5 shows the case where the holding current is controlled to two stages, the holding current is not limited to two stages, and the number of stages may be increased.

  As described above, according to the second embodiment, when the injector current decreases from the peak current ip to the holding current ih2, and when the injector current decreases from the holding current ih2 to the holding current ih3, the injector current is set to the threshold value is2. Or, it is controlled to decrease to a steep slope until is3 and gradually decrease from the threshold value is2 or is3, so that there is no drop in current, and the valve opening operation of the injector can be stably operated. effective.

[Example 3]
FIG. 6 shows a circuit configuration of an injector control device according to the third embodiment. In the third embodiment, a constant voltage diode 180 and a current detection resistor 190 are connected in place of the diode 140 as compared with the first embodiment shown in FIG. Shown with the same reference numerals.

  The operation of the third embodiment will be described below in comparison with the first embodiment. Until the peak current ip is detected, the operation is the same as that of the first embodiment. However, when the peak current ip is detected, the transistors 100 and 110 are turned off. Then, currents 17 and 15 flow in the circuit of the constant voltage diode 180, the detection resistor 190, and the diode 150 due to the back electromotive force energy of the injector 10.

  Since the constant voltage diode 180 maintains a constant voltage, the decrease in the currents 17 and 15 has a steep slope as in the case of feedback to the booster circuit 30. When the value of the current 17 detected by the current detection resistor 190 reaches the threshold value is1, the control circuit 40 turns on the transistor 110. Then, the current due to the back electromotive force energy is switched from the current 17 of the constant voltage diode 180 to the circulating currents 13 and 15, and the current decrease has a gentle slope. The subsequent operation is the same as that of the first embodiment shown in FIG. 1, and the same operation as the injector current 11 shown in FIG. 2 is obtained. Note that the constant voltage diode 180 is set to a voltage value larger than the boost voltage 36 so that no current flows through the injector 10 and the constant voltage diode 180 by the boost voltage 36 when the transistor 110 is off.

  As described above, in the third embodiment, when the injector current is decreased from the peak current ip to the holding current ih1, the constant voltage diode 180 is used to decrease the current sharply, and when the current value reaches the threshold value is1. Since the control is performed so as to decrease gently, there is no effect of current drop, and there is an effect that the valve opening operation of the injector can be stably performed.

[Example 4]
FIG. 7 shows a circuit configuration of an injector control device according to the fourth embodiment. In the fourth embodiment, the same components as those in the first embodiment shown in FIG.
Although an engine is generally composed of a plurality of cylinders, it is not economically advantageous to mount the circuit configuration shown in FIG. 1 for each injector of each cylinder. In the study by the inventors, for example, in a four-cylinder engine, the booster circuit 30 is common to all the cylinder injectors, and the common circuit is used for each of the opposed two-cylinder injectors 1, 3, and 2, and 4 cylinders. It has been clarified that there is no problem in the configuration in terms of circuit interference and injector injection performance. Example 4 reflects this result, and FIG. 7 shows the configuration of a common circuit for driving the injectors 10 and 60 of 1, 2 and 2 opposed cylinders in a 4-cylinder engine.

  The common circuit portion for two cylinders applies a booster circuit 30 (common to other two cylinders not shown), a transistor 100 for applying a boost voltage connected to a common terminal of the injectors 10 and 60, and a battery voltage. A transistor 120, a reverse current element diode 130, a diode 150 for flowing a feedback current and a circulating current, and a feedback current detection resistor 160.

  The single circuit portion for one cylinder includes transistors 110 and 111, current detection resistors 170 and 171 and feedback diodes 140 and 141 connected to the other terminals of the injectors 10 and 60.

  An injection pulse 50 corresponding to the injector 10 and an injection pulse 51 corresponding to the injector 60 are input to the control circuit 40, and the control circuit 40 includes a drive signal line applied to the transistors 110 and 111, a current detection resistor 170, and the like. Input lines from 171 are independent of each other.

  Since the injection pulses 50 and 51 of the first and third cylinders do not overlap, the injector current shown in FIG. 2 flows through the injectors 10 and 60 at time intervals corresponding to the engine speed. At this time, the transistor 110 and the transistor 111 operate alternately.

  When the peak current ip is detected by the current detection resistor 170 when the transistor 110 is on and by the current detection resistor 171 when the transistor 111 is on, the transistor 110 or 111 is turned off. When the transistor 110 is turned off, the diodes 140 and 150 are energized. When the transistor 111 is turned off, the diodes 141 and 150 are energized, and the current due to the back electromotive force energy of the injector is fed back to the booster circuit 30. It decreases with a steep slope.

  The feedback current is detected by the current detection resistor 160, and turns on the transistor 110 or 111 when the current decreases to the threshold value is1. Then, the back electromotive force energy of the injector shifts from the transistor 110 or 111 to the circulating current flowing through the diode 150, and the injector current decreases with a gentle slope. When the current reaches the lower limit value ihl1 of the holding current ih1, the transistor 120 is turned on, current is supplied from the battery, and the injector current is inverted. Hereinafter, the holding current ih1 is set to a constant value by the on / off operation of the transistor 120.

  As described above, in the fourth embodiment of the present invention, even when a part of the circuit of the opposed two cylinders is a common circuit, when each injector current is reduced from the peak current ip to the holding current ih1, Since no depression occurs, there is an effect that the valve opening operation of the injector can be stably operated.

The circuit structure of the control apparatus of the injector of Example 1 of this invention is shown. The current waveform of the injector and the operation of the transistor in Example 1 of the present invention are shown. 1 shows an internal circuit configuration of a control circuit according to a first embodiment of the present invention. It is a flowchart which shows the operation | movement in the time interval t0-t3 of Example 1 of this invention. The current waveform of the injector control apparatus of Example 2 of this invention and the operation | movement of a transistor are shown. The circuit structure of the control apparatus of the injector of Example 3 of this invention is shown. 9 shows a circuit configuration of an injector control device according to Embodiment 4 of the present invention.

Explanation of symbols

10 ... Injector,
11: Injector current,
14 ... Return current,
20 ... Battery,
30: Booster circuit,
40. Control circuit,
41 ... current detection circuit,
42 ... generating circuit,
50: Injection pulse,
100, 110, 120 ... transistor,
130, 140, 150 ... diodes,
160, 170 ... current detection resistors,
180 ... constant voltage diode,
190 ... current detection resistor,
411 ... an amplifier,
421 ... Comparator

Claims (7)

An electromagnetic load, a power source, a control circuit, and switch means, and the voltage of the power source increases the drive current of the electromagnetic load to a predetermined peak current set value, In a control device that operates to reduce the drive current,
In the course of decreasing the drive current, one or more stages of current setting values that are sequentially decreased are provided, and when decreasing from one current setting value to the next current setting value, the initial setting is a steep decrease. Is a control device for electromagnetic load, which is controlled so as to decrease at a gentle slope. An electromagnetic load, a power supply, a booster circuit, a control circuit, and a switch means, and the boosting voltage of the booster circuit raises the driving current of the electromagnetic load to a predetermined peak current set value, and the peak current set value In a control device that reduces the drive current using switch means and a diode when
First current detecting means and first switch means connected in series between the booster circuit and one terminal of the electromagnetic load, and a first current detecting means connected between the power source and the terminal of the electromagnetic load. Two switch means;
Third switch means and second current detection means sequentially connected in series to the other terminal of the electromagnetic load;
Feedback means for returning back electromotive force energy of the electromagnetic load to the booster circuit, and circulation means for circulating back electromotive force energy of the electromagnetic load;
Turning on the first and third switch means when starting to drive the electromagnetic load;
When the detection value of the first or second current detection means reaches a first set value, the first and third switch means are turned off and the feedback means is energized,
When the detection value of the first current detection means reaches a predetermined threshold value, the third switch means is turned on to energize the circulation means,
When the detection value of the second current detection means reaches the lower limit of the second set value, the second switch means is turned on to increase the current by energizing from the power source, and the second When the detection value of the current detection means reaches the upper limit of the second set value, the operation of turning off the second switch means is repeated,
When receiving a signal to end the maintenance of the second set value, the current is reduced without turning on the second switch means even when the current reaches the lower limit of the second set value. Control device for electromagnetic load. An electromagnetic load, a power supply, a booster circuit, a control circuit, and a switch means, and the boosting voltage of the booster circuit raises the driving current of the electromagnetic load to a predetermined peak current set value, and the peak current set value In a control device that reduces the drive current using switch means and a diode when
First current detecting means and first switch means connected in series between the booster circuit and one terminal of the electromagnetic load, and a first current detecting means connected between the power source and the terminal of the electromagnetic load. Two switch means;
Third switch means and second current detection means sequentially connected in series to the other terminal of the electromagnetic load;
Feedback means for returning back electromotive force energy of the electromagnetic load to the booster circuit, and circulation means for circulating back electromotive force energy of the electromagnetic load;
Turning on the first and third switch means when starting to drive the electromagnetic load;
When the detection value of the first or second current detection means reaches a first set value, the first and third switch means are turned off, and the feedback means is energized,
When a predetermined time has elapsed after turning off the first and third switch means, turn on the third switch means, energize the circulation means,
When the detection value of the second current detection means reaches the lower limit of the second set value, the second switch means is turned on to increase the current by energizing from the power source, and the second When the detection value of the current detection means reaches the upper limit of the second set value, the operation of turning off the second switch means is repeated,
When receiving a signal to end the maintenance of the second set value, the current is reduced without turning on the second switch means even when the current reaches the lower limit of the second set value. Control device for electromagnetic load. In the control device according to claim 2 or 3,
When the current is decreased from the second set value, a third set value or a plurality of sequentially decreasing set values are provided, and when the current exceeds a predetermined threshold value or a predetermined time, the current decrease is abrupt. A control device for an electromagnetic load, wherein the control is switched from a slope to a gentle slope. In the control device according to any one of claims 2 to 4,
The control device for an electromagnetic load, wherein the feedback means and the circulation means are diodes. An electromagnetic load, a power supply, a booster circuit, a control circuit, and a switch means, and the boosting voltage of the booster circuit raises the driving current of the electromagnetic load to a predetermined peak current set value, and the peak current set value In a control device that reduces the drive current using switch means and a diode when
First switch means connected in series between the booster circuit and one terminal of the electromagnetic load; second switch means connected between the power supply and the terminal of the electromagnetic load;
The other terminal of the electromagnetic load has a line in which the third switch means and the first current detection means are sequentially connected, and a line in which the constant voltage diode and the second current detection means are sequentially connected in parallel. Connected,
A diode is connected from the downstream side of the terminals of the first and second current detection means toward the upstream side of the electromagnetic load,
Turning on the first and third switch means when starting to drive the electromagnetic load;
When the detection value of the first current detection means reaches a first set value, the first and third switch means are turned off, and the constant voltage diode and the diode are energized to feed back the current. ,
When the detection value of the second current detection means reaches a predetermined threshold value, or after a predetermined time has elapsed after turning off the first and third switch means, the third switch means is turned on. And circulating the current by energizing the diode,
When the detection value of the first current detection means reaches the lower limit of the second set value, the second switch means is turned on, the current is supplied from the power source to increase the current, and the first When the detection value of the current detection means reaches the upper limit of the second set value, the operation of turning off the third switch means is repeated,
When receiving a signal to end the maintenance of the second set value, the current is reduced without turning on the second switch means even when the current reaches the lower limit of the second set value. Control device for electromagnetic load. The first and second electromagnetic loads, a power source, a booster circuit, a control circuit, and a switch means are provided, and the drive current of the electromagnetic load is increased to a predetermined peak current set value by the boosted voltage of the booster circuit. In the control device for reducing the drive current using the switch means and the diode when the peak current set value is reached,
First current detection means and first switch means connected in series between the booster circuit and one of the terminals of the first and second electromagnetic loads, the power supply, and the terminals of the electromagnetic loads A second switch means connected between
Third switch means and second current detection means are sequentially connected to the other terminal of the first electromagnetic load,
A fourth switch means and a third current detection means are sequentially connected to the other terminal of the second electromagnetic load,
A diode is connected from the downstream side of the second and third current detection means toward the upstream side of the first and second electromagnetic loads,
Diodes are connected from the downstream side of the first electromagnetic load and the downstream side of the second electromagnetic load to the downstream side of the first current detection means and the upstream side of the first switch means, respectively. And
Turning on the first and third switch means when starting to drive the first electromagnetic load;
When the detection value of the first or second current detection means reaches a first set value, the first and third switch means are turned off, and the feedback diode is energized to feed back the current. ,
When the detection value of the first current detection means reaches a predetermined threshold value or after a predetermined time has passed since the first and third switch means are turned off, the third switch means is turned on. And circulating the current by energizing the diode,
When the detection value of the second current detection means reaches the lower limit of the second set value, the second switch means is turned on to increase the current by energizing from the power source, and the second When the detection value of the current detection means reaches the upper limit of the second set value, the operation of turning off the second switch means is repeated,
When receiving a signal to end the maintenance of the second set value, the current is reduced without turning on the second switch means even when the current reaches the lower limit of the second set value.
When starting to drive the second electromagnetic load, turn on the first and fourth switch means,
When the detection value of the first or third current detection means reaches a first set value, the first and fourth switch means are turned off, and the feedback diode is energized to feed back the current. ,
When the detection value of the first current detection means reaches a predetermined threshold value or after a predetermined time has elapsed after turning off the first and fourth switch means, the fourth switch means is turned on. And circulating the current by energizing the diode,
When the detection value of the third current detection means reaches the lower limit of the second set value, the second switch means is turned on, the current is supplied from the power source to increase the current, and the third switch When the detection value of the current detection means reaches the upper limit of the second set value, the operation of turning off the second switch means is repeated,
When receiving the signal to end the maintenance of the second set value, the process of decreasing the current without turning on the second switch means even when the current reaches the lower limit of the second set value. ,
An electromagnetic load control device that repeats alternately.

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