JP2001349462A - Valve drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of switching means and harnesses in a drive to electromagnetically drive an internal combustion engine while maintaining a simple structure. SOLUTION: In this valve drive, valve opening and closing action is executed by changing between energization and non-energization of an excitating current to a first and a second electromagnets. The first and the second electromagnets are connected in series, a first switching means provided between one end of the first electromagnet and a grounding terminal, a second switching means provided between one end of the second electromagnet and the grounding terminal, and a third switching means provided between a connection terminal of the first solenoid to the second and a power supply are provided, the excitating current is energized to the first electromagnet, with the first switching means and the third switching means on, in opening a valve, and the excitating current is energized to the second electromagnet, with the second switching means and the third switching means on, in closing the valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve driving apparatus for driving a valve by an electromagnetic force, and more specifically, to a valve driving apparatus in which the number of components for controlling an energization state of an electromagnet for driving the valve is reduced. Related to the device.

[0002]

2. Description of the Related Art In general, in an actuator for driving a mechanical element, in addition to driving the mechanical element by mechanical driving by connecting a cam, a lot or the like, electromagnetic driving is performed. Also in vehicles, electromagnetic actuators are used in various places including opening and closing control of idle control valves, fuel injection valves, EGR control valves, and the like of engines. In particular, as a future possibility, it is desired to apply an electromagnetic actuator to an intake / exhaust valve of an internal combustion engine. When the intake / exhaust valve is driven by the electromagnetic actuator, the valve timing can be controlled in various ways as compared with the mechanical drive, and the output characteristics and fuel efficiency of the internal combustion engine can be improved.

Driving by an electromagnetic actuator excites an electromagnet by an electric signal, and drives a mechanical element by an attractive force of the generated electromagnet. Electromagnetic actuators are capable of finely controlling the drive timing and drive force by controlling electrical signals, and are therefore widely used in fields where precise timing control and variable control are desired.

Generally, an electromagnet that is excited to drive a valve in an electromagnetic actuator includes a pair of a valve-opening electromagnet and a valve-closing electromagnet. By supplying an exciting current to the valve-opening electromagnet, the valve is driven downward and open. By supplying an exciting current to the valve-closing electromagnet, the valve is driven upward and closed. Therefore, two driving devices, one for the valve-opening electromagnet and the other for the valve-closing electromagnet, are provided for each valve.

FIGS. 7A and 7B show general,
The drive devices for the valve-opening electromagnet and the valve-closing electromagnet are shown, respectively. As is apparent from FIG. 7, the two driving devices have the same configuration, and therefore only the driving device for the valve-opening-side electromagnet shown in FIG. 7A will be described.

[0006] A driving device 80 shown in FIG.
An electromagnet 81, an FET (field effect transistor) 82 for controlling the timing of energizing the electromagnet 81, an FET 83 for controlling an exciting current supplied to the electromagnet 81, an FET 83
When the flywheel diode 84 and the FETs 82 and 83 for turning off the back electromotive force generated in the electromagnet 81 as the flywheel current when the switch is turned off, the magnetic energy stored in the electromagnet 81 is regenerated. A regeneration diode 85 is provided. The terminal 86 is supplied with a power supply voltage.

[0007] Usually, the exciting current is controlled by a current control signal based on constant current feedback. Thus,
The FET 83 is turned on / off by a current control signal,
A predetermined exciting current is caused to flow through the electromagnet 81. Note that other switching means (for example, a bipolar transistor) are used instead of the FET. In some cases, the excitation current is controlled by a pulse-width modulated (PWM) signal instead of the current control signal.

The operation of the circuit shown in FIG. 7A will be briefly described. When the valve opening operation is performed, the FET 82 is turned on, and the FET 83 is turned on / off. In this way, the exciting current flows through the FET 82 through the electromagnet 81 while being controlled by the FET 83. When stopping the valve opening operation, both the FET 82 and the FET 83 are turned off. Since magnetic energy is stored in the electromagnet 81, it is regenerated to the power supply via the regenerative diode 85.

Thus, the conventional drive device is provided with two switching means and two diodes per electromagnet, thus requiring four switching means and four diodes per valve. (FIGS. 7A and 7B). Switching means such as transistors could be used instead of the diodes shown in FIG. 7, but this would require eight switching means per valve.
Further, in the driving device shown in FIG.
Two per magnet is required, so 4 per valve
Japanese Unexamined Patent Application Publication No. 11-62528 discloses that, in addition to the above-described driving device, two transistors for supplying an exciting current to the electromagnet and an electromagnet for eliminating residual magnetism remaining in the electromagnet are disclosed. Discloses a driving device including two transistors for passing currents in opposite directions. Japanese Patent Application Laid-Open No. H11-210916 has two switching elements for supplying an exciting current to an electromagnet in a forward direction and two switching elements for supplying an exciting current in a reverse direction to an electromagnet. Describes a driving device that turns on either the forward switching element or the reverse switching element in accordance with the deviation of. Each of these drives requires eight switching means per valve.

As described above, if a total of eight switching means are provided for each valve, for example, in the case of an internal combustion engine having four cylinders each having four valves per cylinder, the total number of valve driving devices becomes sixteen. The total number of required switching means is 128. Further, the required number of harnesses is 64. As a result, the number of components constituting the drive device is increased, which leads to an increase in cost.

Japanese Patent Application Laid-Open No. 11-166657 discloses that
9 FETs per electromagnet (or 8 FETs)
And a single diode), and the on / off state of each switching means is switched as needed to reduce the number of switching means.

[0012]

The above-mentioned JP-A-11-1
Although the driving device disclosed in Japanese Patent Publication No. 66657 reduces the number of switching means, it is necessary to newly provide a means for switching on / off states of these switching means in order to realize excitation of the electromagnet, flywheel and regenerative means. There is. Further, even if the number of switching means is reduced, the cost of the FET is relatively higher than that of the diode.

It is desirable to realize a valve drive device which can minimize costs by minimizing the number of components constituting the drive device and can be assembled with a simple structure.

Therefore, the present invention utilizes the configuration of the conventional driving device shown in FIG. 7 and shares a part of the switching means and the diode for the valve opening operation and the valve closing operation. It is an object of the present invention to provide a valve driving device capable of reducing the number of components while maintaining a simple configuration.

[0015]

According to a first aspect of the present invention, there is provided a valve driving apparatus for opening and closing a valve by switching between energization and non-energization of an exciting current to first and second electromagnets. A valve driving device for performing an operation, wherein the first and second electromagnets are connected in series, and a first switching device provided between one end of the first electromagnet and a ground terminal. Means, a second switching means provided between one end of the second electromagnet and a ground terminal, and a second switching means provided between a connection terminal of the first and second electromagnets and a power supply. Switching means, when the valve is to be opened, the first switching means and the third switching means are turned on to supply an exciting current to the first electromagnet, Should be closed When, by the second switching means and the third switching means in the ON state, passing a 励時 current to the second electromagnet, a configuration called.

According to the first aspect of the present invention, since the third switching means is used commonly for the valve opening operation and the valve closing operation, the switching means and the number of harnesses are maintained while maintaining a relatively simple circuit configuration. Can be reduced.

According to a second aspect of the present invention, in the valve driving apparatus of the first aspect, a first diode provided between one end of the first electromagnet and the power supply and one of the second electromagnets are provided. And a third diode provided between the first and second electromagnets and a ground terminal, the first switching means and the third diode being provided between the first and second electromagnets and the ground terminal. When the switching means is turned off to stop the valve opening operation, the voltage induced in the first electromagnet is discharged through the first and third diodes, and the second switching means and the second switching means are turned off. When the switching means of No. 3 is turned off and the valve closing operation of the valve is stopped, the voltage induced in the second electromagnet is discharged through the second and third diodes.

According to the second aspect of the present invention, since the third diode is used commonly for the valve opening operation and the valve closing operation, the number of diodes is reduced while maintaining a relatively simple circuit configuration. be able to.

According to a third aspect of the present invention, there is provided a valve driving apparatus for performing a valve opening / closing operation by switching between energizing and non-energizing of an exciting current to a first and a second electromagnet. The two electromagnets are connected in series, and a first switching means provided between one end of the first electromagnet and a power supply, and a first switching means provided between one end of the second electromagnet and the power supply. And a third switching means provided between a connection terminal of the first and second electromagnets and a ground terminal, and when the valve is to be opened, When the first switching means and the third switching means are turned on to supply an exciting current to the first electromagnet and the valve is to be closed, the second switching means and the third switching means are turned on. Switchon And means in the on state, passing a 励時 current to the second electromagnet, a configuration called.

According to the third aspect of the present invention, since the third switching means is used commonly for the valve opening operation and the valve closing operation, the switching means and the number of harnesses are maintained while maintaining a relatively simple circuit configuration. Can be reduced.

According to a fourth aspect of the present invention, in the valve driving device according to the third aspect of the present invention, a first diode provided between one end of the first electromagnet and a ground terminal, and a second diode connected to the second electromagnet. A second diode provided between one end and the ground terminal, a third diode provided between a connection terminal of the first and second electromagnets and the power supply, and a first switching Means and the third switching means are turned off to stop the valve opening operation, and the voltage induced in the first electromagnet is discharged through the first and third diodes, and the second electromagnet is discharged. When the switching means and the third switching means are turned off to stop the valve closing operation, the voltage induced in the second electromagnet is discharged via the second and third diodes.
Take the configuration.

According to the fourth aspect of the present invention, since the third diode is used commonly for the valve opening operation and the valve closing operation, the number of diodes is reduced while maintaining a relatively simple circuit configuration. be able to.

[0023]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the electromagnetic actuator control device. The control device 1 includes a central processing unit 2 (hereinafter, referred to as a “CPU”) including a microcomputer and circuit elements associated therewith.
A ROM 3 (read-only memory) for storing a program and data to be executed, a RAM 4 (random access memory) for providing a work area at the time of execution and storing calculation results and the like, and an input / output interface 5.

The input / output interface 5 includes an engine speed (Ne), an engine coolant temperature (Tw), and an intake air temperature (T
a), a signal from various sensors 8 representing a battery voltage (VB) and an ignition switch (IGSW) is inputted, and a desired torque detected by the required load detecting means 9 is inputted. The required load detection means 9 can be realized by, for example, an accelerator pedal sensor that detects the amount of depression of the accelerator pedal. Based on these inputs, the control device 1 determines parameters such as the timing of power supply, the magnitude of the current or voltage to be supplied, and the time for supplying the current or voltage in accordance with a control program stored in the ROM 3 in advance. , Electromagnetic actuator 10
A control signal for appropriately controlling 0 is output to the current control circuit 7 via the input / output interface 5.

The current control circuit 7 generates a current control signal based on a control signal from the control device 1, and supplies the current control signal to the drive circuit 8. The drive circuit 8 controls a current supplied from the constant voltage source 6 according to the received current control signal, and a predetermined exciting current flows through the first electromagnet 11 and the second electromagnet 13 provided in the electromagnetic actuator 100. To do.

A current detector 10 is connected to the drive circuit 8, and the current detector 10 detects the magnitude of the current supplied to the first and second electromagnets 11 and 13 and detects the magnitude of the current supplied to the first and second electromagnets 11 and 13. Feedback to The control device 1 supplies a parameter for changing the current control signal to the current control circuit 7 based on the feedback signal. As a result, the changed current control signal is supplied to the current control circuit 7.
Is output to the drive circuit 8. As described above, the current control circuit 7 can supply the optimized excitation current to the first and second electromagnets 11 and 13 in order to improve the fuel efficiency, reduce the emission, and improve the horsepower of the internal combustion engine.

FIG. 2 shows the electromagnetic actuator 100 of FIG.
It is sectional drawing which shows the outline structure of. The valve 20 is provided at an intake port or an exhaust port (hereinafter, referred to as an intake / exhaust port 30) of the internal combustion engine, and opens and closes the intake / exhaust port 30. When the valve 20 is driven upward by the electromagnetic actuator 100, the valve 20 comes into close contact with a valve seat 31 provided in the intake / exhaust port 30 of the engine and stops and closes the intake / exhaust port 30. When the valve 20 is driven downward by the electromagnetic actuator 100, the valve 20 leaves the valve seat 31, descends to a position away from the valve seat 31 by a predetermined distance, and opens the intake / exhaust port 30.

A valve shaft 21 is connected to the valve 20 upward. Valve shaft 21
Is held movably in the axial direction by a valve guide 23, and an armature 22 on a disk made of a soft magnetic material is attached to an upper end thereof. The armature 22 is urged from above and below by a first spring 16 and a second spring 17.

A first solenoid type electromagnet 11 located above the armature 22 and a second solenoid type electromagnet 13 located below the armature 22 are provided in a housing 18 made of a non-magnetic material of the electromagnetic actuator 100. Is provided. The first electromagnet 11 is surrounded by a first magnetic yoke 12, and the second electromagnet 13 is surrounded by a second magnetic yoke 14. The first spring 16 and the second spring 17 allow the armature 22 to move between the first electromagnet 11 and the second electromagnet 11 in a state where no exciting current is applied to either the first electromagnet 11 or the second electromagnet 13. The balance is provided such that it is located in the middle between the electromagnets 13.

When an exciting current is applied to the first electromagnet 11 by the drive circuit 8, the first magnetic yoke 12 and the armature 22 are magnetized and attract each other, and the armature 22 is attracted upward. As a result, the valve 20 is driven upward by the valve shaft 21, comes into close contact with the valve seat 31, stops, and enters a closed state.

When the supply of the exciting current to the first electromagnet 11 is stopped and the exciting current is supplied to the second electromagnet 13, the second
The magnetic yoke 14 and the armature 22 are magnetized and a force acts to attract the armature 22 downward, and the armature 22 is driven downward in combination with the action of gravity,
It stops in contact with the second magnetic yoke 14. As a result, the valve 20 is driven downward by the valve shaft 21, and the valve 20 is opened.

As described above, the driving device for a conventional electromagnetic valve shown in FIG. 7 includes a valve-opening electromagnet 81 (corresponding to the second electromagnet 13 in FIG. 2) and a valve-closing electromagnet 91.
(Corresponding to the first electromagnet 11 in FIG. 2). However, as described above, the electromagnets on the valve opening side and the valve closing side are not simultaneously energized. That is, the driving device 90 shown in FIG. 7B is not used during the valve opening operation, and the driving device 80 shown in FIG. 7A is not used during the valve closing operation. Therefore, by using a part of the switching means and the diode constituting the driving device in common during the valve opening operation and the valve closing operation, the driving device in which the number of the switching means, the diode and the harness is reduced is provided. Can be realized.

FIG. 3 shows a driving device 50 according to the present invention. One drive device 50 is provided for one valve. The driving device 50 includes first and second electromagnets 11 and 13 and first and second timing FETs 51A.
51B, a current control FET 53, a flywheel diode 55, and first and second regenerative diodes 57A and 57B. The first and second electromagnets 11 and 13 correspond to the first and second electromagnets 11 and 13 shown in FIGS. 1 and 2, respectively. The components of the driving device 50 other than the first and second electromagnets correspond to the driving circuit 8 in FIG.

The first timing FET 51A is a switching means realized by an N-channel FET. The source terminal is connected to the ground terminal 62, the drain terminal is connected to the first electromagnet 11, and the gate terminal is current controlled. Connected to circuit 7. Second timing FET 51
B has the same configuration as the first timing FET 51A, except that the source terminal is connected to the second electromagnet 13. Here, the first and second timing F
Although an N-channel FET is used for the ETs 51A and 51B, a P-channel FET may be used instead.

The current control FET 53 is a P-channel FE
T is a switching means realized by T, the drain terminal is connected to both the first and second electromagnets 11 and 13, the source terminal is connected to the power supply terminal 61, and the gate terminal is connected to the current control circuit 7. . Power supply terminal 61
Is connected to the constant voltage source 6 of FIG. Here, a P-channel FET is used as the current control FET 53, but an N-channel FET may be used instead.

The first and second timing FETs and current control FETs may be replaced by power transistors or IGBTs (insulated gate bipolar transistors).
For example, it can be realized by an arbitrary switching element.

The flywheel diode 55 has an anode terminal connected to the ground terminal 62 and a cathode terminal connected to both the first and second electromagnets 11 and 13. The first regenerative diode 57A has an anode terminal connected to the FET 51A side terminal of the first electromagnet 11,
The cathode terminal is connected to the power supply terminal 61. The second regeneration diode 57B has an anode terminal connected to the second electromagnet 1
3 except that it is connected to the terminal on the FET 51B side.
It has the same configuration as the first regenerative diode 57A.

The drive device 50 uses the current control FET 53 and the flywheel diode 55 in common when opening and closing the valve. Hereinafter, the operation of the driving device 50 in the opening and closing operation of the valve will be described.

FIG. 4 shows the FETs 51A, 51A,
It is a figure which shows the timing of ON / OFF operation of 1B and 53. FIG. 4A illustrates a case where the valve opening operation is performed over a period of time t1 to t3, and FIG.
Shows a case where the valve closing operation of the valve is performed over the time t4 to t6.

First, the valve opening operation of the valve will be described. The control device 1 outputs a control signal required for the valve opening operation to the current control circuit 7, and the current control circuit 7 generates a current control signal for flowing a predetermined exciting current in response thereto.

At time t1 in FIG. 4A, the timing FET 51A is turned on in response to the control signal from the controller 1, and the current control FET 53 is also turned on by the current control circuit 7 supplied from the current control circuit 7. It turns on in response to a signal. During the valve opening operation, the FET 51A
Is maintained in an on state, and the FET 53 is driven on / off in accordance with the current control signal. Second timing FET
51B remains off.

When both the FET 51A and the FET 53 are in the ON state as in the time t1 to t2, the exciting current flows through the first electromagnet 11 and the FET 51A and the ground terminal as shown by a broken line 71 (FIG. 3). Flow to 62. Thus, the first electromagnet 11 is excited, and the valve opening operation is performed as described above.

As shown at time t2, the FET 51A
When the FET 53 changes from the on-state to the off-state while the switch remains in the on-state, a back electromotive force is induced in the first electromagnet 11, and a high voltage is generated on the negative electrode side (the FET 51A side) of the first electromagnet 11. At this time, the electromagnet 11 tries to keep flowing the current in the same direction as when the voltage was supplied.

On the other hand, since the FET 53 is turned off, a closed circuit from the negative electrode side of the first electromagnet 11 to the positive electrode side (FET 53 side) of the first electromagnet 11 through the FET 51A and the flywheel diode 55. Is formed. Accordingly, the high voltage on the negative electrode side of the electromagnet 11 is discharged as a flywheel current flowing through this closed circuit, as shown by the broken line 72.

As described above, it is desirable that the flywheel diode 55 is a diode that realizes high-speed switching that can be adapted to the frequency of the current control signal supplied from the current control circuit 7.

Next, at time t3 in FIG.
Stop the valve opening operation. FE for first timing
At the same time as T51A is turned off in response to the control signal from the control device 1, the current control FET 53 is also turned off because the supply of the current control signal is stopped. As described above, the back electromotive force is induced in the first electromagnet 11 to generate a high voltage on the negative electrode side, and the electromagnet 11 tries to continue the current in the same direction as when the voltage was supplied. I do. Since the FETs 51A and 53 are off, the flywheel diode 5
5. First electromagnet 11 and first regenerative diode 5
A current path through 7A is formed. Therefore, the high voltage generated on the negative electrode side is discharged to the power supply side through the regeneration diode 57A and the power supply terminal 61. Thus, the magnetic energy stored in the first electromagnet 11 is regenerated to the power supply side.

Next, the valve closing operation of the valve will be described. The valve closing operation of the valve is basically the same as the valve opening operation of the valve, and will be described only briefly. The control device 1 outputs a control signal necessary for executing the valve closing operation to the current control circuit 7, and the current control circuit 7 generates a current control signal in response thereto.

At time t4 in FIG. 4B, the timing FET 51B is turned on in response to the control signal, and at the same time, the current control FET 53 is turned on in response to the current control signal. During the valve closing operation, the FET
51B is maintained in the on state, and the FET 53 is driven on / off. The first timing FET 51A remains off.

When both the FET 51B and the FET 53 are in the ON state, the exciting current flows through the second electromagnet 13 to the FET 51B and the ground terminal 62, as indicated by a broken line 75. Thus, the second electromagnet 13 is excited, and the valve closing operation is performed.

As shown at time t5 in FIG. 4B, when the FET 53B is turned on and the FET 53 is turned off from the on state, a back electromotive force is induced in the second electromagnet 13 and the electromagnet 13 Negative side (FE for timing)
A high voltage is generated at T51B side). On the other hand, a closed circuit is formed from the negative electrode side of the electromagnet 13 to the positive electrode side (FET53 side) of the second electromagnet 13 through the timing FET 51B and the flywheel diode 55. Therefore, the high voltage is discharged as a flywheel current flowing through the closed circuit as shown by a broken line 76.

Next, at time t6 in FIG. 4B, the valve closing operation is stopped. Timing FET51B
Is turned off in response to the control signal, and at the same time, the current control FET 53 is also turned off because the supply of the current control signal is stopped. As described above, the back electromotive force is induced in the second electromagnet 13 to generate a high voltage on the negative electrode side. On the other hand, as shown by the broken line 77, a current path is formed that passes through the flywheel diode 55, the second electromagnet 13, and the second regenerative diode 57B. Therefore, the high voltage is regenerated to the power supply through the regenerative diode 57B.

Thus, in the opening and closing operation of the valve,
By using the current control FET 53 and the flywheel diode 55 in common, the number of elements constituting the drive circuit can be reduced. Specifically, a switching valve and three diodes are provided for each valve. Therefore, in the case of an internal combustion engine having four valves per cylinder and four cylinders, a conventional electromagnetic valve driving device (FIG. 7)
In the valve driving device according to the present invention, the number of switching means and the number of diodes are reduced to 48, while the number of switching means and the number of diodes are 64. That is, the number of switching means and the number of diodes are each reduced by 25%. Considering only the flywheel diode, the number is reduced from 32 to 16 in the conventional case, which corresponds to a 50% reduction.
The number of harnesses is 64 in the conventional driving device (FIG. 7).
In contrast to the necessity for this, in the drive device according to the present invention, 4
It is reduced to eight, which corresponds to a 25% reduction.

As described above, according to the valve driving device of the present invention, the number of switching means, diodes and harnesses can be significantly reduced. Further, the valve driving device according to the present invention is relatively easy to assemble because the configuration of the conventional driving device is used and it is not necessary to newly provide complicated switching switching means.

FIG. 5 shows another embodiment of the driving device according to the present invention. The driving device 60 includes a timing FET 51.
And that the regenerative diode 57 is used in common.
Different from the driving device 50.

The driving device 60 includes first and second electromagnets 11 and 13, a timing FET 51, first and second current control FETs 53A and 53B, and first and second flywheel diodes 55A and 55.
B, a regeneration diode 57 is provided. First electromagnet 11
The second electromagnet 13 corresponds to the first and second electromagnets 11 and 13 shown in FIGS. 1 and 2, respectively. The components of the driving device 60 other than the first and second electromagnets correspond to the driving circuit 8 in FIG.

The timing FET 51 has an N-channel F
ET is a switching means realized by the ET. The source terminal is connected to the ground terminal 62 and the drain terminal is connected to the first terminal.
And connected to both the second electromagnets 11 and 13,
The gate terminal is connected to the current control circuit 7. here,
Although an N-channel FET is used as the timing FET 51, a P-channel FET may be used instead.

The first current control FET 53A is a switching means realized by a P-channel FET, and has a drain terminal connected to the first electromagnet 11, a source terminal connected to the power supply terminal 61, and a gate terminal connected to the current terminal. Connected to control circuit 7. The power supply terminal 61 is connected to the constant voltage source 6 in FIG. The second current control FET 53B is
Except that the drain terminal is connected to the second electromagnet 13, it has the same configuration as the first current control FET 53A. Here, the first and second current control FETs 53
Although P-channel FETs are used for A and 53B, N-channel FETs may be used instead.

First Flywheel Diode 55A
Has an anode terminal connected to the ground terminal 62 and a cathode terminal connected to the first electromagnet 11. The second flywheel diode 55B has the same configuration as the first flywheel diode 55A, except that the cathode terminal is connected to the second electromagnet 13. The regenerative diode 57 has an anode terminal connected to the FET 51 side terminal of each of the first and second electromagnets 11 and 13, and a cathode terminal connected to the power supply terminal 61.

FIG. 6 shows the F of the driving device 60 shown in FIG.
It is a figure which shows the timing of ON / OFF operation | movement of ET51, 53A and 53B. FIG. 6A shows time t1 to t.
3 illustrates a case where the valve opening operation is performed over a period of time 3, and FIG. 6B illustrates a case where the valve closing operation is performed over a period of time t4 to t6.

The valve opening operation of the valve will be described. The control device 1 outputs a control signal necessary for the valve opening operation to the current control circuit 7, and the current control circuit 7 generates a current control signal in response thereto.

At time t1 in FIG. 6A, the timing FET 51 is turned on in response to the control signal from the control device 1, and at the same time, the current control FET 53A is turned on.
Is also turned on in response to the current control signal supplied from the current control circuit 7. During the valve opening operation, the FET 51
Is maintained in the ON state, and the FET 53A is driven on / off. The second current control FET 53B remains off.

As shown in time t1 to t2 in FIG.
When both the FET 51 and the FET 53A are in the ON state, the exciting current flows through the first electromagnet 11 to the FET 51 and the ground terminal 62 as shown by a broken line 81. Thus, the first electromagnet 11 is excited, and the valve opening operation is performed.

As shown at time t2 in FIG. 6A, when the FET 53A changes from the on state to the off state while the FET 51 remains on, a back electromotive force is induced in the first electromagnet 11, and the electromagnet 11 A high voltage is generated on the negative electrode side (FET 51 side). At this time, the electromagnet 11 tries to keep flowing the current in the same direction as when the voltage was supplied.

On the other hand, since the FET 53A is in the off state, the timing FET 51
Then, a closed circuit is formed that passes through the first flywheel diode 55A and reaches the positive electrode side (FET53A side) of the electromagnet 11. Accordingly, the high voltage on the negative electrode side of the electromagnet 11 is discharged as a flywheel current flowing through this closed circuit, as shown by the broken line 82.

Next, at time t3 in FIG.
Stop the valve opening operation. FET 51 is the control device 1
At the same time, the current control FET 53A is turned off because the supply of the current control signal is stopped. As described above, the back electromotive force is induced in the electromagnet 11 to generate a high voltage on the negative electrode side, and the electromagnet 1
1 will continue to flow current in the same direction as when the voltage was being supplied. Since both the FETs 51 and 53A are in the OFF state, a current path is formed through the flywheel diode 55A, the first electromagnet 11, and the regenerative diode 57, as shown by the broken line 83. Therefore, the high voltage is discharged to the power supply terminal 61 through the regenerative diode 57. Thus, the first electromagnet 11
The magnetic energy stored in the battery is regenerated to the power supply.

The closing operation of the valve will be described. The valve closing operation of the valve is basically the same as the valve opening operation of the valve. The control device 1 outputs a control signal necessary for the valve closing operation to the current control circuit 7, and the current control circuit 7 generates a current control signal in response thereto.

At time t4 in FIG. 6B, the timing FET 51 is turned on in response to the control signal, and at the same time, the current control FET 53B is turned on in response to the current control signal. During the valve closing operation, the FET
51 is maintained in the on state, and the FET 53B is driven on / off. The first current control FET 53A remains off.

When both the FET 51 and the FET 53 are in the ON state, the exciting current flows through the second electromagnet 13 and the FET 51 and the ground terminal 6 as shown by a broken line 85.
2 is energized. Thus, the second electromagnet 13 is excited, and the valve closing operation is performed.

As shown at time t5 in FIG. 6 (b), the FET 51 remains on while the timing FET 51 remains on.
When 53B changes from the on state to the off state, back electromotive force is induced in the second electromagnet 13 and the negative side (FE
A high voltage is generated at T51B side). On the other hand, the second electromagnet 1
A closed circuit is formed from the negative electrode side of No. 3 to the positive electrode side (FET 53 side) of the electromagnet 13 through the timing FET 51 and the flywheel diode 55B. Accordingly, the high voltage is discharged as a flywheel current flowing through the closed circuit as shown by a broken line 86.

Next, at time t6 in FIG.
Stop the valve closing operation. Timing FET 51
Is turned off in response to the control signal, and at the same time, the current control FET 53B is also turned off because the supply of the current control signal is stopped. As described above, the second electromagnet 13
, A high voltage is generated on the negative electrode side, and the electromagnet 13 tries to discharge this high voltage. On the other hand, as shown by a broken line 87, the flywheel diode 55
B, a current path passing through the second electromagnet 13 and the regenerative diode 57 is formed. Therefore, the high voltage is
It is regenerated to the power supply side through the regenerative diode 57.

Thus, in the opening and closing operation of the valve,
By using the timing FET 51 and the regenerative diode 57 in common, the driving device 60
The number of switching means, diodes and harnesses can be reduced by the same number as in the case of the driving device 50 shown in FIG. In the drive device 50, the flywheel diode is reduced by 50%. In the drive device 60, the regeneration diode is reduced by 50%. Further, since the configuration of the conventional driving device is used similarly to the case of the driving circuit 50, the driving device 60 is relatively easy to assemble.

[0072]

According to the first aspect of the present invention, since the third switching means is used commonly for the valve opening operation and the valve closing operation, a relatively simple circuit configuration is provided. And the number of switching means and the number of harnesses can be reduced.

According to the second aspect of the present invention, since the third diode is used commonly for the valve opening operation and the valve closing operation, the number of diodes can be reduced while maintaining a relatively simple circuit configuration. be able to.

According to the third aspect of the present invention, since the third switching means is used commonly for the valve opening operation and the valve closing operation, the switching means and the number of harnesses can be maintained while maintaining a relatively simple circuit configuration. Can be reduced.

According to the fourth aspect of the present invention, since the third diode is used commonly for the valve opening operation and the valve closing operation, the number of diodes can be reduced while maintaining a relatively simple circuit configuration. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an entire electromagnetic actuator and its control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic sectional view of an electromagnetic actuator according to one embodiment of the present invention.

FIG. 3 is a diagram showing a valve driving device according to an embodiment of the present invention.

FIG. 4 is a diagram showing operation timings of switching means of the valve driving device according to one embodiment of the present invention.

FIG. 5 is a view showing a valve driving device according to another embodiment of the present invention.

FIG. 6 is a diagram showing operation timings of switching means of the valve driving device according to another embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a conventional valve driving device.

[Description of Signs] 1 Control device 6 Constant voltage source 7 Current control circuit 8 Drive circuit 11 First electromagnet 13 Second electromagnet 20 Valve 51, 53 Switching means 55, 57 Diode

Claims (4)

[Claims] 1. A valve driving device for opening and closing a valve by switching between energizing and non-energizing of an exciting current to first and second electromagnets, wherein the first and second electromagnets are connected in series. A first switching means provided between one end of the first electromagnet and a ground terminal; and a first switching means provided between one end of the second electromagnet and a ground terminal. Second switching means, and third switching means provided between a connection terminal of the first and second electromagnets and a power supply, wherein when the valve is to be opened, the first Turning on the switching means and the third switching means,
When an exciting current is supplied to the first electromagnet and the valve is to be closed, the second switching means and the third switching means are turned on,
A valve driving device configured to supply an exciting current to the second electromagnet. 2. A first diode provided between one end of the first electromagnet and a power supply, and a second diode provided between one end of the second electromagnet and a power supply. A third diode provided between the first and second electromagnets and a ground terminal; and turning off the first switching means and the third switching means to open the valve. When the valve operation is stopped, the voltage induced in the first electromagnet is discharged through the first and third diodes, and the second switching means and the third switching means are turned off, and 2. The valve driving device according to claim 1, wherein when the valve closing operation of the valve is stopped, a voltage induced in the second electromagnet is discharged through the second and third diodes. 3. 3. A valve driving device for opening and closing a valve by switching between energizing and non-energizing of an exciting current to a first and a second electromagnet, wherein the first and second electromagnets are connected in series. A first switching means provided between one end of the first electromagnet and a power supply; and a second switching means provided between one end of the second electromagnet and a power supply. 2 switching means, and third switching means provided between a connection terminal of the first and second electromagnets and a ground terminal, wherein the first switching is performed when the valve is to be opened. Means and the third switching means in the on state,
When an exciting current is supplied to the first electromagnet and the valve is to be closed, the second switching means and the third switching means are turned on,
A valve driving device configured to supply an exciting current to the second electromagnet. 4. A first diode provided between one end of the first electromagnet and a ground terminal, and a first diode provided between one end of the second electromagnet and a ground terminal. A second diode, and a third diode provided between a connection terminal of the first and second electromagnets and a power supply, wherein the first switching unit and the third switching unit are turned off. When the valve opening operation of the valve is stopped, the voltage induced in the first electromagnet is discharged through the first and third diodes, and the second switching means and the third switching means are turned off. 4. The valve driving device according to claim 3, wherein when the valve closing operation of the valve is stopped in a state, a voltage induced in the second electromagnet is discharged through the second and third diodes. .