JPH10213258A - Solenoid valve drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing costs of a solenoid valve device by employing therein a pair of solenoid valves, one of which is used also as a choke coil in existing drives. SOLUTION: A solenoid valve drive comprises a first solenoid valve 3 driven with a current supplied from a power supply source 1 and its associated first selector means 4, a second solenoid valve 5 connected in parallel with the first solenoid valve 3 and its associated second selector means 6, a CPU 7 which controls the duty of the first selector means 4 to lead a supply current to the first solenoid valve 3 and breaks the second selector means 6 during the control duration, and a bypass line which is connected at its one end between the first selector means 4 and the first solenoid valve 3 and at the other between the second selector means 6 and the second solenoid valve 5, and is provided with an element having a characteristic to lead a current between both connected ends substantially in the direction from the side of the first selector means 4 to the side of the second selector means 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve driving device, and more particularly to a driving device having a plurality of solenoid valves that receive parallel power supply from a power supply.

[0002]

2. Description of the Related Art Conventionally, a solenoid circuit of a solenoid valve which is used in an anti-skid control device and is duty-controlled (PWM controlled) is driven by a drive circuit as shown in FIG. In the apparatus shown in FIG. 9, the first solenoid valve 3 is duty-driven. That is, the switching of the first drive IC 4 executes the duty control for controlling the average current flowing to the first solenoid valve 3.

The drive circuit shown in FIG. 9 includes first and second drive ICs 4 and 6 which are driven by receiving a drive signal from a central processing unit 7 (hereinafter referred to as a CPU 7). The signal from the CPU 7 transmits an electronic signal to the first and second driving ICs 4 and 6 via a buffer or the like (not shown). When each drive IC is turned on, the power supply source 1
Are supplied to the first and second solenoid valves 3, 5 corresponding to the respective drives 1C4, 6. For example, when the first drive IC 4 is ON, a current flows from the power supply source 1 to the first solenoid valve 3 and the first drive IC 4 through the diode 2 and the choke coil 9. Immediately after the first drive IC 4 is turned off, the first drive IC 4 is turned off.
The current is circulated in the solenoid valve 3 and the reflux diode 8 connected in parallel with the first solenoid valve 3. In addition, a return diode may be connected in parallel to the second solenoid valve 5 as well, but illustration and description are omitted because they exhibit the same operation as the return diode 8. When the second solenoid valve 6 is not duty driven,
The freewheel diode in the second solenoid valve 5 is not required.

Here, when the first solenoid valve 3 is duty-driven, the first drive IC 4
When switching from FF (interruption) to ON (energization), there is a problem that the freewheeling diode 8 connected in parallel with the first solenoid valve 3 does not enter the reverse blocking state at the same time when the first drive IC 4 is turned on. . That is, the first drive I
First drive IC with a momentary delay from C4 ON
A reverse blocking state (one-way conduction state) from the power supply source 1 side to the power supply source 1 side is established. During this delay, a return current (hereinafter referred to as a through current) flows from the power supply source 1 through the return diode 8 and the first drive IC 4. Since the change in the through current is very rapid, a surge voltage is generated by parasitic inductance due to wiring in the circuit. Therefore, the freewheeling diode 8 and the first driving IC
There is a problem that the withstand voltage design margin of the device No. 4 must be large. Also, the surge voltage and the surge current cause radio noise and the like.

For this reason, conventionally, as shown in FIG.
A choke coil 9 is provided upstream of the first solenoid valve 3 to serve as a through current suppressing coil for preventing a sudden change in the through current.

[0006]

However, there is a problem that the provision of the choke coil increases the number of parts and increases the cost. In particular, when the number of solenoids driven by the solenoid valve driving device is large, for example, when the solenoid valve driving device is employed in an anti-skid control device or the like, the number of the choke coils 9 increases, resulting in a large cost burden.
If the choke coil 9 is not used, it is necessary to use a freewheeling diode having a small response delay and a high response performance as described above, which also causes a problem that the cost is increased.

Accordingly, an object of the present invention is to provide a solenoid valve driving device capable of reducing costs by making the other solenoid valve of a pair of solenoid valves function instead of a conventional choke coil. .

[0008]

In order to solve the above-mentioned problems, in a solenoid valve driving device according to the present invention, one end is connected between the first switching means and the first solenoid valve, and the other end is connected to the first solenoid valve. An element connected between the second switching means and the second solenoid valve and having a characteristic that the direction of current flow between both ends of the connection does not substantially impede the return current in the first solenoid valve. The main feature of the present invention is to provide a bypass path having:

By employing such a configuration, the through current generated at the time of switching from OFF to ON when the first switching means is duty-driven with respect to the first solenoid valve is reduced to the second current. It can be suppressed by a solenoid valve. In this manner, by providing the solenoid valve that is not driven in the pair of first and second solenoid valves with the effect of suppressing the through current, the number of components in the solenoid valve driving device can be reduced. The pair of first and second solenoid valves includes at least one duty-driven first solenoid valve, and the first solenoid valve includes a first solenoid valve.
This means that there is a combination in which at least one second solenoid valve that is not energized while the solenoid valve is being duty-driven is present.

If a bypass path is formed in the electronic control unit as described in claim 2, a noise reduction effect can be obtained. Further, if the present invention is applied to a brake system such as an anti-skid control device as described in claim 3, the number of sets of the first and second solenoid valves employed in the anti-skid control device is large. This has the effect of reducing the number of parts. Further, in the anti-skid control device, the first
When the solenoid valve is duty driven, the second solenoid valve used as a pressure reduction control valve is generally driven in a non-energized state, so that the present invention is easily applied.

Further, a diode may be used as an element in the bypass path. In addition, as described in claim 6, one of the first switching means and the second switching means is duty-controlled, and the other switching means is in a cutoff state. The other end is connected between the switching means and the first solenoid valve, the other end is connected between the second switching means and the second solenoid valve, and the control means controls the first or second switching means. A solenoid valve drive device including a bypass path including a determination unit that determines a direction in which a current flows between both ends of the connection depending on which is subjected to duty control may be employed.

In such a configuration, in addition to the fact that the through current can be suppressed by a solenoid valve that is not duty-driven, duty driving of both the first and second solenoid valves is possible. . That is, for example, when a diode is used as described in claim 4, only one solenoid valve can be duty-driven, but in the invention described in claim 6, both solenoid valves can be duty-driven.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solenoid valve driving device to which the present invention is applied will be described below with reference to the drawings. A first embodiment will be described based on FIG. It is to be noted that components having the same operation as the configuration described in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 1, the structural features of the first embodiment are the same as those of the first embodiment.
Between the solenoid valve 3 and the first drive IC 4 and the second
The reflux diode 10 is configured in a path that bypasses between the solenoid valve 5 and the second drive IC 6. The reflux diode 10 is connected so as to substantially permit only conduction from the first solenoid valve 3 side to the second solenoid valve 5 side.

The CPU 7 controls the first drive IC 4 by transmitting an electric signal to the first drive IC 4 so as to perform duty driving of the first solenoid valve 3.
During the duty driving of the second driving IC 6, the second driving IC 6 is controlled to be in the cutoff state. The operation and effect of the reflux diode 10 thus connected will be described below. In the duty driving of the first solenoid valve 3 under the control of the first drive IC 4, first, when the first drive IC 4 is in the ON state, power is supplied from the power supply source 1 to the first solenoid valve 3. Next, when the first drive IC 4 is switched from ON to OFF, a return passage is formed in the return diode 10 and the first and second solenoid valves 3 and 5 during the OFF period. Next, when the first drive IC 4 is switched from OFF to ON, the above-described through current flows from the power supply source 1 through the second solenoid valve 5 due to the response delay of the return diode 10. And the first drive IC 4. However, the rise of the through current is suppressed by the inductance of the second solenoid valve 5.
That is, the freewheeling diode 10 is connected and arranged so that the second solenoid valve 5 that is not duty-driven out of the pair of first and second solenoid valves has the function of a conventional choke coil. The choke coil that has been used can be eliminated.

In this embodiment, as compared with the prior art described with reference to FIG. 9, the diode 2 for regulating the direction of current from the power supply can be eliminated. That is,
For example, a well-known MOS-FET is used for the first drive IC 4.
(Metai Oxide Semiconductor-Field Effect Transis
When tor) is employed, a parasitic diode (a diode connected in parallel to the first drive IC 4 that permits only one-way conduction from the ground side to the first solenoid valve 3 side) exists in this MOS-FET. Therefore, in FIG. 9, the power supply is reversely connected due to malfunction or erroneous operation (current is assumed to flow in the order of the first drive IC 4 → the first solenoid valve 3 and the return diode 8 → the choke coil 9 from the ground side). Is present, the current flowing through the parasitic diode and the freewheel diode 8 flows, and the first drive IC 4 and the freewheel diode 8 may be destroyed by the overcurrent. . Normally, the resistance of the choke coil 9 in FIG. 9 is set to a value much smaller than the resistance of the first solenoid valve 3 so as not to hinder the power supply from the power supply source 1. Therefore, suppression of the current passing through the parasitic diode and the return diode 8 due to the resistance of the choke coil 9 cannot be expected much, and the first drive I
An overcurrent will flow to C4 or the return diode 8. Therefore, the diode 2 is configured as a countermeasure against such a situation, and an overcurrent is prevented from flowing to the first driving IC 4 or the free wheel diode 8. However, in the present embodiment, since the second solenoid valve 5 is used in place of the choke coil 9, the solenoid valve 5 has a sufficient resistance equivalent to that of the solenoid valve 3, so that the Even if a current flows from the diode through the freewheeling diode 10, a sufficient current suppression can be expected due to the resistance value of the second solenoid valve 5. Therefore, the diode 2 in FIG. 9 can also be eliminated, and there is an effect that the cost can be reduced.

Next, a second embodiment will be described with reference to FIG. Note that components having the same functions and effects as those described above are denoted by the same reference numerals, and description thereof will be omitted. In this second embodiment, the first and second
The solenoid valves 3 and 5 are disposed in an actuator 20, and the CPU 7, the first and second drive ICs 4 and 6, and the return diode 10 are connected to an electronic control unit 21 (hereinafter referred to as EC).
U21). And this EC
The U21 and the actuator 20 are connected by wire harnesses 24 and 25.

Note that the first and second driving ICs 4 and 6 are EC
When implemented in U21, these first and second
Are connected in parallel to the driving ICs 4 and 6, respectively. These capacitors 22 and 23
Is configured to prevent the first and second drive ICs 4 and 6 from being destroyed by static electricity applied to the ECU 21.

When the capacitors 22 and 23 are provided as in this embodiment, the freewheeling diode 1 is installed in the ECU 21.
By forming 0, the following effects can be obtained in addition to the effects of the first embodiment. That is, noise generated by the inductance of the wire harnesses 24 and 25 can be suppressed. That is, when the first drive IC 4 is switched from OFF to ON, the first drive IC 4 side is grounded and the voltage at the point A decreases, so that the through current described in the first embodiment, that is, from the second solenoid valve 5 In addition to the through current passing through the freewheel diode 10, the electric charge stored in the capacitor 23 also passes through the freewheel diode 10 to form a through current. At this time, a change in the through current passing through the second solenoid valve 5 is suppressed by the inductance of the second solenoid valve 5, but the through current from the capacitor 23 is reduced by the action of the second solenoid valve 5. Because it does not receive a large current. For example, as shown in FIG. 3, when the freewheel diode 10 is disposed in the actuator 20, the through current from the capacitor 23 passes through the wire harness 25, the freewheel diode 10, and the wire harness 24, and the first It reaches the capacitor 22 on the drive IC 4 side. And the wire harness 25,
24, when a through current passes through the wire harness 24,
The occurrence of noise such as generation of a magnetic field is expected due to the inductance of 25. However, when the freewheeling diode 10 is mounted in the ECU 21 as in the second embodiment, since the through current from the capacitor 23 does not pass through the wire harnesses 24 and 25, noise such as magnetic field generation is generated. Can be prevented.

The same operation and effect as in the first embodiment can be obtained also in the configuration shown in FIG. 3, that is, when the free wheel diode 10 is disposed on the actuator 20 side. The present invention is not limited to the above-described embodiments, but can be variously modified as follows.

For example, as shown in FIG. 4, a free wheel transistor 40 may be used in place of the free wheel diode 10 configured in the above-described embodiments. The switching of the freewheeling transistor 40 may be performed by the CPU 7. That is,
When the first drive IC 4 is turned off, control may be performed so that power can be supplied from the first solenoid valve 3 to the second solenoid valve 5.

As shown in FIG. 5, a freewheeling MOS-FET 50 may be used instead of the freewheeling transistor 40 of FIG. When a MOS-FET is used, a parasitic diode (not shown) may be provided in this MOS-FET, and therefore, a diode 51 may be provided. As described above, even if the configurations shown in FIGS. 4 and 5 are adopted, the same or higher effects as those of the above-described embodiment can be obtained.

In FIG. 4, between the first and second solenoid valves 3 and 5 and the first and second drive ICs 4 and 6, in parallel with the freewheel transistor 40, the reverse of the freewheel transistor 30 is provided. A free-wheeling transistor (not shown) may be additionally connected so as to permit the energization.
The recirculation transistor 40 described above is configured to operate the first drive IC 4 in a state where the first solenoid valve 3 is duty-driven and the second solenoid valve 5 is not driven.
On the other hand, the return transistor (not shown) is turned on when the second drive IC is turned off in a state where the second solenoid valve 5 is duty-driven and the first solenoid valve 3 is not driven. Control by the CPU 7 as described above.

In the embodiments described above, the first solenoid valve 3 can be duty-driven and the second solenoid valve 5 is not duty-driven. However, if a reflux transistor (not shown) is provided, such a condition can be obtained. There is no restriction on the operation of the solenoid valve.
As shown in FIG. 6, the order of the electrical connection between the power supply source 1 and the ground point (ground) is changed from the power supply source 1 side.
The first and second drive ICs 4 and 6 may be replaced by first and second solenoid valves 3 and 5.

Further, the solenoid valve driving device in the embodiments described above may be applied to an anti-skid control device or a traction control device in a vehicle brake system. That is, the above-described first solenoid valve 3 may be applied to the pressure increasing control valve 50 in the brake system shown in FIG. 7 of the vehicle, and the second solenoid valve 5 may be applied to the pressure reducing control valve 51. . At this time, the pressure increase control valve 50 is configured as a valve that communicates and shuts off the flow of the brake fluid from the master cylinder 54 to the wheel cylinder 52 that generates the wheel braking force, and the pressure reduction control valve 51 is applied to the wheel cylinder 52. The valve is configured as a valve that controls the flow of the brake fluid to the reservoir 55 when the pressure of the brake fluid is reduced. The pressure-increasing control valve 50 is a normally open valve in which the valve element is in a communication state in a power supply cutoff state, and the pressure reduction control valve 51 is a normally closed valve in which the valve element is in a cutoff state in a power cutoff state. In normal anti-skid control, the pressure reducing control valve 5
No. 1 is duty-driven, and only the pressure increase control valve 51, which needs to execute slow pressure increase, that is, duty pressure increase when increasing the wheel cylinder pressure, is duty driven. The solenoid valve driving device described in the first embodiment or the second embodiment can be easily applied to the brake system that performs such anti-skid control. In the drive circuit using the freewheeling diode 10, when the second drive IC 6 is turned on, the first solenoid valve 3 is also energized.
In the brake device as shown in FIG.
(Power supply), that is, the wheel cylinder 52
When the pressure reduction control is performed, the pressure increase control valve 50
Is also turned on (energized). Therefore, even when the solenoid valve driving device having the return diode 10 which is a feature of the present invention is applied to the brake system shown in FIG. 7, the first solenoid valve 3 is used as the pressure increasing control valve, and the second solenoid is used as the second solenoid. The valve 5 can be configured as a pressure reduction control valve. Further, the solenoid valve driving device according to the present invention may be applied to the pressure increase control valve 56 and the pressure decrease control valve 57 corresponding to the wheel cylinder 53.
As described above, when the present invention is applied to the brake device of a vehicle having usually four or more wheels, the number of choke coils in the related art that can be eliminated increases in the entire brake system, and a large cost reduction can be realized. .

The solenoid valves 3 and 5 in the solenoid valve driving device described with reference to FIG. 4 or 5 may be applied to each valve in the brake system. Further, in the configuration including both the reflux transistor 40 and the reflux transistor (not shown) described in FIG. 4, both the pressure increase control valve 50 and the pressure decrease control valve 51 can be duty-driven.

FIG. 8 shows the components of the anti-skid control device shown in FIG. 7 (pressure increase control valves 50 and 56, pressure decrease control valve 51,
57 is a flowchart showing an example of a control method of the pump (57 and the pump). The flow shown in FIG. 8 can be appropriately applied to the first embodiment, the second embodiment, and the like. Hereinafter, the flowchart of FIG. 8 executed as needed for each wheel will be described. In step 100, an initial check of each flag and the like is executed in accordance with an ON operation of an ignition switch of the vehicle. In step 110, each wheel speed VW of each front right wheel, front left wheel, rear right wheel, rear left wheel is
The calculation is performed based on the output of a wheel speed sensor (not shown).
In step 120, the vehicle speed VB is calculated based on each wheel speed VW. In step 130, the wheel acceleration dVW of each wheel is calculated. In step 140, the slip ratio SW of each wheel is calculated.

In step 150, it is determined whether or not the slip ratio SW of the currently calculated wheel is greater than the first reference slip ratio KSW. If a negative determination is made here, it is determined that the wheels do not tend to lock, and the routine proceeds to step 160, where the ABS flag is set to F = 0, and the brake system is brought into the normal braking state. If an affirmative determination is made in step 150, the process proceeds to step 170, in which an ABS flag indicating that anti-skid control is being performed is set to F = ABS. In step 170, power is simultaneously supplied to a motor (not shown) for driving the pump, and the pump is turned on.

In step 180, the slip ratio SW of the currently controlled wheel is set to the second reference slip ratio MSW (SW> MS).
W) It is determined whether or not it is larger. If a negative determination is made here, the routine proceeds to step 190, where the pressure increase duty of the control target wheel is controlled. For example, assuming that the wheel including the wheel cylinder 52 is a control target wheel, this pressure increase duty control executes energization of the pressure increase control valve 50 by duty control and energizes the pressure decrease control valve 51. Instead, the valve position is set to the shut-off state as in the case of the passing brake state. In many cases, the process proceeds to step 190 after the second cycle after the anti-skid control is started and the control for increasing and decreasing the wheel cylinder pressure of the wheel to be controlled is performed once.

If an affirmative determination is made in step 180, the process proceeds to step 200, where it is determined whether or not the wheel acceleration dVW of the currently controlled wheel takes a negative value. That is, it is determined whether the wheel speed of the control target wheel is in the deceleration direction or the acceleration direction. If a negative determination is made here, the process proceeds to step 210, in which the wheel speed tends to return, and it is determined that the wheel cylinder pressure that has been accurately adjusted is being applied, and the brake fluid pressure applied to the wheel cylinder of the control target wheel is held and controlled. . For example, the pressure increase control valve 50 is continuously energized to shut off the valve position for a predetermined time, and the pressure decrease control valve 5
1 is not energized, and the valve position is set to the shut-off state.

If an affirmative determination is made in step 200, the process proceeds to step 220. In step 220,
The wheel acceleration dVW of the control target wheel is equal to the reference wheel acceleration KdV.
It is determined whether it is smaller than W (KdVW <0).
If an affirmative determination is made here, the routine proceeds to step 230, where the wheel cylinder pressure of the wheel to be controlled is reduced.
For example, the pressure increasing control valve 50 is continuously energized for a predetermined time, and the pressure reducing control valve 51 is continuously energized for a predetermined time. Thereby, when the wheel speed is in the deceleration direction by a predetermined amount or more when the locking tendency is strong, the wheel cylinder pressure is rapidly reduced. If a negative determination is made in step 220, the process proceeds to step 240, where pressure reduction duty control is performed on the control target wheel. This pressure reduction duty control is performed when it is not necessary to reduce the wheel cylinder pressure so rapidly. For example, the pressure reduction control valve is duty-controlled while not energizing the pressure increase control valve and keeping the valve position in the communicating state. Things. As a result, the pressure reduction and pressure increase of the wheel cylinder pressure are realized according to the duty control of the energization of the pressure reduction control valve, and the wheel cylinder pressure can be gradually reduced.

When the flow shown in FIG. 8 is executed,
In step 190, of the pair of pressure increase control valves and pressure reduction control valves that are configured for one wheel cylinder, only the pressure increase control valve is duty-controlled, and the pressure increase control valve is duty-controlled. During this time, the pressure reducing control valve is not energized and is turned off. Conversely, in step 240, of the pressure increase control valve and the pressure decrease control valve configured for one wheel cylinder, only the pressure decrease control valve is duty-controlled, and the pressure decrease control valve is duty-controlled. While the pressure increase control valve is not energized,
The state is set to FF. Therefore, in the anti-skid control device in which the control shown in FIG. 8 is performed, FIG.
And the first and second solenoid valves 3, 5 and the first,
A free-wheeling transistor (not shown) is additionally provided between the second driving ICs 4 and 6 in parallel with the free-wheeling transistor 40 so as to allow current flowing in the opposite direction to the free-wheeling transistor. If the control is performed in accordance with the shift, the above-described functions and effects are exhibited. As a specific example of the control of each of the freewheeling transistors, control for permitting energization of the freewheeling transistor 40 is performed in step 190, and control for permitting energization of a freewheeling transistor (not shown) that allows current to flow in the opposite direction to the freewheeling transistor 40 , 240 may be executed.

Further, in the flow of FIG.
If the flow proceeds to step 230 when affirmative determination is made in step 200, omitting 0 and step 240, if the pressure increase control valve and the pressure decrease control valve of the pair of pressure increase control valves and Only the pressure control valve is duty-controlled, during which time the pressure reducing control valve is not energized, and the solenoid itself of the pressure reducing control valve plays the role of a choke coil.
6 can be applied.

Further, the solenoid valve driving device in the above-described embodiments is not only a brake system but also a solenoid valve driving device.
For example, the same effect can be obtained even when applied to driving of an air valve configured in an air conditioner or the like.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a circuit configuration diagram showing another embodiment of the present invention.

FIG. 4 is a circuit diagram showing another embodiment of the present invention.

FIG. 5 is a circuit diagram showing another embodiment of the present invention.

FIG. 6 is a circuit diagram showing another embodiment of the present invention.

FIG. 7 is a block diagram showing a system to which the solenoid valve driving device according to the present invention is applied.

FIG. 8 is a flowchart illustrating an example of a control flow of each component of the anti-skid control device to which the present invention has been applied.

FIG. 9 is a circuit diagram showing a conventional technique.

[Description of Signs] 1 Power supply source 3 First solenoid valve 4 First drive IC 5 Second solenoid valve 6 Second drive IC 7 CPU 10 Reflux diode 20 Actuator 21 ECU 24, 25 Wire harness 40 Reflux transistor 50 Freewheeling MOS-FET

Claims (11)

[Claims] 1. A first solenoid valve driven by receiving a supply current from a power supply source, and supplying and supplying a supply current to the first solenoid valve.
A first switching unit that cuts off, a supply current from the power supply source, a second solenoid valve connected in parallel with the first solenoid valve, and a supply current to the second solenoid valve.・
A second switching means for interrupting, a control means for duty-controlling the first switching means to supply a supply current, and controlling the second switching means to be in an interrupted state during the control period; The other end is connected between the first switching means and the first solenoid valve and the other end is connected between the second switching means and the second solenoid valve,
A solenoid valve driving device, comprising: a bypass path including an element having a characteristic that a direction in which a current flows between both ends of the connection does not substantially impede a return current in the first solenoid valve. 2. The electronic control apparatus according to claim 1, wherein said first and second switching means and said control means are incorporated in an electronic control unit.
2. The solenoid valve driving device according to claim 1, wherein a capacitor is connected in parallel with the switching means, and the bypass path is formed in the electronic control. 3. The first solenoid valve is used as a pressure increasing control valve for permitting / cutting off the flow of brake fluid into a wheel cylinder in order to optimally maintain a slip state during braking of the vehicle. 3. The solenoid valve according to claim 1, wherein the solenoid valve is used as a pressure-reducing control valve that permits and shuts off the outflow of brake fluid from a wheel cylinder so as to optimally maintain a slip state during braking of the vehicle. Solenoid valve drive. 4. The device according to claim 1, wherein the element configured in the bypass path includes a diode that substantially allows only conduction in a direction that does not hinder the return current on the first solenoid valve side. 4. The solenoid valve driving device according to claim 1, wherein: 5. The device according to claim 1, wherein the element configured in the bypass path is connected to the second solenoid valve from a side of the first solenoid valve.
4. The solenoid valve driving device according to claim 1, further comprising a diode substantially allowing only conduction to the solenoid valve side of the solenoid valve. 6. A first solenoid valve driven by receiving a supply current from a power supply source, and supplying and supplying a supply current to the first solenoid valve.
A first switching unit that cuts off, a supply current from the power supply source, a second solenoid valve connected in parallel with the first solenoid valve, and a supply current to the second solenoid valve.・
A second switching means for interrupting, a control means for duty-controlling the first switching means to supply a supply current, and controlling the second switching means to be in an interrupted state during the control period; The other end is connected between the first switching means and the first solenoid valve and the other end is connected between the second switching means and the second solenoid valve,
A bypass path including an element having a characteristic that a direction in which a current flows between both ends of the connection is substantially from the first switching means side end to the second switching means side end. Characteristic solenoid valve drive. 7. A first solenoid valve driven by receiving a supply current from a power supply source, and supplying and supplying a supply current to the first solenoid valve.
A first switching unit that cuts off, a supply current from the power supply source, a second solenoid valve connected in parallel with the first solenoid valve, and a supply current to the second solenoid valve.・
A second switching means for interrupting, a control means for performing duty control on one of the first switching means and the second switching means and setting the other switching means in an interrupted state, The other end is connected between the switching means and the first solenoid valve and the other end is connected between the second switching means and the second solenoid valve,
A bypass path including a determination unit that determines a direction in which a current flows between both ends of the connection depending on which of the first and second switching units is duty-controlled by the control unit. . 8. The first and second switching means and the control means are incorporated in an electronic control device, the bypass path is formed in the electronic control device, and the first solenoid valve and The second solenoid valve is electrically connected by a wire harness extending from the electronic control device, and is disposed on a vehicle actuator disposed separately from the electronic control device. The solenoid valve driving device according to claim 2, wherein: 9. A solenoid provided with anti-skid control means for controlling a brake fluid pressure applied to each wheel cylinder by connecting / disconnecting a hydraulic circuit by a solenoid valve to adjust a slip state of a wheel during braking of a vehicle. In the valve drive device, the flow state of the brake fluid between the master cylinder and the wheel cylinder is switched between communication and cutoff, and the supply current from the power supply source is controlled so as to control the increase in the brake fluid pressure applied to the wheel cylinder. A first solenoid valve driven in response to the current, and supplying and supplying a supply current to the first solenoid valve.
First switching means for shutting off, and switching the flow state of the brake fluid between the wheel cylinder and the reservoir for storing the brake fluid for the reduced pressure from the wheel cylinder to communication / interruption, thereby applying a brake to the wheel cylinder. A supply current is supplied from the power supply source so as to control the reduction of the fluid pressure, and a supply current is supplied to the second solenoid valve connected in parallel with the first solenoid valve, and the supply current to the second solenoid valve.・
A second switching means for interrupting, a control means for duty-controlling the first switching means to supply a supply current, and controlling the second switching means to be in an interrupted state during the control period; The other end is connected between the first switching means and the first solenoid valve and the other end is connected between the second switching means and the second solenoid valve,
A bypass path including an element having a characteristic that a direction in which a current flows between both ends of the connection is substantially from the first switching means side end to the second switching means side end. Characteristic solenoid valve drive. 10. When the first switching means controls supply / disconnection of a supply current to the first solenoid valve, the second switching means supplies a signal to the second solenoid valve. The solenoid valve driving device according to any one of claims 1 to 9, wherein energization is not performed. 11. When the first switching means performs duty control of a current supplied to the first solenoid valve, the second switching means inhibits energization of the second solenoid valve. When the second switching means is performing duty control on the current supplied to the second solenoid valve, the first switching means inhibits energization of the first solenoid valve. The solenoid valve driving device according to claim 7, wherein: