JP2006097806A - Solenoid valve control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve control device for preventing a member as part of a valve part from being in a constantly one-direction magnetized condition. <P>SOLUTION: The solenoid valve control device comprises an electromagnet for attracting a piston (a valve element) to one side independently of the energizing direction of a coil 8. Herein, control means (a H-bridge circuit consisting of power MOSFETs 21-24 and a control circuit 25 for controlling it to change the energizing direction of the coil 8 at starting system, e.g.) is provided for alternately switching the energizing direction of the coil 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for a solenoid valve (electromagnetic valve) using an electromagnet that attracts a valve body in one direction regardless of the direction of energization of the coil, and a problem caused by the members constituting the valve portion being magnetized. It is related with the technology to prevent.

  For example, in a transmission of an automobile, a solenoid valve is used to control the hydraulic pressure. As such a solenoid valve, for example, a linear solenoid valve (valve unit) described in, for example, Patent Documents 1 to 5 has been conventionally used. In which the degree of opening of the coil is changed in accordance with the energization amount of the coil is known. Here, the “valve part” is a part in which the opening degree or the open / closed state is adjusted by the valve body in the communication part between the inflow side port and the outflow side port of the solenoid valve. , Spool and sleeve).

JP 2003-28335 A JP 2003-314732 A JP-A-7-224963 JP 2001-132865 A JP-A-5-106756

  By the way, in the conventional solenoid valve described above, the energization direction of the coil constituting the electromagnet is usually always constant. Therefore, a valve body provided integrally with a movable core (plunger) driven by electromagnetic force, or a member constituting a valve seat facing the valve body with a slight gap (that is, a member constituting the valve portion) ) Is formed of a magnetic material such as iron, these members are unidirectionally magnetized. And when the member which comprises a valve part becomes magnetized in this way, so-called contamination (micro solid foreign substance which exists in a fluid) is adsorbed by the member which comprises a valve part, and, thereby, a valve part It has been found by the inventors' research that there is a risk of interfering with the operation and disturbing the operation. For example, in a state where the opening degree of the valve portion is large, contamination remains in the valve portion, and thereafter, the operation of the valve body in the direction of reducing the opening degree (that is, the operation of the plunger) is obstructed by the contamination. I found out that there is a risk. For this reason, in order to remove the contamination, an attempt was made to provide a sieve (mesh), but this would increase the cost.

In exceptional cases, in Patent Document 1, a permanent magnet and an electromagnet are used, and the energization direction of the electromagnet coil is switched in accordance with the driving direction of the valve body, so that the forward / backward movement of the valve body is electromagnetic in any direction. A linear solenoid valve driven by force (which uses a spring complementarily for return operation) is disclosed. In this valve, the polarity of the electromagnet is controlled to be reversed according to the driving direction of the valve body (direction of electromagnetic force). However, depending on the equipment used, the driving direction of the valve body may be constant. In this case, the polarity of the electromagnet is substantially constant. Further, the direction of the magnetic field by the permanent magnet is always constant. For this reason, the members such as the valve body are steadily unidirectionally magnetized, and the above-described contamination adsorption may occur, and the above-described measures are required.
Therefore, the present invention is a control device for a solenoid valve of a type using an electromagnet that attracts a valve body to one side regardless of the energization direction of the coil (not a type using a permanent magnet as in Patent Document 1 described above). Thus, an object of the present invention is to provide a control device in which the members constituting the valve portion do not constantly become unidirectionally magnetized.

The solenoid valve control device of the present application is configured such that an inflow side port into which a fluid flows, an outflow side port from which a fluid flows out, and a forward and backward movement in a predetermined direction. A valve body that changes an opening degree or an open / closed state of the communication portion; and a driving unit that drives the valve body in the predetermined direction, and the driving unit moves the valve body in the predetermined direction regardless of the energization direction of a coil. In the solenoid valve control device comprising an electromagnet that attracts to one side of
Control means for alternately switching energization directions of coils constituting the electromagnet is provided.

A more preferable aspect of the present invention is an aspect in which the solenoid valve is a linear solenoid valve that changes the degree of opening according to the energization amount of the coil.
Further, as described in claim 3, it is preferable that the control means switches the energization direction when starting or stopping a device or facility provided with the solenoid valve.

In the solenoid valve control device of the present application, the energizing directions of the coils constituting the electromagnet are alternately switched. Therefore, even when the members constituting the valve portion are formed of a magnetic material such as iron, these members are stationary. It does not become unidirectionally magnetized. That is, by switching the coil energization direction, the direction of magnetism is also switched, and the previous magnetism before the switching is demagnetized, so that it is hardly magnetized or is extremely weak even when magnetized. For this reason, the above-mentioned contamination adherence hardly occurs, and the possibility of occurrence of defects due to the contamination adherence can be greatly reduced.
In particular, in the case of the linear solenoid valve according to the second aspect, since contamination easily remains in the valve portion, the effect of preventing contamination adherence is remarkable. Incidentally, for example, in the case of a duty solenoid valve, the valve body repeatedly opens and closes at a predetermined cycle. The possibility of malfunctions due to is basically low.

Further, as described in claim 3, there is the following advantage when the energization direction of the coil is switched at the time of starting or stopping the equipment or equipment provided with the solenoid valve. That is, adverse effects caused by temporarily switching the energization direction of the coil during the operation of the device or facility and temporarily stopping the solenoid valve will be avoided. In other words, when switching the energization direction of the coil, the coil is always in a non-energized state (zero current), so if the coil should be energized at that time, the function of the solenoid valve is temporarily lost. However, if the switching is executed at the time of starting or stopping the device or equipment, such a harmful effect can be surely avoided. In addition, as the time of starting or stopping the device or facility, for example, in the case of an automobile, there may be a time when the ignition switch is turned on or off.
In the solenoid valve of the present application, the driving means for driving the valve body includes an electromagnet that attracts the valve body to one side in a predetermined direction regardless of the energization direction of the coil. For this reason, even if the energization direction of the coil is switched, the operation direction of the valve body is constant, and a constant function as a solenoid valve can always be exhibited.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a circuit diagram showing a control device for driving and controlling a solenoid valve, FIG. 2 is a flowchart showing control processing of the solenoid valve, and FIG. 3 is a cross-sectional view showing an example of a solenoid valve body.
First, the solenoid valve body will be described. As shown in FIG. 3, the solenoid valve 1 of this example includes a body 2 that is a housing that covers an outer surface, a plunger pin 3 that is disposed on the inner central axis of the body 2 so as to be movable up and down, and the plunger Plunger 4 (movable side yoke made of a magnetic material such as free-cutting steel) fixed to the outer periphery of the center of the pin 3, piston 5 (valve element) fixed to the outer periphery of the lower end of the plunger pin 3, and the plunger pin 3 is arranged on the outer peripheral side of the fixed side core 6 (fixed side yoke made of a magnetic material such as free-cutting steel) disposed on the outer peripheral side of the upper end portion 3 and fixed to the body 2. A bobbin 7 installed and fixed to the body 2, a coil 8 wound around the outer periphery of the bobbin 7, and an outer periphery of the plunger pin 3, the plunger 4 and the fixed core 6 (strictly, a slide bearing described later) 12) A valve seat fixed to a coil-shaped return spring 9 (biasing means) for biasing the movable portion (plunger pin 3, plunger 4 and piston 5) downward and a connecting portion 2a formed at the lower end of the body 2. And a terminal portion 11 for connecting the coil 8 to the circuit of the control device.
In addition, the whole movable part which consists of the plunger pin 3, the plunger 4, and the piston 5 may be called a plunger, and the plunger pin 3 or the piston 5 may be called a plunger.

Here, the body 2 has a connecting portion 2a to a hydraulic circuit or the like at the lower end portion, and a through-hole extending from the lower end surface of the connecting portion 2a to the inside and penetrating to the upper end surface forms the inflow side port 2b. Moreover, the opening formed in the upper end side outer periphery of the connection part 2a comprises the outflow side port 2c.
The seal member 10 is a donut-shaped member fixed to the upper inside of the through hole (inflow side port 2b) of the connecting portion 2a.
The lower end surface of the piston 5 can be joined to or opposed to the upper surface of the seal member 10 so that the upper surface opening of the seal member 10 can be closed. This is a communicating portion of the inflow side port 2b and the outflow side port 2c, and the opening degree and the open / closed state are variable.
Further, the upper end of the plunger pin 3 can be moved up and down with respect to the stationary core 6 by the slide bearing 12, and the piston 5 can be moved up and down with respect to the body 2 by the slide bearing 13. The movable part composed of the plunger pin 3, the plunger 4 and the piston 5 can move up and down with respect to the fixed side of the body 2 or the like.

In the solenoid valve 1 configured as described above, in a non-energized state in which no voltage is applied to the coil 8, as long as the pressure of the fluid applied to the inflow side port 2 b (for example, hydraulic pressure) is smaller than the urging force equivalent to the return spring 9. The piston 5 is joined to the upper surface of the seal member 10 by the urging force of the return spring 9 and moves in a direction (in this case, downward) to close the inflow side port 2b with respect to the outflow side port 2c, and the valve portion is closed. It becomes a state. When the coil 8 is energized such that a voltage higher than a predetermined voltage is applied, the attractive force of the electromagnet composed of the coil 8, the movable core (plunger 4), and the fixed core 6 opposes the biasing force of the return spring 9. Acting in the direction, the piston 5 moves in a direction (in this case, upward) to open the inflow side port 2b with respect to the outflow side port 2c, and the valve portion is opened.
The opening degree of the valve portion in this energized state is the above-mentioned movable in which the force due to the pressure of the fluid applied to the inflow side port 2b, the attraction force of the electromagnet, and the urging force of the return spring 9 facing them are balanced. It depends on the position of the part. Therefore, by adjusting the current flowing through the coil 8 in the energized state (that is, the attractive force of the electromagnet), the opening degree of the valve portion can be controlled, and the solenoid valve 1 can function as a linear solenoid valve. it can.
At this time, the direction in which the movable part is attracted by the electromagnet is always constant (in this case, always upward) regardless of the voltage application direction (the energization direction of the coil 8). However, the positions of the N pole and the S pole of the electromagnet are naturally upside down depending on the energization direction of the coil.

  The solenoid valve 1 exemplified here is used for adjusting the line pressure of an automatic transmission for a vehicle, and is a hydraulic circuit connected to an inflow side port 2b of a connecting portion 2a (the source of a hydraulic pump (not shown)). The pressure of the circuit line to which the pressure is supplied can be adjusted within the range of the original pressure. When the piston 5 is raised and the inflow side port 2b is open with respect to the outflow side boat 2c, a part of the oil in the hydraulic circuit is transferred from the inflow side port 2b to the outflow side port as shown by an arrow in FIG. It flows out to 2c and is discharged out of the hydraulic circuit. For this reason, if the rising position of the piston 5 (that is, the opening degree of the valve portion) is changed, the pressure of the inflow side port 2b (that is, the pressure of the hydraulic circuit) changes accordingly.

Next, the configuration of the solenoid valve control device 20 will be described.
As shown in FIG. 1, the solenoid valve control device 20 of this example includes four power MOSFETs 21 to 24 connected in an H-bridge shape to the coil 8 and the power supply line of the solenoid valve 1, and these power MOSFETs 21 to 21. And a control circuit 25 for controlling the drive of the motor 24. The voltage Ving applied to the high-potential-side power supply line 26 is obtained by, for example, transforming or stabilizing the output voltage of the vehicle battery as necessary, and is turned on and off in synchronization with the ignition switch of the vehicle, for example. It has a configuration.
The control circuit 25 is a circuit including a microcomputer and a transistor for driving the power MOSFETs 21 to 24 under the control of the microcomputer. The control circuit 25 controls the driving of the coil 8 (that is, shown in FIG. 2). , Control of the solenoid valve 1). In this case, when the solenoid valve 1 is energized, one of the FETs connected to the high potential power supply line 26 (power MOSFET 21) and one of the FETs connected to the low potential power supply line 27 (ground line). Either the other (power MOSFET 24) is turned on, or the other FET (power MOSFET 22) connected to the high-potential-side power line 26 and one FET (power MOSFET 23) connected to the low-potential-side power line 27 Turn on. That is, one of the combinations of FETs at the diagonal positions is turned on, and the other is turned off. This makes it possible to energize the coil 8 with the energization direction set to any one.

Hereinafter, the microcomputer control process of the control circuit 25 will be described with reference to FIG.
For example, when an ignition switch of an automobile is turned on (usually an operation of inserting and turning a key called an ignition key) and a system including an automatic transmission is started, the control circuit 25 starts a routine shown in FIG. First, in step S1, the combination of the FETs to be driven (FET 21 and FET 24 or FET 22 and FET 23) is set opposite to that before key-off. That is, a different one from the combination of FETs stored in step S4 described later is set. If there is no such storage, any combination set in advance is set.
After step S1, the process proceeds to step S2, and the combination FET set in step S1 is driven to start control of the solenoid valve 1. That is, when it is necessary to perform a pressure adjustment operation by the solenoid valve 1, the set combination of FETs (FET21 and FET24, or FET22 and FET23) is turned on, and the solenoid valve 1 is turned on. To do. At this time, control of the amount of current (control of the opening degree of the solenoid valve 1) is realized, for example, by PWM control of one or both of the FETs to be driven with a duty ratio corresponding to the target current.

During the above control, it is determined in step S3 whether or not the ignition switch has been turned off. If the ignition switch has been turned off, the process proceeds to step S4.
In step S4, before the microcomputer shuts down, the combination of FETs driven in the control executed in step S2 is stored, and then the processing of this routine is terminated.

According to the solenoid valve control device of the present example described above, the energizing direction of the coil 8 constituting the electromagnet is alternately switched every time the ignition switch is operated. Even when the sealing member 10) is made of a magnetic material such as iron, these members do not steadily become magnetized in one direction. That is, by switching the coil energization direction, the direction of magnetism (the vertical relationship between the N pole and the S pole) is also switched, and the previous magnetism before the switching is demagnetized, so that the magnetism is steadily almost magnetized. Even if you take it, it will be extremely weak. For this reason, the above-mentioned contamination adherence hardly occurs, and the possibility of occurrence of defects due to the contamination adherence can be greatly reduced.
In particular, this example is a linear solenoid valve, and since contamination easily enters the valve portion, the effect of preventing contamination adherence is remarkable.

In addition, since the present embodiment is a mode in which the energization direction of the coil is switched at the time of starting or stopping the equipment or equipment provided with the solenoid valve 1 (for example, when operating the ignition switch of the automobile), there are the following advantages. . That is, switching of the energizing direction of the coil 8 is performed while the device or facility is operating (for example, while the vehicle is running), and adverse effects due to the temporary malfunction of the solenoid valve 1 can be avoided. That is, when the direction of energization of the coil 8 is switched, the coil 8 is always in a non-energized state (zero current) for a moment. Therefore, if the coil 8 is to be energized at that time, the solenoid valve 1 temporarily. However, if switching is performed at the time of starting or stopping the device or equipment, such a problem can be surely avoided.
In the solenoid valve 1 of this example, the driving means for driving the valve body (piston 5) is composed of an electromagnet that attracts the valve body to one side in a predetermined direction regardless of the energization direction of the coil 8. For this reason, even if the energization direction of the coil 8 is switched, the operation direction of the valve body is constant, and a constant function as a solenoid valve can always be exhibited.

The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.
For example, in the above-described embodiment, a solenoid valve of a type in which the plunger is attracted in a direction to open the valve part by electromagnetic force is illustrated, but the solenoid valve is a type in which the plunger is attracted in a direction to close the valve part by electromagnetic force. May be.
FIG. 4 is a view showing a solenoid valve 31 of this type. Hereinafter, the solenoid valve 31 will be described. In the case of this solenoid valve 31, no return spring is required.

  The solenoid valve 31 is fixed to the outer periphery of a body 32 that is a casing covering the outer surface, a plunger pin 33 that is disposed on the inner central axis of the body 32 so as to be movable up and down, and an upper end portion of the plunger pin 33. Plunger 34 (movable side yoke made of a magnetic material such as free-cutting steel), piston 35 (valve element) provided on the lower coaxial line of plunger pin 33 so as to move up and down, and the outer peripheral side of the lower end of plunger pin 33 The fixed side core 36 (fixed side yoke made of a magnetic material such as free-cutting steel) fixed to the body 32 and the plunger 34 and the fixed side core 36 are arranged on the outer peripheral side and fixed to the body 32. A bobbin 37, a coil 38 wound around the outer periphery of the bobbin 37, a seal member 40 which is fixed to a connecting portion 32a formed at the lower end of the body 32 and forms a valve seat, And a terminal portion 41 for connection to the circuit 38 of the control device.

Here, the body 32 has a connection portion 32a to a hydraulic circuit or the like at the lower end portion, and a through-hole extending from the lower end surface of the connection portion 32a to the upper inside and penetrating to the upper end surface forms an inflow side port 32b. Moreover, the opening formed in the upper end side outer periphery of the connection part 32a comprises the outflow side port 32c.
The seal member 40 is a donut-shaped member fixed to the upper inside of the through hole (inflow side port 32b) of the connection portion 32a.
The piston 35 can be moved up and down with respect to the stationary core 36 by the slide bearing 42, and the lower end surface of the piston 35 can close the upper surface opening of the seal member 40. Can be joined to or opposed to each other, and together with the seal member 40, constitutes a valve portion (a communication portion between the inflow side port 32b and the outflow side port 32c, and a portion whose opening degree and open / close state are variable). The piston 35 in this case is separate from the plunger pin 33 (not attached integrally), but is driven downward when the upper surface is pushed by the lower surface of the plunger pin 33.
The plunger pin 33 can be moved up and down with respect to the stationary core 36 by the slide bearing 43, and the plunger 34 can be moved up and down with respect to the bobbin 37 by the slide bearing 44. A movable part including the pin 33, the plunger 34, and the piston 35 can move up and down with respect to the fixed side of the body 32 or the like.

  In the solenoid valve 31 configured as described above, in a non-energized state where no voltage is applied to the coil 38, the piston 35 changes the inflow side port 32b to the outflow side port 32c by the pressure of the fluid applied to the inflow side port 32b. On the other hand, it moves in the opening direction (in this case, upward), and the valve portion is in a free open state that opens according to the fluid pressure. When a predetermined voltage is applied to the coil 38, the attractive force of the electromagnet composed of the coil 38, the movable side core (plunger 34), and the fixed side core 36 acts in a direction to lower the plunger pin 33 downward. Then, the piston 35 pushed by the plunger pin 33 joins the upper surface of the seal member 40 and is driven in a direction (in this case, downward) to close the inflow side port 32b with respect to the outflow side port 32c, and the valve portion is adjusted. Pressure state.

The pressure regulation state here is a state in which the opening degree of the valve portion can be controlled by adjusting the current flowing through the coil 38 and the solenoid valve 31 can function as a linear solenoid valve. The degree of opening of the valve portion in the energized state is determined by the position of the piston 35 where the force due to the pressure of the fluid applied to the inflow side port 32b and the attractive force of the electromagnet opposed to the force are balanced. Therefore, by adjusting the current flowing through the coil 38 in the energized state (that is, the attractive force of the electromagnet), the opening degree of the valve portion can be controlled, and the solenoid valve 1 can function as a linear solenoid valve. it can.
At this time, the direction in which the movable part (plunger pin 33, piston 35, etc.) is attracted by the electromagnet is always constant (in this case, always downward) regardless of the voltage application direction (the energization direction of the coil 38). . However, the positions of the N pole and the S pole of the electromagnet are naturally upside down depending on the energization direction of the coil.
For this reason, the above-described control device 20 can be applied to the solenoid valve 31 to achieve the same effects as the above-described embodiment.

  In the embodiment described above, as a solenoid valve to which the present invention is applied, a poppet type solenoid valve as shown in FIGS. 3 and 4 is exemplified. However, as described in Patent Documents 2 and 4 described above, The present invention can also be applied to a spool type solenoid valve. Even in this case, even if the spool (valve body) and the sleeve (valve seat) are magnetic bodies, they can be prevented from being constantly magnetized in a certain direction, and contamination can be caused between the spool and the sleeve. The possibility can be greatly reduced.

It is a circuit diagram which shows the control apparatus of a solenoid valve. It is a flowchart which shows the control processing of a solenoid valve. It is sectional drawing which shows an example of a solenoid valve main body. It is sectional drawing which shows the other example of a solenoid valve main body.

Explanation of symbols

1, 31 Solenoid valve 2b, 32b Inlet side port 2c, 32c Outlet side port 4, 34 Plunger (electromagnet)
5, 35 Piston (valve)
6, 36 Fixed core (electromagnet)
8, 38 Coil (electromagnet)
21-24 Power MOSFET (control means)
25 Control circuit (control means)

Claims (3)

An inflow side port into which the fluid flows in, an outflow side port from which the fluid flows out, and a forward / backward movement in a predetermined direction are possible, and the degree of opening or the open / close state of the communication portion between the inflow side port and the outflow side port is determined depending A valve body to be changed; and a driving means for driving the valve body in the predetermined direction. The driving means includes an electromagnet that attracts the valve body to one side in the predetermined direction regardless of the energization direction of the coil. In the solenoid valve control device,
A solenoid valve control device comprising control means for alternately switching energizing directions of coils constituting the electromagnet. The solenoid valve control device according to claim 1, wherein the solenoid valve is a linear solenoid valve that changes the degree of opening in accordance with an energization amount of the coil. The control device for a solenoid valve according to claim 1 or 2, wherein the control means switches the energization direction when a device or facility provided with the solenoid valve is started or stopped.

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