JP7461017B2 - Methods, systems, devices, programs, recording media, and proportional solenoid valves for controlling proportional solenoid valves - Google Patents

Description

The present disclosure relates to, for example, a proportional solenoid valve used in a fuel gas control valve, and its control technology.

2. Description of the Related Art Valves are used to control fluids such as fuel gas, and known as proportional solenoid valves that control valve opening by energizing a solenoid.
For example, control based on a PWM (pulse width modulation) method is used to control the opening of the proportional solenoid valve.
Regarding the PWM control of the proportional solenoid valve, a suspension control device is known in which the period of dither vibration is adjusted or decreased regardless of the magnitude of the energizing current (Patent Document 1).

Japanese Patent Application Publication No. 10-258625

In a proportional solenoid valve, a difference occurs between the drive current when the drive current flowing through the solenoid is increased to reach a specific valve opening and the drive current when the drive current is decreased to reach a specific valve opening. Also, a difference occurs between the valve opening when the drive current is increased to reach a specific drive current and the valve opening when the drive current is decreased to reach a specific drive current. In other words, there is hysteresis between the drive current and the valve opening, and even with the same drive current, the valve opening differs depending on the direction of increase or decrease, and even with the same valve opening, the drive current differs.
When a proportional solenoid valve with such hysteresis characteristics is used, it affects the control of fluids such as fuel gas, and reduces the reliability of the control characteristics. The cause of this hysteresis is the magnetization characteristics of the proportional solenoid valve, particularly the residual magnetism. When using a magnetic material, the effect of this residual magnetism cannot be ignored.

When considering residual magnetism and solenoid excitation, there is an issue that when the proportional solenoid is excited in the same direction as the residual magnetism, the residual magnetism is added to the generated magnetic force, whereas when the proportional solenoid is excited in the opposite direction to the residual magnetism, part of the generated magnetic force is offset by the residual magnetism.
To address this issue, the inventor discovered that the effects of residual magnetism can be reduced by generating an alternating magnetic field in a proportional solenoid, and that the desired valve opening can be obtained by adjusting the level of the drive current that generates such an alternating magnetic field.
In view of the above problems and findings, an object of the present disclosure is to obtain a desired valve opening degree by controlling the level of the drive current while avoiding the effects of residual magnetism by generating an alternating magnetic field in a proportional solenoid.

In order to achieve the above object, according to one aspect of a control method for a proportional solenoid valve disclosed herein, there is provided a control method for a proportional solenoid valve in which a valve opening is controlled by exciting a proportional solenoid, the control method including the steps of: generating a drive current for exciting the proportional solenoid ; generating a forward pulse including a polarity reversing section for reversing the polarity of the reverse drive current to a forward direction; generating a reverse pulse including a polarity reversing section for reversing the polarity of the forward drive current to the reverse direction; reversing the polarity of the drive current at a period faster than the movement of a valve body by using the forward pulse and the reverse pulse ; and controlling the valve opening based on the current level of the drive current.
This method of controlling a proportional solenoid valve may include the steps of controlling a duty ratio of the forward pulse excluding the polarity reversal portion, and controlling a duty ratio of the reverse pulse excluding the polarity reversal portion.

In order to achieve the above object, according to one aspect of the proportional solenoid valve system of the present disclosure, a proportional solenoid valve whose valve opening degree is controlled by energization of the proportional solenoid, and a drive current that excites the proportional solenoid are generated, Generates a forward pulse including a drive unit that causes the drive current to flow through the proportional solenoid, and a polarity inversion unit that inverts the polarity of the drive current in the opposite direction to the forward direction, and reverses the polarity of the drive current in the forward direction. a logic circuit that generates a reverse direction pulse including a polarity reversal section that reverses the polarity of the driving current, and a logic circuit that generates a reverse direction pulse that reverses the polarity of the drive current at a cycle faster than the movement of the valve body by using the forward direction pulse and the reverse direction pulse ; and a control section that controls the valve opening depending on the current level of the drive current.
This proportional solenoid valve system may further include a pulse width control section that controls the duty ratio of the forward direction pulse excluding the polarity inversion section or the duty ratio of the reverse direction pulse excluding the polarity inversion section.

In order to achieve the above object, according to one aspect of the proportional solenoid valve control device of the present disclosure, a drive current is generated to excite a proportional solenoid that controls the valve opening degree by excitation, and the drive current is applied to the proportional solenoid. and a polarity inversion unit that generates a forward pulse and inverts the polarity of the drive current in the forward direction. a logic circuit that generates a reverse direction pulse, and uses the forward direction pulse and the reverse direction pulse to reverse the polarity of the drive current at a cycle faster than the movement of the valve body, and to reverse the polarity of the drive current according to the current level of the drive current. and a control section that controls the opening degree.
In this proportional solenoid valve control device, the control unit further includes a pulse width for controlling the duty ratio of the forward pulse excluding the polarity reversal portion, or the duty ratio of the reverse pulse excluding the polarity reversal portion. and a control unit.

In order to achieve the above-mentioned object, according to one aspect of the program of the present disclosure, there is provided a program implemented by a computer, which realizes the following functions: generating control information for generating a drive current that excites a proportional solenoid ; generating a forward pulse including a polarity reversal section that reverses the polarity of the reverse drive current to a forward direction; generating a reverse pulse including a polarity reversal section that reverses the polarity of the forward drive current to the reverse direction; generating control information that uses the forward pulse and the reverse pulse to reverse the polarity of the drive current at a period faster than the movement of the valve body; and generating control information that controls the valve opening degree based on the current level of the drive current.
This program may further cause the computer to realize a function of controlling the duty ratio of the forward pulse excluding the polarity reversal portion, and a function of controlling the duty ratio of the reverse pulse excluding the polarity reversal portion.

To achieve the above object, according to one aspect of the recording medium of the present disclosure, the program is stored.

To achieve the above object, according to one aspect of the proportional solenoid valve of the present disclosure, there is provided a valve mechanism controlled by excitation of a proportional solenoid, a drive section that causes a drive current to flow through the proportional solenoid, and a drive current that flows in the opposite direction . a logic circuit that generates a forward pulse including a polarity inversion section that inverts the polarity of the drive current in the forward direction; Using the forward direction pulse and the reverse direction pulse, the polarity of the drive current is reversed at a cycle faster than the movement of the valve body to cancel residual magnetism, and the valve opening degree is adjusted according to the current level of the drive current. and a control section.
In order to achieve the above object, according to one aspect of the proportional solenoid valve of the present disclosure, a valve mechanism, a proportional solenoid that controls the valve mechanism by excitation, and a drive current that excites the proportional solenoid are generated and the drive current is generated. Generating a forward pulse including a driving part that causes current to flow through the proportional solenoid and a polarity reversing part that reverses the polarity of the driving current in the opposite direction to the forward direction, and inverts the polarity of the driving current in the forward direction to the opposite direction. a logic circuit that generates a reverse direction pulse including a polarity reversal unit that causes the drive current to invert the polarity of the drive current at a cycle faster than the movement of the valve body using the forward direction pulse and the reverse direction pulse ; and a control section that controls the valve opening depending on the current level of the valve.
In this proportional solenoid valve, the control section further includes a pulse width control section that controls the duty ratio of the forward direction pulse excluding the polarity inversion section or the duty ratio of the reverse direction pulse excluding the polarity inversion section. may include.

According to the present disclosure, any of the following effects can be obtained.
(1) By reversing the polarity of the drive current passed through the solenoid, an alternating magnetic field is generated in the solenoid, and this alternating magnetic field can cancel out residual magnetism, thereby reducing hysteresis caused by residual magnetism.
(2) The valve opening degree can be controlled by the level of the drive current without being affected by residual magnetism.
(3) It is possible to reduce the difference between the drive current when the drive current flowing through the solenoid is increased to control it to a specific valve opening and the drive current when the drive current is decreased to control it to a specific valve opening.
(4) It is possible to reduce the difference between the valve opening degree when the drive current flowing through the solenoid is increased to reach a specific drive current and the valve opening degree when the drive current is decreased and controlled to a specific drive current.

FIG. 1 is a diagram showing a proportional solenoid valve system according to a first embodiment. FIG. 2 is a diagram showing a valve mechanism of a proportional solenoid valve. It is a figure showing the valve drive mechanism of a proportional solenoid valve. 4 is a flowchart showing a control process of a proportional solenoid valve. 11A and 11B are diagrams illustrating polarity inversion, level control, and generation of attraction force of a drive current by PWM control. It is a figure showing the proportional solenoid valve system concerning a 2nd embodiment. It is a figure which shows the proportional solenoid valve based on 3rd Embodiment. FIG. 3 is a diagram showing the operating characteristics of a proportional solenoid valve driven by a drive current without polarity reversal. FIG. 3 is a diagram showing the operating characteristics of a proportional solenoid valve driven by a drive current with polarity reversal.

[First embodiment]
FIG. 1 shows a proportional solenoid valve system 2 according to a first embodiment. The configuration shown in FIG. 1 is an example, and the present disclosure is not limited to such a configuration.
This proportional solenoid valve system 2 includes a proportional solenoid valve 4 and a control device 6 . The proportional solenoid valve 4 is installed, for example, in a fluid path 8 through which a fluid G such as fuel gas flows. The valve chamber 10 is formed with an inlet port 12-1 and an outlet port 12-2. Fluid G flowing into the fluid path 8 is introduced into the valve chamber 10 from the inlet port 12-1, passes through the valve mechanism 14 from the valve chamber 10, and flows into the fluid path 8 from the outlet port 12-2. The flow direction of the fluid G indicated by the arrow is only an example.

The valve mechanism 14 includes a valve seat 16 and a valve element 18. The valve seat 16 is fixed to the wall surface of the valve chamber 10, and the valve element 18 moves in a direction perpendicular to the valve seat surface of the valve seat 16.
A diaphragm 24 is attached by a support member 22 to a shaft portion 20 formed on the central axis of the valve element 18. The outer edge of the diaphragm 24 is supported between the inner walls of the valve chamber 10. Therefore, the valve element 18 is supported by the diaphragm 24 so as to be able to move up and down in the valve chamber 10, and when the pressure of the fluid G acts on the inside of the valve chamber 10, the diaphragm 24 bulges and pulls the valve element 18 down.

A movable magnetic pole 26 is provided relative to the valve body 18, and this movable magnetic pole 26 is in contact with the shaft portion 20 of the valve body 18. In other words, the movable magnetic pole 26 constitutes a plunger. This movable magnetic pole 26 is inserted into a proportional solenoid 28 and is movable in the central axial direction of the valve body 18. A yoke 32 is provided in the proportional solenoid 28 with a coil 30 sandwiched therebetween. The coil 30 is wound around a coil bobbin 34 and provided in the proportional solenoid 28. Therefore, the yoke 32 constitutes a fixed magnetic pole relative to the movable magnetic pole 26.
A support frame 36 is fixed to the yoke 32 side, and a space 38 is formed in the support frame 36 to allow the diaphragm 24 to bulge.
A support member 40 is fixed to the yoke 32, and the support member 40 has a spring support portion 42. A spring insertion portion 44 is formed in the movable magnetic pole 26, and a coil spring 46 is installed between the spring insertion portion 44 and the spring support portion 42. Therefore, the restoring force of the spring 46 acts on the movable magnetic pole 26.

The control device 6 includes, for example, a drive unit 48 and a control unit 50, and generates a drive current id, inverts the polarity, and controls the level. The drive unit 48 generates a drive current id under the control of the control unit 50, and passes this drive current id to the proportional solenoid 28. The control unit 50 includes, for example, a computer, and receives detection outputs from various sensors, such as a temperature sensor and a water volume sensor, as a control signal Sin, and performs information processing for controlling the proportional solenoid valve 4. This information processing includes the following:
(a) Control for generating driving current i
(b) Reversal of polarity of the drive current id due to a period faster than the movement of the valve disc 18
(c) Control of the valve opening degree by the current level of the drive current id.

<Valve mechanism 14>
2 shows an enlarged view of the valve mechanism 14 of the proportional solenoid valve 4. The valve seat 16 is fixed to the valve chamber 10 by a retaining frame 51, and the gap between the valve seat 16 and the inner wall surface of the valve chamber 10 is sealed by an O-ring 52.
The valve body 18 has a conical surface portion 54, and this conical surface portion 54 and a valve opening portion 56 of the valve seat 16 perform a valve function.
In the valve chamber 10, a circular recess 58, for example, is formed on the central axis of the valve disc 18, facing the valve disc 18. In the valve chamber 10, a protrusion 60 is formed on the large-diameter surface of the valve disc 18, facing the recess 58. When the valve disc 18 moves, the protrusion 60 enters the recess 58 on the valve chamber 10 side, allowing the valve disc 18 to move.

<Valve drive mechanism 62 and generation of suction force F>
FIG. 3 shows a valve drive mechanism 62 for the proportional solenoid valve 4. As shown in FIG. The valve drive mechanism 62 drives the valve body 18 in the vertical direction by excitation of the drive current id.
When the drive current id flows through the proportional solenoid 28, a magnetic field φ is generated in the proportional solenoid 28. As a result, the movable magnetic pole 26 and the yoke 32 (fixed magnetic pole) are magnetized, and mutually different magnetic poles N and S are generated in the movable magnetic pole 26 and the yoke 32. moves in the direction of the attractive force F. Regardless of the direction of the drive current id, different magnetic poles N and S are generated in the movable magnetic pole 26 and the yoke 32, so that an attractive force F is exerted by the magnetic pole NS.

<Polarity Reversal of Drive Current id>
When the polarity of the drive current id is reversed at regular intervals, the polarity of the magnetic poles N and S of the movable magnetic pole 26 and the yoke 32 is reversed, but an attractive force F acts between them in the same direction. As a result, a valve opening degree according to the current level of the drive current id can be obtained regardless of the polarity.
When the drive current id is reversed, the magnetization direction of the movable magnetic pole 26 and the yoke 32 is reversed, so that the residual magnetism is offset by the reversed current, and the influence of the residual magnetism can be eliminated.

<Control process of proportional solenoid valve 4>
A in FIG. 4 shows an example of a control process of the proportional solenoid valve 4. This control step includes generation of the drive current id (S101), polarity reversal of the drive current id (S102), current level control of the drive current id (S103), and the like.
Generation of drive current id (S101): The control device 6 generates a drive current id to be passed through the proportional solenoid 28.
Reversal of polarity of drive current id (S102): The control device 6 reverses the polarity of the drive current id at a cycle faster than the moving speed of the valve body 18. The movement of the valve body 18 depends on the fluctuation of the current level of the drive current id, and the polarity reversal of the drive current id is performed at a cycle faster than the movement speed of the valve body 18, for example, at a cycle that is 1/2 of the dither cycle Td.
Current level control of drive current id (S103): The control device 6 controls the current level of the drive current id, and controls the valve mechanism 14 to the valve opening degree according to the current level.

B in FIG. 4 shows an example of polarity inversion and level control of the drive current id in this control process. This control process includes inputting the control signal Sin (S201), calculating the duty ratio of the forward pulse (S202), calculating the duty ratio of the reverse pulse (S203), and generating the forward pulse (pulse based on the calculated duty ratio). The process includes control execution) (S204), generation of reverse direction pulses (execution of pulse control based on the calculated duty ratio) (S205), control of valve opening degree (S206), and the like.
Input of control signal Sin (S201): The control device 6 receives a control signal Sin for controlling the valve opening degree of the valve mechanism 14. The valve opening degree is controlled by the signal level of this control signal Sin.

Calculating the duty ratio of forward direction pulses (S202): The control device 6 calculates the duty ratio of forward direction pulses excluding the polarity control pulse Psw1 (polarity inversion section) which will be described later.
Calculation of duty ratio of reverse direction pulse (S203): The control device 6 calculates the duty ratio of reverse direction pulses except for a polarity control pulse Psw2 (polarity inversion section) which will be described later.

Generation of forward direction pulse (execution of pulse control using calculated duty ratio) (S204): The control device 6 generates a forward direction pulse for generating the forward direction drive current id to flow through the proportional solenoid 28. This forward pulse includes a polarity control pulse Psw1 as a polarity reversal portion at the beginning for reversing the current direction of the drive current id faster than the movement of the valve body 18. This polarity control pulse Psw1 has a larger pulse width than other forward direction pulses and is a high duty ratio pulse. The polarity inversion section in the forward pulse is used to switch the polarity of the reverse drive current id to the forward drive current id.
Generation of reverse direction pulse (execution of pulse control based on calculated duty ratio) (S205): The control device 6 generates a reverse direction pulse for generating the reverse direction drive current id to flow through the proportional solenoid 28. This reverse direction pulse includes a polarity control pulse Psw2 as a polarity reversal portion at the beginning for reversing the current direction of the drive current id faster than the movement of the valve body 18. This polarity control pulse Psw2 has a larger pulse width than other reverse direction pulses and is a high duty ratio pulse. The polarity reversal part in the reverse direction pulse is used to switch the polarity of the forward direction drive current id to the reverse direction drive current id.
Control of valve opening degree (S206): The control device 6 controls the current level of the drive current id according to the signal level of the control signal Sin, and controls the valve opening degree.

<Polarity reversal of drive current id, its level control and attraction force F>
A in FIG. 5 shows a forward PWM pulse, which is an example of a forward pulse. This forward pulse is generated with a period of 1/2 (=Td/2) of the dither period Td, and includes a polarity control pulse Psw1 as a polarity inversion part at the beginning. The polarity control pulse Psw1 has a constant pulse width in order to shorten the polarity inversion period during which the reverse drive current id is switched to the forward direction.
On the other hand, the duty ratio of the forward direction PWM pulses other than the polarity control pulse Psw1 is controlled by the control signal Sin. In FIG. 5A, the duty ratio is set to be constant for convenience of explanation, but the duty ratio is controlled to vary depending on the valve opening degree.

FIG. 5B shows a reverse PWM pulse, which is an example of a reverse pulse. This reverse pulse is generated for a period of 1/2 (=Td/2) of the dither period Td, and includes a polarity control pulse Psw2 as a polarity reversal part at the beginning. The polarity control pulse Psw2 has a constant pulse width in order to shorten the polarity reversal period in which the forward drive current id is switched to the reverse direction. In this embodiment, the polarity control pulses Psw1 and Psw2 have the same pulse width.
On the other hand, the duty ratio of the reverse PWM pulses excluding the polarity control pulse Psw2 is controlled by the control signal Sin. For convenience of explanation, the duty ratio is set to a constant value in B of Fig. 5, but the duty ratio is controlled to a different value depending on the valve opening degree.

5C shows a driving current id flowing in the forward or reverse direction. The driving current id is repeatedly switched from the reverse driving current id to the forward driving current id and then from the forward driving current id to the reverse driving current id by alternately generating a polarity control pulse Psw1 and a polarity control pulse Psw2 every half of the dither period Td.
The drive current id with this polarity reversal depends on the duty ratio of the forward PWM pulse or the reverse PWM pulse, and the current level is controlled.

D in FIG. 5 shows the attractive force F acting on the movable magnetic pole 26 and the yoke 32 (fixed magnetic pole). The proportional solenoid 28 is excited by a drive current id with polarity reversal and level control, magnetizing the movable magnetic pole 26 and the yoke 32. The magnetic poles are reversed to a different pair every half of the dither period Td, and the attractive force F generated between the movable magnetic pole 26 and the yoke 32 depends on the level of the drive current id.

Effects of the First Embodiment
According to the first embodiment, any one of the following effects can be obtained.
(1) The polarity of the drive current id is reversed at half the dither period Td (=Td/2) to reverse the magnetic pole between the movable magnetic pole 26 and the yoke 32 by the proportional solenoid 28, thereby canceling out residual magnetism. This polarity reversal is performed at a period faster than the opening and closing of the valve mechanism 14, so it does not affect the control of the valve opening.
(2) During the time interval between polarity reversals, the current level of the drive current id is controlled by the duty ratio of the forward PWM pulse or the reverse PWM pulse. Therefore, the valve opening of the valve mechanism 14 can be controlled by the current level of the drive current id without being affected by the polarity reversal of the drive current id.

[Second embodiment]
FIG. 6 shows a proportional solenoid valve system 2 according to a second embodiment. In the configuration of FIG. 6, the same parts as in FIG. 1 are given the same reference numerals.
The drive section 48 includes a power supply 64, a drive bridge circuit 66, a forward drive circuit 68-1, and a reverse drive circuit 68-2. The power supply 64 constitutes a current source of the drive current id.
The drive bridge circuit 66 includes Pch-FETs (P-channel field effect transistors) 71 and 72 and Nch-FETs (N-channel field effect transistors) 73 and 74.

The forward drive circuit 68-1 receives a forward PWM pulse from the control unit 50 and causes a forward drive current id to flow from the drive bridge circuit 66 to the proportional solenoid 28. On the other hand, the reverse drive circuit 68-2 receives the reverse PWM pulse from the control unit 50 and causes the drive current id in the reverse direction to flow from the drive bridge circuit 66 to the proportional solenoid 28. That is, in the half period (=Td/2) of the dither period Td, the forward drive current id flows to the proportional solenoid 28 due to conduction of the Pch-FET 72 and the Nch-FET 73, and in the next half period (=Td/2) of the dither period Td. In 2), the drive current id in the opposite direction flows to the proportional solenoid 28 due to conduction of the Pch-FET 71 and the Nch-FET 74.

The control section 50 includes a control circuit 76, a pulse generation section 78, a PWM generation section 80, and a logic circuit 82. The control circuit 76 is composed of a microcomputer and includes a processor 84, a storage section 86, and an input/output section (I/O) 88. The processor 84 executes the control program stored in the storage unit 86 and performs control such as pulse width control according to the control signal Sin.
Such controls and control information include:
a) Control information for generating the drive current id b) Control information for reversing the polarity of the drive current id at a faster cycle than the movement of the valve body 18 c) Control information for controlling the valve opening depending on the current level of the drive current id d) Calculation of duty ratio of forward direction pulses excluding polarity control pulses e) Calculation of duty ratios of reverse direction pulses excluding polarity control pulses f) Order including control pulses that switch the polarity of reverse drive current id to forward direction Generation of directional pulses (execution of calculated pulse control)
g) Generation of a reverse pulse including a control pulse that switches the polarity of the forward drive current id to the opposite direction (execution of the calculated pulse control)
is included.

The storage unit 86 is an example of a recording medium that stores the program of the present disclosure. This storage unit 86 uses storage elements such as ROM (Read-Only Memory), RAM (Random-Access Memory), and EEPROM (Electrically Erasable Programmable Read-Only Memory), and is used to generate and store various control information. .
The I/O 88 takes in the control signal Sin and generates control information.
The pulse generator 78 generates a clock pulse with a constant period, and generates a pulse with a constant period by dividing or doubling the frequency of this clock pulse.

The PWM generating unit 80 has a forward PWM pulse generating function and a reverse PWM pulse generating function, generates a forward PWM pulse or a reverse PWM pulse having a duty ratio according to the signal level of the control signal Sin, and outputs it to the logic circuit 82.
The logic circuit 82 receives a control pulse synchronized with a half period of the dither period Td from the pulse generating unit 78, and outputs a forward PWM pulse and a reverse PWM pulse synchronized with Td/2. The forward PWM pulse is provided to the forward drive circuit 68-1, and the reverse PWM pulse is provided to the reverse drive circuit 68-2.

<Effects of the second embodiment>
According to the second embodiment, one of the following effects can be obtained.
(1) The polarity of the drive current id is reversed at half the dither period Td (=Td/2) to reverse the magnetic pole between the movable magnetic pole 26 and the yoke 32 caused by the proportional solenoid 28, thereby canceling out residual magnetism. hysteresis characteristics can be improved.
(2) During the time interval of polarity reversal, the current level of the drive current id can be controlled by the duty ratio of the forward PWM pulse or the reverse PWM pulse, and the drive current id can be controlled without being affected by the polarity reversal of the drive current id. Controllability of the valve opening degree of the valve mechanism 14 can be improved by changing the current level.

[Third embodiment]
FIG. 7 shows a proportional solenoid valve 404 according to a third embodiment. In the configuration of FIG. 7, the same parts as in FIG. 1 are given the same reference numerals.
In this third embodiment, a proportional solenoid valve main body 400 is a valve function part of the proportional solenoid valve 4 of the first embodiment.
A proportional solenoid valve body 400, a drive section 48, and a control section 50 are installed in the housing 402. Therefore, in this embodiment, a proportional solenoid valve 404 that integrally includes a control function is configured.

〔Experimental result〕
FIG. 8, with time on the horizontal axis and valve opening on the vertical axis, shows the operating characteristics of the proportional solenoid valves 4, 404 driven by a drive current id without polarity switching.
When the proportional solenoid 28 is excited by a drive current id that does not involve polarity reversal, the effect of residual magnetism cannot be eliminated because the drive current id is unidirectional. In other words, the magnetization is emphasized by a drive current id that is in the same direction as the residual magnetism, whereas the magnetization by the drive current id is impaired by a drive current id that is in the opposite direction to the residual magnetism, due to the cancellation of the residual magnetism. As a result, the effect of hysteresis h between the control signal Sin and the valve opening becomes significant.

Similarly, FIG. 9 shows the operating characteristics of the proportional solenoid valve 4, 404 driven by the drive current id with polarity switching, with time on the horizontal axis and valve opening degree on the vertical axis.
When the proportional solenoid 28 is excited with a drive current id with polarity reversal, residual magnetism is canceled out by the drive current id due to the polarity reversal, and a relationship between the drive current id and the valve opening degree that is free from the influence of residual magnetism is obtained. As a result, the influence of hysteresis h between the control signal Sin and the valve opening degree is improved to the extent that it can be ignored.

Other Embodiments
(1) In the above embodiment, PWM control is used as an example. However, the proportional solenoid valve may be controlled by a method other than PWM control.
(2) The inversion period of the drive current id is set to half the dither period Td, but it need only be faster than the moving speed of the valve disc 18 and is not limited to the period in the embodiment.
(3) In the above embodiment, the polarity control pulse is illustrated as an example in the polarity reversal portion included in the forward pulse or reverse pulse, but this polarity control pulse may be a pulse generated by PWM control or a polarity reversal pulse generated separately from PWM control. This polarity reversal pulse may have a period including an optimal polarity reversal timing for reversing the polarity of the drive current id, and may have a pulse width set to an optimal time width.

As described above, the most preferred embodiment of the configuration of the present invention has been described. The present invention is not limited to the above description, and various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the description for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

According to the present invention, residual magnetism can be canceled by reversing the magnetic pole relationship between the movable magnetic pole and the fixed magnetic pole (yoke) using a drive current, and the valve mechanism can be driven by magnetic force that is not affected by residual magnetism, thereby improving hysteresis characteristics. .

2 Proportional solenoid valve system 4, 404 Proportional solenoid valve 6 Control device G Fluid 8 Fluid path 10 Valve chamber 12-1 Inlet port 12-2 Outlet port 14 Valve mechanism 16 Valve seat 18 Valve body 20 Shaft portion 22 Support member 24 Diaphragm 26 Movable magnetic pole 28 Proportional solenoid 30 Coil 32 Yoke 34 Coil bobbin 36 Support frame 38 Space portion 40 Support member 42 Spring support portion 44 Spring insertion portion 46 Spring 48 Drive portion 50 Control portion 51 Retaining frame 52 O-ring 54 Conical surface portion 56 Valve opening portion 58 Convex portion 60 Convex portion 62 Valve drive mechanism 64 Power source 66 Drive bridge circuit 68-1 Forward drive circuit 68-2 Reverse drive circuit 71, 72 Pch-FET
73, 74 Nch-FET
76 Control circuit 78 Pulse generating unit 80 PWM generating unit 82 Logic circuit 84 Processor 86 Storage unit 88 Input/output unit (I/O)
400 Proportional solenoid valve body 402 Housing

Claims (12)

A method for controlling a proportional solenoid valve in which a valve opening is controlled by energizing a proportional solenoid, comprising the steps of:
generating a drive current to energize the proportional solenoid;
generating a forward pulse including a polarity reversal portion for reversing the polarity of the reverse drive current to a forward current;
generating a reverse pulse including a polarity reversal portion for reversing the polarity of the forward drive current to a reverse direction;
using the forward pulse and the reverse pulse to invert the polarity of the drive current at a period faster than the movement of the valve body;
controlling a valve opening degree according to a current level of the drive current;
1. A method for controlling a proportional solenoid valve, comprising: controlling the duty ratio of the forward pulse excluding the polarity reversal portion;
controlling the duty ratio of the reverse direction pulse excluding the polarity reversal portion;
The method for controlling a proportional solenoid valve according to claim 1, comprising: a proportional solenoid valve whose valve opening is controlled by energizing a proportional solenoid;
a drive unit that generates a drive current for exciting the proportional solenoid and causes the drive current to flow through the proportional solenoid;
a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the reverse driving current to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the forward driving current to a reverse direction;
a control unit that uses the forward pulse and the reverse pulse to invert the polarity of the drive current at a period faster than the movement of the valve body and controls the valve opening degree according to the current level of the drive current;
A proportional solenoid valve system comprising: a pulse width control section for controlling a duty ratio of the forward pulse excluding a polarity reversal section, or a duty ratio of the reverse pulse excluding a polarity reversal section;
4. The proportional solenoid valve system of claim 3, further comprising: a drive unit that generates a drive current for exciting a proportional solenoid that controls a valve opening degree by excitation, and passes the drive current through the proportional solenoid;
a control unit including a logic circuit that generates a forward pulse including a polarity reversal unit that reverses the polarity of the reverse drive current to a forward direction and generates a reverse pulse including a polarity reversal unit that reverses the polarity of the forward drive current to a reverse direction, the control unit using the forward pulse and the reverse pulse to reverse the polarity of the drive current at a period faster than the movement of the valve body and control the valve opening degree according to the current level of the drive current;
A control device for a proportional solenoid valve comprising: The control section further includes a pulse width control section that controls a duty ratio of the forward direction pulse excluding the polarity inversion section or a duty ratio of the reverse direction pulse excluding the polarity inversion section;
6. The proportional solenoid valve control device according to claim 5, further comprising: A program realized by a computer,
A function to generate control information for generating a drive current to excite a proportional solenoid;
a function of generating a forward pulse including a polarity inversion section that inverts the polarity of the drive current in the reverse direction to the forward direction;
a function of generating a reverse direction pulse including a polarity reversal section that reverses the polarity of the forward driving current;
A function of generating control information that uses the forward direction pulse and the reverse direction pulse to reverse the polarity of the drive current at a cycle faster than the movement of the valve body;
a function of generating control information for controlling the valve opening degree based on the current level of the drive current;
A program for realizing the above using the computer. Further , a function of controlling the duty ratio of the forward direction pulse excluding the polarity inversion part;
a function of controlling the duty ratio of the reverse direction pulse excluding the polarity inversion part;
The program according to claim 7, which is realized by the computer. A recording medium storing the program according to claim 7 or claim 8. a valve mechanism controlled by energizing a proportional solenoid;
A drive unit that supplies a drive current to the proportional solenoid;
a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the reverse driving current to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the forward driving current to a reverse direction;
a control unit that uses the forward pulse and the reverse pulse to invert the polarity of the drive current at a period faster than the movement of the valve body to cancel out residual magnetism and adjusts the valve opening degree according to the current level of the drive current;
A proportional solenoid valve comprising: A valve mechanism;
a proportional solenoid for controlling the valve mechanism by excitation;
a drive unit that generates a drive current for exciting the proportional solenoid and causes the drive current to flow through the proportional solenoid;
a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the reverse driving current to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the forward driving current to a reverse direction;
a control unit that uses the forward pulse and the reverse pulse to invert the polarity of the drive current at a period faster than the movement of the valve body and controls the valve opening degree according to the current level of the drive current;
A proportional solenoid valve comprising: The control section further includes a pulse width control section that controls a duty ratio of the forward direction pulse excluding the polarity inversion section or a duty ratio of the reverse direction pulse excluding the polarity inversion section;
The proportional solenoid valve according to claim 10 or claim 11, characterized in that it comprises:

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