Method, system, device, program, recording medium for controlling a proportional solenoid valve, and proportional solenoid valve

Abstract

To achieve desired valve opening according to a level of driving current while avoiding an impact of residual magnetism by causing a proportional solenoid to generate an alternating magnetic field.SOLUTION: A method for controlling a proportional solenoid valve includes the steps of: generating driving current; exciting a proportional solenoid 28 according to a current level of the driving current, and magnetizing a yoke 32 and a movable magnetic pole 26 to mutually different magnetic poles by the excitation of the proportional solenoid irrespective of a flow direction of the driving current; moving a valve body 18 by the attractive force of the magnetic pole generated in the movable magnetic pole and the yoke; and reversing the polarity of the driving current at a cycle faster than the movement of the valve body to generate an alternating magnetic field, and offsetting at least the residual magnetism of the movable magnetic pole.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a proportional solenoid valve used, for example, in a fuel gas control valve and the like, and a control technique for the same. [Background technology]

[0002] Valves are used to control fluids such as fuel gas, and a known example of this valve is a proportional solenoid valve that controls the valve opening by exciting a solenoid. The opening degree of the proportional solenoid valve is controlled, for example, by a PWM (pulse width modulation) method. Regarding the PWM control of this proportional solenoid valve, a control that increases or decreases the period of dither vibration regardless of the magnitude of the current flowing in a suspension control device is known (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-258625 Summary of the Invention [Problem to be solved by the invention]

[0004] 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.

[0005] 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 changing 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 generate an alternating magnetic field in a proportional solenoid to avoid the effects of residual magnetism, while obtaining a desired valve opening degree by adjusting the level of the drive current. [Means for solving the problem]

[0006] In order to achieve the above object, according to one aspect of the control method for a proportional solenoid valve of the present disclosure, there is provided a method for controlling a proportional solenoid valve, comprising the steps of: generating a drive current; exciting a proportional solenoid in accordance with a current level of the drive current, and magnetizing a yoke and a movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of a flow direction of the drive current; Regardless of the direction of the drive current The valve body is moved by the magnetic attraction force generated between the movable magnetic pole and the yoke. In a certain direction A step of moving the The polarity of the drive current is inverted. At a cycle faster than the movement of the valve disc Go and generating an alternating magnetic field to cancel out at least the residual magnetism of the movable magnetic pole. This control method for a proportional solenoid valve may include the steps of generating a forward pulse including a polarity reversal portion that reverses the polarity of the reverse drive current to a forward direction, generating a reverse pulse including a polarity reversal portion that reverses the polarity of the forward drive current to the reverse direction, controlling a duty ratio of the forward pulse excluding the polarity reversal portion, and controlling the duty ratio of the reverse pulse excluding the polarity reversal portion.

[0007] In order to achieve the above object, according to one aspect of the proportional solenoid valve system of the present disclosure, there is provided a proportional solenoid valve in which a valve element is controlled by excitation of a proportional solenoid, a drive unit that generates a drive current to be passed through the proportional solenoid, excites the proportional solenoid in accordance with a current level of this drive current, and magnetizes a yoke and a movable magnetic pole to mutually different magnetic poles by excitation of the proportional solenoid regardless of the flow direction of the drive current, Regardless of the direction of the drive current The magnetic pole is attracted to the movable magnetic pole by the magnetic pole attraction force generated between the movable magnetic pole and the yoke. In a certain direction and a control unit that generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the moving valve body, thereby offsetting at least the residual magnetism of the movable magnetic pole. This proportional solenoid valve system further includes a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the reverse drive current to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the forward drive current to the reverse direction, and a pulse width control section that controls the duty ratio of the forward pulse excluding the polarity reversal section or the duty ratio of the reverse pulse excluding the polarity reversal section.

[0008] In order to achieve the above object, according to one aspect of a control device for a proportional solenoid valve of the present disclosure, there is provided a control device for a proportional solenoid valve in which a valve element is controlled by excitation of a proportional solenoid, the control device generating a drive current to be passed through the proportional solenoid, exciting the proportional solenoid in accordance with a current level of the drive current, and controlling the proportional solenoid regardless of a flow direction of the drive current. By excitation a drive unit that magnetizes the yoke and the movable magnetic pole to different magnetic poles; Regardless of the direction of the drive currentThe magnetic pole is attracted to the movable magnetic pole by the magnetic pole attraction force generated between the movable magnetic pole and the yoke. In a certain direction and a control unit that generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the moving valve body, thereby offsetting at least the residual magnetism of the movable magnetic pole. In this proportional solenoid valve control device, the control unit may further include a logic circuit that generates a forward pulse including a polarity reversing unit that reverses the polarity of the reverse drive current to a forward direction, and generates a reverse pulse including a polarity reversing unit that reverses the polarity of the forward drive current to the reverse direction, and a pulse width control unit that controls the duty ratio of the forward pulse excluding the polarity reversing unit or the duty ratio of the reverse pulse excluding the polarity reversing unit.

[0009] In order to achieve the above object, according to one aspect of a program of the present disclosure, there is provided a program implemented by a computer, the program having a function of generating control information for generating a drive current for exciting a proportional solenoid, a function of exciting the proportional solenoid in accordance with a current level of the drive current, and a function of magnetizing a yoke and a movable magnetic pole to mutually different magnetic poles by exciting the proportional solenoid regardless of a flow direction of the drive current, Regardless of the direction of the drive current The magnetic pole is attracted to the movable magnetic pole by the magnetic pole attraction force generated between the movable magnetic pole and the yoke. In a certain direction The computer realizes a function of generating an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the moving valve body, thereby canceling out at least the residual magnetism of the movable magnetic pole. In this program, the computer may further realize a function of generating a forward pulse including a polarity reversal section that reverses the polarity of the reverse drive current to a forward direction, a function of generating a reverse pulse including a polarity reversal section that reverses the polarity of the forward drive current to the reverse direction, a function of controlling a duty ratio of the forward pulse excluding the polarity reversal section, and a function of controlling the duty ratio of the reverse pulse excluding the polarity reversal section. In order to achieve the above object, according to one aspect of the present disclosure, a recording medium storing the program is Computer readable It is a recording medium.

[0010] In order to achieve the above object, according to one aspect of the proportional solenoid valve of the present disclosure, there is provided a valve mechanism in which a valve body is controlled by excitation of a proportional solenoid; A drive current is generated to flow through the proportional solenoid. a driving unit that excites the proportional solenoid in response to a current level of a driving current and magnetizes the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the driving current; Regardless of the direction of the drive current The magnetic pole is attracted to the movable magnetic pole by the magnetic pole attraction force generated between the movable magnetic pole and the yoke. In a certain direction At a cycle faster than the movement of the moving valve disc The polarity of the drive current is Flip it An alternating magnetic field is generated, and at least one of the movable magnetic poles and a control unit that cancels out residual magnetism.

[0011] In order to achieve the above object, according to one aspect of the proportional solenoid valve of the present disclosure, there is provided a valve mechanism, a proportional solenoid that controls the valve mechanism by excitation, and a drive unit that excites the proportional solenoid in accordance with a current level of a drive current and magnetizes a yoke and a movable magnetic pole to different magnetic poles by excitation of the proportional solenoid regardless of the flow direction of the drive current. Regardless of the direction of the drive current The magnetic pole is attracted to the movable magnetic pole by the magnetic pole attraction force generated between the movable magnetic pole and the yoke. In a certain direction The valve includes a control unit that reverses the polarity of the drive current at a cycle faster than the movement of the moving valve element, and controls the valve opening degree according to the current level of the drive current. In the proportional solenoid valve, the control unit may further include a logic circuit that generates a forward pulse including a polarity reversing unit that reverses the polarity of the reverse drive current to a forward direction, and generates a reverse pulse including a polarity reversing unit that reverses the polarity of the forward drive current to the reverse direction, and a pulse width control unit that controls a duty ratio of the forward pulse excluding the polarity reversing unit or a duty ratio of the reverse pulse excluding the polarity reversing unit. Effect of the Invention

[0012] 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 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. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a proportional solenoid valve system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a valve mechanism of a proportional solenoid valve. [Diagram 3] FIG. 2 is a diagram showing a valve drive mechanism of a proportional solenoid valve. [Figure 4] 4 is a flowchart showing a control process of a proportional solenoid valve. [Diagram 5] 11A and 11B are diagrams illustrating polarity inversion of a drive current, level control, and generation of an attractive force by PWM control. [Figure 6] FIG. 13 is a diagram showing a proportional solenoid valve system according to a second embodiment. [Figure 7] FIG. 13 is a diagram showing a proportional solenoid valve according to a third embodiment. [Figure 8] FIG. 13 is a diagram showing the operating characteristics of a proportional solenoid valve driven by a drive current without polarity reversal. [Figure 9] FIG. 13 is a diagram showing the operating characteristics of a proportional solenoid valve driven by a drive current with polarity reversal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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 in a fluid path 8 through which a fluid G, such as fuel gas, flows. An inlet port 12-1 and an outlet port 12-2 are formed in a valve chest 10. The fluid G flowing in the fluid path 8 is introduced into the valve chest 10 from the inlet port 12-1, passes from the valve chest 10 through a valve mechanism 14, and flows into the fluid path 8 from the outlet port 12-2. The flow direction of the fluid G shown by the arrow is merely one example.

[0015] 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.

[0016] 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 that allows the diaphragm 24 to bulge is formed in the support frame 36 . 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.

[0017] 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: (a) Control for generating the drive current id (b) Polarity reversal of the drive current id due to a period faster than the movement of the valve disc 18 (c) Control of valve opening by the current level of the drive current id etc.

[0018] <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.

[0019] <Valve Drive Mechanism 62 and Generation of Suction Force F> 3 shows the valve drive mechanism 62 of the proportional solenoid valve 4. The valve drive mechanism 62 drives the valve element 18 in the vertical direction when excited with a drive current id. When a drive current id flows through the proportional solenoid 28, a magnetic field φ is generated in the proportional solenoid 28. This magnetizes the movable magnetic pole 26 and the yoke 32 (fixed magnetic pole), and different magnetic poles N and S are generated in the movable magnetic pole 26 and the yoke 32, and the movable magnetic pole 26 receives an attractive force F due to this magnetic pole NS and 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 due to the magnetic pole NS acts.

[0020] <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 yoke 32 is reversed, but an attractive force F acts between them in the same direction. As a result, the 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.

[0021] <Control process of proportional solenoid valve 4> 4A shows an example of a control process for the proportional solenoid valve 4. This control process includes generating a drive current id (S101), inverting the polarity of the drive current id (S102), and controlling the current level of the drive current id (S103). Generation of driving current id (S101): The control device 6 generates a driving current id to be flowed through the proportional solenoid . Reversing polarity of drive current id (S102): The control device 6 reverses the polarity of the drive current id at a period faster than the movement speed of the valve disc 18. The movement of the valve disc 18 depends on fluctuations in the current level of the drive current id, and the polarity of the drive current id is reversed at a period faster than the movement speed of the valve disc 18, for example, at a period that is 1 / 2 the dither period Td. Current level control of driving current id (S103): The control device 6 controls the current level of the driving current id, and controls the valve mechanism 14 to a valve opening degree according to the current level.

[0022] 4B shows an example of polarity inversion and level control of the drive current id in this control process. This control process includes input of a control signal Sin (S201), calculation of a duty ratio of a forward pulse (S202), calculation of a duty ratio of a reverse pulse (S203), generation of a forward pulse (execution of pulse control according to the calculated duty ratio) (S204), generation of a reverse pulse (execution of pulse control according to the calculated duty ratio) (S205), control of the valve opening (S206), etc. 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.

[0023] Calculation of duty ratio of forward pulse (S202): The controller 6 calculates the duty ratio of the forward pulse excluding the polarity control pulse Psw1 (polarity reversal portion) described later. Calculation of Duty Ratio of Reverse Pulse (S203): The controller 6 calculates the duty ratio of the reverse pulse excluding the polarity control pulse Psw2 (polarity reversal portion) described later.

[0024] Generation of forward pulse (execution of pulse control with calculated duty ratio) (S204): The control device 6 generates a forward pulse for generating a forward drive current id to be flowed through the proportional solenoid 28. This forward pulse includes a polarity control pulse Psw1 at the beginning as a polarity reversal section 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 the other forward pulses, and is a high duty ratio pulse. The polarity reversal 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 pulse (execution of pulse control with calculated duty ratio) (S205): The control device 6 generates a reverse pulse for generating a reverse drive current id to be flowed through the proportional solenoid 28. This reverse pulse includes a polarity control pulse Psw2 at the beginning as a polarity reversal section 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 the other reverse pulses, and is a high duty ratio pulse. The polarity reversal section in the reverse pulse is used to switch the polarity of the forward drive current id to the reverse drive current id. Control of valve opening degree (S206): The control device 6 controls the current level of the drive current id in accordance with the signal level of the control signal Sin, thereby controlling the valve opening degree.

[0025] <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 for a period of 1 / 2 the dither period Td (=Td / 2), and includes a polarity control pulse Psw1 as a polarity reversal part at the beginning. The polarity control pulse Psw1 has a constant pulse width to shorten the polarity reversal period during which the reverse drive current id is switched to the forward direction. On the other hand, the duty ratio of the forward PWM pulses excluding the polarity control pulse Psw1 is controlled by the control signal Sin. For convenience of explanation, the duty ratio is set to a constant value in A of Fig. 5, but the duty ratio is controlled to a different value depending on the valve opening degree.

[0026] 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 the dither period Td (=Td / 2), 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 to shorten the polarity reversal period during 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.

[0027] 5C shows the drive current id flowing in the forward or reverse direction. The drive current id is repeatedly switched from the reverse drive current id to the forward drive current id and then from the forward drive current id to the reverse drive 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 accompanying this polarity reversal depends on the duty ratio of the forward PWM pulse or the reverse PWM pulse, and the current level is controlled.

[0028] 5D 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 driving current id with polarity reversal and level control, magnetizing the movable magnetic pole 26 and the yoke 32. The magnetic pole pair is reversed 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 driving current id.

[0029] <Advantages 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 in a cycle faster than the opening and closing of the valve mechanism 14, so it does not affect the control of the valve opening degree. (2) During the time interval of polarity reversal, the current level of the drive current id is controlled by the duty ratio of the forward PWM pulse or 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.

[0030] 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 those in Fig. 1 are given the same reference numerals. The driving section 48 includes a power supply 64, a driving bridge circuit 66, a forward driving circuit 68-1, and a reverse driving circuit 68-2. The power supply 64 constitutes a current source of a driving 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.

[0031] 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 a reverse PWM pulse from the control unit 50 and causes a reverse drive current id to flow from the drive bridge circuit 66 to the proportional solenoid 28. In other words, in a half cycle (=Td / 2) of the dither cycle Td, the forward drive current id flows to the proportional solenoid 28 due to the conduction of the Pch-FET 72 and the Nch-FET 73, and in the next half cycle (=Td / 2) of the dither cycle Td, the reverse drive current id flows to the proportional solenoid 28 due to the conduction of the Pch-FET 71 and the Nch-FET 74.

[0032] The control unit 50 includes a control circuit 76, a pulse generating unit 78, a PWM generating unit 80, and a logic circuit 82. The control circuit 76 is configured with a microcomputer, and includes a processor 84, a storage unit 86, and an input / output unit (I / O) 88. The processor 84 executes a control program stored in the storage unit 86, and performs control such as pulse width control in response to a control signal Sin. Such control and control information includes: a) Control information for generating the drive current id b) Control information for reversing the polarity of the drive current id at a period faster than the movement of the valve body 18 c) Control information for controlling the valve opening according to the current level of the drive current id d) Calculation of the duty ratio of the forward pulse excluding the polarity control pulse e) Calculation of the duty ratio of the reverse pulse excluding the polarity control pulse f) Generation of forward pulses including a control pulse for switching the polarity of the reverse drive current id to the forward direction (execution of the calculated pulse control) g) Generation of reverse pulses including a control pulse for switching the polarity of the forward drive current id to the reverse direction (execution of the calculated pulse control) Includes:

[0033] The storage unit 86 is an example of a recording medium for storing the program of the present disclosure. The storage unit 86 uses memory elements such as a read-only memory (ROM), a random-access memory (RAM), and an electrically erasable programmable read-only memory (EEPROM), and is used to generate and store various types of control information. The I / O 88 receives the control signal Sin and generates control information. The pulse generating section 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.

[0034] 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.

[0035] <Advantages of the second embodiment> According to the second 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 and improving the hysteresis characteristics. (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 reverse PWM pulse. This improves the controllability of the valve opening of the valve mechanism 14 by the current level of the drive current id without being affected by the polarity reversal of the drive current id.

[0036] 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 those in Fig. 1 are given the same reference numerals. In this third embodiment, a proportional solenoid valve body 400 is the valve function portion of the proportional solenoid valve 4 in the first embodiment. A proportional solenoid valve body 400, a drive unit 48, and a control unit 50 are installed in a housing 402. Therefore, in this embodiment, a proportional solenoid valve 404 having an integrated control function is configured.

[0037] [Experimental Results] FIG. 8, with time on the horizontal axis and valve opening on the vertical axis, shows the operating characteristics of the proportional solenoid valve 4, 404 driven by a drive current id without polarity switching. When the proportional solenoid 28 is excited with 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 with a drive current id that is in the same direction as the residual magnetism, whereas the magnetization caused by the drive current id is impaired with a drive current id that is in the opposite direction to the residual magnetism, as the residual magnetism is offset. As a result, the effect of hysteresis h between the control signal Sin and the valve opening becomes noticeable.

[0038] FIG. 9 similarly shows the operating characteristics of the proportional solenoid valve 4, 404 driven by a drive current id with polarity switching, with the horizontal axis representing time and the vertical axis representing the valve opening. When the proportional solenoid 28 is excited by a drive current id accompanied by polarity reversal, the residual magnetism is offset 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 the residual magnetism is obtained. As a result, the influence of the hysteresis h between the control signal Sin and the valve opening degree is improved to a negligible level.

[0039] Other Embodiments (1) In the above embodiment, PWM control is used as an example. However, the proportional solenoid valve may be controlled by a control 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 element 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.

[0040] 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. [Industrial Applicability]

[0041] According to the present invention, the magnetic pole relationship between the movable magnetic pole and the fixed magnetic pole (yoke) can be reversed by the drive current to cancel out residual magnetism, and the valve mechanism can be driven by a magnetic force that is not affected by residual magnetism, thereby improving hysteresis characteristics. [Explanation of symbols]

[0042] 2 Proportional Solenoid Valve System 4, 404 Proportional Solenoid Valve 6. Control device G fluid 8 Fluid path 10 Valve chamber 12-1 Ingress port 12-2 Outgoing port 14 Valve mechanism 16 Valve seat 18 Valve body 20 Shaft 22 Support member 24 Diaphragm 26 Moving magnetic pole 28 Proportional Solenoid 30 Coil 32 York 34 Coil bobbin 36 Support frame 38 Space section 40 Support member 42 Spring support 44 Spring insertion part 46 Spring 48 Drive unit 50 Control section 51 Retaining frame 52 O-ring 54 Conical surface section 56 Valve Orifice 58 Recess 60 Convex 62 Valve drive mechanism 64 Power supply 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 Generator 80 PWM generation section 82 Logic Circuits 84 processors 86 Memory section 88 Input / output section (I / O) 400 Proportional Solenoid Valve Body 402 Case

Claims

1. generating a drive current; a step of magnetizing a proportional solenoid in response to a current level of the driving current, and magnetizing a yoke and a movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of a flow direction of the driving current; a step of moving a valve body in a fixed direction by an attractive force of the magnetic poles generated between the movable magnetic pole and the yoke regardless of a flow direction of the drive current; a step of generating an alternating magnetic field by inverting the polarity of the drive current at a period faster than the movement of the valve body, thereby canceling out at least the residual magnetism of the movable magnetic pole; 1. A method for controlling a proportional solenoid valve, comprising:

2. generating a forward pulse including a polarity reversal portion that reverses the polarity of the driving current in a reverse direction to a forward direction; generating a reverse pulse including a polarity reversal portion that reverses the polarity of the forward driving current to a reverse direction; controlling a duty ratio of the forward pulse excluding a polarity reversal portion; controlling a duty ratio of the reverse pulse excluding the polarity reversal portion; 2. The method of claim 1, further comprising:

3. a proportional solenoid valve in which a valve element is controlled by excitation of a proportional solenoid; a drive unit that generates a drive current to be passed through the proportional solenoid, excites the proportional solenoid in accordance with a current level of the drive current, and magnetizes the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the drive current; a control unit that generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the valve body, which moves in a fixed direction by the attractive force of the magnetic pole generated between the movable magnetic pole and the yoke regardless of the flow direction of the drive current, thereby canceling out at least the residual magnetism of the movable magnetic pole; A proportional solenoid valve system comprising:

4. a logic circuit that generates a forward pulse including a polarity reversal section that reverses the polarity of the driving current in the reverse direction to a forward direction, and generates a reverse pulse including a polarity reversal section that reverses the polarity of the driving current in the forward direction to a reverse direction; a pulse width control section that controls 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:

5. A control device for a proportional solenoid valve in which a valve element is controlled by energizing a proportional solenoid, a drive unit that generates a drive current to be passed through the proportional solenoid, excites the proportional solenoid in accordance with a current level of the drive current, and magnetizes the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the drive current; a control unit that generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the valve body, which moves in a fixed direction by the attractive force of the magnetic pole generated between the movable magnetic pole and the yoke regardless of the flow direction of the drive current, thereby canceling out at least the residual magnetism of the movable magnetic pole; A control device for a proportional solenoid valve comprising:

6. The control unit further includes a logic circuit that generates a forward pulse including a polarity reversal unit that reverses the polarity of the reverse driving current to a forward direction, and generates a reverse pulse including a polarity reversal unit that reverses the polarity of the forward driving current to a reverse direction; a pulse width control section that controls 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; 6. The control device for a proportional solenoid valve according to claim 5, further comprising:

7. A program implemented by a computer, A function of generating control information for generating a drive current for exciting the proportional solenoid; a function of exciting the proportional solenoid in response to a current level of the driving current, and magnetizing the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the driving current; A function of generating an alternating magnetic field by reversing the polarity of the driving current at a period faster than the movement of the valve body which moves in a fixed direction by the magnetic pole attraction force generated between the movable magnetic pole and the yoke regardless of the flow direction of the driving current, thereby canceling out at least the residual magnetism of the movable magnetic pole; A program for realizing the above by the computer.

8. Further, a function of generating a forward pulse including a polarity reversal portion that reverses the polarity of the driving current in the reverse direction to a forward direction; A function of generating a reverse direction pulse including a polarity reversal portion that reverses the polarity of the forward driving current to a reverse direction; A function of controlling the duty ratio of the forward pulse excluding the polarity reversal portion; A function of controlling the duty ratio of the reverse pulse excluding the polarity reversal portion; The program according to claim 7, which is implemented by the computer.

9. A computer-readable recording medium storing the program according to claim 7 or 8.

10. a valve mechanism in which a valve body is controlled by excitation of a proportional solenoid; a drive unit that generates a drive current to be passed through the proportional solenoid, excites the proportional solenoid in accordance with a current level of the drive current, and magnetizes the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the drive current; a control unit that generates an alternating magnetic field by reversing the polarity of the drive current at a period faster than the movement of the valve body, which moves in a fixed direction by the attractive force of the magnetic pole generated between the movable magnetic pole and the yoke regardless of the flow direction of the drive current, thereby canceling out at least the residual magnetism of the movable magnetic pole; A proportional solenoid valve comprising:

11. A valve mechanism; a proportional solenoid for controlling the valve mechanism by excitation; a driving unit that excites the proportional solenoid in response to a current level of a driving current and magnetizes the yoke and the movable magnetic pole to different magnetic poles by the excitation of the proportional solenoid regardless of the flow direction of the driving current; a control unit that reverses the polarity of the drive current at a period faster than the movement of the valve body, which moves in a fixed direction by the attractive force of the magnetic poles generated between the movable magnetic pole and the yoke regardless of the flow direction of the drive current, and controls the valve opening degree according to the current level of the drive current; A proportional solenoid valve comprising:

12. The control unit further includes a logic circuit that generates a forward pulse including a polarity reversal unit that reverses the polarity of the reverse driving current to a forward direction, and generates a reverse pulse including a polarity reversal unit that reverses the polarity of the forward driving current to a reverse direction; a pulse width control section that controls 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; 12. A proportional solenoid valve as claimed in claim 10 or 11, comprising:

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