JP2017078468A - Control method of electromagnetic valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a sound which is generated at the valve-opening of an electromagnetic valve.SOLUTION: In a control method of an electromagnetic valve which comprises a valve body (30), a valve seat (32) and a coil (40) and is opened by the application of a voltage to the coil, the control method comprises: a first process for deriving and updating a relationship between a current value and a response time while repeatedly acquiring data including the current value which flows at the application of the drive voltage, and the response time after start of the application of the drive voltage to the valve-opening; a second process for deriving a target current value when a magnitude of sound which is generated at the valve-opening reaches a tolerable value, or a target temperature of the coil, on the basis of the updated relationship when the valve-opening of the electromagnetic valve is required; and a third process for applying the drive voltage after continuing the application of a minute voltage until a current which flows at the application of the drive voltage reaches a target current value or lower when the target current value is derived at the second process, and applying the drive voltage after continuing the application of the minute voltage until a coil temperature reaches a target temperature when the target temperature is derived at the second process.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for controlling a solenoid valve.

  Conventionally, there has been a problem that abnormal noise is generated during the opening / closing control of the solenoid valve. For example, depending on the mode of the electromagnetic valve, abnormal noise generated when the valve body collides with the valve seat when closing from the open state may be a problem. As one of the methods for solving such problems, conventionally, when the solenoid valve is closed by energizing the solenoid for closing the valve, the position of the valve body that is closing is detected, and the valve body is the valve A method has been proposed in which energization of the valve-closing solenoid is temporarily stopped before colliding with the seat to reduce the speed when the valve body collides with the valve seat (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 11-81940 JP 2011-138790 A Japanese Patent Laying-Open No. 2015-169743

  Such a problem of abnormal noise can occur not only when the solenoid valve is closed but also when the valve is opened. Specifically, for example, when the valve is opened, abnormal noise generated when the valve body collides with a stopper fixed in the electromagnetic valve may be a problem. As a method of suppressing the sound pressure level of the sound generated at the time of opening the valve, the position of the valve body at the time of valve opening is detected and the valve body immediately before colliding with the stopper, as in the control at the time of closing the valve. In addition, a method of temporarily stopping energization of the coil of the solenoid valve is also conceivable. However, in an electromagnetic valve in which the amount of movement of the valve body is relatively small between the valve closing time and the valve opening time, it may be difficult to employ a method of stopping energization immediately before the valve body collides with the stopper.

  Also, in solenoid valves, since the valve seat is generally made of resin, the valve seat surface is gradually crushed (sagging occurs) by repeating the operation of the on-off valve, and the valve body and stopper when the valve is opened (Air gap), that is, the movement distance of the valve body when the valve is opened gradually increases. Therefore, simply detecting the position of the valve body that moves when the valve is opened cannot accurately know the distance between the valve body and the stopper, and the accuracy of noise reduction control may be reduced. For this reason, there has been a demand for a method for reducing the sound generated when the valve is opened even when the amount of movement (air gap) of the valve body between the valve closing time and the valve opening time varies.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to an aspect of the present invention, the valve body includes a valve body, a valve seat, and a coil, and the valve body seated on the valve seat is separated from the valve seat and opened by applying a voltage to the coil. A method for controlling an electromagnetic valve is provided. The electromagnetic valve control method includes: a current value that flows through the coil when a predetermined drive voltage is applied to the coil, and a period from when the application of the drive voltage is started until the valve body is opened. The response time is repeatedly acquired, the relationship between the current value and the response time is derived, and the derived relationship is continuously updated as the electromagnetic valve is repeatedly opened and closed. Step 1; When the opening of the solenoid valve is requested, the loudness generated when the solenoid valve is opened by applying the drive voltage to the coil based on the updated relationship. A second step of deriving a target current value that is a current value flowing through the coil or a target temperature that is a temperature of the coil when the value becomes an allowable value; and the target current value is derived in the second step Sometimes said A small voltage that is smaller than the drive voltage and does not open the solenoid valve is applied to the coil, and when the drive voltage is applied to the coil, the current flowing through the coil is less than or equal to the target current value. The application of the minute voltage is continued until it is determined to be, then the drive voltage is applied to the coil to open the solenoid valve, and when the target temperature is derived in the second step, Applying the minute voltage to the coil until the coil temperature reaches the target temperature, and then applying the driving voltage to the coil to open the solenoid valve; .

  According to the electromagnetic valve control method of this embodiment, even if the distance that the valve body moves when the valve body is closed is changed by continuing to use the electromagnetic valve, the loud sound generated when the electromagnetic valve is opened is large. The thickness can be suppressed to an allowable value or less.

  The present invention can be realized in various forms other than the control method of the solenoid valve. For example, a sound reduction method for a solenoid valve, a control program for the solenoid valve or a computer program that realizes the sound reduction method, a non-temporary recording medium that records the computer program, a solenoid valve, and a control unit that executes the control method are provided. It can be realized in the form of a device or the like.

It is a cross-sectional schematic diagram showing the structure of the solenoid valve at the time of valve closing. It is a cross-sectional schematic diagram showing the structure of the solenoid valve in the middle of valve opening. It is a cross-sectional schematic diagram showing the structure of the solenoid valve at the time of valve opening. It is explanatory drawing showing the relationship between the electric current at the time of valve opening, the position of a valve, and the speed of a valve. It is explanatory drawing which shows the relationship between the electric current which flows at the time of valve opening, and a sound pressure level. It is a flowchart showing a valve opening control processing routine. It is explanatory drawing which shows an example of the relationship between an electric current value and response time. It is explanatory drawing which shows the relationship between response time and an air gap. It is explanatory drawing which shows the relationship between the electric current which flows into a solenoid valve coil, and a sound pressure level. It is explanatory drawing which shows the relationship between the temperature of a solenoid valve coil, and resistance. It is explanatory drawing which shows the relationship between the resistance of a solenoid valve coil, and the flowing electric current. It is explanatory drawing which shows the relationship between the electric current value which flows into a solenoid valve coil, and a sound pressure level. It is a flowchart showing a valve opening control processing routine. It is explanatory drawing which shows the relationship between the temperature of a solenoid valve coil, and the flowing electric current.

A. First embodiment:
(A-1) Configuration of solenoid valve:
1-3 is a cross-sectional schematic diagram for demonstrating the opening-and-closing mechanism of the solenoid valve 10 as 1st Embodiment of this invention. The solenoid valve 10 is a pilot type solenoid valve including a main valve and a pilot valve. In the present embodiment, the solenoid valve 10 is provided in a hydrogen flow path for supplying hydrogen from a hydrogen tank to a fuel cell in a fuel cell vehicle equipped with a fuel cell system including a hydrogen tank and a fuel cell. .

  As shown in FIGS. 1 to 3, the electromagnetic valve 10 includes a housing 42, an electromagnetic valve coil 40, a pilot valve 20, a pilot valve seat 22, a pilot valve spring 24, a main valve 30, and a main valve seat 32. And a main valve spring 34 and a stopper 36. Further, the fuel cell system of the present embodiment including the electromagnetic valve 10 in the hydrogen flow path includes a control unit 50 for controlling each part of the fuel cell system including the electromagnetic valve 10.

  In the housing 42, a communication flow path 46 and a first through hole 44 are formed through the outer wall, and a communication space 41 is formed inside the housing 42. The communication space 41 communicates with a hydrogen tank (not shown) through the first through hole 44, and high-pressure hydrogen gas is supplied from the hydrogen tank. The communication channel 46 is connected to a channel for supplying hydrogen gas to an anode side channel of a fuel cell (not shown).

  The stopper 36 is disposed in the housing 42. The stopper 36 is fixed to the inner wall surface of the housing 42 and constitutes a part of the wall surface of the communication space 41 described above formed in the housing 42.

  The main valve 30 is made of a magnetic material and is housed in the communication space 41 in the housing 42. A hollow portion serving as a pilot space 43 is formed inside the main valve 30. The main valve 30 is provided with an orifice hole 38 and a second through hole 26 that penetrate the outer wall of the main valve 30. The orifice hole 38 allows communication between the pilot space 43 inside the main valve 30 and the communication flow path 46 provided in the housing 42. The second through hole 26 allows communication between a pilot space 43 inside the main valve 30 and a communication space 41 formed between the housing 42 and the main valve 30.

  A main valve seat 32 is provided on the inner wall surface of the housing 42 so as to surround the opening of the communication channel 46 described above. The main valve seat 32 can be formed of, for example, rubber or resin. The main valve 30 is closed by being seated on the main valve seat 32 and is opened by being separated from the main valve seat 32. In the following, in FIGS. 1 to 3, the direction indicated as the x direction is also referred to as a valve opening direction, and the direction indicated as the y direction is also referred to as a valve closing direction. The main valve 30 corresponds to a “valve element” in “means for solving the problem”, and the main valve seat 32 corresponds to a “valve seat” in “means for solving the problem”.

  In addition to the main valve 30, a main valve spring 34 is further disposed in the communication space 41 in the housing 42. The main valve spring 34 has one end fixed to the main valve 30 and the other end fixed to the stopper 36. More specifically, one end of the main valve spring 34 is fixed to a partition wall 39 that forms a part of the wall surface of the pilot space 43 in the main valve 30. The main valve spring 34 applies a force Fms in the y direction (the valve closing direction) to the main valve 30 (hereinafter also referred to as a main spring force Fms).

  The pilot valve 20 is made of a magnetic material and is accommodated in a pilot space 43 formed in the main valve 30. A pilot valve seat 22 is provided on the inner wall surface of the main valve 30 so as to surround the opening of the orifice hole 38. The pilot valve seat 22 can be formed of, for example, rubber or resin. The pilot valve 20 is closed by being seated on the pilot valve seat 22 and opened by being separated from the pilot valve seat 22. A pilot valve spring 24 is further arranged in the pilot space 43. One end of the pilot valve spring 24 is fixed to the pilot valve 20, and the other end is fixed to a partition wall 39 constituting a part of the wall surface of the pilot space 43 in the main valve 30. The pilot valve spring 24 applies a force Fps (hereinafter also referred to as a pilot spring force Fps) in the y direction (valve closing direction) to the pilot valve 20.

  When energized by a drive signal from the control unit 50 and excited, the solenoid valve coil 40 generates a suction force Fab that attracts the pilot valve 20 and the main valve 30 in the x direction (the valve opening direction). The attractive force Fab can be controlled by adjusting the energization amount to the electromagnetic valve coil 40. In the present embodiment, energization control in the solenoid valve 10 is performed based on the voltage value. The solenoid valve coil 40 corresponds to a “coil” in “Means for Solving the Problems”.

  The control unit 50 is configured as a logic circuit centered on a microcomputer, and includes a CPU, a ROM, a RAM, an input / output port for inputting and outputting various signals, and the like. The control unit 50 acquires detection signals from sensors provided in each part of the fuel cell system including the electromagnetic valve 10. Further, the control unit 50 outputs a drive signal to each part of the fuel cell system including the electromagnetic valve 10.

  FIG. 1 shows a state when the solenoid valve 10 is demagnetized (when the valve is closed), that is, a state where no current is passed through the solenoid valve coil 40 and no attractive force Fab is generated. At this time, in the pilot valve 20, a pilot spring force Fps is applied as a force for pressing the pilot valve 20 in the y direction (valve closing direction). Further, the pilot valve 20 has a y-direction (in the y direction) due to a pressure difference between the pilot space 43 to which high-pressure hydrogen gas is supplied and the orifice hole 38 (communication flow path 46) in which the supply of hydrogen gas is stopped. In the valve closing direction). In the main valve 30, a main spring force Fms is applied as a force that presses the main valve 30 in the y direction (valve closing direction). Further, the main valve 30 is moved in the y direction (valve closing direction) due to a pressure difference between the communication space 41 to which high-pressure hydrogen gas is supplied and the communication flow path 46 in which the supply of hydrogen gas is stopped. Pressed. As a result, both the pilot valve 20 and the main valve 30 are closed.

FIG. 2 shows a state at the start of excitation of the solenoid valve 10 (when a pilot valve to be described later is opened), that is, a state immediately after the current starts to flow through the solenoid valve coil 40. In the present embodiment, by the driving voltages V ₁ a predetermined performs energization of the solenoid valve coil 40. When the solenoid valve coil 40 is energized, the pilot valve 20 is attracted by the solenoid valve coil 40 with the suction force Fab. As a result, the pilot valve 20 is pulled up in the x direction against the force in the y direction described above, and the pilot valve 20 is opened. The drive voltage V ₁ is thus set so that the solenoid valve coil 40 generates a suction force that can move the pilot valve 20 in the x direction against the force in the y direction applied to the pilot valve 20 when the valve is closed. Has been. Incidentally, when the energization of the solenoid valve coil 40 is performed by the drive voltage V _1, but acts like attraction Fab also the main valve 30, the suction force Fab is added to the main valve 30 when the valve is closed above It is smaller than the force in the y direction. Therefore, immediately after the drive voltage V ₁ is applied to the electromagnetic valve coil 40, the main valve 30 maintains the closed body.

  When the pilot valve 20 is thus opened, the hydrogen gas supplied from the hydrogen tank flows to the communication flow path 46 through the first through hole 44, the communication space 41, the pilot space 43, and the orifice hole 38. As a result, the pressure in the communication channel 46 gradually increases.

  FIG. 3 shows a state where the main valve 30 of the solenoid valve 10 is opened by further energizing the solenoid valve coil 40 (excitation of the solenoid valve 10) from the state of FIG. In the solenoid valve 10, when the pilot valve 20 is opened by energization and the pressure of the communication flow path 46 (hereinafter also referred to as secondary pressure) rises, the communication space 41 to which hydrogen gas is supplied through the first through hole 44. The difference between the pressure (hereinafter also referred to as the primary pressure) and the secondary pressure is gradually reduced, and the force in the y direction applied to the main valve 30 is reduced. If the force in the x direction (suction force Fab) becomes equal to or greater than the force in the y direction due to the decrease in the force in the y direction in this way, and the force in the x direction exceeds the extent that the main valve 30 can be lifted, FIG. Thus, the main valve 30 is pushed up in the x direction. Thereby, the main valve 30 is opened, and the hydrogen gas in the hydrogen tank flows from the communication space 41 to the communication flow path 46 without passing through the pilot space 43.

  When the main valve 30 moves in the x direction and opens, the main valve 30 collides with the stopper 36 and generates a sound.

  When the main valve 30 is opened as shown in FIG. 3, the force in the y direction due to the difference between the primary pressure and the secondary pressure disappears as described above. As described above, in a state where there is no difference between the primary pressure and the secondary pressure, the open state of the main valve 30 can be maintained even if the energization amount in the solenoid valve coil 40 is made smaller than that at the time of opening the valve. Therefore, after the main valve 30 is opened, the control unit 50 of the present embodiment performs control to reduce the voltage so that the energization amount to the electromagnetic valve coil 40 becomes smaller.

  Note that when the energization to the solenoid valve coil 40 is stopped in a state where the main valve 30 is opened, the suction force Fab in the x direction disappears. Thereby, only the force in the y direction by the pilot valve spring 24 and the main valve spring 34 is applied, the main valve 30 is seated on the main valve seat 32, and the pilot valve 20 is seated on the pilot valve seat 22. The solenoid valve 10 is closed.

(A-2) About the operation sound of the solenoid valve:
4, the current flowing in the solenoid valve coil 40 upon applying a driving voltages V ₁ to the solenoid valve coil 40 when opening the solenoid valve 10, and the position of the main valve 30, and speed main valve 30 is moved, It is explanatory drawing showing the relationship of these. In FIG. 4, a solid line shows a state when the driving voltage V ₁ is applied to the electromagnetic valve coil 40 under a predetermined condition. At this time, by applying a driving voltages V ₁ to the solenoid valve coil 40, flows through current I _A to the solenoid valve coil 40. In FIG. 4, the timing for starting the application of the drive voltage V ₁ is shown as time t ₀ . When energization of the electromagnetic valve coil 40 is started in this manner, as described above, first, the pilot valve 20 is opened, and after the inside of the communication flow path 46 starts to be pressurized, the main valve 30 is opened. In FIG. 4, the timing at which the main valve 30 starts to open is shown as time t ₁ . In FIG. 4, the timing at which the main valve 30 collides with the stopper 36 and stops moving is shown as time t ₃ . The main valve 30 that has started moving at time t ₁ gradually increases in speed until reaching the fully open position at time t ₃ , and reaches the maximum speed Sp _A when it collides with the stopper 36. In Figure 4, the time at the valve opening begins (at the beginning of the application of the drive voltages V ₁ to the electromagnetic valve coil 40) until the open ends, is shown as the response time T _A.

Here, even if the magnitude of the drive voltage V ₁ applied to the solenoid valve coil 40 is the same, the current value flowing varies depending on the conditions of the solenoid valve coil 40. Specifically, the temperature of the solenoid valve coil 40 is changed, so that when the resistance value of the solenoid valve coil 40 is changed, the current flowing even when applying the same driving voltages V ₁ changes. FIG. 4 shows the case where the current flowing through the solenoid valve coil 40 when the valve is opened is small I _B than I _A with a broken line. When the current flowing through the solenoid valve coil 40 is small as described above, the suction force Fab generated by the solenoid valve coil 40 is also reduced, so that the opening speed of the pilot valve 20 is reduced. As a result, it takes time to increase the pressure on the communication flow path 46 side, and the timing at which the main valve 30 starts to open is a time t ₂ that is later than the time t ₁ . Further, when the current flowing through the solenoid valve coil 40 is small, the suction force Fab generated by the solenoid valve coil 40 is also small, so that the valve opening speed of the main valve 30 is also slowed. As a result, the timing of the opening end, a slow time t ₄ than the time t _3. At this time, the maximum speed Sp _B of the main valve 30 at the end of the valve opening is slower than the above-described maximum speed Sp _A. In Figure 4, the current flowing through the solenoid valve coil 40 when the valve is opened is when it is I _B, the time required from when the valve is opened start to the opening ends, is shown as the response time T _B.

Incidentally, when determining the response time described above is a time until the opening ends from (starting application of the drive voltages V ₁ to the electromagnetic valve coil 40) open at the start, when the valve opens terminated, for example, the main Although it may be specified by directly detecting the position of the valve 30, in this embodiment, it is specified based on the hydrogen gas pressure in the flow path. Specifically, a first pressure sensor (not shown) that measures the pressure in the first through hole 44 and a second pressure sensor (not shown) that measures the pressure in the communication channel 46 are provided, and the first and first The time point at which the detected values of the pressure sensors 2 are equal is specified as the valve opening end time.

FIG. 5 is an explanatory diagram showing the relationship between the current flowing through the electromagnetic valve coil 40 when the valve is opened and the sound pressure level of the sound generated when the main valve 30 collides with the stopper 36 when the valve is opened. As shown in FIG. 5, the sound pressure level Sd _α when the current flowing when the drive voltage V ₁ is applied is I _α is higher than the sound pressure level Sd _β when a current I _β larger than I _α flows. Becomes smaller. As explained based on FIG. 4, it is considered that the smaller the value of the current flowing through the solenoid valve coil 40 is, the slower the speed of the main valve 30 at the end of the valve opening. Therefore, in order to suppress the sound pressure level when the valve is opened, it can be said that the current flowing through the solenoid valve coil 40 should be reduced when the valve is opened.

  Here, in the solenoid valve 10, when the solenoid valve 10 repeats the opening / closing valve and the main valve 30 repeatedly collides with the main valve seat 32, the main valve seat 32 gradually becomes thinner and the main valve 30 moves when the valve is opened. The distance to do becomes longer gradually. In FIG. 1, the distance between the main valve 30 and the stopper 36, which is the distance that the main valve 30 moves when the valve is opened, is shown as an air gap.

  When the air gap changes in this way, the distance between the closed position and the fully opened position of the main valve 30 shown in FIG. 4 gradually increases, and even if the current value flowing through the electromagnetic valve coil 40 is the same, The speed at which the main valve 30 collides with the stopper 36 when the valve is opened gradually increases. As a result, the sound pressure level of the sound generated when the solenoid valve 10 is opened increases. Therefore, in this embodiment, the sound pressure generated at the time of valve opening is suppressed to an allowable range by controlling the current flowing through the electromagnetic valve coil 40 at the time of valve opening while considering the change of the air gap. Below, the specific operation | movement which concerns on control of the electric current value sent through the solenoid valve coil 40 is demonstrated.

(A-3) Solenoid valve opening control:
FIG. 6 is a flowchart showing a valve opening control processing routine executed by the control unit 50 during valve opening control of the electromagnetic valve 10. This routine is started and executed when the opening of the solenoid valve 10 is requested.

When this routine is started, the control unit 50 acquires the time of applying a driving voltage V _1, the relationship between the current and the response time when the valve opening (step S100). The solenoid valve coil 40 repeats the start and stop of energization, so that the temperature rises and falls and the resistance value always fluctuates. In the present embodiment, a current meter (not shown) to the solenoid valve coil 40, each for applying a driving voltages V ₁ to the solenoid valve coil 40, measures the current flowing to the solenoid valve coil 40. Also, each time applying a driving voltages V ₁ to the solenoid valve coil 40, measures the response time from the valve opening start to the opening ends. As described above, the control unit 50 derives the relationship between the current value and the response time while repeatedly acquiring the current value and the response time in accordance with the on-off valve control, and continuously updates the derived relationship. doing.

  FIG. 7 is an explanatory diagram illustrating an example of the relationship between the current value and the response time obtained based on data obtained by actually measuring the current value and the response time when the valve opening control of the electromagnetic valve 10 is repeated. In this embodiment, the relationship between the current value and the response time is linearly approximated (fitted) by the least square method, but a different approximation method may be adopted. As described above, in the electromagnetic valve 10, the main valve seat 32 is deformed and the air gap is expanded by repeating the valve opening operation. However, the relationship between the current value derived in step S100 and the response time is the air Within a limited period (for example, a limited range of valve opening times) in which the gap does not substantially change, a certain relationship is shown as linearly approximated in FIG. In the present embodiment, the current and response time when the valve is opened within a limited range in which the air gap does not substantially change while repeatedly acquiring the current value and the response time along with the repetition of the on-off valve control of the electromagnetic valve 10. The relationship between is constantly updated. In step S100, the latest relationship updated in this way is acquired. Step S100 includes “first step” in “means for solving the problem”.

Next, the control unit 50 on the basis of the obtained relationship in step S100, the solenoid valve coil 40, to derive the response time _{T A} when flowing a predetermined current value _{I A} a predetermined (step S110). 7, based on the relationship between the response time and the current value linearly approximated, showing how to derive the response time T _A when the current flow value I _A to the solenoid valve coil 40.

Then, based on the response time _{T A} derived in step S110, it derives the current air gap _{G A} (step S120).

8, when the current value flowing to the solenoid valve coil 40 when the valve is opened is I _A, is an explanatory diagram showing a relationship between response time and air gap. If the current value at the time of valve opening is constant, the response time becomes longer as the air gap becomes larger. In the present embodiment, as shown in FIG. 8, the relationship obtained in advance between the response time and the air gap when current flowing through the solenoid valve coil 40 when the valve is opened is I _A, the control unit as a map 50. In step S120, by referring to the map, to derive the air gap _{G A} corresponding to the response time _{T A} derived in step S110.

Then, based on the air gap _{G A} derived in step S120, an air gap when _{G A,} derives a target current value _{I Tara} the sound pressure level at the valve opening time becomes the allowable value (step S130).

9, the current flowing in the solenoid valve coil 40 when the valve is opened, and the sound pressure level of the sound main valve 30 is caused to collide with the stopper 36 when the valve is opened, the relationship between, and when the air gap is G _A is an explanatory diagram showing the case where G _B. As described with reference to FIG. 5, the greater the current flowing through the solenoid valve coil 40, the greater the sound pressure level when the valve is opened. Such a relationship between the current and the sound pressure level is determined for each size of the air gap. Specifically, the greater the air gap, the longer the distance that the main valve 30 moves when the valve is opened, and the final speed of the main valve 30 is increased, so that the sound pressure level is increased. In the present embodiment, the relationship between the current value flowing through the electromagnetic valve coil 40 and the sound pressure level is obtained in advance over the entire range of the assumed air gap, and is stored in the control unit 50 as a map and is allowable. A target sound pressure level Sd _tar which is the upper limit of the sound pressure level is set. In step S130, by referring to the map, under the conditions of the air gap _{G A} derived in step S120, derives a target current value _{I Tara} sound pressure level is a current value when the target sound pressure level _{Sd tar} To do. The operations from step S110 to step S130 correspond to the “second step” in “means for solving the problem”.

Next, the control unit 50 applies a small voltage V ₂ to the electromagnetic valve coil 40, to measure the current value I ₂ flowing through the solenoid valve coil 40 at that time, based on the result, the drive voltage V _A current value I _1-1 flowing through the solenoid valve coil 40 when ₁ is applied is derived (step S140). Minute voltage V ₂ applied in step S140 to the electromagnetic valve coil 40 is extremely small value as compared with the driving voltage V _1, is set as a value not to open the pilot valve 20. Under the condition that the temperature of the solenoid valve coil 40, that is, the resistance value of the solenoid valve coil 40 is the same, the drive voltage V ₁ is determined based on Ohm's law by measuring the current value I ₂ with respect to the minute voltage V ₂ . It is possible to calculate the current value I _1-1 that flows through the solenoid valve coil 40 when is applied.

After step S140, the control unit 50 compares the current value I _1-1 derived in step S140 with the target current value I _tarA derived in step S130 (step S150). When the current value I _1-1 is equal to or less than the target current value I _tarA , even if the drive voltage V ₁ is applied to the solenoid valve coil 40, the sound pressure of the generated sound is less than or equal to the allowable sound pressure level Sd _tar. I can judge. Therefore, in this case, the control unit 50 starts the operation of the valve opening by applying a driving voltages V ₁ to the solenoid valve coil 40 (step S180), and terminates this routine. In step S150 in FIG. 6, the current value derived for comparison with the target current value I _tarA is considered in consideration of the case where the operation of measuring the current value by applying the minute voltage V2 is repeated as described later. I _1-x .

In step S150, the when the current value _{I 1-1} exceeds the target current value _{I Tara,} when applying a driving voltages _{V 1} to the solenoid valve coil 40, the sound pressure of the resulting sound exceeds an acceptable sound pressure level _{Sd tar} It can be judged. In this case, the control unit 50 continues to apply the minute voltage V2 (step S160).

FIG. 10 is an explanatory diagram showing the relationship between the temperature and resistance of the solenoid valve coil 40. FIG. 11 is an explanatory diagram showing the relationship between the resistance of the solenoid valve coil 40 and the current flowing through the solenoid valve coil 40 when the drive voltage V ₁ is applied to the solenoid valve coil 40. Further, FIG. 12 is an explanatory diagram showing when the air gap is G _A, the relationship between the sound pressure level of the sound generated during the current and open flowing through the solenoid valve coil 40. As shown in FIG. 10, the resistance of the solenoid valve coil 40 increases as the temperature of the solenoid valve coil 40 increases. Then, as shown in FIG. 11, the greater the resistance of the solenoid valve coil 40, current flowing through the solenoid valve coil 40 upon application of the driving voltages V ₁ decreases. As shown in FIG. 12, if the air gap is constant, the sound pressure level of the sound generated at the time of valve opening decreases as the current value flowing through the solenoid valve coil 40 decreases. By controlling unit 50 continues the application of the minute voltage V ₂ at step S160, elevated temperature and coil resistance of the solenoid valve coil 40, a current value flowing drops upon application of a driving voltage V _1. As a result, the sound pressure level of the sound that occurs when applying a driving voltage V ₁ is lowered. In FIG. 12 from FIG. 10, the direction of change due to the continuation of the application of the minute voltage V ₂ to the electromagnetic valve coils 40, are indicated by white arrows.

In step S160, after the application of the minute voltage V ₂ to the electromagnetic valve coil 40 for the predetermined period, the control unit 50 again measures the current value I ₂ flowing through the solenoid valve coil 40. Then, similarly to step S140, to derive the current value _{I 1-x} flowing through the solenoid valve coil 40 in the case of applying the driving voltage _{V 1} (step S170).

When the current value I _1-x is derived in step S170, the control unit 50 returns to step S150, and compares the current value I _1-x derived in step S170 with the target current value I _tarA derived in step S130. Then, in step S150 until the current value _{I 1-1} determines that exceeds the target current value _{I Tara,} repeats the operations of steps S160, S170, and S150. In Figure 12, continued application of minute voltage V ₂ to the electromagnetic valve coil 40, when a current value flowing upon application of a driving voltage V ₁ is lowered to I _1-x, sound generated when the valve is opened The sound pressure level of Sd _1-x is equal to or less than the allowable value Sd _tar . In step S150, the the current value _{I 1-1} is below the target current value _{I Tara,} the control unit 50 starts the operation of the valve opening by applying a driving voltages _{V 1} to the solenoid valve coil 40 (Step S180) This routine is terminated. The operation from step S140 to step S180 corresponds to the “third step” in “means for solving the problem”.

  According to the control method of the solenoid valve 10 of the present embodiment configured as described above, even when the air gap changes by continuing use of the solenoid valve 10, it occurs when the solenoid valve 10 is opened. The sound pressure level of the sound can be suppressed below an allowable value.

That is, the response to this embodiment, the current flowing through the solenoid valve coil 40 upon application of the driving voltages V ₁ to the solenoid valve coil 40, the main valve 30 is opened from the start of application of the drive voltages V ₁ Based on the updated relationship, the target current value I _tarA to be _passed through the solenoid valve coil 40 is derived based on the updated relationship. As described above, since the target current value I _tarA is derived based on the latest derived relationship described above, even when the air gap changes, the control for suppressing the sound pressure of the sound generated at the time of valve opening to an allowable value or less is appropriately performed. Can be done.

Further, according to this embodiment, before applying the driving voltages V ₁ to the solenoid valve coil 40, by applying a minute voltage V ₂ which does not open the pilot valve 20 occurs upon application of a driving voltages V ₁ The solenoid valve coil 40 is heated in advance so that the sound pressure of the sound is less than the allowable value. Therefore, unlike the case where further energization control (such as stopping energization at a specific timing) is performed after the drive voltage is applied to the solenoid valve coil to reduce the sound pressure of the sound generated when the valve is opened, the air gap is extremely Even in a narrow case, it is possible to satisfactorily control the sound pressure level. As a result, the entire solenoid valve is made compact, and the effect of lowering the sound pressure level when the valve is opened can be obtained particularly remarkably in a pilot solenoid valve in which the moving distance of the valve body is relatively short when the valve is opened. .

  Further, according to this embodiment, since the temperature of the solenoid valve coil 40 at the time of opening the valve is raised to suppress the current value, the attractive force Fab generated by the voltage application to the solenoid valve coil 40 can be suppressed. The speed at the time of 20 valve opening is suppressed. Therefore, not only the sound pressure level of the sound generated when the main valve 30 collides with the stopper 36 is lowered, but also high-pressure hydrogen gas is introduced into the communication channel 46 side through the orifice hole 38 when the pilot valve 20 is opened. The speed at the time of starting to flow can be suppressed, and the generated sound can be reduced. As a result, not only the sound generated when the main valve 30 collides with the stopper 36 but also the entire sound generated when the electromagnetic valve 10 is opened can be reduced.

In the first embodiment described above, at step S100, after acquiring the latest relationship between the current and response time at the valve opening at the time of applying a driving voltage V _1, steps S110 to step S130 These steps are sequentially performed, but different configurations may be employed. Based on the relationship between the current at the time of the acquired open and response time in step S100, the response time T _A when flowing current I _A to the solenoid valve coil _40, the air gap G _A, and the target current value I _Tara is Kazuyoshi (See FIGS. 7 to 9). Therefore, for example, the relationship between the response time T _A and the target current value I _tarA is mapped in advance and stored in the control unit 50, and the target current value I _tarA is _calculated based on the response time T _A derived in step S110. It may be derived directly.

In the first embodiment, the current value I _1-x derived from the current value when the minute voltage V ₂ is applied is compared with the target current value I _tarA in step S150 of FIG. However, a different configuration may be used. For example, after deriving the current value I _1-x when the drive voltage V ₁ is applied based on the current value when the minute voltage V ₂ is applied in step S 140 or step S 170, the air gap derived in step S 120 based on the relationship shown in G _a and 9, to derive the sound pressure level of the sound generated when a driving voltage is applied V _1. In step S150, the derived sound pressure level may be compared with the target sound pressure level Sd _tar .

B. Second embodiment:
FIG. 13 is a flowchart showing a valve opening control processing routine that is activated and executed when the opening of the electromagnetic valve 10 is requested in the electromagnetic valve 10 according to the second embodiment of the present invention. Since the second embodiment relates to the valve opening control of the electromagnetic valve 10 having the same configuration as that of the first embodiment, detailed description regarding the configuration of the electromagnetic valve 10 is omitted. In FIG. 13, steps common to those in FIG. 6 are given the same step numbers, and detailed description thereof is omitted. In the second embodiment, unlike the first embodiment, the timing for applying the drive voltage V ₁ is determined based on the temperature of the solenoid valve coil 40 instead of the current value that flows when the minute voltage V ₂ is applied. doing.

When this routine is started, the control unit 50, as in the first embodiment, when a driving voltage is applied V _1, the latest relationship between the current and the response time is obtained (step S100) to derive the response time _{T a} corresponding to the current value _{I a} on the basis of this relationship (step S110), further derives the current air gap _{G a} (step S120). Then, we derive the target coil temperature _{Tem Tara} the air gap becomes a sound pressure level tolerance when _{G A} (step S230).

FIG. 14 is an explanatory diagram showing the relationship between the temperature of the solenoid valve coil 40 and the current flowing through the solenoid valve coil 40 when the drive voltage V ₁ is applied to the solenoid valve coil 40. Since the resistance value of the solenoid valve coil 40 increases as the temperature of the solenoid valve coil 40 increases, the value of the current flowing through the solenoid valve coil 40 decreases (see FIGS. 10 and 11). Thus, the relationship between the temperature of the solenoid valve coil 40, the current flowing through the solenoid valve coil 40 upon application of the driving voltages V ₁ to the solenoid valve coil 40 is uniquely determined. Further, as shown in FIG. 12, the relationship between the current flowing through the solenoid valve coil 40 upon application of the driving voltages V ₁ to the solenoid valve coil 40, the sound pressure level of the sound generated during the opening of the solenoid valve 10, It is uniquely determined for each size of the air gap. In the present embodiment, the relationship between the temperature of the electromagnetic valve coil 40 and the sound pressure level at the time of valve opening is obtained in advance over the entire range of the assumed air gap, and is stored in the control unit 50 as a map. A target sound pressure level Sd _tar that is an upper limit of an allowable sound pressure level is set. At step S230, the by referring to the map, under the conditions of the air gap G _A derived in step S120, the target coil temperature is a temperature of the solenoid valve coil 40 when the sound pressure level is a target sound pressure level Sd _{tar Derive} Tem _tarA . The operations from step S110 to step S230 correspond to the “second step” in “means for solving the problem”.

Next, the control unit 50 measures the coil temperature Tem _2-1 of the electromagnetic valve coil 40 (step S240). Specifically, the solenoid valve 10 of this embodiment is provided with a temperature sensor (not shown) that measures the temperature of the solenoid valve coil 40. In step S240, a detection signal of the temperature sensor is acquired.

After step S240, the control unit 50 compares the coil temperature Tem _2-1 acquired in step S240 with the target coil temperature Tem _tarA derived in step S230 (step S250). When the coil temperature Tem _2-1 is equal to or lower than the target coil temperature Tem _tarA , even if the drive voltage V ₁ is applied to the electromagnetic valve coil 40, the sound pressure of the generated sound is equal to or lower than the allowable sound pressure level Sd _tar. I can judge. Therefore, in this case, the control unit 50 starts the operation of the valve opening by applying a driving voltages V ₁ to the solenoid valve coil 40 (step S180), and terminates this routine. In step S250 of FIG. 13, in consideration of the case of repeating the operation of measuring the coil temperature while applying a small voltage V ₂ as will be described later, the coil temperature obtained for comparison with the target coil temperature Tem _Tara , Tem _2-x .

In step S250, when the coil temperature Tem _2-1 exceeds the target coil temperature Tem _tarA , when the drive voltage V ₁ is applied to the solenoid valve coil 40, the sound pressure of the generated sound exceeds the allowable sound pressure level Sd _tar . It can be judged. In this case, the control unit 50 starts the application of the minute voltage _{V 2} to the electromagnetic valve coil 40 (step S260). Here, the minute voltage V ₂ is an extremely small value compared to the drive voltage V ₁ as in the first embodiment, and is set as a value that does not open the pilot valve 20. By initiating the application of the minute voltage V ₂ to the electromagnetic valve coil 40, the electromagnetic valve coil 40 is gradually raising the temperature.

As shown in FIG. 14 already described, as the temperature of the solenoid valve coil 40 is increased, so the resistance of the solenoid valve coil 40 is large, the current value flowing through the solenoid valve coil 40 upon application of a driving voltage V ₁ is Get smaller. As shown in FIG. 12, if the air gap is constant, the sound pressure level of the sound generated at the time of valve opening decreases as the current value flowing through the solenoid valve coil 40 decreases. By the control unit 50 performs the application of the minute voltage V ₂ at step S260, elevated temperature and coil resistance of the solenoid valve coil 40, a current value flowing drops upon application of a driving voltage V _1. As a result, the sound pressure level of the sound that occurs when applying a driving voltage V ₁ is lowered. In FIG. 14, the direction of change due to the continuation of the application of the minute voltage V ₂ to the electromagnetic valve coils 40, are indicated by white arrows.

In step S260, after the application of the minute voltage _{V 2} to the electromagnetic valve coil 40 for the predetermined period, the control unit 50 again measures the coil temperature _{Tem 2-x} of the solenoid valve coil 40 (step S270). When the coil temperature Tem _2-x is measured in step S270, the control unit 50 returns to step S250 and compares the coil temperature Tem _2-x measured in step S270 with the target coil temperature Tem _tarA derived in step S230. Then, the operations of steps S260, S270, and S250 are repeated until it is determined in step S250 that the coil temperature Tem _2-x exceeds the target coil temperature Tem _tarA . In step S250, the coil temperature _{Tem 2-x} is less than the target coil temperature _{Tem Tara,} the control unit 50 starts the operation of the valve opening by applying a driving voltages _{V 1} to the solenoid valve coil 40 (Step S180) This routine is terminated. The operation from step S240 to step S280 corresponds to the “third step” in “means for solving the problem”.

  The same effect as that of the first embodiment can be obtained also by the valve opening control method of the electromagnetic valve 10 of the second embodiment configured as described above.

C. Variations:
・ Modification 1:
The solenoid valve to which the solenoid valve control method according to the present application is applied may be a pilot solenoid valve having a configuration different from that of the solenoid valve 10 shown in FIGS. Further, for example, a direct acting solenoid valve may be used which is different from the pilot type. As with the solenoid valve 10, the air gap (the travel distance of the valve body when the valve is opened) changes as the operation of the on-off valve is repeated, and the valve body movement speed when the valve is opened is adjusted by the current flowing through the solenoid valve coil. If possible, the same effect can be obtained by applying the valve opening control method according to the present invention.

Modification 2
In each of the embodiments described above, the solenoid valve 10 is provided in a hydrogen flow path for supplying hydrogen from a hydrogen tank to a fuel cell in a fuel cell vehicle equipped with a fuel cell system including a hydrogen tank and a fuel cell. However, different configurations may be used. The solenoid valve to which the solenoid valve control method according to the present invention is applied may be attached to a device other than the fuel cell system, or may be disposed in a fluid flow path other than hydrogen gas.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Solenoid valve 20 ... Pilot valve 22 ... Pilot valve seat 24 ... Pilot valve spring 26 ... 2nd through-hole 30 ... Main valve 32 ... Main valve seat 34 ... Main valve spring 36 ... Stopper 38 ... Orifice hole 39 ... Partition part 40 ... Solenoid valve coil 41 ... Communication space 42 ... Housing 43 ... Pilot space 44 ... First through hole 46 ... Communication flow path 50 ... Control part

Claims (1)

A method for controlling an electromagnetic valve comprising a valve body, a valve seat, and a coil, wherein the valve body seated on the valve seat is opened by being separated from the valve seat by applying a voltage to the coil,
Data including a current value that flows through the coil when a predetermined specific driving voltage is applied to the coil, and a response time from when the application of the driving voltage is started until the valve element opens. The first step of deriving the relationship between the current value and the response time while repeatedly acquiring, and continuously updating the derived relationship with the opening and closing operation of the solenoid valve;
When opening of the solenoid valve is requested, based on the updated relationship, the volume of sound generated when the solenoid valve is opened by applying the drive voltage to the coil becomes an allowable value. A second step of deriving a target current value that is a current value flowing through the coil or a target temperature that is a temperature of the coil;
When the target current value is derived in the second step, a minute voltage that is smaller than the drive voltage and does not open the solenoid valve is applied to the coil, and the drive voltage is applied to the coil. When it is applied, the application of the minute voltage is continued until it is determined that the current flowing through the coil is equal to or lower than the target current value, and then the drive voltage is applied to the coil to open the solenoid valve. When the target temperature is derived in the second step, the minute voltage is applied to the coil until the coil temperature reaches the target temperature, and then the drive voltage is applied to the coil. A third step of opening the solenoid valve;
A method for controlling a solenoid valve.

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