Solenoid valve control device

Abstract

To improve operation responsiveness of a solenoid valve.SOLUTION: A control device 100 of a solenoid valve for controlling opening / closing of the solenoid valve 1 having electromagnet and a valve element moving to the electromagnet by electromagnetic force includes: a water temperature sensor 19 and a temperature determination unit 31 for detecting a temperature of the solenoid valve 1; and an energization control unit 32 for controlling the solenoid valve 1 so that electric current intermittently flows to the solenoid valve 1 by PWM control in a case when a temperature detected by the water temperature sensor 19 and the temperature determination unit 31 is a prescribed temperature or less, and the electric current continuously flows to the solenoid valve 1 in a case when the temperature detected by the water temperature sensor 19 and the temperature determination unit 31 is higher than the prescribed temperature, in moving the valve element.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device for a solenoid valve that controls the opening and closing of a solenoid valve. [Background technology]

[0002] Conventionally, solenoid valves that open and close a flow path by moving a valve element using electromagnetic force are known (see, for example, Patent Document 1). The solenoid valve described in Patent Document 1 has a case that houses a spring, electromagnet, etc. that biases the valve element in a valve closing direction, a valve element that moves in a valve opening direction in response to excitation of the electromagnet, and a flexible seal ring that seals the gap between the case and the valve element. A communication hole is formed in this valve element, and when the valve is closed, high-pressure fluid flows into the case through the communication hole and expands the seal ring, so that the seal ring makes contact with the case and the valve element without any gaps, thereby improving sealing performance.

[0003] Solenoid valves can be applied to vehicle components such as air bypass valves. Ensuring the operational responsiveness of solenoid valves as vehicle components can improve vehicle safety and contribute to the development of sustainable transportation systems. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 026069 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the solenoid valve described in Patent Document 1, there is a risk that the operational response will decrease if the flexibility of the seal ring decreases in a low-temperature environment. [Means for solving the problem]

[0006] One aspect of the present invention is a control device for a solenoid valve that controls the opening and closing of a solenoid valve having an electromagnet and a valve element that moves relative to the electromagnet by electromagnetic force, the control device including a temperature detection unit that detects the temperature of the solenoid valve, and a PWM control that controls the solenoid valve when the temperature detected by the temperature detection unit is equal to or lower than a predetermined temperature when the valve element is moved. By applying the power supply voltage intermittently, the current flowing through the coil and the electromagnetic force increase and decrease. Applying current intermittently At the same time, the duty ratio of the PWM control is changed so that the average value of the voltage input to the solenoid valve increases continuously. On the other hand, the device includes a control unit that controls the solenoid valve so that a current flows continuously through the solenoid valve when the temperature detected by the temperature detection unit is higher than the predetermined temperature. [Effects of the Invention]

[0007] According to the present invention, the operational response of the solenoid valve can be improved. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a cross-sectional view showing an example of a configuration of a solenoid valve to which a control device for a solenoid valve according to an embodiment of the present invention is applied and its surroundings when a flow path is closed. [Figure 1B] 1 is a cross-sectional view showing an example of a configuration of a solenoid valve to which a control device for a solenoid valve according to an embodiment of the present invention is applied and its surroundings when a flow path is opened; [Figure 2] 1C is a diagram for explaining an application example of the solenoid valve of FIG. 1A and FIG. 1B. [Figure 3] 1 is a block diagram showing a schematic configuration of a main part of a control device for a solenoid valve according to an embodiment of the present invention; [Figure 4] 1C is a diagram for explaining the valve opening degree when the energization method for the solenoid valve of FIG. 1A and FIG. 1B is switched. [Figure 5] 3 is a flowchart showing an example of processing executed by the control device for a solenoid valve according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1A to 5. Figures 1A and 1B are cross-sectional views that schematically show an example of a solenoid valve 1 to which a solenoid valve control device according to an embodiment of the present invention is applied, and a configuration of its periphery. Figure 1A shows a state when the solenoid valve 1 closes a flow path 10, and Figure 1B shows a state when the solenoid valve 1 opens the flow path 10.

[0010] 1A and 1B, solenoid valve 1 has a fixed core 2 and a coil 3 wound around fixed core 2. The fixed core 2 and coil 3 form an electromagnet, which generates electromagnetic force in response to the passage of current through coil 3. Solenoid valve 1 further has a movable core 4 that is attracted to the fixed core 2 in response to the electromagnetic force generated when current is passed through coil 3, a valve element 5 attached integrally with movable core 4, and a spring 6 that biases valve element 5 in the direction opposite to the direction of attraction due to the electromagnetic force.

[0011] 1A, when the solenoid valve 1 (coil 3) is not energized, the biasing force of the spring 6 causes the valve element 5 to seat on a seating surface 10a formed in the flow path 10, thereby closing the flow path 10. On the other hand, as shown in FIG. 1B, when the solenoid valve 1 is energized, the electromagnetic force of the electromagnet (fixed core 2, coil 3) attracts the movable core 4 and the valve element 5 toward the fixed core 2, and the valve element 5 moves in a direction away from the seating surface 10a against the biasing force of the spring 6, thereby opening the flow path 10.

[0012] 1A and 1B, the solenoid valve 1 further includes a housing 7 having an opening 7a through which the valve element 5 is inserted and removed, a seal ring 8 that seals the gap between the housing 7 and the valve element 5, and a holder 9 that holds the seal ring 8. The housing 7 accommodates the fixed core 2, the coil 3, the bobbin 3a around which the coil 3 is wound, the movable core 4, the guide 4a that guides the movable core 4, the spring 6, the seal ring 8, and the holder 9.

[0013] The seal ring 8 is made of a flexible resin material such as a fluororesin (for example, PTFE (Poly Tetra Fluoro Ethylene)) and has a U-shaped or V-shaped cross section. The seal ring 8 is placed on the housing 7 so that the recess 8a in the cross section faces the internal space SP1 of the housing 7, and is held by a holder 9.

[0014] The valve element 5 has a communication hole 5a that communicates the internal space SP1 of the housing 7 with the external space SP2. When the pressure in the external space SP2 that communicates with the internal space SP1 is high when the solenoid valve 1 is closed ( FIG. 1A ), the high-pressure fluid flowing in through the communication hole 5a causes the seal ring 8 to bend so that the recess 8a is expanded, resulting in tight contact between the housing 7 and the valve element 5. While this improves the sealing performance of the solenoid valve 1 in the closed state, in a low-temperature environment (e.g., about −30° C.) where the flexibility of the resin material that makes up the seal ring 8 decreases (the hardness increases), the operational responsiveness when opening the valve from the closed state decreases. In other words, in a low-temperature environment where the flexibility of the resin material that makes up the seal ring 8 decreases, friction due to contact and sliding between the valve element 5 and the seal ring 8 increases, making the operational responsiveness more likely to decrease.

[0015] 2 is a diagram for explaining an application example of the solenoid valve 1, and shows an example in which the solenoid valve 1 is used as an air bypass valve for an engine 11 having a supercharger. As shown in FIG. 2, the engine 11 is configured as an internal combustion engine such as a gasoline engine or a diesel engine, and is configured as an on-board engine mounted on a vehicle 20, for example. The engine 11 is provided with a water temperature sensor 19 that detects the temperature (engine water temperature) TW of the cooling water of the engine 11. Connected to the engine 11 are an intake passage 12 through which intake air (intake air) drawn into the engine 11 passes, and an exhaust passage 13 through which exhaust gas (exhaust gas) burned by the engine 11 passes.

[0016] A turbine 14a that is rotationally driven by exhaust gas is provided in the exhaust passage 13. A compressor 14b that is provided coaxially with the turbine 14a and compresses intake air at atmospheric pressure P1 that is drawn in via an air cleaner (not shown) to a supercharging pressure P2 is provided in the intake passage 12. In other words, the turbine 14a and the compressor 14b form a supercharger 14 that supercharges the intake air.

[0017] The exhaust passage 13 is provided with bypass passages 15 that divert the exhaust gas from the upstream side of the turbine 14a to the downstream side thereof, and the bypass passage 15 is provided with a wastegate valve 16 that opens and closes the bypass passage 15. By adjusting the opening of the wastegate valve 16, the flow rate of the exhaust gas passing through the turbine 14a can be adjusted, the rotation speeds of the turbine 14a and the compressor 14b can be adjusted, and the supercharging pressure P2 by the supercharger 14 can be adjusted.

[0018] An intercooler 17 that cools the intake air (supercharged air) compressed by the compressor 14b and a throttle valve 18 that adjusts the amount of intake air are provided in the intake passage 12 downstream of the compressor 14b. By adjusting the opening of the throttle valve 18, the amount of intake air to the engine 11 can be adjusted, and the load (output) of the engine 11 can be adjusted.

[0019] A flow path 10 is provided in the intake passage 12 upstream of the compressor 14b and downstream of the intercooler 17 and upstream of the throttle valve 18 as an air bypass passage for returning the boosted air compressed by the compressor 14b to the upstream of the compressor 14b. A solenoid valve 1 is provided in the flow path 10 as an air bypass valve for opening and closing the flow path 10, and a seating surface 10a (FIGS. 1A and 1B) on which the valve element 5 of the solenoid valve 1 seats is formed on the inner wall of the flow path 10.

[0020] When the vehicle 20 is running and the accelerator is on, the throttle valve 18 is opened to an appropriate opening degree according to the engine load, and intake air that has passed through the compressor 14b and the intercooler 17 is supplied to the engine 11. More specifically, in the naturally aspirated region where the engine load is low, intake air at atmospheric pressure P1 is drawn into the engine 11, and in the supercharged region where the engine load is high, intake air (supercharged air) at supercharging pressure P2 compressed by the supercharger 14 is pressure-fed to the engine 11. At this time, no current is applied to the solenoid valve 1, and the solenoid valve 1 maintains a closed state ( FIG. 1A ) in which the valve element 5 is seated on a seating surface 10a on the inner wall of the flow path 10 due to the biasing force of the spring 6, thereby maintaining the flow path 10 in a closed state.

[0021] 1A and 2, in the supercharging region, supercharged air from the external space SP2 communicating with the intake passage 12 downstream of the compressor 14b flows into the internal space SP1 of the solenoid valve 1 through the communication hole 5a, and deflects the seal ring 8 so as to expand the recess 8a. This brings the seal ring 8 into tight contact with the housing 7 and the valve body 5, reliably preventing leakage of supercharged air from the intake passage 12 downstream of the compressor 14b to the intake passage 12 upstream of the compressor 14b, and appropriately maintaining the supercharging pressure P2.

[0022] On the other hand, when the accelerator is released during deceleration of the vehicle 20, the throttle valve 18 is immediately closed and the solenoid valve 1 is energized, causing the solenoid valve 1 to transition to an open state (FIG. 1B). At this time, the electromagnetic force generated by energizing the coil 3 attracts the movable core 4 and the valve element 5 toward the fixed core 2, and the valve element 5 moves in a direction away from the seating surface 10a on the inner wall of the flow path 10 against the biasing force of the spring 6, thereby opening the flow path 10. When the flow path 10 is opened, the supercharged air downstream of the compressor 14b is returned via the flow path 10 to the upstream of the compressor 14b, thereby releasing the supercharging pressure P2.

[0023] However, in a low-temperature environment where the flexibility of the resin material composing the seal ring 8 decreases, friction due to contact and sliding between the valve element 5 and the seal ring 8 increases, the electromagnetic force generated by energizing the coil 3 becomes relatively insufficient, and the operational responsiveness when the valve element 5 moves decreases. In this case, a delay occurs between the closing of the throttle valve 18 and the opening of the flow path 10 to release the supercharging pressure P2, and excessive supercharged air accumulates in the intake passage 12 downstream of the compressor 14b, which may cause surging of the supercharger 14.

[0024] When surging of the turbocharger 14 occurs, abnormal noise due to surging may be generated, which may impair the acoustic commercial value of the engine 11. Furthermore, since components such as the blades of the turbine 14a may be damaged, the engine 11 needs to be highly durable, which increases costs. Therefore, in this embodiment, the solenoid valve control device is configured as follows so as to ensure operational responsiveness when moving the valve element 5 by switching the method of energizing the solenoid valve 1 in a low-temperature environment.

[0025] Fig. 3 is a block diagram showing a schematic configuration of the main components of a solenoid valve control device (hereinafter referred to as device) 100 according to an embodiment of the present invention. As shown in Fig. 3, the device 100 mainly includes a controller 30, a solenoid valve 1, and a water temperature sensor 19, each of which is communicatively connected to the controller 30. The controller 30 is configured as an electronic control unit including a computer having a CPU, ROM, RAM, and other peripheral circuits. The controller 30 functions as a temperature determination unit 31 and a current control unit 32.

[0026] The temperature determination unit 31 determines whether the solenoid valve 1 is in a predetermined low-temperature environment where the flexibility of the resin material that makes up the seal ring 8 decreases, based on the engine water temperature TW detected by the water temperature sensor 19. In other words, the water temperature sensor 19 and the temperature determination unit 31 constitute a temperature detection unit that detects the engine water temperature TW, which represents the temperature of the solenoid valve 1, and estimates whether the temperature of the solenoid valve 1 is low or not, based on the detected engine water temperature TW.

[0027] More specifically, the temperature determination unit 31 determines that the solenoid valve 1 is in a predetermined low-temperature environment until a predetermined time has elapsed after the engine water temperature TW detected by the water temperature sensor 19 has reached a predetermined water temperature TW0. Furthermore, when a predetermined time has elapsed after the engine water temperature TW has reached the predetermined water temperature TW0, the temperature determination unit 31 determines that the solenoid valve 1 is not in a predetermined low-temperature environment.

[0028] In this way, it is possible to simplify the configuration of the solenoid valve 1 because it is determined whether or not the solenoid valve 1 is in a predetermined low temperature environment based on the engine water temperature TW detected by the water temperature sensor 19, without providing a temperature sensor in the solenoid valve 1. Furthermore, by determining that the solenoid valve 1 is in a predetermined low temperature environment until a predetermined time has elapsed even after the engine water temperature TW has reached the predetermined water temperature TW0, it is possible to conservatively estimate the low temperature state of the solenoid valve 1.

[0029] The current control unit 32 controls the opening and closing of the solenoid valve 1 as an air bypass valve in response to an operation command for the solenoid valve 1 issued in response to the accelerator opening degree of the vehicle 20, etc. More specifically, when the temperature determination unit 31 determines that the solenoid valve 1 is in a predetermined low temperature environment, the current control unit 32 controls the solenoid valve 1 by PWM (Pulse Width Modulation) control in response to the operation command for the solenoid valve 1 so that current flows intermittently to the solenoid valve 1. On the other hand, when the temperature determination unit 31 determines that the solenoid valve 1 is not in the predetermined low temperature environment, the current control unit 32 controls the solenoid valve 1 in response to the operation command for the solenoid valve 1 so that current flows continuously to the solenoid valve 1.

[0030] Figure 4 is a diagram for explaining the valve opening degree when the method of energizing the solenoid valve 1 is switched. When the solenoid valve 1 is not in a predetermined low-temperature environment, such as after the engine 11 has been warmed up, as shown by the solid line in Figure 4, when an operation command for the solenoid valve 1 is input at time t1, a constant power supply voltage is immediately applied to the solenoid valve 1, and the solenoid valve 1 is controlled so as to continuously pass current (normal control). Power is supplied to the solenoid valve 1 from a battery or the like mounted on the vehicle 20, and the constant power supply voltage is continuously applied, causing current to continuously pass through the coil 3 of the solenoid valve 1.

[0031] When the solenoid valve 1 is not in a predetermined low-temperature environment, such as after the engine 11 has been warmed up, the valve element 5 quickly moves away from the fully closed position (FIG. 1A) where it is seated on the seating surface 10a in response to the electromagnetic force generated by energizing the coil 3, and reaches the fully open position (FIG. 1B) at time t3. This opens the flow path 10 in FIG. 2, and the boost air is returned from downstream of the compressor 14b to upstream of the compressor 14b, quickly releasing the boost pressure P2.

[0032] On the other hand, when the solenoid valve 1 is in a specified low-temperature environment, friction due to contact and sliding between the valve disc 5 and seal ring 8 increases, resulting in a relative insufficiency of the electromagnetic force generated by energizing the coil 3. If normal control is performed in such a case, the friction due to contact between the valve disc 5 and seal ring 8 increases compared to when the solenoid valve 1 is not in a specified low-temperature environment, and therefore movement of the valve disc 5 relative to the seal ring 8 is hindered until time t2, as shown by the dashed line in Figure 4.

[0033] Furthermore, since the friction caused by the sliding between the valve element 5 and the seal ring 8 is greater than when the solenoid valve 1 is not in a predetermined low-temperature environment, the movement speed of the valve element 5 decreases, and the time required for it to reach the fully closed position (FIG. 1A) to the fully open position (FIG. 1B) becomes longer (times t2 to t6). In this case, the time required from when the throttle valve 18 in FIG. 2 is closed until the flow path 10 is opened and the supercharging pressure P2 is released becomes longer, so that excessive supercharged air may accumulate in the intake passage 12 downstream of the compressor 14b, which may cause surging of the supercharger 14. Note that when the valve element 5 starts to move, frictional heat is generated by the sliding between the valve element 5 and the seal ring 8, reducing the friction on the sliding surfaces, and the movement speed of the valve element 5 increases (time t5).

[0034] When the temperature determination unit 31 determines that the solenoid valve 1 is in a predetermined low temperature environment, the current control unit 32 controls the solenoid valve 1 by PWM control so that current flows intermittently through the solenoid valve 1, as shown by the dotted line in Fig. 4. In PWM control, a switching element such as a transistor provided between the solenoid valve 1 and a power source such as a battery mounted on the vehicle 20 is switched on and off at a constant cycle (frequency) using a PWM signal that controls the time ratio (duty ratio) between current flow and non-current flow.

[0035] As a result, a constant power supply voltage is intermittently applied to the solenoid valve 1, and current flows intermittently through the coil 3 of the solenoid valve 1 (time t1 to time t4). More specifically, when the switching element is turned on, the current flowing through the coil 3 of the solenoid valve 1 increases, and when the switching element is turned off, the current flowing through the coil 3 of the solenoid valve 1 decreases. In the example of Figure 4, by changing the duty ratio from 0% to 100%, the average value of the voltage input to the solenoid valve 1 is changed continuously from 0% to 100% of the power supply voltage.

[0036] In this case, when an operation command for the solenoid valve 1 is input at time t1, PWM control is immediately initiated, and the electromagnetic force generated by energization increases or decreases in accordance with the increase or decrease in the current flowing through the coil 3, causing the valve element 5 to repeatedly move slightly at regular intervals relative to the seal ring 8. That is, as the electromagnetic force increases, the valve element 5 moves slightly away from the seating surface 10a, and as the electromagnetic force decreases, the valve element 5 moves slightly toward the seating surface 10a, and these small movements are repeated at regular intervals. When the valve element 5 repeatedly moves slightly at regular intervals relative to the seal ring 8, frictional heat is generated due to the sliding between the valve element 5 and the seal ring 8, and the flexibility of the resin material constituting the seal ring 8 increases (the hardness decreases), thereby reducing the friction on the sliding surfaces (times t1 to t2).

[0037] When the electromagnetic force exceeds the biasing force of the spring 6 at time t2, the valve disc 5 begins to move in small increments relative to the seal ring 8. That is, as the electromagnetic force increases and exceeds the biasing force of the spring 6, the valve disc 5 moves in a direction away from the seating surface 10a, and as the electromagnetic force decreases and falls below the biasing force of the spring 6, the valve disc 5 moves in a direction approaching the seating surface 10a. When the valve disc 5 moves in small increments relative to the seal ring 8 at a constant interval, frictional heat is generated due to the sliding between the valve disc 5 and the seal ring 8, and the flexibility of the resin material that makes up the seal ring 8 improves (hardness decreases), thereby reducing the friction on the sliding surfaces (times t2 to t4).

[0038] In this way, under PWM control, the valve element 5 repeatedly moves slightly or in small increments at a constant cycle relative to the seal ring 8, thereby reducing friction on the sliding surfaces between the valve element 5 and the seal ring 8. This increases the movement speed of the valve element 5 compared to normal control, thereby improving the operational responsiveness of the solenoid valve 1. In this case, even in a predetermined low-temperature environment, the time required for the valve element 5 to reach the fully closed position (FIG. 1A) to the fully open position (FIG. 1B) is shorter than under normal control, and the time required for the boost pressure P2 to be released is also shorter, thereby preventing surging of the turbocharger 14.

[0039] 5 is a flowchart showing an example of processing executed by the controller 30 in accordance with a program stored in advance in memory. The processing shown in this flowchart is started, for example, when power is supplied to the controller 30, and is repeated at predetermined time intervals.

[0040] First, in step S1, it is determined whether an operation command for the solenoid valve 1 has been input. If the result in step S1 is negative, the process proceeds to step S2, where the process ends without energizing the solenoid valve 1. If the result in step S1 is positive, the process proceeds to step S3, where it is determined whether the engine water temperature TW detected by the water temperature sensor 19 exceeds a predetermined water temperature TW0. If the result in step S3 is positive, the process proceeds to step S4, where it is determined whether a predetermined time has elapsed since the engine water temperature TW reached the predetermined water temperature TW0.

[0041] If the result in step S4 is affirmative, it is determined that the solenoid valve 1 is not in a predetermined low-temperature environment, and the process proceeds to step S5, where the solenoid valve 1 is controlled by normal control so that a current flows continuously through the solenoid valve 1, and the process ends. On the other hand, if the result in step S3 or S4 is negative, it is determined that the solenoid valve 1 is in a predetermined low-temperature environment, and the process proceeds to step S6, where the solenoid valve 1 is controlled by PWM control so that a current flows intermittently through the solenoid valve 1, and the process ends.

[0042] When the solenoid valve 1 is not in a predetermined low temperature environment, such as after the engine 11 has warmed up, the solenoid valve 1 is continuously energized by normal control (steps S1 to S5), which allows the solenoid valve 1 to open early and release the boost pressure P2 (times t1 to t3 in FIG. 4). When the solenoid valve 1 is in a predetermined low temperature environment, such as immediately after the engine 11 has started, the solenoid valve 1 is intermittently energized by PWM control (steps S1 to S4, S6), which allows the solenoid valve 1 to open earlier than in the case of normal control and release the boost pressure P2 (times t1 to t4 in FIG. 4).

[0043] According to the embodiment of the present invention, the following advantageous effects can be achieved. (1) The device 100 controls the opening and closing of the solenoid valve 1, which has an electromagnet (a fixed core 2 and a coil 3) and a valve element 5 that moves relative to the electromagnet due to electromagnetic force. The device 100 includes a water temperature sensor 19 that detects the temperature of the solenoid valve 1, a temperature determination unit 31, and an energization control unit 32 (FIGS. 1A, 1B, and 3).

[0044] When moving the valve element 5, the current control unit 32 uses PWM control to intermittently pass current through the solenoid valve 1 if the temperature detected by the water temperature sensor 19 and the temperature determination unit 31 is equal to or lower than a predetermined temperature, i.e., if the environment is in a predetermined low temperature environment. On the other hand, if the temperature detected by the water temperature sensor 19 and the temperature determination unit 31 is higher than the predetermined temperature, i.e., if the environment is not in a predetermined low temperature environment, the current control unit 32 controls the solenoid valve 1 to pass current continuously through the solenoid valve 1.

[0045] In this way, by energizing using PWM control and moving the valve body 5 in small increments relative to the seal ring 8, the operational response of the solenoid valve 1 can be improved even when friction increases due to contact and sliding between the valve body 5 and the seal ring 8 in a low-temperature environment.

[0046] (2) The solenoid valve 1 is provided in a flow path 10 that connects the upstream and downstream sides of a compressor 14b in an intake passage 12 of an engine 11 having a turbocharger 14, and closes the flow path 10 when de-energized and opens the flow path 10 when energized (Figs. 1A, 1B, and 2). By improving the operational responsiveness of the solenoid valve 1 that is responsible for releasing the supercharging pressure P2, it is possible to ensure the timely release of the supercharging pressure P2, prevent surging of the supercharger 14, and improve the durability, reliability, and acoustic quality of the engine 11.

[0047] (3) The solenoid valve 1 is provided in a flow path 10 that connects the upstream and downstream sides of a compressor 14b in an intake passage 12 of an engine 11 having a turbocharger 14, and closes the flow path 10 when not energized and opens the flow path 10 when energized (FIGS. 1A, 1B, and 2). The water temperature sensor 19 and the temperature determination unit 31 detect the temperature of the solenoid valve 1 based on the engine water temperature TW. When moving the valve element 5, the energization control unit 32 controls the solenoid valve 1 to continuously supply current to the solenoid valve 1 on the condition that a predetermined time has elapsed after the engine water temperature TW has reached a predetermined water temperature TW0 (steps S1 to S5 in FIG. 5).

[0048] The temperature of the solenoid valve 1 is detected by detecting the engine water temperature TW, which represents the temperature of the solenoid valve 1, and estimating whether the temperature of the solenoid valve 1 is low or not based on the detected engine water temperature TW, without providing a temperature sensor to the solenoid valve 1, thereby simplifying the configuration of the solenoid valve 1. Furthermore, even when the engine water temperature TW is used as a physical value representing the temperature of the solenoid valve 1, the operational responsiveness of the solenoid valve 1 can be reliably improved by continuing to energize by PWM control until a predetermined time has elapsed after the engine water temperature TW reaches a predetermined water temperature TW0.

[0049] (4) The device 100 is provided in the intake passage 12 of the engine 11 and controls the opening and closing of a solenoid valve 1 having an electromagnet (a fixed core 2 and a coil 3) and a valve element 5 that moves relative to the electromagnet due to electromagnetic force. The device 100 includes a water temperature sensor 19 that detects the temperature (engine water temperature) TW of the coolant that cools the engine 11, and an energization control unit 32 (FIGS. 1A to 3). When moving the valve element 5, the energization control unit 32 applies current intermittently to the solenoid valve 1 by PWM control if the engine water temperature TW detected by the water temperature sensor 19 is equal to or lower than a predetermined water temperature TW0, i.e., if the engine is not in a predetermined low-temperature environment. On the other hand, the energization control unit 32 controls the solenoid valve 1 so that current flows continuously to the solenoid valve 1 if the engine water temperature TW detected by the water temperature sensor 19 is higher than the predetermined water temperature TW0, i.e., if the engine is not in a predetermined low-temperature environment. In this way, by energizing using PWM control and moving the valve body 5 in small increments relative to the seal ring 8, the operational response of the solenoid valve 1 can be improved even when friction increases due to contact and sliding between the valve body 5 and the seal ring 8 in a low-temperature environment.

[0050] (5) The solenoid valve 1 has a spring 6 that biases the valve element 5 in a direction opposite to the direction of movement caused by the electromagnetic force of the electromagnet (fixed core 2 and coil 3), a housing 7 that houses the electromagnet and spring 6 and has an opening 7a through which the valve element 5 is inserted and removed, and a seal ring 8 that seals the gap between the housing 7 and the valve element 5 (FIGS. 1A and 1B). The valve element 5 has a communication hole 5a that communicates between an internal space SP1 of the housing 7 and an external space SP2. The seal ring 8 has a recess 8a that faces the internal space SP1.

[0051] If the pressure in the external space SP2, which communicates with the internal space SP1, is high when the solenoid valve 1 is closed, the high-pressure fluid flowing in through the communication hole 5a pushes and expands the recess 8a of the seal ring 8, resulting in tight contact with the housing 7 and the valve element 5. This improves the sealing performance of the solenoid valve 1 when it is closed, but reduces the operational response when it is opened from the closed state. By energizing using PWM control and moving the valve element 5 in small increments relative to the seal ring 8, the operational response of the solenoid valve 1 can be improved even when friction due to contact and sliding between the valve element 5 and the seal ring 8 increases.

[0052] (6) The seal ring 8 is made of a resin material and is formed in a U-shape or a V-shape (Figs. 1A and 1B). By energizing using PWM control and moving the valve element 5 in small increments relative to the seal ring 8, the operational response of the solenoid valve 1 can be improved even in low-temperature environments where the flexibility of the resin material decreases and friction due to contact and sliding between the valve element 5 and the seal ring 8 increases.

[0053] The above embodiment can be modified in various ways. Modifications will be described below. In the above embodiment, a normally closed solenoid valve 1 has been illustrated in FIGS. 1A and 1B, but the solenoid valve to which the solenoid valve control device is applied is not limited to this. The solenoid valve control device may also be applied to a normally open solenoid valve. The solenoid valve 1 has been illustrated as having a holder 9 that holds the seal ring 8, but the solenoid valve control device may be applied to a solenoid valve that does not have a holder 9, for example, a solenoid valve configured to hold the seal ring 8 by providing a recess in the inner wall of the housing 7. The solenoid valve 1 has been illustrated as having a seal ring 8 that seals the gap between the housing 7 and the valve body 5, but the solenoid valve control device may also be applied to a solenoid valve that does not have a sealing member such as a seal ring. Other specific configurations of the solenoid valve 1 have been illustrated, but the configuration of the solenoid valve is not limited to these. The solenoid valve control device can be suitably applied to all solenoid valves in which friction increases when the valve body moves in a certain low-temperature environment.

[0054] 2 and 3, an example has been described in which the water temperature sensor 19 provided in the engine 11 detects the engine water temperature TW, and the temperature determination unit 31 of the controller 30 estimates the temperature of the solenoid valve 1 based on the engine water temperature TW, but the temperature detection unit that detects the temperature of the solenoid valve is not limited to this. The temperature detection unit may obtain a physical value other than the engine water temperature, such as the time after engine start or the intake air temperature, and detect the temperature of the solenoid valve by estimating it based on this, or may be a sensor that is provided in the solenoid valve and detects the temperature of the solenoid valve, or that detects the temperature of the solenoid valve remotely.

[0055] In the above embodiment, an example has been described in FIG. 2 and the like in which the solenoid valve 1 serving as an air bypass valve opens and closes the flow path 10 serving as an air bypass passage connecting the upstream side and downstream side of the compressor 14b in the intake passage 12 of the engine 11 having the turbocharger 14, but the flow path that the solenoid valve opens and closes is not limited to this.

[0056] In the above embodiment, an example has been described in Figure 2 etc. in which the supercharger 14 of the engine 11 to which the solenoid valve 1 is applied is configured as an exhaust turbine supercharger (turbocharger) having a turbine 14a, but the supercharger may also be configured as a mechanical supercharger (supercharger).

[0057] In the above embodiment, an example of applying the solenoid valve 1 and the device 100 to an engine system including an engine 11 constituted by an internal combustion engine is described in Figure 2 and the like, but the solenoid valve and the solenoid valve control device are not limited to this and may also be applied to, for example, a fuel cell system, etc.

[0058] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications, as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0059] 1 solenoid valve, 2 fixed core, 3 coil, 4 movable core, 5 valve body, 5a communication hole, 6 spring, 7 housing, 7a opening, 8 seal ring, 8a recess, 10 flow path, 10a seating surface, 11 engine, 12 intake passage, 13 exhaust passage, 14 turbocharger, 14a turbine, 14b compressor, 18 throttle valve, 19 water temperature sensor, 20 vehicle, 30 controller, 31 temperature determination unit, 32 current control unit, 100 solenoid valve control device (device), SP1 internal space, SP2 external space

Claims

1. A control device for a solenoid valve that controls opening and closing of a solenoid valve having an electromagnet and a valve element that moves relative to the electromagnet by electromagnetic force, a temperature detection unit that detects the temperature of the solenoid valve; a control unit that, when the valve element is moved, if the temperature detected by the temperature detection unit is equal to or lower than a predetermined temperature, applies a power supply voltage to the solenoid valve by PWM control to cause a current to flow intermittently so that the current flowing through the coil and the electromagnetic force increase or decrease, and changes a duty ratio of the PWM control so that an average value of the voltage input to the solenoid valve increases continuously, while controlling the solenoid valve so that a current is continuously flowed to the solenoid valve if the temperature detected by the temperature detection unit is higher than the predetermined temperature.

2. 2. The solenoid valve control device according to claim 1, The solenoid valve is provided in a bypass passage that connects the upstream side and downstream side of a compressor in an intake passage of an engine having a turbocharger, and closes the bypass passage when de-energized, and opens the bypass passage when energized.

3. 2. The solenoid valve control device according to claim 1, the solenoid valve is provided in a bypass passage connecting an upstream side and a downstream side of a compressor in an intake passage of an engine having a turbocharger, and closes the bypass passage when de-energized and opens the bypass passage when energized; the temperature detection unit detects the temperature of the solenoid valve based on a water temperature of cooling water that cools the engine; The control unit controls the solenoid valve so that, when moving the valve body, a current flows continuously through the solenoid valve on the condition that a predetermined time has elapsed after the water temperature reaches a predetermined water temperature.

4. A control device for a solenoid valve that is provided in an intake passage of an engine and controls opening and closing of a solenoid valve having an electromagnet and a valve element that moves relative to the electromagnet by electromagnetic force, comprising: a water temperature detection unit that detects the temperature of cooling water that cools the engine; a control unit that controls the solenoid valve so that, when the valve body is moved, if the water temperature detected by the water temperature detection unit is equal to or lower than a predetermined water temperature, an electric current is passed intermittently to the solenoid valve by PWM control, and if the water temperature detected by the water temperature detection unit is higher than the predetermined water temperature, an electric current is passed continuously to the solenoid valve.

5. 5. The solenoid valve control device according to claim 4, the engine has a supercharger, The solenoid valve is provided in a bypass passage that connects the upstream side and downstream side of the compressor in the intake passage, and closes the bypass passage when de-energized and opens the bypass passage when energized.

6. 5. The solenoid valve control device according to claim 4, The control unit controls the solenoid valve so that, when moving the valve body, a current flows continuously through the solenoid valve on the condition that a predetermined time has elapsed after the water temperature reaches the predetermined water temperature.

7. The solenoid valve control device according to any one of claims 1 to 6, The solenoid valve is a biasing member that biases the valve body in a direction opposite to a direction of movement of the electromagnet due to the electromagnetic force; a housing that houses the electromagnet and the biasing member and has an opening through which the valve body is inserted and removed; a sealing member that seals a gap between the housing and the valve body, a communication hole that communicates the internal space and the external space of the housing is formed in the valve body; 10. A control device for an electromagnetic valve, wherein the sealing member has a recess facing the internal space.

8. 8. The solenoid valve control device according to claim 7, 10. The control device for an electromagnetic valve, wherein the sealing member is made of a resin material and has a U-shape or a V-shape.

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