Valve device and refrigeration cycle device

Abstract

To suppress failure resulting from adhesion of rainwater or dew condensation water.SOLUTION: A valve device according to the embodiment comprises: a valve body having a movable element that operates in conjunction with a valve element part, and a body case in which the movable element is housed; and a coil housing that can insert / remove the valve body, and is configured as a separate body from the valve body, and in which a coil for driving the movable element is housed. The valve body is inserted into the coil housing with the movable element and the coil facing each other, and a surface part of the body case is subjected to hydrophilic treatment, water sliding treatment, or water repellency treatment.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] An embodiment of the present invention relates to a valve device and a refrigeration cycle device. [Background technology]

[0002] There exists a valve device in which the valve body that houses the rotor and the coil housing that houses the coil are each separate components, and the valve body is configured to be insertable into and removable from the coil housing. In such a valve device, a small gap remains between the inner peripheral surface of the coil and the outer peripheral surface of the valve body in the inner diameter portion of the coil where the valve body is placed (hereinafter sometimes referred to as the "main body insertion portion"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-074505 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is assumed that rainwater or condensation water generated by other components will drip onto the valve device, or that water vapor present in the gaps in the main body insertion section will condense and accumulate in the gaps. When the valve device is in operation, the valve body is cooled by a phase change of the refrigerant flowing inside the valve body, and the rainwater or condensation water adhering to the valve device will freeze and eventually block the opening of the main body insertion section, specifically, the opening of the gap remaining in the main body insertion section. In this way, the condensation water accumulated in the gaps is not expelled, and freezing progresses in the gaps, which causes the volume expansion of the water due to freezing to compress the valve body, raising concerns that the valve body may be damaged.

[0005] Furthermore, it is possible that the coil housing will rust due to contact with condensation water accumulated in the gap, which will then cause the valve body to rust. There is also a concern that the valve body and the coil housing will become stuck together due to the rust, making it impossible to remove the valve body from the coil housing and replace it in the event of a malfunction.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to provide a valve device and a refrigeration cycle device that suppress problems caused by the adhesion of rainwater or condensation water. [Means for solving the problem]

[0007] The valve device according to the embodiment of the present invention includes a movable element that operates in conjunction with a valve body portion and a main body case that houses the movable element. The surface of the main body case is treated to be hydrophilic, water-slippery or water-repellent. a valve body that drives the rotor; and a coil housing that is configured as a separate body from the valve body so that the valve body can be inserted and removed, and that houses a coil that drives the rotor. a control unit configured to be able to apply a drive current to the coil for controlling the valve body portion to a target position; The valve body is inserted into the coil housing with the armature and the coil facing each other, The control unit applies a current to the coil by adding a predetermined vibration pattern current for moving the valve body toward and away from the target position to a drive current corresponding to the target position. .

[0008] A refrigeration cycle apparatus according to an embodiment of the present invention includes a valve device, a compressor, a first heat exchanger configured to be able to exchange heat between a fluid to be adjusted and a refrigerant, a second heat exchanger configured to be able to exchange heat between outside air and the refrigerant, and a refrigerant pipe that connects the compressor, the first heat exchanger, and the second heat exchanger and circulates the refrigerant between the compressor, the first heat exchanger, and the second heat exchanger. The valve device is installed in the refrigerant pipe and switches the flow path of the refrigerant in the refrigerant pipe or the opening area of ​​the flow path. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an overall configuration of a refrigeration cycle device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a front view showing the appearance of a valve device provided in the refrigeration cycle apparatus. [Diagram 3] FIG. 2 is a cross-sectional view showing the internal configuration of a valve body that constitutes the valve device. [Figure 4]FIG. 4 is a cross-sectional view showing an internal configuration of a coil housing that constitutes the valve device. [Diagram 5] 4 is a flowchart showing an example of an operation of the valve device. [Figure 6] 4 is an explanatory diagram showing an example of a vibration pulse pattern generated during opening control of the valve device. FIG. [Figure 7] 4 is an explanatory diagram showing an example of a vibration pulse pattern generated when the valve device is fully closed; FIG. [Figure 8] 4 is an explanatory diagram showing an example of a vibration pulse pattern generated when the valve device is fully opened; FIG. [Figure 9] 1A and 1B are a front view and a cross-sectional view of a coil housing, respectively, showing an example of an application of a valve device according to an embodiment of the present invention to a four-way valve. [Figure 10] 1A and 1B are a front view and a cross-sectional view of a coil housing, respectively, showing an example of an application of a valve device according to an embodiment of the present invention to a two-way valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a schematic diagram showing an overall configuration of a refrigeration cycle apparatus RC according to an embodiment of the present invention.

[0012] In this embodiment, the refrigeration cycle device RC constitutes an air conditioner (also called an "air conditioner" or "air handling unit"). The refrigeration cycle device RC can adjust the temperature inside the room. In FIG. 1, the flow of the refrigerant during cooling is indicated by solid arrows, and the flow of the refrigerant during heating is indicated by dotted arrows. In this embodiment, a mixed refrigerant containing trifluoroiodomethane (expressed as "CF3I") is used as the refrigerant.

[0013] The refrigeration cycle apparatus RC of this embodiment includes, as its main components, a compressor 1, an outdoor heat exchanger 2, an indoor heat exchanger 3, a four-way valve 4, an expansion valve 5, and a two-way valve 6, as well as refrigerant piping 7 that fluidly connects these components and circulates refrigerant between these components.

[0014] The compressor 1 compresses the refrigerant, increases its pressure, and discharges it. The compressor 1 can change its operating frequency by known inverter control. The operating frequency does not necessarily need to be changeable, and the compressor may have a constant operating frequency.

[0015] The outdoor heat exchanger 2 is installed outdoors and exchanges heat between outdoor air and a refrigerant. The outdoor heat exchanger 2 is housed in a case of the outdoor unit OU together with an outdoor blower (not shown) as a component of the outdoor unit OU. FIG. 1 conceptually shows the area housed in the case of the outdoor unit by a two-dot chain line. An example of a heat exchanger that can be applied to the outdoor heat exchanger 2 is a fin-and-tube type heat exchanger. The outdoor heat exchanger 2 corresponds to the "second heat exchanger" according to this embodiment.

[0016] The indoor heat exchanger 3 is installed indoors and exchanges heat between the fluid to be adjusted and the refrigerant. The indoor heat exchanger 3 is housed in a case of the indoor unit together with an indoor blower (not shown) as a component of the indoor unit. As with the outdoor heat exchanger, a fin-and-tube type heat exchanger can be exemplified as an applicable component for the indoor heat exchanger 3. In this embodiment, the fluid to be adjusted is indoor air. The indoor heat exchanger 3 corresponds to the "first heat exchanger" in this embodiment.

[0017] The four-way valve 4 switches the flow path of the refrigerant discharged by the compressor 1 between cooling and heating. During cooling, the four-way valve 4 sets the refrigerant flow path in a direction from the four-way valve 4 to the outdoor heat exchanger 2. As a result, the refrigerant leaving the four-way valve 4 passes through the outdoor heat exchanger 2 and then flows into the indoor heat exchanger 3. In contrast, during heating, the refrigerant flow path is switched to a direction from the four-way valve 4 to the indoor heat exchanger 3. As a result, the refrigerant leaving the four-way valve 4 passes through the indoor heat exchanger 3 and then flows into the outdoor heat exchanger 2.

[0018] The expansion valve 5 adjusts the pressure of the refrigerant leaving the condenser (specifically, the outdoor or indoor heat exchanger 2, 3 functioning as a condenser) by the action of an orifice, and adjusts the pressure of the refrigerant heading toward the evaporator (specifically, the indoor or outdoor heat exchanger 3, 2 functioning as an evaporator) by causing a pressure drop due to flow resistance.

[0019] The two-way valve 6 controls the flow rate of the refrigerant flowing through the refrigerant piping. In this embodiment, a liquid injection cooling method is adopted, and the two-way valve 6 has a function of controlling the flow rate of the refrigerant in an injection circuit that introduces a portion of the refrigerant that has left the condenser into the compressor 1, according to the discharge temperature of the refrigerant from the compressor 1. In this embodiment, the two-way valve 6 operates as an opening / closing valve that switches between opening and closing the flow path.

[0020] The refrigerant piping 7 fluidly connects the compressor 1, the outdoor heat exchanger 2, the indoor heat exchanger 3, the four-way valve 4, the expansion valve 5, and the two-way valve 6. In this embodiment, the refrigerant piping 7 is roughly divided into a first refrigerant pipe 7a connected to the compressor 1 and the four-way valve 4, a second refrigerant pipe 7b connected to the four-way valve 4 and the outdoor heat exchanger 2, a third refrigerant pipe 7c connected to the outdoor heat exchanger 2 and the expansion valve 5, a fourth refrigerant pipe 7d connected to the expansion valve 5 and the indoor heat exchanger 3, a fifth refrigerant pipe 7e connected to the indoor heat exchanger 3 and the four-way valve 4, a sixth refrigerant pipe 7f connected to the four-way valve 4 and the compressor 1, a seventh refrigerant pipe 7g branching from the third refrigerant pipe 7c and connecting the two-way valve 6 to the third refrigerant pipe 7c, and an eighth refrigerant pipe 7h connected to the two-way valve 6 and the compressor 1. The seventh refrigerant pipe 7g and the eighth refrigerant pipe 7h constitute an injection circuit, and fluidly connect the condenser and the compressor 1, bypassing the evaporator.

[0021] During cooling, the four-way valve 4 connects the inlet 4a to the first outlet 4b and the second outlet 4c to the outlet 4d. The flow path of the four-way valve 4 is switched by controlling a pilot valve. During cooling, the outdoor heat exchanger 2 operates as a condenser or a radiator, and the indoor heat exchanger 3 operates as an evaporator or a heat absorber. The refrigerant discharged from the compressor 1 flows through the four-way valve 4 to the outdoor heat exchanger 2, and after being acted upon by the expansion valve 5 and the two-way valve 6, passes through the indoor heat exchanger 3, and then returns to the compressor 1 through the four-way valve 4. A part of the refrigerant that has left the outdoor heat exchanger 2 flows into the seventh refrigerant pipe 7g depending on the situation, and is introduced into the compressor 1 through the two-way valve 6.

[0022] On the other hand, during heating, the four-way valve 4 switches the connection destination of the inlet 4a to the second inlet 4c and the connection destination of the outlet 4d to the first inlet 4b under the control of the pilot valve. During heating, the indoor heat exchanger 3 operates as a condenser or a radiator, and the outdoor heat exchanger 2 operates as an evaporator or a heat absorber. The refrigerant discharged from the compressor 1 flows through the four-way valve 4 to the indoor heat exchanger 3, and after being acted upon by the two-way valve 6 and the expansion valve 5, passes through the outdoor heat exchanger 2, and further returns to the compressor 1 through the four-way valve 4. After the refrigerant leaves the indoor heat exchanger 3, it passes through the expansion valve 5, and part of it flows into the seventh refrigerant pipe 7g depending on the situation, and is introduced into the compressor 1 through the two-way valve 6.

[0023] FIG. 2 is a front view showing the appearance of the valve device 5 provided in the refrigeration cycle apparatus according to this embodiment, and shows a state in which the valve body 51 and the coil housing 52 are combined together when the valve device 5 is in use or in operation. FIG. 3 is a cross-sectional view showing the internal configuration of the valve body 51, and FIG. 4 is a cross-sectional view showing the internal configuration of the coil housing 2. FIG. 4 also shows a control unit 101 that controls the operation of the valve device 5. The configuration of the valve device 5 according to this embodiment will be described with appropriate reference to FIGS. 2 to 4. In this embodiment, the valve device is applied to an expansion valve 5 provided in a refrigeration cycle apparatus.

[0024] In the expansion valve 5, the valve body 51 and the coil housing 52 are each configured as a separate unit. As shown in Fig. 2, the valve body 51 and the coil housing 52 are aligned coaxially with each other when in use. In this embodiment, the expansion valve 5 is a direct-acting electronic expansion valve that uses a stepping motor. In other words, the expansion valve 5 operates using the stepping motor as a drive source or actuator.

[0025] As shown in FIG. 3, the valve body 51 constitutes a so-called needle valve and includes a valve body portion 511 and a rotor 512 connected to the valve body portion 511 so as to be movable forward and backward. An appropriate motion conversion mechanism such as a lead screw (also called a "sliding screw") 513 is installed between the valve body portion 511 and the rotor 512. When the rotor 512 rotates, the rotational motion is converted into linear motion via the motion conversion mechanism and transmitted to the valve body portion 511. As a result, the valve body portion 511 moves a distance according to the rotation angle of the rotor 512. Depending on the amount of movement of the valve body portion 511, a tip end (hereinafter referred to as "tip end") 511a of the valve body portion 511 repeatedly seats on and leaves a valve seat portion 514, and the opening between the valve body portion 511 and the valve seat portion 514, i.e., the opening area of ​​the orifice, changes. In the valve body 51, the motion conversion mechanism including the rotor 512 and the lead screw 513 is airtightly housed in a cylindrical body case 515 also called a "can." The rotor 512 corresponds to the "movable element" in this embodiment.

[0026] As shown in FIG. 4, the coil housing 52 includes a coil 521 of a predetermined number of phases, and a housing portion 522 configured to accommodate the coil 521. The housing portion 522 is provided with a main body insertion portion 522a that is coaxial with the coil 521 and is integrated with the inner diameter portion of the coil 521 to form a continuous cylindrical space. The main body insertion portion 522a is capable of receiving the main body case 515 of the valve main body 51. In other words, the main body insertion portion 522a has an inner diameter that is approximately equal to the outer diameter of the main body case 515, and has a depth that is equal to the length of at least the portion of the main body case 515 in which the rotor 512 is accommodated. With the main body case 515 inserted into the main body insertion portion 522a, the inner peripheral surface of the coil 521 and the outer peripheral surface of the rotor 512 face each other across the cylindrical side portion 515a of the main body case 515. The main body insertion portion 522a is not only for inserting the valve main body 51, but also for removing it for replacing parts when the expansion valve 5 breaks down. The coil housing 52 includes a connector portion 523 for supplying power to the coils 521 of each phase and for communicating with external devices.

[0027] The expansion valve 5 is driven by a stepping motor composed of a rotor 512 and a coil 521, and its opening is controlled by the controller 111 and the motor driver 112. The controller 111 sets a target opening of the expansion valve 5 based on predetermined input information, and outputs a clock pulse signal with a pulse number corresponding to the target opening. The motor driver 112 receives the clock pulse signal output by the controller 111, and outputs a drive current for controlling the expansion valve 5 to the target opening, in other words, for controlling the valve body portion 511 to a position corresponding to the pulse number P of the clock pulse signal. Then, the drive current is supplied to the coil 521, so that the rotor 512 rotates, the valve body portion 511 moves, and the orifice opens or closes. In this embodiment, an outside air temperature sensor 113 for detecting an outside air temperature Tatm is provided, and a surface temperature sensor 114 for detecting a surface temperature Tbsf of the main body case 515 (hereinafter referred to as "main body surface temperature") is provided. Temperature information detected by the outside air temperature sensor 113 and the surface temperature sensor 114 is input to the controller 111. The controller 111 and the motor driver 112 constitute a "control unit" according to this embodiment.

[0028] In this embodiment, the controller 111 sets the pulse number P of the clock pulse signal between 0 and 500. The valve body 511 is biased in the closing direction against the main body case 515 by the compression coil spring 516, and when the pulse number P set by the controller 111 is 0, the valve body 511 is seated on the valve seat 514, and the expansion valve 5 is in a fully closed state. That is, in this embodiment, the expansion valve 5 is a normally closed valve. In contrast, when the pulse number P set by the controller 111 is 500, the valve body 511 moves to a position farthest from the valve seat 514, and the expansion valve 5 is in a fully open state. The expansion valve 5 can be controlled to an intermediate opening degree by appropriately changing the pulse number P of the clock pulse signal between 0 and 500.

[0029] Here, the main body case 515 of the valve main body 51 is subjected to a surface treatment of either hydrophilicity, water slippage or water repellency. In this embodiment, the surface of the main body case 515 that faces the inner peripheral surface of the coil 521 when the valve main body 51 is inserted into the main body insertion part 522a of the coil housing 52, specifically, the outer peripheral surface of the cylindrical side part 515a, is subjected to a coating of either hydrophilicity, water slippage or water repellency (hereinafter referred to as "frost-resistant coating") as the surface treatment of the main body case 515. The main body case 515 is formed from stainless steel. The outer peripheral surface of the cylindrical side part 515a corresponds to the "surface part" of the main body case according to this embodiment.

[0030] In this embodiment, the application of a "hydrophilic" frost-resistant coating adjusts the wetting angle of water to, for example, about 30°. On the other hand, the application of a "water-slippery" frost-resistant coating adjusts the wetting angle of water to, for example, about 50° to 80°, and the application of a "water-repellent" frost-resistant coating adjusts the wetting angle of water to, for example, about 95° to 105°.

[0031] "Water slippage" refers to the ease with which water or water droplets adhering to a solid surface slide off, and is generally evaluated by the magnitude of the inclination angle of the solid surface when a water droplet starts to fall from the solid surface. From the viewpoint of the difficulty of water fitting to a solid surface, water slippage or water slippage can also be rephrased as hydrophobicity or hydrophobicity.

[0032] During operation of the refrigeration cycle device RC, rainwater that has entered the outdoor unit OU or condensation water generated by other components housed in the outdoor unit OU may drip and adhere to the expansion valve 5, or water vapor present in the gap remaining between the inner circumferential surface of the coil 521 and the surface of the main body case 515 inside the coil housing 52 may condense and accumulate in the gap. In the expansion valve 5, a phase change occurs due to adiabatic expansion when the refrigerant passes through the orifice, and the valve body 51 is cooled in the area around the orifice due to the heat absorption effect associated with this, and the temperature drops locally. Here, a problem with the conventional technology is that if rainwater or condensation water remains attached to the main body case 515, the water freezes and eventually blocks the opening of the main body insertion part 522a, that is, the opening of the gap remaining between the inner circumferential surface of the coil 521 and the surface of the main body case 515. In this way, the condensed water that has accumulated in the gap is not expelled, and as freezing progresses within the gap, the volume of the water expands due to freezing, compressing the valve body 51, causing dents or cracks in the valve body 51, particularly the main body case 515, which may interfere with the operation of the rotor 512 and lead to failure.

[0033] Furthermore, if rust occurs on coil housing 52 due to contact with condensed water accumulated in the gap, this rust will cause rust to form on main body case 515, particularly cylindrical side surface portion 515a. If the valve body 51 and coil housing 52 become stuck together due to the rust, there is a risk that it will become impossible to remove valve body 51 from coil housing 52 and replace it in the event of a malfunction, etc.

[0034] In contrast, in this embodiment, a predetermined frost-resistant coating is applied to the outer peripheral surface of the cylindrical side portion 515a of the main body case 515 facing the inner peripheral surface of the coil 521, to encourage rainwater or condensation water adhering to the valve body 51, particularly the main body case 515, to fall from the main body case 515, so that the rainwater or the like does not remain on the surface of the main body case 515. In addition, in this embodiment, a predetermined operating current is added to the drive current of the coil 521 according to the target opening of the expansion valve 5, and a current is supplied to the coil 521 in a superimposed manner within a range that does not significantly affect the flow control itself by the expansion valve 5. Specifically, a vibration pattern current according to a predetermined vibration pulse pattern is added to the drive current, causing the valve body portion 511 to vibrate in small increments, or generating heat by energizing the coil 521.

[0035] FIG. 5 is a flowchart showing an example of processing executed by the controller 111 according to this embodiment.

[0036] In S101, it is determined whether or not to perform the dew condensation countermeasure operation. The dew condensation countermeasure operation is performed, for example, at predetermined time intervals after the operation of the refrigeration cycle apparatus RC is started. If the dew condensation countermeasure operation is performed, the process proceeds to S102, and if not, the control according to this routine is terminated.

[0037] In S102, the outside air temperature Tatm is read. The outside air temperature Tatm is detected by the outside air temperature sensor 113. The outside air temperature Tatm is an index of the ambient temperature of the valve device, and the outside air temperature sensor 113 is an example of an "ambient temperature detection unit."

[0038] In S103, the body surface temperature Tbsf is read. The body surface temperature Tbsf is detected by the surface temperature sensor 114. The body surface temperature Tbsf is an index of the temperature of the surface portion of the body case, and the surface temperature sensor 114 is an example of a "surface temperature detection portion."

[0039] In S104, the dew-point temperature Tdwp is calculated. The dew-point temperature Tdwp can be calculated in a simple manner based on the outside air temperature Tatm.

[0040] In S105, it is determined whether the body surface temperature Tbsf is equal to or lower than the dew-point temperature Tdwp, in other words, whether or not there is a possibility of water condensing on the surface of the body case 515. If the body surface temperature Tbsf is equal to or lower than the dew-point temperature Tdwp, it is determined that there is a possibility of condensation and the process proceeds to S106, and if the body surface temperature Tbsf is higher than the dew-point temperature Tdwp, the control according to this routine is terminated.

[0041] In S106, a predetermined vibration pulse pattern is added to the clock pulse signal, and the clock pulse signal after the vibration pulse pattern is added is output. As a result, a current component according to the vibration pulse pattern, i.e., a vibration pattern current, is supplied to the coil 521, and the valve body 511 moves by a step according to the pulse number dltP of the vibration pulse pattern to a position according to the target opening.

[0042] FIG. 6 is an explanatory diagram showing an example of a vibration pulse pattern.

[0043] In this embodiment, a predetermined forward pulse number dltP1 and a predetermined backward pulse number -dltP2 are alternately added to the pulse number Pd corresponding to the target opening of the expansion valve 5. The forward pulse number dltP1 and the backward pulse number -dltP2 may have the same absolute value (dltP1=|-dltP2|) or may be different. The valve body 511 moves in the opening direction from the position corresponding to the target opening, that is, moves backward, by adding the forward pulse number dltP1, and moves in the closing direction from the position corresponding to the target opening, that is, moves forward, by adding the backward pulse number -dltP2. The expansion valve 5 repeats forward and backward movements within a range that does not greatly affect the flow control itself by adding the vibration pulse pattern, in other words, by adding the forward pulse number dltP1 and the backward pulse number -dltP2.

[0044] In this way, the vibration pulse pattern can be added during the opening control of the expansion valve 5, that is, when the expansion valve 5 is at an intermediate opening. The addition of the vibration pulse pattern is not limited to this, and can also be performed at a timing other than during the opening control.

[0045] FIG. 7 shows, as another example of the vibration pulse pattern, a vibration pulse pattern that is applied when the expansion valve 5 is fully closed.

[0046] In the example shown in FIG. 7, the pulse number P of the clock pulse signal is decreased by a predetermined number of pulses per unit time from the pulse number at the fully closed state (hereinafter referred to as the "fully closed pulse number") Pmin (time t11). The valve body portion 511 is further pushed from the fully closed position toward the valve seat portion 514 by adding (i.e., subtracting) a predetermined number of pulses. In this embodiment, the fully closed pulse number Pmin is set to 0, and subtracting the number of pulses from the fully closed pulse number Pmin generates an adhesive force in the reverse direction on the rotor 512. Thereafter, at the timing when the clock pulse signal reaches the limit valve close pulse number Plim1 (time t12), the pulse number P of the clock pulse signal is increased by the cumulative value of the subtracted pulse number, and is returned to the fully closed pulse number Pmin (time t13). With the return to the fully closed pulse number Pmin, the valve body portion 511 is pushed back toward the fully closed position, and the inertia acting on the valve body portion 511 causes the valve body 51 to swing or vibrate. After that, the pulse number P is repeatedly increased to the limit valve-close pulse number Pmin1 and returned to the full-close pulse number Pmin a predetermined number of times. Fig. 7 shows an example of a case where, after time t11 when the addition of the vibration pulse pattern starts, the pulse number P is reduced from the full-close pulse number Pmin by one pulse per unit time, and is returned to the full-close pulse number Pmin at the timing when the cumulative subtraction value of the pulse number P reaches 8.

[0047] FIG. 8 shows, as yet another example of a vibration pulse pattern, a vibration pattern that is applied when the expansion valve 5 is fully open.

[0048] In the example shown in FIG. 8, the pulse number P of the crop pulse signal is increased by a predetermined number of pulses per unit time from the pulse number at the fully open state (hereinafter referred to as the "fully open pulse number") Pmax (time t21). The valve body 511 moves further from the fully open position, that is, moves backward, by adding (i.e., adding) the predetermined number of pulses, and hits the opening direction stopper portion 515b of the main body case 515 at the timing when the clock pulse signal reaches the limit valve open pulse number Plim2 (time t22). FIG. 3 shows the opening direction stopper portion 515b arranged on the upper cover portion of the main body case 515 so as to face the rear end edge of the valve body portion 511, and the opening direction stopper portion 515b restricts the movement of the valve body portion 511 in the opening direction beyond the fully open position. Thereafter, the pulse number P of the clock pulse signal is decreased by the cumulative value of the added pulse number, and returned to the fully open pulse number Pmax (time t23). As the number of full-open pulses Pmax returns to the full-open position, the valve body 511 is pushed back by the opening direction stopper 515b toward the full-open position, and the inertia acting on the valve body 511 causes the valve body 51 to sway or vibrate. After that, the number of pulses P is repeatedly reduced to the limit number of valve-open pulses Plim2 and returned to the number of full-open pulses Pmax a predetermined number of times. Fig. 8 shows an example of a case where, after time t21 when the addition of the vibration pulse pattern starts, the number of pulses P is increased by one pulse per unit time from the number of full-open pulses Pmax, and is returned to the number of full-open pulses Pmax at the timing when the cumulative added value of the number of pulses P reaches 8.

[0049] The refrigeration cycle apparatus RC and the valve device (that is, the expansion valve) 5 according to this embodiment have the above-mentioned configurations. The effects obtained by this embodiment will be described below.

[0050] First, by subjecting the surface of main body case 515 to a hydrophilic, water-slippery, or water-repellent treatment, when water such as rainwater or condensation adheres to valve main body 51, it is possible to prevent the water from dropping from the surface and remaining on the surface of main body case 515. This makes it possible to prevent the adhered water from freezing on the surface of main body case 515 and blocking the opening of the gap remaining between valve main body 51 and coil housing 52, specifically, the gap remaining between the inner circumferential surface of coil 521 and the surface of main body case 515.

[0051] This ensures that condensation water generated in the gap between the valve body 51 and the coil housing 52 has an opportunity to be discharged from this gap, thereby making it possible to prevent freezing from progressing in the gap and causing damage to the valve body 51.

[0052] Furthermore, it is possible to avoid prolonged contact between the coil housing 52 and water, thereby preventing rust from forming on the coil housing 52 and causing the valve body 51 and the coil housing 52 to stick to each other due to this rust.

[0053] The surface treatment applied to main body case 515 can be carried out relatively easily by forming a hydrophilic, water-slippery or water-repellent coating.

[0054] Secondly, the application of the vibration pattern current makes it possible to heat the coil 521 and heat the surface of the valve body 51, particularly the main body case 515. This suppresses the occurrence of condensation itself, promotes the evaporation of water adhering to the surface, and more actively suppresses defects caused by the adhesion of water. The current added to the drive current, that is, the operation current, is not limited to the vibration pattern current described above, and may be increased by the number of pulses that suppresses the adhesive force of the coil 521 to a range that does not actually move the valve body 511 when fully closed, or may be increased by the number of pulses that suppresses the ambient temperature of the coil 521 and the rotor 512 and the temperature of the coil winding to a permissible range when fully open.

[0055] Thirdly, by detecting the temperature of the surface of main body case 515 and adding a vibration pattern current when this is below the dew point temperature of water, it is possible to eliminate unnecessary addition of a vibration pattern current and more efficiently achieve the effect of promoting evaporation of water adhering to the surface.

[0056] Fourthly, when the valve body 511 is in the fully closed position, an operation of decreasing the pulse number P of the clock pulse signal from the fully closed pulse number Pmin and an operation of canceling the subtraction of the pulse number P are alternately performed on the coil 521, so that water adhering to the surface of the main body case 515 can be shaken off by vibration (based on the inertia of the valve body 511) that occurs when the subtraction of the pulse number P is canceled. This makes it possible to more actively remove the adhering water from the surface. The operation of decreasing the pulse number P of the clock pulse signal from the fully closed pulse number Pmin corresponds to the operation of adding the "first superimposed current" according to this embodiment.

[0057] Fifth, when the valve body 511 is in the fully open position, the operation of increasing the pulse number P of the clock pulse signal from the fully open pulse number Pmax and the operation of canceling the addition of the pulse number P are alternately performed on the coil 521, so that water adhering to the surface of the main body case 515 can be shaken off by the vibration (based on the inertia of the valve body 511) that occurs when the addition of the pulse number P is canceled. This makes it possible to more actively remove the adhering water from the surface. The operation of increasing the pulse number P of the clock pulse signal from the fully open pulse number Pmax corresponds to the operation of adding the "second superimposed current" according to this embodiment.

[0058] In the above description, the expansion valve 5 is used as the valve device. However, the applicable objects of the valve device are not limited to this, and examples of the valve device include various valve devices such as a four-way valve 4 or a two-way valve 6 in addition to the expansion valve.

[0059] FIG. 9 shows an example in which a four-way valve 4 is used as a valve device according to another embodiment of the present invention, with (a) being a front view of a valve body 41 and (b) being a cross-sectional view of a coil housing .

[0060] In this embodiment, the valve body 41 of the four-way valve 4 includes a pilot valve 411, and the valve body 41 and the coil housing 42 are configured separately as individual components. As in the first embodiment, the pilot valve 411 houses a moving element, for example, a rotor, which operates in conjunction with the valve body, and the coil housing 42 houses a coil 421 that drives the moving element. The pilot valve 411 is removably attached to the coil housing 42, and when attached to the coil housing 42, the moving element housed in the main body case (also called "can") 412 of the pilot valve 411 and the coil 421 housed in the coil housing 42 face each other. Of the pilot valve 411, the surface portion of the main body case 412, specifically, the outer periphery facing the inner periphery of the coil 421, is subjected to a hydrophilic, water-slippery, or water-repellent surface treatment, for example, a frost-resistant coating.

[0061] FIG. 10 shows an example in which a two-way valve 6 is used as a valve device as yet another embodiment of the present invention, with (a) being a front view of a valve body 61 and (b) being a cross-sectional view of a coil housing 62.

[0062] In this embodiment, the valve body 61 and the coil housing 62 of the two-way valve 6 are configured as separate components. As in the first embodiment, the valve body 61 houses a moving element, for example, a rotor, which operates in conjunction with the valve body, and the coil housing 62 houses a coil 621 that drives the moving element. The valve body 61 is removably attached to the coil housing 62, and when the valve body 61 is attached to the coil housing 62, the moving element housed in the main body case (also called "can") 611 of the valve body 61 and the coil 621 housed in the coil housing 62 face each other. Of the valve body 61, the surface portion of the main body case 611, specifically, the outer periphery facing the inner periphery of the coil 621, is subjected to a hydrophilic, water-slippery, or water-repellent surface treatment, for example, a frost-resistant coating.

[0063] In the above description, a direct-acting electronic expansion valve using a stepping motor is used as the expansion valve 5. The drive system of the expansion valve 5 is not limited to this, and it is also possible to use a gear system in which a suitable speed change mechanism, such as a reduction gear, is provided between the valve body 511 and the rotor 512 while using a stepping motor as the drive source.

[0064] In the above description, the refrigeration cycle apparatus RC is applied to an air conditioner, but the refrigeration cycle apparatus RC can be applied to other devices, such as refrigerators or water heaters, without being limited thereto.

[0065] The refrigeration cycle apparatus RC applied to the refrigerator has a circuit configuration corresponding to the case where cooling is performed in the example shown in Fig. 1. The fluid to be regulated is, for example, the air inside the refrigerator.

[0066] The refrigeration cycle apparatus RC applied to a water heater has a circuit configuration corresponding to the case where heating is performed in the example shown in Fig. 1. The fluid to be regulated is, for example, water or hot water.

[0067] Although several embodiments of the present invention have been described, these embodiments are merely presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0068] RC...refrigeration cycle device, OU...outdoor unit, 1...compressor, 2...outdoor heat exchanger, 3...indoor heat exchanger, 4...four-way valve, 5...expansion valve, 51...valve body, 511...valve body portion, 512...rotor, 513...lead screw, 514...valve seat portion, 515...main body case, 515a...cylindrical side portion, 515b...opening direction stopper portion, 516...compression coil spring, 52...coil housing, 521...coil, 522...housing portion, 522a...main body insertion portion, 523...connector portion, 6...two-way valve, 7...refrigerant piping, 7a to 7h...refrigerant pipe, 101...control portion, 111...controller, 112...motor driver, 113...outdoor air temperature sensor, 114...surface temperature sensor.

Claims

1. a valve body having a moving element that operates in conjunction with a valve body portion and a main body case in which the moving element is housed, the main body case having a surface that has been treated to be hydrophilic, water-slippery or water-repellent; a coil housing configured as a separate body from the valve body so that the valve body can be inserted and removed, the coil housing housing housing containing a coil for driving the rotor; a control unit configured to be able to apply a drive current to the coil to control the valve body portion to a target position, The valve body is inserted into the coil housing with the rotor and the coil facing each other, The control unit adds a predetermined vibration pattern current that moves the valve body portion toward and away from the target position to a drive current corresponding to the target position, and energizes the coil.

2. The valve device according to claim 1 , wherein the surface portion is provided with a hydrophilic, water-slippery or water-repellent coating as the hydrophilic, water-slippery or water-repellent treatment.

3. A valve device as described in claim 1 or 2, wherein the control unit adds the specified vibration pattern current to the drive current and passes current through the coil when the temperature of the surface portion is below the dew point temperature of water.

4. 4. The valve device according to claim 1, wherein when the valve body is in a fully closed position, the control unit alternately performs an operation of adding a first superimposed current that drives the valve body further in a closing direction from the fully closed position and an operation of canceling the application of the first superimposed current as the addition of the predetermined vibration pattern current.

5. 4. The valve device according to claim 1, wherein when the valve body is in a fully open position, the control unit alternately performs an operation of adding a second superimposed current that drives the valve body further in an opening direction from the fully open position and an operation of canceling the application of the second superimposed current as the addition of the predetermined vibration pattern current.

6. A compressor; A first heat exchanger configured to be able to exchange heat between the fluid to be adjusted and a refrigerant; A second heat exchanger configured to be able to exchange heat between outside air and the refrigerant; a refrigerant pipe that connects the compressor, the first heat exchanger, and the second heat exchanger and circulates the refrigerant among the compressor, the first heat exchanger, and the second heat exchanger; A refrigeration cycle apparatus comprising: the valve device according to claim 1 , which is installed in the refrigerant piping and is configured to be able to switch a flow path of the refrigerant in the refrigerant piping or an opening area of ​​the flow path.

7. 7. The refrigeration cycle apparatus according to claim 6, wherein the valve device is provided in a four-way valve configured to be able to switch a flow path of the refrigerant through the refrigerant piping so that a flow direction of the refrigerant between the first heat exchanger and the second heat exchanger is reversed.

8. The refrigeration cycle apparatus according to claim 6, wherein the valve device is provided in a two-way valve configured to be able to adjust a flow rate of the refrigerant in the refrigerant pipe.

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