CN113544085A

CN113544085A - Valve device

Info

Publication number: CN113544085A
Application number: CN202080016790.6A
Authority: CN
Inventors: 河本阳一郎; 押谷洋; 长野阳平; 小川博史; 内田和秀
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2019-02-28
Filing date: 2020-02-26
Publication date: 2021-10-22
Anticipated expiration: 2040-02-26
Also published as: CN113544085B; JP2020143786A; JP7014239B2

Abstract

The valve device is provided with a main body (51), a valve body (52), and a control valve member (Y1), wherein the control valve member (Y1) changes the pressure acting on pressure chambers (51g, 58a), and the pressure chambers (51g, 58a) generate control pressure for moving the valve body (52). The control valve member (Y1) has: a base (Y11, Y121, Y13) formed with a refrigerant chamber (Y19), a first refrigerant hole (Y16) communicating with the refrigerant chamber (Y19) and with the pressure chambers (51g, 58a), and second refrigerant holes (Y17, Y18) communicating with the refrigerant chamber (Y19) and with refrigerant passages (51c, 51k) outside the control valve member (Y1); a drive unit (Y123, Y124, Y125) that displaces when the temperature of the drive unit changes; an amplification unit (Y126, Y127) that amplifies the displacement of the drive unit (Y123, Y124, Y125) caused by a change in temperature; and a movable part (Y128) that is moved in the refrigerant chamber (Y19) by transmitting the displacement amplified by the amplifying parts (Y126, Y127), and that adjusts the opening degree of the second refrigerant holes (Y17, Y18) with respect to the refrigerant chamber (Y19).

Description

Valve device

Cross reference to related applications

The present application is based on japanese patent application No. 2019-35222 filed on 28/2/2019 and japanese patent application No. 2020-27187 filed on 20/2/2020, and the contents of the descriptions thereof are incorporated herein by reference.

Technical Field

The present invention relates to a valve device for a refrigeration cycle.

Background

Patent document 1 describes the following technique: in an expansion valve used in a refrigeration cycle, a valve for adjusting the flow rate of refrigerant is driven by a stepping motor.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-14306

According to the research of the inventors, the expansion valve described in patent document 1 has a large size because it includes a stepping motor.

Disclosure of Invention

The invention aims to easily reduce the size of a valve device such as an expansion valve used in a refrigeration cycle compared with the conventional one.

According to one aspect of the present invention, a valve device for a refrigeration cycle includes:

a body having an inlet port, an outlet port, and a valve chamber for allowing a refrigerant flowing from the inlet port to the outlet port to flow therethrough;

a valve body that is displaced in the valve chamber to adjust a flow rate of the refrigerant flowing from the inlet port to the outlet port through the valve chamber; and

a control valve member that varies a pressure acting on a pressure chamber that generates a control pressure for moving the spool,

the control valve member has:

a base portion formed with a refrigerant chamber through which a refrigerant flows, a first refrigerant hole communicating with the refrigerant chamber and communicating with the pressure chamber, and a second refrigerant hole communicating with the refrigerant chamber and communicating with a passage of the refrigerant outside the control valve member;

a driving unit that displaces when its temperature changes;

an amplification unit that amplifies a displacement of the drive unit caused by a change in temperature; and

a movable portion that is moved in the refrigerant chamber by transmitting the displacement amplified by the amplifying portion, and adjusts an opening degree of the second refrigerant hole with respect to the refrigerant chamber,

when the driving portion is displaced due to a change in temperature, the driving portion biases the amplifying portion at a biasing position, so that the amplifying portion is displaced about the hinge as a fulcrum, and the amplifying portion biases the movable portion at a connecting position between the amplifying portion and the movable portion,

the distance from the hinge to the connection position is longer than the distance from the hinge to the urging position.

Since the amplification portion of the control valve member configured as described above functions as a lever, the displacement amount of the driving portion corresponding to the temperature change is amplified by the lever and transmitted to the movable portion. In this way, the displacement amount caused by thermal expansion is amplified by the lever, which contributes to miniaturization compared to a valve device that does not utilize such a lever.

The parenthesized reference numerals attached to the respective components and the like indicate an example of correspondence between the components and the like and specific components and the like described in the embodiments described later.

Drawings

Fig. 1 is a diagram showing a configuration of a refrigeration cycle in the first embodiment.

Fig. 2 is a view showing an installation form of the expansion valve.

Fig. 3 is a sectional view of the expansion valve.

Fig. 4 is an enlarged cross-sectional view of the valve assembly of fig. 3 and its periphery.

Figure 5 is an exploded view of a microvalve.

Fig. 6 is a front view of a microvalve.

Fig. 7 is a sectional view VII-VII in fig. 6, showing a state when no current is applied.

Fig. 8 is a sectional view VIII-VIII of fig. 6, showing a state when no current is applied.

Fig. 9 is a sectional view from VII to VII in fig. 6, showing a state when the maximum power is applied.

Fig. 10 is a sectional view VIII-VIII of fig. 6, showing a state when the maximum power is applied.

Fig. 11 is a graph showing a relationship between the duty ratio and the pressure of the output refrigerant.

Fig. 12 is a sectional view showing a state of a valve when the refrigerant circuit is not in operation.

Fig. 13 is a cross-sectional view showing a state of the valve when the duty ratio is zero when the refrigerant circuit is operated.

Fig. 14 is a cross-sectional view showing a state of the valve when the duty ratio is 100% when the refrigerant circuit is operated.

Fig. 15 is a cross-sectional view of a microvalve in a second embodiment.

Fig. 16 is an enlarged view of the XVI portion of fig. 15.

Fig. 17 is a sectional view of an expansion valve in the third embodiment.

Fig. 18 is a sectional view of an expansion valve in the fourth embodiment.

Fig. 19 is a cross-sectional view XIX-XIX of fig. 18.

Fig. 20 is a cross-sectional view XX-XX of fig. 19.

Fig. 21 is a view from XXI of fig. 18.

Figure 22 is an exploded view of a microvalve.

Fig. 23 is a cross-sectional view of the microvalve, showing a state when no current is applied.

Fig. 24 is a sectional view of the microvalve, showing a state at the time of energization.

Fig. 25 is a cross-sectional view showing a state when the expansion valve is opened.

Fig. 26 is a sectional view showing a state when the expansion valve is closed.

Fig. 27 is a partial sectional view of an expansion valve in the fifth embodiment.

Fig. 28 is a cross-sectional view XXVIII-XXVIII of fig. 27.

Fig. 29 is a sectional view of an expansion valve in the sixth embodiment.

Fig. 30 is a sectional view of an expansion valve in the seventh embodiment.

Fig. 31 is a sectional view of an expansion valve in the eighth embodiment.

FIG. 32 is a cross-sectional view of XXXII-XXXII of FIG. 31.

Fig. 33 is a sectional view of an expansion valve in the ninth embodiment.

FIG. 34 is a cross-sectional view of XXXIV-XXXIV of FIG. 33.

FIG. 35 is a cross-sectional view of XXXV-XXXV of FIG. 34.

Fig. 36 is a sectional view of an expansion valve in the tenth embodiment.

Detailed Description

(first embodiment)

The first embodiment will be explained below. As shown in fig. 1, the expansion valve 5 is an electric expansion valve and is applied to a vapor compression refrigeration cycle 1 of a vehicle air conditioner. The refrigeration cycle 1 employs a freon refrigerant (R134a) as a refrigerant, and constitutes a subcritical cycle in which the pressure of a high-pressure refrigerant does not exceed the critical pressure of the refrigerant. First, the compressor 2 of the refrigeration cycle 1 receives driving force from a vehicle-running engine, not shown, via an electromagnetic clutch or the like, and sucks and compresses refrigerant. The compressor 2 may be an electric compressor driven by a driving force output from an electric motor, not shown.

The condenser 3 is a heat-radiating heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the compressor 2 and outside air blown by a cooling fan (not shown) (i.e., air outside the vehicle cabin) to radiate heat from the high-pressure refrigerant and condense the high-pressure refrigerant.

A receiver 4 is connected to an outlet side of the condenser 3, and the receiver 4 separates the high-pressure refrigerant flowing out of the condenser 3 into a gas-phase refrigerant and a liquid-phase refrigerant and accumulates the remaining liquid-phase refrigerant in the cycle. An expansion valve 5 is connected to a liquid-phase refrigerant outlet of the receiver 4. The expansion valve 5 is disposed on the vehicle compartment side of a firewall that separates the vehicle interior from the vehicle exterior.

The expansion valve 5 is a valve device for decompressing and expanding the high-pressure refrigerant flowing out of the receiver 4. The expansion valve 5 changes a throttle flow area (i.e., a valve opening degree) based on the temperature and pressure of the low-pressure refrigerant flowing out of the evaporator 6 so that the superheat degree of the low-pressure refrigerant flowing out of the evaporator 6 approaches a predetermined value, thereby adjusting the flow rate of the refrigerant flowing out to the refrigerant inlet side of the evaporator 6. The details of the expansion valve 5 will be described later. The temperature and pressure are physical quantities.

The evaporator 6 is disposed in an air conditioning case 7, and the air conditioning case 7 is disposed in an instrument panel of the vehicle or the like. The evaporator exchanges heat between the low-pressure refrigerant decompressed and expanded by the expansion valve 5 and the air forced by the blower 8 to flow through the air conditioning case 7. By this heat exchange, the air is cooled, and the low-pressure refrigerant evaporates. The cooled air is sent into the vehicle interior by the blower 8.

Next, the detailed structure of the expansion valve 5 will be described. As shown in fig. 2, the expansion valve 5 is fixed to the air-conditioning casing 7 from the outside thereof. The outlet side of the evaporator 6 is connected to the suction side of the compressor 2 via an evaporated refrigerant passage 51f formed inside the expansion valve 5.

As shown in fig. 2 and 3, the expansion valve 5 includes a main body 51, a valve body 52, a coil spring 53, a main body 54, a valve assembly Y0, and the like. First, the main body 51 is a portion constituting a housing of the expansion valve 5, a refrigerant passage in the expansion valve 5, and the like, and is formed by performing a hole forming process or the like on a cylindrical or square-cylindrical metal block. The main body 51 has a first inlet 51a, a first outlet 51b, a second inlet 51d, a second outlet 51e, a valve chamber 51g, a throttle passage 51h, and the like.

A first inlet 51a connected to the outlet of the condenser 3 and allowing the high-pressure liquid-phase refrigerant to flow therein, and a first outlet 51b allowing the refrigerant flowing from the first inlet 51a to flow out to the inlet of the evaporator 6 are formed as the refrigerant inlet and outlet. Therefore, in the present embodiment, the high-pressure refrigerant passage 51c is formed by a refrigerant passage from the first inlet 51a to the first outlet 51 b. The high-pressure refrigerant passage 51c corresponds to the first passage.

Further, as the other refrigerant inlet and outlet, a second inlet 51d through which the low-pressure refrigerant flowing out of the evaporator 6 flows in, and a second outlet 51e through which the refrigerant flowing in through the second inlet 51d flows out to the suction side of the compressor 2 are formed. Therefore, in the present embodiment, the refrigerant passage from the second inlet 51d to the second outlet 51e forms the post-evaporation refrigerant passage 51 f.

The valve chamber 51g is a space provided in the high-pressure refrigerant passage 51c and accommodating a valve body 52 described later therein. The valve chamber 51g corresponds to a pressure chamber. More specifically, the valve chamber 51g directly communicates with the first inlet 51a, and communicates with the first outlet 51b via the orifice passage 51 h. The orifice passage 51h is provided in the high-pressure refrigerant passage 51c, and is a passage for guiding the refrigerant flowing into the valve chamber 51g from the first inlet 51a to the first outlet 51b side from the valve chamber 51g side while decompressing and expanding the refrigerant flowing into the valve chamber 51g from the first inlet 51 a. The orifice passage 51h is formed between the valve body 52 and the valve seat 51 j.

The valve seat 51j is formed in the body 51 so as to narrow the refrigerant flow path at the downstream end of the valve chamber 51 g. The valve body 52 is a valve body that adjusts the refrigerant passage area of the throttle passage 51h continuously or in a plurality of three or more stages by being displaced relative to the valve seat 51 j. The refrigerant passage from the orifice passage 51h to the first outlet 51b is a low-pressure refrigerant passage 51 k. The low-pressure refrigerant passage 51k corresponds to the second passage.

The low-pressure introduction passage 51q is connected to the low-pressure refrigerant passage 51 k. The low-pressure introduction passage 51q is formed in the main body 51, and has one end communicating with the low-pressure refrigerant passage 51k and the other end communicating with the third communication hole YV3 of the valve assembly Y0.

The high-pressure refrigerant passage 51c is connected to a high-pressure introduction passage 51P. The high-pressure introduction passage 51P is formed in the main body 51, and has one end communicating with the high-pressure refrigerant passage 51c and the other end communicating with the second communication hole YV2 of the valve assembly Y0.

The coil spring 53 is housed in the valve chamber 51g, and biases the valve body 52 to the side for closing the throttle passage 51 h. Specifically, the coil spring 53 is disposed in the back pressure chamber 51m in the valve chamber 51 g. The back pressure chamber 51m is formed on the opposite side of the throttle passage 51h with respect to the valve body 52. The back pressure chamber 51m communicates with the first communication hole YV1 of the valve assembly Y0. Hereinafter, a space in the valve chamber 51g on the opposite side of the back pressure chamber 51m with respect to the valve body 52 is referred to as a front chamber 51 s. The valve chamber 51g is partitioned into a back pressure chamber 51m and a front side chamber 51s by a spool 52.

The main unit 54 includes a housing 54a, a circuit board 54b, a composite sensor 54c, and a drive circuit 54 d. The housing 54a is a resin-made member fixed to the main body 51 and enclosing a housing space in which the circuit board 54b, the composite sensor 54c, and the drive circuit 54d are housed. An opening 51r that opens into the accommodating space is formed in the wall of the main body 51 surrounding the post-evaporation refrigerant passage 51 f. The circuit board 54b is fixed to the housing 54a, and the composite sensor 54c, the drive circuit 54d, and the like are mounted thereon.

The composite sensor 54c includes a housing 541, a sensing portion 542, a lead portion 543, and an O-ring 544. A resin case 541 is integrally fixed to the main body 51 in a housing space surrounded by the case 54 a. More specifically, the housing 541 is inserted through an opening 51r formed in the main body 51. Therefore, the housing 541 has a portion located in the post-evaporation refrigerant passage 51f and a portion located in the above-described housing space.

O-ring 544 is interposed between housing 541 and main body 51, and suppresses leakage of the refrigerant from evaporated refrigerant passage 51f into housing 54 a. The conductive lead portion 543 is connected to a wiring printed on the circuit board 54 b. Since the composite sensor 54c faces the circuit board 54b with a gap therebetween, the lead portions 543 can be easily arranged.

Sensing unit 542 is fixed to a portion of casing 541 located in evaporated refrigerant passage 51 f. The sensing unit 542 outputs a pressure signal corresponding to the pressure of the refrigerant in the evaporated refrigerant passage 51f and a temperature signal corresponding to the temperature of the refrigerant in the evaporated refrigerant passage 51 f.

The sensing unit 542 may include, for example, a pressure sensor and a temperature sensor that is separate from the pressure sensor. Alternatively, the sensing portion 542 may have four measuring resistors and a thin-walled diaphragm to which the bridge circuit is attached. Each of the measuring resistors may be configured as a thin film resistor formed on the diaphragm.

Each of the measuring resistors is a resistance element whose resistance value changes according to the strain of the diaphragm. Each of the measuring resistors is an element whose resistance value changes depending on temperature. These metering resistors are electrically connected to each other in such a manner as to constitute a wheatstone bridge circuit. A constant current is supplied from the drive circuit 54d to the wheatstone bridge circuit via the circuit board 54b, the lead portion 543, and a wiring not shown. As a result, a pressure signal corresponding to the strain of the diaphragm and a temperature signal corresponding to the temperature of the diaphragm are output from the sensing unit 542 due to the piezoresistive effect of each measurement resistor.

Specifically, the sensing unit 542 detects a change in the resistance of the plurality of measuring resistors corresponding to the strain of the diaphragm as a change in the midpoint voltage of the wheatstone bridge circuit, and outputs the midpoint voltage as a pressure signal. On the other hand, the sensing unit 542 detects a change in resistance of the plurality of measuring resistors corresponding to the temperature of the sensing unit 542 as a bridge voltage of the wheatstone bridge circuit, and outputs the bridge voltage as a temperature signal.

The pressure signal and the temperature signal output from the sensing portion 542 are transmitted from the sensing portion 542 to the circuit board 54b via a wiring not shown and a lead portion 543 electrically connected to the wiring. The pressure signal and the temperature signal transmitted to the circuit substrate 54b are input to the drive circuit 54d via a pattern printed on the circuit substrate 54 b.

The drive circuit 54d controls the operation of the valve assembly Y0 based on the pressure signal and the temperature signal input from the composite sensor 54c via the circuit board 54 b. The drive circuit 54d can be realized by, for example, a microcomputer, or can be realized by hardware having a dedicated circuit configuration.

[ Structure of valve Assembly Y0 ]

Here, the structure of the valve assembly Y0 will be described with reference to fig. 3, 4, 5, 6, 7, and 8. As shown in fig. 3 and 4, the valve assembly Y0 includes a micro valve Y1, a valve housing Y2, a seal member Y3, three O-rings Y4, Y5a, and Y5b, two harnesses Y6, Y7, and a switching plate Y8.

Microvalve Y1 is a plate-shaped control valve member and is mainly composed of a semiconductor chip. Microvalve Y1 may not have a component other than a semiconductor chip. Therefore, the micro valve Y1 can be configured to be small. The length of the microvalve Y1 in the thickness direction is, for example, 2mm, the length of the microvalve Y1 in the longitudinal direction orthogonal to the thickness direction is, for example, 10mm, and the length of the microvalve Y in the short side direction orthogonal to both the longitudinal direction and the thickness direction is, for example, 5mm, but the invention is not limited thereto. The flow channel structure of the micro valve Y1 changes due to the fluctuation of the power supplied to the micro valve Y1. Microvalve Y1 functions as a pilot valve.

The harnesses Y6 and Y7 extend from the surface on the opposite side of the valve housing Y2 out of the two plate surfaces on the front and back surfaces of the micro valve Y1, and are connected to a power supply (i.e., the drive circuit 54d) located outside the valve assembly Y0 through the inside of the seal member Y3 and the valve housing Y2. The end portions of the harnesses Y6, Y7 on the side opposite to the side of the micro valve Y1 are connected to the drive circuit 54 d. Thus, electric power can be supplied from the drive circuit 54d to the micro valve Y1 through the harnesses Y6 and Y7.

The switching plate Y8 is a plate-shaped member disposed between the micro valve Y1 and the valve housing Y2. The switching panel Y8 is a glass substrate. One of the two plate surfaces on the front and back surfaces of the switching plate Y8 is fixed to the microvalve Y1 by an adhesive, and the other is fixed to the valve housing Y2 by an adhesive. The switching plate Y8 is provided with flow paths Y81, Y82, and Y83 for connecting three refrigerant holes Y16, Y17, and Y18 of the micro valve Y1, which will be described later, to three communication holes YV1, YV2, and YV3 of the valve housing Y2. These flow paths Y81, Y82, and Y83 are flow paths for absorbing a difference between the pitch between the three refrigerant holes Y16, Y17, and Y18 aligned in a row and the pitch between the three communication holes YV1, YV2, and YV3 aligned in a row. The pitch between the communication holes YV1, YV2, YV3 is larger than the pitch between the refrigerant holes Y16, Y17, Y18. The flow paths Y81, Y82, and Y83 penetrate from one to the other of the two plate surfaces located on the front and back surfaces of the conversion plate Y8. Therefore, the distances between the ends of the passages Y81, Y82, and Y83 on the communication holes YV1, YV2, and YV3 sides are larger than the distances between the ends of the passages Y81, Y82, and Y83 on the refrigerant hole Y16, Y17, and Y18 sides.

The valve housing Y2 is a resin housing that houses the micro valve Y1 and the switch plate Y8. The valve housing Y2 is formed by resin molding with polyphenylene sulfide as a main component. The valve housing Y2 is a box body having a bottom wall on one side and being open on the other side. The bottom wall of the valve housing Y2 is sandwiched between the main body 51 and the microvalve Y1 in such a manner that the microvalve Y1 and the switch plate Y8 do not directly contact the main body 51. One surface of the bottom wall is fixed in contact with the main body 51, and the other surface is fixed in contact with the switching plate Y8.

With this configuration, the valve housing Y2 can absorb the difference in linear expansion coefficient between the micro valve Y1 and the main body 51. This is because the linear expansion coefficient of the valve housing Y2 is a value between the linear expansion coefficient of the micro valve Y1 and the linear expansion coefficient of the main body 51. The linear expansion coefficient of the switching plate Y8 is a value between the linear expansion coefficient of the micro valve Y1 and the linear expansion coefficient of the valve housing Y2.

The bottom wall of the valve housing Y2 has a plate-shaped base portion Y20 facing the microvalve Y1, and columnar first, second, and third projections Y21, Y22, Y23 projecting from the base portion Y20 in a direction away from the microvalve Y1.

The first projection Y21, the second projection Y22, and the third projection Y23 are fitted into the recess formed in the main body 51. The first protrusion Y21 has a first through hole YV1 penetrating from the side end of the micro valve Y1 to the opposite side end thereof. The second protrusion Y22 has a second communication hole YV2 that extends from the side end of the micro valve Y1 to the opposite side end thereof. The third protrusion Y23 has a third communication hole YV3 that extends from the side end of the micro valve Y1 to the opposite side end thereof. The first communication hole YV1, the second communication hole YV2, and the third communication hole YV3 are aligned in a row, and the first communication hole YV1 is located between the second communication hole YV2 and the third communication hole YV 3.

The side end of the micro valve Y1 of the first communication hole YV1 communicates with the side end of the valve housing Y2 of the flow path Y81 formed in the switching plate Y8. The end of the second communication hole YV2 on the micro valve Y1 side communicates with the end of the valve housing Y2 side of the flow path Y82 formed in the switching plate Y8. The micro valve Y1 side end of the third communication hole YV3 communicates with the valve housing Y2 side end of the flow path Y83 formed in the switching plate Y8.

The seal member Y3 is an epoxy resin member that seals the other side of the valve housing Y2 that is open. The sealing member Y3 covers the entire plate surface on the opposite side of the switching plate Y8 side of the two plate surfaces of the front and back surfaces of the microvalve Y1. Further, the seal member Y3 covers a part of the plate surface on the side opposite to the bottom wall side of the valve housing Y2, out of the two plate surfaces of the front and back surfaces of the switch plate Y8. In addition, the sealing member Y3 achieves waterproofing and insulation of the harnesses Y6, Y7 by covering the harnesses Y6, Y7. The sealing member Y3 is formed by resin potting or the like.

The O-ring Y4 is attached to the outer periphery of the first protrusion Y21, and seals between the main body 51 and the first protrusion Y21, thereby suppressing leakage of the refrigerant to the outside of the expansion valve 5 and the outside of the refrigeration cycle. The O-ring Y5a is attached to the outer periphery of the second protrusion Y22, and seals between the main body 51 and the second protrusion Y22, thereby suppressing leakage of the refrigerant to the outside of the expansion valve 5 and the outside of the refrigeration cycle. The O-ring Y5b is attached to the outer periphery of the third protrusion Y23, and seals between the main body 51 and the third protrusion Y23, thereby suppressing leakage of the refrigerant to the outside of the expansion valve 5 and the outside of the refrigeration cycle.

Here, the structure of the micro valve Y1 will be further described. As shown in fig. 5 and 6, the microvalve Y1 is a MEMS having a first outer layer Y11, an intermediate layer Y12, and a second outer layer Y13, all of which are made of semiconductor. MEMS is a short term for Micro Electro Mechanical Systems (Micro Electro Mechanical Systems). The first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13 are rectangular plate-shaped members each having the same outer shape, and are laminated in the order of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13. That is, the intermediate layer Y12 is sandwiched by the first outer layer Y11 and the second outer layer Y13 from both sides. The second outer layer Y13 of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13 is disposed on the side of the valve housing Y2 closest to the bottom wall. The structures of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13, which will be described later, are formed by a semiconductor manufacturing process such as chemical etching.

The first outer layer Y11 is a conductive semiconductor member having a nonconductive oxide film on the surface. As shown in fig. 5, two through holes Y14 and Y15 penetrating the front surface and the back surface are formed in the first outer layer Y11. The ends of the harness wires Y6 and Y7, which are close to the micro valve Y1, are inserted into the through holes Y14 and Y15, respectively.

The second outer layer Y13 is a conductive semiconductor member having a nonconductive oxide film on the surface. As shown in fig. 5, 7, and 8, the second outer layer Y13 has a first refrigerant hole Y16, a second refrigerant hole Y17, and a third refrigerant hole Y18 penetrating the front and rear surfaces.

As shown in fig. 8, the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 communicate with the flow paths Y81, Y82, and Y83 of the switching plate Y8, respectively. The first refrigerant port Y16, the second refrigerant port Y17, and the third refrigerant port Y18 are aligned in a row. The first refrigerant hole Y16 is disposed between the second refrigerant hole Y17 and the third refrigerant hole Y18. The hydraulic diameters of the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 are, for example, 0.1mm to 3mm, but not limited thereto.

The intermediate layer Y12 is a conductive semiconductor member, and is sandwiched between the first outer layer Y11 and the second outer layer Y13. The intermediate layer Y12 is in contact with the oxide film of the first outer layer Y11 and the oxide film of the second outer layer Y13, and thus is not electrically conductive to the first outer layer Y11 and the second outer layer Y13. As shown in fig. 7, the intermediate layer Y12 includes a first fixed portion Y121, a second fixed portion Y122, a plurality of first ribs Y123, a plurality of second ribs Y124, a spine (spine) Y125, an arm Y126, a beam Y127, and a movable portion Y128.

The first fastening portions Y121 are members fastened to the first outer layer Y11 and the second outer layer Y13. The first fixing portion Y121 is formed so as to surround the second fixing portion Y122, the first rib Y123, the second rib Y124, the spine Y125, the arm Y126, the beam Y127, and the movable portion Y128 in the same one refrigerant chamber Y19. The refrigerant chamber Y19 is a chamber surrounded by the first fixing portion Y121, the first outer layer Y11, and the second outer layer Y13. The first fixing portion Y121, the first outer layer Y11, and the second outer layer Y13 correspond to the base portion as a whole. The harnesses Y6 and Y7 are harnesses for shifting the plurality of first ribs Y123 and the plurality of second ribs Y124 by changing the temperature thereof.

The fixation of the first fastening parts Y121 with respect to the first and second outer layers Y11 and Y13 is performed in such a manner that: refrigerant is prevented from leaking from refrigerant chamber Y19 through other than first refrigerant hole Y16, second refrigerant hole Y17, and third refrigerant hole Y18 and out of micro valve Y1.

The second fastening portion Y122 is fastened to the first outer layer Y11 and the second outer layer Y13. The second fixing portion Y122 is surrounded by the first fixing portion Y121 and is disposed apart from the first fixing portion Y121.

The plurality of first ribs Y123, the plurality of second ribs Y124, the spine Y125, the arms Y126, the beams Y127, and the movable portion Y128 are not fixed to the first outer layer Y11 and the second outer layer Y13, and are displaceable with respect to the first outer layer Y11 and the second outer layer Y13.

The spine Y125 has an elongated bar shape extending in the short side direction of the rectangular shape of the intermediate layer Y12. One end in the longitudinal direction of the spine Y125 is connected to the beam Y127.

The plurality of first ribs Y123 are disposed on one side of the spine Y125 in the direction orthogonal to the longitudinal direction of the spine Y125. Also, a plurality of first ribs Y123 are arranged along the length direction of the spine Y125. Each of the first ribs Y123 has an elongated rod shape and can expand and contract depending on the temperature.

Each of the first ribs Y123 is connected at one end in the longitudinal direction thereof to the first fixing portion Y121 and at the other end thereof to the spine Y125. Each of the first ribs Y123 is inclined with respect to the spine Y125 so as to be shifted toward the longitudinal beam Y127 of the spine Y125 from the first fixing portion Y121 side toward the spine Y125 side. Also, the plurality of first ribs Y123 extend parallel to each other.

The plurality of second ribs Y124 are arranged on the other side of the spine Y125 in the direction orthogonal to the longitudinal direction of the spine Y125. Also, a plurality of second ribs Y124 are arranged along the length direction of the spine Y125. Each of the second ribs Y124 has an elongated bar shape and can expand and contract depending on the temperature.

Each of the second ribs Y124 is connected at one end in the longitudinal direction thereof to the second fixing portion Y122 and at the other end thereof to the spine Y125. Each second rib Y124 is inclined with respect to the spine Y125 so as to be shifted toward the side of the beam Y127 in the longitudinal direction of the spine Y125 from the second fixing portion Y122 side toward the spine Y125 side. Also, the plurality of second ribs Y124 extend parallel to each other.

The plurality of first ribs Y123, the plurality of second ribs Y124, and the spine Y125 correspond to the driving portion as a whole.

The arm Y126 has an elongated bar shape extending in non-orthogonal and parallel relation to the spine Y125. One end of the arm Y126 in the longitudinal direction is connected to the beam Y127, and the other end is connected to the first fixing portion Y121.

The beam Y127 has an elongated bar shape extending in a direction crossing at about 90 ° with respect to the spine Y125 and the arm Y126. One end of the beam Y127 is connected to the movable portion Y128. The arm Y126 and the beam Y127 correspond to the enlargement portion as a whole.

The connection position YP1 of the arm Y126 and the beam Y127, the connection position YP2 of the spine Y125 and the beam Y127, and the connection position YP3 of the beam Y127 and the movable portion Y128 are arranged in this order along the longitudinal direction of the beam Y127. When the connection point between the first fixing portion Y121 and the arm Y126 is defined as the hinge YP0, the linear distance from the hinge YP0 to the connection position YP3 is longer than the linear distance from the hinge YP0 to the connection position YP2 in the plane parallel to the plate surface of the intermediate layer Y12. For example, a value obtained by dividing the linear distance of the former by the linear distance of the latter may be 1/5 or less, or 1/10 or less.

The outer shape of the movable portion Y128 has a rectangular shape extending in a direction of substantially 90 ° with respect to the longitudinal direction of the beam Y127. The movable portion Y128 is movable integrally with the beam Y127 in the refrigerant chamber Y19. The movable portion Y128 has a frame shape surrounding the through hole Y120 penetrating through the front and back surfaces of the intermediate layer Y12. Therefore, the through hole Y120 also moves integrally with the movable portion Y128. The through hole Y120 is a part of the refrigerant chamber Y19.

The movable portion Y128 moves as described above to change the opening degree of the second refrigerant hole Y17 with respect to the through hole Y120 and the opening degree of the third refrigerant hole Y18 with respect to the through hole Y120. The first refrigerant port Y16 is always in full-open communication with the through hole Y120.

Further, the end of the micro valve Y1 of the harness Y6 that has passed through the through hole Y14 of the first outer layer Y11 shown in fig. 5 is connected to the first application point Y129 in the vicinity of the portion of the first fixing portion Y121 that is connected to the plurality of first ribs Y123. Further, the end of the micro valve Y1 of the harness Y7 passing through the through hole Y15 of the first outer layer Y11 shown in fig. 5 is connected to the second application point Y130 of the second fixing portion Y122.

[ operation of valve Assembly Y0 ]

Here, the operation of the valve assembly Y0 will be explained. When the energization of the microvalve Y1 is started, a voltage is applied between the first application point Y129 and the second application point Y130 through the harnesses Y6 and Y7. Then, a current flows through the plurality of first ribs Y123 and the plurality of second ribs Y124. The plurality of first ribs Y123 and the plurality of second ribs Y124 generate heat due to the current. As a result, the plurality of first ribs Y123 and the plurality of second ribs Y124 expand in the longitudinal direction thereof, respectively.

As a result of such thermal expansion, the plurality of first ribs Y123 and the plurality of second ribs Y124 urge the spine Y125 toward the connection position YP 2. The urged spine Y125 presses the beam Y127 at the connection position YP 2. Thus, the connection position YP2 corresponds to the biasing position. As a result, the member constituted by the beam Y127 and the arm Y126 integrally changes its posture with the hinge YP0 as a fulcrum and the connection position YP2 as a point of force. As a result, the movable portion Y128 connected to the end portion of the beam Y127 on the side opposite to the arm Y126 also moves toward the side of the spine Y125 in the longitudinal direction thereof, which presses the beam Y127.

When the energization of the microvalve Y1 is stopped, the voltage application from the harnesses Y6 and Y7 to the first application point Y129 and the second application point Y130 is stopped. Accordingly, the current does not flow through the plurality of first ribs Y123 and the plurality of second ribs Y124, and the temperatures of the plurality of first ribs Y123 and the plurality of second ribs Y124 are reduced. As a result, the plurality of first ribs Y123 and the plurality of second ribs Y124 are contracted in the longitudinal direction thereof, respectively.

As a result of such thermal contraction, the plurality of first ribs Y123 and the plurality of second ribs Y124 urge the spine Y125 to the opposite side of the connection position YP 2. The forced spine Y125 stretches beam Y127 at the connection position YP 2. As a result, the member constituted by the beam Y127 and the arm Y126 integrally changes its posture with the hinge YP0 as a fulcrum and the connection position YP2 as a point of force. As a result, the movable portion Y128 connected to the end portion of the beam Y127 on the side opposite to the arm Y126 also moves to the side of the spine Y125 in the longitudinal direction, which stretches the beam Y127. As a result of this movement, the movable portion Y128 stops at a predetermined non-energization position. The non-energized position corresponds to the first position.

When current is applied to the micro valve Y1, the amount of movement of the movable unit Y128 with respect to the non-energized position increases as the electric power supplied from the harnesses Y6 and Y7 to the micro valve Y1 via the first application point Y129 and the second application point Y130 increases. This is because the higher the power supplied to the microvalve Y1, the higher the temperature of the first rib Y123 and the second rib Y124, and the greater the degree of expansion.

For example, when PWM control is performed on the voltages applied from the harnesses Y6 and Y7 to the first application point Y129 and the second application point Y130, the amount of movement of the movable portion Y128 with respect to the non-energized position increases as the duty ratio of the voltage increases. Hereinafter, the duty ratio of the voltage in the PWM control is simply referred to as the duty ratio.

As shown in fig. 7 and 8, when the movable portion Y128 is in the non-energized position, the through hole Y120 overlaps the first refrigerant hole Y16 and the third refrigerant hole Y18 in the direction perpendicular to the plate surface of the intermediate layer Y12, but does not overlap the second refrigerant hole Y17 in this direction. The second refrigerant hole Y17 overlaps the movable portion Y128 in the direction orthogonal to the plate surface of the intermediate layer Y12. That is, at this time, the first refrigerant hole Y16 and the third refrigerant hole Y18 are fully opened with respect to the through hole Y120, and the second refrigerant hole Y17 is fully closed with respect to the through hole Y120. Therefore, in this case, the first refrigerant hole Y16 communicates with the third refrigerant hole Y18 via the movable portion Y128, and the second refrigerant hole Y17 is cut off from both the first refrigerant hole Y16 and the third refrigerant hole Y18. As a result, the refrigerant can flow between the first communication hole YV1 and the third communication hole YV3 through the flow path Y81, the first refrigerant hole Y16, the through hole Y120, the third refrigerant hole Y18, and the flow path Y83.

As shown in fig. 9 and 10, when the movable portion Y128 is at the position farthest from the non-energized position due to the energization to the micro valve Y1, the position of the movable portion Y128 at this time is referred to as the maximum energized position. The maximum power-on position corresponds to the second position. When movable portion Y128 is at the maximum energization position, the electric power supplied to microvalve Y1 is at the maximum within the control range. For example, when the movable portion Y128 is at the maximum energization position, the duty ratio is the maximum value (e.g., 100%) in the control range in the PWM control.

When the movable portion Y128 is at the maximum energization position, the through hole Y120 overlaps with the first refrigerant hole Y16 and the second refrigerant hole Y17 in the direction perpendicular to the plate surface of the intermediate layer Y12, but does not overlap with the third refrigerant hole Y18 in this direction. The third refrigerant hole Y18 overlaps the movable portion Y128 in the direction orthogonal to the plate surface of the intermediate layer Y12. That is, at this time, the first refrigerant hole Y16 and the second refrigerant hole Y17 are fully opened with respect to the through hole Y120, and the third refrigerant hole Y18 is fully closed with respect to the through hole Y120. Therefore, in this case, the first refrigerant hole Y16 communicates with the second refrigerant hole Y17 via the movable portion Y128, and the third refrigerant hole Y18 is cut off from both the first refrigerant hole Y16 and the second refrigerant hole Y17. As a result, the refrigerant can flow between the first communication hole YV1 and the second communication hole YV2 through the flow path Y81, the first refrigerant hole Y16, the through hole Y120, the second refrigerant hole Y17, and the flow path Y83.

The electric power supplied to microvalve Y1 (for example, in PWM control) is adjusted in a plurality of stages or continuously in a range smaller than the maximum electric power and larger than zero. This makes it possible to stop the movable portion Y128 at any intermediate position between the non-energization-time position and the maximum energization-time position. For example, the electric power supplied to microvalve Y1 may be half the maximum value in the control range so that movable portion Y128 is stopped at a position (i.e., the center position) equidistant from the maximum energization position and the non-energization position. For example, the duty ratio in the PWM control may be 50%.

When the movable portion Y128 stops at the intermediate position, the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 all communicate with the through hole Y120. However, the second refrigerant hole Y17 and the third refrigerant hole Y18 are not fully opened with respect to the through hole Y120, but are intermediate opening degrees smaller than 100% and larger than 0%. As the intermediate position of the movable portion Y128 is closer to the maximum energization position, the intermediate opening degree of the third refrigerant hole Y18 with respect to the through hole Y120 decreases, and the intermediate opening degree of the second refrigerant hole Y17 increases.

In the present embodiment, as will be described later, a high pressure is applied to the second refrigerant hole Y17, and a low pressure higher than the high pressure is applied to the third refrigerant hole Y18. At this time, when the movable portion Y128 is at the intermediate position, an intermediate pressure higher than the low pressure and lower than the high pressure acts on the outside of the micro valve Y1 from the first refrigerant hole Y16. The value of the intermediate pressure varies depending on the degree of opening of the second refrigerant hole Y17 with respect to the movable portion Y128 and the degree of opening of the third refrigerant hole Y18 with respect to the movable portion Y128.

Fig. 11 illustrates the relationship between the duty ratio and the pressure (i.e., the control pressure or the outlet pressure) acting from the first refrigerant hole Y16 to the outside of the micro valve Y1 in the case where the voltage applied from the harnesses Y6, Y7 to the first application point Y129 and the second application point Y130 is PWM-controlled. As shown in this figure, the larger the duty ratio, the higher the control pressure becomes in proportion to the increase in the duty ratio. Further, when the duty ratio is 100%, the control pressure is equal to the high pressure. When the duty ratio is 0%, that is, when the current is not supplied, the control pressure is equal to the low pressure.

As described above, the beam Y127 and the arm Y126 function as levers having the hinge YP0 as a fulcrum, the connection position YP2 as a force point, and the connection position YP3 as an action point. As described above, the linear distance from the hinge YP0 to the connection position YP3 is longer than the linear distance from the hinge YP0 to the connection position YP2 in the plane parallel to the plate surface of the intermediate layer Y12. Therefore, the movement amount of the connection position YP3 as the point of action is larger than the movement amount of the connection position YP2 as the point of force. Therefore, the displacement amount due to the thermal expansion is amplified by the lever and transmitted to the movable portion Y128.

The refrigerant flow path in the microvalve Y1 has a U-turn structure. Specifically, the refrigerant flows into micro valve Y1 from one surface of micro valve Y1, passes through micro valve Y1, and then flows out of micro valve Y1 from the same surface of micro valve Y1. Similarly, the flow path of the refrigerant in the valve assembly Y0 has a U-turn structure. Specifically, the refrigerant flows into the valve assembly Y0 from one surface of the valve assembly Y0, passes through the valve assembly Y0, and then flows out of the valve assembly Y0 from the surface on the same side of the valve assembly Y0. This is because, as described above, the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 are formed in the same intermediate layer Y12. The direction orthogonal to the plate surface of the intermediate layer Y12 is the stacking direction of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13.

The microvalve Y1 configured in this way can be easily miniaturized compared to an electromagnetic valve and a stepping motor. One reason for this is that, as described above, the micro valve Y1 is formed of a semiconductor chip. In addition, as described above, the displacement amount due to thermal expansion is amplified by the lever, which also contributes to downsizing as compared with a valve device using a solenoid valve or a stepping motor without using such a lever. In addition, since the displacements of the plurality of first ribs Y123 and the plurality of second ribs Y124 are generated by heat, the noise reduction effect is high.

Further, since the lever is used, the amount of displacement due to thermal expansion can be suppressed as compared with the amount of movement of the movable portion Y128, and therefore, the power consumption for driving the movable portion Y128 can be reduced. Further, since the impact sound generated when the solenoid valve is driven can be eliminated, the noise can be reduced.

As described above, since both the micro valve Y1 and the valve assembly Y0 have the refrigerant flow path of the U-turn structure, the intrusion of the main body 51 can be reduced. That is, the depth of the recess formed in the main body 51 to dispose the valve element Y0 can be suppressed. The reason for this is as follows.

For example, it is assumed that the valve assembly Y0 does not have a refrigerant flow path of a U-turn structure, and has a refrigerant inlet port on the body 51 side of the valve assembly Y0 and a refrigerant outlet port on the opposite side of the valve assembly Y0. In this case, it is necessary to form refrigerant flow paths on both surfaces of the valve element Y0. Therefore, when the refrigerant flow paths to both surfaces of the valve assembly Y0 are to be accommodated in the main body 51, the recess formed in the main body 51 is required to be deeper in order to dispose the valve assembly Y0. Further, since the micro valve Y1 itself is small, the intrusion of the main body 51 can be further reduced.

Further, when the harnesses Y6 and Y7 are disposed on the opposite side of the surface of the microvalve Y1 from the surface on which the first refrigerant hole Y16 and the second refrigerant hole Y17 are formed, the harnesses Y6 and Y7 can be placed closer to the atmosphere. Therefore, a sealing structure such as an airtight section for reducing the influence of the refrigerant atmosphere on the harnesses Y6 and Y7 is not required. As a result, the expansion valve 5 can be downsized.

Further, since the micro valve Y1 is lightweight, the expansion valve 5 is lightweight. Further, since the power consumption of micro valve Y1 is small, expansion valve 5 is power-saving.

[ Overall work ]

The operation of the refrigeration cycle configured as described above will be described below.

[ non-operation ]

First, the non-operation of the refrigeration cycle will be described. In this case, the compressor 2 and the blower 8 are not operated, and the refrigerant in the refrigeration cycle does not circulate. In addition, both the composite sensor 54c and the drive circuit 54d do not operate. Further, current is not applied to microvalve Y1. In this case, as described above, the third communication hole YV3 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the second communication hole YV2 and the through hole Y120 of the micro valve Y1 are cut off from each other. Therefore, as shown in fig. 12, the back pressure chamber 51m and the low-pressure refrigerant passage 51k communicate with each other via the low-pressure introduction passage 51q and the micro valve Y1.

In addition, at this time, the pressure of the refrigerant between the receiver 4 and the expansion valve 5 and the pressure of the refrigerant between the expansion valve 5 and the evaporator 6 are equal to each other. Therefore, the pressure of the refrigerant in the high-pressure refrigerant passage 51c and the pressure of the refrigerant in the low-pressure refrigerant passage 51k are also equal to each other. Therefore, the pressure of the refrigerant in the back pressure chamber 51m communicating with the low-pressure refrigerant passage 51k and the pressure of the front side chamber 51s communicating with the high-pressure refrigerant passage 51c are also equal to each other.

Therefore, the force applied to the valve element 52 by the refrigerant in the back pressure chamber 51m is substantially the same as the force applied to the valve element 52 by the refrigerant in the front side chamber 51 s. Thereby, the valve body 52 is urged by the force of the compressed coil spring 53 to expand, and moves into contact with the valve seat 51j, and the orifice passage 51h is closed.

[ operation ]

Next, a state in which the refrigeration cycle is operating will be described. In this case, the compressor 2 and the blower 8 are operated. Thereby, the pressure of the refrigerant in the high-pressure refrigerant passage 51c is higher than the pressure of the refrigerant in the low-pressure refrigerant passage 51 k.

The composite sensor 54c and the drive circuit 54d also operate. Therefore, the micro valve Y1 is energized from the drive circuit 54d via the harnesses Y6, Y7 as necessary.

Specifically, the composite sensor 54c detects the pressure and temperature of the refrigerant to pass through the post-evaporation refrigerant passage 51 f. That is, the temperature sensing unit of the composite sensor 54c outputs a pressure signal and a temperature signal corresponding to the pressure and the temperature of the refrigerant that is to pass through the evaporated refrigerant passage 51 f. The drive circuit 54d acquires the pressure signal and the temperature signal, and determines the electric power to be supplied to the harnesses Y6, Y7 based on the acquired pressure signal and temperature signal. In the following, a case will be described in which the drive circuit 54d performs the electric power supplied to the harnesses Y6, Y7 by PWM control with a constant maximum voltage. Therefore, the drive circuit 54d determines the duty ratio of the voltage applied to the harnesses Y6, Y7 so that the degree of superheat of the low-pressure refrigerant flowing out of the evaporator 6 becomes a predetermined constant value, based on the acquired pressure signal and temperature signal.

Specifically, the drive circuit 54d decreases the duty ratio as the pressure indicated by the pressure signal is constant and the temperature indicated by the temperature signal is higher, that is, as the degree of superheat is higher. This increases the lift amount of the valve body 52, and decreases the superheat degree. The drive circuit 54d increases the duty ratio as the temperature indicated by the temperature signal is constant and the pressure indicated by the pressure signal is higher, that is, the degree of superheat is lower. This reduces the amount of lift of the valve body 52, and increases the degree of superheat.

Then, the drive circuit 54d applies a voltage to the micro valve Y1 via the harnesses Y6, Y7 at the determined duty ratio. Thereby, the superheat of the low-pressure refrigerant flowing out of the evaporator 6 is kept constant.

For example, when the duty ratio is zero, as described above, the third communication hole YV3 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the second communication hole YV2 and the through hole Y120 of the micro valve Y1 are cut off from each other. Therefore, as shown in fig. 13, the back pressure chamber 51m and the low-pressure refrigerant passage 51k communicate with each other via the low-pressure introduction passage 51q and the micro valve Y1.

Therefore, the following states are obtained: the low-pressure refrigerant exists in the back-pressure chamber 51m, and the high-pressure refrigerant from the high-pressure refrigerant passage 51c exists in the front-side chamber 51 s. That is, the pressure of the refrigerant in the front side chamber 51s is higher than the pressure of the refrigerant in the back pressure chamber 51 m. As a result, the valve body 52 is biased toward the back pressure chamber 51m against the force of the coil spring 53 to expand. As a result, the opening degree of the orifice passage 51h is maximized. Therefore, the pressure difference between the high-pressure refrigerant passage 51c and the low-pressure refrigerant passage 51k is small.

For example, when the duty ratio is 100%, as described above, the second communication hole YV2 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the third communication hole YV3 and the through hole Y120 of the micro valve Y1 are cut off from each other. Therefore, as shown in fig. 14, the high-pressure refrigerant passage 51c and the back-pressure chamber 51m communicate with each other through the high-pressure introduction passage 51P and the micro valve Y1.

Therefore, the refrigerant of the same high pressure exists in both the back pressure chamber 51m and the front side chamber 51 s. As a result, the valve body 52 is biased toward the valve seat 51j by the force of the coil spring 53 to expand. As a result, the opening degree of the orifice passage 51h becomes the minimum. However, the opening is greater than zero. Therefore, the pressure difference between the high-pressure refrigerant passage 51c and the low-pressure refrigerant passage 51k becomes large.

In addition, for example, in the case where the duty ratio is larger than zero and smaller than 100%, as already described, the second communication hole YV2 communicates with the first communication hole YV1 via the micro valve Y1, and the third communication hole YV3 communicates with the first communication hole YV1 via the micro valve Y1. As shown in fig. 11, the refrigerant pressure applied from the first refrigerant hole Y16 of the microvalve Y1 to the back pressure chamber 51m via the first communication hole YV1 increases as the duty ratio increases in a range of higher than the low pressure and lower than the high pressure. Therefore, the opening degree of the orifice passage 51h is larger as the duty ratio is smaller in a range larger than the minimum and smaller than the maximum. Here, the low pressure refers to the pressure of the refrigerant in the low-pressure refrigerant passage 51 k. The high pressure refers to the pressure of the refrigerant in the high-pressure refrigerant passage 51c, and is higher than the low pressure.

In the U-turn structure of the microvalve Y1, the second outer layer Y13 is disposed on the side closer to the valve body 52 than the first outer layer Y11. Further, a high-pressure refrigerant passage 51c and a low-pressure refrigerant passage 51k are formed in the main body 51. Therefore, the flow path through which the refrigerant flows from the micro valve Y1 to the body 51 can be shortened as compared with the case where the first outer layer Y11 is disposed on the side closer to the valve body 52 than the second outer layer Y13. Further, the expansion valve 5 can be downsized.

Further, the main unit 54 includes: a composite sensor 54c that detects the temperature and pressure of the refrigerant flowing out of the evaporator 6; and a drive circuit 54d for controlling the temperature of the ribs Y123 and Y124 based on the temperature and pressure detected by the composite sensor 54 c. With this configuration, the expansion valve 5 can autonomously adjust the flow rate of the refrigerant flowing from the high-pressure refrigerant passage 51c to the low-pressure refrigerant passage 51 k.

(second embodiment)

Next, a second embodiment will be explained. The micro valve Y1 of the present embodiment, which is modified to the first embodiment, has a failure detection function. Specifically, the microvalve Y1 includes a failure detection unit Y50 as shown in fig. 15 and 16, in addition to the same configuration as that of the first embodiment.

The failure detecting section Y50 includes a bridge circuit formed in the arm Y126 of the intermediate layer Y12. The bridge circuit includes four metering resistors connected as shown in fig. 16. That is, the failure detection unit Y50 is a bridge circuit whose resistance changes in accordance with the strain of the arm Y126 corresponding to the diaphragm. That is, the failure detecting unit Y50 is a semiconductor piezoresistive strain sensor. The failure detection unit Y50 may be connected to the arm Y126 via an electrically insulating film so as to be nonconductive from the arm Y126.

The two input terminals located at opposite corners of the bridge circuit are connected to wires Y51 and Y52. Then, a voltage for constant current generation is applied to the input terminal through the wirings Y51 and Y52. The wirings Y51 and Y52 are branched from the voltage applied to the microvalve Y1 via the electric wirings Y6 and Y7 (i.e., the microvalve driving voltage) and extend to the two input terminals.

Further, two output terminals located at the other diagonal corners of the bridge circuit are connected to wirings Y53 and Y54. Then, voltage signals corresponding to the amount of strain of the arm Y126 are output from the wirings Y53 and Y54. As will be described later, this voltage signal is used as information for discriminating whether or not microvalve Y1 is operating normally. The voltage signals output from the wirings Y53 and Y54 are input to the drive circuit 54 d.

When the drive circuit 54d acquires a voltage signal corresponding to the strain amount of the arm Y126 via the wirings Y53 and Y54, the drive circuit 54d performs a failure detection process for detecting the presence or absence of a failure of the micro valve Y1 based on the voltage signal. Examples of the failure to be detected include a failure in which the arm Y126 is broken, a failure in which a small foreign object is interposed between the movable portion Y128 and the first outer layer Y11 or the second outer layer Y13, and the movable portion Y128 does not move, and the like.

When the beam Y127 and the movable portion Y128 are displaced in accordance with the expansion and contraction of the plurality of first ribs Y123 and the plurality of second ribs Y124, the amount of strain of the arm Y126 changes. Therefore, the position of the movable portion Y128 can be estimated from the voltage signal corresponding to the amount of strain of the arm Y126. On the other hand, if the micro valve Y1 is normal, there is also a correlation between the amount of current flowing from the harnesses Y6, Y7 to the micro valve Y1 and the position of the movable portion Y128. This energization amount is a control amount for controlling micro valve Y1.

The drive circuit 54d detects the presence or absence of a failure of the microvalve Y1 using this condition. That is, the drive circuit 54d calculates the position of the movable portion Y128 based on a first map set in advance based on the voltage signals from the wirings Y53 and Y54. Then, based on a second map set in advance, the electric power supplied from the harnesses Y6, Y7 to the micro valve Y1, which is necessary to realize the position during normal operation, is calculated from the position of the movable portion Y128. These first and second maps are recorded in the nonvolatile memory of the drive circuit 54 d. The non-volatile memory is a non-volatile tangible storage medium. The correspondence relationship between the level of the voltage signal in the first map and the position may be determined in advance through experiments or the like. The correspondence relationship between the position in the second map and the supply power may be determined in advance by experiments or the like.

Then, the drive circuit 54d compares the calculated electric power with the electric power actually supplied from the harnesses Y6, Y7 to the micro valve Y1. When the absolute value of the difference between the former power and the latter power exceeds the allowable value, the drive circuit 54d determines that the microvalve Y1 has failed, and when the absolute value does not exceed the allowable value, the drive circuit 54d determines that the microvalve Y1 is normal. When determining that the micro valve Y1 has failed, the drive circuit 54d notifies the control device Y55 outside the expansion valve 5 of the failure of the micro valve Y1 via a signal line, not shown.

The control device Y55 may be, for example, an air conditioning ECU that controls operations of a compressor, a blower, an air mix door, an inside/outside air switching door, and the like in a vehicle air conditioner. Alternatively, the control device Y55 may be a meter ECU that displays the vehicle speed, the remaining fuel level, the remaining battery level, and the like in the vehicle. When the controller Y55 receives a notification from the drive circuit 54d that the micro valve Y1 has failed, the controller Y55 performs predetermined failure report control.

The control device Y55 operates the notification device Y56 for notifying the vehicle occupant of the failure notification control. For example, the control device Y55 may turn on a warning lamp. Further, the controller Y55 may cause the image display device to display an image indicating that the micro valve Y1 has failed. Thus, the occupant of the vehicle can notice the failure of the microvalve Y1.

In the failure report control, the control device Y55 may record information indicating that a failure has occurred in the micro valve Y1 in a storage device in the vehicle. The storage device is a non-volatile tangible storage medium. This allows the failure of microvalve Y1 to be recorded outside expansion valve 5.

When it is determined that micro valve Y1 has failed, drive circuit 54d performs energization stop control. In the energization stop control, the drive circuit 54d stops energization of the micro valve Y1 from the harnesses Y6, Y7. By stopping the energization of the micro valve Y1 at the time of failure of the micro valve Y1 in this way, the safety of the micro valve Y1 at the time of failure can be improved.

As described above, the failure detector Y50 outputs the voltage signal for determining whether or not the micro valve Y1 is operating normally, and the drive circuit 54d can easily determine whether or not the micro valve Y1 has failed.

The voltage signal is a signal corresponding to the amount of strain of the arm Y126. Therefore, the presence or absence of a failure of the micro valve Y1 can be easily determined based on the relationship between the amount of current flowing from the harnesses Y6, Y7 to the micro valve Y1 and the voltage signal.

In the present embodiment, it is determined whether or not micro valve Y1 has failed based on a change in resistance constituting the bridge circuit. However, as another method, it may be determined whether or not micro valve Y1 has failed based on a change in capacitance. In this case, a plurality of electrodes are formed on the arm Y126 instead of the bridge circuit, and the plurality of electrodes form a capacitance component. The amount of deformation of the arm Y126 is correlated with the capacitance between the plurality of electrodes. Therefore, the controller Y55 can determine whether or not the micro valve Y1 has failed based on the change in the capacitance between the plurality of electrodes. Further, the modifications of the present embodiment to the first embodiment can also be applied to fourth to tenth embodiments described later.

(third embodiment)

Next, a third embodiment will be explained. The present embodiment is added with the hall element 55 and the magnet 56 to the first embodiment. The hall element 55 and the magnet 56 are configured to detect a distance between the valve element 52 and the valve seat 51j, that is, a lift amount of the valve element 52.

The hall element 55 is fixed in the vicinity of the valve seat 51j in the main body 51. The hall element 55 is disposed so as to surround a flow path connecting the valve chamber 51g and the low-pressure refrigerant passage 51 k. The hall element 55 is electrically connected to the drive circuit 54 d. The magnet 56 is fixed to the valve seat 51j side tip end portion of the valve body 52. The magnet 56 may be a permanent magnet or an electromagnet that is energized when the drive circuit 54d is operated.

When the spool 52 moves, the magnet 56 also moves integrally therewith. Therefore, when the spool 52 moves, the magnetic field of the hall element 55 and its surroundings changes. A sensor signal corresponding to the magnetic field is input from the hall element 55 to the drive circuit 54 d. The drive circuit 54d can calculate the lift amount of the valve body 52 based on the sensor signal. Therefore, the hall element 55 functions as a gap sensor.

If the expansion valve 5 operates normally, the amount of current supplied from the harnesses Y6 and Y7 to the microvalve Y1 is correlated with the amount of lift of the valve body 52. The drive circuit 54d detects the presence or absence of a failure of the expansion valve 5 based on the information on the lift amount using this.

Specifically, the drive circuit 54d calculates the supply power to be supplied from the harnesses Y6, Y7 to the micro valve Y1, which is necessary to realize the lift amount in a normal state, based on the calculated lift amount and a preset correspondence map. The calculated supply power is referred to as necessary supply power. The corresponding map is recorded in the nonvolatile memory of the drive circuit 54 d. The non-volatile memory is a non-volatile tangible storage medium. The correspondence relationship between the lift amount and the supply power in the correspondence map may be determined in advance through experiments or the like.

Then, the drive circuit 54d compares the calculated necessary supply power with the power actually supplied from the harnesses Y6, Y7 to the micro valve Y1. The drive circuit 54d determines that the expansion valve 5 has failed if the absolute value of the difference between the former electric power and the latter electric power exceeds the allowable value, and determines that the expansion valve 5 is normal if the absolute value does not exceed the allowable value. When determining that the expansion valve 5 has failed, the drive circuit 54d notifies the control device Y55 outside the expansion valve 5 that the expansion valve 5 has failed. In the present embodiment, a signal line is connected from the drive circuit 54d to the control device Y55 so that the drive circuit 54d can notify the control device Y55.

The control device Y55 may be, for example, an air conditioning ECU that controls operations of a compressor, a blower, an air mix door, an inside/outside air switching door, and the like in a vehicle air conditioner. Alternatively, the control device Y55 may be a meter ECU that displays the vehicle speed, the remaining fuel level, the remaining battery level, and the like in the vehicle. When the controller Y55 receives a notification from the drive circuit 54d that the expansion valve 5 has failed, the controller Y55 performs predetermined failure notification control.

The control device Y55 operates the notification device Y56 for notifying the vehicle occupant of the failure notification control. For example, the control device Y55 may turn on a warning lamp. Further, the control device Y55 may cause the image display device to display an image indicating that the expansion valve 5 has failed. Thereby, the occupant of the vehicle can notice the failure of the expansion valve 5.

In the failure report control, the control device Y55 may record information indicating that the expansion valve 5 has failed in a storage device in the vehicle. The storage device is a non-volatile tangible storage medium. This allows the failure of the expansion valve 5 to be recorded outside the expansion valve 5.

When determining that the expansion valve 5 has failed, the drive circuit 54d performs energization stop control. In the energization stop control, the drive circuit 54d stops energization of the expansion valve 5 from the harnesses Y6, Y7. By stopping the energization of the micro valve Y1 at the time of failure of the micro valve Y1 in this way, the safety of the micro valve Y1 at the time of failure can be improved.

As described above, the hall element 55 as the gap sensor outputs the sensor signal for identifying whether or not the microvalve Y1 is operating normally, whereby the drive circuit 54d can easily identify the presence or absence of a failure of the microvalve Y1. Further, the modifications of the present embodiment to the first embodiment can also be applied to fourth to tenth embodiments described later.

(fourth embodiment)

Next, a fourth embodiment will be described with reference to fig. 18 to 26. The members denoted by the same reference numerals in the present embodiment and the first embodiment have the same configurations unless otherwise described below. The refrigeration cycle 1 of the present embodiment differs from the refrigeration cycle 1 of the first embodiment only in the configuration of the expansion valve 5. The compressor 2, the condenser 3, and the receiver 4 have the same configuration as in the first embodiment.

The expansion valve 5 of the present embodiment differs from the expansion valve 5 of the first embodiment in the position and structure of the valve block Y0, the structure of the valve chamber 51g, and the like. Hereinafter, the expansion valve 5 will be mainly described in a portion different from the first embodiment.

As shown in fig. 18, the expansion valve 5 includes a main body 51, a valve body 52, a coil spring 53, a main body 54, a valve assembly Y0, a load adjustment portion 67, and the like.

The purpose and material of the main body 51 are the same as those of the first embodiment. The first inlet 51a, the first outlet 51b, the second inlet 51c, the second inlet 51d, the second outlet 51e, the evaporated refrigerant passage 51f, the valve chamber 51g, and the orifice passage 51h formed in the main body 51 have the same configuration, use, and connection to the outside as those of the first embodiment. However, a back pressure chamber having a pressure different from that of the throttle passage 51h side of the valve chamber 51g is not provided in the valve chamber 51g in which the valve body 52 is accommodated.

Hereinafter, in the expansion valve 5, the arrangement direction of the refrigerant passage 51f after evaporation and the valve body 52 is referred to as a vertical direction, the extending direction of the refrigerant passage 51f after evaporation is referred to as a width direction, and a direction perpendicular to both the vertical direction and the width direction is referred to as a thickness direction. In fig. 18, the vertical direction corresponds to the vertical direction, the horizontal direction corresponds to the width direction, and the vertical direction corresponds to the thickness direction. The outer shape of the expansion valve 5 is long in the order of the longitudinal length, the width-direction length, and the thickness-direction length. This is the same as in the first to third embodiments.

The main unit 54 includes a housing 54a, a circuit board 54b, a composite sensor 54c, and a drive circuit 54d, which are similar to those of the first embodiment.

The coil spring 53 is an elastic body that biases the valve body 52 toward the side where the throttle passage 51h is closed, as in the first embodiment. Specifically, the coil spring 53 is located on the opposite side of the evaporated refrigerant passage 51f with respect to the valve body 52. The end of the coil spring 53 on the valve body 52 side abuts against the valve body 52 to press the valve body 52, and the end on the opposite side to the valve body 52 abuts against the load adjuster 67 to press the load adjuster 67.

The load adjuster 67 is a cap member that closes the valve chamber 51g and separates the valve chamber 51g from the outside space of the body 51. Further, a seal ring 68 is disposed between the load adjuster 67 and the main body 51. The seal ring 68 seals the valve chamber 51g in a liquid-tight manner from the space outside the main body 51.

A thread and a thread groove are formed on the outer periphery surrounding the central axis of the load adjuster 67, and a thread groove are also formed on the portion of the body 51 into which the load adjuster 67 is fitted. Thereby, the load adjusting portion 67 is a male screw, the main body 51 is a female screw, and the load adjusting portion 67 is screwed to the main body 51. Further, the central axis of the load adjuster 67 extends in the longitudinal direction (i.e., the moving direction of the valve body 52) in fig. 18.

An operation receiving portion 67a exposed to the outside space of the main body 51 is formed on the surface of the load adjuster 67 on the side opposite to the valve chamber 51 g. As shown in fig. 21, the operation receiving portion 67a has a shape surrounding the hexagonal prism-shaped hole. The operation receiving portion 67a can receive an operation by an operator or the like for adjusting the elastic force of the coil spring 53 from the outside of the main body 51.

The operation is an operation of inserting a jig such as a hexagonal spine into the hole having the hexagonal prism shape and rotating the jig around the center axis of the load adjustment portion 67. By performing this operation, the load adjusting portion 67 moves in a direction along the central axis while rotating around the central axis as a rotation center. The elastic force of the coil spring 53 is adjusted by the movement of the load adjusting portion 67.

The expansion valve 5 is formed with a communication hole 57 and a housing hole 58 which are not formed in the first embodiment. One end of the communication hole 57 communicates with the post-evaporation refrigerant passage 51f and extends in the longitudinal direction, and the other end communicates with the high-pressure refrigerant passage 51 c. The portion of the communication hole 57 on the high-pressure refrigerant passage 51c side has a smaller flow path cross-sectional area than the portion on the evaporated refrigerant passage 51f side.

One end of the housing hole 58 communicates with the refrigerant passage 51f after evaporation and extends in the longitudinal direction, and the other end communicates with the low-pressure refrigerant passage 51 k.

The expansion valve 5 includes a coil spring 64 and a pressure transmission portion 65. The coil spring 64 is an elastic member whose entire portion is accommodated in the accommodating hole 58, and is movable in the longitudinal direction in the accommodating hole 58. The coil spring 64 biases the pressure transmission portion 65 in the direction of the valve body 52. The portion of the housing hole 58 where the coil spring 64 is disposed is a pressure chamber 58a that generates a control pressure for moving the valve body 52.

A part of the pressure transmitting portion 65 on the coil spring 64 side is accommodated in the accommodating hole 58 and abuts against the coil spring 64. The pressure transmitting portion 65 extends from the portion abutting against the coil spring 64 into the low-pressure refrigerant passage 51k through the communicating portion between the housing hole 58 and the low-pressure refrigerant passage 51 k. Further, the pressure transmitting portion 65 extends from a communicating portion between the low-pressure refrigerant passage 51k and the valve chamber 51g into the valve chamber 51g through the low-pressure refrigerant passage 51 k. Further, the pressure transmission portion 65 abuts on the side of the valve body 52 opposite to the coil spring 53 in the valve chamber 51 g. The pressure transmitting portion 65 is movable in the vertical direction in the housing hole 58.

With such a configuration, the pressure transmission portion 65 receives the control pressure generated in the pressure chamber 58a and the elastic force of the coil spring 64, and transmits a force (i.e., a combined force thereof) corresponding to the control pressure and the elastic force to the valve body 52. Therefore, the spool 52 changes its position in the valve chamber 51g in accordance with the control pressure of the pressure chamber 58a to balance the control pressure of the pressure chamber 58a, the elastic force of the coil spring 64, and the elastic force of the coil spring 53. Then, the opening degree of the orifice passage 51h varies according to the change in the position of the valve body 52.

Further, a seal ring 66 that contacts the outer periphery of the pressure transmitting portion 65 and the inner wall of the housing hole 58 is fixed to the outer periphery of the pressure transmitting portion 65. The seal ring 66 seals between the pressure chamber 58a and the low-pressure refrigerant passage 51k on the outer periphery of the pressure transmission portion 65.

Further, a low-pressure communication passage 58b for guiding the refrigerant in the pressure chamber 58a to the low-pressure refrigerant passage 51k is formed inside the pressure transmission portion 65. One end of the low-pressure communication passage 58b opens into the pressure chamber 58a, and the other end opens into the low-pressure refrigerant passage 51k, whereby the low-pressure communication passage 58b communicates with the low-pressure refrigerant passage 51 k.

Further, a throttle portion 58c is formed between the pressure chamber 58a and the low-pressure refrigerant passage 51k in the low-pressure communication passage 58 b. The throttle portion 58c has a shape in which the flow path cross-sectional area decreases along the low-pressure communication flow path 58 b. That is, the flow path cross-sectional area of the throttle portion 58c is smaller than the flow path cross-sectional areas of the flow paths at both ends thereof. Such a restriction portion 58c can generate a pressure difference between the front and rear thereof. That is, a pressure difference can be generated between the pressure chamber 58a and the low-pressure refrigerant passage 51 k.

Here, the valve assembly Y0 will be described with reference to fig. 18, 19, 20, 22, 23, and 24. The valve assembly Y0 of the present embodiment is disposed between the circuit board 54b and the valve body 52, and includes a micro valve Y1, a valve housing Y2, three O-

rings

62a, 62b, and 62c, 2 harnesses Y6, Y7, and a changeover plate Y8.

The micro valve Y1 of the present embodiment is different from the first embodiment in that the shape of the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 is not circular but rectangular. The microvalve Y1 of the present embodiment differs from the first embodiment in the position where the first refrigerant hole Y16 is formed in the second outer layer Y13. Further, the shape of the beam Y127 and the movable portion Y128 of the microvalve Y1 of the present embodiment is different from that of the first embodiment. The other structure of the microvalve Y1 is the same as that of the first embodiment.

The beam Y127 and the movable portion Y128 are different from those of the first embodiment in that they have a frame shape surrounding the through hole Y120 penetrating through the front surface and the back surface of the intermediate layer Y12 together with the movable portion Y128, as shown in fig. 22, 23, and 24.

The first refrigerant holes Y16 overlap the portions of the through holes Y120 surrounded by the beams Y127 in the stacking direction of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13. The first refrigerant hole Y16 is disposed closer to the arm Y126 than the position equidistant from the movable portion Y128 and the arm Y126. The other structures of the beam Y127 and the movable portion Y128 are the same as those of the first embodiment.

Microvalve Y1 operates in the same manner as the first embodiment. This is because the first refrigerant holes Y16 and the through holes Y120 overlap in the stacking direction of the first outer layer Y11, the intermediate layer Y12, and the second outer layer Y13 regardless of whether the movable portion Y128 is in the non-energization position, the maximum energization position, or the intermediate position. Regardless of the position of the movable portion Y128, the first refrigerant hole Y16 communicates with the through hole Y120 of the refrigerant chamber Y19. The second refrigerant hole Y17 and the third refrigerant hole Y18 are connected and disconnected in the same manner as in the first embodiment.

One ends of the electric wires Y6 and Y7 are connected to the first application point Y129 and the second application point Y130 of the micro valve Y1, respectively, and are connected to the pattern printed on the circuit board 54b through the through holes Y14 and Y15 by the other ends. The driver circuit 54d mounted on the circuit board 54b is connected to the pattern. Thus, electric power can be supplied from the drive circuit 54d to the micro valve Y1 through the harnesses Y6 and Y7. Since a space is present between the microvalve Y1 and the circuit board 54b facing each other, the wirings Y6 and Y7 are easily laid out.

The switching plate Y8 is disposed between the micro valve Y1 and the valve housing Y2 in the same manner as in the first embodiment, and has flow paths Y81, Y82, and Y83 penetrating to the front and back surfaces thereof. The flow paths Y81 and Y82 absorb the difference between the arrangement of the refrigerant holes Y16 and Y17 and the arrangement of the communication holes YV1 and YV 2.

One end of the flow path Y81 communicates with the first refrigerant hole Y16, and the other end communicates with a first communication hole YV1 described later. Therefore, the first refrigerant hole Y16 communicates with the first communication hole YV1 via the flow path Y81. One end of the flow path Y82 communicates with the second refrigerant hole Y17, and the other end communicates with a second communication hole YV2 described later. Therefore, the second refrigerant hole Y17 communicates with the second communication hole YV2 through the flow path Y82. One end of the flow path Y83 communicates with the third refrigerant port Y18, but as shown in fig. 20, the other end of the flow path Y83 is blocked by the valve housing Y2. That is, the third refrigerant hole Y18 is substantially closed.

The valve housing Y2 is a resin housing that accommodates the micro valve Y1 and the changeover plate Y8 and absorbs the difference in linear expansion coefficient between the micro valve Y1 and the main body 51, as in the first embodiment. Further, the valve housing Y2 has a base portion Y20 surrounding the microvalve Y1, and columnar first and second projections Y21 and Y22 projecting from the microvalve Y1. The first protrusion Y21 corresponds to a control pressure pipe, and the second protrusion Y22 corresponds to a low pressure pipe. The base portion Y20, the first protruding portion Y21, and the second protruding portion Y22 may or may not be integrally formed.

The base portion Y20 is disposed between the housing 54a and the main body 51, and is fixed to the fixing portion 63 so as to surround the opening 51t formed in the main body 51. The opening 51t is formed in the main body 51, and penetrates from a space surrounded by the casing 54a to the post-evaporation refrigerant passage 51 f.

The first protrusion Y21 is connected to the base portion Y20 at one end, contacts the switching plate Y8, extends through the opening 51t and the evaporated refrigerant passage 51f, and fits into the receiving hole 58 at the other end. Thus, the first projection Y21 penetrates the refrigerant passage 51f after evaporation from the micro valve Y1 side to the pressure chamber 58a side.

The second protrusion Y22 is connected to the base portion Y20 at one end and contacts the switching plate Y8, extends through the opening 51t and the evaporated refrigerant passage 51f, and is fitted into the communication hole 57 at the other end. Thus, the second protrusion Y22 penetrates the refrigerant passage 51f after evaporation from the micro valve Y1 side to the pressure chamber 58a side. The extending directions of the first protruding portion Y21 and the second protruding portion Y22 intersect both the width direction and the thickness direction. More specifically, the extending direction of the first protrusion Y21 and the second protrusion Y22 is the longitudinal direction.

The first protrusion Y21 and the second protrusion Y22 are arranged in the width direction of the refrigerant passage 51f after evaporation (i.e., the direction in which the refrigerant flows in the refrigerant passage 51f after evaporation). With this arrangement, the pressure loss of the refrigerant in the refrigerant passage 51f after the evaporation is reduced. The first protrusion Y21 and the second protrusion Y22 are integrally connected to each other inside the opening 51 t. Further, O-rings 62c are disposed on the outer peripheries of the first projection Y21 and the second projection Y22 in the opening 51 t. The O-ring 62c seals the space surrounded by the housing 54a and the evaporated refrigerant passage 51f by contacting both the outer peripheries of the first projection Y21 and the second projection Y22 and the inner wall of the opening 51 t.

Further, the O-ring 62a is disposed on the outer periphery of the first projecting portion Y21 in the receiving hole 58. The O-ring 62a seals the space between the evaporated refrigerant passage 51f and the pressure chamber 58a by contacting both the outer periphery of the first projecting portion Y21 and the inner wall of the housing hole 58. Further, an O-ring 62b is disposed on the outer periphery of the second projecting portion Y22 in the communication hole 57. The O-ring 62b seals between the refrigerant passage 51f after evaporation and the high-pressure refrigerant passage 51c by contacting both the outer periphery of the second projecting portion Y22 and the inner wall of the communication hole 57.

In addition, a first communication hole YV1 is formed inside the first protrusion Y21. The first communication hole YV1 corresponds to the control pressure introduction hole. The first communication hole YV1 communicates with the first refrigerant hole Y16 at a position closer to the microvalve Y1 than the refrigerant passage 51f after evaporation, and communicates with the pressure chamber 58a at a position closer to the pressure chamber 58a than the refrigerant passage 51f after evaporation. As described above, by forming the first communication hole YV1 in the first protrusion Y21 that penetrates the refrigerant passage 51f after evaporation, interference between the refrigerant introduced into the pressure chamber 58a and the refrigerant flowing through the refrigerant passage 51f after evaporation can be prevented while suppressing the body shape of the main body 51 in the thickness direction.

In addition, a second communication hole YV2 is formed inside the second protrusion Y22. The second communication hole YV2 corresponds to a high-pressure introduction hole. The second communication hole YV2 communicates with the second refrigerant hole Y17 at a position closer to the microvalve Y1 than the refrigerant passage 51f after evaporation, and communicates with the high-pressure refrigerant passage 51c through the communication hole 57 at a position closer to the high-pressure refrigerant passage 51c than the refrigerant passage 51f after evaporation. By forming the second communication hole YV2 in the second projection Y22 that penetrates the refrigerant passage 51f after evaporation in this manner, interference between the high-pressure refrigerant and the low-pressure refrigerant flowing through the refrigerant passage 51f after evaporation can be prevented while suppressing the body shape of the main body 51 in the thickness direction.

By configuring the expansion valve 5 as described above, the circuit board 54b, the micro valve Y1, the first protruding portion Y21, the pressure chamber 58a, the pressure transmitting portion 65, the valve body 52, the coil spring 53, and the load adjusting portion 67 are sequentially aligned in a line in the vertical direction. Further, the micro valve Y1, the refrigerant passage 51f after evaporation, the pressure chamber 58a, the low-pressure refrigerant passage 51k, and the valve chamber 51g are also sequentially aligned in a row in the vertical direction.

The operation of the refrigeration cycle 1 having such a configuration will be described below mainly focusing on differences from the first embodiment. The third refrigerant hole Y18 does not allow the through hole Y120 to communicate with another refrigerant flow path regardless of whether it is open or not. Since the first refrigerant hole Y16 is always open regardless of the position of the movable portion Y128, the through hole Y120 of the micro valve Y1 is always in communication with the storage hole 58 via the first communication hole YV 1.

[ non-operation ]

First, the non-operation of the refrigeration cycle will be described. In this case, the operation and non-operation of each device of the refrigeration cycle 1 and the energization and non-energization are the same as those of the first embodiment. In this case, the second communication hole YV2 is cut off from the through hole Y120 of the micro valve Y1.

In this case, as in the first embodiment, the pressure of the refrigerant between the receiver 4 and the expansion valve 5 and the pressure of the refrigerant between the expansion valve 5 and the evaporator 6 are equal to each other. Therefore, the pressure of the refrigerant in the high-pressure refrigerant passage 51c and the pressure of the refrigerant in the low-pressure refrigerant passage 51k are also equal to each other.

Since the low-pressure refrigerant passage 51k and the housing hole 58 are in communication with each other for a long time through the low-pressure communication passage 58b, the pressure of the housing hole 58 is equal to the pressure of the low-pressure refrigerant passage 51 k. The pressure in the valve chamber 51g is the same as the pressure in the low-pressure refrigerant passage 51 k. Therefore, due to the balance between the elastic force of the coil spring 53 and the elastic force of the coil spring 64, as shown in fig. 26, the valve body 52 contacts the valve seat 51j, and the orifice passage 51h is closed.

[ operation ]

Next, a state in which the refrigeration cycle is operating will be described. In this case, the compressor 2 and the blower 8 are operated. Thereby, the pressure of the refrigerant in the high-pressure refrigerant passage 51c is higher than the pressure of the refrigerant in the low-pressure refrigerant passage 51 k. The composite sensor 54c and the drive circuit 54d also operate. Therefore, the micro valve Y1 is energized from the drive circuit 54d via the harnesses Y6, Y7 as necessary.

Specifically, the drive circuit 54d increases the duty ratio as the pressure indicated by the pressure signal is constant and the temperature indicated by the temperature signal is higher, that is, as the degree of superheat is higher. This increases the lift amount of the valve body 52, and decreases the superheat degree. The drive circuit 54d decreases the duty ratio as the temperature indicated by the temperature signal is constant and the pressure indicated by the pressure signal is higher, that is, the degree of superheat is lower. This reduces the amount of lift of the valve body 52, and increases the degree of superheat.

For example, when the duty ratio is increased to 100%, the second communication hole YV2 and the first communication hole YV1 communicate with each other through the micro valve Y1. Therefore, the high-pressure refrigerant in the high-pressure refrigerant passage 51c is introduced into the micro valve Y1 via the communication hole 57, the second communication hole YV2, the flow path Y82, and the second refrigerant hole Y17. The high-pressure refrigerant is supplied from the first refrigerant hole Y16 of the micro valve Y1 to the pressure chamber 58a through the flow path Y81 and the first communication hole YV 1.

Accordingly, the pressure in the pressure chamber 58a becomes high, and the force transmitted to the valve body 52 via the pressure transmission portion 65 becomes maximum. As a result, as shown in fig. 25, the opening degree and the lift amount of the orifice passage 51h become the maximum. Further, the pressure chamber 58a and the low-pressure refrigerant passage 51k communicate with each other via the low-pressure communication passage 58b, but since the throttle portion 58c is formed in the low-pressure communication passage 58b, the pressure difference between the pressure chamber 58a and the low-pressure refrigerant passage 51k is maintained.

For example, when the duty ratio is larger than zero and smaller than 100%, the second communication hole YV2 and the first communication hole YV1 communicate with each other through the micro valve Y1. However, the opening degree of the second refrigerant hole Y17 is smaller than that at the duty ratio of 100%, and the opening degree of the second refrigerant hole Y17 is larger as the duty ratio is larger. Therefore, the pressure in the through hole Y120 of the micro valve Y1 is lower as the duty ratio is smaller due to the pressure reduction effect of the first refrigerant hole Y16.

Therefore, the smaller the duty ratio, the lower the refrigerant pressure output from the first refrigerant hole Y16 of the microvalve Y1 to the pressure chamber 58a via the first communication hole YV 1. Thereby, the force transmitted to the valve body 52 via the pressure transmission portion 65 becomes a value smaller than the maximum value and larger than the minimum value. The opening degree and the lift amount of the orifice passage 51h are smaller as the duty ratio is smaller in a range of larger than the minimum and smaller than the maximum.

In addition, for example, when the duty ratio is reduced to 0%, the second refrigerant hole Y17 is blocked. Then, the flow of the refrigerant from the high-pressure refrigerant passage 51c to the through hole Y120 in the microvalve Y1 is shut off. Then, the refrigerant in the pressure chamber 58a gradually flows out to the low-pressure refrigerant passage 51k through the low-pressure communication passage 58b, and the pressure of the refrigerant in the pressure chamber 58a decreases. Finally, the pressure of the refrigerant in the pressure chamber 58a is the same as the pressure of the low-pressure refrigerant passage 51 k. Therefore, the force transmitted from the pressure transmission portion 65 to the valve body 52 also gradually decreases, whereby the lift amount and the opening degree of the orifice passage 51h decrease, and finally become zero as shown in fig. 26.

Further, as described above, when the duty ratio is larger than 0 and the lift amount of the valve element 52 is larger than zero while the refrigeration cycle 1 is operating, a pressure difference is generated between the pressure chamber 58a and the low-pressure refrigerant passage 51 k. At this time, the refrigerant flows from the high-pressure refrigerant passage 51c to the low-pressure refrigerant passage 51k through the communication hole 57, the second communication hole YV2, the second refrigerant hole Y17, the through hole Y120, the first refrigerant hole Y16, the first communication hole YV1, the pressure chamber 58a, and the low-pressure communication flow path 58b in this order. At this time, as described above, the pressure difference between the pressure chamber 58a and the low-pressure refrigerant passage 51k continues to exist due to the pressure reducing action of the throttle portion 58 c. However, the flow rate of the refrigerant is much smaller than the flow rate of the refrigerant flowing from the high-pressure refrigerant passage 51c to the low-pressure refrigerant passage 51k through the valve chamber 51 g.

Thus, the low-pressure communication passage 58b guides the refrigerant flowing out of the microvalve Y1 to the high-pressure refrigerant passage 51 c. Thereby, the refrigerant guided from the low-pressure communication passage 58b to the low-pressure refrigerant passage 51k flows into the evaporator 6. Therefore, the refrigerant that does not contribute to heat exchange can be reduced as compared with the case where the refrigerant guided to the low-pressure side from the first refrigerant hole Y16 does not flow into the evaporator 6. Further, the possibility of wasteful use of the refrigerant is reduced, and the efficiency of the refrigeration cycle 1 is improved.

The first refrigerant hole Y16 outputs a control pressure higher than the low pressure of the low-pressure refrigerant passage 51k to the pressure chamber 58a, and the low-pressure communication passage 58b guides the refrigerant flowing out of the first refrigerant hole Y16 to the low-pressure refrigerant passage 51 k. The low-pressure communication flow path 58b is provided with a throttle portion 58c whose flow path cross-sectional area decreases along the low-pressure communication flow path 58 b.

In this way, the low-pressure communication flow path 58b is configured to guide the refrigerant flowing out of the first refrigerant hole Y16 to the low-pressure refrigerant passage 51k, so that it is not necessary to communicate the third refrigerant hole Y18 of the micro valve Y1 with the low-pressure communication flow path. In addition, in such a configuration, since the throttle portion 58c is formed in the low-pressure communication flow passage 58b, a pressure difference can be generated between the front and rear of the throttle portion 58c, and therefore, the possibility of the function of the first refrigerant hole Y16, such as the output control pressure, being impaired is reduced.

The pressure transmission portion 65 extends from the pressure chamber 58a to the valve body 52 through the low-pressure refrigerant passage 51k, and the low-pressure communication passage 58b is formed inside the pressure transmission portion 65 and communicates from the pressure chamber 58a to the low-pressure refrigerant passage 51 k. In this way, the low-pressure communication passage 58b that communicates from the pressure chamber 58a to the low-pressure refrigerant passage 51k is formed by the pressure transmitting portion 65 receiving the control pressure of the pressure chamber 58a and passing through the low-pressure refrigerant passage 51k, so that it is not necessary to provide a member only for the low-pressure communication passage 58 b.

The combination sensor 54c, the micro valve Y1, and the drive circuit 54d are disposed on the side opposite to the valve body 52 with respect to the evaporated refrigerant passage 51 f. With this configuration, the arrangement of the electric wiring among the sensor, the control valve member, and the drive circuit is facilitated.

Further, in the main body 51, the micro valve Y1, the refrigerant passage 51f after evaporation, and the pressure chamber 58a are arranged in a row in the vertical direction in this order. The first projection Y21 serving as a control pressure pipe penetrates the refrigerant passage 51f after evaporation from the microvalve Y1 side to the pressure chamber 58a side. Further, a first communication hole YV1 is formed in the first protrusion Y21, and the first communication hole YV1 communicates with the first refrigerant hole Y16 at a position closer to the micro valve Y1 than the refrigerant passage 51f after evaporation, and communicates with the pressure chamber 58a at a position closer to the pressure chamber 58a than the refrigerant passage 51f after evaporation.

With such a configuration, the control pressure can be applied from the micro valve Y1 via the first communication hole YV1 formed at the first protrusion Y21 penetrating the post-evaporation refrigerant passage 51 f. Therefore, while maintaining the function of the micro valve Y1, the layout of the electric wiring among the composite sensor 54c, the micro valve Y1, and the drive circuit 54d is facilitated. Further, the size of the microvalve Y1 and the valve device in the thickness direction can be suppressed.

(fifth embodiment)

Next, a fifth embodiment will be described with reference to fig. 27 and 28. The refrigeration cycle 1 according to the present embodiment is arranged with the low-pressure communication flow passage 58b being changed from the refrigeration cycle 1 according to the fourth embodiment. The other structure is the same as that of the fourth embodiment.

The low-pressure communication flow path 58b of the present embodiment is not formed inside the pressure transmission portion 65, but is disposed in the form of a gap between the outer peripheral surface of the pressure transmission portion 65 and the inner peripheral surface of the housing hole 58. The low-pressure communication passage 58b communicates with the pressure chamber 58a at one end and communicates with the low-pressure refrigerant passage 51k at the other end.

Further, as shown in fig. 28, a slit 66a through which the refrigerant can pass is formed in the seal ring 66 in order to communicate the low-pressure communication passage 58b with both the pressure chamber 58a and the low-pressure refrigerant passage 51 k. The slit 66a penetrates in the longitudinal direction (i.e., the direction perpendicular to the paper surface of fig. 28). The slit 66a is a part of the low-pressure communication passage 58b, and has a passage cross-sectional area smaller than that of the other part of the slit 66 a. Therefore, the slit 66a functions as a throttle portion that generates a pressure difference between the pressure chamber 58a and the low-pressure refrigerant passage 51 k.

The operation of the refrigeration cycle 1 in the present embodiment is an operation in which the low-pressure communication flow passage 58b and the slit 66a in the fourth embodiment are replaced with the low-pressure communication flow passage 58b and the slit 66a in the present embodiment.

As described above, when the housing hole 58 includes the pressure chamber 58a and communicates with the low-pressure refrigerant passage 51k, or when the pressure transmission portion 65 receives the control pressure of the pressure chamber 58a and passes through the low-pressure refrigerant passage 51k, the low-pressure communication flow path 58b can be provided in the gap between the inner wall surface of the housing hole 58 and the outer peripheral surface of the pressure transmission portion 65. By so doing, it is not necessary to provide a member only for the low-pressure communication flow passage 58 b. Further, since the seal ring 66 can be used as the throttle portion, it is not necessary to complicate the shapes of the main body 51 and the pressure transmission portion 65 in order to provide the throttle portion. In the present embodiment, the same effects as those of the fourth embodiment can be obtained from the same configuration as those of the fourth embodiment.

(sixth embodiment)

Next, a sixth embodiment will be described with reference to fig. 29. The refrigeration cycle 1 according to the present embodiment is arranged with the low-pressure communication flow passage 58b being changed from the refrigeration cycle 1 according to the fourth embodiment. The other structure is the same as that of the fourth embodiment.

The low-pressure communication passage 58b of the present embodiment is not formed inside the pressure transmission portion 65, but is formed in the main body 51 so as to communicate with the low-pressure refrigerant passage 51k by bypassing the pressure transmission portion 65 from the pressure chamber 58 a. The low-pressure communication passage 58b branches from the housing hole 58 in the pressure chamber 58a, and extends to the low-pressure refrigerant passage 51k in the main body 51.

Further, in the low-pressure communication passage 58b, a throttle portion 58c having a smaller passage cross-sectional area than the passage cross-sectional areas before and after is formed between the pressure chamber 58a and the low-pressure refrigerant passage 51k, as in the fourth embodiment. Such a pressure difference can be generated between the front and rear of the throttle portion 58c by the throttle portion 58 c. That is, a pressure difference can be generated between the pressure chamber 58a and the low-pressure refrigerant passage 51 k. In the present embodiment, the same effects as those of the fourth embodiment can be obtained from the same configuration as those of the fourth embodiment.

(seventh embodiment)

Next, a seventh embodiment will be described with reference to fig. 30. The refrigeration cycle 1 according to the present embodiment differs from the refrigeration cycle 1 according to the fourth embodiment in the configuration of the valve housing Y2, the configuration of the changeover plate Y8, the arrangement of the low-pressure communication flow passage, and the structure of the main body 51. The other structure is the same as that of the fourth embodiment. The following description focuses on differences from the fourth embodiment.

The valve housing Y2 of the present embodiment includes a third projecting portion Y23 in addition to the base portion Y20, the first projecting portion Y21, the second projecting portion Y22, and the O-

rings

62a, 62b, and 62c, which are similar to those of the fourth embodiment. The third projection Y23 corresponds to a low pressure tube. The base portion Y20, the first protruding portion Y21, the second protruding portion Y22, and the third protruding portion Y23 may or may not be integrally formed.

The third protrusion Y23 is connected to the base portion Y20 at one end and contacts the switching plate Y8, extends through the opening 51t and the post-evaporation refrigerant passage 51f, and is fitted into the communication hole 59 at the other end. The communication hole 59 is a hole formed in the main body 51 in the present embodiment, and has one end communicating with the post-evaporation refrigerant passage 51f and the other end communicating with the low-pressure refrigerant passage 51 k.

Thus, the third projection Y23 penetrates the refrigerant passage 51f after evaporation from the micro valve Y1 side to the pressure chamber 58a and the low-pressure refrigerant passage 51k side. The extending direction of the third projecting portion Y23 intersects both the width direction and the thickness direction, more specifically, the longitudinal direction. The first projection Y21, the second projection Y22, and the third projection Y23 are arranged in the width direction of the refrigerant passage 51f after evaporation (i.e., the direction in which the refrigerant flows in the refrigerant passage 51f after evaporation). With this arrangement, the pressure loss of the refrigerant in the refrigerant passage 51f after the evaporation is reduced.

The first projection Y21, the second projection Y22, and the third projection Y23 are integrally connected to each other inside the opening 51 t. Further, O-rings 62c similar to those of the fourth embodiment are disposed on the outer peripheries of the first projection Y21, the second projection Y22, and the third projection Y23 in the opening 51 t.

Further, an O-ring 62d is disposed on the outer periphery of the third projection Y23 in the communication hole 59. The O-ring 62d seals the space between the evaporated refrigerant passage 51f and the low-pressure refrigerant passage 51k by contacting both the outer periphery of the third projection Y23 and the inner wall of the communication hole 59.

Further, a third communication hole YV3 is formed inside the third protrusion Y23. The third communication hole YV3 corresponds to a low pressure introduction hole. The third communication hole YV3 communicates with the third refrigerant hole Y18 at a position closer to the microvalve Y1 than the refrigerant passage 51f after evaporation, and communicates with the low-pressure refrigerant passage 51k through the communication hole 59 at a position closer to the low-pressure refrigerant passage 51k than the refrigerant passage 51f after evaporation. By forming the third communication hole YV3 in the third projection Y23 that penetrates the refrigerant passage 51f after evaporation in this manner, the refrigerant in the refrigerant passage 51f after evaporation and the refrigerant in the low-pressure refrigerant passage 51k can be less likely to mix, while the body shape of the main body 51 in the thickness direction is suppressed. In the present embodiment, the third communication hole YV3 corresponds to a low-pressure communication flow path.

In the present embodiment, the flow path Y83 of the switching plate Y8 communicates with the third refrigerant hole Y18 at one end and with the third communication hole YV3 at the other end. Thereby, the third communication hole YV3 and the third refrigerant hole Y18 are communicated with each other. Therefore, the connection relationship of the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 to the first communication hole YV1, the second communication hole YV2, and the third communication hole YV3 is the same as that of the first embodiment.

The microvalve Y1 of the present embodiment may be the same microvalve Y1 as in the fourth embodiment, or may be the same microvalve Y1 as in the first embodiment. In either case, the displacement of the movable portion Y128 of the microvalve Y1 amplified by the amplifying portion (i.e., the arm Y126 and the beam Y127) is transmitted and moves in the refrigerant chamber Y19. By this movement, the opening degrees of the second refrigerant hole Y17 and the third refrigerant hole Y18 with respect to the through hole Y120 can be adjusted.

In the pressure transmission portion 65 of the present embodiment, the low-pressure communication passage 58b is not formed. Therefore, the pressure chamber 58a of the present embodiment does not communicate with the high-pressure refrigerant passage 51c and the low-pressure refrigerant passage 51k in the expansion valve 5 without passing through the micro valve Y1.

The operation of the refrigeration cycle 1 having such a configuration will be described below.

[ non-operation ]

First, the non-operation of the refrigeration cycle will be described. In this case, the operation and non-operation of each device of the refrigeration cycle 1 and the energization and non-energization are the same as those of the first embodiment. Therefore, in this case, the third communication hole YV3 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the second communication hole YV2 and the through hole Y120 of the micro valve Y1 are cut off from each other.

In this case, as in the first embodiment, the pressure of the refrigerant between the receiver 4 and the expansion valve 5 and the pressure of the refrigerant between the expansion valve 5 and the evaporator 6 are equal to each other. Therefore, the pressure of the refrigerant in the high-pressure refrigerant passage 51c and the pressure of the refrigerant in the low-pressure refrigerant passage 51k are also equal to each other. The pressure in the valve chamber 51g is the same as the pressure in the low-pressure refrigerant passage 51 k. Therefore, the valve body 52 contacts the valve seat 51j due to the balance between the elastic force of the coil spring 53 and the elastic force of the coil spring 64, and the orifice passage 51h is closed.

[ operation ]

Next, a state in which the refrigeration cycle is operating will be described. In this case, the compressor 2 and the blower 8 are operated. Thereby, the pressure of the refrigerant in the high-pressure refrigerant passage 51c is higher than the pressure of the refrigerant in the low-pressure refrigerant passage 51 k. The composite sensor 54c and the drive circuit 54d also operate. Therefore, the micro valve Y1 is energized from the drive circuit 54d via the harnesses Y6, Y7 as necessary. At this time, by the operation similar to that of the fourth embodiment, the drive circuit 54d determines the duty ratio of the voltage applied to the harnesses Y6, Y7 so that the degree of superheat of the low-pressure refrigerant flowing out of the evaporator 6 becomes a predetermined constant value, based on the acquired pressure signal and temperature signal.

For example, when the duty ratio is 100%, the second communication hole YV2 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the third communication hole YV3 and the through hole Y120 of the micro valve Y1 are cut off, as in the first embodiment. Therefore, the high-pressure refrigerant in the high-pressure refrigerant passage 51c is introduced into the micro valve Y1 via the communication hole 57, the second communication hole YV2, the flow path Y82, and the second refrigerant hole Y17. The high-pressure refrigerant is supplied from the first refrigerant hole Y16 of the micro valve Y1 to the pressure chamber 58a through the flow path Y81 and the first communication hole YV 1. Accordingly, the pressure in the pressure chamber 58a becomes high, and the force transmitted to the valve body 52 via the pressure transmission portion 65 becomes maximum. As a result, the opening degree and the lift amount of the orifice passage 51h become the maximum.

For example, when the duty ratio is larger than zero and smaller than 100%, the second communication hole YV2 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the third communication hole YV3 and the first communication hole YV1 communicate with each other through the micro valve Y1, as in the first embodiment. At this time, the control pressure output from the first refrigerant hole Y16 of the micro valve Y1 to the pressure chamber 58a is lower than the high pressure in the high-pressure refrigerant passage 51c and higher than the low pressure in the low-pressure refrigerant passage 51 k. The smaller the duty ratio, the smaller the opening degree of the second refrigerant hole Y17 and the larger the opening degree of the third refrigerant hole Y18. Therefore, the control pressure output from the first refrigerant port Y16 of the micro valve Y1 to the pressure chamber 58a decreases as the duty ratio decreases due to the pressure reducing action of the second refrigerant port Y17 and the third refrigerant port Y18.

Thereby, the force transmitted to the valve body 52 via the pressure transmission portion 65 becomes a value smaller than the maximum value and larger than the minimum value. The opening degree and the lift amount of the orifice passage 51h are smaller as the duty ratio is smaller in a range of larger than the minimum and smaller than the maximum. When the duty ratio is greater than zero and less than 100%, the refrigerant flows from the high-pressure refrigerant passage 51c to the low-pressure refrigerant passage 51k through the second communication hole YV2, the micro valve Y1, and the third communication hole YV3 in this order. However, the flow amount is much smaller than the amount flowing from the high-pressure refrigerant passage 51c to the low-pressure refrigerant passage 51k through the valve chamber 51 g.

For example, when the duty ratio is zero, the third communication hole YV3 and the first communication hole YV1 communicate with each other through the micro valve Y1, and the second communication hole YV2 and the through hole Y120 of the micro valve Y1 are cut off, as in the first embodiment. Therefore, the low-pressure refrigerant in the low-pressure refrigerant passage 51k is introduced into the micro valve Y1 through the communication hole 59, the third communication hole YV3, the flow path Y83, and the third refrigerant hole Y18. The low-pressure refrigerant is supplied from the first refrigerant hole Y16 of the micro valve Y1 to the pressure chamber 58a through the flow path Y81 and the first communication hole YV 1. Thereby, the pressure in the pressure chamber 58a becomes low, the valve body 52 contacts the valve seat 51j, and the orifice passage 51h is closed.

The third communication hole YV3 corresponding to the pressure communication flow path passes through the evaporated refrigerant passage 51f from the third refrigerant hole Y18 and communicates with the low-pressure refrigerant passage 51 k. In the present embodiment, as in the fourth embodiment, a load adjusting portion 67 is provided which is capable of receiving an operation for adjusting the spring force of the coil spring 53 from the outside of the main body 51 and is located on the same side as the valve body 52 with respect to the refrigerant passage 51f after evaporation. The microvalve Y1 is located on the opposite side of the load adjuster 67, the valve body 52, and the low-pressure refrigerant passage 51k with respect to the evaporated refrigerant passage 51f so as to avoid interference with the load adjuster 67. In this case, the third communication hole YV3 passes from the third refrigerant hole Y18 over the evaporated refrigerant passage 51f to communicate with the low-pressure refrigerant passage 51k, whereby the refrigerant can be guided from the micro valve Y1 to the low-pressure refrigerant passage 51k while avoiding interference between the micro valve Y1 and the load adjuster 67.

Further, a third communication hole YV3 as a low-pressure communication flow path is formed in the third projection Y23 that penetrates the evaporated refrigerant passage 51f from the microvalve Y1 side to the low-pressure refrigerant passage 51k side. With this configuration, even if the refrigerant passage 51f after evaporation intersects the third communication hole YV3, both passages are insulated from each other. Further, the size of the expansion valve 5 in the thickness direction intersecting the direction in which the evaporated refrigerant passage 51f, the pressure chamber 58a, the pressure transmission portion 65, and the valve body 52 are arranged and the direction in which the evaporated refrigerant passage 51f extends can be suppressed. In the present embodiment, the same effects as those of the fourth embodiment can be obtained from the same configuration as those of the fourth embodiment.

(eighth embodiment)

Next, an eighth embodiment will be described with reference to fig. 31 and 32. The refrigeration cycle 1 of the present embodiment differs from the seventh embodiment in the configuration of the valve housing Y2, the configuration of the switching plate Y8, the arrangement of the low-pressure communication flow passage, and the structure of the main body 51. The other structure is the same as that of the seventh embodiment. The following description focuses on differences from the fourth embodiment.

The valve housing Y2 of the present embodiment differs in the position and length of the third projection Y23 from the valve housing Y2 of the seventh embodiment. Specifically, as shown in fig. 32, the third protrusion Y23 is arranged in line with the second protrusion Y22 in the thickness direction of the expansion valve 5. The third projecting portion Y23 of the present embodiment has a shorter longitudinal length than that of the seventh embodiment. In addition, the length of the third communication hole YV3 formed in the third protrusion Y23 also becomes shorter as the third protrusion Y23 becomes shorter.

One end of the third communication hole YV3 communicates with the flow path Y83 of the switch plate Y8, and the other end communicates with the bypass flow path 58 d. As shown in fig. 32, the bypass passage 58d is formed in the main body 51, communicates with the third communication hole YV3 at one end, extends in the longitudinal direction, extends in the thickness direction, and communicates with the low-pressure refrigerant passage 51k at the other end. Further, a seal member 62e for sealing between the bypass passage 58d and the space outside the main body 51 is attached to the main body 51. The flow path formed by the third communication hole YV3 and the bypass flow path 58d corresponds to a low-pressure communication flow path.

The low-pressure communication passage bypasses the evaporated refrigerant passage 51f from the passage Y83 in the valve housing Y2 and the main body 51 and communicates with the low-pressure refrigerant passage 51 k. That is, the low-pressure communication hole flow path passes through a position shifted in the thickness direction of the main body 51 with respect to the post-evaporation refrigerant passage 51f, and extends from a position closer to the microvalve Y1 than to the post-evaporation refrigerant passage 51f to a position closer to the low-pressure refrigerant passage 51k than to the post-evaporation refrigerant passage 51f beyond the post-evaporation refrigerant passage.

In the switching plate Y8, flow paths Y81, Y82, and Y83 are formed in the micro valve Y1 such that the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18 communicate with the first communication hole YV1, the second communication hole YV2, and the third communication hole YV3, respectively. This is the same as the seventh embodiment. In the present embodiment, the communication hole 59 is not formed.

The operation of this embodiment is the same as that of the seventh embodiment. However, when the third refrigerant hole Y18 is opened, the refrigeration cycle 1 and the low-pressure refrigerant passage 51k communicate with each other through the third refrigerant hole Y18, the third communication hole YV3, and the bypass flow path 58 d.

Thus, the low-pressure communication passage is formed outside the post-evaporation refrigerant passage 51f in the main body 51 and the valve housing Y2, and the low-pressure communication passage bypasses the post-evaporation refrigerant passage 51f from the third refrigerant hole Y18 side to communicate with the post-evaporation refrigerant passage 51 f. With this configuration, the refrigerant that has come out of the third refrigerant hole Y18 can be guided to the low-pressure refrigerant passage 51k across the post-evaporation refrigerant passage 51f by utilizing the inside of the body 51 in the thickness direction or the like. In the present embodiment, the same effects as those of the seventh embodiment can be obtained from the same configuration as those of the seventh embodiment.

(ninth embodiment)

Next, a ninth embodiment will be described with reference to fig. 33, 34, and 35. In the present embodiment, as compared to the eighth embodiment, as shown in fig. 35, the position at which the third refrigerant hole Y18 communicates is changed from the low-pressure refrigerant passage 51k to the post-evaporation refrigerant passage 51 f.

Specifically, the bypass channel 58d of the eighth embodiment is discarded, and the end of the third communication hole YV3 on the opposite side of the channel Y83 communicates with the refrigerant passage 51f after evaporation. In the operation of the refrigeration cycle 1, the low-pressure refrigerant passage 51k and the evaporated refrigerant passage 51f are at substantially the same pressure, and therefore the same operation as that of the eighth embodiment is also achieved in the present embodiment. In the present embodiment, the same effects as those of the fourth embodiment can be obtained from the same configuration as those of the eighth embodiment.

(tenth embodiment)

Next, a tenth embodiment will be described with reference to fig. 36. The present embodiment differs from the fourth embodiment in the arrangement of the composite sensor 54 c. Specifically, the composite sensor 54c is formed integrally with the valve assembly Y0.

More specifically, the composite sensor 54c is sandwiched between the first projection Y21 and the second projection Y22 in the opening 51t, and is connected to the drive circuit 54d mounted on the circuit board 54b via a wiring not shown.

The composite sensor 54c is attached to both the first protruding portion Y21 and the second protruding portion Y22 by bonding or the like. Thereby, the space surrounded by the case 54a and the refrigerant passage 51f after evaporation are sealed between the composite sensor 54c and the first protrusion Y21 and between the composite sensor 54c and the second protrusion Y22.

As described above, the composite sensor 54c and the valve assembly Y0 are assembled to the main body 51 as one body. By configuring in this manner, the labor for assembly work and the components used for assembly can be reduced as compared with the case where the composite sensor 54c and the micro valve Y1 are assembled as separate bodies to the main body 51. In fact, in the above-described configuration, a member for assembling the composite sensor 54c to the main body 51 is not necessary. Further, it is not necessary to provide a hole for exposing the composite sensor 54c to the evaporated refrigerant passage 51f in the region other than the opening 51 r.

Further, the modification of the present embodiment to the fourth embodiment can be similarly applied to the other embodiments. In addition, in the present embodiment, the same effects as those of the fourth embodiment can be obtained from the same configuration as that of the application target embodiment.

(other embodiments)

The present invention is not limited to the above-described embodiments, and can be modified as appropriate. The above embodiments are not independent of each other, and can be combined appropriately except for the case where it is clear that the combination is not possible. In the above embodiments, elements constituting the embodiments are not necessarily essential, except for cases where the elements are specifically and explicitly indicated as essential, cases where the elements are clearly regarded as essential in principle, and the like. In the above embodiments, when numerical values such as the number, numerical value, amount, and range of the constituent elements of the embodiments are mentioned, the number is not limited to a specific number unless it is specifically stated to be necessary or it is clearly limited to a specific number in principle. In the above-described embodiment, when it is described that the external environment information (for example, the humidity outside the vehicle) of the vehicle is acquired from the sensor, the sensor may be discarded, and the external environment information may be received from a server or cloud outside the vehicle. Alternatively, the sensor may be discarded, the related information related to the external environment information may be acquired from a server or cloud outside the vehicle, and the external environment information may be estimated from the acquired related information. In particular, when a plurality of values are illustrated for a certain amount, values between these plurality of values can be adopted, except for cases where they are described separately and where they are obviously impossible in principle. In the above embodiments, when referring to the shape, positional relationship, and the like of the constituent elements and the like, the shape, positional relationship, and the like are not limited to those unless otherwise stated or unless the principle is limited to a specific shape, positional relationship, and the like. The present invention also allows the following modifications and equivalent ranges to the above embodiments. In addition, the following modifications can independently select application and non-application to the above-described embodiment. That is, any combination of the following modifications can be applied to the above embodiments.

(modification 1)

In each of the above embodiments, the plurality of first ribs Y123 and the plurality of second ribs Y124 generate heat by energization, and their own temperature rises due to the heat generation, thereby expanding. However, these components may also be constructed of shape memory materials that change in length when temperature changes.

(modification 2)

In the fifth embodiment, when the energization of the micro valve Y1 from the harnesses Y6 and Y7 is stopped, the micro valve Y1 communicates with the low-pressure refrigerant passage 51 k. However, this need not necessarily be the case. For example, when the energization of the micro valve Y1 from the harnesses Y6 and Y7 is stopped, the micro valve Y1 may communicate with the high-pressure refrigerant passage 51 c.

(modification 3)

In the third embodiment, the hall element 55 is used as the gap sensor, but an eddy current type sensor may be used as the gap sensor. In this case, the magnet 56 is discarded and the hall element 55 is replaced with a coil, as opposed to the third embodiment. A high-frequency current flows through the coil. As a result, a high-frequency magnetic field is generated around the coil. When the position of the metallic valve body 52 in the magnetic field changes, the impedance of the coil changes. The drive circuit 54d can calculate the lift amount of the valve element 52 based on the conversion of the impedance.

(modification 4)

The function of detecting a failure of the expansion valve 5 by the hall element 55, the magnet 56, and the drive circuit 54d using these elements in the third embodiment can also be applied to the second embodiment. In this case, the drive circuit 54d can simultaneously detect the failure of the expansion valve 5 and the failure of the microvalve Y1. The notification device Y56 can notify both of the failure of the expansion valve 5 and the failure of the micro valve Y1.

(modification 5)

In each of the above embodiments, the second refrigerant hole Y17 communicates with the high-pressure refrigerant passage 51c via the second communication hole YV2 and the high-pressure introduction passage 51P. However, the second refrigerant hole Y17 may communicate with a high-pressure flow path outside the main body 51, instead of the high-pressure refrigerant passage 51 c. In this case, the first passage corresponds to the external high-pressure flow passage, not the high-pressure refrigerant passage 51 c. The external high-pressure flow path may be, for example, a flow path downstream of the receiver 4 in the refrigerant flow direction and upstream of the expansion valve 5 in the refrigerant flow direction.

(modification 6)

In each of the above embodiments, the third refrigerant hole Y18 communicates with the low-pressure refrigerant passage 51k through the third communication hole YV3 and the low-pressure introduction passage 51 q. However, the third refrigerant hole Y18 may communicate with a low-pressure flow path outside the main body 51 instead of the low-pressure refrigerant passage 51 k. In this case, the second passage corresponds to the external low-pressure flow passage, not the low-pressure refrigerant passage 51 k. The external low-pressure flow path may be, for example, a flow path downstream of the expansion valve 5 in the refrigerant flow direction and upstream of the evaporator 6 in the refrigerant flow direction.

(modification 7)

In each of the above embodiments, the movable portion Y128 moves to adjust both the opening degree of the second refrigerant hole Y17 with respect to the through hole Y120 and the opening degree of the third refrigerant hole Y18 with respect to the through hole Y120 in an interlocking manner. However, this need not necessarily be the case.

For example, the movable portion Y128 may be moved to adjust only the opening degree of the second refrigerant hole Y17 with respect to the through hole Y120, and the opening degree of the third refrigerant hole Y18 with respect to the through hole Y120 may be always constant. Alternatively, for example, the movable portion Y128 may be moved to adjust only the opening degree of the third refrigerant hole Y18 with respect to the through hole Y120, and the opening degree of the second refrigerant hole Y17 with respect to the through hole Y120 may be always constant. Even when the movable portion Y128 moves in this manner, the refrigerant pressure output from the first refrigerant hole Y16 fluctuates.

(modification 8)

In each of the above embodiments, the holes communicating with the through hole Y120 from the outside of the micro valve Y1 are three holes, i.e., the first refrigerant hole Y16, the second refrigerant hole Y17, and the third refrigerant hole Y18. However, the number of refrigerant holes communicating with through-hole Y120 from the outside of micro valve Y1 may be four or more.

The opening degree of the fourth and subsequent refrigerant holes may be adjusted by the movement of the movable portion Y128, or may not be adjusted. The fourth and subsequent refrigerant ports may communicate with the back pressure chamber 51m similarly to the first refrigerant port Y16. The fourth and subsequent refrigerant ports may communicate with the high-pressure refrigerant passage 51c, similarly to the second refrigerant port Y17. The fourth and subsequent refrigerant ports may communicate with the low-pressure refrigerant passage 51k, similarly to the third refrigerant port Y18. The fourth and subsequent refrigerant ports may be flow passages through which a refrigerant of a pressure different from both the high pressure and the low pressure flows, and may communicate with a flow passage other than the back pressure chamber 51 m.

(modification 9)

In the above embodiment, the expansion valve 5 is applied to a cooler cycle for air conditioning the vehicle interior in the refrigeration cycle. However, the application target of the expansion valve 5 may be a refrigeration cycle for other applications. For example, the present invention may be applied to a heat pump cycle for a vehicle as a flow rate adjustment valve, or may be applied to a battery cooler for a vehicle as a flow rate adjustment valve. In such an application example, if the expansion valve 5 fails, the influence on the travel distance and the battery is large. Therefore, it is advantageous to notify the failure of the expansion valve 5 or the failure of the microvalve Y1 to the vehicle-mounted device outside the expansion valve 5.

(modification 10)

In the above embodiments, an expansion valve is given as an example of a valve device that adjusts a flow rate by a valve. However, the valve device for adjusting the flow rate by moving the valve using microvalve Y1 is not limited to the expansion valve, and may be another flow rate adjustment valve in the refrigeration cycle.

(modification 11)

The shape and size of the microvalve Y1 are not limited to those shown in the above embodiments. The microvalve Y1 may have a first refrigerant port Y16, a second refrigerant port Y17, and a third refrigerant port Y18, which have a hydraulic pressure diameter capable of controlling an extremely small flow rate and preventing clogging of fine dust present in the flow path.

(modification 12)

In the above embodiment, the second communication hole YV2 communicates the second refrigerant hole Y17 with the high-pressure refrigerant passage 51 c. However, the communication destination between the second communication hole YV2 and the second refrigerant hole Y17 is not limited to the high-pressure refrigerant passage 51c, and may be any position as long as a flow path through which a refrigerant having a pressure higher than the pressure of the refrigerant flowing through the low-pressure refrigerant passage 51k flows.

(modification 13)

In the fourth, fifth, sixth, and ninth embodiments, the control pressure is output from the first refrigerant port Y16 to the outside of the micro valve Y1, the second refrigerant port Y17 communicates with the high-pressure passage outside the micro valve Y1, and the third refrigerant port Y18 is substantially closed. In other embodiments, the control pressure is output from the first refrigerant hole Y16 to the outside of the micro valve Y1, the second refrigerant hole Y17 communicates with the high-pressure passage outside the micro valve Y1, and the third refrigerant hole Y18 communicates with the low-pressure passage outside the micro valve Y1. In addition to these, there may be the following examples: the control pressure is output from the first refrigerant port Y16 to the outside of the micro valve Y1, the second refrigerant port Y17 is substantially closed, and the third refrigerant port Y18 communicates with the low-pressure passage outside the micro valve Y1.

(modification 14)

In the above embodiment, the high-pressure refrigerant passage 51c inside the expansion valve 5 is illustrated as an example of the first passage communicating with the second refrigerant hole Y17. However, the first passage communicating with the second refrigerant hole Y17 may be located outside the expansion valve 5 as long as a refrigerant having a pressure higher than the pressure of the low-pressure refrigerant flowing out of the expansion valve 5 flows through the first passage.

(modification 15)

The first communication hole YV1, the second communication hole YV2, and the third communication hole YV3 in the above embodiment are separate members from the main body 51, but may be integrally formed with the main body 51.

(modification 16)

In the above embodiment, the physical quantities detected by the composite sensor 54c are the pressure and temperature in the refrigerant passage 51f after evaporation. However, the physical quantity detected by the composite sensor 54c may be only the pressure in the refrigerant passage 51f after evaporation, or may be only the temperature in the refrigerant passage 51f after evaporation. The physical quantity detected by the composite sensor 54c may be another physical quantity that is neither the pressure nor the temperature.

(modification 17)

In the fourth to 10 embodiments, the second communication hole YV2 is formed in the second projection Y22 penetrating the interior of the post-evaporation refrigerant passage 51f, and thus extends from the microvalve Y1 side of the post-evaporation refrigerant passage 51f to the pressure chamber 58a side beyond the post-evaporation refrigerant passage 51 f. However, the second communication hole YV2 may extend from the microvalve Y1 side of the refrigerant passage 51f after evaporation to the pressure chamber 58a side beyond the refrigerant passage 51f after evaporation at a position shifted in the thickness direction of the expansion valve 5 with respect to the refrigerant passage 51f after evaporation.

(conclusion)

According to a first aspect shown in part or all of the embodiments described above, a valve device for a refrigeration cycle includes: a body having an inlet port, an outlet port, and a valve chamber for allowing a refrigerant flowing from the inlet port to the outlet port to flow therethrough; a valve body that is displaced in the valve chamber to adjust a flow rate of the refrigerant flowing from the inlet port to the outlet port through the valve chamber; and a control valve member that changes a pressure acting on a pressure chamber that generates a control pressure for moving the valve element, the control valve member having: a base portion formed with a refrigerant chamber through which a refrigerant flows, a first refrigerant hole communicating with the refrigerant chamber and communicating with the pressure chamber, and a second refrigerant hole communicating with the refrigerant chamber and communicating with a passage of the refrigerant outside the control valve member; a driving unit that displaces when its temperature changes; an amplification unit that amplifies a displacement of the drive unit caused by a change in temperature; and a movable portion that moves in the refrigerant chamber by being transmitted with a displacement amplified by the amplifying portion, thereby adjusting an opening degree of the second refrigerant hole with respect to the refrigerant chamber, wherein when the driving portion is displaced due to a change in temperature, the driving portion biases the amplifying portion at a biasing position, thereby displacing the amplifying portion about a hinge as a fulcrum, and the amplifying portion biases the movable portion at a connecting position of the amplifying portion and the movable portion, and a distance from the hinge to the connecting position is longer than a distance from the hinge to the biasing position.

Further, according to a second aspect, the pressure chamber is the valve chamber, the passage communicating with the second refrigerant hole is a first passage through which a high-pressure refrigerant flows, a third refrigerant hole communicating with a second passage through which a low-pressure refrigerant lower than the high pressure flows and communicating with the refrigerant chamber is formed in the base portion, and the movable portion is moved in the refrigerant chamber by transmitting displacement amplified by the amplifying portion, thereby adjusting at least one of an opening degree of the second refrigerant hole with respect to the refrigerant chamber and an opening degree of the third refrigerant hole with respect to the refrigerant chamber. Thus, the valve member does not pass through the flow path of the output control pressure and communicates with the low pressure.

In addition, according to a third aspect, the base portion includes a first outer layer having a plate shape, a second outer layer having a plate shape, and a fixing portion that is sandwiched and fixed between the first outer layer and the second outer layer, and the first refrigerant hole, the second refrigerant hole, and the third refrigerant hole are formed in the second outer layer. With this configuration, the flow passage in the control valve member has a U-turn structure.

In addition, according to a fourth aspect, the second outer layer is disposed on a side closer to the valve body than the first outer layer, and the first passage and the second passage are formed in the main body. By configuring in this manner, the flow path through which the refrigerant flows from the control valve member to the main body can be shortened as compared with the case where the first outer layer is disposed on the side closer to the valve body than the second outer layer. Further, the valve device can be miniaturized.

In addition, according to a fifth aspect, a hole through which an electric wire for changing the temperature of the driving unit passes is formed in the first outer layer. In this way, the flow path of the control valve member has a U-turn structure, and a hole through which the electric wiring passes is formed in the first outer layer on the side opposite to the first refrigerant hole side. Also, the second outer layer is closer to the valve element than the first outer layer. Therefore, the harness can be placed on the side closer to the atmosphere than the flow path of the refrigerant located on the first refrigerant hole side. Therefore, the necessity of a sealing structure such as an airtight portion for reducing the influence of the refrigerant atmosphere on the electric wiring is reduced.

Further, according to a sixth aspect, the movable portion is controlled to a first position that fully closes the second refrigerant hole with respect to the refrigerant chamber and fully opens the third refrigerant hole with respect to the refrigerant chamber, a second position that fully opens the second refrigerant hole with respect to the refrigerant chamber and fully closes the third refrigerant hole with respect to the refrigerant chamber, and an intermediate position that opens the second refrigerant hole with respect to the refrigerant chamber at an intermediate opening degree between the full opening and opens the third refrigerant hole with respect to the refrigerant chamber at an intermediate opening degree between the full opening and the full opening. With this configuration, the refrigerant pressure output from the first refrigerant hole can be adjusted in a wide range between the high pressure introduced from the second refrigerant hole and the low pressure introduced from the third refrigerant hole.

Further, according to a seventh aspect, the valve device is an expansion valve for decompressing and expanding the refrigerant on the upstream side of the refrigerant flow of the evaporator in the refrigeration cycle, and the valve device includes a self-service portion fixed to the main body, the self-service portion including: a composite sensor that detects a temperature and a pressure of refrigerant flowing out of the evaporator; and a drive circuit for controlling the temperature of the drive unit based on the temperature and pressure detected by the composite sensor. With this configuration, the valve device can autonomously adjust the flow rate.

In addition, according to an eighth aspect, the valve device includes a gap sensor that is fixed to the main body and detects a lift amount of the valve body. By providing such a gap sensor, information for identifying the presence or absence of a failure of the valve device can be acquired.

In addition, according to a ninth aspect, the control valve member includes a failure detection unit that outputs a signal for determining whether the control valve member is operating normally or has failed. By outputting such a signal from the control valve member, the presence or absence of a failure of the control valve member can be easily determined.

In addition, according to a tenth aspect, the signal is a signal corresponding to a strain amount of the amplifying section. With this configuration, the presence or absence of a failure of the valve device can be discriminated based on the relationship between the signal and the control amount for controlling the control valve member.

In addition, according to an eleventh aspect, the driving unit generates heat by energization, and the failure detecting unit outputs the signal to a device that stops energization to the pilot valve member when the pilot valve member fails. By stopping the energization at the time of failure of the control valve member in this way, the safety at the time of failure can be improved.

Further, according to a twelfth aspect, the valve device includes a circuit that can notify a control device that controls a notification device that notifies a person, and the circuit receives the signal from the failure detection unit, determines whether the control valve member is operating normally or has failed based on the signal, and notifies the control device to cause the notification device to notify that the control valve member has failed based on the determination that the failure has occurred. Thereby, one can know the failure of the control valve member.

In addition, according to a thirteenth aspect, the control valve member is constituted by a semiconductor chip. Therefore, the control valve member can be configured to be small.

In addition, according to a fourteenth aspect, the valve device is an expansion valve that decompresses refrigerant, the passage communicating with the second refrigerant hole is a first passage through which high-pressure refrigerant before being decompressed by the expansion valve flows, in the refrigeration cycle, the refrigerant condensed by a condenser for condensing the refrigerant flows into the inlet port, the refrigerant flowing from the inlet port passes through a throttle passage formed between the valve body and the valve seat, so as to be decompressed to a lower pressure than the high-pressure refrigerant, the refrigerant decompressed by the throttle passage passes through a second passage and thereafter flows out from the outflow port, the outflow port communicates with an inlet side of an evaporator that evaporates refrigerant in the refrigeration cycle, the valve device is provided with a low-pressure communication flow path that leads the refrigerant of the refrigerant chamber to the second passage.

In this way, the low-pressure communication flow passage guides the refrigerant in the refrigerant chamber to the second passage, whereby the refrigerant guided to the second passage flows into the evaporator. Therefore, the refrigerant that does not contribute to heat exchange can be reduced as compared with a case where the refrigerant guided from the refrigerant chamber to the low-pressure side does not flow into the evaporator. Further, the possibility of wasteful use of the refrigerant is reduced, and the efficiency of the refrigeration cycle is improved.

Further, according to a fifteenth aspect, the first refrigerant hole outputs a control pressure higher than a low pressure of the second passage to the pressure chamber, the low-pressure communication passage is formed to guide the refrigerant flowing out from the first refrigerant hole to the second passage, and a throttle portion whose passage cross-sectional area is reduced along the low-pressure communication passage is provided in the low-pressure communication passage.

In this way, the low-pressure communication flow passage is configured to guide the refrigerant flowing out of the first refrigerant hole to the second passage, and therefore, it is not necessary to provide a refrigerant hole different from both the first refrigerant hole and the second refrigerant hole in the control valve member and communicate the refrigerant hole with the low-pressure communication flow passage. In addition, in such a configuration, since the throttle portion is formed in the low-pressure communication flow passage, a pressure difference can be generated between the front and rear of the throttle portion, and therefore, the possibility of the function of the first refrigerant hole such as the output control pressure being impaired is reduced.

In addition, according to a sixteenth aspect, the valve device includes a movable pressure transmission portion that receives the control pressure generated in the pressure chamber and transmits a force corresponding to the control pressure to the valve body, wherein the pressure transmission portion extends from the pressure chamber to the valve body through the second passage, and the low-pressure communication passage is formed inside the pressure transmission portion and communicates from the pressure chamber to the second passage. In this way, with the pressure transmitting portion receiving the control pressure of the pressure chamber and passing through the second passage, the low-pressure communication passage communicating from the pressure chamber to the second passage is formed, so that it is not necessary to provide a member only for the low-pressure communication passage.

Further, according to a seventeenth aspect, the valve body includes a movable pressure transmission portion that receives the control pressure generated in the pressure chamber and transmits a force corresponding to the control pressure to the valve body, the main body has a housing hole that houses the pressure transmission portion, the housing hole includes the pressure chamber and communicates with the second passage, the pressure transmission portion extends to the valve body through the housing hole and the second passage, and the low-pressure communication passage is provided as a gap between an inner peripheral surface of the housing hole and the pressure transmission portion.

In this way, the low-pressure communication flow path can be provided in the gap between the inner peripheral surface of the housing hole and the outer peripheral surface of the pressure transmission portion by utilizing the case where the housing hole includes the pressure chamber and communicates with the second passage and the case where the pressure transmission portion receives the control pressure of the pressure chamber and passes through the second passage. By so doing, it is not necessary to provide a member only for the low-pressure communication flow path.

Further, according to an eighteenth aspect, the passage communicating with the second refrigerant hole is a first passage through which a high-pressure refrigerant flows, a third refrigerant hole communicating with the second passage through which a low-pressure flow lower than the high pressure flows and communicating with the refrigerant chamber is formed in the base portion, and the movable portion is moved in the refrigerant chamber by transmitting the displacement amplified by the amplifying portion, thereby adjusting at least one of the opening degree of the second refrigerant hole with respect to the refrigerant chamber and the opening degree of the third refrigerant hole with respect to the refrigerant chamber.

With this arrangement, the possibility of wasteful use of the refrigerant in the control valve member having the third refrigerant hole and capable of adjusting the control pressure by the opening degree adjustment is reduced, and the efficiency of the refrigeration cycle is improved.

Further, according to a nineteenth aspect, the inflow port is a first inflow port, the outflow port is a first outflow port, the refrigeration cycle includes a compressor that compresses the refrigerant evaporated by the evaporator, and the main body includes: a second inlet port into which the low-pressure refrigerant flowing out of the evaporator flows; a second outlet port through which the refrigerant flows out to a suction side of the compressor; and a post-evaporation refrigerant passage that reaches the second outlet from the second inlet, the valve device including: a movable pressure transmission portion that transmits a force corresponding to a pressure of the refrigerant in the pressure chamber to the valve body; an elastic body that elastically urges the valve element from a side opposite to the pressure transmission portion; and an adjusting portion that adjusts an elastic force of the elastic body, wherein the main body includes the evaporated refrigerant passage, the pressure chamber, the pressure transmission portion, the valve body, the elastic body, and the adjusting portion arranged in this order, the second passage is arranged on a side of the valve body with respect to the evaporated refrigerant passage, the adjusting portion includes an operation receiving portion that is exposed to an outside of the main body on a side opposite to the valve body, the operation receiving portion is capable of receiving an operation for adjusting the elastic force of the elastic body from the outside of the main body, and the low-pressure communication passage communicates with the second passage across the evaporated refrigerant passage from the third refrigerant hole.

In this way, the control valve member is positioned on the opposite side of the evaporated refrigerant passage from the adjusting portion, which is capable of receiving an operation for adjusting the elastic force of the elastic body from the outside of the main body and is positioned on the same side as the valve body with respect to the evaporated refrigerant passage, the valve body, and the second passage, so as to avoid interference with the adjusting portion. In this case, the low-pressure communication flow passage is caused to communicate with the second passage from the third refrigerant hole across the evaporated refrigerant passage, so that the refrigerant can be guided from the control valve member to the second passage while avoiding interference between the control valve member and the adjustment portion.

In addition, according to a twentieth aspect, the refrigerant control device further includes a low-pressure pipe that penetrates the evaporated refrigerant passage from the control valve member side to the second passage side, and the low-pressure communication passage is formed inside the low-pressure pipe. With this configuration, even if the refrigerant passage after evaporation intersects the low-pressure communication passage, both passages are insulated from each other. Further, the body shape of the valve device in the direction intersecting the arrangement direction of the evaporated refrigerant passage, the pressure chamber, the pressure transmission portion, and the valve body and intersecting the extending direction of the evaporated refrigerant passage can be suppressed.

Further, according to a twenty-first aspect, the low-pressure communication passage is formed outside the post-evaporation refrigerant passage in the main body, and thereby communicates with the second passage bypassing the post-evaporation refrigerant passage from the third refrigerant hole. With this configuration, the refrigerant flowing out of the third refrigerant hole can be guided to the second passage over the evaporated refrigerant passage by utilizing the inside of the main body in the direction intersecting the arrangement direction of the evaporated refrigerant passage, the pressure chamber, the pressure transmitting portion, and the valve body and intersecting the extending direction of the evaporated refrigerant passage.

Further, according to a twenty-second aspect, the refrigeration cycle includes a compressor that compresses a refrigerant evaporated by an evaporator that evaporates the refrigerant in the refrigeration cycle, the valve device is an expansion valve that reduces pressure of the refrigerant, the inflow port is a first inflow port, the outflow port is a first outflow port, the passage communicating with the second refrigerant hole is a first passage through which a high-pressure refrigerant before being reduced in pressure by the expansion valve flows, the refrigerant condensed by a condenser that condenses the refrigerant in the refrigeration cycle flows into the first inflow port, the refrigerant flowing in from the first inflow port passes through a throttle passage formed between the valve body and a valve seat and is reduced in pressure to a lower pressure than the high-pressure refrigerant, and the refrigerant reduced in pressure by the throttle passage passes through a second passage and thereafter flows out from the first outflow port, the first outflow port communicates with an inlet side of the evaporator, and the main body is formed with: a second inlet port into which the low-pressure refrigerant flowing out of the evaporator flows; a second outlet port through which the refrigerant flows out to a suction side of the compressor; and a post-evaporation refrigerant passage that reaches the second outlet from the second inlet, the valve device including: a sensor that outputs a signal corresponding to a physical quantity regarding the refrigerant passing through the post-evaporation refrigerant passage; and a drive circuit that controls an operation of the control valve member based on the signal output from the sensor, wherein the sensor, the control valve member, and the drive circuit are disposed on a side opposite to the valve body with reference to the post-evaporation refrigerant passage. With this configuration, the wiring of the electric wiring among the sensor, the control valve member, and the drive circuit is facilitated.

Further, according to a twenty-third aspect, in the main body, the control valve member, the refrigerant passage after evaporation, and the pressure chamber are arranged in this order, and the valve device includes: a control pressure pipe that passes through the evaporated refrigerant passage from the control valve member side to the pressure chamber side; and a movable pressure transmission portion that transmits a force corresponding to a pressure of the refrigerant in the pressure chamber to the valve body, wherein a control pressure introduction hole that communicates with the first refrigerant hole at a position closer to the control valve member than the evaporated refrigerant passage and communicates with the pressure chamber at a position closer to the pressure chamber than the evaporated refrigerant passage is formed in the control pressure pipe.

With this configuration, the control pressure can be applied from the control valve member through the control pressure introduction hole formed in the control pressure pipe penetrating the post-evaporation refrigerant passage. Therefore, while the function of the control valve member is also maintained, the handling of the electric wiring among the sensor, the control valve member, and the drive circuit becomes easy. Further, the body shape of the valve device in the direction intersecting the arrangement direction of the control valve member, the evaporated refrigerant passage, and the pressure chamber and intersecting the extending direction of the evaporated refrigerant passage can be suppressed.

In addition, according to a twenty-fourth aspect, the sensor and the control valve member are integrally assembled to the main body. By configuring in this manner, the labor for the assembly work and the components for assembly can be reduced as compared with the case where the sensor and the control valve member are assembled as separate bodies to the main body.

Claims

1. A valve device for a refrigeration cycle, comprising:

a body (51) having an inlet (51a), an outlet (51b), and a valve chamber (51g) through which a refrigerant flowing from the inlet to the outlet flows;

a valve body (52) that is displaced in the valve chamber to adjust the flow rate of the refrigerant flowing from the inlet port to the outlet port through the valve chamber; and

a control valve member (Y1) that changes a pressure acting on the pressure chambers (51g, 58a), the pressure chambers (51g, 58a) generating a control pressure for moving the valve element,

the control valve member has:

a base (Y11, Y121, Y13) formed with a refrigerant chamber (Y19) through which a refrigerant flows, a first refrigerant hole (Y16) communicating with the refrigerant chamber and with the pressure chamber, and a second refrigerant hole (Y17, Y18) communicating with the refrigerant chamber and with a passage (51c, 51k) of the refrigerant outside the control valve member;

a drive unit (Y123, Y124, Y125) that displaces when the temperature of the drive unit changes;

an amplification unit (Y126, Y127) that amplifies the displacement of the drive unit caused by a change in temperature; and

a movable part (Y128) that is moved in the refrigerant chamber by transmitting the displacement amplified by the amplification part, and adjusts the opening degree of the second refrigerant hole with respect to the refrigerant chamber,

when the driving portion is displaced due to a change in temperature, the driving portion biases the amplifying portion at a biasing position (YP2) so that the amplifying portion is displaced about a hinge (YP0) as a fulcrum and the amplifying portion biases the movable portion at a connecting position (YP3) between the amplifying portion and the movable portion,

2. The valve device according to claim 1,

the pressure chamber is the valve chamber and,

the passage communicating with the second refrigerant hole is a first passage (51c) through which a high-pressure refrigerant flows,

a third refrigerant hole (Y18) communicating with a second passage (51k) through which a low pressure lower than the high pressure flows and with the refrigerant chamber is formed in the base portion,

the movable portion is moved in the refrigerant chamber by transmitting the displacement amplified by the amplifying portion, and thereby at least one of the opening degree of the second refrigerant hole with respect to the refrigerant chamber and the opening degree of the third refrigerant hole with respect to the refrigerant chamber is adjusted.

3. The valve device according to claim 2,

the base part has a first outer layer (Y11) having a plate shape, a second outer layer (Y13) having a plate shape, and a fixing part (Y121) fixed by being sandwiched between the first outer layer and the second outer layer,

the first refrigerant hole, the second refrigerant hole, and the third refrigerant hole are formed in the second outer layer.

4. The valve device according to claim 3,

the second outer layer is disposed on a side closer to the valve element than the first outer layer,

the first and second passages are formed in the body.

5. The valve device according to claim 3,

holes (Y14, Y15) for passing electric wires (Y6, Y7) for changing the temperature of the drive unit are formed in the first outer layer.

6. The valve device according to any one of claims 2 to 5,

the movable portion is controlled to a first position that fully closes the second refrigerant hole with respect to the refrigerant chamber and fully opens the third refrigerant hole with respect to the refrigerant chamber, a second position that fully opens the second refrigerant hole with respect to the refrigerant chamber and fully closes the third refrigerant hole with respect to the refrigerant chamber, and an intermediate position that opens the second refrigerant hole with respect to the refrigerant chamber at an intermediate opening degree between the fully open and opens the third refrigerant hole with respect to the refrigerant chamber at an intermediate opening degree between the fully open and the fully open.

7. The valve device according to any one of claims 1 to 6,

a clearance sensor (55) is provided, which is fixed to the main body and detects the amount of lift of the valve element.

8. The valve device according to any one of claims 1 to 7,

the valve device is an expansion valve for decompressing and expanding the refrigerant on the upstream side of the evaporator (6) in the refrigerant flow in the refrigeration cycle,

the valve device comprises a main body (54) fixed on the main body,

the self-host section has: a composite sensor (54c) that detects the temperature and pressure of the refrigerant flowing out of the evaporator; and a drive circuit (54d) for controlling the temperature of the drive unit on the basis of the temperature and pressure detected by the composite sensor.

9. The valve device according to any one of claims 1 to 6,

the control valve member is provided with a failure detection unit (Y50) that outputs a signal for identifying whether the control valve member is operating normally or has failed.

10. The valve device according to claim 9,

the signal is a signal corresponding to the amount of strain of the amplifying section.

11. The valve device according to claim 9 or 10,

the drive portion generates heat by being energized,

the failure detection unit outputs the signal to a device (54d) that stops energization of the pilot valve member when the pilot valve member fails.

12. The valve device according to claim 9 or 10,

a circuit (54d) which can notify a control device (Y55) that controls a notification device (Y56) that notifies a person,

the circuit receives the signal from the failure detection unit, determines whether the control valve member is operating normally or has failed based on the signal, and notifies the control device to cause the notification device to notify that the control valve member has failed based on the determination that the failure has occurred.

13. The valve device according to any one of claims 1 to 12,

the control valve member is formed of a semiconductor chip.

14. The valve device according to claim 1,

the valve device is an expansion valve for decompressing the refrigerant,

the passage communicating with the second refrigerant hole is a first passage (51c) through which a high-pressure refrigerant before being decompressed by the expansion valve flows,

in the refrigeration cycle, the refrigerant condensed by a condenser (3) for condensing the refrigerant flows into the inflow port,

the refrigerant flowing in from the inlet port passes through a throttle passage (51h) formed between the valve body and a valve seat (51j), is reduced in pressure to a lower pressure than the high-pressure refrigerant, passes through the throttle passage (51h), is reduced in pressure, passes through a second passage (51k), and then flows out from the outlet port,

the outflow port communicates with an inlet side of an evaporator (6) that evaporates refrigerant in the refrigeration cycle,

the valve device is provided with a low-pressure communication flow path (58b, YV3) for guiding the refrigerant in the refrigerant chamber to the second path.

15. The valve apparatus of claim 14,

the first refrigerant hole outputs a control pressure higher than a low pressure of the second passage to the pressure chamber,

the low pressure communication flow path is formed to guide the refrigerant flowing out of the first refrigerant hole to the second passage,

the low-pressure communication flow path is provided with throttle portions (58c, 66a) having a flow path cross-sectional area that decreases along the low-pressure communication flow path.

16. The valve apparatus of claim 15,

a movable pressure transmission unit (65) that receives the control pressure generated in the pressure chamber and transmits a force corresponding to the control pressure to the valve body,

the pressure transmitting portion extends from the pressure chamber to the valve element through the second passage,

the low-pressure communication flow passage is formed inside the pressure transmission portion and communicates from the pressure chamber to the second passage.

17. The valve apparatus of claim 15,

a receiving hole (58) for receiving the pressure transmission part is formed on the main body,

the housing hole includes the pressure chamber and communicates with the second passage,

the pressure transmitting portion extends to the valve body through the accommodating hole and the second passage,

the low-pressure communication flow path is provided as a gap between an inner peripheral surface of the housing hole and the pressure transmission portion.

18. The valve apparatus of claim 14,

a third refrigerant hole (Y18) communicating with the second passage through which a low pressure flow lower than the high pressure flows and with the refrigerant chamber is formed in the base portion,

19. The valve apparatus of claim 18,

the flow inlet is a first flow inlet and,

the outflow opening is a first outflow opening,

the refrigeration cycle includes a compressor (2) that compresses the refrigerant evaporated by the evaporator,

the main body is provided with: a second inlet (51d) into which the low-pressure refrigerant flowing out of the evaporator flows; a second outlet (51e) through which the refrigerant flows out to the suction side of the compressor; and a post-evaporation refrigerant passage (51f) that is a passage from the second inlet port to the second outlet port,

the valve device is provided with: a movable pressure transmission unit (65) that transmits a force corresponding to the pressure of the refrigerant in the pressure chamber to the valve body; an elastic body (53) that biases the valve element with an elastic force from a side opposite to the pressure transmission portion; and an adjusting part (67) for adjusting the elastic force of the elastic body,

in the main body, the evaporated refrigerant passage, the pressure chamber, the pressure transmission portion, the valve body, the elastic body, and the adjustment portion are arranged in this order, the second passage is arranged on one side of the valve body with respect to the evaporated refrigerant passage,

an operation receiving portion (67a) is formed in the adjusting portion, the operation receiving portion being exposed to the outside of the main body on the side opposite to the valve body,

the operation receiving portion can receive an operation for adjusting the elastic force of the elastic body from the outside of the main body,

the low-pressure communication flow path passes through the evaporated refrigerant passage from the third refrigerant hole and communicates with the second passage.

20. The valve apparatus of claim 19,

a low-pressure pipe (Y23) that penetrates the evaporated refrigerant passage from the control valve member side to the second passage side,

the low-pressure communication flow path is formed inside the low-pressure pipe.

21. The valve apparatus of claim 19,

the low-pressure communication flow passage is formed in the main body outside the post-evaporation refrigerant passage, thereby bypassing the post-evaporation refrigerant passage from the third refrigerant hole and communicating with the second passage.

22. The valve apparatus according to any one of claims 1, 14 to 21,

the refrigeration cycle includes a compressor (2) that compresses a refrigerant evaporated by an evaporator (6) that evaporates the refrigerant in the refrigeration cycle,

the valve device is an expansion valve for decompressing the refrigerant,

the flow inlet is a first flow inlet and,

the outflow opening is a first outflow opening,

the refrigerant condensed by a condenser (3) for condensing the refrigerant in the refrigeration cycle flows into the first inflow port,

the refrigerant flowing in from the first inlet/outlet port passes through a throttle passage (51h) formed between the valve body and a valve seat (51j), is depressurized to a lower pressure than the high-pressure refrigerant, and the refrigerant depressurized through the throttle passage (51h) passes through a second passage (51k) and then flows out from the first outlet/outlet port,

the first outflow port communicates with an inlet side of the evaporator,

the valve device is provided with: a sensor (54) that outputs a signal corresponding to a physical quantity relating to the refrigerant passing through the post-evaporation refrigerant passage; and a drive circuit (54d) that controls the operation of the control valve member based on the signal output from the sensor,

the sensor, the control valve member, and the drive circuit are disposed on a side opposite to the valve body with reference to the evaporated refrigerant passage.

23. The valve apparatus of claim 22,

in the main body, the control valve member, the evaporated refrigerant passage, and the pressure chamber are arranged in this order,

the valve device is provided with: a control pressure pipe (Y21) that passes the evaporated refrigerant passage from the control valve member side to the pressure chamber side; and a movable pressure transmission unit (65) that transmits a force corresponding to the pressure of the refrigerant in the pressure chamber to the valve body,

a control pressure introduction hole (YV1) that communicates with the first refrigerant hole at a position closer to the control valve member than the post-evaporation refrigerant passage and communicates with the pressure chamber at a position closer to the pressure chamber side than the post-evaporation refrigerant passage is formed in the control pressure pipe.

24. The valve device according to claim 22 or 23,

the sensor and the control valve member are assembled to the main body as a single body.