Valve unit

Abstract

To make a valve unit integrated with a receiver compact in a size.SOLUTION: A valve unit 1 comprises a block 10 detachably assembled to an upper part of a receiver 108, and a plurality of control valves detachably assembled to the block 10. The receiver 108 includes a tank 20 which can store a refrigerant, an upper end member 52 for closing an upper end opening part of the tank 20, and a lower end member 54 for closing a lower end opening part of the tank 20. A first inlet port 140 and a first outlet port 142 constituting a second refrigerant circulation passage are formed at the upper end member 52, and the block is detachably attached thereto. A second inlet port 144 and a second outlet port 146 constituting a first refrigerant circulation passage are formed at the lower end member 54.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a valve unit provided integrally with a receiver for separating a refrigerant into a gas phase and a liquid phase.

Background Art

[0002] With the recent spread of electric vehicles, the development of their air conditioning systems has also been promoted. Since electric vehicles do not have a heat source by an internal combustion engine, a heat pump type air conditioning device that performs a cycle operation using a refrigerant not only for cooling but also for heating is adopted (see Patent Document 1).

[0003] Such a vehicle air conditioning device has a refrigeration cycle including a compressor, an outdoor heat exchanger, an expansion device, an evaporator, an indoor heat exchanger, etc., and the function of the outdoor heat exchanger is switched between heating operation and cooling operation. During heating operation, the outdoor heat exchanger functions as an evaporator. At that time, in the process where the refrigerant circulates in the refrigeration cycle, the indoor heat exchanger releases heat, and the air in the vehicle interior is heated by that heat. During cooling operation, the outdoor heat exchanger functions as a condenser. At that time, the refrigerant condensed in the outdoor heat exchanger is decompressed and expanded by the expansion device to become a gas-liquid two-phase refrigerant, and is evaporated in the evaporator. The air in the vehicle interior is cooled by the latent heat of evaporation.

[0004] In such a refrigeration cycle, in order to maintain stable heat exchange in the evaporator, a receiver dryer (hereinafter also simply referred to as "receiver") for separating and storing the refrigerant led out from the outdoor heat exchanger may be provided. Even if the condensation by the outdoor heat exchanger is insufficient, by leading the refrigerant in the liquid phase part of the receiver to the expansion device, a gas-liquid two-phase refrigerant necessary for heat exchange in the evaporator can be supplied. Also, for the surplus liquid refrigerant, by storing it in the receiver, an appropriate amount of liquid refrigerant can be supplied to the expansion device.

[0005] When a heat pump type heating and cooling system is adopted, the number of devices such as various control valves arranged in the refrigerant circulation passage increases. Therefore, it is important to save space in the vehicle by making multiple devices compact, such as by unitizing them into a single unit. In this regard, Patent Document 1 discloses a valve unit in which multiple control valves and a receiver are integrated via a block in which a refrigerant passage is formed. In this valve unit, the receiver has a bottomed cylindrical tank, and the block is provided to close the upper end opening of the tank. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-11578 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, receivers are generally equipped with a filter component to capture foreign matter contained in the refrigerant circulating in the refrigeration cycle. By suppressing the circulation of foreign matter in this way, the normal operation of the refrigeration cycle can be ensured. The filter component may also contain a desiccant to remove moisture from the refrigerant. Since such filter components are disposable parts, they need to be replaced periodically, and at that time, it is recommended to replace the entire receiver, which also serves as a system refresh.

[0008] In this regard, in the case of the valve unit described in Patent Document 1, since the block constitutes part of the receiver, it may be necessary to replace the entire receiver block. Also, since the refrigerant passages are concentrated at the top of the receiver, the block needs to be made larger as the refrigerant circulation passages become more complex. As the block becomes larger, its weight also increases, which increases the workload required to reassemble the valve unit.

[0009] One of the objectives of the present invention is to easily achieve a more compact valve unit in which a receiver is integrally provided. [Means for solving the problem]

[0010] One aspect of the present invention is a valve unit applied to a refrigeration cycle comprising a first refrigerant circulation passage that is opened during cooling operation and a second refrigerant circulation passage that is opened during heating operation. This valve unit comprises a receiver that separates the refrigerant flowing through the first refrigerant circulation passage into gas and liquid phases during cooling operation and the refrigerant flowing through the second refrigerant circulation passage into gas and liquid phases during heating operation; a block that is detachably mounted on the upper part of the receiver; and a plurality of control valves that are detachably mounted on the block and open and close the flow paths formed in the block.

[0011] The receiver includes a tank capable of storing refrigerant, an upper end member provided to close the upper end opening of the tank, and a lower end member provided to close the lower end opening of the tank. The upper end member is provided with a first inlet port and a first outlet port that constitute a second refrigerant circulation passage, and a block is detachably attached to it. The lower end member is provided with a second inlet port and a second outlet port that constitute a first refrigerant circulation passage.

[0012] In this embodiment, the receiver is constructed by closing the upper end opening of the tank with an upper end member and the lower end opening with a lower end member. Furthermore, since the block is detachably attached to the upper end member, the receiver and the block can be easily separated. In addition, since the lower end member is provided with a second inlet port and a second outlet port, a portion of the first refrigerant circulation passage can be formed in the lower part of the receiver. In other words, since it is not necessary to consolidate the passages for forming each refrigerant circulation passage into the block, the size of the block can be suppressed as the number of ports increases. As a result, it becomes easier to achieve a more compact valve unit. [Effects of the Invention]

[0013] According to the present invention, it is possible to easily achieve a more compact valve unit in which the receiver is integrally provided. [Brief explanation of the drawing]

[0014] [Figure 1] This is a system configuration diagram of a vehicle air conditioning and heating system according to an embodiment. [Figure 2] This is a diagram illustrating the operation of a heating and cooling system. [Figure 3] This is a diagram illustrating the operation of a heating and cooling system. [Figure 4] This is a diagram showing the external appearance of the valve unit. [Figure 5] This is a diagram showing the external appearance of the valve unit. [Figure 6] This is a diagram showing the external appearance of the valve unit. [Figure 7] This is a cross-sectional view showing the assembly structure of the receiver and block. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described in detail below with reference to the drawings. For convenience, the positional relationships of each structure may be expressed based on the illustrated state in the following description. In addition, substantially identical components in the following embodiments and their modifications will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0016] Figure 1 is a system configuration diagram of a vehicle air conditioning and heating system according to an embodiment. The air conditioning system 100 includes a refrigeration cycle (refrigerant circulation circuit) in which a compressor 102, an auxiliary condenser 104, an outdoor heat exchanger 106, a receiver 108, and an evaporator 110 are connected by piping. The air conditioning system 100 is configured as a heat pump type air conditioning system that uses the heat of a refrigerant, such as HFC-134a (alternative fluorocarbon) or HFO-1234yf, to provide air conditioning in the vehicle interior as the refrigerant circulates through the refrigeration cycle while undergoing a change of state.

[0017] The compressor 102, the outdoor heat exchanger 106, and the receiver 108 are provided outside the vehicle (engine room). On the other hand, a duct 112 for heat exchange of air is provided inside the vehicle. An evaporator 110 is disposed upstream in the air flow direction in the duct 112, and an auxiliary condenser 104 is disposed downstream. An air mix door 113 is rotatably provided upstream of the auxiliary condenser 104.

[0018] The air conditioner 100 is operated to switch between a plurality of refrigerant circulation paths during cooling operation and heating operation. This refrigeration cycle is configured such that the auxiliary condenser 104 and the outdoor heat exchanger 106 can operate in series as condensers, and the evaporator 110 and the outdoor heat exchanger 106 can be switched as evaporators. A first refrigerant circulation path through which refrigerant circulates during cooling operation and a second refrigerant circulation path through which refrigerant circulates during heating operation are formed.

[0019] The first refrigerant circulation path is a path through which refrigerant circulates as compressor 102 → auxiliary condenser 104 → outdoor heat exchanger 106 → receiver 108 → evaporator 110 → compressor 102 (see Fig. 2(A)). The second refrigerant circulation path is a path through which refrigerant circulates as compressor 102 → auxiliary condenser 104 → receiver 108 → outdoor heat exchanger 106 → compressor 102 (see Fig. 2(B)). That is, the second refrigerant circulation path is a path that bypasses the evaporator 110.

[0020] And a valve unit 1 for switching these refrigerant circulation paths is provided. The valve unit 1 is configured by assembling a solenoid valve 2, a solenoid valve 4, and an electric valve 6 to the receiver 108 via a block 10. A first inlet port 140 and a first outlet port 142 are provided at the upper part of the receiver 108, and a second inlet port 144 and a second outlet port 146 are provided at the lower part.

[0021] A gas phase space GS for storing gaseous refrigerant is formed in the upper part of the receiver 108, and a liquid phase space LS for storing liquid refrigerant is formed in the lower part. The first inlet port 140 communicates with the upper part of the receiver 108. The second inlet port 144 and the second outlet port 146 each communicate with the lower part of the receiver 108. The first outlet port 142 communicates with the lower part of the receiver 108 via the discharge pipe 148. A check valve 150 is provided in the lower part of the receiver 108 to prevent backflow of refrigerant through the second inlet port 144.

[0022] Block 10 has a first flow path 131, a second flow path 132, and a third flow path 133, and is detachably assembled to the top of the receiver 108. The first flow path 131 constitutes the first refrigerant circulation passage. The second flow path 132 constitutes the second refrigerant circulation passage and communicates with the first inlet port 140 of the receiver 108. The third flow path 133 constitutes the second refrigerant circulation passage and communicates with the first outlet port 142 of the receiver 108. The first flow path 131 and the third flow path 133 have a confluence point P in the middle. Block 10 is provided with a check valve 152 to prevent backflow of refrigerant in the third flow path 133.

[0023] Solenoid valves 2, 4, and 6 are each detachably assembled to block 10. Solenoid valve 2 is connected to the inlet of the first passage 131 and functions as a "first control valve" that opens and closes the first passage 131. Solenoid valve 4 is connected to the inlet of the second passage 132 and functions as a "second control valve" that opens and closes the second passage 132. 6 is connected to the outlets of the first passage 131 and the third passage 133 and functions as a "third control valve" that opens and closes the first passage 131 and the third passage 133. Details of the structure of valve unit 1 will be described later.

[0024] The outlet (discharge chamber) of the compressor 102 is connected to the inlet of the auxiliary condenser 104 via the first passage 121. The outlet of the auxiliary condenser 104 is connected to the inlet of the solenoid valve 2 via the second passage 122. The outlet of the solenoid valve 2 is connected to the inlet of the electric valve 6 via the first flow path 131. The outlet of the electric valve 6 is connected to the inlet of the outdoor heat exchanger 106 via the third passage 123. The outlet of the outdoor heat exchanger 106 is connected to the inlet of the compressor 102 via the fourth passage 124. A branching point P1 is provided in the middle of the fourth passage 124, from which the fifth passage 125 branches off.

[0025] The fifth passage 125 is connected to the second inlet port 144 of the receiver 108. The second outlet port 146 is connected to the inlet of the evaporator 110 via the sixth passage 126. An electric valve 114 is provided on the upstream side of the evaporator 110 in the sixth passage 126. The outlet of the evaporator 110 is connected to the inlet (suction chamber) of the compressor 102 via the seventh passage 127 (return passage) and the fourth passage 124. That is, a junction point P2 with the seventh passage 127 is provided on the upstream side of the compressor 102 in the fourth passage 124. An on-off valve 116 for opening and closing the fourth passage 124 is provided between the branching point P1 and the junction point P2 in the fourth passage 124. In this embodiment, the on-off valve 116 is a solenoid-driven electromagnetic valve, but it may also be a motor-driven electric valve.

[0026] A branching point P3 is provided midway through the second passage 122, from which the eighth passage 128 branches off. The eighth passage 128 is connected to the inlet of the solenoid valve 4. The outlet of the solenoid valve 4 is connected to the inlet of the second passage 132.

[0027] With this configuration, the first refrigerant circulation passage is formed by the first passage 121, the second passage 122, the first flow path 131, the third passage 123, the upstream part of the fourth passage 124 (upstream of branching point P1), and the fifth passage 125, the sixth passage 126, the seventh passage 127, and the downstream part of the fourth passage 124 (downstream of confluence point P2) (see Figure 2(A)).

[0028] Furthermore, a second refrigerant circulation passage is formed by the first passage 121, the second passage 122 (upstream of branching point P3), the eighth passage 128, the second flow path 132, the third flow path 133, the third passage 123, and the fourth passage 124 (see Figure 2(B)). In addition, a third refrigerant circulation passage is formed by the first passage 121, the second passage 122 (upstream of branching point P3), the eighth passage 128, the second flow path 132, the sixth passage 126, the seventh passage 127, and the downstream portion of the fourth passage 124 (downstream of confluence point P2) (see Figure 3(A)). Details of these will be described later.

[0029] The compressor 102 is configured as an electric compressor, housing a motor and a compression mechanism within a housing. The compressor 102 is driven by current supplied from a battery (not shown), and the refrigerant discharge capacity changes according to the motor's rotational speed. Since electric compressors themselves are well known, their explanation is omitted.

[0030] The auxiliary condenser 104 functions as an indoor condenser that dissipates heat from the refrigerant separately from the outdoor heat exchanger 106. In other words, the high-temperature, high-pressure refrigerant discharged from the compressor 102 dissipates heat as it passes through the auxiliary condenser 104.

[0031] The outdoor heat exchanger 106 functions as an outdoor condenser that releases heat from the refrigerant passing through it during cooling operation, while functioning as an outdoor evaporator that evaporates the refrigerant passing through it during heating operation. The outdoor heat exchanger 106 facilitates heat exchange between the outside air and the refrigerant. During cooling operation, the on-off valve 116 is closed, so the refrigerant that has passed through the outdoor heat exchanger 106 is led to the receiver 108. During heating operation, the on-off valve 116 is opened, so the refrigerant that has passed through the outdoor heat exchanger 106 is led to the compressor 102.

[0032] The electric valve 114 functions as an expansion valve during cooling operation, throttling and expanding the liquid refrigerant discharged from the receiver 108 and supplying it to the evaporator 110.

[0033] The evaporator 110 functions as an indoor evaporator that evaporates the refrigerant passing through it. The refrigerant, which has become low temperature and low pressure after passing through the electric valve 114, evaporates as it passes through the evaporator 110. The air introduced from the upstream side of the duct 112 is cooled by its latent heat of vaporization. At this time, the cooled and dehumidified air is divided into two parts: one that passes through the auxiliary condenser 104 and the other that bypasses the auxiliary condenser 104, depending on the opening degree of the air mix door 113. The air that passes through the auxiliary condenser 104 is heated during its passage. The air that has passed through the auxiliary condenser 104 and the bypassed air are mixed downstream of the auxiliary condenser 104 and adjusted to the target temperature, and supplied into the vehicle from an outlet (not shown).

[0034] The air conditioning system 100, configured as described above, is controlled by the control unit 130. The control unit 130 calculates the control amount for each actuator to achieve the room temperature set by the vehicle occupants and outputs a control signal to the drive circuit of each actuator. Based on predetermined external information detected by various sensors, such as the temperature inside and outside the vehicle and the temperature of the air blown out from the evaporator 110, the control unit 130 determines the control amount (open / closed state) of each control valve and the drive amount of the compressor 102, and supplies a control current to drive them. The compressor 102 introduces refrigerant at an intake pressure Ps through its intake chamber, compresses it, and discharges it as refrigerant at a discharge pressure Pd.

[0035] Figures 2 and 3 illustrate the operation of the heating and cooling system 100. Figure 2(A) shows the cooling operation, and Figure 2(B) shows the heating operation. Figures 3(A) and (B) show the dehumidifying heating operation. Thick lines and arrows in the figures indicate the flow of refrigerant, and "×" indicates that the flow of refrigerant is blocked.

[0036] (Air conditioning operation) As shown in Figure 2(A), during cooling operation, the solenoid valve 2 and the motor valve 6 in the valve unit 1 are in the open state, and the solenoid valve 4 is in the closed state. The motor valve 6 is controlled to be fully open. The motor valve 6 is a composite valve (also called a "large and small diameter valve") that drives a large-diameter first valve (large-diameter valve) and a small-diameter second valve (small-diameter valve) with a common actuator (motor), as described in, for example, Japanese Patent Application Publication No. 2022-146574. During cooling operation, the large-diameter valve is in the fully open state. Also, the on-off valve 116 is in the closed state, and the motor valve 114 is in a slightly open state where it functions as an expansion valve. At this time, the first flow path 131 is opened, the check valve 152 closes due to differential pressure, and the check valve 150 opens. As a result, the first refrigerant circulation passage is opened, and the second and third refrigerant circulation passages are blocked. Therefore, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 102 is condensed by passing through the auxiliary condenser 104 and the outdoor heat exchanger 106. The outdoor heat exchanger 106 functions as an outdoor condenser.

[0037] The refrigerant discharged from the outdoor heat exchanger 106 is separated into gas and liquid phases in the receiver 108, and the liquid refrigerant is supplied downstream. This liquid refrigerant is throttled and expanded by the electric valve 114, becoming a low-temperature, low-pressure mist of refrigerant, which is then introduced into the evaporator 110. As the refrigerant passes through the evaporator 110, it evaporates, cooling the air inside the vehicle. The refrigerant discharged from the evaporator 110 is returned to the compressor 102.

[0038] (Heating operation) As shown in Figure 2(B), during heating operation, the solenoid valve 4 and the motor valve 6 in the valve unit 1 are in the open state, and the solenoid valve 2 is in the closed state. Also, the on / off valve 116 is in the open state, and the motor valve 114 is in the closed state. At this time, the second flow path 132 is opened, and refrigerant is introduced into the receiver 108. Due to the differential pressure, the check valve 152 opens and the check valve 150 closes. As a result, the third flow path 133 is opened. The refrigerant in the lower part of the receiver 108 is discharged through the discharge pipe 148.

[0039] As a result, the second refrigerant circulation passage is opened, and the first and third refrigerant circulation passages are blocked. Therefore, the refrigerant does not pass through the evaporator 110, and the evaporator 110 effectively ceases to function. The electric valve 6 is controlled to a small opening and functions as an expansion valve. At this time, the large-diameter valve in the electric valve 6 closes, and the small-diameter valve controls the opening to a small degree. Only the outdoor heat exchanger 106 functions as an evaporator (outdoor evaporator).

[0040] In other words, the refrigerant discharged from the compressor 102 is condensed by passing through the auxiliary condenser 104. This refrigerant is separated into gas and liquid form in the receiver 108, and the liquid refrigerant is supplied downstream. This liquid refrigerant is throttled and expanded by the electric valve 6, becoming a low-temperature, low-pressure mist of refrigerant, which is then introduced into the outdoor heat exchanger 106. As the refrigerant passes through the outdoor heat exchanger 106, it evaporates and absorbs heat from the outside. The refrigerant discharged from the outdoor heat exchanger 106 becomes a gaseous refrigerant and is returned to the compressor 102. At this time, the air mix door 113 is opened wide, and the interior of the vehicle is warmed by the heat exchange in the auxiliary condenser 104.

[0041] (Dehumidifying and heating operation) As shown in Figure 3(A), in dehumidifying heating operation, the solenoid valve 4 in the valve unit 1 is in the open state, and the solenoid valve 2 and the motor valve 6 are in the closed state. Also, the on / off valve 116 is in the closed state, and the motor valve 114 is open and functions as an expansion valve. At this time, the second flow path 132 is opened, and the refrigerant is introduced into the receiver 108. The check valves 150 and 152 remain in the closed state, and the first flow path 131 and the third flow path 133 are blocked. As a result, the third refrigerant circulation passage is opened, and the first and second refrigerant circulation passages are blocked. Therefore, although the refrigerant discharged from the compressor 102 is guided to the valve unit 1 via the auxiliary condenser 104, it does not pass through the outdoor heat exchanger 106, but returns to the compressor 102 via the receiver 108, the motor valve 114, and the evaporator 110. At this time, the dehumidifying function of the evaporator 110 is performed. Because the air mix door 113 opens wide, the heating inside the vehicle is maintained.

[0042] In the modified configuration, as shown in Figure 3(B), the first refrigerant circulation passage may be opened during dehumidifying heating operation, and the electric valve 6 may be controlled to a small opening to function as an expansion valve. In this case, the electric valve 114 also functions as an expansion valve. The opening and closing control of the control valves other than the electric valve 6 is the same as during cooling operation as shown in Figure 2(A). The refrigerant evaporates as it passes through the outdoor heat exchanger 106, absorbing heat from the outside. The refrigerant discharged from the outdoor heat exchanger 106 returns to the compressor 102 via the receiver 108, electric valve 114, and evaporator 110. At this time, the dehumidifying function of the evaporator 110 is performed. Because the air mix door 113 is opened wide, heating inside the vehicle is maintained.

[0043] Next, we will describe the structure of valve unit 1. Figures 4 to 6 show the external appearance of the valve unit 1. Figure 4 is a perspective view from the upper left, Figure 5 is a front view, and Figure 6 is a top view. As shown in Figure 4, the valve unit 1 is constructed by assembling a block 10 to the upper end of a receiver 108, and assembling solenoid valves 2, 4, and motor valve 6 to the block 10. The receiver 108 includes a cylindrical tank 20.

[0044] As shown in Figures 5 and 6, the block 10 has a rectangular shape in both front and plan views, and is fixed to the upper end surface of the receiver 108 by a plurality of bolts 22. The solenoid valve 2, solenoid valve 4, and motor valve 6 are arranged side by side on the upper surface of the block 10 and are fixed to the block 10 by bolts (not shown) inserted through through holes 24. In a plan view of the block 10, the solenoid valve 2 is located in the center, with the solenoid valve 4 and motor valve 6 on either side of it.

[0045] The solenoid valve 2 is constructed by assembling a drive unit 32 (solenoid) to a block-shaped body 30. The drive unit 32 is exposed from the side of the body 30. The body 30 has an internal passage, and a valve section is provided in the middle of the internal passage. One end of the internal passage opens as an inlet port 34 on the upper surface of the body 30, and the other end of the internal passage opens as an outlet port on the lower surface of the body 30. The valve section can be opened and closed by driving the drive unit 32.

[0046] In this embodiment, the solenoid valve 4 has the same structure (same external shape) as the solenoid valve 2. However, in modified examples, while they share the common feature of having a solenoid as the drive unit, their specific structure and size, such as appearance and internal structure, may differ from that of the solenoid valve 2. Since the internal structure of such a solenoid valve is publicly known, a detailed explanation will be omitted.

[0047] The electric valve 6 is constructed by assembling a drive unit 42 (motor unit) to a block-shaped body 40. The drive unit 42 is exposed from the side of the body 40. The body 40 has an internal passage, and a valve section is provided in the middle of the internal passage. One end of the internal passage opens as an outlet port 46 on the upper surface of the body 40, and the other end of the internal passage opens as an inlet port on the lower surface of the body 40. The valve section can be opened and closed by driving the drive unit 42. The internal structure of such an electric valve is publicly known, as described in, for example, Japanese Patent Application Publication No. 2022-146574, so a detailed explanation is omitted.

[0048] Figure 7 is a cross-sectional view showing the assembly structure of the receiver 108 and block 10. This figure is an exploded view corresponding to the cross-sectional view taken along arrow AA in Figure 6. The receiver 108 comprises a cylindrical tank 20, an upper end member 52 provided to close the upper end opening of the tank 20, and a lower end member 54 provided to close the lower end opening of the tank 20. A filter member 56 is disposed in the vertical center of the tank 20.

[0049] The upper end member 52 is a disc-shaped member that is inserted into the upper end of the tank 20 and is airtightly fixed by welding to its outer circumference. A first inlet port 140 and a first outlet port 142 are provided so as to penetrate the upper end member 52 vertically.

[0050] The lower end member 54 is a disc-shaped member that is inserted into the lower end of the tank 20 and airtightly fixed by welding to its outer circumference. A second inlet port 144 and a second outlet port 146 are provided so as to penetrate the lower end member 54 vertically. A check valve 150 is disposed inside the second inlet port 144.

[0051] The lower end member 54 has a support portion 55 that protrudes in an embossed manner from the upper end opening of the second inlet port 144. The check valve 150 comprises a cylindrical body 154, a bearing member 156 assembled inside the body 154, and a valve body 158 supported by the bearing member 156. The body 154 is assembled so as to be inserted inside the support portion 55. A seal ring 160 is provided on the outer circumferential surface of the downstream end of the body 154 to ensure airtightness between it and the inner circumferential surface of the second inlet port 144. A valve seat 162 is provided on the upstream end of the body 154.

[0052] A sealing member 159 made of an elastic material such as rubber is fitted to the upstream end of the valve body 158. The valve body 158 is supported by a bearing member 156 so as to be slidable in the axial direction. A spring 164 is interposed between the valve body 158 and the bearing member 156 to bias the valve body 158 in the closing direction. The valve body 158 opens and closes the check valve 150 by attaching to and detaching from the valve seat 162 from the downstream side.

[0053] The filter member 56 is constructed by filling a desiccant 62 between a pair of upper and lower disc-shaped filters 60 and sandwiching them between a pair of support members 64. The filters 60 have the function of capturing foreign matter (dust, etc.) in the refrigerant, and the desiccant 62 has the function of removing moisture from the refrigerant. The support members 64 are disc-shaped metal plates and have numerous small holes for allowing gaseous refrigerant to pass through. These support members 64 are pressed into the tank 20, thereby fixing the filter member 56 to the center of the tank 20.

[0054] An insertion hole 66 is provided so as to penetrate the filter member 56 along its central axis, and the discharge pipe 148 passes through this insertion hole 66. The upper end of the discharge pipe 148 opens to the first outlet port 142, and the lower end opens to the lower part (near the bottom) of the tank 20. In this embodiment, since the upper end member 52 and the lower end member 54 are assembled to the tank 20, the discharge pipe 148 can be housed inside the tank 20 as shown in the figure.

[0055] As described above, the block 10 has a first channel 131, a second channel 132, and a third channel 133. The first channel 131 is a U-shaped channel whose inlet and outlet open to the upper surface of the block 10. The second channel 132 penetrates the block 10 in the vertical direction. The third channel 133 has one end opening to the lower surface of the block 10 and the other end opening to the upper surface of the block 10. The third channel 133 is connected to the first channel 131 at a confluence point P and shares an outlet with the first channel 131. The third channel 133 also functions as a mounting hole 135 for attaching a check valve 152. The open end of the mounting hole 135 is closed by a plug 137.

[0056] The check valve 152 has substantially the same configuration as the check valve 150. Therefore, the same reference numerals are used for similar components, and their descriptions are omitted. The check valve 152 has a seal ring 160 on the outer circumferential surface of the upstream end of the body 174, ensuring airtightness between it and the inner circumferential surface of the third flow path 133. A valve seat 162 is provided at the upstream end of the body 174. The valve body 158 attaches to and detaches from the valve seat 162 from the downstream side to open and close the check valve 152.

[0057] On the upper surface of block 10, there are protruding joint portions 70 which constitute the inlet of the first flow path 131, joint portions 72 which constitute the outlets of the first flow path 131 and the third flow path 133, and joint portion 74 which constitute the inlet of the second flow path 132. On the lower surface of block 10, there are protruding joint portions 76 which constitute the outlet of the second flow path 132 and joint portion 78 which constitute the inlet of the third flow path 133. A seal ring 80 (O-ring) is fitted to each joint portion.

[0058] When assembling the valve unit 1, the block 10 is attached to the receiver 108 by inserting the joint 76 into the first inlet port 140 and the joint 78 into the first outlet port 142. The two are then secured together with the aforementioned bolts 22. Furthermore, each control valve is attached to the block 10 by inserting the joint 70 into the outlet port of the solenoid valve 2, the joint 72 into the inlet port of the electric valve 6, and the joint 74 into the outlet port of the solenoid valve 4. The control valves are then secured to the block 10 with the aforementioned bolts.

[0059] As described above, in this embodiment, the receiver 108 is constructed by closing the upper end opening of the tank 20 with the upper end member 52 and closing the lower end opening with the lower end member 54. Furthermore, since the block 10 is detachably attached to the upper end member 52, the receiver 108 and the block 10 can be easily separated.

[0060] Furthermore, since the lower end member 54 is configured to have a second inlet port 144 and a second outlet port 146, a portion of the first refrigerant circulation passage can be formed in the lower part of the receiver 108. In other words, since it is not necessary to consolidate the passages for forming each refrigerant circulation passage into the block 10, it is possible to suppress the increase in the size of the block 10 in accordance with the increase in the number of ports. As a result, it becomes easier to make the valve unit 1 more compact.

[0061] By providing the second outlet port 146 on the lower end member 54, it can be kept away from the block 10, so that the liquid refrigerant discharged from the second outlet port 146 is not heated by the high-temperature refrigerant in the first flow path 131. This prevents the refrigerant cooled and condensed in the outdoor heat exchanger from being reheated before being sent to the evaporator, thus preventing it from affecting the system control.

[0062] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these specific embodiments, and various modifications are possible within the scope of the technical concept of the present invention.

[0063] [Differentiation] In the above embodiment, a combination of two solenoid valves and an electric valve was exemplified as the control valve assembled to block 10. In a modified example, at least one of solenoid valves 2 and 4 may be replaced with an electric valve. Alternatively, electric valve 6 may be replaced with a solenoid valve capable of functioning as an expansion valve. In the above embodiment, the on-off valve 116 was configured as a solenoid valve, but it may also be an electric valve.

[0064] In the above embodiment, as shown in Figure 1, a motor-driven electric valve 114 is exemplified, but a solenoid-driven electromagnetic valve may also be used. In that case, the electromagnetic valve controls the minute opening degree. Alternatively, a temperature-controlled expansion valve that operates by sensing the temperature and pressure of the refrigerant may be used. In that case, it is preferable to provide an on-off valve (such as a small electromagnetic valve) that is controlled to open and close by the control unit upstream of the temperature-controlled expansion valve.

[0065] In the above embodiment, as shown in Figure 7, a configuration in which the check valve 150 is provided inside the receiver 108 is illustrated. In a modified example, the check valve 150 may be provided in the external piping of the receiver 108 (specifically, in the piping that forms the fifth passage 125 (see Figure 1)). This allows the receiver 108 and, consequently the valve unit 1, to be made more compact.

[0066] In the above embodiment, as shown in Figure 7, the desiccant 62 is provided integrally with the filter 60 to form a filter member 56, which is then fixed inside the tank 20. In a modified example, the desiccant may be separated from the filter and placed inside the tank in a bag.

[0067] In the above embodiment, a large-diameter and small-diameter valve having multiple valves (large-diameter valve and small-diameter valve) was exemplified as the electric valve 6, but a rotary ball valve with an expansion function (for example, the configuration disclosed in International Publication No. 2022 / 117641) may also be used.

[0068] In the above embodiment, a configuration is shown in which all of the solenoid valves 2, 4, and 6 are connected to the receiver 108 via the block 10 (see Figure 1). In a modified example, the solenoid valves 2 and 6 may be connected to the receiver 108 via the block, and the solenoid valve 4 may be connected directly to the receiver 108. That is, the multiple control valves constituting the valve unit 1 may include control valves connected to the upper end member 52 of the receiver 108 via the block and control valves connected directly to the upper end member 52.

[0069] Alternatively, the solenoid valve 2 and the motorized valve 6 may be connected to the receiver 108 via the first block, and the solenoid valve 4 may be directly connected to the receiver 108 via the second block. The second block may be smaller than the first block. That is, the control valves constituting the valve unit 1 may include control valves connected to the upper end member 52 of the receiver 108 via the first block and control valves connected to the upper end member 52 via the second block.

[0070] It should be noted that the present invention is not limited to the embodiments and modifications described above, and the components can be modified and implemented without departing from the spirit of the invention. Various inventions may be formed by appropriately combining the multiple components disclosed in the embodiments and modifications described above. In addition, some components may be deleted from all the components shown in the embodiments and modifications described above. [Explanation of symbols]

[0071] 1 Valve unit, 2 Solenoid valve, 4 Solenoid valve, 6 Motorized valve, 10 Block, 20 Tank, 30 Body, 32 Drive unit, 40 Body, 42 Drive unit, 50 Tank, 52 Upper end member, 54 Lower end member, 56 Filter member, 70 Joint, 72 Joint, 74 Joint, 76 Joint, 78 Joint, 80 Seal ring, 100 Air conditioning system, 102 Compressor, 104 Auxiliary condenser, 106 Outdoor heat exchanger, 108 Receiver, 110 Evaporator, 114 Motorized valve, 116 On / off valve, 131 First flow path, 132 Second flow path, 133 Third flow path, 140 First inlet port, 142 First outlet port, 144 Second inlet port, 146 Second outlet port, 148 Discharge pipe, 150 Check valve, 152; Check valve, 158; Valve body, 160; Seal ring.

Claims

1. A valve unit applied to a refrigeration cycle comprising a first refrigerant circulation passage that is opened during cooling operation and a second refrigerant circulation passage that is opened during heating operation, A receiver that separates the refrigerant flowing through the first refrigerant circulation passage into gas and liquid during cooling operation, and separates the refrigerant flowing through the second refrigerant circulation passage into gas and liquid during heating operation, A block that is detachably mounted on the upper part of the receiver, Multiple control valves that are detachably assembled to the block and open and close the flow path formed in the block, Equipped with, The aforementioned receiver, A tank capable of storing refrigerant, An upper end member provided to close the upper end opening of the tank, A lower end member provided to close the lower end opening of the tank, Includes, The upper end member is provided with a first inlet port and a first outlet port that constitute the second refrigerant circulation passage, and the block is detachably attached. The lower end member is provided with a second inlet port and a second outlet port that constitute the first refrigerant circulation passage. The valve unit is characterized in that the receiver is equipped with a check valve that prevents backflow of refrigerant through the second inlet port.

2. The block has a first flow path that constitutes the first refrigerant circulation passage, a second flow path that constitutes the second refrigerant circulation passage and communicates with the first inlet port, and a third flow path that constitutes the second refrigerant circulation passage and communicates with the first outlet port. As the plurality of control valves, A first control valve is detachably assembled to the block and opens and closes the first flow path, A second control valve is detachably assembled to the aforementioned block and opens and closes the second flow path, A third control valve is detachably assembled to the aforementioned block and opens and closes the third flow path, The valve unit according to claim 1, characterized by comprising the above.

3. The valve unit according to claim 1 or 2, wherein the receiver has a filter for capturing foreign matter in the refrigerant and a desiccant for removing moisture from the refrigerant in the tank.

4. The valve unit according to claim 2, characterized in that the block comprises another check valve for preventing backflow of refrigerant in the third flow path.

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