CN113811725A

CN113811725A - Heat pump system

Info

Publication number: CN113811725A
Application number: CN201980093072.6A
Authority: CN
Inventors: 佐藤俊和
Original assignee: Izumi Corp
Current assignee: Izumi Corp
Priority date: 2019-02-26
Filing date: 2019-05-31
Publication date: 2021-12-17
Anticipated expiration: 2039-05-31
Also published as: JP2020139641A; WO2020174705A1; JP7330482B2; CN113811725B

Abstract

An object of the present invention is to provide a heat pump system in which a refrigerant control member is integrally formed in advance as a unit by piping, which can achieve cost performance due to compactness, and which can sufficiently cope with particularly extremely low temperatures. The heat pump system is characterized by comprising: a four-way switching valve unit (10) which, in correspondence with the switching of the cooling, heating and dehumidifying functions, enables the four refrigerant paths to be freely switched in pairs between two sets of paths; a gas injection unit (20) provided with a proportional control valve and a plurality of metal plates that can be laminated in a gas-tight manner; a liquid separation unit (30) that separates liquid; a cooling/heating control unit (40) which is provided with a plurality of metal plates that can be laminated in an airtight manner and which switches the cooling, heating, and dehumidifying functions; a condenser (50) for condensing the refrigerant or an evaporator (60) for expanding the refrigerant; and a compressor (70) that compresses the refrigerant.

Description

Heat pump system

Technical Field

The present invention relates to a heat pump system for an automotive air conditioner capable of handling a very low temperature specification in which the outdoor air temperature is very low.

Background

Cooling and heating of the internal combustion engine car can be performed depending on exhaust heat, and therefore, not only indoor heating, but also a defroster (hereinafter also referred to as "dehumidification heating") for removing condensation that occurs with heating, that is, blurring of the inner surface of the front windshield and ensuring a visual field can be configured relatively easily. This is because it is easy to ensure warm air based on heat removal utilization if in operation.

In the air-conditioning apparatus of the vehicle type using only the internal combustion engine for driving force, the air-conditioning apparatus is supplied by a compressor driven by an engine belt only for cooling, and the air-conditioning apparatus is only required to use exhaust heat for heating. Therefore, in the function of switching from cooling to heating and dehumidifying and heating, it is not necessary to reverse the direction of the refrigerant gas flowing through the refrigerant circuit, and the compressor dedicated for cooling is stopped and warm air for exhaust heat utilization is blown.

In recent years, the drive system of passenger vehicles has been changed from internal combustion engines to Electric Vehicles (EV), Fuel Cell Vehicles (FCV), and the like. In the case of a vehicle of a type that does not always start the internal combustion engine during operation, it is a natural trend to change the vehicle type to an electric type in the entire vehicle-mounted auxiliary system including an air conditioner.

In accordance with this trend, a compressor of an automotive air conditioner is changed from a belt-mounted drive to a motor-driven compressor, and is widely used. In addition, among Electric Vehicles (EVs), there are Plug-in Hybrid cars (Plug-in Hybrid cars), i.e., PHVs (Plug-in Hybrid vehicles) or PHEVs (Plug-in Hybrid Electric vehicles). A PHEV is a hybrid vehicle that can directly charge a battery using a plug inserted from a socket.

In addition, not limited to the vehicle air conditioner used in the Electric Vehicle (EV), the Fuel Cell Vehicle (FCV), and the like, but in a cooling and heating dual-purpose air conditioner based on a general reversible heat pump cycle for housing use, when the functions of cooling and heating are switched, it is necessary to reverse the direction in which a refrigerant gas such as freon (hereinafter also simply referred to as "refrigerant") flows in a refrigerant circuit. On the other hand, in a compressor for compressing a refrigerant and causing the refrigerant to flow in a refrigerant circuit, generally, the direction of input and output is constant. That is, a general compressor cannot reverse the suction port and the discharge port. Therefore, in order to reverse the direction of the refrigerant gas flowing through the refrigerant circuit, it is necessary to switch the piping of the refrigerant circuit by the four-way valve.

On the other hand, in the case of an Electric Vehicle (EV), a Fuel Cell Vehicle (FCV), or the like, heating by use of exhaust heat is unreliable and difficult to adopt. Although not necessary for the residential air conditioner, the automobile air conditioner is indispensable for a defroster (dehumidification and heating). The defroster is provided with a condenser and a dehumidification valve, which are arranged in the vicinity of a condenser generating heat for indoor heating and generate low temperature for dehumidification and condensation, and functions by throttling the dehumidification valve.

Therefore, air conditioning apparatuses such as Electric Vehicles (EV) and Fuel Cell Vehicles (FCV) are considerably complicated in terms of electromagnetic valves for switching between these valves and pipes leading to these valves (hereinafter also referred to as "four-way valve peripheral portion") in addition to the four-way valve and the dehumidification valve. Moreover, even a control function of controlling a plurality of solenoid valves is required.

Further, even if the air conditioner is not a vehicle air conditioner having a main motor, the air conditioner is relatively large and heavy, and therefore, in particular, the air conditioner for a vehicle is required to be small, light, and thin. In addition to the small size, light weight, and thin profile, there is a demand for an excellent assembly workability, an improvement in productivity, and a reduction in manufacturing cost. In order to meet such a demand, the following techniques are disclosed.

A piping unit (hereinafter, also simply referred to as "piping unit") of a heat pump refrigerator, in which a refrigerant control member is integrally piping and unitized in advance, is known (for example, patent document 1). That is, the refrigerant control means of the refrigeration cycle (refrigerant circuit) of the heat pump refrigerator (heat pump apparatus) is integrally piping and unitized in advance, piping components and piping welded portions are reduced, assembly workability is excellent, productivity is improved, manufacturing cost is reduced, and the outdoor unit is reduced in size and thickness.

The piping unit described in patent document 1 is a piping unit including: the refrigerant control member is integrally attached to the base plate by a refrigerant passage pipe, and a pipe port connected to the refrigerant passage is disposed in the refrigerant passage.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 7-198229

Disclosure of Invention

Problems to be solved by the invention

However, the piping unit described in patent document 1 is not a piping unit for vehicle mounting. In addition, when the outdoor air is at an extremely low temperature, sufficient heating, dehumidifying and heating functions cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat pump system in which a refrigerant control member can be integrally formed in advance in a piping and unitized manner, which can achieve cost performance due to compactness, and which can sufficiently cope with particularly extremely low temperatures.

Means for solving the problems

A heat pump system according to an aspect of the present invention is a heat pump system for an extremely low temperature specification, the heat pump system including: a four-way switching valve unit which, in correspondence with the switching of the cooling, heating and dehumidifying functions, switches the four refrigerant paths in pairs between the two sets of paths; a gas injection unit provided with a proportional control valve and a plurality of metal plates which can be laminated in a gas-tight manner; a liquid separation unit that separates liquid; a cooling/heating control unit that is provided with a plurality of metal plates that can be laminated in an airtight manner and switches the cooling, heating, and dehumidifying functions; a condenser that condenses the refrigerant or an evaporator that expands the refrigerant; and a compressor that compresses the refrigerant, the four-way switching valve unit flowing the refrigerant in from the cooling/heating control unit and flowing out to the liquid separation unit and flowing the refrigerant in from the compressor and flowing out to a condenser, or flowing the refrigerant in from the condenser and flowing out to the liquid separation unit and flowing in from the compressor and flowing out to the cooling/heating control unit, the gas injection unit flowing the refrigerant in from the condenser and flowing out to the compressor and/or flowing out to the cooling/heating control unit or the evaporator by the proportional control valve, or flowing the refrigerant in from the evaporator and flowing out to the condenser, the liquid separation unit flowing the refrigerant in from the four-way switching valve unit and flowing out to the compressor, the cooling/heating control unit causes the refrigerant to flow in from the gas injection unit and flow out to the four-way switching valve unit, or to flow in from the four-way switching valve unit and flow out to the gas injection unit.

In this case, in one aspect of the present invention, the four-way switching valve unit and the liquid separation unit may be integrated, a pipe end of the compressor may be configured by two pipe ends that flow in from the gas injection unit and flow in from the liquid separation unit through the proportional control valve, and one pipe end that flows out to the four-way switching valve unit, and the gas injection unit may flow in the refrigerant from the condenser and flow out to the compressor and flow out to the cooling/heating control unit or the evaporator by the proportional control valve.

In this case, in one aspect of the present invention, the four-way switching valve unit and the liquid separation unit may be integrated, a pipe end of the compressor may be configured by one pipe end through which the refrigerant flows from the liquid separation unit and one pipe end through which the refrigerant flows out to the four-way switching valve unit, the gas injection unit may flow the refrigerant into a pipe end of a gas phase provided in the liquid separation unit, and the liquid separation unit may flow the refrigerant out to the cooling/heating control unit or the evaporator through the gas injection unit.

In this case, in one aspect of the present invention, the four-way switching valve unit may be separated from the liquid separation unit, and the pipe ends of the compressor may be configured by two pipe ends through which the refrigerant flows into the gas injection unit and the refrigerant flows into the liquid separation unit, and one pipe end through which the refrigerant flows out of the four-way switching valve unit.

In this case, in one aspect of the present invention, in the heat pump system, the four-way switching valve unit may further include a check valve and a cooling expansion valve, the four-way switching valve unit may be separated from the liquid separation unit, the pipe end of the compressor may be configured by one pipe end through which the refrigerant flows into the four-way switching valve unit from the liquid separation unit and one pipe end through which the refrigerant flows out of the four-way switching valve unit, and the gas injection unit may be configured to flow the refrigerant into a pipe end of a gas phase provided in the liquid separation unit.

In this case, according to an aspect of the present invention, the four-way switching valve unit may include: a first connection port through which the refrigerant flows in and out; a cylinder to which the refrigerant is supplied from the connection port; a spool formed in a chevron shape, provided in the cylinder, and movable in an axial direction of the cylinder so as to be connectable in one of two modes; and a second connection port through which the refrigerant passes through the spool and into and out of the second connection port, wherein a convex portion is provided on a top surface of the spool, and a concave portion for receiving the convex portion is provided on an inner surface of the cylinder.

In this case, according to an aspect of the present invention, the spool may include: a spool head formed of metal in a chevron shape; and a base of teflon (registered trademark) that fixes the spool head.

In this case, in one aspect of the present invention, a plurality of metal plates may be stacked on the second connection port, the metal plates may be composed of a lower plate, an intermediate plate, and an upper plate, through holes may be formed to allow the refrigerant to flow therethrough, and the through holes of the lower plate, the intermediate plate, and the upper plate may have a diameter larger than that of the second connection port.

In this case, in one aspect of the present invention, a partition base formed by stacking two or more metal plates or a partition base formed integrally may be further provided on the plurality of metal plates that can be stacked while maintaining airtightness, which constitute the gas injection unit and the cooling/heating control unit.

In this case, according to one aspect of the present invention, the heat pump system may further include a vertical check valve including: an outer cylinder; an inner cylinder provided inside the outer cylinder; a valve provided at the bottom of the inner cylinder and allowing the refrigerant to flow in and not allowing the refrigerant to flow out; and a port provided on a side surface of the inner tube and through which the refrigerant flows out.

In this case, in one aspect of the present invention, the heat pump system may further include one or more of a heating expansion valve, a dehumidifying expansion valve, and a cooling expansion valve, and the heating expansion valve, the dehumidifying expansion valve, and the cooling expansion valve may include: a main body portion; a pillar provided in the main body; a magnet and a pulse motor fixed to the column so that the column can move in an up-down direction to adjust a flow rate of the refrigerant; a stopper fixed to the main body; and an upper stopper and a lower stopper which prevent the pillar from being excessively moved in the vertical direction, the pillar being formed with a groove in which the upper stopper and the lower stopper can be mounted.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a heat pump system in which a refrigerant control member is integrally formed in advance as a unit by piping, which can achieve cost performance due to compactness, and which can sufficiently cope with particularly extremely low temperatures.

Drawings

Fig. 1 is a schematic diagram of a heat pump system according to an embodiment of the present invention, and is a schematic diagram of a heat pump system in a case where a four-way switching valve unit and a liquid separation unit are combined.

Fig. 2 is a schematic diagram of a heat pump system according to an embodiment of the present invention, and is a schematic diagram of a heat pump system in a case where the four-way switching valve unit is separated from the liquid separation unit.

Fig. 3 is an explanatory diagram of a refrigerant circuit of the type a heat pump system according to the embodiment of the present invention during heating.

Fig. 4 is an explanatory diagram of a refrigerant circuit of the type a heat pump system in the dehumidification heating mode according to the embodiment of the present invention.

Fig. 5 is an explanatory diagram of a refrigerant circuit of type a of the heat pump system in refrigeration according to the embodiment of the present invention.

Fig. 6 is an explanatory diagram of a refrigerant circuit of a type B heat pump system according to an embodiment of the present invention during heating.

Fig. 7 is an explanatory diagram of a refrigerant circuit in the case of type B dehumidification-heating of the heat pump system according to the embodiment of the present invention.

Fig. 8 is an explanatory diagram of a refrigerant circuit of type B of the heat pump system in refrigeration according to the embodiment of the present invention.

Fig. 9 is an explanatory diagram of a refrigerant circuit of type C of the heat pump system according to the embodiment of the present invention during heating.

Fig. 10 is an explanatory diagram of a refrigerant circuit in the case of type C dehumidification-heating of the heat pump system according to the embodiment of the present invention.

Fig. 11 is an explanatory diagram of a refrigerant circuit of type C of the heat pump system in refrigeration according to the embodiment of the present invention.

Fig. 12 is an explanatory diagram of a refrigerant circuit of the heat pump system of the embodiment of the present invention in the heating mode of type D.

Fig. 13 is an explanatory diagram of a refrigerant circuit in dehumidification heating of type D of the heat pump system according to the embodiment of the present invention.

Fig. 14 is an explanatory diagram of a refrigerant circuit of type D of the heat pump system in refrigeration according to the embodiment of the present invention.

Fig. 15 is a perspective view of a gas injection unit for a heat pump system of an embodiment of the present invention.

Fig. 16 is a schematic view of a plurality of stacked metal plates and a partition base provided in a gas injection unit, fig. 16 (a) is a plan view of the metal plates, fig. 16 (B) is a sectional view a-a of the metal plates, and fig. 16 (C) is a sectional view B-B.

Fig. 17 is a schematic view of an upper plate constituting a plurality of stacked metal plates provided in the gas injection unit, fig. 17 (a) is a plan view of the upper plate, and fig. 17 (B) is a side view of the upper plate.

Fig. 18 is a schematic view of a first intermediate plate constituting a plurality of stacked metal plates provided in the gas injection unit, fig. 18 (a) is a plan view of the first intermediate plate, and fig. 18 (B) is a side view of the first intermediate plate.

Fig. 19 is a schematic view of a second intermediate plate constituting a plurality of stacked metal plates provided in the gas injection unit, fig. 19 (a) is a plan view of the second intermediate plate, and fig. 19 (B) is a side view of the second intermediate plate.

Fig. 20 is a schematic view of a lower plate constituting a plurality of laminated metal plates provided in the gas injection unit, fig. 20 (a) is a plan view of the lower plate, and fig. 20 (B) is a side view of the lower plate.

Fig. 21 is a perspective view of a cooling/heating control unit used in the heat pump system according to the embodiment of the present invention.

Fig. 22 is a schematic view of a plurality of laminated metal plates and a partition base provided in the cooling/heating control unit, fig. 22 (a) is a plan view of the metal plates, fig. 22 (B) is a C-C sectional view of the metal plates, and fig. 22 (C) is a D-D sectional view.

Fig. 23 is a perspective view of a four-way switching valve unit used in a heat pump system according to an embodiment of the present invention, fig. 23 (a) is a perspective view of the four-way switching valve unit used in a case where the four-way switching valve unit and a liquid separation unit are combined, fig. 23 (B) is a perspective view of a plurality of stacked metal plates provided at a lower portion of the four-way switching valve unit and viewed from a bottom surface of fig. 23 (a), and fig. 23 (C) is a perspective view of the four-way switching valve unit used in a case where the four-way switching valve unit and the liquid separation unit are separated, and a stacked metal plate is further provided at a lower portion of the four-way switching valve unit.

Fig. 24 is a schematic view of a cylindrical body provided in the four-way switching valve unit, fig. 24 (a) is a perspective view of the cylindrical body, fig. 24 (B) is a cross-sectional view of a side surface of the cylindrical body, and fig. 24 (C) is a cross-sectional view a-a of fig. 24 (B).

Fig. 25 is a schematic diagram of the four-way switching valve unit, fig. 25 (a) is a view seen from the bottom of fig. 23 (a), and fig. 25 (B) is a cross-sectional view taken along line a-a of fig. 25 (a).

Fig. 26 is a sectional view of a proportional control valve provided in a gas injection unit.

Fig. 27 is a cross-sectional view of the check valve.

Fig. 28 is a sectional view of the expansion valve for heating, the expansion valve for dehumidification, and the expansion valve for cooling.

Detailed Description

A heat pump system 100 according to an embodiment of the present invention will be described below with reference to the drawings. The heat pump system 100 according to an embodiment of the present invention is a heat pump system for an extremely low temperature specification of an automobile air conditioner. As shown in fig. 1, the heat pump system 100 includes: a four-way switching valve unit 10 that, in response to switching of the cooling, heating, and dehumidifying functions, switches the four refrigerant paths in pairs between two sets of paths; a gas injection unit 20 provided with a proportional control valve 22 and a plurality of metal plates 25 which can be laminated in a gas-tight manner; a liquid separation unit 30 that separates liquid; a cooling/heating control unit 40 that is provided with a plurality of metal plates 45 that can be laminated in an airtight manner, and switches the cooling, heating, and dehumidifying functions; a condenser 50 for condensing the refrigerant or an evaporator 60 for expanding the refrigerant; and a compressor 70 for compressing the refrigerant.

According to the heat pump system 100 of the embodiment of the present invention, the refrigerant control means is integrally formed in advance as a unit by piping as described later, and cost performance can be achieved by making the system compact. Further, by further compressing the medium-temperature and medium-pressure refrigerant by the compressor and sending the compressed refrigerant to the condenser 50 by the proportional control valve 22 provided in the gas injection unit 20, warm air at a higher temperature can be obtained, and particularly, extremely low temperatures can be sufficiently coped with. The following description is made.

In fig. 1, the arrows of broken lines indicate the direction of flow of the refrigerant during heating, the circles of broken lines indicate the direction of flow of the refrigerant during dehumidification-heating, and the arrows of solid lines indicate the direction of flow of the refrigerant during cooling. The direction of flow of each refrigerant differs during heating, dehumidification heating, and cooling. The same applies to fig. 2 described later.

The flows of the refrigerants from the four-way switching valve unit 10, the gas injection unit 20, the liquid separation unit 30, and the cooling/heating control unit 40 included in the heat pump system 100 according to the embodiment of the present invention at the time of heating, the time of heating by dehumidification, and the time of cooling will be described.

The four-way switching valve unit 10 allows the refrigerant to flow in from the cooling/heating control unit 40 and flow out to the liquid separation unit 30 and allows the refrigerant to flow in from the compressor 70 and flow out to the condenser 50 through the four-way switching valve unit 10 during heating or dehumidification heating, and allows the refrigerant to flow in from the condenser 50 and flow out to the liquid separation unit 30 through the four-way switching valve unit 10 and allows the refrigerant to flow in from the compressor 70 and flow out to the cooling/heating control unit 40 during cooling.

The gas injection unit 20 allows the refrigerant to flow into the condenser 50 and to flow out to the compressor 70 and/or to the cooling/heating control unit 40 or the evaporator 60 by the proportional control valve 22 during heating or dehumidification heating. During cooling, the refrigerant flows into the evaporator 60 and flows out to the condenser 50.

The liquid separation unit 30 allows the refrigerant to flow into the four-way switching valve unit 10 and flow out to the compressor 70 during heating, dehumidifying heating, and cooling.

The cooling/heating control unit 40 causes the refrigerant to flow in from the gas injection unit 20 and flow out to the four-way switching valve unit 10 during heating or dehumidification heating. During cooling, the refrigerant flows in from the four-way switching valve unit 10 and flows out to the gas injection unit 20.

The four-way switching valve unit 10, the gas injection unit 20, the liquid separation unit 30, and the cooling/heating control unit 40 are provided with pipe ends. The refrigerant is flowed into and out of each apparatus through the pipe end. The manifold can be provided to make the unit and compact. As shown in fig. 1 and 2, the gas injection unit 20 is preferably provided with a heating expansion valve 26, a dehumidification expansion valve 23, a first check valve 24, and a second check valve 27, and is used in accordance with a refrigerant circuit at the time of heating, dehumidification heating, or cooling. Similarly, the cooling/heating control unit 40 is preferably provided with a check valve 41, an expansion valve 42 for cooling, and an expansion valve 43 for battery, and is used in accordance with the refrigerant circuit at the time of heating, dehumidification heating, or cooling. These are connected via the pipe ends and allow the refrigerant to flow therethrough.

As shown in fig. 1 and 2, the heating expansion valve 26, the dehumidification expansion valve 23, the first check valve 24, the second check valve 27, the check valve 41, the cooling expansion valve 42, and the battery expansion valve 43 are in contact with the partition bases 28 and 48 formed by stacking two or more metal plates on top of the plurality of

metal plates

25 and 45 that can be stacked while maintaining airtightness and that constitute the gas injection unit 20 and the cooling/heating control unit 40. The partition bases 28 and 48 formed by stacking two or more metal plates can also be stacked in an airtight manner. The structure of the partition bases 28, 48 will be described later.

The heat pump system 100 of one embodiment of the present invention can be broadly classified into A, B, C, D of four types. Each type will be described later using fig. 3 to 14 of the refrigerant circuit explanatory diagram.

The type a is a heat pump system in the case where the four-way switching valve unit 10 and the liquid separation unit 30 are combined as shown in fig. 1. The piping ends of the compressor 70 are composed of two piping ends flowing in from the gas injection unit 20 and flowing in from the liquid separation unit 30 via the proportional control valve 22 and one piping end flowing out to the four-way switching valve unit 10, that is, the piping ends of the compressor 70 have three ports. In addition, the gas injection unit 20 causes the refrigerant to flow in from the condenser 50 and to flow out to the compressor 70 and to flow out to the cooling/heating control unit 40 or the evaporator 60 by the proportional control valve 22.

The type B is also a heat pump system in the case where the four-way switching valve unit 10 and the liquid separation unit 30 are combined as shown in fig. 1, but is characterized in that the pipe ends of the compressor 70 are constituted by one pipe end into which the refrigerant flows from the liquid separation unit 30 and one pipe end from which the refrigerant flows out to the four-way switching valve unit 10, that is, the pipe ends of the compressor 70 are two ports, which is different from the type a. The gas injection unit 20 causes the refrigerant to flow into a gas-phase pipe end provided in the liquid separation unit 30, and the liquid separation unit 30 causes the refrigerant to flow out to the cooling/heating control unit 40 or the evaporator 60 through the gas injection unit 20.

The type C is a heat pump system in the case where the four-way switching valve unit 10 is separated from the liquid separation unit 30 as shown in fig. 2. The piping ends of the compressor 70 are composed of two piping ends for allowing the refrigerant to flow into the gas injection unit 20 and the refrigerant to flow into the liquid separation unit 30, and one piping end for allowing the refrigerant to flow out to the four-way switching valve unit 10, that is, the piping ends of the compressor 70 have three ports. The pipe ends of the compressor 70 are configured by two pipe ends through which the refrigerant flows in from the gas injection unit 20 and the refrigerant flows in from the liquid separation unit 30, and one pipe end through which the refrigerant flows out to the four-way switching valve unit 10.

Type D is also a heat pump system in the case where the four-way switching valve unit 10 is separated from the liquid separation unit 30 as shown in fig. 2. The type D is characterized in that the four-way switching valve unit 10 is further provided with a check valve and a cooling expansion valve (not shown in fig. 1) to form a refrigerant circuit without using the cooling/heating control unit 40. The refrigerant circuit will be described later. The piping ends of the compressor 70 are configured by one piping end for flowing the refrigerant from the liquid separation unit 30 and one piping end for flowing the refrigerant to the four-way switching valve unit 10, that is, the piping ends of the compressor 70 are two ports. The gas injection unit 20 causes the refrigerant to flow into the end of the gas-phase pipe provided in the liquid separation unit 30.

Next, the refrigerant circuits of the A, B, C, D type at the time of heating, the time of dehumidification-heating, and the time of cooling will be described in order using the refrigerant circuit explanatory diagrams.

First, the type a refrigerant circuit will be explained. Fig. 3 is an explanatory diagram of a refrigerant circuit of the type a heat pump system 100 according to the embodiment of the present invention during heating. The solid line indicates a circuit through which the refrigerant passes in the figure, and the broken line indicates a circuit through which the refrigerant does not pass. The refrigerant circuits that flow during heating, dehumidification heating, and cooling are different, and therefore are indicated by solid lines or broken lines. The arrows are the direction of flow of the refrigerant. These are the same as the explanatory views of the refrigerant circuit shown in fig. 4 to 14. In the refrigerant circuit of the heating circuit of fig. 3, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the heating expansion valve 26 has a high temperature and a high pressure (the refrigerant in the path from the compressor 70 to the condenser 50 has a higher temperature and a higher pressure, which will be described later). Intermediate temperature and pressure from the outlet of the proportional control valve 22 to the compressor 70. On the other hand, the refrigerant in the path from the heating expansion valve 26 of the gas injection unit 20, through the cooling/heating control unit 40, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30, and entering the compressor 70 becomes low-temperature and low-pressure. The compressor 70 has a three-port pipe end.

As described above, the four-way switching valve unit 10 and the liquid separation unit 30 are integrated in the type a. By the combination, the refrigerant flow path can be shortened, and the piping resistance can be reduced. Further, the four-way switching valve unit 10 and the liquid separation unit 30 can be reduced in the number of suction pipes, which can reduce the cost, and the number of pipes can be reduced to save space.

As shown in fig. 3, the four-way switching valve unit 10 causes the refrigerant to flow from the cooling/heating control unit 40 into the outdoor condenser 110 and to flow out to the liquid separation unit 30. The four-way switching valve unit 10 allows the refrigerant to flow into the compressor 70 and flow out to the condenser 50.

The four-way switching valve unit 10 can be connected so that the four refrigerant paths U, V, W, X are divided into two sets of paths in pairs. The four-way selector valve unit 10 is switchable between two connection modes, i.e., UV, WX, WU, and XV. For example, as shown in fig. 3 and the like, in the first embodiment, the refrigerant path U and the refrigerant path V communicate with each other, while the refrigerant path W and the refrigerant path X communicate with each other. On the other hand, as shown in fig. 5 and the like, in the second embodiment, the refrigerant path W and the refrigerant path U are communicated with each other, while the refrigerant path X and the refrigerant path V are communicated with each other. The structure of the four-way switching valve unit 10 will be described in detail later.

The gas injection unit 20 causes the refrigerant to flow into the condenser 50, and causes a part of the refrigerant to flow out to the compressor 70 by the proportional control valve 22 without completely flowing out to the cooling/heating control unit 40, and causes a part of the refrigerant to flow out to the cooling/heating control unit 40 at the same time. The refrigerant changes to a high temperature and a high pressure in the path from the compressor 70 to the compressor 70 through the four-way switching valve unit 10, the condenser 50, and the gas injection unit 20, but when the refrigerant does not completely enter the cooling/heating control unit 40, the refrigerant is expanded to a medium temperature and a medium pressure by the proportional control valve 22 provided in the gas injection unit 20 and then enters the compressor 70, so that the refrigerant can be further compressed by the compressor, the outflow amount of the refrigerant having a higher temperature and a higher pressure from the compressor 70 increases, the path from the compressor 70 to the four-way switching valve unit 10 and the condenser 50 changes to a high temperature and a high pressure refrigerant, and the capacity of the condenser 50 improves. Therefore, by sending the refrigerant to the condenser 50 and blowing it by the blower 120, warm air of a higher temperature can be obtained, and particularly, extremely low temperature can be sufficiently coped with.

In addition, the amount of refrigerant flowing out to the compressor 70 or the cooling/heating control unit 40 is adjusted by the proportional control valve 22 provided in the gas injection unit 20 according to the temperature setting in the vehicle. For example, when the temperature in the vehicle is set to a higher temperature, the amount of the refrigerant to be sent from the gas injection unit 20 to the compressor 70 may be increased, and when the temperature is set to a lower temperature, the amount of the refrigerant to be sent to the compressor 70 may be decreased.

The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70. The cooling and heating control unit 40 causes the refrigerant to flow in from the gas injection unit 20 and to flow out to the four-way switching valve unit 10 through the outdoor condenser 110. The gas injection unit 20 and the cooling/heating control unit 40 of the type a heating circuit, the dehumidification heating circuit, and the refrigeration circuit are independent. The liquid separation unit 30 is a unit provided with a function of separating gas and liquid, and functions to recover refrigerant and the like.

It is preferable that the gas injection means 20 is provided with the dehumidification expansion valve 23, the first check valve 24, the second check valve 27, and the heating expansion valve 26, and the cooling/heating control means 40 is provided with the check valve 41, the cooling expansion valve 42, and the battery expansion valve 43, so that switching between heating, dehumidification heating, and cooling is performed. B. C, D are also of the same type.

Fig. 4 is an explanatory diagram of a refrigerant circuit of the type a heat pump system 100 in the dehumidification heating mode according to the embodiment of the present invention. In the refrigerant circuit of the dehumidification-air heating circuit of fig. 4, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the expansion valve 23 for dehumidification becomes high-temperature and high-pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher-temperature and higher-pressure). Intermediate temperature and pressure from the outlet of the proportional control valve 22 to the compressor 70. On the other hand, the refrigerant in the path from the dehumidification expansion valve 23 of the gas injection unit 20 to the compressor 70 via the evaporator 60, the cooling/heating control unit 40, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30 is at a low temperature and a low pressure.

The four-way switching valve unit 10 causes the refrigerant to flow from the cooling/heating control unit 40 into the outdoor condenser 110 and to flow out to the liquid separation unit 30. The four-way switching valve unit 10 allows the refrigerant to flow into the compressor 70 and flow out to the condenser 50.

The gas injection unit 20 causes the refrigerant to flow in from the condenser 50 and to flow out to the compressor 70 using the proportional control valve 22. At the same time, the air flows out to the cooling/heating control unit 40 through the evaporator 60. As described above, since the refrigerant is expanded to the intermediate temperature and pressure by the proportional control valve 22 provided in the gas injection unit 20 and then enters the compressor 70, the refrigerant can be further compressed by the compressor, the outflow amount of the refrigerant having the higher temperature and pressure from the compressor 70 is increased, the refrigerant becomes the high temperature and pressure refrigerant in the path from the compressor 70 to the four-way switching valve unit 10 and the condenser 50, and the capacity of the condenser 50 is improved. On the other hand, the low-temperature refrigerant expanded by the expansion valve for dehumidification 23 flows into the (indoor) evaporator 60, and the dehumidification of the vehicle interior glass window can be performed quickly.

The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70. The cooling/heating control unit 40 causes the refrigerant to flow in from the gas injection unit 20, pass through the outdoor condenser 110, and flow out to the four-way switching valve unit 10.

Fig. 5 is an explanatory diagram of a refrigerant circuit of the type a of the heat pump system 100 in refrigeration according to the embodiment of the present invention. In the refrigerant circuit of the refrigeration circuit of fig. 5, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the outdoor condenser 110, and the cooling/heating control unit 40 has a high temperature and a high pressure. On the other hand, the refrigerant in a path from the cooling/heating control unit 40, through the evaporator 60, the gas injection unit 20, the condenser 50, the four-way switching valve unit 10, and the liquid separation unit 30, and entering the compressor 70 becomes low-temperature and low-pressure.

The four-way switching valve unit 10 causes the refrigerant to flow in from the condenser 50 and to flow out to the liquid separation unit 30. The refrigerant flows into the compressor 70, passes through the outdoor condenser 110, and flows out to the cooling/heating control unit 40.

The gas injection unit 20 causes the refrigerant to flow in from the evaporator 60 and flow out toward the condenser 50.

The cooling/heating control unit 40 causes the refrigerant to flow from the four-way switching valve unit 10 into the outdoor condenser 110 and to flow out to the gas injection unit 20. Further, as shown in fig. 5, the battery inverter cooler 130 may be provided so that the refrigerant flows in from the cooling/heating control unit 40 and flows out to the gas injection unit 20. The cooling function is further improved if it is set as such.

In the refrigeration circuit, the high-temperature and high-pressure refrigerant circuit from the outdoor condenser 110 is integrated with the battery expansion valve 43 through the cooling expansion valve 42 provided in the cooling/heating control unit 40, and thus compactness and workability can be improved.

Next, a description will be given of the type B refrigerant circuit. Fig. 6 is an explanatory diagram of a refrigerant circuit of the type B heat pump system 100 according to the embodiment of the present invention during heating. In the refrigerant circuit of the heating circuit of fig. 6, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the heating expansion valve 26 becomes high in temperature and pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher in temperature and pressure). The intermediate temperature and pressure is from the outlet of the proportional control valve 22 through the liquid separation unit 30 to the compressor 70. On the other hand, the refrigerant in the path from the heating expansion valve 26 of the gas injection unit 20, through the cooling/heating control unit 40, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30, and entering the compressor 70 becomes low-temperature and low-pressure.

In the heating circuit, the high-temperature and high-pressure refrigerant from the condenser 50 is expanded at a medium temperature by the

proportional control valve

22, and 100% of the humidified gas flows into the liquid separation unit 30. The gas (refrigerant) having a large specific gravity flows into the condenser 50 from the gas phase separated into two phases in the liquid separation unit 30.

As for the refrigerant in the path shown in fig. 6, the medium-temperature and medium-pressure refrigerant from the condenser 50 is sent to the gas phase side of the liquid separation unit 30 and flows into the compressor 70, is compressed by the compressor 70 and flows out to the condenser 50, and thus a higher-temperature and high-pressure refrigerant is obtained. At this time, the refrigerant in the path immediately before the compressor 70, the four-way switching valve unit 10, the condenser 50, and the proportional expansion valve 22 of the gas injection unit 20 is at a high temperature and a high pressure (liquefied). On the other hand, the refrigerant expanded by the proportional expansion valve 22 and having an intermediate temperature and an intermediate pressure flows into the liquid separation unit 30. The medium-temperature and medium-pressure refrigerant flowing into the liquid separation unit 30 is separated into two phases of a gas phase and a liquid phase by a difference in specific gravity in the liquid separation unit 30, and the medium-temperature and medium-pressure refrigerant gas in the liquid phase portion flows into the compressor 70, so that the capacity of the condenser 50 is improved. On the other hand, the liquid-phase portion refrigerant (liquefied) in the liquid separation unit 30 flows into the heating expansion valve 26, expands again, and flows into the cooling/heating control unit 40.

When the medium-temperature and medium-pressure refrigerant is sent from the condenser 50 to the gas phase side of the liquid separation unit 30, it is preferable that the pipes in the liquid separation unit 30 are provided so that the refrigerant is in contact with the wall surface of the liquid separation unit 30, without flowing vertically (directly below) the refrigerant. When the refrigerant is brought into contact with the wall surface of the liquid separation unit 30, it is preferable to provide a socket for bending the refrigerant in a right angle direction at a portion to be sent to the gas phase side of the liquid separation unit 30. If provided in this manner, the refrigerant is prevented from being directly discharged into the liquid phase in the liquid separation unit 30, and therefore, a backflow phenomenon (bubbling) in the liquid separation unit 30 can be prevented.

The gas injection unit 20 causes the refrigerant to flow from the condenser 50, and flows out to the compressor 70 through the liquid separation unit 30 by the proportional control valve 22 and/or flows out to the cooling/heating control unit 40 through the heating expansion valve 26.

The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70. The medium-temperature and medium-pressure refrigerant located in the lower stage of the liquid separation unit 30 is re-expanded by the heating expansion valve 26 provided in the gas injection unit 20, passes through the check valve 41 provided in the cooling/heating control unit 40, and flows out to the liquid separation unit 30 through the outdoor condenser 110.

The cooling and heating control unit 40 causes the refrigerant to flow in from the gas injection unit 20 and to flow out to the four-way switching valve unit 10 through the outdoor condenser 110. The gas injection unit 20 and the cooling/heating control unit 40 of the B-type heating circuit, the dehumidification heating circuit, and the refrigeration circuit are independent.

Fig. 7 is an explanatory diagram of a refrigerant circuit of the type B heat pump system 100 according to the embodiment of the present invention during the dehumidification-air heating. In the refrigerant circuit of the dehumidification-heating circuit of fig. 7, the refrigerant flowing from the compressor 70 to the inlet of the four-way switching valve unit 10, the condenser 50, and the proportional control valve 22 of the gas injection unit 20 has a high temperature and a high pressure (the refrigerant in the path from the compressor 70 to the condenser 50 has a higher temperature and a higher pressure). The refrigerant from the outlet of the dehumidification expansion valve 23 of the proportional control valve 22 passes through the liquid separation unit 30, and reaches the inlet of the dehumidification expansion valve 23 of the gas injection unit 20 at the intermediate temperature and the intermediate pressure. On the other hand, the refrigerant from the outlet of the dehumidification expansion valve 23 of the gas injection unit 20 to the evaporator 60 and the cooling/heating control unit 40 becomes low-temperature and low-pressure.

In the refrigerant circuit at the time of the type B heating by dehumidification, it is different from the refrigerant circuit at the time of heating in that the gas injection unit 20 causes the refrigerant to flow in from the condenser 50 and to flow out to the compressor 70 and/or to flow out to the evaporator 60 by using the proportional control valve 22. Otherwise, the same as the refrigerant circuit in heating of type B described above.

Fig. 8 is an explanatory diagram of a refrigerant circuit of the type B heat pump system 100 according to the embodiment of the present invention during cooling. In the refrigerant circuit of the refrigeration circuit of fig. 8, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the outdoor condenser 110, and the cooling/heating control unit 40 has a high temperature and a high pressure. On the other hand, the refrigerant in a path from the cooling/heating control unit 40, through the evaporator 60, the gas injection unit 20, the condenser 50, the four-way switching valve unit 10, and the liquid separation unit 30, and entering the compressor 70 becomes low-temperature and low-pressure.

The four-way switching valve unit 10 causes the refrigerant to flow in from the condenser 50 and to flow out to the liquid separation unit 30 and causes the refrigerant to flow in from the compressor 70 and to flow out to the cooling and heating control unit 40 through the outdoor condenser 110.

The gas injection unit 20 causes the refrigerant to flow in from the evaporator 60 and flow out toward the condenser 50. The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70. The cooling/heating control unit 40 causes the refrigerant to flow from the four-way switching valve unit 10 into the outdoor condenser 110 and to flow out to the gas injection unit 20.

Next, a refrigerant circuit of type C will be explained. Fig. 9 is an explanatory diagram of a refrigerant circuit of the heat pump system 100 of the type C during heating according to the embodiment of the present invention. In the refrigerant circuit of the heating circuit of fig. 9, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the heating expansion valve 26 becomes high in temperature and pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher in temperature and pressure). Intermediate temperature and pressure from the outlet of the proportional control valve 22 to the compressor 70. On the other hand, the refrigerant in a path from the heating expansion valve 26 of the gas injection unit 20 to the compressor 70 via the cooling/heating control unit 40, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30 is changed to a low temperature and a low pressure.

The refrigerant in the path shown in fig. 9 does not completely enter the cooling and heating control unit 40 from the condenser 50, but passes through the proportional control valve 22 and then enters the compressor 70, and thus a higher temperature and higher pressure refrigerant is obtained.

The four-way switching valve unit 10 causes the refrigerant to flow from the cooling/heating control unit 40 into the outdoor condenser 110 and to flow out to the liquid separation unit 30. Further, the refrigerant flows into the compressor 70 and flows out to the condenser 50.

The gas injection unit 20 causes the refrigerant to flow from the condenser 50, to flow out to the compressor 70 by the proportional control valve 22, and/or to flow out to the cooling/heating control unit 40 through the heating expansion valve 26.

The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70.

The cooling/heating control unit 40 causes the refrigerant to flow in from the gas injection unit 20 and to flow out to the four-way switching valve unit 10 and the liquid separation unit 30 through the outdoor condenser 110.

In the C type, the four-way switching valve unit 10 is separated from the liquid separation unit 30. The pipe ends of the compressor 70 are configured by two pipe ends through which the refrigerant flows in from the gas injection unit 20 and the refrigerant flows in from the liquid separation unit 30, and one pipe end through which the refrigerant flows out to the four-way switching valve unit 10. Further, the gas injection unit 20 and the cooling/heating control unit 40 of the heating circuit, the dehumidification heating circuit, and the refrigeration circuit of type C are independent.

Fig. 10 is an explanatory diagram of a refrigerant circuit of the heat pump system 100 of the type C at the time of dehumidification heating according to the embodiment of the present invention. In the refrigerant circuit of the dehumidification-air heating circuit of fig. 10, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the expansion valve 23 for dehumidification becomes high-temperature and high-pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher-temperature and higher-pressure). Intermediate temperature and pressure from the outlet of the proportional control valve 22 to the compressor 70. On the other hand, the refrigerant in the path from the dehumidification expansion valve 23 of the gas injection unit 20 to the compressor 70 through the evaporator 60, the cooling/heating control unit 40, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30 is changed to a low temperature and a low pressure.

In the refrigerant circuit at the time of the type C heating by dehumidification, it is different from the refrigerant circuit at the time of heating in that the gas injection unit 20 causes the refrigerant to flow in from the condenser 50 and to flow out to the compressor 70 and/or to flow out to the evaporator 60 by using the proportional control valve 22. Otherwise the same as the refrigerant circuit in heating of type C described above.

Fig. 11 is an explanatory diagram of a refrigerant circuit of the type C heat pump system 100 according to the embodiment of the present invention during cooling. In the refrigerant circuit of the refrigeration circuit of fig. 11, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the outdoor condenser 110, and the cooling/heating control unit 40 has a high temperature and a high pressure. On the other hand, the refrigerant in a path from the cooling/heating control unit 40 to the compressor 70 through the evaporator 60, the gas injection unit 20, the condenser 50, the four-way switching valve unit 10, and the liquid separation unit 30 becomes low-temperature and low-pressure.

The four-way switching valve unit 10 causes the refrigerant to flow in from the condenser 50 and flow out to the liquid separation unit 30 and to flow in from the compressor 70 and flow out to the cooling and heating control unit 40 through the outdoor condenser 110.

Next, a refrigerant circuit of type D will be explained. Fig. 12 is an explanatory diagram of a refrigerant circuit of the heat pump system 100 of the embodiment of the present invention in the heating mode of type D. In the refrigerant circuit of the heating circuit of fig. 12, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the heating expansion valve 26 becomes high in temperature and pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher in temperature and pressure). The medium temperature and pressure is from the outlet of the proportional control valve 22 through the liquid separation unit 30 to the compressor 70. It is preferable that a third check valve 31 be provided in a path to the liquid separation unit 30 and the heating expansion valve 26 of the gas injection unit 20. On the other hand, the refrigerant entering the compressor 70 from the heating expansion valve 26 of the gas injection unit 20 through the check valve 41, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30 becomes low-temperature and low-pressure.

The four-way switching valve unit 10 causes the refrigerant to flow from the gas injection unit 20, through the check valve 41 and the outdoor condenser 110, and to flow out to the liquid separation unit 30. Further, the refrigerant flows into the compressor 70 and flows out to the condenser 50.

The gas injection unit 20 causes the refrigerant to flow from the condenser 50, to flow out to the compressor 70 through the liquid separation unit 30 by the proportional control valve 22, and/or to flow out to the four-way switching valve unit 10 from the heating expansion valve 26 through the check valve 41 and the outdoor condenser 110.

The type D is characterized in that the four-way switching valve unit 10 is further provided with a check valve 41 and a cooling expansion valve 42 without using the cooling/heating control unit 40. When the battery inverter cooler 130 is used, it is preferable to further include a battery expansion valve 43. The pipe ends of the compressor are configured by one pipe end into which the refrigerant flows from the liquid separation unit 30 and one pipe end from which the refrigerant flows out to the four-way switching valve unit 10. The gas injection unit 20 causes the refrigerant to flow into the end of the gas-phase pipe provided in the liquid separation unit 30. In addition, in the D type, the four-way switching valve unit 10 is separated from the liquid separation unit 30. Further, the gas injection units 20 of the heating circuit, the heating and dehumidifying circuit, and the cooling circuit of type D are independent.

Fig. 13 is an explanatory diagram of a refrigerant circuit of the heat pump system 100 of the type D at the time of dehumidification heating according to the embodiment of the present invention. In the refrigerant circuit of the dehumidification-air heating circuit of fig. 13, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the condenser 50, the inlet of the proportional control valve 22 of the gas injection unit 20, and the expansion valve 23 for dehumidification becomes high-temperature and high-pressure (the refrigerant in the path from the compressor 70 to the condenser 50 becomes higher-temperature and higher-pressure). The intermediate temperature and pressure is from the outlet of the proportional control valve 22 through the liquid separation unit 30 to the compressor 70. Further, it is preferable that a third check valve 31 is provided in a path to the liquid separation unit 30 and the dehumidification expansion valve 23 of the gas injection unit 20. On the other hand, the refrigerant in the path from the dehumidification expansion valve 23 of the gas injection unit 20 to the compressor 70 via the check valve 41, the outdoor condenser 110, the four-way switching valve unit 10, and the liquid separation unit 30 is changed to a low temperature and a low pressure.

In the refrigerant circuit at the time of dehumidification-heating of type D, the gas injection unit 20 causes the refrigerant to flow in from the condenser 50 and to flow out to the compressor 70 and/or to the evaporator 60 through the liquid separation unit 30 using the proportional control valve 22. Otherwise the same as the refrigerant circuit in heating of type D described above.

Fig. 14 is an explanatory diagram of a refrigerant circuit of the heat pump system 100 of the type D during cooling according to the embodiment of the present invention. In the refrigerant circuit of the refrigeration circuit of fig. 14, the refrigerant in the path from the compressor 70 to the four-way switching valve unit 10, the outdoor condenser 110, the expansion valve 42 for cooling provided in the four-way switching valve unit 10, and the expansion valve 43 for battery in the case where the battery inverter cooler 130 is further provided, has a high temperature and a high pressure. On the other hand, the refrigerant in a path from the expansion valve 42 for cooling provided in the four-way switching valve unit 10, through the evaporator 60, the gas injection unit 20, the condenser 50, the four-way switching valve unit 10, and the liquid separation unit 30, and into the compressor 70 becomes low-temperature and low-pressure.

The four-way switching valve unit 10 allows the refrigerant to flow in from the condenser 50 and flow out to the liquid separation unit 30, and allows the refrigerant to flow in from the compressor 70 and flow out to the expansion valve 42 for cooling and the evaporator 60 through the outdoor condenser 110.

The gas injection unit 20 causes the refrigerant to flow in from the evaporator 60 and flow out toward the condenser 50. The liquid separation unit 30 causes the refrigerant to flow in from the four-way switching valve unit 10 and flow out to the compressor 70.

The above is a description of the schematic configuration and the refrigerant circuit of the heat pump system 100 according to the embodiment of the present invention. The following describes in detail the configurations of the electronic expansion valve 230 and the check valve, such as the gas injection unit 20, the cooling/heating control unit 40, the four-way switching valve unit 10, the proportional control valve 22, the heating expansion valve 26, the dehumidification expansion valve 23, and the cooling expansion valve 42, which are used in the heat pump system 100 according to the embodiment of the present invention.

Fig. 15 is a perspective view of the gas injection unit 20 of the heat pump system 100 used in one embodiment of the present invention. The gas injection unit 20 is provided with at least a proportional control valve 22 and a plurality of metal plates 25 which can be laminated in a gas-tight manner. The plurality of metal plates 25 that can be laminated while maintaining air-tightness will be described in detail below.

Fig. 16 is a schematic view of a plurality of stacked metal plates 25 provided in the gas injection unit 20, fig. 16 (a) is a plan view of the metal plates 25, fig. 16 (B) is a sectional view a-a of the metal plates 25, and fig. 16 (C) is a sectional view B-B. The proportional control valve 22 provided in the gas injection unit 20 is in contact with the upper sides of the plurality of metal plates 25 via a partition base described below. This is to save space. The dehumidification expansion valve 23, the check valve 24, and the heating expansion valve 26 are also in contact with the upper sides of the plurality of metal plates 25 by a partition base described below in the same manner.

As shown in fig. 16 (C), the plurality of stacked metal plates 25 provided in the gas injection unit 20 include at least an upper plate 251, a first intermediate plate 252, a second intermediate plate 253, and a lower plate 254. Through holes are formed in the upper plate 251, the first intermediate plate 252, the second intermediate plate 253, and the lower plate 254, respectively, and these plates are laminated, whereby the refrigerant passes through the through holes, and a part of the refrigerant circuit is formed. Further, a check valve seat, a copper plate, a check valve top plate (not shown), and a unit for abutting the expansion valve may be provided.

As shown in fig. 16 (a), (B), and (C), a partition base 28 is preferably provided. The partition base 28 is provided above the plurality of metal plates 25 that constitute the gas injection unit 20 and can be laminated in a gas-tight manner. The cooling/heating control unit 40 shown in fig. 22 described later is also the same.

The partition base 28 is formed by stacking two or more metal plates, and as shown in fig. 16 (C), is formed by, for example, four

metal plates

281, 282, 283, and 284, and through holes constituting a refrigerant circuit are formed therein.

The partition base 28 is used as a base of the proportional expansion valve 22, the dehumidification expansion valve 23, and the heating expansion valve 26 provided in the gas injection unit 20, and the cooling expansion valve 42 and the battery expansion valve 43 provided in the gas injection unit 40.

By providing the partition base 28, the refrigerant is expanded by the control valves such as the proportional control valve 22, the expansion valve for dehumidification 23, and the expansion valve for heating 26, and the refrigerant is expanded by throttling, thereby achieving a space where the refrigerant is made compact, enabling the efficiency of the passage resistance to be improved, and preventing the generation of refrigerant noise.

The number and thickness of the metal plates for partitioning the base are not limited, and two or more metal plates may be used. The number and thickness of the sheets may be appropriately changed according to the length and flow rate of the circuit. On the other hand, the partition base may be integrally formed without laminating a plurality of metal plates. At this time, the molding is performed by an extension press or the like.

Fig. 17 is a schematic view of an upper plate 251 constituting a plurality of stacked metal plates 25 provided in the gas ejecting unit 20, where fig. 17 (a) is a plan view of the upper plate 251 and fig. 17 (B) is a side view of the upper plate 251. As shown in fig. 17 (a), a through hole is formed in the upper plate 251. The thickness of the upper plate 251 is preferably 1.0 mm. ltoreq. t.ltoreq.2.0 mm (t is the thickness. the same applies hereinafter), and particularly preferably 1.5 mm.

Fig. 18 is a schematic view of a first intermediate plate 252 constituting a plurality of stacked metal plates 25 provided in the gas injection unit 20, fig. 18 (a) is a plan view of the first intermediate plate 252, and fig. 18 (B) is a side view of the first intermediate plate 252. As shown in fig. 18 (a), the first intermediate plate 252 has a through hole formed therein. In addition, the thickness of the first intermediate plate 252 is preferably 3.0 mm. ltoreq. t.ltoreq.4.0 mm, and particularly preferably 3.5 mm.

Fig. 19 is a schematic view of a second intermediate plate 253 constituting a plurality of stacked metal plates 25 provided in the gas injection unit 20, where fig. 19 (a) is a plan view of the second intermediate plate 253 and fig. 19 (B) is a side view of the second intermediate plate 253. As shown in fig. 19 (a), a through hole is formed in the second intermediate plate 253. In addition, the thickness of the second intermediate plate 253 is preferably 3.0 mm. ltoreq. t.ltoreq.4.0 mm, and particularly preferably 3.5 mm.

Fig. 20 is a schematic view of a lower plate 254 constituting a plurality of stacked metal plates 25 provided in the gas injection unit 20, where fig. 20 (a) is a plan view of the lower plate 254 and fig. 20 (B) is a side view of the lower plate 254. As shown in fig. 20 (a), a through hole is formed in the lower plate 254. The thickness of the lower plate 254 is preferably 1.0 mm. ltoreq. t.ltoreq.2.0 mm, and particularly preferably 1.5 mm.

The through hole provided in the lower plate 254 shown in fig. 20 is connected to the pipe end of the gas injection unit 20, and the pipe ends are connected to the pipe ends of the condenser 50, the evaporator 60, the four-way valve unit 10, the compressor 70, and the cooling/heating control unit 40, respectively, and the refrigerant flows therethrough. Further, the metal plates 25 can be laminated while maintaining airtightness as described above.

Fig. 21 is a perspective view of the cooling/heating control unit 40 used in the heat pump system 100 according to the embodiment of the present invention. The cooling/heating control unit 40 is also provided with at least a plurality of metal plates 45 that can be laminated in a gas-tight manner. A plurality of metal plates 45 that can be laminated while maintaining air-tightness will be described below.

Fig. 22 is a schematic diagram of a plurality of metal plates 45 provided in a stack in the cooling/heating control unit 40, where fig. 22 (a) is a plan view of the metal plates 45, fig. 22 (B) is a C-C sectional view of the metal plates 45, and fig. 22 (C) is a D-D sectional view. When the check valve 41, the expansion valve 42 for cooling, and the expansion valve 43 for battery are provided, they are in contact with the upper sides of the plurality of metal plates 45. This is to save space.

As shown in fig. 22 (C), the plurality of stacked metal plates 45 provided in the cooling/heating control unit 40 include at least an upper plate 451, a first intermediate plate 452, a second intermediate plate 453, and a lower plate 454. Through holes are formed in the upper plate 451, the first intermediate plate 452, the second intermediate plate 453, and the lower plate 454, respectively, and these plates are stacked, so that the refrigerant passes through the through holes to form part of the refrigerant circuit.

The cooling/heating control unit 40 may be provided with a check valve seat 455 and a copper plate 456 against which a check valve abuts. The metal plates 45 can be laminated in an airtight manner as described above.

Next, the four-way switching valve unit 10 will be described. Fig. 23 is a perspective view of the four-way switching valve unit 10 used in the heat pump system 100 according to the embodiment of the present invention, fig. 23 (a) is a perspective view of the four-way switching valve unit 10 when the four-way switching valve unit 10 and the liquid separation unit 30 are combined, fig. 23 (B) is a perspective view of a plurality of stacked metal plates 11 provided at the lower portion of the four-way switching valve unit 10 and viewed from the bottom surface of fig. 23 (a), and fig. 23 (C) is a perspective view of the four-way switching valve unit 10 when the four-way switching valve unit 10 and the liquid separation unit 30 are separated, and a stacked metal plate 11' is further provided at the lower portion of the four-way switching valve unit 10.

The A, B type described above uses the four-way switching valve unit 10 shown in fig. 23 (a). In addition, a plurality of metal plates 11 which can be laminated in an airtight manner as shown in fig. 23 (B) are provided below the unit shown in fig. 23 (a). In the C, D type, a metal plate 11 'further stacked below the stacked metal plates 11 shown in fig. 23 (a) is attached to the four-way switching valve unit 10, and the four-way switching valve unit 10' shown in fig. 23 (C) is used. In the A, B type, the four-way switching valve unit 10 and the liquid separation unit 30 are integrated, and therefore, a metal plate 11' further laminated below the laminated metal plate 11 shown in fig. 23 (B) may not be used.

Next, the structure of the four-way switching valve unit 10 will be described. Fig. 24 is a schematic view of the cylindrical body 12 provided in the four-way switching valve unit 10, fig. 24 (a) is a perspective view of the cylindrical body 12, fig. 24 (B) is a cross-sectional view of a side surface of the cylindrical body 12, and fig. 24 (C) is a cross-sectional view taken along a line a-a of fig. 24 (B).

As shown in fig. 24 (a), (B), and (C), the four-way switching valve unit 10 includes: the refrigerant supply device includes a first connection port 13 through which a refrigerant is supplied, a cylinder 12 through which the refrigerant is supplied from the first connection port 13, a spool 14 provided in the cylinder 12 and movable in an axial direction of the cylinder 12 so as to be connectable in one of two different ways, and three

second connection ports

15, 16, and 17 through which the refrigerant is supplied to and from the spool 14.

The spool 14 is formed in a chevron shape, and a convex portion 18 is provided on the top surface of the spool 14, and a concave portion 19 for receiving the convex portion 18 is provided on the inner surface of the cylinder 12. The two concave portions 19 are preferably provided on the inner surface of the cylindrical body 12 so as to be bilaterally symmetrical. The convex portion 18 may be convex, and a protrusion such as a ball made of resin or metal may be used. The concave portion 19 may be a concave portion that receives a convex shape, and a plate spring that is curved into a concave shape is used. When the cooling, heating, dehumidifying and heating are not used, the refrigerant does not flow through the four-way switching valve unit 10, but in this case, the spool 14 is undesirably moved to a position halfway in the axial direction of the cylinder 12 due to vibration of the vehicle or the like. For example, the refrigerant flows from the second connection port 16 to the second connection port 17 according to the position of the spool 14 shown in fig. 24 (C), but if the convex portion 18 and the concave portion 19, which do not function as the above-described stopper, are not provided, the spool 14 can slightly move to the left side in the drawing due to vibration of the vehicle or the like, and the refrigerant can flow to the three connection ports, i.e., the

second connection ports

15, 16, and 17. When the four-way switching valve unit 10 is moved to an intermediate position, the spool 14 cannot move because no pressure difference is generated between the chambers a and B shown in fig. 24 (C) when the refrigerant is caused to flow. Therefore, the convex portion 18 and the concave portion 19 prevent the above-described aspect.

The spool 14 preferably has a spool head 144 formed of metal into a mountain shape and a base 145 of teflon (registered trademark) that fixes the spool head 144. The entire spool 14 may be molded of resin, but in this case, the resin must be thickened in order to provide rigidity, and the space in the cylinder 12 is limited. Therefore, by providing the spool head 144 formed in a chevron shape from metal, the spool 14 can be made thin, space can be saved in the cylinder 12, and various flow rates and pressures can be accommodated. In addition, in the case where all of the spool 14 is molded of resin, the convex portion 18 is made of resin similarly to the problem of mounting, but in the case of resin, there is a concern about wear resistance due to friction with the concave portion 19. On the other hand, by providing the spool head 144 formed of metal into a mountain shape, the convex portion 18 can be made of metal, and the wear resistance is improved. Note that, if SUS or the like is used as the metal, the spool head 144 may be integrated with the teflon base 145 by press molding.

The first connection port 13 corresponds to the refrigerant path X of the four-way switching valve unit, and the

second connection ports

15, 16, and 17 correspond to the refrigerant path U, V, W of the four-way switching valve unit, respectively.

Fig. 25 is a schematic diagram of the four-way switching valve unit 10, fig. 25 (a) is a view seen from the bottom of fig. 23 (a), and fig. 25 (B) is a cross-sectional view taken along line a-a of fig. 25 (a). As shown in fig. 25 (a), a plurality of metal plates 11 are stacked on the cylindrical body 12 shown in fig. 24 (a), and the cylindrical body 12 can hold the refrigerant in an airtight manner. In the description of fig. 25 (B), a plurality of metal plates 11 are stacked on the upper portion of the cylindrical body 12. The plurality of laminated metal plates 11 are composed of a lower plate 111, an intermediate plate 112, and an upper plate 113, and through

holes

115, 116, and 117 of the metal plates 11 are formed in the lower plate 111, the intermediate plate 112, and the upper plate 113, respectively, so that a refrigerant can flow therethrough. The through

holes

115, 116, and 117 of the metal plate 11 are connected to match the

second connection ports

15, 16, and 17.

The through

holes

115, 116, and 117 formed in the lower plate 111 preferably have a diameter larger than the diameter of the

second connection ports

15, 16, and 17. If provided in this manner, the connectivity is improved and the airtightness can be further maintained.

Next, the structure of the proportional control valve 22 provided in the gas injection unit 20 will be described. Fig. 26 is a sectional view of the proportional control valve 22 provided in the gas injection unit 20.

As shown in fig. 26, the proportional control valve 22 is characterized by having: a body portion 221; a support column 222 provided in the body 221; a magnet 223 and a pulse motor 224 fixed to the support column 222 so that the support column 222 can move in the vertical direction to adjust the flow rate of the refrigerant; a stopper (japanese: スライサー)225 fixed to the body 221; and an upper stopper 226 and a lower stopper 227 for preventing the pillar 222 from excessively moving in the vertical direction, and the pillar 222 is formed with a groove to which the upper stopper 226 and the lower stopper 227 can be attached.

When the magnet is rotated up and down by the pulse motor 224, the column 222 moves up and down. At this time, since the upper stopper 226 and the lower stopper 227 are fixed to the support column, they move up and down simultaneously. The flow rate of the refrigerant is adjusted according to the amount of upward and downward movement thereof. When the flow rate is increased, the number of pulses may be increased so that the support 222 is positioned above.

The stopper 225 is fixed to the body 221. A groove 228 is formed in the support column, an upper stopper 226 is attached to the groove at an upper portion of the support column 222, and a lower stopper 227 is attached to the groove at a lower portion of the support column 222. When the stopper 225, the upper stopper 226, and the lower stopper 227 are attached to each other, the stopper 225 fixed to the body 221 is hooked on the upper stopper 226 and the lower stopper 227 when the support column 222 is to be moved in the vertical direction, and the support column 222 can be moved only in the vertical direction within the distance between the upper stopper 226 and the lower stopper 227. With this arrangement, the pulse motor can be prevented from causing a failure, and the refrigerant can be prevented from excessively flowing out. Further, the upper stopper 226 and the lower stopper 227 may be formed using, for example, C-rings. The electronic expansion valve described below has the same configuration.

The refrigerant flows through the proportional control valve 22 as indicated by arrows a to B. The flow rate of the refrigerant is adjusted by moving a valve seat 222' provided in a support column 222 of the proportional control valve 22 in the axial direction (up and down in fig. 26) of the proportional control valve 22.

In addition, by increasing the length of the valve seat 222' in the axial direction, shaking due to vibration or the like is prevented. Further, the upper portion 229 of the proportional control valve 22 is preferably formed as a curved surface. If the arrangement is such, the internal pressure resistance is improved.

Fig. 27 is a schematic cross-sectional view of the check valve. The heat pump system 100 according to the embodiment of the present invention preferably further includes a vertical check valve 41 as shown in fig. 27. The check valve 41 is characterized in that it has: an outer tub 411; an inner cylinder 412 provided inside the outer cylinder 411; a valve 413 which is provided at the bottom of the inner tube 412 and into which the refrigerant flows and from which the refrigerant does not flow; and a port (hole) 414 provided on a side surface of the inner tube 412 and through which the refrigerant flows out.

The refrigerant flows into the check valve 41 and passes through the check valve as shown by the solid arrows in fig. 27. When the valve 413 is pushed upward in fig. 27 by the refrigerant, a gap is generated between the valve 413 and the inner tube 412, and the refrigerant flows into the inner tube 412 from the gap. The refrigerant flowing in flows out from a port (hole) 414 provided in a side surface of the inner tube 412, and flows out through a gap provided between the outer tube 411 and the inner tube 412. On the other hand, even if the refrigerant flows into the inner tube 413 through the port 414 from the left side in fig. 27, the refrigerant does not flow out to the left side in fig. 27 from the valve 413 because the valve 413 is provided.

The check valve is generally horizontal, but the check valve 41 used in the heat pump system 100 of an embodiment of the present invention is vertical. The structure of the check valve 41 can be applied to the first check valve 24 and the second check valve 27.

Fig. 28 is a sectional view of the expansion valve for heating, the expansion valve for dehumidification, and the expansion valve for cooling. The expansion valve for heating, the expansion valve for dehumidification, and the expansion valve for cooling used in the heat pump system 100 according to the embodiment of the present invention are collectively referred to as an electronic expansion valve 230 described below. As shown in fig. 28, the electronic expansion valve 230 includes: a main body portion 231; a support column 232 provided in the body 231; a magnet 233 and a pulse motor 234 fixed to the support column 232 so that the support column 232 can move in the vertical direction to adjust the flow rate of the refrigerant; a stopper 235 fixed to the body 231; and an upper stopper 236 and a lower stopper 237 for preventing the support column 232 from being excessively moved in the vertical direction, and the support column 232 is formed with a groove 238 to which the upper stopper 236 and the lower stopper 237 can be attached.

When the magnet is rotated up and down by the pulse motor 234, the column 232 moves up and down. At this time, since the upper stopper 236 and the lower stopper 237 are fixed to the support, they move up and down simultaneously. The flow rate of the refrigerant is adjusted according to the amount of upward and downward movement thereof. When the flow rate is increased, the number of pulses may be increased to bring the support 232 closer to the upper side.

The stopper 235 is fixed to the body 231. A groove 238 is formed in the support column, an upper stopper 236 is attached to the groove at an upper portion of the support column 232, and a lower stopper 237 is attached to the groove at a lower portion of the support column 232. By attaching the stopper 235, the upper stopper 236, and the lower stopper 237, when the support column 232 is intended to move in the vertical direction, the stopper 235 fixed to the main body 231 is hooked on the upper stopper 236 and the lower stopper 237, and the support column 232 can move only in the vertical direction within the distance between the upper stopper 236 and the lower stopper 237. With this arrangement, the pulse motor can be prevented from causing a failure, and the refrigerant can be prevented from excessively flowing out.

As described above, according to the present invention, it is possible to provide a heat pump system that is compact, lightweight, and thin, and in which the refrigerant control member is integrally formed in advance and unitized in order to achieve excellent assembly workability, improve productivity, and reduce manufacturing cost, and that can achieve cost performance for compactness, and in particular, can sufficiently cope with extremely low temperatures.

Industrial applicability

The piping unit for an automobile air conditioner according to the present invention is used in a heat pump system mounted in a driving type automobile in which an internal combustion engine is not always started, for example, an Electric Vehicle (EV), a Fuel Cell Vehicle (FCV), or the like.

As described above, the embodiments and examples of the present invention have been described in detail, but it will be readily apparent to those skilled in the art that various modifications can be made without substantially departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention.

For example, in the specification or the drawings, a term described at least once together with a different term having a broader meaning or the same meaning can be replaced with the different term at any position in the specification or the drawings. The structure and operation of the heat pump system are not limited to those described in the embodiments of the present invention, and various modifications can be made.

Description of the reference numerals

10. 10', a four-way switching valve unit; 11. a plurality of metal plates (of the four-way switching valve unit) stacked; 11' and a metal plate (provided below a plurality of metal plates provided in the four-way switching valve unit); 12. a barrel; 13. a first connection port; 14. a spool; 15. 16, 17 and a second connection port; 18. a convex portion; 19. a recess; 20. a gas injection unit; 22. a proportional control valve; 23. an expansion valve for dehumidification; 24. a first check valve; 25. a plurality of metal plates (gas injection units) stacked; 26. an expansion valve for heating; 27. a second check valve; 28. a partition base; 30. a liquid separation unit; 31. a third check valve; 40. a cooling and heating control unit; 41. a check valve; 42. an expansion valve for refrigeration; 43. an expansion valve for the battery; 45. a plurality of metal plates (cooling/heating control means) stacked; 48. a partition base; 50. a condenser; 60. an evaporator; 100. a heat pump system; 110. an outdoor condenser; 120. a blower; 130. a battery inverter cooler; 111. a lower plate; 112. a middle plate; 113. an upper plate; 115. 116, 117 and a through hole of the metal plate; 144. a spool head; 145. a Teflon base; 221. a main body portion; 222. a pillar; 222', a valve seat; 223. a magnet; 224. a pulse motor; 225. a limiting member; 226. an upper stop; 227. a lower stopper; 228. a groove; 229. the upper part of the proportional control valve; 230. an electronic expansion valve; 231 main body part, 232 support, 233 magnet, 234 pulse motor, 235 stopper; 236. an upper stop; 237. a lower stopper; 238. a groove; 251. an upper plate; 252. a first intermediate plate; 253. a second intermediate plate; 254. a lower plate; 281. 282, 283, 284, a metal plate (separating the bases); 411. an outer cylinder; 412. an inner barrel; 413. a valve; 414. a port; 451. an upper plate; 452. a first intermediate plate; 453. a second intermediate plate; 454. a lower plate; 455. a check valve seat; 456. a copper plate; 481. 482, 483, 484, (of a divided base) metal plate; u, V, X, W, a four-way switching valve unit; A. and B, a chamber of the cylinder provided in the four-way switching valve unit.

Claims

1. A heat pump system for an extremely low temperature specification of an air conditioner for an automobile,

the heat pump system includes:

a four-way switching valve unit which, in correspondence with the switching of the cooling, heating and dehumidifying functions, switches the four refrigerant paths in pairs between the two sets of paths;

a gas injection unit provided with a proportional control valve and a plurality of metal plates which can be laminated in a gas-tight manner;

a liquid separation unit that separates liquid;

a cooling/heating control unit that is provided with a plurality of metal plates that can be laminated in an airtight manner and switches the cooling, heating, and dehumidifying functions;

a condenser that condenses the refrigerant or an evaporator that expands the refrigerant; and

a compressor that compresses the refrigerant,

the four-way switching valve unit causes the refrigerant to flow in from the cooling/heating control unit and flow out to the liquid separation unit and causes the refrigerant to flow in from the compressor and flow out to a condenser, or causes the refrigerant to flow in from the condenser and flow out to the liquid separation unit and flow in from the compressor and flow out to the cooling/heating control unit,

the gas injection unit causes the refrigerant to flow in from the condenser and to flow out to the compressor and/or to the cooling and heating control unit or the evaporator using the proportional control valve, or causes the refrigerant to flow in from the evaporator and to flow out to the condenser,

the liquid separation unit causes the refrigerant to flow in from the four-way switching valve unit and flow out to the compressor,

the cooling/heating control unit causes the refrigerant to flow in from the gas injection unit and flow out to the four-way switching valve unit, or to flow in from the four-way switching valve unit and flow out to the gas injection unit.

2. The heat pump system of claim 1,

the four-way switching valve unit and the liquid separation unit are combined,

the piping ends of the compressor are composed of two piping ends that flow in from the gas injection unit and flow in from the liquid separation unit through the proportional control valve and one piping end that flows out to the four-way switching valve unit,

the gas injection unit causes the refrigerant to flow in from the condenser and to flow out to the compressor and to flow out to the cooling and heating control unit or the evaporator using the proportional control valve.

3. The heat pump system of claim 1,

the four-way switching valve unit and the liquid separation unit are combined,

the piping end of the compressor is configured by one piping end into which the refrigerant flows from the liquid separation unit and one piping end from which the refrigerant flows out to the four-way switching valve unit,

the gas injection unit causes the refrigerant to flow into a terminal end of a gas-phase pipe provided in the liquid separation unit,

the liquid separation unit enables the refrigerant to flow out of the cooling and heating control unit or the evaporator through the gas injection unit.

4. The heat pump system of claim 1,

the four-way switching valve unit is separated from the liquid separation unit,

the piping ends of the compressor are configured by two piping ends through which the refrigerant flows in from the gas injection unit and the refrigerant flows in from the liquid separation unit, and one piping end through which the refrigerant flows out to the four-way switching valve unit.

5. The heat pump system of claim 1,

the heat pump system is characterized in that the four-way switching valve unit is further provided with a check valve and a refrigerating expansion valve under the condition that the cooling and heating control unit is not used,

the four-way switching valve unit is separated from the liquid separation unit,

the gas injection unit causes the refrigerant to flow into a terminal end of a gas-phase pipe provided in the liquid separation unit.

6. The heat pump system according to any one of claims 1 to 5,

the four-way switching valve unit includes:

a first connection port through which the refrigerant flows in and out;

a cylinder to which the refrigerant is supplied from the connection port;

a spool formed in a chevron shape, provided in the cylinder, and movable in an axial direction of the cylinder so as to be connectable in one of two modes;

a second connection port through which the refrigerant flows in and out through the spool;

a convex part is arranged on the top surface of the slide valve core,

and the inner surface of the cylinder is provided with a concave part for receiving the convex part.

7. The heat pump system of claim 6,

the spool has: a spool head formed of metal in a chevron shape; and a Teflon base which fixes the spool head.

8. The heat pump system of claim 6,

a plurality of metal plates stacked on each other are provided on the second connection port,

the metal plate is composed of a lower plate, an intermediate plate and an upper plate, through holes are arranged in the metal plate to enable the refrigerant to flow through the through holes,

the through holes of the lower plate, the middle plate and the upper plate have a diameter larger than that of the second connection port.

9. The heat pump system of claim 1,

a partition base formed by stacking two or more metal plates or an integrally formed partition base is provided above the plurality of metal plates that can be stacked while maintaining airtightness, which constitute the gas injection unit and the cooling/heating control unit.

10. The heat pump system of claim 1,

the heat pump system is further provided with a vertical check valve,

the check valve has:

an outer cylinder;

an inner cylinder provided inside the outer cylinder;

a valve provided at the bottom of the inner cylinder and allowing a refrigerant to flow in and not allowing the refrigerant to flow out,

and a port provided on a side surface of the inner tube and through which the refrigerant flows out.

11. The heat pump system of claim 1,

the heat pump system further comprises at least one of a heating expansion valve, a dehumidifying expansion valve, and a cooling expansion valve,

the expansion valve for heating, the expansion valve for dehumidification and the expansion valve for refrigeration have:

a main body portion;

a pillar provided in the main body;

a magnet and a pulse motor fixed to the column so that the column can move in an up-down direction to adjust a flow rate of the refrigerant;

a stopper fixed to the main body; and

an upper stopper and a lower stopper which prevent the strut from being excessively moved in an up-down direction,

the pillar is formed with a groove to which the upper stopper and the lower stopper can be attached.