WO2014054229A1

WO2014054229A1 - Heat pump cycle and integration valve for heat pump cycle

Info

Publication number: WO2014054229A1
Application number: PCT/JP2013/005450
Authority: WO
Inventors: 伊藤　哲也
Original assignee: 株式会社デンソー
Priority date: 2012-10-01
Filing date: 2013-09-13
Publication date: 2014-04-10
Also published as: JP2014070867A

Abstract

A heat pump cycle equipped with: an operating mode switching unit (100a) that switches between a series operating mode, wherein refrigerant flowing from a heat radiator (12) flows through an outdoor heat exchanger (15) and then flows through an evaporator (20), and a parallel operating mode, wherein the refrigerant flowing from the heat radiator flows to both the outdoor heat exchanger and the evaporator; a pressure adjustment unit (44) that adjusts the pressure of the refrigerant passing through the evaporator; and an operating state switching unit (100b) that switches the operating state of the pressure adjustment unit between a function implementation state, wherein a constant pressure adjustment function is implemented to maintain the pressure of the refrigerant passing through the evaporator at a prescribed pressure setting, and a function suspension state, wherein the constant pressure adjustment function is not implemented. The operating state switching unit switches the operating state of the pressure adjustment unit to the function implementation state during the parallel operation mode, and switches the operating state of the pressure adjustment unit to the function suspension state during the series operation mode.

Description

Heat pump cycle and integrated valve for heat pump cycle

Cross-reference of related applications

This disclosure is based on Japanese Patent Application No. 2012-219722 filed on October 1, 2012, the contents of which are incorporated herein.

This disclosure relates to a heat pump cycle and an integrated valve applied to the heat pump cycle.

Conventionally, when dehumidifying and heating an air-conditioned space such as a room, the air blown into the room is cooled and dehumidified by the evaporator of the heat pump cycle, and the low-temperature air dehumidified by the evaporator is radiated from the heat pump cycle. There is known an air conditioner that is reheated by a condenser (condenser) and blown out to an air-conditioning target space (for example, see Patent Documents 1 and 2).

In the air conditioner described in Patent Literature 1, by switching the refrigerant flow path of the heat pump cycle, a heating / dehumidifying operation for dehumidifying the blown air during heating and a weak cooling / dehumidifying operation for dehumidifying the blown air during cooling can be performed.

Specifically, during the heating and dehumidifying operation, the outdoor heat exchanger absorbs heat by switching to the refrigerant flow path connecting in parallel the evaporator and the outdoor heat exchanger that exchanges heat with the outside air on the downstream side of the radiator. It functions as a vessel. In this case, heat is absorbed from the blown air by the evaporator and heat is absorbed from the outdoor air by the outdoor heat exchanger, so that a heat radiation amount of the refrigerant in the radiator can be secured and high-temperature blown air can be blown out into the room.

On the other hand, during the weak cooling and dehumidifying operation, the outdoor heat exchanger is caused to function as a radiator by switching to the refrigerant flow path connecting the radiator and the outdoor heat exchanger in parallel on the downstream side of the compressor. In this case, heat is radiated to the blown air by the radiator, and heat is radiated to the outside air by the outdoor heat exchanger, so that the amount of heat absorbed by the refrigerant in the evaporator can be secured, and the low-temperature blown air can be blown into the room.

Further, in the air conditioner described in Patent Document 2, a refrigerant flow path similar to that in Patent Document 1 is used during heating and dehumidifying operation, and a radiator, an outdoor heat exchanger, and an evaporator are disposed downstream of the compressor during weak cooling and dehumidifying operation. Are switched to the refrigerant flow path connected in series, and the outdoor heat exchanger functions as a radiator. Also in this case, it is possible to secure the heat absorption amount of the refrigerant in the evaporator by dissipating the refrigerant in both the radiator and the outdoor heat exchanger.

Japanese Patent No. 3645324 Japanese Patent Application Laid-Open No. 06-341732

By the way, as in the heating and dehumidifying operation of Patent Documents 1 and 2, the refrigerant flow path connecting the evaporator and the outdoor heat exchanger in parallel, and when the outdoor heat exchanger functions as a heat absorber, Even if the endothermic amount of the refrigerant in the evaporator is changed in order to change the temperature, the endothermic amount from the outside air in the outdoor heat exchanger cannot be adjusted appropriately. As a result, the temperature adjustment range of the blown air into the room is limited.

The reason is that in the refrigerant flow path in which the evaporator and the outdoor heat exchanger are connected in parallel as in Patent Documents 1 and 2, the refrigerant evaporation temperature in the indoor evaporator matches the refrigerant evaporation temperature in the outdoor heat exchanger. Because.

For example, in order to increase the temperature of the air blown into the room, the refrigerant evaporation temperature in the outdoor heat exchanger may be decreased and the heat absorption amount of the refrigerant in the outdoor heat exchanger may be increased. However, if the refrigerant evaporation temperature in the outdoor heat exchanger is lowered, the refrigerant evaporation temperature of the evaporator is also lowered, so that frost (frost) is generated in the evaporator.

On the other hand, in order to lower the temperature of the air blown into the room, the refrigerant evaporation temperature in the outdoor heat exchanger may be increased and the heat absorption amount of the refrigerant in the outdoor heat exchanger may be reduced. However, if the refrigerant evaporation temperature in the outdoor heat exchanger is raised, the refrigerant evaporation temperature of the evaporator also rises, so that the blown air cannot be sufficiently dehumidified.

On the other hand, the inventors of the present invention, in the prior Japanese Patent Application No. 2011-82761 (hereinafter referred to as the prior application example), the serial operation in which the refrigerant flowing out from the radiator is flowed in the order of the outdoor heat exchanger and the evaporator. The refrigeration cycle apparatus which switches the mode and the parallel operation mode which flows the refrigerant | coolant which flowed out from the heat radiator to both an outdoor heat exchanger and an evaporator is proposed.

Furthermore, in the prior application example, a constant pressure adjusting unit that maintains the pressure of the refrigerant on the evaporator outlet side at a predetermined pressure is disposed, and the pressure of the refrigerant on the outdoor heat exchanger outlet side and the evaporator outlet side in the parallel operation mode are arranged. By making it possible to adjust the pressure of the refrigerant to different pressures, the heat absorption amounts of the outdoor heat exchanger and the evaporator can be appropriately adjusted.

Here, in the prior application example, a constant pressure valve composed of a bellows or the like is adopted as the constant pressure adjusting unit, but the control pressure in the constant pressure valve of the prior application example is proportional to the increase in the refrigerant flow rate on the evaporator outlet side. Tend to rise.

For this reason, when a constant pressure valve that maintains the pressure of the refrigerant at the outlet side of the evaporator at a predetermined set pressure value is arranged as in the prior application example, as shown in FIG. 17, during the cooling operation (series operation mode), When the refrigerant flow rate is high and the target evaporator temperature is low (conditions where cooling capacity is required), the refrigerant pressure on the outlet side of the evaporator rises more than necessary, and it is necessary to secure the target cooling capacity. It will become higher than the pressure (target refrigerant pressure).

That is, in the prior application example, in order to increase the cooling capacity in the serial operation mode, even if the rotation speed of the compressor is increased, the refrigerant pressure on the evaporator outlet side does not decrease to an appropriate pressure. The capacity cannot be increased appropriately, and only the power of the compressor is increased (this is referred to as control interference between the constant pressure valve and the compressor).

In view of the above points, the present disclosure provides a heat pump cycle capable of appropriately changing the heat absorption amounts of the evaporator and the outdoor heat exchanger in the parallel operation mode and appropriately adjusting the cooling capacity in the series operation mode. This is the first purpose.

Also, a second object is to provide a heat pump cycle integrated valve that can simplify the cycle configuration of the heat pump cycle that can achieve the first object.

In order to achieve the first object, a heat pump cycle according to an embodiment of the present disclosure radiates heat to a compressor that compresses and discharges a refrigerant, and blown air that blows the refrigerant discharged from the compressor to an air-conditioning target space. Heat exchanger, outdoor heat exchanger that exchanges heat from the refrigerant that flows out of the radiator with the outside air, evaporator that evaporates the refrigerant flowing in the cycle and cools the blown air before passing through the radiator, and outflow from the radiator An operation mode switching unit that switches between a serial operation mode in which the refrigerant flows in the order of the outdoor heat exchanger and the evaporator, and a parallel operation mode in which the refrigerant that has flowed out of the radiator flows to both the outdoor heat exchanger and the evaporator, and an evaporator A pressure adjusting unit that adjusts the pressure of the circulating refrigerant, and a function exhibiting state that exhibits a constant pressure adjusting function that maintains the pressure of the refrigerant flowing through the evaporator at a predetermined set pressure value. Provided and the operating state switching portion for switching to the function stop state not exhibiting said pressure adjusting function, a. The operation state switching unit switches the operation state of the pressure adjustment unit to the function exhibiting state during the parallel operation mode, and switches the operation state of the pressure adjustment unit to the function stop state during the series operation mode.

According to this, since the pressure of the refrigerant at the outlet side of the evaporator is maintained at the set pressure value in the parallel operation mode, the heat absorption amount of the refrigerant in the evaporator and the outdoor heat exchanger Each endothermic amount of the refrigerant can be appropriately changed.

Further, in the series operation mode, the pressure adjustment unit does not maintain the pressure of the refrigerant on the evaporator outlet side at the set pressure value, so that the control interference between the constant pressure valve and the compressor does not occur, and the evaporator outlet side It is possible to adjust the pressure of the refrigerant to a pressure required to secure the target cooling capacity.

Therefore, according to the heat pump cycle of the present disclosure, the heat absorption amounts of the evaporator and the outdoor heat exchanger in the parallel operation mode can be appropriately changed, and the cooling capacity in the series operation mode can be appropriately adjusted.

An integrated valve for a heat pump cycle according to an embodiment of the present disclosure includes a radiator that dissipates heat discharged from a compressor to blown air that blows air to a space to be air-conditioned, and outdoor heat that exchanges heat between the refrigerant flowing out of the radiator and the outside air. An exchanger, an evaporator that evaporates the refrigerant flowing in the cycle and cools the blown air before passing through the radiator, a series operation mode in which the refrigerant flowing out of the radiator flows in the order of the outdoor heat exchanger, the evaporator, and heat dissipation The present invention is applied to a heat pump cycle that can be switched to a parallel operation mode in which the refrigerant flowing out of the vessel flows to both the outdoor heat exchanger and the evaporator.

In order to achieve the second object, the integrated valve for the heat pump cycle includes a first refrigerant passage that guides the refrigerant flowing out of the outdoor heat exchanger to the evaporator side in the series operation mode, and the refrigerant flowing out of the radiator in the parallel operation mode. Bypass body that bypasses the outdoor heat exchanger and leads to the evaporator side, a body in which a second refrigerant passage that guides the refrigerant that has flowed out of the evaporator to the suction side of the compressor is formed, and the bypass passage that is housed inside the body By driving the bypass opening / closing valve body for opening and closing the first actuating rod connected to the bypass opening / closing valve body, the bypass opening / closing valve body is displaced to the closed position of the bypass passage in the series operation mode, A drive unit for displacing the bypass opening / closing valve element to the open position of the bypass passage in the parallel operation mode, and a preset pressure that sets the pressure of the refrigerant accommodated in the body and flowing into the second refrigerant passage A pressure adjusting valve body for maintaining the value and the second refrigerant passage when the drive unit displaces the bypass opening / closing valve body to the closed position of the bypass passage than when the drive portion is displaced to the open position of the bypass passage. And a second actuating rod that displaces the pressure adjusting valve element so that the passage opening degree of the second pressure adjusting valve increases.

According to this, when the bypass opening / closing valve element is displaced to the open position of the bypass passage in the parallel operation mode, the pressure of the refrigerant on the evaporator outlet side is maintained at the set pressure value by the pressure adjusting valve element. Since it becomes a structure, in the parallel operation mode, each of the heat absorption amount of the refrigerant in the evaporator and the heat absorption amount of the refrigerant in the outdoor heat exchanger can be appropriately changed.

Further, when the bypass opening / closing valve body is displaced to the closed position of the bypass passage in the series operation mode, the passage opening degree of the second refrigerant passage is enlarged by the pressure adjusting valve body, and the refrigerant on the evaporator outlet side is expanded. Therefore, the refrigerant pressure at the outlet side of the evaporator is required to secure the target cooling capacity without causing control interference between the pressure adjusting valve body and the compressor. The pressure can be adjusted.

Therefore, according to the integrated valve for the heat pump cycle of the present disclosure, it is possible to appropriately change the heat absorption amounts of the evaporator and the outdoor heat exchanger in the parallel operation mode and appropriately adjust the cooling capacity in the series operation mode.

Further, at least a bypass opening / closing valve body and a pressure adjusting valve body are accommodated and integrated in the body in which the first and second refrigerant passages and the bypass passage are formed, and the pressure adjusting valve body is further displaced. The pressure adjusting valve body is displaced by the second operating rod in conjunction with the displacement of the bypass passage to the closed position without providing a dedicated displacement portion (driving portion) for the heat pump cycle. The cycle configuration can be simplified.

The second operating rod is connected to at least one of the bypass opening / closing valve body and the pressure adjusting valve body, and the pressure adjusting valve body is displaced in conjunction with the displacement of the bypass opening / closing valve body. To do.

In this way, if the pressure adjusting valve element is displaced in conjunction with the bypass opening / closing valve element, the displacement of the pressure adjusting valve element is adjusted by the drive unit, so that the evaporator outlet side Since the refrigerant pressure can be maintained at the set pressure value, the cycle configuration of the heat pump cycle can be realized with a simpler configuration.

Further, the bypass passage is joined to the first refrigerant passage on the downstream side of the refrigerant flow with respect to the bypass opening and closing valve body, and the drive unit places the bypass opening and closing valve body in the opening position of the bypass passage in the first refrigerant passage. A backflow prevention valve is arranged to prevent the refrigerant flowing through the bypass passage from flowing out to the outdoor heat exchanger side through the first refrigerant passage.

According to this, since the bypass opening / closing valve body, the pressure adjusting valve body, and the backflow prevention valve are housed and integrated in the body, the cycle configuration of the heat pump cycle can be realized with a simpler configuration.

It is a schematic block diagram of the vehicle air conditioner which concerns on 1st Embodiment. It is sectional drawing of the function display state which exhibits the constant pressure adjustment function of the integrated valve which concerns on 1st Embodiment. It is sectional drawing of the function stop state which does not exhibit the constant pressure adjustment function of the integrated valve which concerns on 1st Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of the air_conditioning | cooling mode in the heat pump cycle which concerns on 1st Embodiment. It is explanatory drawing for demonstrating the effect | action of the heat exchange between the refrigerant | coolants in the integrated valve at the time of air_conditioning | cooling mode. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of the 1st dehumidification heating mode (2nd mode) in the heat pump cycle which concerns on 1st Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of the 1st dehumidification heating mode (3rd mode) in the heat pump cycle which concerns on 1st Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of the 1st dehumidification heating mode (4th mode) in the heat pump cycle which concerns on 1st Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant at the time of the 2nd dehumidification heating mode in the heat pump cycle which concerns on 1st Embodiment. It is explanatory drawing for demonstrating the effect | action of the heat exchange between the refrigerant | coolants in the integrated valve at the time of 2nd dehumidification heating mode. It is sectional drawing which shows the modification of the integrated valve which concerns on 1st Embodiment. It is sectional drawing of the function display state which exhibits the constant pressure adjustment function of the integrated valve which concerns on 2nd Embodiment. It is sectional drawing of the function stop state which does not exhibit the constant pressure adjustment function of the integrated valve which concerns on 2nd Embodiment. It is sectional drawing which shows the modification of the integrated valve which concerns on 2nd Embodiment. It is sectional drawing which shows the modification of the integrated valve which concerns on 2nd Embodiment. It is sectional drawing of the integrated valve which concerns on 3rd Embodiment. It is explanatory drawing for demonstrating the control interference of a constant pressure valve and a compressor.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
First, the first embodiment will be described. In the present embodiment, a heat pump cycle 10 and a heat pump cycle integrated valve (hereinafter abbreviated as an integrated valve 4) 4 of a hybrid vehicle that obtains driving force for vehicle travel from an internal combustion engine (engine) and a travel electric motor. This is applied to the vehicle air conditioner 1. The heat pump cycle 10 functions in the vehicle air conditioner 1 to cool or heat the vehicle interior air blown into the vehicle interior that is the air-conditioning target space.

For this reason, the heat pump cycle 10 includes a cooling mode (cooling operation) refrigerant flow path for cooling the vehicle interior, a dehumidification heating mode (dehumidification operation) refrigerant flow path for heating while dehumidifying the vehicle interior, and heating for heating the vehicle interior. The refrigerant flow path in the mode (heating operation) can be switched.

Further, in the heat pump cycle 10, as described later, as the dehumidifying heating mode, a first dehumidifying heating mode that is executed during normal time and a second dehumidifying heating mode that is executed when the outside air temperature is extremely low can be executed. it can.

In the present embodiment, among the various operation modes, the cooling mode and the first dehumidifying and heating mode correspond to a series operation mode in which the refrigerant flowing out of the indoor condenser 12 is flowed in the order of the outdoor heat exchanger 15 and the indoor evaporator 20. The second dehumidifying and heating mode corresponds to a parallel operation mode in which the refrigerant that has flowed out of the indoor condenser 12 flows to both the outdoor heat exchanger 15 and the indoor evaporator 20.

Further, in the heat pump cycle 10 of the present embodiment, a normal chlorofluorocarbon refrigerant is employed as the refrigerant, and a subcritical refrigeration cycle in which the pressure of the high-pressure refrigerant does not exceed the critical pressure of the refrigerant is configured.

The compressor 11 sucks the refrigerant in the heat pump cycle 10, compresses and discharges it, and is an electric compressor that drives the compression mechanism 11b by the electric motor 11a. Specifically, various compression mechanisms such as a scroll-type compression mechanism and a vane-type compression mechanism can be employed as the compression mechanism 11b.

The electric motor 11a is controlled in its operation (number of rotations) by a control signal output from the control device 100 described later, and may adopt either an AC motor or a DC motor. And the refrigerant | coolant discharge capability of the compression mechanism 11b is changed by this rotation speed control. Therefore, in this embodiment, the electric motor 11a comprises the discharge capability change part of the compression mechanism 11b.

The inlet side of the indoor condenser 12 is connected to the discharge port side of the compressor 11. The indoor condenser 12 is disposed in a casing 31 of an indoor air conditioning unit 30 described later, dissipates refrigerant discharged from the compressor 11 (high-pressure refrigerant), and passes through the indoor evaporator 20 described later. It is a radiator that heats the air.

A high-pressure passage 13 that guides the refrigerant flowing out of the indoor condenser 12 to an outdoor heat exchanger 15 described later is connected to the outlet side of the indoor condenser 12. The high pressure side passage 13 is provided with a first expansion valve (first throttling portion) 14 configured to change the passage area (throttle opening) of the high pressure side passage 13.

More specifically, the first expansion valve 14 includes a valve body configured to change the passage opening (throttle opening) of the high-pressure side passage 13, and a stepping motor that changes the throttle opening of the valve body. And an electric variable aperture mechanism configured to include the electric actuator.

The first expansion valve 14 of the present embodiment is composed of a variable throttle mechanism with a fully open function that fully opens the high-pressure side passage 13 when the throttle opening is fully opened. That is, the first expansion valve 14 can prevent the refrigerant from depressurizing by fully opening the high-pressure side passage 13. The operation of the first expansion valve 14 is controlled by a control signal output from the control device 100.

The inlet side of the outdoor heat exchanger 15 is connected to the outlet side of the first expansion valve 14. The outdoor heat exchanger 15 exchanges heat between the refrigerant circulating inside and the outside air blown from a blower fan (not shown). The outdoor heat exchanger 15 functions as an evaporator that evaporates the refrigerant and exerts an endothermic effect in a heating mode, which will be described later, and functions as a radiator that radiates the refrigerant in a cooling mode.

On the outlet side of the outdoor heat exchanger 15, the first low-pressure side passage 16 that guides the refrigerant flowing out of the outdoor heat exchanger 15 to the suction side of the compressor 11 through an accumulator 22 described later, and the outdoor heat exchanger 15. A second low-pressure side passage 18 is connected to guide the discharged refrigerant to the suction side of the compressor 11 via an indoor evaporator 20 and an accumulator 22 which will be described later.

The first low-pressure side passage 16 is provided with a first on-off valve (first on-off portion) 17. The low-pressure side opening / closing valve 17 is an electromagnetic valve that opens and closes the first low-pressure side passage 16, and its operation is controlled by a control signal output from the control device 100.

When the first low-pressure side passage 16 is opened by the low-pressure side opening / closing valve 17, the control device 100 of the present embodiment closes the second low-pressure side passage 18 by the second expansion valve 19 described later. The low pressure side opening / closing valve 17 and the second expansion valve 19 are controlled. Conversely, when the first low-pressure side passage 16 is closed by the low-pressure side opening / closing valve 17, the low-pressure side opening / closing valve 17 and the second low-pressure side opening / closing valve 17 are opened so that the second low-pressure side passage 18 is opened by the second expansion valve 19 described later. The expansion valve 19 is controlled. Accordingly, the refrigerant flowing out of the outdoor heat exchanger 15 flows to the first low pressure side passage 16 side when the low pressure side opening / closing valve 17 is open, and when the low pressure side opening / closing valve 17 is closed, 2 Flows to the low pressure side passage 18 side.

Thus, the low-pressure side opening / closing valve 17 functions to switch the cycle configuration (refrigerant flow path) by opening and closing the first low-pressure side passage 16. Therefore, the low-pressure side opening / closing valve 17 constitutes a refrigerant flow switching unit that switches the refrigerant flow of the refrigerant circulating in the cycle.

The second low pressure side passage 18 is provided with a second expansion valve (second throttle portion) 19 configured so that the passage area (throttle opening) of the second low pressure side passage 18 can be changed. More specifically, the second expansion valve 19 changes the opening degree of the second low-pressure side passage 18 (throttle opening degree) and the throttle opening degree of the valve body. This is an electric variable aperture mechanism that includes an electric actuator including a stepping motor.

The second expansion valve 19 of the present embodiment fully opens the second low pressure side passage 18 when the throttle opening is fully opened, and closes the second low pressure side passage 18 when the throttle opening is fully closed. It consists of a variable throttle mechanism with a fully closed function. That is, the second expansion valve 19 can prevent the refrigerant from depressurizing and can open and close the second low-pressure side passage 18. The operation of the second expansion valve 19 is controlled by a control signal output from the control device 100.

The inlet side of the indoor evaporator 20 is connected to the outlet side of the second expansion valve 19. The indoor evaporator 20 is disposed in the casing 31 of the indoor air-conditioning unit 30 on the upstream side of the air flow in the vehicle interior of the indoor condenser 12, and the refrigerant that circulates in the interior thereof in the cooling mode, the dehumidifying heating mode, and the like. The evaporator cools the air blown into the vehicle interior by exchanging heat with the air blown into the vehicle compartment before passing through the indoor condenser 12 (before passing through the radiator) and evaporating it.

The inlet side of the accumulator 22 is connected to the outlet side of the indoor evaporator 20 via the evaporator outlet side passage 21. The accumulator 22 is a gas-liquid separator that separates the gas-liquid refrigerant flowing into the accumulator 22 and stores excess refrigerant in the cycle. The suction port side of the compressor 11 is connected to the gas phase refrigerant outlet of the accumulator 22. Therefore, the accumulator 22 functions to prevent the liquid phase refrigerant from being sucked into the compressor 11 and prevent liquid compression in the compressor 11.

In the present embodiment, the refrigerant in the range from the outlet side of the indoor condenser 12 in the high-pressure side passage 13 to the inlet side of the first expansion valve 14 is supplied to the outlet side of the outdoor heat exchanger 15 in the second low-pressure side passage 18. A bypass passage 41 that leads to a range from the first expansion valve 19 to the inlet side of the second expansion valve 19 is provided. In other words, the bypass passage 41 is a refrigerant passage that guides the refrigerant flowing out of the indoor condenser 12 to the inlet side of the second expansion valve 19 by bypassing the first expansion valve 14 and the outdoor heat exchanger 15.

In the bypass passage 41, a bypass opening / closing valve 42 is arranged. The bypass opening / closing valve 42 is an electromagnetic valve that opens and closes the bypass passage 41, and its operation is controlled by a control signal output from the control device 100.

The bypass opening / closing valve 42 functions to switch the cycle configuration (refrigerant flow path) by opening and closing the bypass passage 41. Therefore, the bypass opening / closing valve 42 constitutes a refrigerant flow path switching unit that switches the refrigerant flow path of the refrigerant circulating in the cycle together with the low pressure side opening / closing valve 17.

In the present embodiment, a check valve (backflow prevention valve) 43 is provided between the outlet side of the outdoor heat exchanger 15 in the second low-pressure side passage 18 and the junction of the bypass passage 41 and the second low-pressure side passage 18. Is arranged. The check valve 43 allows the refrigerant to flow from the outlet side of the outdoor heat exchanger 15 to the inlet side of the second expansion valve 19, and from the inlet side of the second expansion valve 19 to the outlet side of the outdoor heat exchanger 15. The check valve 43 prevents the refrigerant that has joined the second low-pressure side passage 18 from flowing to the outdoor heat exchanger 15 side.

Further, in the present embodiment, the pressure regulating valve 44 is disposed in the evaporator outlet side passage 21 between the outlet side of the indoor evaporator 20 and the joining portion of the accumulator 22 and the first low pressure side passage 16.

The pressure adjusting valve 44 is a pressure adjusting unit that adjusts the pressure of the refrigerant flowing through the indoor evaporator 20. The pressure adjustment valve 44 of the present embodiment is in a function exhibiting state that exhibits a constant pressure adjustment function that maintains the pressure of the refrigerant flowing through the indoor evaporator 20 at a predetermined set pressure value, and a function stop state that does not exhibit the constant pressure adjustment function. It is configured to be switchable.

Here, in this embodiment, in order to simplify the cycle configuration of the heat pump cycle 10, the bypass on-off valve 42, the check valve 43, the pressure adjustment valve 44, and the like surrounded by the one-dot chain line in FIG. Are integrated as one.

Details of the integrated valve 4 will be described with reference to FIGS. 2 and 3 are schematic cross-sectional views of the integrated valve 4 of the present embodiment.

The integrated valve 4 has a body 40 that forms its outer shell and is composed of a columnar metal block body. The body 40 is formed with a first refrigerant passage 18a constituting the second low-pressure side passage 18, a bypass passage 41, and a second refrigerant passage 21a constituting the second low-pressure side passage. In the body 40 of the present embodiment, a bypass passage 41, a first refrigerant passage 18a, and a second refrigerant passage 21a are formed in order from the upper side.

In the parallel operation mode, the bypass passage 41 introduces the refrigerant that has flowed out from the indoor condenser 12 through the first refrigerant introduction port 401 that opens in the side wall of the body 40, and introduces the refrigerant to the lower side of the first refrigerant introduction port 401. This is a refrigerant passage that leads to the indoor evaporator 20 side (second expansion valve 19 side) through the opened first refrigerant outlet port 404.

The bypass passage 41 of the present embodiment includes a pair of passages extending in the radial direction (left and right direction on the paper surface) of the body 40 and a passage extending in the axial direction (up and down direction on the paper surface) of the body 40 and communicating the pair of passages. The refrigerant flowing through the inside flows in a U-shape inside the body 40.

Further, inside the bypass passage 41, a disk-shaped bypass opening / closing valve body 421 for opening and closing the bypass passage 41, a first shaft (first operating rod) connected to the upper surface side of the bypass opening / closing valve body 421 422, a part of a second shaft (second operating rod) 443 connected to a pressure adjusting valve body 441 described later is disposed.

The bypass opening / closing valve element 421 is connected to the movable member of the drive motor 423 via the first shaft 422. The drive motor 423 constitutes a drive unit that displaces the bypass opening / closing valve element 421 to the closed position and the open position of the bypass passage 41 by driving the first shaft 422 in the axial direction.

Specifically, when closing the bypass passage 41, the drive motor 423 displaces the bypass opening / closing valve element 421 to a position in close contact with the valve seat portion 406 formed in the passage extending in the axial direction in the bypass passage 41. When the bypass passage 41 is opened (see FIG. 2), the bypass opening / closing valve element 421 is displaced to a position away from the valve seat 406 (see FIG. 3).

The drive motor 423 of the present embodiment is an electric motor that can arbitrarily displace the bypass opening / closing valve element 421 in the range of the closed position and the open position of the bypass passage 41, such as a stepping motor. Thereby, the opening / closing speed of the bypass passage 41 by the bypass opening / closing valve body 421 can be made moderate. The operation of the drive motor 423 is controlled by a control signal output from the control device 100.

In the bypass opening / closing valve body 421 of the present embodiment, an annular seal member 421a is disposed at a portion that contacts the valve seat portion 406, and the seal when the seal member 421a is in close contact with the valve seat portion 406 is sealed. Is secured. A recess for supporting one end side (upper end side) of a second shaft 443, which will be described later, is formed in the central portion on the lower surface side of the bypass opening / closing valve body 421.

Subsequently, the first refrigerant passage 18a introduces the refrigerant that has flowed out of the outdoor heat exchanger 15 through the second refrigerant introduction port 402 that opens in the side wall of the body 40 in the serial operation mode, and the introduced refrigerant is introduced into the first refrigerant passage. This is a refrigerant passage that leads to the indoor evaporator 20 side (second expansion valve 19 side) via the outlet 404.

The first refrigerant passage 18a of the present embodiment is configured by a passage extending in the radial direction of the body 40 (left and right direction in the drawing), and on the downstream side of the bypass opening / closing valve body 421 in the bypass passage 41, the bypass passage 41 and Have joined.

A check valve 43 is arranged on the second refrigerant introduction port 402 side in the first refrigerant passage 18a. In the check valve 43, when the drive motor 423 displaces the bypass opening / closing valve element 421 to the open position of the bypass passage 41, the refrigerant flowing through the bypass passage 41 exchanges outdoor heat through the first refrigerant passage 18a. It is a backflow prevention valve which prevents flowing out to the container 15 side.

Specifically, as shown in FIG. 2, the check valve 43 is configured such that when the refrigerant flowing through the bypass passage 41 flows toward the second refrigerant introduction port 402, the valve body 431 is moved to the second refrigerant introduction port by the pressure of the refrigerant. The first refrigerant passage 18a is closed when the valve body 431 is brought into close contact with the valve seat portion 432 by being pressed toward the 402 side.

As shown in FIG. 3, the check valve 43 is configured such that when the refrigerant flows from the second refrigerant introduction port 402 side to the first refrigerant discharge port 404 side, the valve body 431 is caused by the pressure of the refrigerant. The first refrigerant passage 18a is opened when the valve body 431 is separated from the valve seat portion 432 by being pressed toward the 404 side.

Subsequently, the second refrigerant passage 21 a introduces the refrigerant that has flowed out from the indoor evaporator 20 through the third refrigerant introduction port 403 that opens to the bottom wall of the body 40, and the introduced refrigerant opens to the side wall of the body 40. This is a refrigerant passage that leads to the accumulator 22 (the suction side of the compressor 11) via the refrigerant outlet 405.

The second refrigerant passage 21a of the present embodiment includes a passage extending in the radial direction (left and right direction on the paper surface) of the body 40 and a passage extending in the axial direction (up and down direction on the paper surface) of the body 40, The inside of the body 40 flows in an L shape.

Here, in the present embodiment, in order to promote heat exchange between the refrigerant flowing through the first refrigerant passage 18a and the refrigerant flowing through the second refrigerant passage 21a via the body 40, the refrigerant flowing through the first refrigerant passage 18a The refrigerant flowing in the two refrigerant passages 21a is opposed to the refrigerant. That is, in the second refrigerant passage 21a of the present embodiment, the flow direction of the refrigerant flowing through at least a part of the second refrigerant passage 21a is opposite to the flow direction of the refrigerant flowing through at least a part of the first refrigerant passage 18a. It is formed to become.

Specifically, the second refrigerant passage 21a of the present embodiment includes a second refrigerant passage 21a in which the flow direction of the refrigerant flowing through the passage extending in the radial direction of the body 40 is the first of the passages extending in the radial direction of the body 40 in the first refrigerant passage 18a. It is formed so as to be in a direction opposite to the flow direction of the refrigerant flowing through the passage on the side of the one refrigerant outlet 404.

In the second refrigerant passage 21a, a disc-shaped pressure adjusting valve body 441, a spring (elastic member) 442, a part of the second shaft 443, a plate member 443a, and the like are arranged.

The pressure adjusting valve body 441 changes the passage opening degree (passage area) of the second refrigerant passage 21a, whereby the pressure of the refrigerant flowing into the second refrigerant passage 21a (the pressure of the refrigerant flowing through the indoor evaporator 20). Is a valve body for maintaining a predetermined set pressure value.

The second shaft 443 is disposed so as to pass through a through hole 408 that allows the second refrigerant passage 21 a and the bypass passage 41 in the body 40 to communicate with each other, and one end side thereof is in contact with the recess of the bypass opening / closing valve body 421. The pressure adjusting valve body 441 is connected.

The pressure adjusting valve element 441 according to the present embodiment is in contact with the bypass opening / closing valve element 421 via the second shaft 443, and is displaced in conjunction with the displacement of the bypass opening / closing valve element 421.

Note that a seal member (seal portion) 408a that suppresses refrigerant leakage from a gap formed between the second shaft 443 and the through hole 408 is provided in the through hole 408 that allows the second refrigerant passage 21a and the bypass passage 41 to communicate with each other. Has been placed. The seal member 408a of the present embodiment is configured by a resin O-ring so as to function as a vibration absorbing member that absorbs vibration of the pressure adjusting valve body 441 in addition to the function of sealing the through hole 408. ing.

The plate member 443a is a plate-like member disposed on the third refrigerant introduction port 403 side, and the outermost peripheral side is fixed to the second refrigerant passage 21a by a connector 45 fixed to the third refrigerant introduction port 403. The plate member 443a has a plurality of through holes for circulating the refrigerant and a through hole that supports the other end of the second shaft 443. The connector 45 is a member that couples refrigerant piping to the third refrigerant introduction port 403, and is fixed to the third refrigerant introduction port 403 by caulking the body 40.

The spring 442 is constituted by a cylindrical coil spring extending in the axial direction of the body 40, and biases the pressure adjusting valve body 441 in a direction (valve closing direction) to press against the valve seat portion 407 formed in the second refrigerant passage 21a. Is configured to do.

Here, in the pressure adjustment valve body 441 of the present embodiment, the resultant force of the load (spring force) by the spring 442 and the pressure of the refrigerant flowing through the second refrigerant passage 21a (differential pressure before and after the pressure adjustment valve body 441). Acts on the valve closing side (upper side) of the pressure adjusting valve body 441.

For this reason, the drive motor 423 causes the motor axial force to act on the pressure adjusting valve body 441 so as to oppose (overcoming) the resultant force acting on the valve closing side (upper side) of the pressure adjusting valve body 441. Although not shown, the drive motor 423 has a conversion mechanism (feed screw mechanism) that converts the rotational motion of the motor into the vertical motion of the

shafts

422 and 443, and by adjusting the amount of rotation of the motor. The lift amount (displacement amount) of the pressure adjusting valve element 441 can be controlled.

Specifically, the pressure adjustment is performed by adjusting the rotation amount of the drive motor 423 so that the refrigerant pressure flowing into the second refrigerant passage 21a becomes a set pressure value (pressure at which frost formation on the indoor evaporator 20 does not occur). When the lift amount of the valve body 441 is changed, the pressure adjusting valve body 441 enters a function exhibiting state that exhibits a constant pressure maintaining function of maintaining the pressure of the refrigerant flowing into the second refrigerant passage 21a within the set pressure range.

On the other hand, when changing the lift amount of the pressure adjusting valve body 441 by adjusting the rotation amount of the drive motor 423 so that the refrigerant pressure before and after the pressure adjusting valve body 441 in the second refrigerant passage 21a does not change, the pressure adjustment The valve body 441 enters a function stop state where the constant pressure maintaining function is not exhibited.

Referring back to FIG. 1, the indoor air conditioning unit 30 will be described. The indoor air-conditioning unit 30 is disposed inside the instrument panel (instrument panel) at the forefront of the vehicle interior, and the blower 32, the above-described indoor condenser 12, and the indoor evaporator 20 are disposed in a casing 31 that forms the outer shell of the interior air conditioning unit 30. The heater core 34 and the like are accommodated.

The casing 31 forms an air passage for the air blown into the passenger compartment, and is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent in strength. An inside / outside air switching device 33 for switching and introducing vehicle interior air (inside air) and outside air is arranged on the most upstream side of the blown air flow in the casing 31.

The inside / outside air switching device 33 is formed with an inside air introduction port for introducing inside air into the casing 31 and an outside air introduction port for introducing outside air. Furthermore, inside / outside air switching device 33 is provided with an inside / outside air switching door that continuously adjusts the opening area of the inside air introduction port and the outside air introduction port to change the air volume ratio between the inside air volume and the outside air volume. Has been.

A blower 32 that blows air introduced through the inside / outside air switching device 33 toward the passenger compartment is disposed on the downstream side of the air flow of the inside / outside air switching device 33. The blower 32 is an electric blower that drives a centrifugal multiblade fan 32a by an electric motor 32b, and the number of rotations (the amount of blown air) is controlled by a control signal (control voltage) output from a control device described later. . The centrifugal multiblade fan 32a functions as a blower that blows air into the passenger compartment.

On the downstream side of the air flow of the blower 32, the indoor evaporator 20, the heater core 34, and the indoor condenser 12 are arranged in this order with respect to the flow of the air blown into the vehicle interior. In other words, the indoor evaporator 20 is disposed upstream of the indoor condenser 12 and the heater core 34 in the flow direction of the air blown into the vehicle interior.

Here, the heater core 34 is a heat exchanger for heating that exchanges heat between engine cooling water that outputs driving force for vehicle travel and air blown into the passenger compartment. In addition, the heater core 34 of this embodiment is arrange | positioned with respect to the indoor condenser 12 in the flow direction upstream of the vehicle interior ventilation air. Further, in the casing 31, a cold air bypass passage 35 is formed in which the air that has passed through the indoor evaporator 20 is caused to bypass the indoor condenser 12 and the heater core 34.

The air after passing through the indoor evaporator 20 passes through the indoor condenser 12 and the heater core 34 on the downstream side of the indoor evaporator 20 and on the upstream side of the indoor condenser 12 and the heater core 34. An air mix door 36 for adjusting the air volume ratio between the air to be passed and the air passing through the cold air bypass passage 35 is disposed. Further, on the downstream side of the air flow of the indoor condenser 12 and the downstream side of the air flow of the cold air bypass passage 35, a mixing space for mixing the air that has passed through the indoor condenser 12 and the air that has passed through the cold air bypass passage 35 is provided. ing.

Furthermore, on the most downstream side of the blown air flow of the casing 31, an air outlet (not shown) that blows the conditioned air mixed in the mixing space into the vehicle interior that is the air-conditioning target space is arranged. Specifically, as the air outlet, there are a face air outlet that blows air-conditioned air to the upper body of the passenger in the vehicle interior, a foot air outlet that blows air-conditioned air to the feet of the passenger, and a defroster that blows air-conditioned air to the inner side surface of the vehicle front window glass. There is an air outlet.

Therefore, by adjusting the air volume ratio between the air that the air mix door 36 passes through the indoor condenser 12 and the air that passes through the cold air bypass passage 35, the temperature of the conditioned air mixed in the mixing space is adjusted, The temperature of the conditioned air blown out from the air outlet is adjusted. The air mix door 36 is driven by a servo motor (not shown) that operates according to a control signal output from the control device.

Further, on the upstream side of the blower air flow of the face outlet, the foot outlet, and the defroster outlet, a face door (not shown) that adjusts the opening area of the face outlet, a foot door that adjusts the opening area of the foot outlet ( A defroster door (not shown) for adjusting the opening area of the defroster outlet is disposed.

These face doors, foot doors, and defroster doors constitute a blower outlet mode switching unit that switches a blower outlet mode, and are activated by a control signal output from a control device to be described later via a link mechanism or the like. Is driven by a servo motor (not shown).

Next, the electric control unit of this embodiment will be described. The control device 100 is composed of a well-known microcomputer including a CPU and memory (ROM, RAM, etc.) and its peripheral circuits, performs various calculations and processing based on a control program stored in the memory, Controls the operation of various connected control devices.

Further, on the input side of the control device 100, an inside air sensor that detects the vehicle interior temperature Tr, an outside air sensor that detects the outside air temperature Tam, a solar radiation sensor that detects the amount of solar radiation Ts in the vehicle interior, and the air blown from the indoor evaporator 20 An evaporator temperature sensor as an evaporator blowing temperature detection unit for detecting temperature (evaporator temperature) Te, a discharge temperature sensor for detecting the temperature Td of the refrigerant discharged from the compressor 11, and a blown air temperature TAV to be blown into the vehicle interior A sensor group for air conditioning control such as a blown air temperature sensor as a blown temperature detecting unit to be detected is connected.

Further, an operation panel (not shown) disposed near the instrument panel in front of the vehicle interior is connected to the input side of the control device 100, and operation signals from various operation switches provided on the operation panel are input. . Specifically, various operation switches provided on the operation panel include an operation switch of the vehicle air conditioner 1, a temperature setting switch for setting a set temperature in the vehicle interior, and a mode selection switch for selecting an operation mode of the heat pump cycle 10. Etc. are provided.

Note that the control device 100 is configured such that a control unit that controls the operation of various control devices connected to the output side thereof is integrally configured. The configuration (software and hardware) controls the operation of each control device. However, the control part which controls the action | operation of each control apparatus is comprised.

For example, in the present embodiment, the configuration in which the operation mode in the control device 100 is switched to the cooling mode, the first dehumidifying and heating mode, the second dehumidifying and heating mode, and the heating mode constitutes the operation mode switching unit 100a.

Further, in the present embodiment, in conjunction with the control of the bypass opening / closing valve 42 (drive motor 423) by the control device 100, a function exhibiting state in which the operating state of the pressure regulating valve 44 exhibits a constant pressure adjusting function, and a constant pressure adjusting function are provided. It is configured to switch to a function stop state that does not exhibit. For this reason, in this embodiment, the structure which controls the drive motor 423 of the bypass on-off valve 42 comprises the operation state switching part 100b.

Next, the operation of the vehicle air conditioner 1 of the present embodiment having the above configuration will be described. As described above, the vehicle air conditioner 1 of the present embodiment can be switched to the cooling mode for cooling the passenger compartment, the heating mode for heating the passenger compartment, and the dehumidifying and heating mode for heating while dehumidifying the passenger compartment.

In the vehicle air conditioner 1, when the operation switch of the operation panel is turned on, the control device 100 reads the detection signal of the sensor group and the operation signal of the operation panel.

Then, the control device 100 calculates a target blowing temperature TAO that is a target temperature of the blowing air blown into the vehicle interior based on the read detection signal and operation signal values based on the following formula F1.
TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × Ts + C (F1)
However, Tset is the vehicle interior set temperature set by the temperature setting switch, Tr is the vehicle interior temperature (inside air temperature) detected by the inside air sensor, Tam is the outside air temperature detected by the outside air sensor, and Ts is detected by the solar radiation sensor. The amount of solar radiation. Kset, Kr, Kam, Ks are control gains, and C is a correction constant.

Thereafter, the control device 100 determines the operating states of various control devices connected to the output side of the control device 100 according to the detection signal of the sensor group, the target blowing temperature TAO, and the operation mode selected by the mode selection switch. decide.

Hereinafter, the operation in each operation mode will be described.

(A) Heating Mode In the heating mode, the control device 100 opens the first low-pressure side passage 16 with the low-pressure side opening / closing valve 17 and closes the second low-pressure side passage 18 with the second expansion valve 19 (fully closed). . Further, the control device 100 displaces the bypass opening / closing valve element 421 to the closed position of the bypass passage 41 by the drive motor 423 and closes the bypass passage 41 by the bypass opening / closing valve 42.

Thereby, in the heat pump cycle 10, as shown by the black arrows in FIG. At this time, inside the integrated valve 4, as shown in FIG. 3, the pressure adjustment valve body 441 increases the passage opening of the second refrigerant passage 21a in conjunction with the displacement of the bypass opening / closing valve body 421. It is displaced to. That is, the operating state of the pressure adjustment valve 44 is a function stop state in which the constant pressure adjustment function is not exhibited.

With the configuration of the refrigerant flow path, the control device 100 determines a control signal to be output to various control devices based on the target blowing temperature TAO, the detection signal of the sensor group, and the like.

For example, the control signal output to the electric motor 11a of the compressor 11 is determined as follows. First, the target condenser temperature TCO of the indoor condenser 12 is determined with reference to a control map stored in advance in the memory of the control device 100 based on the target outlet temperature TAO.

Then, based on the deviation between the target condenser temperature TCO and the detected value of the discharge temperature sensor, the compressor 11 uses a feedback control method so that the temperature of the air blown into the passenger compartment approaches the target air temperature TAO. A control signal to be output to the electric motor 11a is determined.

As for the control signal output to the first expansion valve 14, a predetermined target is set so that the degree of supercooling of the refrigerant flowing into the first expansion valve 14 approaches the maximum coefficient of performance (COP) of the cycle. It is determined to approach the degree of supercooling.

As for the control signal output to the servo motor of the air mix door 36, the air mix door 36 closes the cold air bypass passage 35, and the total flow rate of the blown air after passing through the indoor evaporator 20 is the heater core 34 and the indoor condensation. To pass through the air passage of the vessel 12.

Then, the control signals determined as described above are output to various control devices. Thereafter, a control routine such as determination of operation states of various control devices → output of control signals and the like is repeated at predetermined intervals until the operation of the vehicle air conditioner 1 is requested by an operation switch or the like. Such a control routine is repeated in the other operation modes.

Therefore, in the heat pump cycle 10 in the heating mode, the high-pressure refrigerant discharged from the compressor 11 flows into the indoor condenser 12. The refrigerant that has flowed into the indoor condenser 12 exchanges heat with the vehicle interior blown air that has been blown from the blower 32 and passed through the indoor evaporator 20 to dissipate heat. Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 via the high-pressure side passage 13 and is decompressed and expanded by the first expansion valve 14 until it becomes a low-pressure refrigerant. The low-pressure refrigerant decompressed by the first expansion valve 14 flows into the outdoor heat exchanger 15 and absorbs heat from the outside air blown from the blower fan. The refrigerant that has flowed out of the outdoor heat exchanger 15 flows into the accumulator 22 through the first low-pressure side passage 16 and is separated into gas and liquid.

Then, the gas-phase refrigerant separated by the accumulator 22 is sucked from the suction side of the compressor 11 and compressed again by the compressor 11. Note that the liquid-phase refrigerant separated by the accumulator 22 is stored in the accumulator 22 as surplus refrigerant that is not necessary to exhibit the refrigeration capacity for which the cycle is required. Since the second low-pressure side passage 18 is closed by the second expansion valve 19, the refrigerant does not flow into the indoor evaporator 20.

As described above, in the heating mode, the heat of the high-pressure refrigerant discharged from the compressor 11 by the indoor condenser 12 is radiated to the vehicle interior blown air, and the heat of the cooling water is heated by the heater core 34 in the vehicle interior blown air. The heated vehicle interior blown air can be blown out into the vehicle interior. Thereby, heating of a vehicle interior is realizable.

(B) Cooling Mode In the cooling mode, the control device 100 closes the first low-pressure side passage 16 with the low-pressure side opening / closing valve 17 and opens the high-pressure side passage 13 with the first expansion valve 14. Further, the control device 100 displaces the bypass opening / closing valve element 421 to the closed position of the bypass passage 41 by the drive motor 423 and closes the bypass passage 41 by the bypass opening / closing valve 42.

Thereby, in the heat pump cycle 10, as indicated by the white arrow in FIG. 1, the refrigerant that has flowed out of the indoor condenser 12 is switched to the refrigerant flow path that flows in the order of the outdoor heat exchanger 15 and the indoor evaporator 20. More specifically, the refrigerant that has flowed out of the indoor condenser 12 passes through the first expansion valve 14 → the outdoor heat exchanger 15 → the second expansion valve 19 → the indoor evaporator 20 → the pressure regulating valve 44 → the accumulator 22 → the compressor 11. It flows in the order of the inhalation side. In the cooling mode, the outdoor heat exchanger 15 and the indoor evaporator 20 are connected in series with respect to the refrigerant flow.

At this time, inside the integrated valve 4, as shown in FIG. 3, the pressure adjustment valve body 441 increases the passage opening of the second refrigerant passage 21a in conjunction with the displacement of the bypass opening / closing valve body 421. It is displaced to. That is, the operating state of the pressure adjustment valve 44 is a function stop state in which the constant pressure adjustment function is not exhibited.

For example, the control signal output to the electric motor 11a of the compressor 11 is determined as follows. First, based on the target blowing temperature TAO, the target evaporator blowing temperature TEO of the blown air blown out from the indoor evaporator 20 is determined with reference to a control map stored in advance in the memory of the control device 100. Then, based on the deviation between the target evaporator blowout temperature TEO and the detected value of the evaporator temperature sensor, the temperature of the air that has passed through the indoor evaporator 20 using the feedback control method approaches the target blowout temperature TAO. A control signal output to the electric motor 11a of the compressor 11 is determined.

Further, the control signal output to the second expansion valve 19 is such that the degree of supercooling of the refrigerant flowing into the second expansion valve 19 approaches a target supercooling degree set in advance so that the COP approaches the maximum value. To be determined.

Regarding the control signal output to the servo motor of the air mix door 36, the air mix door 36 closes the air passage of the heater core 34 and the indoor condenser 12, and the total flow rate of the blown air after passing through the indoor evaporator 20. Is determined to pass through the cold air bypass passage 35.

Thereby, in the heat pump cycle 10 in the cooling mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

4, the high-pressure refrigerant (a1 point) discharged from the compressor 11 flows into the indoor condenser 12. At this time, since the air mix door 36 closes the air passages of the heater core 34 and the indoor condenser 12, the refrigerant flowing into the indoor condenser 12 slightly exchanges heat with the air blown into the vehicle interior, and the indoor condenser. 12 (point a1 → point a2 in FIG. 4).

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 via the high-pressure side passage 13. At this time, since the first expansion valve 14 fully opens the high-pressure side passage 13, the refrigerant flowing out from the indoor condenser 12 flows into the outdoor heat exchanger 15 without being depressurized by the first expansion valve 14. To do. Then, the refrigerant flowing into the outdoor heat exchanger 15 radiates heat to the outside air blown from the blower fan in the outdoor heat exchanger 15 (point a2 → point a3 in FIG. 4).

The refrigerant that has flowed out of the outdoor heat exchanger 15 flows into the second expansion valve 19 via the second low-pressure side passage 18, and is decompressed and expanded until it becomes a low-pressure refrigerant in the second expansion valve 19 (FIG. 4). A3 point → a4 point). The low-pressure refrigerant decompressed by the second expansion valve 19 flows into the indoor evaporator 20 and absorbs heat from the air blown from the vehicle interior blown from the blower 32 to evaporate (point a4 → a5 in FIG. 4). Thereby, vehicle interior blowing air is cooled.

The refrigerant that has flowed out of the indoor evaporator 20 flows into the pressure adjustment valve 44. At this time, since the pressure adjustment valve 44 is in a function stop state in which the constant pressure adjustment function is not exhibited, the refrigerant flowing out of the indoor evaporator 20 is not adjusted to the set pressure value by the pressure adjustment valve 44. , Flows into the accumulator 22. Then, the refrigerant flowing into the accumulator 22 is separated into a gas phase refrigerant and a liquid phase refrigerant, and the separated gas phase refrigerant is sucked from the suction side of the compressor 11 and compressed again by the compressor 11.

As described above, in the cooling mode, since the air passages of the indoor condenser 12 and the heater core 34 are closed by the air mix door 36, the air blown into the vehicle interior is blown out into the vehicle interior. Can do. Thereby, cooling of a vehicle interior is realizable.

In the cooling mode, the pressure regulating valve 44 disposed on the outlet side of the indoor evaporator 20 does not function so as to keep the refrigerant pressure on the outlet side of the indoor evaporator 20 constant, so that the refrigerant evaporation pressure in the indoor evaporator 20 is reduced. The pressure can be lowered below the set pressure value.

Therefore, the refrigerant pressure on the outlet side of the indoor evaporator 20 can be adjusted to a pressure required for ensuring the target cooling capacity without causing control interference between the compressor 11 and the pressure regulating valve 44.

Here, in the cooling mode, a high-temperature high-pressure refrigerant flows through the first refrigerant passage 18a inside the integrated valve 4, and the pressure is reduced by the second expansion valve 19 through the second refrigerant passage 21a inside the integrated valve 4. A low-temperature, low-pressure refrigerant circulates. As a result, the ambient temperature of the first refrigerant passage 18a in the body 40 is about 30 ° C. to 60 ° C., and the ambient temperature of the second refrigerant passage 21a in the body 40 is about 0 ° C. to 10 ° C.

In the present embodiment, since the first refrigerant passage 18 a and the second refrigerant passage 21 a are formed in the common body 40, the refrigerant flowing through the first refrigerant passage 18 a and the second refrigerant passage 21 a passes through the body 40. Heat exchange indirectly.

In particular, in the present embodiment, since the refrigerant flowing through at least a part of the first refrigerant passage 18a and the second refrigerant passage 21a is used as a counterflow, heat exchange via the body 40 can be promoted.

As a result, as shown in FIG. 5, the degree of supercooling of the refrigerant on the outlet side of the outdoor heat exchanger 15 is increased by heat exchange between the refrigerant flowing out of the outdoor heat exchanger 15 and the refrigerant flowing out of the indoor evaporator 20. Since the enthalpy difference between the inlet and the outlet of the indoor evaporator 20 is increased, the cooling capacity is improved. As a result, since the cooling capacity can be secured with a small refrigerant flow rate, it is possible to reduce the number of revolutions of the compressor 11 in the cooling mode and to save power in the heat pump cycle 10.

(C) First dehumidifying and heating mode The first dehumidifying and heating mode is a dehumidifying and heating mode in which the temperature adjustment range is a wide range from a low temperature range to a high temperature range. For example, in a state where the dehumidification heating mode is selected by a mode selection switch. This is executed when the temperature difference (= TAV-TAO) between the target blowing temperature TAO and the blowing air temperature TAV is equal to or less than a predetermined value.

In the first dehumidifying and heating mode, the control device 100 closes the first low-pressure side passage 16 by the low-pressure side opening / closing valve 17 and sets the first and

second expansion valves

14 and 19 to the throttle state or the fully open state. Further, the control device 100 displaces the bypass opening / closing valve element 421 to the closed position of the bypass passage 41 by the drive motor 423 and closes the bypass passage 41 by the bypass opening / closing valve 42.

Thereby, the heat pump cycle 10 is switched to the refrigerant flow path through which the refrigerant flows, as indicated by the white horizontal arrows in FIG. 1, as in the cooling mode. In the first dehumidifying and heating mode, as in the cooling mode, the outdoor heat exchanger 15 and the indoor evaporator 20 are connected in series with respect to the refrigerant flow.

For example, the control signal output to the electric motor 11a of the compressor 11 is determined in the same manner as in the cooling mode. As for the control signal output to the servo motor of the air mix door 36, the air mix door 36 closes the cold air bypass passage 35, and the total flow rate of the blown air after passing through the indoor evaporator 20 is the heater core 34 and the indoor condensation. To pass through the air passage of the vessel 12.

Further, the first expansion valve 14 and the second expansion valve 19 are changed according to the target blowing temperature TAO that is the target temperature of the blowing air blown into the vehicle interior. Specifically, the control device 100 decreases the passage area of the high-pressure side passage 13 at the first expansion valve 14 as the target blowing temperature TAO, which is the target temperature of the blowing air blown into the vehicle interior, increases. The second expansion valve 19 increases the passage area of the second low-pressure side passage 18. Thereby, in the 1st dehumidification heating mode, the mode of four steps from the 1st mode to the 4th mode is performed.

(C-1) First Mode The first mode is executed, for example, when the target blowing temperature TAO is equal to or lower than a predetermined first reference temperature in the first dehumidifying and heating mode.

In the first mode, the high pressure side passage 13 is fully opened by the first expansion valve 14 and the second expansion valve 19 is in the throttle state. Therefore, although the cycle configuration (refrigerant flow path) is the same refrigerant flow path as in the cooling mode, the air mix door 36 fully opens the air passage on the indoor condenser 12 and heater core 34 side. The high-pressure refrigerant is dissipated by both the outdoor heat exchanger 12 and the outdoor heat exchanger 15.

That is, the high-pressure refrigerant discharged from the compressor 11 flows into the indoor condenser 12 and radiates heat by exchanging heat with the air blown into the passenger compartment after being cooled and dehumidified by the indoor evaporator 20. Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 via the high-pressure side passage 13. At this time, since the first expansion valve 14 fully opens the high-pressure side passage 13, the refrigerant flowing out from the indoor condenser 12 flows into the outdoor heat exchanger 15 without being depressurized by the first expansion valve 14. To do. The refrigerant flowing into the outdoor heat exchanger 15 radiates heat to the outside air blown from the blower fan in the outdoor heat exchanger 15.

The refrigerant that has flowed out of the outdoor heat exchanger 15 flows into the second expansion valve 19 via the second low-pressure side passage 18 and is decompressed and expanded at the second expansion valve 19 until it becomes a low-pressure refrigerant. The low-pressure refrigerant decompressed by the second expansion valve 19 flows into the indoor evaporator 20, absorbs heat from the air blown from the vehicle interior blown from the blower 32, and evaporates. Thereby, vehicle interior blowing air is cooled.

Then, the refrigerant that has flowed out of the indoor evaporator 20 flows from the pressure adjustment valve 44 to the accumulator 22 to the suction side of the compressor 11 and is compressed by the compressor 11 again, as in the cooling mode. At this time, since the pressure adjustment valve 44 is in a function stop state in which the constant pressure adjustment function is not exhibited, the refrigerant flowing out of the indoor evaporator 20 is not adjusted to the set pressure value by the pressure adjustment valve 44.

As described above, in the first mode of the first dehumidifying and heating mode, the vehicle interior blown air cooled and dehumidified by the indoor evaporator 20 can be heated by the indoor condenser 12 and blown out into the vehicle interior. Thereby, dehumidification heating of a vehicle interior is realizable.

(C-2) Second Mode The second mode is when the target outlet temperature TAO is higher than the first reference temperature and lower than or equal to the second reference temperature set in advance to a value higher than the first reference temperature. Executed. In the second mode, the first expansion valve 14 is set in the throttle state, and the throttle opening degree of the second expansion valve 19 (the passage area of the second low-pressure side passage 18) is set in the throttle state increased compared to that in the first mode. Therefore, in the second mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 6, the high-pressure refrigerant (b5 point) discharged from the compressor 11 flows into the indoor condenser 12 and is cooled by the indoor evaporator 20 and dehumidified in the vehicle interior. Heat exchange is performed to dissipate heat (b1 point → b2 point in FIG. 6). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 via the high-pressure side passage 13 and is depressurized until it becomes an intermediate-pressure refrigerant (point b2 → b3 in FIG. 6). Then, the intermediate-pressure refrigerant decompressed by the first expansion valve 14 flows into the outdoor heat exchanger 15 and dissipates heat to the outside air blown from the blower fan (b3 point → b4 point in FIG. 6).

The refrigerant that has flowed out of the outdoor heat exchanger 15 flows into the second expansion valve 19 via the second low-pressure side passage 18, and is decompressed and expanded until it becomes a low-pressure refrigerant in the second expansion valve 19 (FIG. 6). B4 point → b5 point). The low-pressure refrigerant depressurized by the second expansion valve 19 flows into the indoor evaporator 20, absorbs heat from the air blown from the vehicle interior blown from the blower 32, and evaporates (b5 point → b6 point in FIG. 6). Thereby, vehicle interior blowing air is cooled.

Then, the refrigerant flowing out of the indoor evaporator 20 flows again from the pressure regulating valve 44 → accumulator 22 → the suction side of the compressor 11 which is in a function stop state in which the constant pressure regulating function is not performed, similarly to the cooling mode. It is compressed by the compressor 11.

As described above, during the second mode of the first dehumidifying and heating mode, the vehicle interior blown air cooled and dehumidified by the indoor evaporator 20 is heated by the indoor condenser 12 in the same manner as in the first mode. Can be blown out. Thereby, dehumidification heating of a vehicle interior is realizable.

At this time, since the first expansion valve 14 is in the throttle state in the second mode, the temperature of the refrigerant flowing into the outdoor heat exchanger 15 can be lowered compared to the first mode. Therefore, the temperature difference between the refrigerant temperature and the outside air temperature in the outdoor heat exchanger 15 can be reduced, and the heat radiation amount of the refrigerant in the outdoor heat exchanger 15 can be reduced.

As a result, the amount of heat released from the refrigerant in the indoor condenser 12 can be increased without increasing the refrigerant circulation flow rate that circulates the cycle in the first mode, and the refrigerant is blown out from the indoor condenser 12 than in the first mode. The temperature of the blown air can be increased.

(C-3) Third Mode The third mode is when the target outlet temperature TAO is higher than the second reference temperature and lower than or equal to the third reference temperature set in advance to a value higher than the second reference temperature. Executed. In the third mode, the throttle opening of the first expansion valve 14 (passage area of the high-pressure side passage 13) is made smaller than that in the second mode, and the throttle opening of the second expansion valve 19 (second low pressure) The throttle area is set such that the passage area of the side passage 18 is larger than that in the second mode. Therefore, in the third mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 7, the high-pressure refrigerant (point c1) discharged from the compressor 11 flows into the indoor condenser 12 and is cooled by the indoor evaporator 20 and dehumidified in the vehicle interior. The heat is exchanged to dissipate heat (point c1 → c2 in FIG. 7). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 via the high-pressure side passage 13 and is depressurized until it becomes an intermediate-pressure refrigerant having a temperature lower than the outside air temperature (point c2 → c3 in FIG. 7). point). Then, the intermediate pressure refrigerant decompressed by the first expansion valve 14 flows into the outdoor heat exchanger 15 and absorbs heat from the outside air blown from the blower fan (point c3 → point c4 in FIG. 7).

The refrigerant that has flowed out of the outdoor heat exchanger 15 flows into the second expansion valve 19 via the second low-pressure side passage 18, and is decompressed and expanded until it becomes a low-pressure refrigerant in the second expansion valve 19 (FIG. 7). C4 point → c5 point). The low-pressure refrigerant decompressed by the second expansion valve 19 flows into the indoor evaporator 20 and absorbs heat from the air blown from the vehicle interior blown from the blower 32 to evaporate (point c5 → point c6 in FIG. 7). Thereby, vehicle interior blowing air is cooled.

As described above, during the third mode of the first dehumidifying and heating mode, the vehicle interior blown air cooled by the indoor evaporator 20 and dehumidified is heated by the indoor condenser 12 in the same manner as in the first and second modes. Can be blown into the passenger compartment. Thereby, dehumidification heating of a vehicle interior is realizable.

At this time, in the third mode, the outdoor heat exchanger 15 is caused to function as a heat absorber (evaporator) by reducing the throttle opening of the first expansion valve 14, so that the indoor condenser is more than in the second mode. The temperature blown from 12 can be raised.

As a result, with respect to the second mode, the suction refrigerant density of the compressor 11 can be increased, and the heat release amount of the refrigerant in the indoor condenser 12 without increasing the rotation speed (refrigerant discharge capacity) of the compressor 11. Can be increased, and the temperature of the blown-out air blown out from the indoor condenser 12 can be increased more than in the second mode.

(C-4) Fourth Mode The fourth mode is executed when the target outlet temperature TAO becomes higher than the third reference temperature. In the fourth mode, the throttle opening state (passage area of the high-pressure side passage 13) of the first expansion valve 14 is made smaller than that in the third mode, and the second low-pressure side passage 18 is set by the second expansion valve 19. Is fully open. Therefore, in the fourth mode, the state of the refrigerant circulating in the cycle changes as shown in the Mollier diagram of FIG.

That is, as shown in FIG. 8, the high-pressure refrigerant (point d1) discharged from the compressor 11 flows into the indoor condenser 12, and is cooled by the indoor evaporator 20 and dehumidified in the vehicle interior. Heat exchange is performed to dissipate heat (point d1 → d2 in FIG. 8). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 through the high-pressure side passage 13 and is depressurized until it becomes a low-pressure refrigerant (point d2 → point d3 in FIG. 8). The low-pressure refrigerant decompressed by the first expansion valve 14 flows into the outdoor heat exchanger 15 and absorbs heat from the outside air blown from the blower fan (point d3 → point d4 in FIG. 8).

The refrigerant flowing out of the outdoor heat exchanger 15 flows into the second expansion valve 19 through the second low-pressure side passage 18. At this time, since the second expansion valve 19 fully opens the second low-pressure side passage 18, the refrigerant flowing out of the outdoor heat exchanger 15 is not decompressed by the second expansion valve 19, and the indoor evaporator 20 Flow into.

The low-pressure refrigerant that has flowed into the indoor evaporator 20 absorbs heat from the air blown from the vehicle interior blown from the blower 32 and evaporates (point d4 → point d5 in FIG. 8). Thereby, vehicle interior blowing air is cooled. Then, the refrigerant flowing out of the indoor evaporator 20 flows again from the pressure regulating valve 44 → accumulator 22 → the suction side of the compressor 11 which is in a function stop state in which the constant pressure regulating function is not performed, similarly to the cooling mode. It is compressed by the compressor 11.

As described above, in the fourth mode of the first dehumidifying and heating mode, the vehicle interior blown air cooled and dehumidified by the indoor evaporator 20 is heated by the indoor condenser 12 as in the first to third modes. Can be blown into the passenger compartment. Thereby, dehumidification heating of a vehicle interior is realizable.

At this time, in the fourth mode, as in the third mode, the outdoor heat exchanger 15 can function as a heat absorber (evaporator), and the throttle opening degree of the first expansion valve 14 can be set higher than that in the third mode. Since it is reduced, the refrigerant evaporation temperature in the outdoor heat exchanger 15 can be lowered. Therefore, the temperature difference between the refrigerant temperature and the outside air temperature in the outdoor heat exchanger 15 can be increased more than in the third mode, and the heat absorption amount of the refrigerant in the outdoor heat exchanger 15 can be increased.

As a result, with respect to the third mode, the suction refrigerant density of the compressor 11 can be increased, and the heat release amount of the refrigerant in the indoor condenser 12 without increasing the rotation speed (refrigerant discharge capacity) of the compressor 11. And the temperature of the air blown out from the indoor condenser 12 can be increased more than in the third mode.

As described above, in the first dehumidifying and heating mode, the temperature of the blown-out air blown into the vehicle interior is changed to a low temperature range by changing the throttle opening degree of the first expansion valve 14 and the second expansion valve 19 in accordance with the target blowing temperature TAO. To a high temperature range.

In other words, in the first dehumidifying and heating mode, while switching the outdoor heat exchanger 15 from a state where it functions as a radiator that radiates the refrigerant to a state where it functions as an evaporator that absorbs heat from the refrigerant, the refrigerant in the outdoor heat exchanger 15 is changed. The amount of heat release or the amount of heat absorption can be adjusted.

Therefore, the amount of heat released from the refrigerant in the indoor condenser 12 can be adjusted in a wider range than the cycle configuration in which the outdoor heat exchanger 15 functions as either a radiator or an evaporator, and the air-conditioning target space can be adjusted during the dehumidifying operation. The temperature adjustment range of the blown air blown out to can be expanded.

In the first dehumidifying and heating mode, as in the cooling mode, the pressure regulating valve 44 disposed on the outlet side of the indoor evaporator 20 does not function to maintain the refrigerant pressure on the outlet side of the indoor evaporator 20 constant. Thus, the refrigerant evaporation pressure in the indoor evaporator 20 can be reduced to a set pressure value or less.

(D) Second dehumidifying heating mode The second dehumidifying heating mode is a dehumidifying heating mode in which the temperature adjustment range is higher than the first dehumidifying heating mode. For example, the dehumidifying heating mode is selected by the mode selection switch. This is executed when the temperature difference (= TAV−TAO) between the target blowing temperature TAO and the blowing air temperature TAV is greater than a predetermined value.

In the second dehumidifying and heating mode, the control device 100 opens the first low-pressure side passage 16 by the low-pressure side opening / closing valve 17 and sets the first and

second expansion valves

14 and 19 to the throttle state. Further, as shown in FIG. 2, the control device 100 displaces the bypass opening / closing valve body 421 to the open position of the bypass passage 41 by the drive motor 423 to open the bypass passage 41 and to open the pressure adjusting valve body 441. The pressure of the refrigerant flowing into the second refrigerant passage 21a (the refrigerant pressure on the outlet side of the indoor evaporator 20) is displaced so as to become the set pressure value. Thereby, the operating state of the pressure adjusting valve 44 becomes a function exhibiting state in which the constant pressure adjusting function is exhibited.

Therefore, in the heat pump cycle 10, the refrigerant flowing out of the indoor condenser 12 is switched to the refrigerant flow path that flows to both the outdoor heat exchanger 15 and the indoor evaporator 20, as indicated by the white oblique arrows in FIG. 1. More specifically, the refrigerant flowing out of the indoor condenser 12 flows from the first expansion valve 14 to the outdoor heat exchanger 15 → the accumulator 22 → the suction side of the compressor 11 and at the same time, the second expansion valve 19 → the indoor evaporation. It flows in the order of the vessel 20 → the pressure regulating valve 44 → the accumulator 22 → the suction side of the compressor 11. In the second dehumidifying and heating mode, the outdoor heat exchanger 15 and the indoor evaporator 20 are connected in parallel to the refrigerant flow.

Further, the control signals output to the first expansion valve 14 and the second expansion valve 19 are determined so as to have a predetermined opening for the second dehumidifying / heating mode.

Regarding the control signal output to the drive motor 423 of the integrated valve 4, the bypass opening / closing valve element 421 is displaced to the open position of the bypass passage 41 and the pressure adjusting valve element 441 is disposed on the outlet side of the indoor evaporator 20. The refrigerant pressure is determined to be displaced so as to become a set pressure value. Specifically, when the refrigerant pressure on the outlet side of the indoor evaporator 20 falls below the set pressure value, the passage opening (passage area) of the second refrigerant passage 21a decreases (throttle opening decreases), and the outlet of the indoor evaporator 20 When the refrigerant pressure on the side exceeds the set pressure value, the control signal output to the drive motor 423 of the integrated valve 4 is determined so that the passage area of the second refrigerant passage 21a increases.

Therefore, in the heat pump cycle 10 in the second dehumidifying heating mode, as shown in the Mollier diagram of FIG. 9, the high-pressure refrigerant (point e1) discharged from the compressor 11 flows into the indoor condenser 12 and Heat is exchanged with the air blown into the passenger compartment that has been cooled and dehumidified by the evaporator 20 to radiate heat (point e1 → point e2 in FIG. 9). Thereby, vehicle interior blowing air is heated.

The refrigerant that has flowed out of the indoor condenser 12 flows into the first expansion valve 14 through the high-pressure side passage 13 and flows into the second expansion valve 19 through the bypass passage 41. The high-pressure refrigerant flowing into the first expansion valve 14 is depressurized until it becomes a low-pressure refrigerant (point e2 → point e3 in FIG. 9). The low-pressure refrigerant decompressed by the first expansion valve 14 flows into the outdoor heat exchanger 15 and absorbs heat from the outside air blown from the blower fan (point e3 → point e5 in FIG. 9).

On the other hand, the high-pressure refrigerant flowing into the second expansion valve 19 is depressurized until it becomes a low-pressure refrigerant so that the degree of superheat on the outlet side approaches the target degree of superheat (point e2 → point e4 in FIG. 9). Then, the low-pressure refrigerant decompressed by the second expansion valve 19 flows into the indoor evaporator 20 and absorbs heat from the air blown from the vehicle interior blown from the blower 32 to evaporate (point e4 → point e6 in FIG. 9). ). Thereby, vehicle interior blowing air is cooled. Note that the pressure of the refrigerant in the indoor evaporator 20 is adjusted to a constant pressure by the pressure adjustment valve 44.

The refrigerant flowing out of the outdoor heat exchanger 15 and the refrigerant flowing out of the indoor evaporator 20 merge on the inlet side of the accumulator 22 (e5 point → e7 point, e6 point → e7 point in FIG. 9), and the accumulator 22 → compressor. 11 flows to the suction side and is compressed again by the compressor 11. In addition, since the check valve 43 is provided in the second low-pressure side passage 18, the refrigerant does not flow backward from the bypass passage 41 to the outlet side of the outdoor heat exchanger 15.

As described above, in the second dehumidifying / heating mode, unlike the first dehumidifying / heating mode, the outdoor heat exchanger 15 and the indoor evaporator 20 are connected in parallel to the refrigerant flow.

And in the 2nd dehumidification heating mode, since the pressure regulation valve 44 arrange | positioned at the exit side of the indoor evaporator 20 functions so that the refrigerant | coolant pressure on the exit side of the indoor evaporator 20 may be maintained constant, as shown in FIG. The refrigerant evaporation pressure in the outdoor heat exchanger 15 can be made lower than the refrigerant evaporation pressure in the indoor evaporator 20.

Therefore, the refrigerant evaporating pressure in the indoor evaporator 20 is maintained at a predetermined value or more, and the occurrence of frost (frost) in the indoor evaporator 20 is suppressed, and the refrigerant in the outdoor heat exchanger 15 is suppressed. The amount of heat absorbed can be increased to increase the amount of heat released from the refrigerant in the indoor condenser 12. As a result, the temperature adjustment range can be expanded to the side that increases the temperature of the blown-out air that is blown into the vehicle interior in the second dehumidifying and heating mode.

Here, in the second dehumidifying and heating mode, high-temperature high-pressure refrigerant flows through the first refrigerant passage 18a inside the integrated valve 4, and the second expansion valve 19 passes through the second refrigerant passage 21a inside the integrated valve 4. A low-temperature low-pressure refrigerant whose pressure has been reduced flows. As a result, the ambient temperature of the first refrigerant passage 18a in the body 40 is about 30 ° C. to 50 ° C., and the ambient temperature of the second refrigerant passage 21a in the body 40 is about 0 ° C. to 5 ° C.

Accordingly, as shown in FIG. 10, heat exchange between the refrigerant that has flowed out of the indoor condenser 12 and the refrigerant that has flowed out of the indoor evaporator 20 increases the amount of heat absorbed in the entire heat pump cycle 10, and thus the high pressure of the heat pump cycle 10. Side pressure rises. As a result, since the heating capacity can be secured with a small refrigerant flow rate, the rotational speed of the compressor 11 in the second dehumidifying and heating mode can be reduced, and the power saving of the heat pump cycle 10 can be achieved.

In the vehicle air conditioner 1 of the present embodiment described above, as described above, by switching the refrigerant flow path of the heat pump cycle 10, by performing appropriate cooling, heating, and dehumidification heating in the vehicle interior, Comfortable air conditioning can be realized.

In the vehicle air conditioner 1 according to the present embodiment, as the dehumidifying and heating mode, the heat exchange capacity (heat radiation capacity and heat absorption capacity) in the outdoor heat exchanger 15 is adjusted, and the blown air blown into the vehicle compartment extends from the low temperature range to the high temperature range. It is possible to switch between a first dehumidifying and heating mode in which the temperature can be adjusted over a wide range and a second dehumidifying and heating mode in which the temperature of the blown air blown into the vehicle compartment can be adjusted in a high temperature range as compared with the first dehumidifying and heating mode.

Therefore, the temperature adjustable range of the air blown into the passenger compartment, which is the air conditioning target space, can be expanded.

Further, since the first dehumidifying / heating mode and the second dehumidifying / heating mode can be switched by a simple configuration such as the low pressure side opening / closing valve 17 and the bypass opening / closing valve 42, the temperature adjustment range of the blown air into the passenger compartment is expanded. The configuration to be realized can be realized concretely and easily.

In particular, in the heat pump cycle 10 of the present embodiment, the refrigerant pressure on the outlet side of the indoor evaporator 20 is maintained at the set pressure value by the pressure regulating valve 44 in the second dehumidifying and heating mode (parallel operation mode). Therefore, the heat absorption amount of the refrigerant in the indoor evaporator 20 and the heat absorption amount of the refrigerant in the outdoor heat exchanger 15 can be appropriately changed.

Further, in the cooling mode and the first dehumidifying and heating mode (series operation mode), the refrigerant pressure on the outlet side of the indoor evaporator 20 is not maintained at the set pressure value by the pressure adjustment valve 44. Without causing control interference of the compressor 11, the refrigerant pressure on the outlet side of the indoor evaporator 20 can be adjusted to a pressure required to secure a target cooling capacity.

Therefore, the heat absorption amounts of the indoor evaporator 20 and the outdoor heat exchanger 15 in the parallel operation mode can be appropriately changed, and the cooling capacity in the serial operation mode can be appropriately adjusted.

In addition to this, in the present embodiment, the bypass opening / closing valve 42, the check valve 43, the pressure adjusting valve 44, and the like are accommodated in the common body 40, and the displacement of the bypass passage 41 of the bypass opening / closing valve body 421 is accommodated. In conjunction with this, the integrated valve 4 that can displace the pressure regulating valve body 441 is employed. For this reason, simplification of the cycle configuration of the heat pump cycle 10 can be achieved.

In addition, the integrated valve 4 of the present embodiment is configured to displace the pressure adjusting valve element 441 in conjunction with the displacement of the bypass opening / closing valve element 421, so that a drive motor can be used without using a bellows dedicated to pressure adjustment. The displacement amount of the pressure adjusting valve body 441 can be adjusted at 423, and the cycle configuration of the heat pump cycle 10 can be realized with a simpler configuration.

In the integrated valve 4 according to the present embodiment, the vibration of the pressure regulating valve body 441 is absorbed by the seal member 408a provided in the through hole 408 that allows the first refrigerant passage 18a and the second refrigerant passage 21a to communicate with each other. It is said. As a result, when the pressure adjusting valve body 441 is displaced so that the refrigerant pressure on the outlet side of the indoor evaporator 20 is maintained at the set pressure value, a difference due to valve vibration in the low opening range of the pressure adjusting valve body 441 is obtained. Sound generation can be effectively suppressed.

In the present embodiment, the example in which the seal member 408a is formed of a resin O-ring has been described, but the present invention is not limited to this. In the case where the displacement amount of the pressure adjusting valve body 441 is large and there is a concern about wear of the seal member 408a due to sliding of the second shaft 443, as shown in FIG. 11, the seal member 408b has durability such as wear. You may comprise by the member (for example, bellows) excellent in.

Furthermore, in the integrated valve 4 of the present embodiment, the bypass opening / closing valve element 421 can be arbitrarily displaced between the closed position and the open position of the bypass passage 41 by the drive motor 423. Accordingly, when the bypass passage 41 is opened, the bypass opening / closing valve element 421 can be gradually displaced from the closed position to the open position, and the refrigerant injection sound that is likely to occur when the bypass passage 41 is opened is effective. Can be suppressed.

In the integrated valve 4 of the present embodiment, since the first refrigerant passage 18a and the second refrigerant passage 21a are formed in the common body 40, the indoor condenser 12 or the internal heat exchanger can be provided without providing a dedicated internal heat exchanger. Heat can be exchanged between the refrigerant flowing out of the outdoor heat exchanger 15 and the refrigerant flowing out of the indoor evaporator 20.

This makes it possible to reduce the work of the compressor 11 in the cooling mode or the like while simplifying the heat pump cycle 10 and to realize power saving of the heat pump cycle 10. At this time, the refrigerant flows in a part of the first refrigerant passage 18a and the second refrigerant passage 21a so that the refrigerant flows in an opposite flow. Therefore, the refrigerant flowing through the first refrigerant passage 18a and the refrigerant flowing through the second refrigerant passage 21a The internal heat exchange via the body 40 can be effectively promoted.

(Second Embodiment)
Next, a second embodiment will be described. This embodiment demonstrates the example which changed the internal structure of the integrated valve 4 with respect to 1st Embodiment. In the present embodiment, description of the same or equivalent parts as in the first embodiment will be omitted or simplified.

As shown in FIGS. 12 and 13, the second refrigerant passage 21 a in the integrated valve 4 of the present embodiment introduces the refrigerant that has flowed out from the indoor evaporator 20 through the third refrigerant introduction port 403 that opens in the side wall of the body 40. The introduced refrigerant is guided to the accumulator 22 via a second refrigerant outlet 405 that opens to the bottom wall of the body 40.

In the second refrigerant passage 21a, a pressure adjusting valve body 441, a spring 442, a part of the second shaft 443, a plate member 443a, a bellows 444 and the like are arranged.

The second shaft 443 of this embodiment is connected to the pressure adjusting valve body 441 in a state where one end side is located in the recess of the bypass opening / closing valve body 421, and the bypass opening / closing valve body 421 is displaced to the closed position. At this time, the pressure adjusting valve element 441 is pressed against the bypass opening / closing valve element 421 so as to increase the passage opening (passage area) of the second refrigerant passage 21a.

If the second shaft 443 presses the pressure regulating valve body 441 when the bypass opening / closing valve body 421 is displaced to the closed position in this way, the function of not exerting the constant pressure maintaining function by the pressure regulating valve body 441. It can be in a stopped state.

Specifically, the second shaft 443 contacts the bypass opening / closing valve element 421 when the bypass opening / closing valve element 421 is displaced to the closed position, and bypasses when the bypass opening / closing valve element 421 is displaced to the open position. The length in the axial direction is set so as to be separated from the opening / closing valve body 421.

The bellows 444 is a hollow cylindrical member formed to be extendable and contractable in the axial direction of the body 40. One end of the bellows 444 in the axial direction is connected to the plate member 443a, and the other end in the axial direction is a pressure adjusting valve body 441. It is connected to.

The bellows 444, together with the spring 442 disposed in the inner space of the bellows 444, applies a load that urges the pressure adjusting valve body 441 in the direction of pressing the valve seat 407 side. The load urged by the bellows 444 and the spring 442 to the pressure adjusting valve body 441 can be adjusted by an adjusting screw 445.

Therefore, in a state where the pressure adjusting valve body 441 is not pressed by the second shaft 443, that is, in a state where the bypass opening / closing valve body 421 is displaced to the open position, the following formula F2 is satisfied. A displacement amount (lift amount) ΔL is determined.
P1 × Ap = P2 × (Ap−Ab) + Fo + K × ΔL (F2) where “P1” is the refrigerant pressure upstream of the pressure regulating valve body 441 in the second refrigerant passage 21a (on the outlet side of the indoor evaporator 20). Refrigerant pressure), “P2” indicates the refrigerant pressure downstream of the pressure adjusting valve body 441 in the second refrigerant passage 21a. “Ap” is the pressure receiving surface of the pressure adjusting valve body 441, “Ab” is the cross-sectional area of the bellows 444, “Fo” is the initial load of the bellows 444 and the spring 442, and “K” is the total of the bellows 444 and the spring 442. The spring constant is shown.

As is clear from the above formula F2, by setting the difference between “Ap” and “Ab” to be small, the refrigerant pressure P1 on the inlet side of the second refrigerant passage 21a and the displacement amount ΔL are proportional to each other. For example, when P1 decreases, ΔL decreases, and the decrease in P1 is suppressed. As a result, the refrigerant pressure P1 on the inlet side of the second refrigerant passage 21a can be maintained at a predetermined set pressure value.

Therefore, even if the integrated valve 4 having the internal configuration shown in FIGS. 12 and 13 is adopted, the pressure adjusting valve body 441 is displaced in conjunction with the displacement of the bypass opening / closing valve body 421 by the single drive motor 423. It becomes possible to make it.

The control device 100 of the present embodiment is driven so that the bypass opening / closing valve element 421 is displaced to the closed position of the bypass passage 41 as shown in FIG. 13 in the heating mode, the cooling mode, and the first dehumidifying heating mode. The motor 423 is controlled. As a result, the pressure adjusting valve element 441 is pressed by the second shaft 443 so that the passage opening degree of the second refrigerant passage 21a is increased, and the function stop state in which the pressure adjusting valve element 441 does not perform the constant pressure maintaining function. Become.

On the other hand, the control device 100 controls the drive motor 423 so that the bypass opening / closing valve element 421 is displaced to the closed position of the bypass passage 41 in the second dehumidifying and heating mode, as shown in FIG. As a result, the second shaft 443 is separated from the bypass opening / closing valve body 421, and the pressure adjusting valve body 441 enters a function exhibiting state in which a constant pressure maintaining function is exhibited.

Other configurations and operations are the same as those in the first embodiment. Therefore, even if the integrated valve 4 having the internal configuration described in the present embodiment is adopted, the endothermic amounts of the indoor evaporator 20 and the outdoor heat exchanger 15 in the parallel operation mode are appropriately set as in the first embodiment. In addition, the cooling capacity in the series operation mode can be adjusted appropriately. Furthermore, the cycle configuration of the heat pump cycle 10 can be simplified.

Although it is desirable to integrate the bypass opening / closing valve 42, the check valve 43, and the pressure regulating valve 44 as the integrated valve 4 as in the integrated valve 4 of the present embodiment, the present invention is not limited to this. For example, as shown in FIG. 14, the bypass opening / closing valve 42 and the pressure regulating valve 44 may be integrated as an integrated valve 4, and the check valve 43 may be configured separately from the integrated valve 4. This also applies to embodiments other than the present embodiment.

Further, in the integrated valve 4 of the present embodiment, as shown in FIG. 15, the refrigerant flowing through the first refrigerant passage 18a and the refrigerant flowing through the second refrigerant passage 21a may be opposed to each other. According to this, heat exchange via the body 40 between the refrigerant flowing through the first refrigerant passage 18a and the refrigerant flowing through the second refrigerant passage 21a can be promoted.

(Third embodiment)
Next, a third embodiment will be described. This embodiment demonstrates the example which changed the internal structure of the integrated valve 4 with respect to 2nd Embodiment. In the present embodiment, description of the same or equivalent parts as in the second embodiment will be omitted or simplified.

As shown in FIG. 16, in the integrated valve 4 of this embodiment, one end of the second shaft 443 is connected to the bypass opening / closing valve body 421, and the second opening / closing valve body 421 is displaced to the closed position. The other end side of the shaft 443 comes into contact with the bypass opening / closing valve body 421 and presses the pressure adjusting valve body 441 so that the passage opening degree (passage area) of the second refrigerant passage 21a is enlarged.

In addition, the pressure adjusting valve body 441 of the present embodiment has a recess 441a that supports the other end of the second shaft 443 on the upper surface side, and vibration of the pressure adjusting valve body 441 is generated in the recess 441a. A vibration absorbing member 441b (for example, an O-ring) that suppresses transmission to the second shaft 443 is provided.

Thus, if the second shaft 443 presses the pressure regulating valve body 441 when the bypass opening / closing valve body 421 is displaced to the closed position, the constant pressure maintaining function by the pressure regulating valve body 441 is not exhibited. The function can be stopped.

Other configurations and operations are the same as those in the second embodiment. Therefore, even if the integrated valve 4 having the internal configuration described in the present embodiment is employed, the endothermic amounts of the indoor evaporator 20 and the outdoor heat exchanger 15 in the parallel operation mode as in the first and second embodiments. It is possible to appropriately adjust the cooling capacity in the series operation mode. Furthermore, the cycle configuration of the heat pump cycle 10 can be simplified.

The integrated valve 4 of the first embodiment is the same as the integrated valve 4 of the present embodiment, and the other end of the second shaft 443 is in contact with the pressure adjusting valve body 441 and the one end side is the bypass opening / closing valve body. 421 may be connected.

(Other embodiments)
While the embodiments have been described above, the present disclosure is not limited to the above-described embodiments, and can be appropriately changed within the scope described in the claims. For example, various modifications are possible as follows.

In each of the above-described embodiments, the example in which the heating mode, the cooling mode, and the dehumidifying heating mode are switched in accordance with the operation signal of the operation mode setting switch has been described. For example, the heating mode, the cooling mode, and the dehumidifying heating mode may be switched according to the target blowing temperature TAO, the outside air temperature Tam, and the like.

In each of the above-described embodiments, the control device 100 closes any one of the air passage of the indoor condenser 12 and the heater core 34 and the cold air bypass passage 35 in each operation mode of the heating mode, the cooling mode, and the dehumidifying heating mode. The example of operating the air mix door 36 as described above has been described, but the operation of the air mix door 36 is not limited to this.

For example, the air mix door 36 may open both the air passage of the indoor condenser 12 and the heater core 34 and the cold air bypass passage 35. The temperature of the air blown into the vehicle interior may be adjusted by adjusting the air volume ratio between the air volume that passes through the air passages of the indoor condenser 12 and the heater core 34 and the air volume that passes through the cold air bypass passage 35. Good. Such temperature adjustment is effective in that it is easy to finely adjust the temperature of the air blown into the passenger compartment.

As in each of the above-described embodiments, it is desirable to employ the drive motor 423 that can arbitrarily displace the bypass opening / closing valve element 421 in the range of the closed position and the opening position of the bypass opening / closing valve element 421, but is not limited thereto. The bypass opening / closing valve body 421 can be appropriately adopted as long as it can be displaced to the closed position and the open position.

In each of the above-described embodiments, the example in which the drive motor 423 is used as the drive unit that displaces the bypass opening / closing valve body 421 has been described. However, the present invention is not limited thereto, and the drive unit may be an electromagnetic mechanism such as a solenoid. .

In each of the above-described embodiments, the heater core 34 is arranged inside the indoor air conditioning unit 30. However, when an external heat source such as an engine is insufficient, the heater core 34 is abolished or replaced with an electric heater or the like. It may be.

As in the above-described embodiments, in order to simplify the cycle configuration of the heat pump cycle 10, it is desirable to integrate at least the bypass on-off valve 42 and the pressure regulating valve 44 as the integrated valve 4, but not limited thereto, The bypass opening / closing valve 42 and the pressure adjustment valve 44 may be configured separately.

In each of the above-described embodiments, the example in which the heat pump cycle 10 of the present disclosure is applied to the vehicle air conditioner 1 has been described. However, the present invention is not limited thereto, and may be applied to, for example, a stationary air conditioner.

In each of the above-described embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. The positional relationship is not limited.

Claims

A compressor (11) for compressing and discharging the refrigerant;
A radiator (12) that radiates heat to the blown air that blows the refrigerant discharged from the compressor to the air-conditioning target space;
An outdoor heat exchanger (15) for exchanging heat between the refrigerant flowing out of the radiator and outside air;
An evaporator (20) for evaporating the refrigerant flowing in the cycle and cooling the blown air before passing through the radiator;
A serial operation mode in which the refrigerant flowing out of the radiator flows in the order of the outdoor heat exchanger and the evaporator, and a parallel operation mode in which the refrigerant flowing out of the radiator is flowed to both the outdoor heat exchanger and the evaporator. An operation mode switching unit (100a) for switching;
A pressure adjusting unit (44) for adjusting the pressure of the refrigerant flowing through the evaporator;
The operating state of the pressure adjusting unit is switched between a function exhibiting state that exhibits a constant pressure adjusting function that maintains the pressure of the refrigerant flowing through the evaporator at a predetermined set pressure value, and a function halt state that does not exhibit the constant pressure adjusting function. An operating state switching part (100b),
The operating state switching unit is
Switch the operating state of the pressure adjusting unit to the function exhibiting state during the parallel operation mode,
A heat pump cycle for switching the operating state of the pressure adjusting unit to the function stop state during the series operation mode.
A first throttle section (14) configured to depressurize the refrigerant flowing into the outdoor heat exchanger and change the throttle opening;
A second throttle part (19) configured to depressurize the refrigerant flowing into the evaporator and change the throttle opening; and
The operation mode switching unit is
In the serial operation mode, the refrigerant flowing out of the radiator is made to flow in the order of the first throttle unit, the outdoor heat exchanger, the second throttle unit, the evaporator, the pressure adjusting unit, and the suction side of the compressor. Switch to refrigerant flow path,
In the parallel operation mode, the refrigerant flowing out of the radiator is caused to flow in the order of the first throttle part, the outdoor heat exchanger, and the suction side of the compressor, and at the same time, the refrigerant flowing out of the radiator is allowed to flow into the second throttle The heat pump cycle according to claim 1, wherein the heat pump cycle is switched to a refrigerant flow path that flows in the order of the section, the evaporator, the pressure adjusting section, and the suction side of the compressor.
A radiator (12) that radiates the air discharged from the compressor (11) to the air-conditioning space, a heat radiator (12), an outdoor heat exchanger (15) that exchanges heat between the refrigerant flowing out of the radiator and the outside air, and a cycle A series operation that includes an evaporator (20) that evaporates the refrigerant flowing inside and cools the blown air before passing through the radiator, and flows the refrigerant flowing out of the radiator in the order of the outdoor heat exchanger and the evaporator. A heat pump cycle integrated valve applied to a heat pump cycle that can be switched to a mode and a parallel operation mode in which the refrigerant flowing out of the radiator flows to both the outdoor heat exchanger and the evaporator,
A first refrigerant passage (18a) that guides the refrigerant flowing out of the outdoor heat exchanger to the evaporator side during the series operation mode, and bypasses the outdoor heat exchanger for refrigerant flowing out of the radiator during the parallel operation mode. A bypass passage (41) that leads to the evaporator side, and a body (40) in which a second refrigerant passage (21a) that guides the refrigerant flowing out of the evaporator to the suction side of the compressor is formed,
A bypass opening / closing valve element (421) for opening and closing the bypass passage, housed in the body;
By driving the first operating rod (422) connected to the bypass opening / closing valve element, the bypass opening / closing valve element is displaced to the closed position of the bypass passage in the series operation mode, and in the parallel operation mode. A drive unit (423) for displacing the bypass opening / closing valve element to an open position of the bypass passage;
A pressure regulating valve body (441) for maintaining the pressure of the refrigerant contained in the body and flowing into the second refrigerant passage at a predetermined set pressure value;
When the drive unit displaces the bypass opening / closing valve element to the closed position of the bypass passage, the passage opening degree of the second refrigerant passage is expanded more than when the drive portion is displaced to the open position of the bypass passage. A second actuating rod (443) for displacing the pressure adjusting valve body;
Integrated valve for heat pump cycle.
The second operating rod is connected to at least one of the bypass opening and closing valve body and the pressure adjusting valve body,
The integrated valve for a heat pump cycle according to claim 3, wherein the pressure adjusting valve element is displaced in conjunction with the displacement of the bypass opening / closing valve element.
The bypass passage is joined to the first refrigerant passage on the downstream side of the refrigerant flow with respect to the bypass opening and closing valve body,
In the first refrigerant passage, when the drive unit displaces the bypass opening / closing valve element to the open position of the bypass passage, the refrigerant flowing through the bypass passage passes through the first refrigerant passage to the outdoor side. The integrated valve for a heat pump cycle according to claim 3 or 4, wherein a backflow prevention valve (43) for preventing outflow to the heat exchanger side is arranged.
The body is formed with a through hole (408) for communicating the bypass passage and the second refrigerant passage,
The second operating rod is disposed so as to penetrate the through hole,
Seal parts (408a, 408b) for suppressing the leakage of the refrigerant from the gap formed between the second operating rod and the through hole and absorbing the vibration of the pressure adjusting valve body are disposed in the through hole. The integrated valve for heat pump cycles according to any one of claims 3 to 5.
7. The drive unit according to claim 3, wherein the drive unit is configured to be capable of arbitrarily displacing the bypass opening / closing valve element via the first operating rod in a range of a closed position and an open position of the bypass passage. The integrated valve for heat pump cycles as described in one.
The flow direction of the refrigerant flowing through at least a part of the second refrigerant path in the second refrigerant path is opposite to the flow direction of the refrigerant flowing through at least a part of the first refrigerant path. An integrated valve for a heat pump cycle according to any one of 3 to 7.