WO2018159156A1 - Evaporation pressure regulating valve - Google Patents

Abstract

Provided is an evaporation pressure regulating valve, which is disposed between an evaporator (18) and a compressor (11) in a refrigeration cycle (10), and which regulates a refrigerant evaporation pressure in the evaporator to be equal to or higher than a predetermined reference evaporation pressure. The evaporation pressure regulating valve comprises: a refrigerant inflow channel (42); a valve chest (51); a body (40) in which a refrigerant outflow channel (43) is formed; a valve element (55); an opening degree adjustment chamber (53); an elastic member (61); and a sealing member (71, 72, 73). The valve element includes a large-diameter portion (56) and a small-diameter portion (60). The opening degree adjustment chamber has an insertion hole (48), through which the small-diameter portion is inserted, and has therein reference gas for generating reference pressure. The elastic member is disposed in the opening degree adjustment chamber, and biases the small-diameter portion of the valve element in the closing direction. The sealing member blocks the flow of refrigerant through the insertion hole between the valve chest and the opening degree adjustment chamber.

Description

Evaporation pressure adjustment valve Cross-reference of related applications

This application is based on Japanese Patent Application No. 2017-40013 filed on Mar. 3, 2017, the contents of which are incorporated herein by reference.

This disclosure relates to an evaporation pressure adjusting valve used in a refrigeration cycle.

Conventionally, the evaporation pressure regulating valve is disposed between the evaporator and the compressor in the vapor compression refrigeration cycle, and suppresses frost formation in the evaporator. The evaporating pressure adjusting valve is configured to increase the valve opening (that is, the refrigerant passage area) as the flow rate of the refrigerant flowing through the evaporator increases. ) At a predetermined reference evaporation pressure (reference evaporation temperature) or higher.

Patent Documents 1 and 2 are known as techniques relating to such an evaporation pressure adjusting valve. Patent Document 1 describes a so-called bellows type evaporation pressure adjusting valve. The evaporating pressure adjusting valve of Patent Document 1 includes a valve body that adjusts the opening degree in the refrigerant flow path inside the body, a bellows in which a reference gas is sealed, and a spring disposed inside the bellows. Has been.

On the other hand, Patent Document 2 describes a so-called diaphragm type evaporation pressure regulating valve. The evaporation pressure regulating valve described in Patent Document 2 includes a valve body that adjusts the opening degree in the refrigerant flow path inside the body, a diaphragm that partitions between the cladding tube into which the reference gas is introduced and the refrigerant flow path, And a spring disposed inside the cladding tube.

JP 2015-17774 A Japanese Patent Publication No. 55-51154

In the bellows-type evaporation pressure regulating valve as described in Patent Document 1, the valve body is displaced by a balance between the refrigerant pressure on the evaporator side, the pressure of the reference gas, and the resultant force of the bellows itself and the elastic force of the spring. Then, the opening degree of the evaporation pressure adjusting valve is determined. Here, in Patent Document 1, when the displacement amount of the valve body increases, not only the elastic force of the spring but also the elastic force of the bellows itself and the pressure of the reference gas increase. Therefore, evaporation at the maximum flow rate and the minimum flow rate The difference in the refrigerant evaporation pressure of the vessel became large.

Moreover, in the diaphragm type evaporation pressure regulating valve as in Patent Document 2, atmospheric pressure is used as the reference pressure, and the reference pressure shows a constant value regardless of the displacement of the valve body. For this reason, in patent document 2, if the displacement amount of a valve body increases, only the elastic force of a spring will increase. Therefore, the diaphragm-type evaporation pressure regulating valve described in Patent Document 2 can reduce the difference in the refrigerant evaporation pressure of the evaporator at the maximum flow rate and the minimum flow rate as compared with the case of Patent Document 1.

However, the diaphragm as in Patent Document 2 is made of a rubber material and has refrigerant permeability due to its molecular composition. Furthermore, in this configuration, it is necessary to fold the thin film portion of the diaphragm in order to ensure the amount of displacement of the valve body. As a result, since the permeation area of the refrigerant through the diaphragm is increased, the refrigerant permeation amount through the diaphragm is increased, and the function as an evaporation pressure adjusting valve due to the refrigerant permeation and the surrounding environment are affected.

This disclosure is intended to provide an evaporation pressure adjusting valve that can reduce the difference in the refrigerant evaporation pressure of the evaporator between the maximum flow rate and the minimum flow rate while suppressing refrigerant permeation.

In one aspect of the present disclosure, an evaporation pressure adjusting valve that is disposed between the evaporator and the compressor in the refrigeration cycle and adjusts the refrigerant evaporation pressure in the evaporator to be equal to or higher than a predetermined reference evaporation pressure,
A body with a valve chamber formed inside,
A refrigerant inflow path provided in the body and through which refrigerant flows from the evaporator into the valve chamber;
A refrigerant outflow path provided in the body and through which refrigerant flows out from the valve chamber to the compressor;
A large-diameter portion that is slidable in a predetermined direction in response to the pressure on the refrigerant inflow passage side in the valve chamber, and that has a smaller area than that of the large-diameter portion A valve body including an axial small diameter portion extending in a predetermined direction from the diameter portion;
A reference gas that is arranged adjacent to the valve chamber in a predetermined direction and has an insertion hole that is inserted by a small diameter portion of the valve body and generates a reference pressure that is referred to when determining the opening of the refrigerant flow path. An opening adjustment chamber,
An elastic member disposed inside the opening adjustment chamber and energizing the small diameter portion of the valve body in the closing direction to reduce the opening of the refrigerant flow path;
And a sealing member that blocks the flow of the refrigerant through the insertion hole between the valve chamber and the opening adjustment chamber.

The evaporating pressure adjusting valve is configured in this manner, so that the refrigerant is obtained by the pressure difference between the refrigerant pressure on the refrigerant inflow path applied to the small diameter portion of the valve body and the reference pressure in the opening adjustment chamber, and the elastic force of the elastic member. The refrigerant evaporating pressure in the evaporator can be adjusted by determining the opening degree of the flow path. The small-diameter part of the valve body is formed in a sufficiently smaller area than the large-diameter part, and no other external force is required to determine the opening, so the refrigerant evaporating pressure at the maximum and minimum refrigerant flow rates in the evaporator This difference can be made sufficiently small.

Further, in the evaporating pressure regulating valve, the refrigerant may be transmitted to the outside of the refrigeration cycle through the insertion hole and the small diameter portion. For this reason, according to the evaporation pressure regulating valve, the seal member blocks the flow of the refrigerant through the insertion hole between the valve chamber and the opening degree regulating chamber, thereby suppressing the refrigerant permeation outside the refrigeration cycle. can do.

It is sectional drawing which shows schematic structure of the evaporation pressure control valve which concerns on 1st Embodiment. It is explanatory drawing which shows the structure of the vehicle air conditioner which concerns on 1st Embodiment. It is a graph for comparing the pressure gradient of the evaporation pressure regulating valve which concerns on 1st Embodiment, and a conventional structure. It is sectional drawing which shows schematic structure of the evaporation pressure control valve which concerns on 2nd Embodiment. It is an enlarged view of the opening degree adjustment chamber periphery in 2nd Embodiment. It is sectional drawing which shows schematic structure of the evaporation pressure control valve which concerns on 3rd Embodiment. It is an enlarged view of the opening degree adjustment chamber periphery in 3rd Embodiment.

Hereinafter, embodiments 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)
The evaporation pressure regulating valve 19 according to the first embodiment is used as one of the components in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1. The vehicle air conditioner 1 is mounted on a hybrid vehicle that obtains driving force for vehicle travel from an internal combustion engine and a travel motor. And the refrigerating cycle apparatus 10 fulfill | performs the function which cools or heats the vehicle interior ventilation air ventilated in the vehicle interior which is air-conditioning object space in the vehicle air conditioner 1. FIG.

As shown in FIG. 2, the evaporation pressure regulating valve 19 is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10, and suppresses frost formation in the indoor evaporator 18. Yes.

First, the configuration of the vehicle air conditioner 1 and the refrigeration cycle apparatus 10 including the evaporation pressure adjusting valve 19 will be described with reference to FIG. The refrigeration cycle apparatus 10 according to the first embodiment is configured to be capable of switching between a heating mode refrigerant circuit, a dehumidifying heating mode refrigerant circuit, and a cooling mode refrigerant circuit.

Here, in the vehicle air conditioner 1, the heating mode is an operation mode in which the blown air is heated and blown out into the passenger compartment. The dehumidifying and heating mode is an operation mode in which the blown air that has been cooled and dehumidified is reheated and blown out into the passenger compartment. The cooling mode is an operation mode in which the blown air is cooled and blown out into the passenger compartment.

In FIG. 2, the refrigerant flow in the refrigerant circuit in the heating mode is indicated by black arrows, and the refrigerant flow in the refrigerant circuit in the dehumidifying heating mode is indicated by hatched arrows. Further, the flow of the refrigerant in the cooling mode refrigerant circuit is indicated by white arrows.

The refrigeration cycle apparatus 10 employs an HFC refrigerant (specifically, R134a) as the refrigerant, and constitutes a vapor compression subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. is doing. Of course, an HFO refrigerant (for example, R1234yf), a natural refrigerant (for example, R744), or the like may be employed as the refrigerant. Furthermore, the refrigerating machine oil for lubricating the compressor 11 is mixed in the refrigerant, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

As shown in FIG. 2, the refrigeration cycle apparatus 10 includes a compressor 11, a first expansion valve 15a, a second expansion valve 15b, an outdoor heat exchanger 16, a check valve 17, an indoor evaporator 18, and an evaporation pressure adjusting valve 19. And an accumulator 20, a first on-off valve 21, and a second on-off valve 22.

The compressor 11 sucks the refrigerant in the refrigeration cycle apparatus 10 and compresses and discharges the refrigerant. The compressor 11 is disposed in the vehicle bonnet. The compressor 11 is configured as an electric compressor that drives a fixed capacity type compression mechanism with a fixed discharge capacity by an electric motor. The compressor 11 functions as a compressor in the present disclosure.

As the compression mechanism of the compressor 11, various compression mechanisms such as a scroll-type compression mechanism and a vane-type compression mechanism can be employed. The operation (rotation speed) of the electric motor constituting the compressor 11 is controlled by a control signal output from an air conditioning control device (not shown). As this electric motor, either an AC motor or a DC motor may be adopted.

The refrigerant inlet side of the indoor condenser 12 is connected to the discharge port of the compressor 11. The indoor condenser 12 functions as a heat exchanger for heating in the heating mode and the dehumidifying heating mode. That is, in the heating mode and the dehumidifying heating mode, the indoor condenser 12 exchanges heat between the high-temperature and high-pressure discharged refrigerant discharged from the compressor 11 and the blown air that has passed through the indoor evaporator 18 to be described later. Heat. The indoor condenser 12 is arrange | positioned in the casing 31 of the indoor air conditioning unit 30 mentioned later.

The refrigerant outlet of the indoor condenser 12 is connected to one inflow / outlet side of the first three-way joint 13a. A three-way joint such as the first three-way joint 13a functions as a branching part or a joining part in the refrigeration cycle apparatus 10.

For example, in the first three-way joint 13a in the dehumidifying and heating mode, one of the three inlets and outlets is used as an inlet and the remaining two are used as outlets. Therefore, the first three-way joint 13a in the dehumidifying and heating mode functions as a branching portion that branches the flow of the refrigerant flowing in from one inflow port and outflows from the two outflow ports. These three-way joints may be formed by joining a plurality of pipes, or may be formed by providing a plurality of refrigerant passages in a metal block or a resin block.

Furthermore, the refrigeration cycle apparatus 10 includes a second three-way joint 13b to a fourth three-way joint 13d, as will be described later. The basic configuration of the second three-way joint 13b to the fourth three-way joint 13d is the same as that of the first three-way joint 13a. For example, in the fourth three-way joint 13d in the dehumidifying and heating mode, two of the three inlets and outlets are used as inlets, and the remaining one is used as an outlet. Accordingly, the fourth three-way joint 13d in the dehumidifying and heating mode functions as a joining portion that joins the refrigerant that has flowed in from the two inlets and flows out from the one outlet.

The first refrigerant passage 14a is connected to another inflow / outlet of the first three-way joint 13a. The first refrigerant passage 14 a guides the refrigerant flowing out from the indoor condenser 12 to the refrigerant inlet side of the outdoor heat exchanger 16.

The second refrigerant passage 14b is connected to still another inflow / outlet of the first three-way joint 13a. The second refrigerant passage 14b allows the refrigerant flowing out from the indoor condenser 12 to flow into the inlet side of the second expansion valve 15b (specifically, one of the third three-way joints 13c) disposed in the third refrigerant passage 14c described later. Inlet / outlet).

A first expansion valve 15a is disposed in the first refrigerant passage 14a. The first expansion valve 15a decompresses the refrigerant that has flowed out of the indoor condenser 12 during the heating mode and the dehumidifying heating mode. The first expansion valve 15a functions as a pressure reducing device. The first expansion valve 15a is a variable throttle mechanism having a valve body configured to be able to change the throttle opening degree and an electric actuator composed of a stepping motor that changes the throttle opening degree of the valve body.

Furthermore, the first expansion valve 15a is configured as a variable throttle mechanism with a fully open function that functions as a simple refrigerant passage with almost no refrigerant decompression effect by fully opening the throttle opening. The operation of the first expansion valve 15a is controlled by a control signal (control pulse) output from an air conditioning control device (not shown).

The refrigerant inlet side of the outdoor heat exchanger 16 is connected to the outlet side of the first expansion valve 15a, and is arranged on the vehicle front side in the vehicle bonnet. The outdoor heat exchanger 16 exchanges heat between the refrigerant that has flowed out of the first expansion valve 15a and the outside air (outside air) blown from a blower fan (not shown). The blower fan is an electric blower whose number of rotations (blowing capacity) is controlled by a control voltage output from an air conditioning control device (not shown).

Specifically, the outdoor heat exchanger 16 functions as a heat absorber that absorbs heat from the outside air in the heating mode. In the cooling mode and the dehumidifying and heating mode, the outdoor heat exchanger 16 functions as a radiator that radiates heat to the outside air.

One inflow / outlet of the second three-way joint 13b is connected to the refrigerant outlet side of the outdoor heat exchanger 16. A third refrigerant passage 14c is connected to another inflow / outlet of the second three-way joint 13b. The third refrigerant passage 14 c guides the refrigerant that has flowed out of the outdoor heat exchanger 16 to the refrigerant inlet side of the indoor evaporator 18.

Further, a fourth refrigerant passage 14d is connected to another inflow / outlet of the second three-way joint 13b. The fourth refrigerant passage 14d guides the refrigerant that has flowed out of the outdoor heat exchanger 16 to the inlet side of the accumulator 20, which will be described later (specifically, one inlet / outlet of the fourth three-way joint 13d).

In the third refrigerant passage 14c, a check valve 17, a third three-way joint 13c, and a second expansion valve 15b are arranged in this order with respect to the refrigerant flow. The check valve 17 only allows the refrigerant to flow from the second three-way joint 13b side to the indoor evaporator 18 side. The second refrigerant passage 14b described above is connected to the third three-way joint 13c.

The second expansion valve 15b depressurizes the refrigerant that flows out of the outdoor heat exchanger 16 and flows into the indoor evaporator 18. That is, the second expansion valve 15b functions as a pressure reducing device. The basic configuration of the second expansion valve 15b is the same as that of the first expansion valve 15a. Further, the second expansion valve 15b is constituted by a variable throttle mechanism with a fully-closed function that closes the refrigerant passage when the throttle opening is fully closed.

Therefore, in the refrigeration cycle apparatus 10 according to the first embodiment, the refrigerant circuit can be switched by fully closing the second expansion valve 15b and closing the third refrigerant passage 14c. In other words, the second expansion valve 15b functions as a refrigerant decompression device and also has a function as a refrigerant circuit switching device that switches a refrigerant circuit of the refrigerant circulating in the cycle.

The indoor evaporator 18 functions as a cooling heat exchanger in the cooling mode and the dehumidifying heating mode. That is, the indoor evaporator 18 exchanges heat between the refrigerant flowing out of the second expansion valve 15b and the blown air before passing through the indoor condenser 12 in the cooling mode and the dehumidifying heating mode, and functions as an evaporator in the present disclosure. . In the indoor evaporator 18, the blown air is cooled by evaporating the refrigerant decompressed by the second expansion valve 15 b and exerting an endothermic action. The indoor evaporator 18 is arranged in the casing 31 of the indoor air conditioning unit 30 on the upstream side of the air flow of the indoor condenser 12.

The inlet side of the evaporation pressure adjusting valve 19 is connected to the refrigerant outlet of the indoor evaporator 18. The evaporation pressure adjusting valve 19 has a function of adjusting the refrigerant evaporation pressure (that is, the low-pressure side refrigerant pressure) in the indoor evaporator 18 to be equal to or higher than the frosting suppression pressure in order to suppress frost formation (frost) of the indoor evaporator 18. Fulfill. In other words, the evaporation pressure adjusting valve 19 functions to adjust the refrigerant evaporation temperature in the indoor evaporator 18 to a predetermined frosting suppression temperature or higher. The specific configuration of the evaporation pressure adjusting valve 19 will be described in detail later with reference to the drawings.

As shown in FIG. 2, a fourth three-way joint 13 d is connected to the outlet side of the evaporation pressure adjusting valve 19. As described above, the fourth refrigerant passage 14d is connected to the other inlet / outlet of the fourth three-way joint 13d. And the inlet side of the accumulator 20 is connected to another inflow / outlet of the fourth three-way joint 13d.

The accumulator 20 is a gas-liquid separator that separates the gas-liquid of the refrigerant that has flowed into the accumulator 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 20. Therefore, the accumulator 20 functions to prevent liquid phase refrigerant from being sucked into the compressor 11 and prevent liquid compression in the compressor 11.

Further, the first on-off valve 21 is disposed in the fourth refrigerant passage 14d that connects the second three-way joint 13b and the fourth three-way joint 13d. The first on-off valve 21 is constituted by an electromagnetic valve. The first on-off valve 21 functions as a refrigerant circuit switching device that switches the refrigerant circuit by opening and closing the fourth refrigerant passage 14d. The operation of the first on-off valve 21 is controlled by a control signal output from an air conditioning control device (not shown).

Similarly, a second on-off valve 22 is disposed in the second refrigerant passage 14b connecting the first three-way joint 13a and the third three-way joint 13c. Similar to the first on-off valve 21, the second on-off valve 22 is configured by an electromagnetic valve. The second on-off valve 22 functions as a refrigerant circuit switching device that switches the refrigerant circuit by opening and closing the second refrigerant passage 14b.

Next, the indoor air conditioning unit 30 that constitutes the vehicle air conditioner 1 together with the refrigeration cycle apparatus 10 will be described. The indoor air conditioning unit 30 blows out the blown air whose temperature has been adjusted by the refrigeration cycle apparatus 10 into the vehicle interior. The indoor air conditioning unit 30 is disposed inside the instrument panel (instrument panel) at the forefront of the vehicle interior.

As shown in FIG. 2, the indoor air conditioning unit 30 houses a blower 32, an indoor evaporator 18, an indoor condenser 12, and the like in a casing 31 that forms an outer shell thereof. The casing 31 forms an air passage for blown air that is blown into the vehicle interior. The casing 31 is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent in strength.

The inside / outside air switching device 33 is arranged on the most upstream side of the blast air flow in the casing 31. The inside / outside air switching device 33 switches and introduces inside air (vehicle compartment air) and outside air (vehicle compartment outside air) into the casing 31.

Specifically, the inside / outside air switching device 33 continuously adjusts the opening area of the inside air introduction port for introducing the inside air into the casing 31 and the outside air introduction port for introducing the outside air by the inside / outside air switching door, The air volume ratio between the air volume and the outside air volume can be continuously changed. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The operation of the electric actuator is controlled by a control signal output from an air conditioning control device (not shown).

A blower 32 is disposed on the downstream side of the blown air flow of the inside / outside air switching device 33. The blower 32 blows air sucked through the inside / outside air switching device 33 toward the vehicle interior. The blower 32 is an electric blower that drives a centrifugal multiblade fan (sirocco fan) with an electric motor. The number of rotations of the centrifugal multiblade fan in the blower 32 (air flow rate) is controlled by a control voltage output from an air conditioning control device (not shown).

On the downstream side of the blower air flow of the blower 32, the indoor evaporator 18 and the indoor condenser 12 are arranged in this order with respect to the blown air flow. In other words, the indoor evaporator 18 is disposed on the upstream side of the blown air flow with respect to the indoor condenser 12.

Further, a cold air bypass passage 35 is formed in the casing 31. The cold air bypass passage 35 is a passage for allowing the blown air that has passed through the indoor evaporator 18 to flow downstream by bypassing the indoor condenser 12.

An air mix door 34 is disposed on the downstream side of the blower air flow of the indoor evaporator 18 and on the upstream side of the blower air flow of the indoor condenser 12. The air mix door 34 is used when adjusting the ratio of the amount of air passing through the indoor condenser 12 in the blown air after passing through the indoor evaporator 18. Therefore, the vehicle air conditioner 1 sets the cold air bypass passage 35 to a fully open position, and fully closes the flow path of the blown air toward the indoor condenser 12 by the air mix door 34, whereby the heat exchange amount in the indoor condenser 12 is reached. Can be minimized.

In addition, a mixing space is provided on the downstream side of the blower air flow of the indoor condenser 12. In the mixing space, the blown air heated by the indoor condenser 12 and the blown air that has passed through the cold air bypass passage 35 and is not heated by the indoor condenser 12 are mixed. Further, a plurality of opening holes are arranged in the most downstream portion of the blown air flow of the casing 31. The blown air (air conditioned air) mixed in the mixing space is blown out into the vehicle interior, which is the air conditioning target space, through these opening holes.

These opening holes are specifically provided with a face opening hole, a foot opening hole, and a defroster opening hole (all not shown). The face opening hole is an opening hole for blowing air conditioned air toward the upper body of the passenger in the passenger compartment. The foot opening hole is an opening hole for blowing air-conditioned air toward the passenger's feet. The defroster opening hole is an opening hole for blowing conditioned air toward the inner side surface of the vehicle front window glass.

Further, the air flow downstream of the face opening hole, the foot opening hole, and the defroster opening hole is respectively connected to the face air outlet, the foot air outlet, and the defroster air outlet ( Neither is shown). Therefore, the air mix door 34 adjusts the air volume ratio between the air volume that passes through the indoor condenser 12 and the air volume that passes through the cold air bypass passage 35, thereby adjusting the temperature of the conditioned air mixed in the mixing space. The temperature of the conditioned air blown from each outlet into the passenger compartment is adjusted.

That is, the air mix door 34 functions as a temperature adjusting unit that adjusts the temperature of the conditioned air blown into the vehicle interior. The air mix door 34 is driven by an electric actuator for driving the air mix door. The operation of the electric actuator is controlled by a control signal output from an air conditioning control device (not shown).

Further, on the upstream side of the air flow of the face opening hole, foot opening hole, and defroster opening hole, a face door for adjusting the opening area of the face opening hole, a foot door for adjusting the opening area of the foot opening hole, and a defroster opening, respectively. A defroster door (both not shown) for adjusting the opening area of the hole is disposed.

These face doors, foot doors, and defroster doors constitute an outlet mode switching door that switches the outlet mode. The face door, the foot door, and the defroster door are connected to an electric actuator for driving the air outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is also controlled by a control signal output from an air conditioning control device (not shown).

Specific examples of the outlet mode switched by the outlet mode switching door include a face mode, a bi-level mode, and a foot mode.

The face mode is a blowout mode in which the face blowout is fully opened and air is blown out from the face blowout toward the upper body of the passengers in the passenger compartment. The bi-level mode is an air outlet mode in which both the face air outlet and the foot air outlet are opened and air is blown toward the upper body and the feet of the passengers in the passenger compartment. The foot mode is an air outlet mode in which the foot air outlet is fully opened and blown air is blown from the foot air outlet toward the feet of the passengers in the passenger compartment.

Further, the defroster mode can be set by manually operating the blow mode switching switch provided on the operation panel. The defroster mode is a blowout port mode in which the defroster blowout port is fully opened and air is blown from the defroster blowout port to the inner surface of the vehicle front window glass.

As described above, the vehicle air conditioner 1 can switch the operation mode to the cooling operation, the heating operation, and the dehumidifying heating operation. The specific operation and control for each operation mode is described in, for example, Japanese Patent Application Laid-Open No. 2012-225637. Therefore, the description about these points is omitted.

Next, a specific configuration of the evaporation pressure adjusting valve 19 disposed in the vehicle air conditioner 1 and the refrigeration cycle apparatus 10 will be described in detail with reference to the drawings.

As described above, the evaporation pressure regulating valve 19 according to the first embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10. The evaporating pressure adjusting valve 19 is constituted by a pure mechanical mechanism, and adjusts so that the refrigerant evaporating pressure P1 in the indoor evaporator 18 becomes equal to or higher than a predetermined reference evaporating pressure (that is, frosting suppression pressure APe). Fulfills the function.

Specifically, the evaporation pressure adjusting valve 19 has a body 40 configured by combining a plurality of metal members made of aluminum alloy or the like, and a valve on a refrigerant passage formed inside the body 40. The valve body 55 is slidably accommodated in the chamber 51.

The body 40 forms an outer shell of the evaporation pressure adjusting valve 19 and includes a main body 41, a cylinder 45, and a cover 52. As shown in FIG. 1, the valve chamber 51 is formed between the main body portion 41 and the cylinder portion 45, and the opening adjustment chamber 53 is formed between the cylinder portion 45 and the cover 52. Accordingly, the valve chamber 51 and the opening adjustment chamber 53 are formed inside the body 40.

As shown in FIG. 1, the main body 41 has a refrigerant inflow path 42, a refrigerant outflow path 43, and a connection space 44 formed inside the main body 41. The refrigerant inflow path 42 is formed so as to extend linearly from one side surface of the main body 41 and is a flow path into which the refrigerant from the indoor evaporator 18 flows.

The refrigerant outflow passage 43 is formed so as to extend linearly in a direction substantially orthogonal to the refrigerant inflow passage 42, and is a passage through which the refrigerant flows out toward the suction port side of the compressor 11 via the accumulator 20. is there.

The connection space 44 is formed so as to be connected to both the refrigerant inflow path 42 and the refrigerant outflow path 43 inside the main body 41. Accordingly, the refrigerant flowing in from the refrigerant inflow passage 42 flows out from the refrigerant outflow passage 43 toward the compressor 11 through the connection space 44. The connection space 44 is formed by opening a surface facing the side surface of the main body 41 where the refrigerant inflow passage 42 is formed.

The cylinder part 45 is disposed in the connection space part 44 from the opposite side of the main body part 41 from the surface where the refrigerant inflow passage 42 is formed, and has a cylindrical part 46 formed in a substantially cylindrical shape. The cylinder portion 45 is disposed in the connection space portion 44 by being crimped so that the tip end portion of the cylindrical portion 46 is in close contact with the inner wall surface on the refrigerant inflow path 42 side.

A plurality of communication holes 47 are formed in the tubular portion 46. Each communication hole 47 opens so as to penetrate the tubular portion 46 in the thickness direction, and communicates the internal space of the tubular portion 46 with the space outside the tubular portion 46 in the connection space portion 44. Yes.

Therefore, the refrigerant that has flowed into the internal space of the cylindrical portion 46 from the refrigerant inflow path 42 flows out to the refrigerant outflow path 43 through the plurality of communication holes 47. In the evaporation pressure adjusting valve 19, a cylindrical space formed inside the cylindrical portion 46 of the cylinder portion 45 functions as the valve chamber 51 in the connection space portion 44.

A concave portion 49 is formed on the cylinder portion 45 on the opposite side to the cylindrical portion 46. The concave portion 49 is recessed toward the refrigerant inflow path 42 side, and forms a cylindrical space inside thereof. The concave portion 49 is formed coaxially with the central axis of the cylindrical portion 46 having a cylindrical shape.

Further, an insertion hole 48 is formed in the recess 49. The insertion hole 48 connects the space inside the cylindrical portion 46 and the space inside the concave portion 49 in the cylinder portion 45, and extends linearly along the central axis of the cylindrical portion 46 and the concave portion 49. Is formed. As shown in FIG. 1, a small diameter portion 60 of a valve body 55 described later is inserted through the insertion hole 48.

A packing 50 is disposed on the outer peripheral surface of the cylinder portion 45. The packing 50 is located between the inner wall surface of the connection space portion 44 of the main body portion 41 and the outer peripheral surface of the cylinder portion 45 and prevents leakage of the refrigerant.

As shown in FIG. 1, the valve chamber 51 of the evaporation pressure regulating valve 19 is formed by an internal space in the cylindrical portion 46 of the cylinder portion 45 in the connection space portion 44 of the main body portion 41. That is, the valve chamber 51 is formed in the body 40 by the main body portion 41 and the cylinder portion 45.

The cover 52 is disposed so as to cover the concave portion 49 of the cylinder portion 45. In the evaporation pressure adjusting valve 19, an opening adjustment chamber 53 for adjusting the opening of the evaporation pressure adjusting valve 19 is formed by arranging a cover 52 so as to cover the concave portion 49 of the cylinder portion 45.

Since the opening adjusting chamber 53 includes a part of the recess 49, the opening adjusting chamber 53 communicates with the valve chamber 51 through the insertion hole 48. In other words, the opening adjustment chamber 53 is adjacent to the valve chamber 51 through the cylinder portion 45 and has the insertion hole 48.

The cover 52 is formed with an air introduction hole 54 and communicates the outside of the evaporating pressure adjusting valve 19 and the inside of the opening adjusting chamber 53. Therefore, the atmosphere introduction hole 54 functions to introduce the atmosphere outside the evaporation pressure adjustment valve 19 into the opening degree adjustment chamber 53.

The atmosphere introduced into the opening adjustment chamber 53 functions as a reference gas for determining the opening of the refrigerant flow path in the evaporation pressure adjustment valve 19 and generates a reference pressure in the opening adjustment chamber 53. Therefore, the reference pressure in the evaporation pressure adjusting valve 19 is atmospheric pressure.

In the valve chamber 51, the valve body 55 receives the refrigerant pressure on the refrigerant inflow path 42 side (that is, the refrigerant evaporation pressure P <b> 1 of the indoor evaporator 18), and slides in the direction along the central axis of the cylindrical portion 46 and the like. It is arranged to be movable. As shown in FIG. 1, the valve body 55 has a large-diameter portion 56 capable of closing the plurality of communication holes 47 in the tubular portion 46, and an axial small-diameter portion 60 extending from the large-diameter portion 56. It is formed in a so-called spool valve shape.

The large-diameter portion 56 is formed of a bottomed cylindrical (cup-shaped) metal member and has a peripheral wall portion 57. The peripheral wall portion 57 is disposed along the inner wall surface of the tubular portion 46 inside the valve chamber 51. The outer diameter dimension of the large-diameter portion 56 has a dimensional relationship of the clearance fit with respect to the inner diameter dimension of the cylindrical portion 46 in the cylinder portion 45.

Therefore, in the valve chamber 51, when the large diameter portion 56 of the valve body 55 is located closest to the refrigerant inflow passage 42 side, the opening area of each communication hole 47 of the cylindrical portion 46 is reduced by the peripheral wall portion 57, The flow of refrigerant from the refrigerant inflow path 42 toward the refrigerant outflow path 43 can be reduced.

Further, in the valve chamber 51, when the large diameter portion 56 of the valve body 55 is located closest to the opening adjustment chamber 53 side, the opening area of each communication hole 47 of the cylindrical portion 46 is increased by the peripheral wall portion 57. Thus, the refrigerant flow from the refrigerant inflow path 42 to the refrigerant outflow path 43 can be increased. That is, the evaporation pressure adjusting valve 19 can adjust the opening degree of the refrigerant flow path by sliding the valve body 55 in the valve chamber 51 in the direction along the central axis of the cylindrical portion 46 and the like. it can.

A pressure equalizing hole 58 is formed in the large-diameter portion 56, and the inside of the large-diameter portion 56 formed in a bottomed cylindrical shape and other portions in the valve chamber 51 (that is, the opening adjustment chamber 53). Side space). The pressure equalizing hole 58 makes the pressure of the refrigerant in the valve chamber 51 uniform. An oil return hole 59 is formed in the peripheral wall portion 57 corresponding to the refrigerant outflow passage 43 side. A part of the refrigerating machine oil contained in the refrigerant is returned to the upstream side of the refrigerant flow through the oil return hole 59.

The small diameter portion 60 is formed in a shaft shape extending from the bottom surface portion of the bottomed cylindrical large diameter portion 56 toward the opening adjustment chamber 53 side. The small-diameter portion 60 is formed in a columnar shape extending along the central axis of the cylindrical portion 46 and the like, and is disposed through the insertion hole 48.

The outer diameter dimension of the small-diameter portion 60 has a dimensional relationship with the clearance fit with respect to the inner diameter dimension of the insertion hole 48. Regarding the cross section perpendicular to the central axis of the small diameter portion 60 or the like, the cross sectional area of the small diameter portion 60 is formed smaller than the cross sectional area of the large diameter portion 56 (that is, the cross sectional area corresponding to the bottom of the bottomed cylindrical shape).

An O-ring 71 is disposed on the outer peripheral surface of the small diameter portion 60. The O-ring 71 is formed of nitrile rubber, ethylene propylene rubber, or the like, and is disposed so as to block between the outer peripheral surface of the small diameter portion 60 and the inner wall surface of the insertion hole 48. Therefore, the O-ring 71 can block the flow of the refrigerant from the valve chamber 51 through the insertion hole 48, and can suppress the leakage of the refrigerant from the valve chamber 51 to the opening degree adjustment chamber 53.

Further, the O-ring 71 is disposed between the outer peripheral surface of the small diameter portion 60 and the inner wall surface of the insertion hole 48 so as to come into contact with the refrigerant. Therefore, according to the evaporation pressure adjusting valve 19, the refrigerant permeation area in the O-ring 71 can be sufficiently reduced, and the refrigerant permeation amount, which is a problem specific to rubber, can be suppressed to a low level. That is, the O-ring 71 functions as a seal member in the present disclosure.

Further, a coil spring 61 is disposed inside the opening adjustment chamber 53. The coil spring 61 is a cylindrical coil spring extending in the displacement direction of the valve body 55 and is made of stainless steel.

One end of the coil spring 61 is attached to the tip of a small diameter portion 60 that is inserted through the insertion hole 48 and protrudes into the opening adjustment chamber 53. On the other hand, the other end of the coil spring 61 is attached to the tip of an adjustment screw 62 disposed at a position facing the insertion hole 48 in the opening adjustment chamber 53.

Therefore, the coil spring 61 applies a load that biases the valve body 55 in the valve closing direction (that is, the direction in which the valve body 55 is displaced toward the refrigerant inflow path 42), and functions as an elastic member in the present disclosure. Note that the load by which the coil spring 61 urges the valve body 55 can be adjusted by the adjusting screw 62 including the initial load.

Next, the operation of the evaporation pressure adjusting valve 19 configured as described above will be described with reference to the drawings. As shown in FIG. 1, in the valve chamber 51, the valve body 55 is displaced in the closing direction corresponding to one side in the axial direction (that is, the refrigerant inflow passage 42 side) and the tip of the peripheral wall portion 57 is brought to the inner wall surface of the valve chamber 51. In the contact state, the communication hole 47 is closed by the peripheral wall of the valve body 55. Therefore, in this case, the communication between the refrigerant inflow path 42 and the refrigerant outflow path 43 is blocked.

From the state shown in FIG. 1, when the valve body 55 is displaced in the opening direction corresponding to the other side in the axial direction (that is, the opening adjustment chamber 53 side) and the displacement amount L increases, the communication hole 47 becomes the peripheral wall portion of the valve body 55. It will be exposed from 57. Thereby, in the evaporating pressure adjusting valve 19, the refrigerant inflow path 42 side and the refrigerant outflow path 43 side communicate with each other through the communication hole 47, and the refrigerant flows from the refrigerant inflow path 42 side to the refrigerant outflow path 43 side.

Then, as the displacement amount L of the valve body 55 inside the valve chamber 51 increases, the area of the portion exposed from the peripheral wall portion 57 in the communication hole 47 increases. In the evaporation pressure adjusting valve 19 according to the first embodiment, the valve body 55 is displaced in the valve chamber 51, thereby changing the refrigerant passage area in the evaporation pressure adjusting valve 19 and flowing through the indoor evaporator 18. The refrigerant flow rate and the refrigerant evaporation pressure P1 are adjusted.

Here, the displacement of the valve body 55 in the valve chamber 51 of the evaporation pressure adjusting valve 19 is determined by the force acting on the valve body 55. In the evaporation pressure regulating valve 19, the valve body 55 includes a refrigerant pressure on the refrigerant inflow path 42 side (that is, a refrigerant evaporation pressure P <b> 1 in the indoor evaporator 18) and a refrigerant pressure on the refrigerant outflow path 43 side (that is, the compressor 11). The suction side refrigerant pressure), the load by the coil spring 61, and the pressure of the reference gas in the opening adjustment chamber 53 (ie, atmospheric pressure). Among these, the refrigerant pressure on the refrigerant outflow passage 43 side acts in a direction orthogonal to the axial direction of the valve body 55 and therefore does not contribute to the displacement of the valve body 55 in the axial direction.

That is, in the evaporation pressure adjusting valve 19 according to the first embodiment, the valve body 55 is displaced to a position where these loads acting in the axial direction with respect to the valve body 55 are balanced, and the refrigerant passage in the evaporation pressure adjusting valve 19 The area is adjusted. More specifically, the balance of the load that the valve body 55 receives in the axial direction can be expressed by the following formula F1.
P1 × As = Ks × L + F0 + P0 × As (F1)
Here, P1 is the refrigerant pressure on the refrigerant inflow path 42 side (that is, the refrigerant evaporation pressure P1 in the indoor evaporator 18), P0 is the pressure of the reference gas (that is, atmospheric pressure) in the opening adjustment chamber 53, and As. Is a pressure receiving area of the small diameter portion 60 of the valve body 55, Ks is a spring constant of the coil spring 61, L is a displacement amount of the valve body 55, and F0 is an initial load of the coil spring 61 adjusted by the adjusting screw 62.

By transforming the formula F1, it can be expressed as the following formula F2.
P1 = Ks / As × L + F0 / As + P0 (F2)
According to this formula F2, it can be seen that the refrigerant pressure on the refrigerant inflow path 42 side (that is, the refrigerant evaporation pressure P1) increases as the displacement amount L increases. Further, as described above, as the displacement amount L increases, the refrigerant passage area in the evaporation pressure adjusting valve 19 increases, so the flow rate of refrigerant flowing through the indoor evaporator 18 also increases.

Therefore, the evaporating pressure adjusting valve 19 according to the first embodiment is configured so that the refrigerant pressure on the refrigerant inflow path 42 side increases as the refrigerant flow rate flowing through the indoor evaporator 18 (the refrigerant flow rate flowing through the evaporating pressure adjusting valve 19) increases. In other words, the refrigerant evaporating pressure P1 is increased. That is, the evaporation pressure adjusting valve 19 increases the displacement amount L of the valve body 55 in proportion to the increase in the refrigerant pressure on the refrigerant inflow passage 42 side, and adjusts the evaporation pressure as the refrigerant pressure in the refrigerant inflow passage 42 increases. The refrigerant passage area in the valve 19 is increased.

In the valve body 55 of the evaporation pressure adjusting valve 19, the pressure receiving area of the small diameter portion 60 can be within a range that does not hinder the pressure control in the evaporation pressure adjusting valve 19 with respect to the pressure receiving area of the large diameter portion 56. It is set as small as possible. Specifically, the pressure receiving area of the small diameter portion 60 is set to about 0.15 to 0.2 times the pressure receiving area of the large diameter portion 56. By setting in this way, the load by the coil spring 61 can be made smaller than before while realizing stable pressure control by the evaporation pressure regulating valve 19.

Further, in the evaporation pressure regulating valve 19, the pressure receiving area of the large diameter portion 56 that receives the refrigerant pressure on the refrigerant inflow path 42 side is set to be larger than 1.3 times the flow area of the refrigerant inflow path 42. By setting in this way, the evaporation pressure adjusting valve 19 can reduce the displacement amount L of the valve body 55 and suppress the wear of the O-ring 71 due to the displacement of the valve body 55.

Subsequently, a comparative example of the control characteristic of the refrigerant evaporation pressure P1 in the evaporation pressure adjusting valve 19 configured as described above and the control characteristic of another type of evaporation pressure adjusting valve will be described with reference to FIG.

In addition, in the graph shown in FIG. 3, P1 has shown the relationship between the refrigerant | coolant evaporation pressure P1 and the refrigerant | coolant flow volume in the evaporation pressure regulating valve 19 which concerns on 1st Embodiment. Pa indicates the relationship between the refrigerant evaporation pressure and the refrigerant flow rate by the bellows type evaporation pressure adjustment valve, and Pb indicates the relationship between the refrigerant evaporation pressure and the refrigerant flow rate by the diaphragm type evaporation pressure adjustment valve.

3 indicates the refrigerant evaporation pressure when the refrigerant evaporation temperature in the evaporator is 0 ° C. at the minimum flow rate. That is, the frosting suppression pressure APe corresponds to the reference evaporation pressure in the present disclosure.

First, a bellows type evaporation pressure adjusting valve in this comparative example includes a valve body that adjusts the opening degree in the refrigerant flow path inside the body, a bellows in which a reference gas is sealed, and a spring disposed inside the bellows. For example, it is assumed that it has substantially the same configuration as the evaporation pressure adjusting valve described in Japanese Patent Application Laid-Open No. 2015-17764.

In the bellows-type evaporation pressure regulating valve, the valve body is formed by a balance between the refrigerant pressure on the inlet path side from the evaporator side, the pressure of the reference gas, the elastic force of the bellows itself, and the elastic force of the spring. Displacement is performed, and the opening degree of the evaporation pressure adjusting valve is determined. The balance of the load on the valve body of the bellows type evaporation pressure regulating valve is expressed by the following formula F3 when the pressure receiving area of the valve body is equal to the pressure receiving area of the bellows.
P1 × Av = Ksa × L + Kbw × L + F0 + Fr (F3)
Here, P1 is the refrigerant pressure on the inflow path side, Av is the pressure receiving area of the valve body, Ksa is the spring constant of the spring, Kbw is the spring constant of the bellows itself, L is the amount of displacement of the valve body, F0 is the initial value of the spring, etc. The load Fr is a load due to the pressure of the reference gas enclosed in the bellows.

By transforming the formula F3, it can be expressed as the following formula F4.
P1 = (Ksa + Kbw) / Av × L + F0 / Av + Fr / Av (F4)
According to Formula F4, in the bellows-type evaporation pressure adjusting valve, the refrigerant pressure on the inflow path side increases as the displacement amount L increases.

Here, regarding the formula F2 and the formula F4, when focusing on the coefficient (that is, the pressure gradient) with respect to the displacement L, the pressure gradient of the bellows type evaporation pressure regulating valve is influenced by the combined spring constant of the spring and the bellows itself. Since the pressure receiving area of the small-diameter portion 60 in the evaporation pressure regulating valve 19 is sufficiently small with respect to the pressure receiving area of the valve body, the difference between the refrigerant evaporation pressure of the evaporator at the maximum flow rate and the minimum flow rate becomes large. End up. That is, as shown in FIG. 3, the pressure gradient of the bellows type evaporation pressure adjusting valve is larger than the pressure gradient of the evaporation pressure adjusting valve 19.

Further, in the case of a bellows type evaporation pressure adjusting valve, the reference gas is sealed inside the bellows. As the displacement amount of the bellows increases, the volume inside the bellows decreases, so the pressure of the reference gas increases with the displacement of the valve body. That is, also from this point, the pressure gradient of the bellows type evaporation pressure adjusting valve is larger than that of the evaporation pressure adjusting valve 19.

Next, the Bellofram type evaporation pressure regulating valve in this comparative example will be described. The bellophram-type evaporation pressure adjusting valve includes a valve body that adjusts an opening degree in a refrigerant flow path inside a body, a diaphragm that partitions between a cladding pipe into which a reference gas is introduced and the refrigerant flow path, and the cladding pipe For example, and has substantially the same configuration as the evaporation pressure adjusting valve described in Japanese Patent Publication No. 55-51154.

In the diaphragm type evaporation pressure regulating valve, the valve body is displaced by a balance between the refrigerant pressure on the inflow passage side from the evaporator side, the pressure of the reference gas introduced into the cladding tube, and the elastic force of the spring, The opening degree of the evaporation pressure adjusting valve is determined. The balance of the load on the valve body of the diaphragm type evaporation pressure regulating valve is expressed by the following formula F5 when the pressure receiving area of the valve body and the pressure receiving area of the bellows are equal.
P1 × Abf = Ksb × L + F0 + P0 × Abf (F5)
Here, P1 is the refrigerant pressure on the inflow passage side, Abf is the pressure receiving area of the diaphragm, P0 is the pressure of the reference gas (that is, atmospheric pressure) in the cladding tube, Ksb is the spring constant of the spring, and L is the amount of displacement of the valve body. , F0 is an initial load such as a spring.

By transforming the formula F5, it can be expressed as the following formula F6.
P1 = Ksb / Abf × L + F0 / Abf + P0 (F6)
According to the mathematical formula F6, the refrigerant pressure on the inflow path side increases as the displacement amount L increases even in the diaphragm evaporation pressure regulating valve. In the diaphragm type evaporation pressure regulating valve, atmospheric pressure is used as a reference pressure, and the reference pressure shows a constant value regardless of the displacement of the valve body as shown in Formula F6.

Here, regarding Formula F4 and Formula F6, focusing on the coefficient (ie, pressure gradient) with respect to the displacement L, the pressure gradient of the diaphragm evaporation pressure regulating valve is influenced by the spring constant of the spring and the pressure receiving area of the diaphragm. That is, in the diaphragm type, only the spring constant of the spring is affected, and in the bellows type, the combined spring constant of the spring and the bellows is affected.

Therefore, in the diaphragm type evaporation pressure adjusting valve, the difference between the refrigerant evaporation pressure of the evaporator at the maximum flow rate and the minimum flow rate of the evaporator is smaller than that of the bellows type evaporation pressure adjusting valve. That is, as shown in FIG. 3, the pressure gradient of the diaphragm type evaporation pressure adjusting valve is smaller than the pressure gradient of the bellows type evaporation pressure adjusting valve.

Considering the pressure gradient in the evaporating pressure adjusting valve 19 and the pressure gradient of the diaphragm evaporating pressure adjusting valve based on the above-described equations F2 and F6. The pressure gradient of the evaporating pressure adjusting valve 19 and the pressure gradient of the diaphragm evaporating pressure adjusting valve are both obtained by dividing the spring constant of the spring energizing the valve body by the pressure receiving area receiving the refrigerant pressure on the inflow passage side. Expressed.

Here, the spring constant of the coil spring 61 in the evaporation pressure regulating valve 19 is formed small by making the pressure receiving area of the small diameter portion 60 of the valve body 55 sufficiently smaller than the pressure receiving area of the large diameter portion 56. Accordingly, the spring constant of the coil spring 61 is smaller than the spring constant of the spring in the diaphragm type evaporation pressure adjusting valve.

On the other hand, in the diaphragm type evaporation pressure regulating valve, the rubber diaphragm needs to have a configuration in which the thin film portion is folded in order to ensure the displacement amount of the valve body. Due to this configuration, the pressure receiving area of the diaphragm is formed larger than the flow path area of the inflow channel. Therefore, compared with the pressure receiving area of the small diameter portion 60, the pressure receiving area of the diaphragm is much larger.

Because of this relationship, in the evaporation pressure adjustment valve 19, the difference between the refrigerant evaporation pressure of the evaporator at the maximum flow rate and the minimum flow rate is smaller than that of the diaphragm type evaporation pressure adjustment valve. That is, as shown in FIG. 3, the pressure gradient of the evaporation pressure adjusting valve 19 is smaller than the pressure gradient of the bellows type evaporation pressure adjusting valve and the pressure gradient of the diaphragm type evaporation pressure adjusting valve.

As described above, the evaporation pressure regulating valve according to the first embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1, and the refrigerant in the indoor evaporator 18. The evaporating pressure P1 is adjusted to be equal to or higher than the frosting suppression pressure Ape.

The evaporating pressure adjusting valve 19 accommodates a valve body 55 having a small diameter portion 60 and a large diameter portion 56 in a valve chamber 51 in the body 40 so as to be displaceable, from the refrigerant inflow passage 42 to the refrigerant outflow passage 43. The area of the refrigerant flow path of the refrigerant is adjusted by the displacement of the valve body 55.

The small-diameter portion 60 formed in a shaft shape extends to the opening adjustment chamber 53 adjacent to the valve chamber 51 through the insertion hole 48, and the elastic force of the coil spring 61 disposed in the opening adjustment chamber 53. And the pressure of the atmosphere as a reference gas introduced into the opening adjustment chamber 53 is received.

That is, the evaporation pressure adjusting valve 19 is based on the refrigerant pressure on the refrigerant inflow passage 42 side applied to the small diameter portion 60 of the valve body 55, the pressure difference between the reference gas in the opening adjustment chamber 53, and the elastic force of the coil spring 61. The refrigerant evaporating pressure P1 in the indoor evaporator 18 can be adjusted by determining the opening degree of the refrigerant flow path.

Here, the small-diameter portion 60 of the valve body 55 is formed to have a pressure receiving area sufficiently smaller than that of the large-diameter portion 56, and no other external force is required to determine the opening degree. The difference in refrigerant evaporation pressure P1 between the maximum flow rate and the minimum flow rate can be made sufficiently small.

Further, in the evaporating pressure adjusting valve 19, the refrigerant permeation to the outside of the refrigerant circuit of the refrigeration cycle apparatus 10 may occur between the inner peripheral surface of the insertion hole 48 and the outer peripheral surface of the small diameter portion 60. is there. For this reason, according to the evaporation pressure adjusting valve 19, the refrigerant flow through the insertion hole 48 between the valve chamber 51 and the opening adjusting chamber 53 is blocked by arranging the O-ring 71 as a seal member. Therefore, refrigerant permeation to the outside of the refrigerant circuit of the refrigeration cycle apparatus 10 can be suppressed.

The O-ring 71 is made of nitrile rubber, ethylene propylene rubber, or the like, and is disposed so as to block between the outer peripheral surface of the small diameter portion 60 and the inner wall surface of the insertion hole 48. Therefore, since the refrigerant permeation area in the O-ring 71 is in a very small range of the gap between the small diameter portion 60 and the insertion hole 48, the evaporating pressure adjusting valve 19 has the refrigerant flow from the valve chamber 51 through the insertion hole 48. Leakage can be minimized.

Furthermore, the evaporation pressure adjusting valve 19 is configured to introduce the atmosphere as a reference gas into the opening degree adjusting chamber 53 via the atmosphere introducing hole 54. Therefore, according to the evaporation pressure adjusting valve 19, the pressure of the reference gas can be maintained when the valve body 55 is displaced, and the influence of the reference pressure on the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate is eliminated. Can do.

(Second Embodiment)
Next, a second embodiment different from the first embodiment described above will be described with reference to FIGS. 4 and 5. The evaporation pressure regulating valve 19 according to the second embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1, and functions as a seal member in the present disclosure. Except for the configuration and arrangement, the configuration is basically the same as that of the first embodiment. Accordingly, in the following description, the same reference numerals as those in the first embodiment indicate the same configuration, and the preceding description is referred to.

The evaporation pressure regulating valve 19 according to the second embodiment is adjusted in the refrigeration cycle apparatus 10 so that the refrigerant evaporation pressure P1 in the indoor evaporator 18 is equal to or higher than the frosting suppression pressure APe, as in the first embodiment. Yes.

As shown in FIG. 4, the evaporation pressure regulating valve 19 according to the second embodiment accommodates a valve body 55 having a small diameter portion 60 and a large diameter portion 56 in a valve chamber 51 in a body 40 so as to be displaceable. The refrigerant flow area of the refrigerant from the refrigerant inflow path 42 to the refrigerant outflow path 43 is adjusted by the displacement of the valve body 55.

Also in the second embodiment, the small diameter portion 60 is formed in an axial shape extending from the large diameter portion 56 and is inserted into the insertion hole 48. The tip of the small diameter portion 60 protrudes into the opening degree adjusting chamber 53 adjacent to the valve chamber 51 through the insertion hole 48. A coil spring 61 is arranged inside the opening adjustment chamber 53, and the atmosphere as a reference gas is introduced through the atmosphere introduction hole 54.

Therefore, the evaporating pressure adjusting valve 19 according to the second embodiment includes the refrigerant pressure on the refrigerant inflow path 42 side applied to the small diameter portion 60 of the valve body 55 and the pressure difference between the reference gas in the opening adjustment chamber 53 and the coil spring 61. The degree of opening of the refrigerant flow path can be determined by the elastic force, and the refrigerant evaporation pressure P1 in the indoor evaporator 18 can be adjusted.

As shown in FIGS. 4 and 5, in the evaporation pressure regulating valve 19 according to the second embodiment, a metal bellows 72 is disposed inside the opening degree regulating chamber 53. The bellows 72 is a bottomed cylindrical member formed to be extendable in the displacement direction of the valve body 55 (the axial direction of the body), and is arranged coaxially with the cylindrical portion 46 and the small diameter portion 60. The peripheral surface of the bellows 72 is formed in a bellows shape, and the bellows-like peripheral surface realizes the stretchability of the bellows 72.

The bellows 72 is arranged so that the inner space of the bellows 72 formed in a bottomed cylindrical shape is connected to the valve chamber 51 through the insertion hole 48. Therefore, the end portion of the small diameter portion 60 inserted through the insertion hole 48 is disposed inside the bottomed cylindrical bellows 72. And the bottom part of the bellows 72 is arrange | positioned between the front-end | tip part of the small diameter part 60, and the one end part of the coil spring 61 arrange | positioned in the opening degree adjustment chamber 53. FIG.

As shown in FIG. 5, the end portion of the bellows 72 positioned on the insertion hole 48 side is joined to the concave portion 49 in the cylinder portion 45 in which the insertion hole 48 is formed. The bellows 72 is arranged so that the opening edge of the bellows 72 is located radially outside the opening edge of the insertion hole 48 and is connected over the entire circumference of the opening edge.

In the evaporation pressure regulating valve 19 according to the second embodiment, by arranging the bellows 72 in this way, the refrigerant traveling from the valve chamber 51 to the opening adjusting chamber 53 through the insertion hole 48 is retained in the bellows 72. ing. That is, the bellows 72 functions as a seal member in the present disclosure.

As described above, the evaporation pressure regulating valve 19 according to the second embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1, and is provided in the indoor evaporator 18. The refrigerant evaporating pressure P1 is adjusted to be equal to or higher than the frosting suppression pressure Ape.

The evaporating pressure adjusting valve 19 is configured in the same manner as in the first embodiment except for a member used as a sealing member. Therefore, also in the second embodiment, the small diameter portion 60 of the valve body 55 is formed so as to have a pressure receiving area sufficiently smaller than that of the large diameter portion 56, and no other external force is required to determine the opening degree.

That is, the evaporation pressure adjusting valve 19 according to the second embodiment exhibits the same effect as that of the first embodiment, and the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate in the indoor evaporator 18 is obtained. It can be made sufficiently small.

Further, in the opening adjustment chamber 53 in the second embodiment, a metal bellows 72 formed in a bottomed cylindrical shape has its internal space connected to the valve chamber 51 through the insertion hole 48. And is joined to the recess 49. Therefore, the bellows 72 according to the second embodiment can keep the refrigerant from the valve chamber 51 to the opening adjustment chamber 53 through the insertion hole 48 inside the bellows 72, and functions as a seal member in the present disclosure. .

And according to the evaporation pressure regulating valve 19 according to the second embodiment, the flow of the refrigerant through the insertion hole 48 between the valve chamber 51 and the opening degree regulating chamber 53 by disposing the bellows 72 as the seal member. Therefore, the permeation of the refrigerant to the outside of the refrigerant circuit of the refrigeration cycle apparatus 10 can be suppressed.

Furthermore, the evaporation pressure regulating valve 19 according to the second embodiment is also configured to introduce the atmosphere as the reference gas into the opening degree adjusting chamber 53 through the atmosphere introducing hole 54. Therefore, also in the second embodiment, the pressure of the reference gas can be maintained when the valve body 55 is displaced, and the influence of the reference pressure on the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate can be eliminated.

(Third embodiment)
Next, a third embodiment different from the above-described embodiments will be described with reference to FIGS. The evaporation pressure regulating valve 19 according to the third embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1, and functions as a seal member in the present disclosure. Except for the configuration and arrangement, the configuration is basically the same as that of the above-described embodiment. Accordingly, also in the description of the third embodiment, the same reference numerals as those in the above-described embodiment indicate the same configuration, and the preceding description is referred to.

The evaporation pressure adjusting valve 19 according to the third embodiment is adjusted in the refrigeration cycle apparatus 10 so that the refrigerant evaporation pressure P1 in the indoor evaporator 18 is equal to or higher than the frosting suppression pressure APe in the same manner as in the above-described embodiment. Yes.

As shown in FIG. 6, the evaporation pressure regulating valve 19 according to the third embodiment accommodates a valve body 55 having a small diameter portion 60 and a large diameter portion 56 in a valve chamber 51 in a body 40 so as to be displaceable. The refrigerant flow area of the refrigerant from the refrigerant inflow path 42 to the refrigerant outflow path 43 is adjusted by the displacement of the valve body 55.

Also in the third embodiment, the small diameter portion 60 is formed in an axial shape extending from the large diameter portion 56 and is inserted into the insertion hole 48. The tip of the small diameter portion 60 protrudes into the opening degree adjusting chamber 53 adjacent to the valve chamber 51 through the insertion hole 48. A coil spring 61 is arranged inside the opening adjustment chamber 53, and the atmosphere as a reference gas is introduced through the atmosphere introduction hole 54.

Accordingly, the evaporating pressure adjusting valve 19 according to the third embodiment includes a difference between the refrigerant pressure on the refrigerant inflow path 42 side applied to the small diameter portion 60 of the valve body 55 and the pressure difference between the reference gas in the opening adjustment chamber 53 and the coil spring 61. The degree of opening of the refrigerant flow path can be determined by the elastic force, and the refrigerant evaporation pressure P1 in the indoor evaporator 18 can be adjusted.

As shown in FIGS. 6 and 7, a metal diaphragm 73 is disposed inside the opening adjustment chamber 53 of the evaporation pressure adjustment valve 19 according to the third embodiment. The diaphragm 73 has a stretchable film portion 73 a formed in an accordion shape, and partitions the inside of the opening adjustment chamber 53 through a space between the small diameter portion 60 inserted through the insertion hole 48 and the coil spring 61. Are arranged to be. The expansion and contraction of the stretchable film portion 73a allows the displacement of the valve body 55 via the small diameter portion 60.

As shown in FIG. 7, the diaphragm 73 divides the inside of the opening adjustment chamber 53 into two, and the outer edge of the stretchable film portion 73 a in the diaphragm 73 is all around the inner wall surface of the opening adjustment chamber 53. Are joined.

Accordingly, the diaphragm 73 can keep the refrigerant from the valve chamber 51 through the insertion hole 48 in the space on the insertion hole 48 side in the opening adjustment chamber 53 partitioned by the diaphragm 73, and the evaporation pressure adjustment valve 19 Leakage of refrigerant to the outside can be prevented. That is, the diaphragm 73 functions as a seal member in the present disclosure.

As described above, the evaporation pressure regulating valve according to the third embodiment is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1, and the refrigerant in the indoor evaporator 18. The evaporating pressure P1 is adjusted to be equal to or higher than the frosting suppression pressure Ape.

The evaporating pressure adjusting valve 19 is configured in the same manner as the above-described embodiment except for a member used as a sealing member. Therefore, also in the third embodiment, the small diameter portion 60 of the valve body 55 is formed to have a pressure receiving area sufficiently smaller than that of the large diameter portion 56, and no other external force is required for determining the opening degree.

That is, the evaporation pressure adjusting valve 19 according to the third embodiment exhibits the same effect as that of the above-described embodiment, and the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate in the indoor evaporator 18 is obtained. It can be made sufficiently small.

In addition, inside the opening adjustment chamber 53 in the third embodiment, a metal diaphragm 73 is interposed between the small diameter portion 60 inserted through the insertion hole 48 and the coil spring 61 and the opening adjustment chamber 53. It is arranged so as to partition the inside.

Therefore, the evaporating pressure adjusting valve 19 according to the third embodiment uses the diaphragm 73 as a seal member, so that the refrigerant from the valve chamber 51 is separated from the valve chamber 51 through the insertion hole 48 and the opening adjusting chamber 53 partitioned by the diaphragm 73. It is possible to prevent the refrigerant from leaking to the outside of the evaporating pressure adjusting valve 19.

Furthermore, the evaporating pressure regulating valve 19 according to the third embodiment is also configured to introduce the atmosphere as the reference gas into the opening degree adjusting chamber 53 through the atmosphere introducing hole 54. Therefore, also in the third embodiment, the pressure of the reference gas can be maintained when the valve body 55 is displaced, and the influence of the reference pressure on the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate can be eliminated.

(Other embodiments)
Although the embodiment has been described above, the present invention is not limited to the embodiment described above. That is, various improvements and modifications can be made without departing from the spirit of the present invention. For example, the above-described embodiments may be combined as appropriate, and the above-described embodiments may be variously modified.

(1) In the embodiment described above, the flow of the refrigerant from the valve chamber 51 toward the opening adjustment chamber 53 through the insertion hole 48 using the rubber O-ring 71, the metal bellows 72, and the diaphragm 73. Although it interrupted | blocked, the sealing member in this indication is not limited to this mode. If the leakage of the refrigerant from the valve chamber 51 to the outside of the evaporation pressure regulating valve 19 can be reduced via the insertion hole 48 as the seal member in the present disclosure, the constituent material, shape, and the like can be appropriately changed.

(2) In the above-described embodiment, the evaporation pressure adjusting valve 19 is disposed between the indoor evaporator 18 and the compressor 11 in the refrigeration cycle apparatus 10 of the vehicle air conditioner 1. It is not limited to. What is necessary is just to arrange | position between the evaporator and compressor in a vapor compression refrigeration cycle, and the use as the refrigeration cycle is not limited to a vehicle air conditioner.

(3) In the above-described embodiment, the atmosphere introduced through the atmosphere introduction hole 54 is used as the reference gas in the opening degree adjustment chamber 53. However, the present invention is not limited to this mode. For example, a configuration in which a reference gas is sealed in the opening adjustment chamber 53 is also possible. Even in this configuration, since the pressure receiving area of the small-diameter portion is sufficiently small, the difference between the refrigerant evaporation pressure P1 at the maximum flow rate and the minimum flow rate by the evaporation pressure adjusting valve 19 can be reduced.

Claims (5)

1. An evaporation pressure adjusting valve (19) which is disposed between the evaporator (18) and the compressor (11) in the refrigeration cycle (10) and adjusts the refrigerant evaporation pressure in the evaporator to be equal to or higher than a predetermined reference evaporation pressure. ) And
   A body (40) having a valve chamber (51) formed therein;
   A refrigerant inflow path (42) provided in the body and into which the refrigerant flows from the evaporator into the valve chamber;
   A refrigerant outflow path (43) provided in the body and through which refrigerant flows out from the valve chamber to the compressor;
   A large-diameter portion (56) that is slidably disposed in a predetermined direction in response to the pressure on the refrigerant inflow passage side in the valve chamber, and changes the opening of the refrigerant flow passage that flows to the refrigerant outflow passage, and the large diameter A valve body (55) including a shaft-like small diameter portion (60) extending in the predetermined direction from the large diameter portion with an area smaller than the portion;
   A reference that is disposed adjacent to the valve chamber in the predetermined direction and has an insertion hole (48) that is inserted through the small diameter portion of the valve body, and that is referred to when determining the opening of the refrigerant flow path. An opening adjustment chamber (53) having a reference gas for generating pressure therein;
   An elastic member (61) disposed inside the opening adjustment chamber and biasing the small diameter portion of the valve body in a closing direction to reduce the opening of the refrigerant flow path;
   An evaporating pressure adjusting valve comprising: a seal member (71, 72, 73) that blocks the flow of the refrigerant through the insertion hole between the valve chamber and the opening degree adjusting chamber.
2. 2. The evaporation pressure regulating valve according to claim 1, wherein the seal member is configured by an O-ring (71) disposed so as to block between an outer peripheral surface of the small diameter portion and an inner peripheral surface of the insertion hole. .
3. The seal member is formed of a metal bellows (72) having a cylindrical shape with a bottom and a peripheral surface formed in a bellows shape,
   Inside the seal member, an end portion of the small diameter portion inserted through the insertion hole is accommodated,
   The evaporation pressure regulating valve according to claim 1, wherein an opening end of the seal member is joined to the insertion hole inside the opening degree adjusting chamber.
4. The seal member is configured by a metal diaphragm (73) arranged so as to be partitioned between the small diameter portion inserted through the insertion hole and the elastic member in the opening degree adjusting chamber. The evaporation pressure regulating valve according to claim 1.
5. The opening adjustment chamber has an air introduction hole (54) that communicates the inside of the opening adjustment chamber and the outside of the body,
   The evaporation pressure regulating valve according to any one of claims 1 to 4, wherein the atmosphere introduced through the atmosphere introduction hole has inside as the reference gas.
   
   

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