JP2017149294A - Vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular air conditioner capable of performing a defrosting operation easily and effectively.SOLUTION: A vehicular air conditioner includes: a compressor for compressing and discharging a refrigerant; an indoor heat exchanger that radiates heat by using a refrigerant discharged from the compressor; an outdoor heat exchanger for exchanging heat between the refrigerant discharged from the indoor heat exchanger and the outdoor atmosphere; an accumulator 47 disposed on the upstream side in the flowing direction of the refrigerant of the compressor, separating the refrigerant into gas and liquid and causing the gas-phase refrigerant to flow toward the compressor; and a PTC thermistor 62 provided in the accumulator 47. During a defrosting operation for defrosting the outdoor heat exchanger, heat of the refrigerant discharged from the compressor is radiated by the outdoor heat exchanger, and the refrigerant in the accumulator is heated by the PTC thermistor 62.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle air conditioner.

  In a vehicle that does not include an engine as a vehicle drive source, such as an electric vehicle, a vehicle air conditioner using a heat pump cycle is employed because the engine coolant cannot be used during heating. In this type of vehicle air conditioner, the cooling operation and the heating operation are switched by switching the flow of the refrigerant discharged from the compressor.

Specifically, in the heating operation, the refrigerant discharged from the compressor is dissipated in the indoor heat exchanger, and then expanded by the heating expansion valve, then absorbs heat in the outdoor heat exchanger and is sucked into the compressor again. The The conditioned air is heated by passing through the indoor heat exchanger, and is supplied to the vehicle interior as heating.
On the other hand, in the cooling operation, the refrigerant discharged from the compressor is dissipated in the outdoor heat exchanger, is then expanded by the cooling expansion valve, absorbs heat in the indoor heat exchanger, and is sucked into the compressor again. The conditioned air is cooled by passing through the indoor heat exchanger, and is supplied to the passenger compartment as cooling.

  By the way, in the vehicle air conditioner described above, in the heating operation, the refrigerant absorbs heat from the outdoor atmosphere by the outdoor heat exchanger, so that frost may adhere to the outdoor heat exchanger. If frost adheres to the outdoor heat exchanger, the heat transfer rate decreases and the heat absorption becomes insufficient, so that the heating of the vehicle interior may be insufficient.

  Then, the structure which performs the defrost operation which dissipates a refrigerant | coolant with an outdoor heat exchanger when frost has adhered to the outdoor heat exchanger is known. For example, Patent Document 1 below discloses a configuration in which the refrigerant pressure in the outdoor heat exchanger is increased by heating the refrigerant in the accumulator provided on the upstream side of the compressor with a heater during the defrosting operation. Has been.

JP-A-2-258467

  However, the amount of liquid-phase refrigerant accommodated in the accumulator varies depending on the operation load of the heat pump cycle. In this case, in the configuration of Patent Document 1 described above, it is considered necessary to control the electric power supplied to the heater in accordance with the amount of refrigerant in order to suppress idling of the accumulator and the like. As a result, it is necessary to monitor the state in the accumulator over a wide range, and the control of the heater may be complicated.

  Then, this invention was made | formed in view of the situation mentioned above, and it aims at providing the vehicle air conditioner which can perform a defrost operation simply and effectively.

  In order to achieve the above object, the invention described in claim 1 includes a compressor that compresses and discharges a refrigerant (for example, the compressor 41 in the embodiment), and an indoor heat exchanger that radiates heat by the refrigerant discharged from the compressor. (For example, the indoor heat exchanger 26 in the embodiment) and an outdoor heat exchanger that performs heat exchange between the refrigerant discharged from the indoor heat exchanger and the outdoor atmosphere (for example, the outdoor heat exchanger 43 in the embodiment). And an accumulator (e.g., an accumulator 47 in the embodiment) that is disposed upstream of the compressor in the refrigerant flow direction and separates the gas-liquid refrigerant and circulates the gas-phase refrigerant toward the compressor, A PTC thermistor (for example, the PTC thermistor 62 in the embodiment) provided in the accumulator; For example, during the defrosting operation to perform defrosting of the outdoor heat exchanger, the refrigerant discharged from the compressor, as well as heat dissipation in the outdoor heat exchanger to heat the refrigerant in the accumulator by the PTC thermistor.

  In the invention described in claim 2, the accumulator includes a case (for example, the case 61 in the embodiment) that stores a refrigerant, and a thermistor housing portion (for example, in the embodiment) that is provided in the case and houses the PTC thermistor. The PTC thermistor includes a heating element (for example, the heating element 95 in the embodiment) and a pair of electrode plates (for example, the electrode plates 96 and 97 in the embodiment) that sandwich the heating element. In the thermistor housing part, a wedge member (for example, the wedge members 110 and 111 in the embodiment) may be interposed between the inner surface of the thermistor housing part and the electrode plate.

  In the invention described in claim 3, the accumulator includes a case (for example, the case 210 in the embodiment) that stores a refrigerant, and a thermistor storage portion (for example, in the embodiment) that is provided in the case and stores the PTC thermistor. A thermistor housing part 213), the PTC thermistor comprising a heating element and a pair of electrode plates sandwiching the heating element, and the thermistor housing part includes the PTC thermistor as the heating element and the electrode. A caulking portion (for example, the side wall portion 213a in the embodiment) that is sandwiched in the stacking direction of the plates may be provided.

  In the invention described in claim 4, the accumulator is provided in a bottomed cylindrical case (for example, the case 61 in the embodiment) that accommodates the refrigerant, and a cylindrical portion of the case (for example, the cylindrical portion 64b in the embodiment). A thermistor accommodating portion (for example, the thermistor accommodating portion 92 in the embodiment) that is formed and is recessed inward in the radial direction of the cylindrical portion, and that accommodates the PTC thermistor.

  In the invention described in claim 5, the accumulator includes a bottomed cylindrical case (for example, the case 301 in the embodiment) that contains a refrigerant, and the PTC thermistor includes a bottom wall portion (for example, an implementation) of the case. It may be fixed to the bottom wall 303) in the form.

According to the structure described in Claim 1, the PTC thermistor provided in the accumulator is operated during the defrosting operation. Then, the liquid phase refrigerant stored in the accumulator is heated by the heat generated by the PTC thermistor. As a result, the liquid-phase refrigerant evaporates into a gas-phase refrigerant. The refrigerant that has become a gas phase flows out of the accumulator, is then sucked into the compressor, and is subjected to the dehumidifying operation described above. As described above, by operating the PTC thermistor during the defrosting operation, it is possible to increase the flow rate of the gas-phase refrigerant flowing in the outdoor heat exchanger 43. Thereby, the amount of heat radiation in the outdoor heat exchanger can be increased, and the defrosting operation can be performed effectively.
In particular, a PTC thermistor is used as means for heating the refrigerant in the accumulator. According to this configuration, for example, when the heating element is overheated to a predetermined temperature (Curie temperature) due to, for example, a decrease in the liquid-phase refrigerant in the accumulator, the resistance value increases rapidly and current is supplied to the PTC thermistor. Are automatically restricted (OFF state). For this reason, it is possible to suppress the idling of the accumulator and the like without performing complicated power control as in the prior art. As a result, the defrosting operation can be performed easily and effectively.

According to the second aspect of the present invention, since the wedge member is interposed between the inner surface of the thermistor housing and the electrode plate of the PTC thermistor, the heating element of the PTC thermistor and each electrode plate are firmly in close contact. Can be made. Thereby, it can suppress that each electrode plate separates from a heat generating element, and can ensure the stable operation | movement reliability over a long term.
In addition, since the wedge member is disposed without a gap between the inner surface of the thermistor housing and the electrode plate of the PTC thermistor, the heat generated in the PTC thermistor can be effectively transferred to the refrigerant in the accumulator.

According to the configuration described in claim 3, the PTC thermistor is sandwiched in the stacking direction by the caulking portion in the thermistor housing portion, whereby the heating element of the PTC thermistor and each electrode plate can be firmly brought into close contact with each other. Thereby, it can suppress that each electrode plate separates from a heat generating element, and can ensure the stable operation | movement reliability over a long term.
Moreover, the heat which generate | occur | produced in the PTC thermistor can be effectively transmitted to the refrigerant | coolant in an accumulator by making the inner surface of the crimping part in a thermistor accommodating part and the electrode plate of a PTC thermistor contact.

  According to the structure described in Claim 4, the refrigerant | coolant accommodated in a case can be effectively heated by forming in the cylinder part of a case the thermistor accommodating part hollow in a radial inside.

  According to the structure described in Claim 5, a PTC thermistor can be easily attached to a case by attaching a PTC thermistor to the bottom wall part of a case.

It is a block diagram of a vehicle air conditioner. It is a cross-sectional view along the radial direction of the accumulator which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which follows the axial direction of the accumulator which concerns on 1st Embodiment. It is the IV section enlarged view of FIG. It is explanatory drawing for demonstrating the heating operation of a vehicle air conditioner. It is explanatory drawing for demonstrating the air_conditionaing | cooling operation of a vehicle air conditioner. It is explanatory drawing for demonstrating the dehumidification driving | operation of a vehicle air conditioner. It is explanatory drawing for demonstrating the defrost operation of a vehicle air conditioner, Comprising: (A) shows hot gas operation and (B) has shown reverse rotation defrost operation. It is a longitudinal cross-sectional view which follows the axial direction of the accumulator which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which follows the axial direction of the accumulator which concerns on the modification of 2nd Embodiment. It is a fragmentary sectional view of the accumulator concerning a 3rd embodiment.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
[Vehicle air conditioner]
FIG. 1 is a configuration diagram of a vehicle air conditioner 10.
As shown in FIG. 1, the vehicle air conditioner 10 of this embodiment is mounted on a vehicle (for example, an electric vehicle) that does not include an engine (internal combustion engine) as a vehicle drive source, for example. Specifically, the vehicle air conditioner 10 mainly includes an air conditioning unit 11 and a heat pump cycle 12 capable of circulating the refrigerant.

The air conditioning unit 11 includes a duct 21 through which conditioned air flows, and an inside / outside air door 22, a blower 23, an evaporator 24, an air mix door 25, and an indoor heat exchanger 26 accommodated in the duct 21.
The duct 21 has an inside air inlet 31 and an outside air inlet 32 formed on the upstream side in the flow direction of the conditioned air, and a blowout port 33 formed on the downstream side. The inside / outside air door 22, the blower 23, the evaporator 24, the air mix door 25, and the indoor heat exchanger 26 described above are arranged in this order from the upstream side in the flow direction to the downstream side in the duct 21.

The inside / outside air door 22 rotates between an inside air intake position where the inside air intake port 31 is opened and an outside air intake position where the outside air intake port 32 is opened. Thereby, the flow rate ratio of inside air and outside air among the conditioned air flowing into the duct 21 is adjusted.
The blower 23 sends conditioned air (at least one of internal air and external air) taken into the duct 21 through the intake ports 31 and 32 to the downstream side.

  The evaporator 24 performs heat exchange between the low-pressure refrigerant flowing into the interior and the vehicle interior atmosphere (in the duct 21), and cools the conditioned air passing through the evaporator 24 by, for example, heat absorption when the refrigerant evaporates.

  The indoor heat exchanger 26 performs heat exchange between the high-temperature and high-pressure refrigerant flowing into the interior and the vehicle interior atmosphere (in the duct 21), and heats the conditioned air passing through the indoor heat exchanger 26, for example.

  The air mix door 25 includes a heating position (see FIG. 5) in the duct 21 that opens the ventilation path (heating path) that passes through the indoor heat exchanger 26 and goes to the outlet 33, and the indoor heat exchanger 26. It rotates between a cooling position (see FIG. 6) that opens a ventilation path (cooling path) that detours toward the outlet 33. Thereby, among the conditioned air that has passed through the evaporator 24, the flow rate ratio between the flow rate that passes through the heating path and the flow rate that passes through the cooling path is adjusted.

  The heat pump cycle 12 includes, for example, the evaporator 24 and the indoor heat exchanger 26, the compressor 41, the heating expansion valve 42, the outdoor heat exchanger 43, the heating valve 44, the check valve 45, the cooling expansion valve 46, and the accumulator. 47 and a dehumidifying valve 48. The above-described components of the heat pump cycle 12 are connected via a refrigerant flow path 49.

  The compressor 41 is connected between the accumulator 47 and the indoor heat exchanger 26. The compressor 41 sucks the gas-phase refrigerant from the accumulator 47, compresses the refrigerant, and then discharges it to the indoor heat exchanger 26 described above as a high-temperature and high-pressure refrigerant.

  The expansion valve for heating 42 expands the refrigerant discharged from the indoor heat exchanger 26, and then discharges it to the outdoor heat exchanger 43 as a low-temperature, low-pressure gas-liquid two-phase (liquid phase rich) spray-like refrigerant. To do.

A bypass passage 51 that bypasses the heating expansion valve 42 is connected to the refrigerant passage 49. The bypass passage 51 is provided with a bypass valve 52 that adjusts the flow rate of the refrigerant flowing in the bypass passage 51. The bypass valve 52 is closed when the heating operation is performed, and is opened when the cooling operation is performed.
Thereby, for example, when the heating operation is performed, the refrigerant discharged from the indoor heat exchanger 26 passes through the heating expansion valve 42 and flows into the outdoor heat exchanger 43 in a low temperature and low pressure state.
On the other hand, during the cooling operation, the refrigerant discharged from the indoor heat exchanger 26 passes through the bypass valve 52 and flows into the outdoor heat exchanger 43 in a high temperature state.

  The outdoor heat exchanger 43 performs heat exchange between the refrigerant flowing into the interior and the outdoor atmosphere. Specifically, the outdoor heat exchanger 43 raises the temperature of the low-temperature and low-pressure refrigerant flowing into the interior by absorbing heat from the outdoor atmosphere during the heating operation. On the other hand, the outdoor heat exchanger 43 cools the high-temperature refrigerant flowing into the interior to the outdoor atmosphere by radiating heat during the cooling operation. The outdoor heat exchanger 43 has a larger refrigerant capacity than the indoor heat exchanger 26.

  A fan 50 capable of blowing air toward the outdoor heat exchanger 43 is disposed at a position facing the outdoor heat exchanger 43. In addition, the refrigerant flow path 49 described above is branched into a cooling flow path 55, a heating flow path 56, and a dehumidification flow path 57 on the downstream side of the outdoor heat exchanger 43.

The check valve 45 is installed on the cooling channel 55 described above in the refrigerant channel 49. The check valve 45 circulates the refrigerant that has passed through the outdoor heat exchanger 43 toward the downstream side during execution of the cooling operation. On the other hand, when the dehumidifying operation is performed, the check valve 45 causes the refrigerant flowing from the dehumidifying channel 57 into the cooling channel 55 to flow upstream from the check valve 45 (outside heat exchanger 43 side). To prevent.
The cooling expansion valve 46 is connected between the check valve 45 and the evaporator 24 in the cooling flow path 55. The cooling expansion valve 46 expands the refrigerant that has passed through the check valve 45 and then discharges it to the evaporator 24 as a gas-liquid two-phase (vapor-phase rich) atomized refrigerant at low temperature and low pressure.

  The heating valve 44 is installed on the heating channel 56 described above in the refrigerant channel 49. The heating valve 44 is opened when the heating operation is performed, and is closed when the cooling operation is performed. The heating flow path 56 joins the downstream side of the evaporator 24 in the cooling flow path 55 on the downstream side of the heating valve 44.

  The accumulator 47 is connected between the merging portion 59 that connects between the downstream end of the cooling passage 55 and the downstream end of the heating passage 56 in the refrigerant passage 49 and the compressor 41 described above. The accumulator 47 separates the gas-liquid refrigerant flowing from the junction 59 and causes the compressor 41 to suck the gas-phase refrigerant. The detailed configuration of the accumulator 47 will be described later.

  The dehumidifying valve 48 is installed on the dehumidifying channel 57 in the refrigerant channel 49 described above. The dehumidifying valve 48 is opened when the dehumidifying operation is performed, and is closed when other operations (such as cooling operation and heating operation) are performed. The dehumidifying channel 57 includes a portion of the refrigerant channel 49 that is positioned on the downstream side of the check valve 45 in the cooling channel 55, and the indoor heat exchanger 26 and the heating expansion valve in the refrigerant channel 49. 42 is connected to the portion located between the two.

<Accumulator>
FIG. 2 is a cross-sectional view of the accumulator 47 along the radial direction. FIG. 3 is a longitudinal sectional view along the axial direction of the accumulator 47.
As shown in FIGS. 2 and 3, the accumulator 47 includes a case 61 that contains a refrigerant, and a PTC (Positive Temperature Coefficient) thermistor 62 that heats the refrigerant in the case 61.

  The case 61 includes a bottomed cylindrical case main body 64 and a lid 65 that closes an opening of the case main body 64. In the following description, a direction along the axis of the case main body 64 may be simply referred to as an axial direction, a direction orthogonal to the axis may be referred to as a radial direction, and a direction around the axis may be referred to as a circumferential direction. Further, in the present embodiment, in the axial direction, the bottom wall portion 64a side of the case main body 64 will be described as the lower side, and the lid body 65 side will be described as the upper side.

  As shown in FIG. 3, the lid body 65 is formed with a refrigerant inlet 71 and a refrigerant outlet 72 that pass through the lid body 65 in the axial direction. As shown in FIGS. 1 and 3, the refrigerant inlet 71 is connected to the downstream end of the junction 59 in the refrigerant flow path 49 described above. The refrigerant outlet 72 is connected to the upstream end of the connection flow path 75 that connects the accumulator 47 and the compressor 41 in the refrigerant flow path 49 described above.

As shown in FIG. 3, the case 61 is provided with a communication pipe 81 that allows communication between the case 61 and the refrigerant outlet 72. The communication pipe 81 includes an inner cylinder 82 and an outer cylinder 83 that surrounds the inner cylinder 82.
The inner cylinder 82 extends along the axial direction. The upper end portion of the inner cylinder 82 is connected to the refrigerant outlet 72.

The outer cylinder 83 is formed in a bottomed cylindrical shape arranged coaxially with the inner cylinder 82. The outer cylinder 83 surrounds the inner cylinder 82 from the outer side and the lower side in the radial direction with the upper portion of the inner cylinder 82 exposed. The outer cylinder 83 is connected to the inner cylinder 82 by a rib or the like (not shown).
The gap between the inner cylinder 82 and the outer cylinder 83 constitutes a bypass flow path 88 that connects the lower end opening of the inner cylinder 82 and the outer side of the outer cylinder 83. The bypass flow path 88 prevents the liquid-phase refrigerant from flowing into the inner cylinder 82 among the refrigerant in the case 61. On the other hand, the gas-phase refrigerant flows into the bypass channel 88 from above the outer cylinder 83.
An oil return hole 89 that penetrates the bottom wall portion in the axial direction is formed in the bottom wall portion of the outer cylinder 83. The oil return hole 89 is for guiding the oil (lubricating oil) contained in the liquid-phase refrigerant accommodated in the case 61 into the inner cylinder 82.

  A baffle 90 is provided on the upper part of the inner cylinder 82 (the part located above the upper end edge of the outer cylinder 83). The baffle 90 is formed in a circular shape smaller than the inner diameter of the case main body 64 in a plan view viewed from the axial direction. The baffle 90 is opposed to the above-described refrigerant inlet 71 and refrigerant outlet 72 in a state of being spaced apart in the axial direction. In the present embodiment, the refrigerant can pass between the outer peripheral edge of the baffle 90 and the inner peripheral surface of the cylindrical portion 64b of the case main body 64. However, the baffle 90 itself may be provided with a passage hole through which the refrigerant can pass. In this case, the baffle 90 may be fixed to the cylindrical portion 64b of the case main body 64.

  As shown in FIGS. 2 and 3, a thermistor accommodating portion 92 is formed in the lower portion of the cylindrical portion 64 b in the case main body 64. The thermistor accommodating portion 92 is recessed inward in the radial direction with respect to the outer peripheral surface of the cylindrical portion 64b. Further, the thermistor accommodating portion 92 is formed at a position that does not overlap the communication pipe 81 when viewed from the first direction in the radial direction. Further, the radially inner end portion of the thermistor accommodating portion 92 extends to a position overlapping the communication pipe 81 when viewed from the second direction orthogonal to the first direction in the radial direction.

FIG. 4 is an enlarged view of a portion IV in FIG.
As shown in FIG. 4, the PTC thermistor 62 includes a heating element 95 and a pair of electrode plates (a first electrode plate 96 and a second electrode plate 97) that sandwich the heating element 95.
The heating element 95 is formed in a plate shape. The heating element 95 is an element whose electric resistance increases as the temperature rises. As the heating element 95, a material such as a ceramic material or a mixed material of resin and carbon is preferably used.
The electrode plates 96 and 97 are stacked separately on opposite surfaces of the heating element 95. Lead wires (not shown) for supplying power to the electrode plates 96 and 97 are connected to the electrode plates 96 and 97, respectively. In the following description, in the PTC thermistor 62, the stacking direction of the heating element 95 and the electrode plates 96 and 97 may be simply referred to as the stacking direction.

  The heat transfer sheets 100 are laminated on both sides of the PTC thermistor 62 in the lamination direction. The heat transfer sheet 100 is made of a material (for example, a silicone resin) having insulating properties and excellent thermal conductivity. The heat transfer sheet 100 is in close contact with the electrode plates 96 and 97 of the PTC thermistor 62. The heat transfer sheet 100 is larger than the PTC thermistor 62 in plan view as viewed from the stacking direction. However, the outline of the heat transfer sheet 100 in plan view can be changed as appropriate.

  In the stacking direction of the PTC thermistors 62, insulating sheets 101 are stacked on the opposite side of the PTC thermistor 62 with the heat transfer sheet 100 interposed therebetween. The insulating sheet 101 is made of alumina or the like, for example. The insulating sheet 101 is intended to insulate between the PTC thermistor 62 and the case 61. In addition, the planar view shape of the insulating sheet 101 is the same size as the heat transfer sheet 100.

  Here, the PTC thermistor 62 described above is described above in a state where the PTC thermistor 62 is sandwiched in the stacking direction by the pair of wedge members (the first wedge member 110 and the second wedge member 111) together with the heat transfer sheet 100 and the insulating sheet 101 described above. The thermistor accommodating portion 92 is fitted. In the present embodiment, the PTC thermistor 62 is fitted into the thermistor housing portion 92 with the first extending direction being along the opening direction of the thermistor housing portion 92 among the in-plane directions orthogonal to the stacking direction. ing. Each wedge member 110, 111 is preferably formed of a material having excellent thermal conductivity such as an aluminum alloy.

  The first wedge member 110 is formed in a triangular shape in cross-sectional view along the stacking direction. Specifically, the portion of the outer surface of the first wedge member 110 that faces the inner surface of the thermistor housing portion 92 is formed following the shape of the inner surface of the thermistor housing portion 92. On the other hand, of the outer surface of the first wedge member 110, the portion facing the insulating sheet 101 (hereinafter referred to as the first contact surface 110 a) has a thickness of the first wedge member 110 toward the opening of the thermistor housing portion 92. The slanted surface is thinned. In this case, the PTC thermistor 62 is in contact with the first contact surface 110a of the first wedge member 110 via the insulating sheet 101 and the heat transfer sheet 100 located on the first electrode plate 96 side. That is, the PTC thermistor 62 is disposed in the thermistor housing portion 92 with the first extending direction inclined with respect to the opening direction of the thermistor housing portion 92.

  The second wedge member 111 is formed in a triangular shape in a sectional view along the stacking direction. Specifically, the portion of the outer surface of the second wedge member 111 that faces the inner surface of the thermistor housing portion 92 is formed following the inner surface shape of the thermistor housing portion 92. On the other hand, of the outer surface of the second wedge member 111, the portion facing the insulating sheet 101 (hereinafter referred to as the second contact surface 111 a) has a thickness of the second wedge member 111 toward the opening of the thermistor housing portion 92. The slope is thickened. In this case, the PTC thermistor 62 is in contact with the second contact surface 111a of the second wedge member 111 via the insulating sheet 101 and the heat transfer sheet 100 located on the second electrode plate 97 side. As a result, the PTC thermistor 62 is fitted into the thermistor housing portion 92 with the first extending direction inclined with respect to the opening direction of the thermistor housing portion 92 and being sandwiched between the wedge members 110 and 111 in the stacking direction. ing.

  The PTC thermistor 62, the heat transfer sheets 100, the insulating sheets 101, and the second wedge members 111 described above are inserted into the thermistor housing portion 92 in a state of being bundled in the stacking direction by the holding jig 115. That is, when the PTC thermistor 62 of this embodiment is fitted into the thermistor housing portion 92, the first wedge member 110 is first inserted into the thermistor housing portion 92. Thereafter, the PTC thermistor 62, each heat transfer sheet 100, each insulating sheet 101, and the second wedge member 111 are inserted into the thermistor housing portion 92 in a state of being bundled by the holding jig 115. Then, the PTC thermistor 62 and the like (each heat transfer sheet 100, each insulating sheet 101, the second wedge member 111 and the like) are guided into the thermistor accommodating portion 92 along the first contact surface 110a of the first wedge member 110. .

  At this time, a gap between the first contact surface 110a of the first wedge member 110 and a portion of the inner surface of the thermistor housing portion 92 that faces the first contact surface 110a in the stacking direction is an opening of the thermistor housing portion 92. It becomes narrower as it gets away from the part. Therefore, as the PTC thermistor 62 and the like enter the thermistor housing portion 92, the second wedge member 111 is press-fitted into the thermistor housing portion 92. As a result, the PTC thermistor 62 is fitted into the thermistor housing portion 92 while being sandwiched between the wedge members 110 and 111 in the stacking direction. Note that the wedge member may have at least the second wedge member 111. That is, the PTC thermistor 62 may be configured such that the surface on the first electrode plate 96 side is in close contact with the inner surface of the thermistor housing portion 92.

  A spacer 116 is disposed between the heat generating element 95 and the holding jig 115 of the PTC thermistor 62 in the first extending direction to insulate the PTC thermistor 62 from the holding jig 115 and the thermistor housing 92. As shown in FIG. 2, a cap material 117 is provided in the opening of the thermistor housing portion 92. The cap material 117 prevents the PTC thermistor 62 from coming off and holds the above-described lead wire (not shown).

[Operation method of vehicle air conditioner]
Next, the operation of the above-described vehicle air conditioner 10 will be described. FIG. 5 is an explanatory diagram for explaining the heating operation of the vehicle air conditioner 10. In each of the following explanatory diagrams, in the refrigerant flow path 49, the chain line portion indicates the portion through which the high-pressure refrigerant flows, the solid line portion indicates the portion through which the low-pressure refrigerant flows, and the broken line portion indicates the portion through which the refrigerant does not flow. Is shown.
(Heating operation)
First, the heating operation of the vehicle air conditioner 10 will be described.
As shown in FIG. 5, during the heating operation, the air mix door 25 is set to the heating position, and the heating valve 44 is opened. During the heating operation, the bypass valve 52 and the dehumidifying valve 48 are closed.

In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 41 heats the conditioned air in the duct 21 by heat radiation in the indoor heat exchanger 26.
The refrigerant is expanded by the heating expansion valve 42 to form a gas-liquid two-phase (liquid-phase rich) spray. Thereafter, the refrigerant absorbs heat from the outdoor atmosphere in the outdoor heat exchanger 43 and becomes a gas-liquid two-phase (vapor-phase rich) spray. The refrigerant that has passed through the outdoor heat exchanger 43 passes through the heating valve 44 in the heating flow path 56 and then flows into the accumulator 47 through the junction 59.
Then, the refrigerant is gas-liquid separated in the accumulator 47, and the gas-phase refrigerant is sucked into the compressor 41.

Next, the flow of conditioned air in the heating operation will be described. In the heating operation, the conditioned air taken into the duct 21 may be inside air or outside air.
When the blower 23 is driven, conditioned air flows into the duct 21 through the intake ports 31 and 32. The conditioned air flowing into the duct 21 passes through the evaporator 24 and then passes through the indoor heat exchanger 26 in the heating path. The conditioned air is heated when passing through the indoor heat exchanger 26 in the heating path, and then supplied to the vehicle interior through the outlet 33 as heating.

(Cooling operation)
Next, the cooling operation of the vehicle air conditioner 10 will be described. FIG. 6 is an explanatory diagram for explaining the cooling operation of the vehicle air conditioner 10.
As shown in FIG. 6, during the cooling operation, the air mix door 25 is set to the cooling position, and the bypass valve 52 is opened. The heating valve 44 and the dehumidifying valve 48 are closed.

In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 41 passes through the indoor heat exchanger 26 and the bypass valve 52. Thereafter, the refrigerant is radiated to the outdoor atmosphere in the outdoor heat exchanger 43 and then flows into the cooling flow path 55. Then, the refrigerant is expanded by the cooling expansion valve 46 to form a gas-liquid two-phase (liquid-phase rich) spray. Thereafter, the refrigerant cools the conditioned air in the duct 21 by the heat absorption in the evaporator 24.
The gas-liquid two-phase (gas-phase rich) refrigerant that has passed through the evaporator 24 undergoes heat exchange with the gas-liquid two-phase (liquid-phase rich) refrigerant that has passed through the cooling expansion valve 46, and then the accumulator. 47 flows in. Thereafter, the refrigerant is gas-liquid separated in the accumulator 47, and then the gas-phase refrigerant is sucked into the compressor 41.

Next, the flow of conditioned air during the cooling operation described above will be described. In the cooling operation, the conditioned air taken into the duct 21 may be inside air or outside air.
The conditioned air flowing in the duct 21 is cooled when passing through the evaporator 24. Thereafter, the conditioned air bypasses the indoor heat exchanger 26 and then is supplied as cooling to the vehicle interior through the outlet 33.

(Dehumidifying operation)
Next, the dehumidifying operation of the vehicle air conditioner 10 will be described. FIG. 7 is an explanatory diagram for explaining the dehumidifying operation of the vehicle air conditioner 10.
As shown in FIG. 7, during the dehumidifying operation, the air mix door 25 is set to the heating position, and the heating valve 44 and the dehumidifying valve 48 are opened. During the dehumidifying operation, the bypass valve 52 is closed.

In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 41 heats the conditioned air in the duct 21 by heat radiation in the indoor heat exchanger 26.
And among the refrigerant | coolants which passed the indoor heat exchanger 26, one refrigerant | coolant distribute | circulates toward the outdoor heat exchanger 43, and the other refrigerant | coolant flows in into the dehumidification flow path 57. FIG.

Specifically, one refrigerant, after being expanded by the heating expansion valve 42, absorbs heat from the outdoor atmosphere in the outdoor heat exchanger 43, as in the heating operation described above.
The other refrigerant flows into the cooling flow channel 55 through the dehumidification flow channel 57 and then is expanded by the cooling expansion valve 46 and then absorbs heat in the evaporator 24 in the same manner as the cooling operation described above.
Thereafter, the one refrigerant and the other refrigerant merge at the junction 59 and then flow into the accumulator 47, and only the gas-phase refrigerant is sucked into the compressor 41.

Next, the flow of conditioned air during the above-described dehumidifying operation will be described.
The conditioned air flowing in the duct 21 is cooled when passing through the evaporator 24. At this time, the conditioned air passing through the evaporator 24 is dehumidified by being cooled to a dew point or lower. Thereafter, the dehumidified conditioned air passes through the heating path, and then is supplied as dehumidifying heating through the blowout port 33 into the vehicle interior.

(Defrosting operation)
Next, the defrosting operation will be described. FIG. 8 is an explanatory diagram for explaining the defrosting operation of the vehicle air conditioner 10, in which (A) shows the hot gas operation and (B) shows the reverse defrosting operation.
In the defrosting operation of the present embodiment, at least one of a so-called hot gas operation and a reverse defrosting operation can be performed.

(Hot gas operation)
In the hot gas operation shown in FIG. 8 (A), the heating expansion valve 42 is opened with a large diameter, and the refrigerant (hot gas) compressed by the compressor 41 flows into the outdoor heat exchanger 43 as it is. This is different from the heating operation described above.

  Specifically, the high-temperature and high-pressure refrigerant compressed by the compressor 41 heats the conditioned air in the duct 21 by heat radiation in the indoor heat exchanger 26. The refrigerant flowing out of the indoor heat exchanger 26 passes through the heating expansion valve 42 and flows into the outdoor heat exchanger 43. At this time, since the heating expansion valve 42 is opened with a large diameter, the refrigerant does not expand by the heating expansion valve 42 and flows into the outdoor heat exchanger 43 with a high pressure and a high temperature. Thereby, since the refrigerant dissipates heat in the outdoor heat exchanger 43, the outdoor heat exchanger 43 can be defrosted. In addition, the refrigerant | coolant which passed the outdoor heat exchanger 43 returns to the compressor 41 through the distribution channel similar to the heating operation mentioned above.

  Next, in the hot gas operation described above, the conditioned air is heated by the indoor heat exchanger 26 in the heating path and then supplied to the vehicle interior, as in the heating operation described above. In the hot gas operation, the conditioned air taken into the duct 21 is preferably outside air.

(Reverse defrosting operation)
The reverse defrosting operation shown in FIG. 8B is different from the above-described cooling operation in that the air mix door 25 is set to the heating position.
Specifically, the high-temperature and high-pressure refrigerant discharged from the compressor 41 passes through the indoor heat exchanger 26 and the bypass valve 52 and is radiated to the outdoor atmosphere in the outdoor heat exchanger 43. Then, when the refrigerant dissipates heat in the outdoor heat exchanger 43, the outdoor heat exchanger 43 is defrosted. Thereafter, the refrigerant is expanded by the cooling expansion valve 46, and then the conditioned air in the duct 21 is cooled by the heat absorption in the evaporator 24. Note that the refrigerant that has passed through the evaporator 24 returns to the compressor 41 through the same flow path as in the cooling operation described above.

  The flow of conditioned air in the reverse defrosting operation described above is the same as the flow of conditioned air in the hot gas operation described above. That is, the conditioned air flowing through the duct 21 is heated by the indoor heat exchanger 26 in the heating path and then supplied into the vehicle interior.

  Here, as shown in FIGS. 2 and 3, in the present embodiment, the PTC thermistor 62 attached to the accumulator 47 is operated during the defrosting operation described above. Then, the liquid phase refrigerant stored in the accumulator 47 is heated by the heat generated in the PTC thermistor 62. As a result, the liquid-phase refrigerant evaporates into a gas-phase refrigerant. The refrigerant that has become a gas phase flows into the bypass channel 88 from above the outer cylinder 83 in the accumulator 47. The refrigerant flowing into the bypass flow path 88 flows downward in the bypass flow path 88 and then flows into the inner cylinder 82. The gas-phase refrigerant that has flowed into the inner cylinder 82 flows out onto the refrigerant flow path 49 through the refrigerant outlet 72. Thereafter, the refrigerant is sucked into the compressor 41 and then subjected to the dehumidifying operation described above.

As described above, in the present embodiment, during the defrosting operation, by operating the PTC thermistor 62, the flow rate of the gas-phase refrigerant flowing through the heat pump cycle 12 can be increased. Thereby, the amount of heat radiation in the outdoor heat exchanger 43 can be increased, and the defrosting operation can be performed effectively.
In particular, in the present embodiment, the PTC thermistor 62 is used as means for heating the refrigerant in the accumulator 47. According to this configuration, when the heating element 95 is overheated to a predetermined temperature (Curie temperature) due to, for example, a decrease in the liquid-phase refrigerant in the accumulator 47, the resistance value rapidly increases and the PTC thermistor 62 is supplied to the PTC thermistor 62. The current supply is automatically limited (OFF state). For this reason, it is possible to suppress idling of the accumulator 47 and the like without performing complicated power control as in the prior art. As a result, the defrosting operation can be performed easily and effectively.

In the present embodiment, since the wedge members 110 and 111 are interposed between the inner surface of the thermistor accommodating portion 92 and the electrode plate 96 of the PTC thermistor 62, the heating element 95 and each electrode plate 96, of the PTC thermistor 62 are provided. 97 can be firmly brought into close contact. Thereby, it is possible to suppress the electrode plates 96 and 97 from being separated from the heating element 95, and to ensure stable operation reliability over a long period of time.
In addition, since the wedge members 110 and 111 are arranged without a gap between the inner surface of the thermistor housing portion 92 and the electrode plates 96 and 97 of the PTC thermistor 62, the heat generated in the PTC thermistor 62 is transferred to the accumulator 47. It can be effectively transmitted to the refrigerant.

  In the present embodiment, the refrigerant stored in the case 61 can be effectively heated by forming the thermistor accommodating portion 92 that is recessed inward in the radial direction in the cylindrical portion 64 b of the case main body 64.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 9 is a longitudinal sectional view of an accumulator 200 according to the second embodiment. This embodiment is different from the first embodiment described above in that the PTC thermistor 62 is caulked and fixed to the thermistor housing 213. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
In the case 210 of the accumulator 200 shown in FIG. 9, the case main body 215 has a cylindrical portion 211 and a bottom member 212 that closes the lower end opening of the cylindrical portion 211.

  The bottom member 212 is provided with a thermistor accommodating portion 213 that is recessed upward. The thermistor accommodating portion 213 is formed at a position that does not overlap with the communication pipe 81 described above when viewed from the axial direction. The thermistor accommodating portion 213 is open on the lower surface of the bottom member 212.

  The PTC thermistor 62 is inserted into the thermistor housing part 213 from below. The PTC thermistor 62 is caulked and fixed by side wall portions (caulking portions) 213 a that face each other in the stacking direction in the thermistor housing portion 213. As a result, the PTC thermistor 62 is held in the thermistor housing 213.

According to the present embodiment, since the PTC thermistor 62 is caulked and fixed in the stacking direction in the thermistor housing portion 213, the heating element 95 of the PTC thermistor 62 and the electrode plates 96 and 97 can be firmly brought into close contact with each other. . Thereby, it is possible to suppress the electrode plates 96 and 97 from being separated from the heating element 95, and to ensure stable operation reliability over a long period of time.
Further, the heat generated in the PTC thermistor 62 is effectively transferred to the refrigerant in the accumulator 200 by bringing the inner surface of the side wall portion 213a in the thermistor housing portion 213 into contact with the electrode plates 96 and 97 of the PTC thermistor 62. Can do.
Furthermore, in this embodiment, by using the side wall part 213a of the thermistor accommodating part 213 as a caulking part, the number of parts can be reduced compared with the case where the wedge members 110 and 111 are separately used.

  Note that a thermistor housing 252 may be provided on the lid member 251 as in the accumulator 250 shown in FIG. Even in this case, the PTC thermistor 62 is caulked and fixed by the side wall portion 252a facing the PTC thermistor 62 in the stacking direction in the thermistor accommodating portion 252, and the same operational effects as those of the second embodiment described above can be obtained. be able to.

(Third embodiment)
Next, a third embodiment of the present invention will be described. FIG. 11 is a cross-sectional view of an accumulator 300 according to the third embodiment. The present embodiment is different from the above-described embodiment in that the PTC thermistor 62 is fixed to the case 301 from below.
In the case 301 of the accumulator 300 shown in FIG. 11, a fixing member 310 for fixing the PTC thermistor 62 to the bottom wall 303 is provided on the bottom wall 303 of the case main body 302.

  The fixing member 310 is formed in a disk shape having an outer diameter equivalent to that of the bottom wall portion 303 in a plan view viewed from the axial direction. The fixing member 310 is formed with a thermistor accommodating portion 311 that is recessed downward. A PTC thermistor 62 is accommodated in the thermistor accommodating portion 311 in a state where the stacking direction is directed in the axial direction. The fixing member 310 covers the bottom wall portion 303 from below and is fixed to the bottom wall portion 303 with the PTC thermistor 62 sandwiched between the bottom wall portion 303 in the axial direction.

  According to the present embodiment, the same effects as the above-described embodiment can be obtained, and the PTC thermistor 62 can be easily attached to the case 301 by attaching the PTC thermistor 62 from the outside of the case main body 302.

The technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. In other words, the configuration described in the above-described embodiment is merely an example, and can be changed as appropriate.
For example, in the above-described embodiment, an electric vehicle has been described as an example of a vehicle that does not include an engine. However, the present invention is not limited to this, and the vehicle air conditioner 10 of the present invention may be employed in a fuel cell vehicle. Absent. Moreover, you may employ | adopt the vehicle air conditioner 10 of this invention for the vehicle which comprises an engine.

In the above-described embodiment, the configuration in which the PTC thermistor 62 is sandwiched in the stacking direction by the wedge members 110 and 111, the caulking portion, and the fixing member 310 is described. However, the configuration is not limited to this, and the configuration in which the PTC thermistor 62 heats the refrigerant. If it is okay.
In this case, the PTC thermistor 62 may be held not only in the stacking direction but in an in-plane direction orthogonal to the stacking direction.
In the embodiment described above, the case where one PTC thermistor 62 is provided has been described. However, the present invention is not limited to this, and a configuration in which a plurality of PTC thermistors 62 are provided may be used.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by the known component, and you may combine each modification mentioned above suitably.

DESCRIPTION OF SYMBOLS 10 ... Vehicle air conditioner 26 ... Indoor heat exchanger 41 ... Compressor 43 ... Outdoor heat exchanger 47, 200, 250, 300 ... Accumulator 61, 210, 301 ... Case 62 ... PTC thermistor 64b ... Cylindrical part 92, 213, 252 , 311 ... thermistor housing part 95 ... heating element 96 ... first electrode plate (electrode plate)
97 ... Second electrode plate (electrode plate)
110 ... 1st wedge member (wedge member)
111 ... second wedge member (wedge member)
213a, 252a ... Side wall part (crimping part)
303 ... bottom wall

Claims (5)

A compressor that compresses and discharges the refrigerant;
An indoor heat exchanger that radiates heat by the refrigerant discharged from the compressor;
An outdoor heat exchanger that exchanges heat between the refrigerant discharged from the indoor heat exchanger and the outdoor atmosphere;
An accumulator that is disposed upstream of the compressor in the flow direction of the refrigerant, separates the gas-liquid of the refrigerant, and circulates the gas-phase refrigerant toward the compressor;
A PTC thermistor provided in the accumulator;
During the defrosting operation for performing defrosting of the outdoor heat exchanger, the refrigerant discharged from the compressor is radiated by the outdoor heat exchanger, and the refrigerant in the accumulator is heated by the PTC thermistor. A vehicle air conditioner. The accumulator is
A case for containing a refrigerant;
A thermistor accommodating portion that is provided in the case and accommodates the PTC thermistor;
The PTC thermistor is
A heating element;
A pair of electrode plates sandwiching the heating element,
2. The vehicle air conditioner according to claim 1, wherein a wedge member is interposed between an inner surface of the thermistor housing portion and the electrode plate in the thermistor housing portion. The accumulator is
A case for containing a refrigerant;
A thermistor accommodating portion that is provided in the case and accommodates the PTC thermistor;
The PTC thermistor is
A heating element;
A pair of electrode plates sandwiching the heating element,
3. The vehicle air conditioner according to claim 1, wherein the thermistor housing portion includes a caulking portion that sandwiches the PTC thermistor in a stacking direction of the heating element and the electrode plate. The accumulator is
A bottomed cylindrical case for accommodating the refrigerant;
The thermistor accommodating part which accommodates the said PTC thermistor while being formed in the cylinder part of the said case, and being depressed inside the radial direction of the said cylinder part, The any one of Claims 1-3 characterized by the above-mentioned. The vehicle air conditioner according to claim 1. The accumulator includes a bottomed cylindrical case that contains a refrigerant,
The vehicular air conditioner according to any one of claims 1 to 4, wherein the PTC thermistor is fixed to a bottom wall portion of the case.

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