JP2019018705A - Air conditioner for vehicle - Google Patents

Abstract

To provide an air conditioner for vehicle that is fitted to a heater by simple means and can improve efficiency of heat conduction from the heater to a refrigerant.SOLUTION: A refrigerant flow passage 64 provided with a refrigerant heating heater 65 for heating a refrigerant is connected to refrigerant piping. The refrigerant heating heater 65 is pressed to contact the refrigerant flow passage 64. Specifically, the refrigerant heating heater 65 is held by the refrigerant flow passage 64 from both sides and the refrigerant flow passage 64 is fixed by caulking at a position shown by an arrow 68. The refrigerant heating heater 65 is held by the refrigerant flow passage 64 from both sides and housed in a housing. The housing is fixed with a bolt, and then the refrigerant heating heater 65 is pressed to contact the refrigerant flow passage 64.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle air conditioner.

As described in Patent Document 1, a technique using a heat pump as a vehicle air conditioner is known.
A heat pump is a device that evaporates refrigerant in an outdoor heat exchanger during heating operation or the like, and pumps up outdoor heat. For this reason, frost may adhere to the outdoor heat exchanger and heat transfer may be hindered, resulting in a problem that the performance gradually decreases. For this reason, the defrosting operation is periodically performed to remove frost attached to the outdoor heat exchanger.
On the other hand, when the outside air temperature is low, there is a limit to collecting external heat by the outdoor heat exchanger, so that a heater is provided in the refrigerant pipe to heat the refrigerant.

JP 2017-74833 A

However, when a heater is attached to the refrigerant pipe, it is desired that the heater be attached by simple means. It is also desirable to improve the efficiency of heat transfer from the heater to the refrigerant.
Then, the subject of this invention is providing the vehicle air conditioner which can attach a heater with a simple means and can improve the heat-transfer efficiency from a heater to a refrigerant | coolant.

  The present invention is an air conditioner for a vehicle that connects a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve with a refrigerant pipe to perform air conditioning in a vehicle interior, and the refrigerant pipe is provided in a predetermined place with a refrigerant. A refrigerant flow path provided with a refrigerant heater for heating is installed, and the refrigerant heater is pressure-bonded to the refrigerant flow path.

  ADVANTAGE OF THE INVENTION According to this invention, a heater can be attached by a simple means and the vehicle air conditioner which can improve the heat transfer efficiency from a heater to a refrigerant | coolant can be provided.

It is a circuit diagram of the refrigerant circuit of the air conditioner for vehicles concerning Embodiment 1 of the present invention. It is the side view (a) of the refrigerant | coolant flow path heater apparatus arrange | positioned at the refrigerant | coolant piping of the vehicle air conditioner which concerns on Embodiment 1 of this invention, and AA sectional drawing (b) of (a). It is a longitudinal cross-sectional view of the refrigerant heater of the vehicle air conditioner which concerns on Embodiment 1 of this invention. The top view (a) explaining attachment of the refrigerant heater to the refrigerant passage heater device of the air-conditioner for vehicles concerning Embodiment 1 of the present invention, and the side explaining attachment of two refrigerant passages to a connecting part It is (c) and (d) which are figures BB sectional drawing of (b) and (b). It is drawing which concerns on the modification of the vehicle air conditioner which concerns on Embodiment 1 of this invention, and is a perspective view (a) of a refrigerant | coolant flow path heater apparatus, and CC sectional drawing (b) of (a). It is a longitudinal cross-sectional view which shows the refrigerant | coolant flow path heater apparatus of the vehicle air conditioner which concerns on Embodiment 2 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is a system diagram of a refrigerant circuit of a vehicle air conditioner 10 according to the present embodiment. The vehicle air conditioner 10 is an apparatus that air-conditions the passenger compartment. Below, the structure and operation | movement of each part of the vehicle air conditioner 10 are outlined in the example in the case where the vehicle air conditioner 10 performs dehumidification operation and heating operation.

The vehicle air conditioner 10 includes an air conditioning unit 11, a heat pump cycle 12, and a control unit (not shown). The devices that mainly constitute the heat pump cycle 12 are connected by a refrigerant pipe 20.
The air conditioning unit 11 is provided with an air conditioning unit case 51, a blower 53, an air mix door 54, an evaporator 26, and an indoor heat exchanger 22. Air-conditioned air circulates inside the air-conditioning unit case 51.

  The air conditioning unit case 51 has a door 52 at one end and an air outlet (not shown) at the other end. The blower 53, the evaporator 26, the air mix door 54, and the indoor heat exchanger 22 are arranged in that order from the upstream to the downstream in the flow direction of the conditioned air in the duct. The flow direction of the conditioned air is the direction from the door 52 to the air outlet.

The door 52 switches between inside air and outside air. The opening degree of the door 52 is adjusted by control by the control unit. Therefore, the flow rate of the air flowing into the air conditioning unit case 51 is adjusted. The taken-in air is guided into the air conditioning unit case 51 as conditioned air. From the air outlet, the conditioned air flowing through the air conditioning unit case 51 is discharged into the room.
The blower 53 sends the conditioned air taken in from the door 52 downstream, that is, toward the evaporator 26. The blower 53 is driven according to the drive voltage applied from the control unit. The delivery amount of the conditioned air is controlled by the power supplied by the drive voltage.

  The evaporator 26 performs heat exchange between the low-temperature and low-pressure refrigerant that has flowed in through the expansion valve B25 (described later) and the conditioned air taken into the air-conditioning unit case 51. The heat of the conditioned air passing through the evaporator 26 is absorbed by the refrigerant when the refrigerant evaporates. Thereby, the conditioned air passing through the evaporator 26 is cooled, the evaporator 26 is condensed, and the ambient humidity is lowered. The cooled conditioned air is sent to the indoor heat exchanger 22 via the air mix door 54 or so as to bypass the indoor heat exchanger 22. In the following description, the gas phase refrigerant may be referred to as a gas refrigerant, and the liquid phase refrigerant may be referred to as a liquid refrigerant.

  A temperature sensor (not shown) is installed in the vicinity of the evaporator 26. The temperature sensor installed in the evaporator 26 detects the temperature of the evaporator 26 and outputs a detection signal indicating the detected temperature to the control unit. The detection signal from the temperature sensor is used to determine the air conditioning load according to the temperature of the evaporator 26 in the control unit as will be described later. As the air conditioning load, for example, the rotation speed of the compressor 21 is controlled.

  The air mix door 54 is a heating position that opens a ventilation path from the evaporator 26 to the indoor heat exchanger 22 in the air conditioning unit case 51, and cooling that opens a ventilation path that bypasses the indoor heat exchanger 22 from the evaporator 26. It can be rotated between positions. The air mix door 54 in the cooling position blocks the ventilation path toward the indoor heat exchanger 22. The rotation position of the air mix door 54 is controlled between the heating position and the cooling position by the control unit. By this control, whether the conditioned air delivered from the evaporator 26 is allowed to pass through the indoor heat exchanger 22 or the flow rate of the conditioned air passing through the indoor heat exchanger 22 and the air bypassing the indoor heat exchanger 22 is determined. The flow rate ratio with the flow rate of the conditioned air discharged into the room from the air outlet is adjusted. In the dehumidifying operation, the rotation position of the air mix door 54 is controlled to the heating position. Therefore, the ventilation path from the evaporator 26 to the indoor heat exchanger 22 is opened, and the heat of the refrigerant flowing into the indoor heat exchanger 22 is radiated. In the following description, controlling the rotation position of the air mix door 54 to the heating position may be referred to as opening the air mix door 54. Further, controlling the rotation position to the cooling position may be referred to as closing the air mix door 54.

  The indoor heat exchanger 22 performs heat exchange between the high-temperature and high-pressure refrigerant flowing from the compressor 21 and the air passing through the heat exchanger 26. In the indoor heat exchanger 22, the heat of the flowing refrigerant is radiated to the conditioned air having a lower temperature. Therefore, the conditioned air passing through the indoor heat exchanger 22 is heated. The conditioned air that has passed through the indoor heat exchanger 22 is blown out from the air outlet.

  Next, the configuration and function of the heat pump cycle 12 will be described mainly using the case where the operation mode is the dehumidifying operation as an example. The heat pump cycle 12 includes an evaporator 26 and an indoor heat exchanger 22, an expansion valve A 23, an outdoor heat exchanger 24, an expansion valve B 25, an accumulator 28, and a compressor 21. The components necessary for the dehumidifying operation are the indoor heat exchanger 22, the expansion valve A23, the outdoor heat exchanger 24, the expansion valve B25, the evaporator 26, the accumulator 28, and the compressor 21, and in the dehumidifying operation, the refrigerants are in that order. Circulates.

  The compressor 21 is driven by a motor (not shown), sucks the gas refrigerant flowing in from the accumulator 28, and compresses the sucked gas refrigerant. The compressor 21 sends the high-temperature and high-pressure refrigerant generated by the compression to the indoor heat exchanger 22. The indoor heat exchanger 22 performs heat exchange between the air in the air conditioning unit case 51 and the refrigerant. The motor is driven at a rotational speed corresponding to the electric power supplied from the control unit.

  The expansion valve A23 expands the refrigerant flowing from the indoor heat exchanger 22 by reducing the pressure. The opening degree of the expansion valve A23 is controlled by the control unit. The gas-liquid two-phase spray refrigerant having a medium temperature and a medium pressure generated by the decompression is sent to the outdoor heat exchanger 24. Medium temperature and medium pressure are called intermediate temperature and intermediate pressure, respectively.

  The outdoor heat exchanger 24 is disposed outside the vehicle compartment. The outdoor heat exchanger 24 performs heat exchange between the refrigerant flowing from the expansion valve A23 and the outside air. When the temperature of the refrigerant in the outdoor heat exchanger 24 is lower than the outside air temperature, the refrigerant that flows in absorbs heat of the outside air. Thereby, the temperature of the refrigerant rises. When the temperature of the refrigerant in the outdoor heat exchanger 24 is higher than the outside air temperature, the refrigerant that flows in radiates heat to the outside air. Thereby, the refrigerant is cooled. The refrigerant that has undergone heat exchange is sent to the evaporator 26 via the expansion valve B25.

  A temperature sensor (not shown) is installed in the vicinity of the outdoor heat exchanger 24. The temperature sensor installed in the vicinity of the outdoor heat exchanger 24 detects the outside air temperature, and outputs a detection signal indicating the detected outside air temperature to the control unit. The detection signal from the temperature sensor is used to determine the air conditioning load in accordance with the outside air temperature in the control unit. As parameters of the air conditioning load that depends on the outside air temperature, the control unit controls, for example, the rotation speed of the compressor 21, the opening / closing and opening of various valves in the refrigerant flow path in each operation mode, and the like.

The branch part 33 has a configuration capable of branching the refrigerant flowing from the outdoor heat exchanger 24 to the electromagnetic valve 43 and the expansion valve B25. The electromagnetic valve 43 opens and closes the flow path under the control of the control unit. In the dehumidifying operation, the electromagnetic valve 43 blocks the refrigerant from the outdoor heat exchanger 24 by closing the flow path.
On the other hand, the expansion valve B25 expands the refrigerant flowing from the outdoor heat exchanger 24 by reducing the pressure. The opening degree of the expansion valve B25 is controlled by the control unit. The low-temperature and low-pressure refrigerant generated by the decompression is sent to the evaporator 26.

  The switching unit 34 switches between the refrigerant flowing from the evaporator 26 and the refrigerant flowing from the electromagnetic valve 43. The refrigerant that has passed through the switching unit 34 is sent to the accumulator 28. However, in the dehumidifying operation, the refrigerant does not flow from the electromagnetic valve 43 into the switching unit 34. The refrigerant heater 65 will be described later.

  The accumulator 28 separates the gas refrigerant and the liquid refrigerant from the gas-liquid two-phase refrigerant flowing from the switching unit 34, and the liquid refrigerant remains. The gas refrigerant separated without remaining in the accumulator 28 is supplied to the compressor 21.

Next, the function of the heat pump cycle 12 will be described taking the case where the operation mode is the heating operation as an example. In the following description, the difference from the case where the operation mode is the dehumidifying operation will be mainly described.
In the heating operation, the refrigerant circulates in the order of the expansion valve A23, the outdoor heat exchanger 24, the accumulator 28, and the compressor 21 as components.
In the heating operation, the expansion valve A23 opens the flow path under the control of the control unit. The expansion valve A23 expands the refrigerant flowing from the indoor heat exchanger 22 by reducing the pressure. The low-temperature and low-pressure refrigerant generated by the decompression is sent to the outdoor heat exchanger 24.

  In the outdoor heat exchanger 24, the low-temperature refrigerant flowing in from the expansion valve A23 absorbs heat of outdoor air having a higher temperature. Thereby, the refrigerant is heated. In the heating operation, the electromagnetic valve 43 is controlled to open the flow path. On the other hand, the expansion valve B25 closes the flow path under the control of the control unit. Therefore, the refrigerant that has absorbed heat in the outdoor heat exchanger 24 is sent to the accumulator 28 via the branch portion 33, the electromagnetic valve 43, and the switching portion 34. Further, the control unit adjusts the position of the air mix door 54 so that the heat exchanger 22 is ventilated.

Therefore, while the temperature of the indoor heat exchanger 22 increases due to the circulation of the refrigerant, the temperature of the evaporator 26 does not decrease. The conditioned air that has flowed into the air conditioning unit case 51 is not cooled by the evaporator 26, but is heated and discharged in the process of passing through the indoor heat exchanger 22. The discharged conditioned air is supplied as heating.
Heretofore, the configuration and operation of the vehicle air conditioner 10 have been described with respect to an example in which the dehumidifying operation and the heating operation are performed. Here, illustration and description of the configuration necessary for the cooling operation are omitted.

Incidentally, for example, a refrigerant heater 65 for heating the refrigerant is disposed in the refrigerant pipe 62 between the switching unit 34 and the accumulator 28. The refrigerant heater 65 is controlled by the control unit to heat the refrigerant when the outside air temperature is low and sufficient heat cannot be collected by the outdoor heat exchanger 24. The refrigerant heater 65 is attached to the refrigerant flow path heater device 63 and is disposed in the refrigerant pipe 62.
Below, the means for attaching the refrigerant | coolant heater 65 by providing the refrigerant | coolant flow path heater apparatus 63 in the refrigerant | coolant piping 62 between the switching part 34 and the accumulator 28 is demonstrated concretely.

  FIG. 2 is a side view (a) of the refrigerant flow path heater device 63 disposed in the refrigerant pipe 62, and a cross-sectional view (b) taken along the line AA in (a). Both ends of the refrigerant flow path heater device 63 are connected to the refrigerant pipes 62 on the switching unit 34 side and the accumulator 28 side, respectively. The refrigerant channel heater device 63 includes two refrigerant channels 64. The refrigerant flow path 64 is a long and long refrigerant passage having a rectangular cross section, for example. In each refrigerant flow path 64, a plurality (five in the example of FIG. 2) of divided flow paths 64a are provided, and the refrigerant flows therethrough. A refrigerant heater 65 is provided between the two refrigerant channels 64. The refrigerant heater 65 has a long flat plate shape, and the width in the short direction is substantially the same as that of the refrigerant flow path 64. As the refrigerant heater 65, for example, a PTC (Positive Temperature Coefficient) heater is used.

  FIG. 3 is a longitudinal sectional view of the refrigerant heater 65. The refrigerant heater 65 includes, for example, an aluminum case 81 on the outermost periphery. An insulating film 82 is formed on the inner peripheral surface of the case 81. A PTC element 84 having electrodes 83 provided on both sides is accommodated in the insulating film 82.

At both ends of such a refrigerant flow path heater device 63, connecting portions 66 for connecting the refrigerant flow path heater device 63 to the refrigerant pipe 62 are provided. The connecting portion 66 is provided with a round hole-like connecting portion 66a for connecting the refrigerant pipe 62, and a bolt hole 66b for fastening a bolt with a flange portion (not shown) of the refrigerant pipe 62. By connecting the refrigerant flow path heater device 63 and the refrigerant pipe 62 via the connecting portion 66, the refrigerant flows between the refrigerant flow path 64 and the refrigerant pipe 62.
Further, a projection 64c extends toward the inside of the passage 64a on the inner wall 64b on the refrigerant heater 65 side of each divided flow path 64a.

  Next, the assembly structure of the refrigerant flow path heater device 63 will be described. 4A is a top view for explaining the attachment of the refrigerant heater 65 to the refrigerant passage heater device 63, FIG. 4B is a side view for explaining the attachment of the two refrigerant passages 64 to the connecting portion 66, and FIG. It is BB sectional drawing (c) (d) of b).

  As shown in FIG. 4 (b), both ends 64d of the two refrigerant flow paths 64 are inserted into insertion holes 66c formed on the side opposite to the connection part 66a of the connecting part 66, respectively. The path 64 and the connecting portion 66 are joined by brazing, for example. At this time, as shown in FIG. 4C, a space 67 in which the refrigerant heater 65 can be accommodated is formed between the two refrigerant flow paths 64.

And as shown in FIG.4 (c), the refrigerant | coolant heater 65 is accommodated in the space 67 from the top. Then, as shown in FIGS. 4A and 4D, the two refrigerant flow paths 64 are pressurized from a plurality of locations outside the respective side portions of the two refrigerant flow paths 64 so that the refrigerant flow paths 64 are changed. Caulking (arrow 68 illustrates the caulking position). Thereby, the refrigerant heater 65 is caulked and fixed to the two refrigerant flow paths 64. Therefore, the refrigerant heater 65 and the two refrigerant flow paths 64 are pressure-bonded.
Thus, since the refrigerant heater 65 is fixed by caulking to the two refrigerant channels 64, the upper part and the lower part of the two refrigerant channels 64 at the caulking position 68 are somewhat raised by deformation.

FIG. 5 is a modification of the present embodiment. (A) is a perspective view of the refrigerant | coolant flow path heater apparatus 63, (b) is CC sectional drawing of (a). In this modification, only the refrigerant flow path heater device 63 is different from those shown in FIGS. In FIG. 5, members similar to those of the refrigerant flow path heater device 63 of FIGS. 2 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 5 is different from the above-described embodiment in that the refrigerant flow path 64 and the refrigerant heater 65 are increased one by one, and another structure in which the refrigerant heater 65 is sandwiched between the two refrigerant flow paths 64 is increased. It is. The structure in which the refrigerant heater 65 is sandwiched between the two refrigerant channels 64 may be further increased.

According to the present embodiment, since the refrigerant heater 65 is fixed to the two refrigerant flow paths 64 by pressure bonding, the refrigerant heater 65 can be attached to the two refrigerant flow paths 64 by simple means. The heat transfer efficiency from the heater 65 to the refrigerant can be improved.
Further, since caulking is used as a means for pressure-bonding the refrigerant heater 65 to the refrigerant flow path 64, the refrigerant heater 65 can be attached to the refrigerant flow path 64 by simple means.

Further, in the refrigerant flow path 64, a protrusion 64c extends toward the inside of the passage 64a on the inner wall 64b on the refrigerant heater 65 side of each divided flow path 64a. Therefore, the heat transfer efficiency of the heat generated by the refrigerant heater 65 to the refrigerant flowing through each divided flow path 64a can be increased.
Further, the refrigerant passage heater device 63 can be easily attached to the refrigerant pipe 62 by the connecting portion 66 provided at the end of the refrigerant heater 65 and the refrigerant passage 64.

[Embodiment 2]
In the description of the present embodiment, the same reference numerals as those in the first embodiment are used for members and the like similar to those in the first embodiment, and detailed description thereof is omitted.
The overall configuration of the vehicle air conditioner 10 of the present embodiment is the same as that of the first embodiment. The present embodiment differs from the first embodiment in that the means for pressure-bonding the refrigerant heater 65 to the refrigerant flow path 64 is different in the modification shown in FIG.

  FIG. 6 is a longitudinal sectional view showing the refrigerant flow path heater device 63 in the present embodiment. That is, each refrigerant heater 65 is sandwiched between the refrigerant flow paths 64 from both sides and stored in the casing 71. The casing 71 includes two casings 71a and 71a, and by combining the two casings 71a and 71a, the refrigerant flow path heater device 63 can be accommodated therein. This interior matches the shape of the refrigerant flow path heater device 63, but is slightly smaller than the volume of the refrigerant flow path heater device 63. The refrigerant flow path heater device 63 is housed in such a casing 71, and the flange portions 72b and 72b of the two casings 71a and 71a are fastened with bolts 72, respectively. Thus, the refrigerant heater 64 can be pressure-bonded to the refrigerant flow path 64 by tightening the refrigerant flow path 64.

According to the present embodiment, since the refrigerant heater 65 is fixed to the two refrigerant flow paths 64 by pressure bonding, the refrigerant heater 65 can be attached to the two refrigerant flow paths 64 by simple means. The heat transfer efficiency from the heater 65 to the refrigerant can be improved.
In addition, since bolt fastening is used as means for pressure-bonding the refrigerant heater 65 to the refrigerant flow path 64, the refrigerant heater 65 can be attached to the refrigerant flow path 64 by simple means.

Further, as in the first embodiment, in the refrigerant flow path 64, a protrusion 64c extends toward the inside of the passage 64a on the inner wall 64b on the refrigerant heater 65 side of each passage 64a. Therefore, the heat transfer efficiency of the heat generated by the refrigerant heater 65 to the refrigerant flowing through each passage 64a can be increased.
Further, similarly to the first embodiment, the refrigerant passage heater device 63 can be easily attached to the refrigerant pipe 62 by the connecting portion 66 provided at the end of the refrigerant heater 65 and the refrigerant passage 64.

  In each embodiment, the refrigerant flow path heater device 63, that is, the refrigerant heater 65 can be provided in various paths of the refrigerant pipe 20 as long as the refrigerant can be heated.

DESCRIPTION OF SYMBOLS 10 Vehicle air conditioner 21 Compressor 22 Indoor heat exchanger 23 Expansion valve A
24 Outdoor heat exchanger 25 Expansion valve B
62 Refrigerant piping 64 Refrigerant flow path 64b Inner wall 64c Protrusion 65 Refrigerant heater 66 Linking portions 71, 71a Housing 72 Bolt

Claims (5)

A vehicle air conditioner that connects a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve with a refrigerant pipe to perform air conditioning in a vehicle interior,
A refrigerant passage provided with a refrigerant heater for heating the refrigerant is connected to the refrigerant pipe at a predetermined location,
The vehicle air conditioner, wherein the refrigerant heater is pressure-bonded to the refrigerant flow path.   The said refrigerant heater is crimped | bonded to the said refrigerant flow path by the said refrigerant | coolant heater being pinched | interposed by the said refrigerant flow path from both sides, and fixing the said refrigerant flow path. Vehicle air conditioner.   The refrigerant heater is sandwiched between the refrigerant flow paths from both sides and housed in a casing, and the casing is bolted to fix the refrigerant heater to the refrigerant flow path. The vehicle air conditioner according to claim 1.   The vehicular air conditioning apparatus according to any one of claims 1 to 3, wherein a protrusion extending from an inner wall of the refrigerant flow path is provided in the refrigerant flow path in which the refrigerant heater is provided. .   The vehicle according to any one of claims 1 to 4, wherein a connecting portion that connects the refrigerant pipe to the refrigerant flow path is provided at both ends of the refrigerant flow path in the flow direction of the refrigerant. Air conditioner.

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