JP2013159134A - Heat medium heating device, and vehicular air conditioner including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat medium heating device capable of absorbing a thermal expansion difference between a flat heat exchanger tube side and a casing side, and thereby solving a problem wherein a stress exceeding a permitted value is applied, or a sealing performance is degraded, and to provide a vehicular air conditioner including the same.SOLUTION: A heat medium heating device 10 includes: a casing 11; a plurality of flat heat exchanger tubes 12; PTC (positive temperature coefficient) heaters each mounted between flat tube portions; and a heat exchanger pressing member 15 for pressing the flat heat exchanger tubes 12 and the PTC heaters against the inner surface of the casing 11 from one surface side to be fixed. Here, a means 28 to reduce a temperature difference between the temperature on a side of the flat heat exchanger tubes 12, and that of a fixation part 11D of the casing 11 at which the heat exchanger pressing member 15 is fastened and fixed.

Description

  The present invention relates to a heat medium heating device that heats a heat medium using a PTC heater, and a vehicle air conditioner including the heat medium heating device.

  In a vehicle air conditioner applied to an electric vehicle, a hybrid vehicle, or the like, a positive temperature coefficient thermistor element (hereinafter referred to as “Positive Temperature Coefficient”; hereinafter) A device using a PTC heater having a heat generating element as a PTC element) is known. In such a heat medium heating device, Patent Document 1 provides a plurality of partition walls that divide the inside of the housing having the heat medium inlet and outlet into a heating chamber and a heat medium circulation chamber, and is partitioned by the partition walls. In addition, a PTC element is inserted and installed on the heating chamber side so as to be in contact with the partition wall, and the PTC element sandwiches the partition wall and heats the heat medium flowing through the circulation chamber side.

  In Patent Document 2, a PTC heater is configured by providing an electrode plate, an insulating layer, and a heat transfer layer on both sides of a PTC element, and an inlet and an outlet for a heat medium are provided on both sides of the PTC heater. A heat medium heating device having a laminated structure in which a pair of heat medium flow boxes communicated with each other and a substrate housing box for housing a control board and a lid are provided on the outer surface side of the heat medium circulation box is disclosed. .

  However, in the thing of patent document 1, it is difficult to insert and install a PTC element in close contact between the partition walls serving as a heat transfer surface, and the contact thermal resistance between the partition walls and the PTC element increases, resulting in a decrease in heat transfer efficiency. was there. Moreover, in the thing of patent document 2, although the adhesiveness of a PTC heater and a heat carrier distribution box can be improved and contact thermal resistance can be reduced, since it is difficult to arrange | position a multilayer PTC heater, a plane area becomes large. At the same time, a heat medium distribution box and a dedicated substrate storage box are required, and there are limits to the reduction in size and weight and cost.

  Therefore, a heat medium heating device has been developed that uses a heat exchanger tube with a flat structure and forms a heat exchange element by alternately laminating flat heat exchanger tubes and PTC heaters in multiple layers and incorporating them into the casing. Has been. In the thing using the heat exchange element of such a laminated structure, in patent document 3, by applying a compressive load from the thickness direction with respect to the laminated flat heat exchanger tube, between flat heat exchanger tubes There is disclosed a structure in which a component to be cooled and a flat heat exchanger tube that are stacked on each other are brought into close contact with each other.

JP 2008-7106 A JP 2008-56044 A Japanese Patent No. 4100368

  As described above, in the case of using an element in which a flat heat exchanger tube and a PTC heater are laminated in multiple layers, the contact heat resistance between them can be reduced and the heat transfer efficiency can be improved by pressing and assembling them. . However, in order to sequentially laminate the flat heat exchanger tube and the PTC heater in multiple layers, the periphery of the communication holes in the inlet header portion and outlet header portion provided in the flat heat exchanger tube must be sealed with a sealing material such as an O-ring. In other words, it is necessary to press the inlet / outlet header portion to bring the sealing material into close contact therewith. For this reason, the inlet / outlet header portion is fastened and fixed together with the flat heat exchanger tube and the PTC heater via a pressing member. In this case, the pressing member is fastened and fixed to the casing side in which the element is incorporated.

  On the other hand, when the PTC heater is energized to heat the heat medium, a temperature difference is generated between the flat heat exchanger tube heated by the PTC heater and the portion where the casing pressing member is fastened and fixed. Due to the difference in thermal expansion due to this temperature difference, stress exceeding the allowable value is applied to the pressing member or casing, or the pressing force for pressing the sealing material into intimate contact becomes unstable, resulting in a decrease in sealing performance. There were problems such as sometimes.

  The present invention has been made in view of such circumstances, and absorbs a difference in thermal expansion between the flat heat exchanger tube side and the casing side, so that a stress exceeding an allowable value is applied or the sealing performance is lowered. It is an object of the present invention to provide a heat medium heating device and a vehicle air conditioner equipped with the heat medium heating device that can eliminate problems such as rusting and improve product quality and reliability.

In order to solve the above-described problems, the heat medium heating device of the present invention and the vehicle air conditioner including the same employ the following means.
That is, the heat medium heating device according to the present invention includes a casing provided with a heat medium outlet / inlet passage, and the heat medium that is communicated with the heat medium outlet / inlet passage of the casing and flows from the inlet header portion. A plurality of flat heat exchanger tubes that flow out from the outlet header after flowing through the flat tube portion, a PTC heater incorporated between the flat tube portions of the plurality of flat heat exchanger tubes stacked on each other, and the casing A heat exchange pressing member that is fixedly fastened to a fixed portion of the flat heat exchanger tube and presses the flat heat exchanger tube and the PTC heater against the inner surface of the casing from one surface side of the flat heat exchanger tube, The temperature of the flat heat exchanger tube side heated by the heater and the temperature of the fixed part of the casing to which the heat exchanger pressing member is fastened and fixed And it is provided with means for reducing the.

  According to the present invention, the plurality of flat heat exchanger tubes that are communicated with the heat medium outlet / inlet passage of the casing and flow out of the outlet header portion after the heat medium flowing in from the inlet header portion flows through the flat tube portion, and And a heat exchanger pressing member that presses the flat heat exchanger tube and the PTC heater against the fixed part of the casing against the inner surface of the casing from one side to the inner surface of the casing. In the medium heating device, there is provided means for reducing a temperature difference between the temperature on the flat heat exchanger tube side heated by the PTC heater and the temperature of the fixed portion of the casing to which the heat exchanger pressing member is fastened and fixed. Therefore, during the heating operation in which the PTC heater is energized to heat the heat medium, the temperature on the flat heat exchanger tube side heated by the PTC heater and the heat exchanger on the casing side By decreasing through the means for reducing the temperature difference between the temperature of the fixing portions that secure fastening members, can but to reduce the difference in thermal expansion generated at each site. Therefore, a difference in thermal expansion occurs due to the temperature difference between the temperature on the flat heat exchanger tube side and the temperature of the fixed part of the casing, and stress exceeding the allowable value is applied to the heat exchanger holder and the casing, or the flat heat exchanger tube To improve the product quality and reliability of the heat medium heating device by eliminating problems such as the pressure of the sealing material sealing the area around the communication hole in the inlet / outlet header section becomes unstable and the sealing performance decreases. Can do.

  Furthermore, in the heat medium heating device according to the present invention, in the above heat medium heating device, the means for reducing the temperature difference is provided in a fixed portion of the casing, and the heat medium that circulates in the flat heat exchanger tube. It is characterized by comprising a heat medium flow passage that circulates a part.

  According to the present invention, the means for reducing the temperature difference is provided in the fixed part of the casing, and is constituted by the heat medium flow passage that circulates a part of the heat medium that circulates in the flat heat exchanger tube. The temperature of the fixed part on the casing side is changed to the temperature on the flat heat exchanger tube side by circulating the heat medium flowing through the flat heat exchanger tube through the heat medium flow passage provided in the fixed part of the casing. Can be approached. Therefore, by reducing the difference in thermal expansion at both parts and preventing the occurrence of excessive thermal expansion difference, it is possible to reduce the stress applied to the heat exchanger holding member and the casing, and to It is possible to stabilize the pressing force of the sealing material sealing around the communication hole of the inlet header portion, and to prevent the sealing performance from being lowered.

  Furthermore, the heat medium heating device of the present invention is the heat medium heating device according to any one of the above, wherein the plurality of flat heat exchanger tubes are provided with a sealing material around communication holes of the inlet header portion and the outlet header portion. The sealing material is closely attached by the pressing force of the heat exchange pressing member to seal the communication hole.

  According to the present invention, the plurality of flat heat exchanger tubes are provided with a sealing material around the communication holes of the inlet header portion and the outlet header portion, and the sealing material is brought into close contact with the pressing force of the heat exchanger pressing member. Since the area around the communication hole is sealed, a plurality of flat heat exchange tubes are stacked around the communication hole around the communication hole in the inlet / outlet header of the flat heat exchange tube. The heat transfer efficiency between the flat heat exchanger tube and the PTC heater can be improved by facilitating the incorporation of the PTC heater with respect to the heat exchanger and pressing it with the heat exchanger pressing member, and the sealing performance by the sealing material can be improved. The temperature difference between the temperature of the flat heat exchanger tube and the temperature of the fixing part for fastening and fixing the heat exchanger pressing member can be reduced by means of reducing the temperature of both parts. By reducing the differential expansion, it can be pressed stably flat heat exchange tubes with a constant pressing force through the heat exchange holding member. Accordingly, it is possible to stabilize the tight seal around the communication hole by a sealing material such as an O-ring or a liquid gasket, and to ensure reliability for preventing the heat medium from leaking.

  Furthermore, the vehicle air conditioner according to the present invention is configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage. The heat medium heating device is any one of the above-described heat medium heating devices.

  According to the present invention, in a vehicle air conditioner configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage, the heat medium heating device Is one of the heat medium heating devices described above, the heat medium supplied to the radiator disposed in the air flow path is fixed to the temperature on the flat heat exchanger tube side and the heat exchanger presser member. It is possible to heat and supply by the above-mentioned heating medium heating device that eliminates the problems caused by the difference in thermal expansion due to the temperature difference from the temperature of the fixed part of the casing to be improved and improves the product quality and reliability. it can. Accordingly, it is possible to stabilize the heating performance of the vehicle air conditioner, eliminate the heat medium leakage, and improve the reliability of the vehicle air conditioner.

  According to the heat medium heating device of the present invention, during the heating operation in which the PTC heater is energized to heat the heat medium, the temperature on the flat heat exchanger tube side heated by the PTC heater and the heat exchanger pressing member on the casing side are fastened and fixed. By reducing the temperature difference between the fixed part and the temperature of the fixed part, the difference in thermal expansion occurring in each part can be reduced, so the temperature on the flat heat exchanger tube side and the casing A difference in thermal expansion occurs due to the temperature difference from the temperature of the fixed part of the tube, and stress exceeding the allowable value is applied to the heat exchanger retainer and casing, and the area around the communication hole in the outlet / inlet header of the flat heat exchanger tube is sealed. It is possible to solve the problems such as destabilization of the pressure of the sealing material being used and lowering the sealing performance, and to improve the product quality and reliability of the heat medium heating device.

  In addition, according to the vehicle air conditioner of the present invention, the heat medium supplied to the radiator disposed in the air flow passage is fixed to the temperature on the flat heat exchanger tube side and the casing for fixing the heat exchanger presser member. Because it can be heated and supplied by the above-mentioned heat medium heating device that eliminates the problems caused by the difference in thermal expansion due to the temperature difference from the temperature of the fixed part and improves the product quality and reliability. In addition to stabilizing the heating performance of the vehicle air conditioner, it is possible to eliminate leakage of the heat medium and improve the reliability of the vehicle air conditioner.

It is a schematic block diagram of the vehicle air conditioner provided with the heat-medium heating device which concerns on one Embodiment of this invention. It is a disassembled perspective view of the heat carrier heating apparatus shown in FIG. It is a top view of the state which removed the upper case of the heat carrier heating apparatus shown in FIG. It is a longitudinal cross-section equivalent view along the short side direction of the heat carrier heating apparatus shown in FIG. It is a longitudinal cross-sectional equivalent view of the site | part which clamp | tightens and fixes the heat exchanger pressing member of the heat carrier heating apparatus shown in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 shows a schematic configuration diagram of a vehicle air conditioner including a heat medium heating device according to an embodiment of the present invention.
The vehicle air conditioner 1 is provided with a casing 3 that forms an air flow passage 2 for taking outside air or vehicle interior air and adjusting the temperature thereof, and then guiding it to the vehicle interior.

  Inside the casing 3, the air or the passenger compartment air is sequentially sucked from the upstream side to the downstream side of the air flow passage 2 to increase the pressure, and the blower 4 pumps it to the downstream side. The flow rate ratio of the cooler 5 that cools the air, the radiator 6 that heats the air that has passed through the cooler 5, and the amount of air that passes through the radiator 6 and the amount of air that bypasses the radiator 6 An air mix damper 7 that adjusts the temperature of the temperature-controlled air by adjusting and air-mixing on the downstream side thereof is installed.

The downstream side of the casing 3 is connected to a plurality of outlets that blow out the temperature-controlled air into the vehicle compartment via an outlet mode switching damper and a duct (not shown).
The cooler 5 constitutes a refrigerant circuit together with a compressor, a condenser, an expansion valve, etc., not shown, and cools the air passing therethrough by evaporating the refrigerant adiabatically expanded by the expansion valve. . The radiator 6 forms a heat medium circulation circuit 10A together with the tank 8, the pump 9, and the heat medium heating device 10, and a high-temperature heat medium (for example, antifreeze liquid, water, etc.) heated by the heat medium heating device 10 is used. By circulating through the pump 9, the air passing therethrough is heated.

2 is an exploded perspective view of the heat medium heating device 10 shown in FIG. 1, FIG. 3 is a plan view of the state where the upper case is removed, and FIG. 4 is a short side of FIG. FIG. 5 shows a vertical cross-sectional equivalent view of a portion where the heat exchanger pressing member is fastened and fixed.
The heat medium heating device 10 includes a box-shaped casing 11, a heat exchange module 14 in which a plurality of (for example, three) flat heat exchanger tubes 12 and a plurality of sets of PTC heaters 13 are alternately stacked, A heat exchanger pressing member 15 for pressing and fixing the heat exchange module 14 to the inner bottom surface of the lower case 11A of the casing 11, and a PTC disposed on the heat exchanger pressing member 15 via a pair of spacer members 16 The control board 17 is configured to control the heater 13.

  The casing 11 is a box-shaped casing that is divided into an upper half and a lower half, and is positioned in the upper half (not shown) with respect to the lower case 11A located in the lower half. The upper case is configured to be integrated by being screwed and fixed via a plurality of screws. Then, in the internal space of the casing 11, the heat exchange module 14 including the flat heat exchange tube 12 and the PTC heater 13, the heat exchange pressing member 15, the pair of spacer members 16, the control board 17, and the like are accommodated and installed. It has become.

  On the lower surface of the lower case 11A, a heat medium inlet channel 11B for guiding the heat medium introduced into the three laminated flat heat exchanger tubes 12 and a heat medium flowing through the flat heat exchanger tubes 12 are derived. The heat medium outlet passage 11C is integrally formed so as to protrude downward, and the boss portion (fixed portion) 11D for fastening and fixing the heat exchanger pressing member 15 protrudes upward at four locations. Are integrally molded. The lower case 11A is formed of a resin material (for example, PPS) whose linear expansion coefficient is close to that of the aluminum alloy material constituting the flat heat exchanger tube 12 accommodated and installed in the internal space. Note that the upper case is also preferably formed of the same resin material as the lower case 11A.

  Further, a power harness hole and an LV harness hole (both not shown) are formed in the lower surface of the lower case 11A so as to penetrate through the distal end portions of the power harness 18 and the LV harness 19. The power harness 18 is for supplying power to the PTC heater 13 via the control board 17, and has two power harness terminal blocks provided on the control board 17 with the tip portion branched in a bifurcated shape. It can be screwed to 17A via a screw. Further, the LV harness 19 is for transmitting a control signal to the control board 17, and a tip end portion thereof is connectable to the control board 17.

  The control board 17 performs energization control for a plurality of sets of PTC heaters 13 based on a command from the host control unit (ECU), and includes a plurality of power transistors (heat-generating electrical components) 20 made of FETs, IGBTs, or the like. The control circuit 21 including the surface is mounted on the surface, and the energization state of the plurality of sets of PTC heaters 13 can be switched via the control circuit 21. The control board 17 has a heat penetration made of a highly thermally conductive material such as copper or aluminum so as to penetrate through both sides of the board corresponding to a portion where a plurality of power transistors 20 which are heat-generating electrical components are mounted. A portion (not shown) is provided.

  And the heat exchange module 14 is comprised by laminating | stacking the several flat heat exchanger tube 12 so that the said multiple sets of PTC heater 13 may be inserted | pinched from the both surfaces. The flat heat exchanger tube 12 is formed by superposing a pair of tube materials obtained by press-molding aluminum alloy thin plates. As shown in FIGS. 2 and 4, for example, three flat heat exchanger tubes 12 are used. The tubes 12 are laminated so as to be parallel to each other, and the PTC heaters 13 are sandwiched and laminated between the flat heat exchanger tubes 12 to constitute a set of heat exchange modules 14.

  Each flat heat exchanger tube 12 has a flat tube portion 12A having a flat cross-sectional shape with a thickness of about several millimeters formed by overlapping a pair of tube materials as described above, and heat formed at both end portions thereof. An inlet header portion 12B through which the medium flows in and an outlet header portion 12C through which the heat medium flows out are provided. Further, a corrugated inner fin (not shown) is inserted into the flat tube portion 12A. A plurality of heat medium flow passages are formed in the flat tube portion 12A.

  The three flat heat exchanger tubes 12 are sequentially laminated in the order of the lower, middle, and upper stages, and the inlet header portion 12B and the outlet header portion 12C at both ends thereof are connected to each other via a sealing material 27 (see FIG. 5) such as an O-ring. The communication holes (not shown) provided in the inlet header portion 12B and the outlet header portion 12C are communicated with each other. The three flat heat exchanger tubes 12 are assembled in a laminated state or sequentially laminated into a lower surface in the lower case 11A, and are heat-fixed and fixed to boss portions 11D (four locations) of the lower case 11A as will be described later. The presser member 15 is configured to be pressed and fixed toward the lower surface of the lower case 11A.

  Further, a PTC heater 13 is sandwiched between the three flat heat exchanger tubes 12 to constitute a set of heat exchange modules 14. As is well known, the plurality of sets (two sets) of PTC heaters 13 have electrode plates 24 arranged in contact with the upper and lower surfaces of a PTC element (Positive Temperature Coefficient) 23, respectively. The flat heat exchanger tubes 12 are laminated and arranged. The PTC heater 13 is incorporated into the inner bottom surface of the lower case 11A while being laminated together with the three flat heat exchange tubes 12 or sequentially laminated, and is attached to the lower surface of the lower case 11A via the heat exchange pressing member 15 as described above. It is configured to be pressed and fixed.

  The electrode plate 24 is for supplying electric power to the PTC element 23, and is made of an aluminum alloy plate material having a rectangular shape in plan view. This electrode plate 24 is disposed on both sides of the PTC element 23 so as to be in contact with the upper surface of the PTC element 23 and one sheet so as to be in contact with the lower surface of the PTC element 23. The PTC element 23 is sandwiched between the upper and lower surfaces by the electrode plate 24.

  Furthermore, the electrode plate 24 disposed on the upper surface side of the PTC element 23 is disposed such that the upper surface thereof is in contact with the lower surface of the flat heat exchanger tube 12 via an insulating sheet, and is disposed on the lower surface side of the PTC element 23. The electrode plate 24 is disposed such that its lower surface is in contact with the upper surface of the flat heat exchanger tube 12 via an insulating sheet. In the present embodiment, the electrode plate 24 is provided between the lower flat heat exchanger tube 12 and the middle flat heat exchanger tube 12, and between the middle flat heat exchanger tube 12 and the upper flat heat exchanger tube 12. A total of 4 sheets are arranged.

  These four electrode plates 24 have substantially the same shape as the flat tube portion 12A of each flat heat exchanger tube 12, and one terminal 24A is integrally provided on each long side. The terminals 24A are arranged along the long sides of the electrode plates 24 so that they do not overlap when the electrode plates 24 are stacked. In other words, the terminals 24A provided on each electrode plate 24 are provided with their positions slightly shifted along their long sides, and are provided so as to be arranged in series when the electrode plates 24 are stacked. ing. Each terminal 24A protrudes in the horizontal direction from the electrode plate 24 and has an L shape so as to extend further upward, and a plurality of sets (four sets) arranged in parallel on one side of the surface side of the control board 17 The terminal block 17B can be connected via a screw or the like.

  The three flat heat exchanger tubes 12 and the two sets of PTC heaters 13 are assembled on the inner bottom surface of the lower case 11A while being laminated or sequentially laminated as described above, and the upper surface of the uppermost flat heat exchanger tube 12 Are pressed in the direction of the inner bottom surface of the lower case 11A via the heat exchanger pressing members 15 that are fastened and fixed to the boss portions 11D (four locations) of the lower case 11A by four screws 25, thereby each flat heat exchanger tube. The upper and lower surfaces of the 12 inlet header portions 12B and the outlet header portion 12C and the flat tube portions 12A of the flat heat exchanger tubes 12 and the upper and lower surfaces of the PTC heater 13 are brought into close contact with each other.

  As a result, the heat exchange module 14 is incorporated into the casing 11, and the heat medium introduced from the heat medium inlet passage 11 </ b> B of the lower case 11 </ b> A flows from the inlet header portion 12 </ b> B of each flat heat exchanger tube 12 into the flat tube portion 12 </ b> A. In the process of being guided and flowing through the flat tube portion 12A, the temperature is raised by the PTC heater 13 and flows out to each outlet header portion 12C, from there through the heat medium outlet passage 11C of the lower case 11A, the heat medium heating device 10 It will be derived to the outside. The heat medium derived from the heat medium heating device 10 is supplied to the radiator 6 via the heat medium circulation circuit 10A (see FIG. 1).

  The heat exchanger pressing member 15 has a function as a heat sink for cooling a plurality of heat-generating electrical components 20 mounted on the surface of the control board 17 through a heat penetration portion 22 made of a highly heat conductive material such as copper or aluminum. It is made of an aluminum alloy plate. The heat exchanger pressing member 15 is sized to cover the upper surface of the flat heat exchanger tube 12, has a longitudinal dimension longer than that of the control board 17, and performs heat exchange including the flat heat exchanger tube 12 and the PTC heater 13. When the module 14 is pressed and fixed, it is fastened and fixed to the boss portion 11D of the casing 11 via the screw 25 at a position passing through the center line in order to ensure sealing performance around the inlet header portion 12B and the outlet header portion 12C. It is configured as follows.

  The pair of spacer members 16 are for avoiding interference with the control board 17 disposed on the upper surface side of the heat exchanger pressing member 15 when the position of the screw 25 for stopping the heat exchanger pressing member 15 is restricted to the above position. It is to be intervened. Among the spacer members 16, the spacer member 16 on the position side corresponding to at least the exothermic electrical component 20 mounted on the control board 17 is a high thermal conductive material such as an aluminum alloy plate material, for example. The heat from the component 20 can be transferred to the heat exchanger pressing member 15 through a heat penetration portion that penetrates the control board 17. The other spacer member 16 may be a resin material or the like.

  The control board 17 is fixed to the upper surface side of the heat exchanger pressing member 15 by a plurality of screws 26 with a pair of spacer members 16 interposed therebetween, and the heat penetration portion 22 is made of a high thermal conductivity material. 16 is arranged so as to be in contact with 16. A power harness 18 branched in a bifurcated manner is connected to the terminal block 17A of the control board 17, and an LV harness 19 is connected to the connector. Further, the terminal plate 17B is connected to the electrode plate 24 of the PTC heater 13. The extended L-shaped terminal 24 </ b> A is directly connected via a screw or the like, so that the control board 17 is incorporated on the heat exchanger pressing member 15 and accommodated and installed in the casing 11. .

  Furthermore, in the present embodiment, the temperature on the flat heat exchanger tube 12 side that heats the circulating heat medium by transferring the heat generated by the PTC heater 13 and the boss portion on the casing 11 side that fastens and fixes the heat exchanger pressing member 15. (Fixed part) In order to make the temperature difference with the temperature of 11D as small as possible and to make the difference in thermal expansion caused by the temperature difference of both parts as small as possible, the temperature on the flat heat exchanger tube 12 side and the boss part ( A means (temperature difference reducing means) 28 for reducing the temperature difference from the temperature of the fixed portion) 11D is provided.

  As shown in FIG. 5, the temperature difference reducing means 28 is provided with a heat medium and a flattened shape introduced into the inlet header portion 12 </ b> B of the flat heat exchanger tube 12 through the heat medium inlet passage 11 </ b> B provided in the casing 11. A portion of the heat medium that is circulated through the flat tube portion 12A of the heat exchanger tube 12 and led out from the outlet header portion 12C to the heat medium outlet passage 11C is transferred to the boss portion (fixed) on the casing 11 side via the heat medium flow passage 29. Part) It is constituted by the heat medium flow passages 29 and 30 that flow in the heat medium flow path 30 provided in 11D, and the temperature on the boss portion (fixed part) 11D side on the flat heat exchanger tube 12 side via the heat medium. This is to approach the temperature and minimize the temperature difference between the two parts.

  The heat medium flow passage 29 is formed by a passage member 32 attached to the bottom surface of the casing 11 via a sealing material 31. The heat medium provided on the bottom surface of the casing 11 is provided with the passage member 32. It is good also as a structure integrated with the inlet channel 11B and the heat-medium outlet channel 11C, and assembling | attaching to the casing 11. FIG.

  A plurality of exothermic electrical components 20 such as power transistors mounted on the surface of the control board 17 are accommodated and installed in the casing 11 and are close to the heat medium inlet path 11C provided in the lower case 11A. That is, the heat penetration part 22 which is arranged corresponding to the inlet header part 12B side of the plurality of flat heat exchange tubes 12 constituting the heat exchange module 14 and penetrates both surfaces of the control board 17, Cooling is performed via a heat exchanger pressing member 15 that is cooled by a heat medium having a relatively low temperature before heating that flows into the inlet header portion 12B, and a spacer member 16 that is made of a high thermal conductivity material.

  The heating medium heating device 10 includes three flat heat exchanger tubes 12 and two sets of PTC heaters 13 on the inner bottom surface of the lower case 11A of the casing 11, and insulating sheets (not shown) on both sides of the PTC heaters 13. While being sandwiched between the two, they are stacked one by one and assembled, and when the heat exchange module 14 is assembled, the upper surface of the heat exchange pressing member 15 is pressed and fixed to the lower case 11A side, or heat exchange is performed. After the module 14 is sub-assembled, the module 14 is assembled in the lower case 11A, and the upper surface thereof is pressed and fixed by the heat exchanger pressing member 15, and thereby, each flat heat exchanger tube 12 and each PTC heater are assembled. 13 can be incorporated in close contact with each other.

  Then, the control board 17 is screwed and fixed to the upper surface of the heat exchanger pressing member 15 with the spacer member 16 interposed therebetween, and after the electrical system is connected to the control board 17, an upper portion (not shown) covering the upper part is covered. The heat medium heating device 10 can be assembled by fixing the case to the lower case 11A with screws. The heat medium heating device 10 circulates the heat medium flowing into the inlet header portion 12B through the heat medium inlet passage 11B through the plurality of flat heat exchanger tubes 12, heated by the PTC heater 13, and then the outlet header portion 12C. By flowing out from the heat medium through the heat medium outlet passage 11C, the heat medium circulated in the heat medium circulation circuit 10A can be used for heating.

Thus, according to the heat medium heating device 10 and the vehicle air conditioner 1 of the present embodiment, the following operational effects can be obtained.
A plurality of flat heat exchanger tubes 12 are laminated, and each flat heat exchanger tube 12 and the PTC heater 13 are attached to the lower case 11A by the heat exchanger pressing member 15 in a state where the PTC heater 13 is sandwiched between the flat tube portions 12A. Since it is configured to be pressed and fastened against, a plurality of flat heat exchanger tubes 12 and a plurality of sets of PTC heaters 13 can be assembled in close contact with each other.

  Accordingly, the contact heat resistance between the flat heat exchanger tube 12 and the PTC heater 13 can be reduced to improve the heat transfer efficiency, and the heat medium heating device 10 can be improved in performance. By arranging the PTC heaters 13 in multiple layers, the plane area can be made as small as possible, and the heat exchange module 14 and thus the heat medium heating device 10 can be made compact and compact.

  Further, in the heat medium heating device 10, a casing to which a heat exchanger pressing member 15 that presses and fixes a plurality of flat heat exchanger tubes 12 and a plurality of sets of PTC heaters 13 stacked in multiple layers is screwed. In order to bring the temperature of the boss 11 (fixed part) 11D on the 11th side closer to the temperature on the flat heat exchanger tube 12 heated by the PTC heater 13 and minimize the temperature difference, the heat exchanger holding member 15 is fastened and fixed. The boss portion 11D is provided with a temperature difference reducing means 28 comprising heat medium flow passages 29 and 30 for flowing a part of the heat medium flowing / or flowing through the flat heat exchanger tube 12.

  For this reason, during the heating operation in which the PTC heater 13 is energized to heat the heat medium, the temperature on the flat heat exchanger tube 12 side heated by the PTC heater 13 with the heat medium as a mediating medium by the temperature difference reducing means 28, The temperature difference with the temperature on the boss portion 11D side that fastens and fixes the heat exchanger pressing member 15 of the casing 11 can be reduced as much as possible, and the difference in thermal expansion occurring at each part can be reduced. That is, the temperature of the boss portion 11 </ b> D is brought close to the temperature on the flat heat exchanger tube 12 side by circulating a part of the heat medium circulated in the flat heat exchanger tube 12 through the heat medium flow passages 29 and 30. be able to.

  As a result, a difference in thermal expansion occurs due to the temperature difference between the temperature on the flat heat exchanger tube 12 side and the temperature on the boss portion 11D side of the casing 11, and the stress exceeding the allowable value for the heat exchanger pressing member 15 and the casing 11. It eliminates the problems such as the application of heat or the pressing of the sealing material 17 that seals around the communication holes of the outlet / inlet header portions 12B and 12C of the flat heat exchanger tube 12 and the sealing performance decreases. In addition, the product quality and the reliability of the heat medium heating device 10 can be improved.

  Further, the temperature difference reducing means 28 can be simply configured by providing the heat medium flow passages 29 and 30 for flowing a part of the heat medium that circulates or circulates in the flat heat exchanger tube 12 to the boss portion 11D. Therefore, it is possible to reduce the stress applied to the heat exchanger pressing member 15 and the casing 11 by preventing the occurrence of an excessive difference in thermal expansion with simple means, without complicating the configuration. It is possible to stabilize the pressing force of the sealing material 27 sealing around the communication holes of the outlet / inlet header portions 12B and 12C of the flat heat exchanger tube 12 and prevent the deterioration of the sealing performance.

  Further, in the present embodiment, a plurality of flat heat exchanger tubes 12 are provided with sealing materials 27 such as O-rings and liquid gaskets around the communication holes of the inlet header portion 12B and the outlet header portion 12C. 27 is in close contact with the pressing force of the heat exchanger pressing member 15 to seal around the communication hole. For this reason, the PTC heater 13 between the flat heat exchanger tubes 12 is laminated by laminating a plurality of flat heat exchanger tubes 12 with the sealing material 27 interposed around the communication holes of the inlet header portion 12B and the outlet header portion 12C. The heat transfer efficiency between the flat heat exchanger tube 12 and the PTC heater 13 can be improved by facilitating the assembly and pressing it with the heat exchanger presser member 15, and the sealing performance by the sealing material 27 is improved. Can be secured.

  In addition, the temperature difference between the temperature on the flat heat exchanger tube 12 side and the temperature on the boss (fixed part) 11D side for fastening and fixing the heat exchanger pressing member 15 is reduced by providing the temperature difference reducing means 28. By reducing the difference in thermal expansion between the two parts, the flat heat exchanger tube 12 can be stably pressed through the heat exchanger pressing member 15 with a constant pressing force. Accordingly, it is possible to stabilize the tight seal around the communication hole by the sealing material 27 such as an O-ring or a liquid gasket, and to ensure the reliability for preventing the heat medium from leaking.

  In addition, the temperature difference between the temperature on the flat heat exchanger tube 12 side and the temperature on the boss portion (fixed part) 11D side of the casing 11 is the heat medium supplied to the radiator 6 disposed in the air flow passage 2. The vehicle air conditioner 1 can be heated and supplied via the small high-performance heat medium heating device 10 that eliminates the problems caused by the difference in thermal expansion due to the heat and improves the product quality and reliability. The heating performance of the vehicle can be improved and stabilized, leakage of the heat medium and the like can be eliminated, and the reliability of the vehicle air conditioner 1 can be improved.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, the flat heat exchanger tubes 12 are laminated in three layers, and the PTC heater 13 is incorporated between them. However, the present invention is not limited to this, and the flat heat exchanger tubes 12 and the PTC heaters 13 Of course, the number of stacked layers may be increased or decreased. Moreover, in the said embodiment, although the casing 11 is made from the resin material, it is not restricted to this, It is good also as metal, such as the product made from aluminum die-casting, and this is also included by this invention.

  Furthermore, although the said embodiment demonstrated the example using the flat heat exchanger tube 12 which provided the inlet header part 12B of the heat carrier in the one end side, and provided the outlet header part 12C in the other end side, the flat heat exchanger tube 12 is It is good also as a flat heat exchanger tube of the structure which connected the inlet header part 12B and the outlet header part 12C in the one end side, and connected with the flat tube 12A which formed the U-turn flow path which folds back in the other end side. In addition to the O-ring, for example, a liquid gasket or the like may be used as the sealing material 27 that seals the communication holes of the inlet header portion 12B and the outlet header portion 12C.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Air flow path 6 Radiator 10 Heat medium heating apparatus 10A Heat medium circulation circuit 11 Casing 11B Heat medium inlet path 11C Heat medium outlet path 11D Boss part (fixed part)
DESCRIPTION OF SYMBOLS 12 Flat heat exchanger tube 12A Flat tube part 12B Inlet header part 12C Outlet header part 13 PTC heater 15 Heat exchanger pressing member 27 Sealing material 28 Temperature difference reducing means 29, 30 Heat medium flow path (temperature difference reducing means)

Claims (4)

A casing provided with a heating medium outlet / inlet passage;
A plurality of flat heat exchange tubes that are communicated with the heat medium outlet / inlet passage of the casing and flow out of the outlet header portion after the heat medium flowing in from the inlet header portion flows through the flat tube portion;
A PTC heater incorporated between the flat tube portions of the plurality of flat heat exchanger tubes stacked on each other;
A heat exchanger pressing member that is clamped and fixed to a fixed part of the casing, and presses the flat heat exchanger tube and the PTC heater against the inner surface of the casing from one surface side of the flat heat exchanger tube, and
Means are provided for reducing a temperature difference between the temperature of the flat heat exchanger tube heated by the PTC heater and the temperature of the fixing portion of the casing to which the heat exchanger pressing member is fastened and fixed. A heat medium heating device.   The means for reducing the temperature difference is provided in a fixed part of the casing, and is constituted by a heat medium flow passage that circulates a part of the heat medium that circulates in the flat heat exchanger tube. The heat medium heating device according to claim 1.   The plurality of flat heat exchanger tubes are provided with a sealing material around the communication holes of the inlet header portion and the outlet header portion, and the sealing material is brought into close contact with the pressing force of the heat exchanger pressing member to surround the communication holes. The heat medium heating device according to claim 1, wherein the heat medium heating device is sealed. In the vehicle air conditioner configured such that the heat medium heated by the heat medium heating device can be circulated with respect to the radiator disposed in the air flow passage,
The vehicle air conditioner, wherein the heat medium heating device is the heat medium heating device according to any one of claims 1 to 3.

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