JP2014129090A - Heat medium heating device and vehicle air conditioner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability while reducing the manufacturing cost of a heat medium circulation box accommodating a PTC heater and circulating a heat medium.SOLUTION: In a heat medium heating device including a first heat medium circulation box and a second heat medium circulation box closely attached to both surfaces of a PTC heater 40, respectively, having a heat medium circulation passage formed inside, the first and second heat medium circulation boxes being fluid-tightly bonded to each other, a plurality of PTC elements 41a, 41b, and 41c constituting the PTC heater 40 are arranged along a channel direction of the heat medium circulation passage, these PTC elements 41a, 41b, and 41c have different widths from one another, and the PTC elements 41a, 41b, and 41c can be independently controlled to be turned on or off.

Description

  The present invention relates to a heat medium heating device that heats a heat medium using a PTC (Positive Temperature Coefficient) heater and a vehicle air conditioner using the same.

  2. Description of the Related Art Conventionally, as one of heat medium heating devices for heating a medium to be heated, one using a PTC heater having a positive temperature coefficient thermistor element (PTC element) as a heat generating element is known. The PTC heater has a positive thermistor characteristic, and the resistance value increases as the temperature rises. As a result, the current consumption is controlled and the temperature rises gradually. Reaches the saturation region and stabilizes, and has a self-temperature control characteristic.

  As described above, the PTC heater has a characteristic that the consumption current decreases as the heater temperature rises, and then stabilizes at a low value when the saturation temperature reaches a constant temperature. By utilizing this characteristic, it is possible to save power consumption and to obtain an advantage that an abnormal rise in the temperature of the heat generating portion can be prevented.

  For this reason, PTC heaters are used in many technical fields. In the field of air conditioning, for example, as disclosed in Patent Document 1, in an air conditioner for a hybrid vehicle, air heating when the engine is stopped is used. There has been proposed a heating medium heating device in which a PTC heater is applied to a heating device for heating a heating medium (here, engine cooling water) to be supplied to a radiator.

  In this heat medium heating device, two heat medium distribution boxes are liquid-tightly joined to each other via an O-ring, and a flat PTC heater is closely attached between these two heat medium distribution boxes. . In addition, each heat medium distribution box has a structure in which a plurality of box constituent members are joined in a liquid-tight manner via O-rings, and engine cooling water, which is a heat medium, is contained in each heat medium distribution box. A flow passage for circulation is formed.

  Each heat medium distribution box is formed with a flat heat radiating surface that is in close contact with the PTC heater, and between the flat surface and the joint surface formed on the outer peripheral portion of the heat medium distribution box (box component member). A groove-shaped step portion was formed (see FIG. 5 of Patent Document 1).

  This is a heat transfer path from the PTC heater to the O-ring in order to prevent the above-described O-ring interposed in the joint surface from being deteriorated in material due to high heat generated by the PTC heater and causing liquid leakage. This is to prevent overheating of the O-ring by lengthening the length. And the wiring member extended from a PTC heater was arrange | positioned in this level | step-difference part.

JP 2008-56044 A

  However, as described above, the heat medium heating device described in Patent Document 1 is a pair of heat medium distribution boxes in which a plurality of box constituent members are joined in a liquid-tight manner via O-rings. Since the plate-like PTC heaters are closely attached to each other, a large number of O-rings are required, the number of parts is increased, and the assembly work is complicated. It is also necessary to engrave a fitting groove for fitting the O-ring into the joint surface, and these matters have been a cause of increasing the manufacturing cost of the heat medium heating device.

  Further, since a stepped portion such as a groove is formed between the heat radiating surface in close contact with the PTC heater and the joint surface formed on the outer peripheral portion of the heat medium distribution box (box component member), the man-hours for processing the box component member In many cases, the production cost of the heat medium distribution box and thus the entire heat medium heating device is increased.

  Further, since the wiring member extending from the PTC heater is disposed between the PTC heater and the outer peripheral portion (joint surface) of the heat medium distribution box, the outer dimension of the heat medium distribution box is larger than the plane area of the PTC heater. This also increases the manufacturing cost of the heat medium heating device.

  The present invention has been made in view of such circumstances, and is capable of increasing the reliability while reducing the manufacturing cost of the heat medium distribution box that houses the PTC heater and distributes the heat medium. An object is to provide a medium heating device and a vehicle air conditioner using the same.

In order to achieve the above object, the present invention provides the following means.
That is, the heat medium heating device according to the present invention is configured by stacking a flat PTC heater and a plurality of box constituent members, and is in close contact with one surface side of the PTC heater to form a heat medium flow path therein. The first heat medium distribution box is formed by overlapping a plurality of box constituent members, and is in close contact with the other surface side of the PTC heater to form a heat medium distribution path, and the first A second heat medium distribution box that is liquid-tightly joined to the heat medium distribution box, and the heat in the first and second heat medium distribution boxes by heat radiation from both sides of the PTC heater. In the heat medium heating apparatus configured to heat the heat medium flowing through the medium flow path, a plurality of PTC elements constituting the PTC heater are arranged along the flow path direction of the heat medium flow path. Arranged, with varying widths of the plurality of PTC elements, characterized in that the respective PTC device was off controllable alone.

  According to this heat medium heating device, the wiring members of the PTC heater can be easily provided together on one end side in the longitudinal direction of the PTC heater, and at the same time, the heat amount of the PTC heater can be controlled with a simple configuration, and the heat medium heating device is compact. The manufacturing cost can be reduced and the reliability can be improved.

  The vehicle air conditioner according to the present invention further includes a blower that circulates outside air or vehicle interior air, a cooler provided on the downstream side of the blower, and a radiator provided on the downstream side of the cooler. The vehicle air conditioner is characterized in that the heat medium heated by the heat medium heating device of the above aspect is circulated in the radiator. Thereby, the reliability can be improved, reducing the manufacturing cost of a heat medium heating apparatus.

  As described above, according to the heat medium heating device and the vehicle air conditioner using the heat medium heating device according to the present invention, it is possible to reduce the manufacturing cost of the heat medium distribution box that houses the PTC heater and distributes the heat medium, and is reliable. Can be increased.

It is a schematic block diagram of the vehicle air conditioner which concerns on one Embodiment of this invention. It is a perspective view of the heat carrier heating device concerning one embodiment of the present invention. It is a disassembled perspective view of the heat medium heating apparatus which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which follows the IV-IV line of FIG. It is a longitudinal cross-sectional view which follows the VV line of FIG. It is the perspective view which turned the substrate accommodation box shown in FIG. 3 upside down. FIG. 7 is a bottom view of the upper heat medium distribution box as viewed in the direction of arrows VII-VII in FIG. 4. It is a top view of the lower heat carrier circulation box by the VIII-VIII arrow of FIG. It is the IX section enlarged view of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic configuration diagram of a vehicle air conditioner 1 according to the present embodiment. The vehicle air conditioner 1 is, for example, an air conditioner for a hybrid vehicle, and includes a casing 3 for forming an air flow path 2 that takes outside air or vehicle interior air, regulates the temperature, and guides it to the vehicle interior. ing.

  Inside the casing 3, the air or the cabin air is sequentially sucked from the upstream side to the downstream side of the air flow path 2 to increase the pressure, and the blower 4 pumps it to the downstream side, and the air pumped by the blower 4. The ratio between the cooler 5 that cools the radiator, the radiator 6 that heats the air that has passed through the cooler 5, the amount of air that passes through the radiator 6, and the amount of air that flows by bypassing the radiator 6 An air mix damper 7 that adjusts and adjusts the temperature of the air mixed on the downstream side thereof is installed.

  The downstream side of the casing 3 is connected to a plurality of blowout ports (not shown) through which the temperature-controlled air is blown into the vehicle compartment via a blowout mode switching damper (not shown) and a duct. The cooler 5 constitutes a refrigerant circuit together with a compressor, a condenser, and an expansion valve (not shown), and evaporates the refrigerant adiabatically expanded by the expansion valve, thereby cooling the air passing therethrough.

  The radiator 6 constitutes a heat medium circulation circuit 11 together with the tank 8, the pump 9, the engine (not shown), and the heat medium heating device 10 according to the present invention. As the heat medium flowing through the heat medium circuit 11, engine cooling water of the hybrid vehicle is used. The heat medium circulation circuit 11 heats the engine coolant by the heat medium heating device 10 when the temperature of the engine coolant that is the heat medium does not increase so much, such as during hybrid operation, and the heated engine coolant is pumped by the pump 9. By circulating through the heat medium circulation circuit 11, the air passing through the radiator 6 is heated in the casing 3.

  2 is a perspective view of the heat medium heating device 10, FIG. 3 is an exploded perspective view of the heat medium heating device 10, and FIGS. 4 and 5 are longitudinal cross-sectional views of the heat medium heating device 10. The figure is shown.

  The heat medium heating device 10 includes a plurality of box constituent members 50, 51, and a first heat medium distribution box A that is configured in a box shape by overlapping a plurality of box constituent members 20, 21, 30. A second heat medium distribution box B that is superposed and configured in a box shape and is liquid-tightly joined to the lower surface of the first heat medium distribution box A, and the first and second heat medium distribution And a PTC heater 40 sandwiched between the boxes A and B.

  In the first heat medium distribution box A, a rectangular substrate storage box 20 having a lid 21 bonded to the upper surface and an upper heat medium distribution box 30 having the same rectangular shape as the substrate storage box 20 are bonded in a liquid-tight manner. Is formed. The second heat medium distribution box B includes a lower heat medium distribution box 50 having the same rectangular shape as the upper heat medium distribution box 30 and a lid 51 that is liquid-tightly joined to the lower surface of the lower heat medium distribution box 50. And is formed. Between the first heat medium distribution box A and the second heat medium distribution box B and between the other box constituent members 20, 21, 30, 50, 51, as shown in FIGS. The plurality of bolts 58 are tightened and integrated.

  The PTC heater 40 has a rectangular and flat plate shape smaller than the upper heat medium distribution box 30 and the lower heat medium distribution box 50, and as will be described in detail later, the upper surface of the PTC heater 40 is the upper heat medium distribution box. The lower surface of the PTC heater 40 is in close contact with the flat heat radiating surface 56 formed on the upper surface of the lower heat medium distribution box 50.

  The substrate storage box 20 is a rectangular semi-enclosure made of a heat conductive material such as an aluminum alloy and whose upper surface is hermetically sealed by a lid 21. The interior of the substrate storage box 20 is a substrate storage portion S, which is a PTC heater. A control board 22 (see FIGS. 3 and 4) for controlling 40 is stored and installed. The control board 22 incorporates heat-generating components such as a field effect transistor (FET) 23 and a control circuit, and has a high voltage of 300 V for driving the PTC heater 40 and a low voltage of 12 V for control. Voltage.

  The control board 22 is fixedly installed on a support portion 24 protruding from the bottom surface of the board storage box 20 with four corners fastened with screws 25a. Further, the heat-generating component such as the FET 23 is disposed on the lower surface side of the control substrate 22 and is in contact with the upper surface of the cooling unit 26 provided on the bottom surface of the substrate housing box 20 via an insulating layer (not shown). Fastened and fixed by screws 25b. The heat generating component such as the FET 23 and the cooling unit 26 are disposed in the vicinity of the inlet side of a heat medium distribution path (flow passage 33), which will be described later, provided in the upper heat medium distribution box 30 in order to enhance the cooling effect on the heat generation component. The

  A wiring insertion hole 27 is formed in one end face of the substrate storage box 20 (see FIGS. 3 and 6), and a wiring member 40a (see FIG. 2) connected to the control substrate 22 is inserted through the hole. Further, a wiring communication hole 28 (see FIG. 6) through which a harness connecting the control board 22 and the PTC heater 40 passes is formed on the lower surface on one end side of the board housing box 20. Furthermore, a harness insertion hole 29 (see FIG. 3) is formed in the other end surface of the substrate storage box 20, and an electrical harness 22a (see FIG. 2) connected to the control board 22 is inserted through this hole.

  3 to 5 and 7 show the heat medium flow path of the upper heat medium flow box 30. The upper heat medium distribution box 30 is a rectangular semi-contained body made of a heat conductive material such as an aluminum alloy, and a pair of inlet headers 31 and outlet headers 32 formed at both ends on the upper surface side thereof. And a parallel groove-shaped flow passage 33 formed between the inlet header 31 and the outlet header 32 and separated by a large number of fins 33a. The top surfaces of the inlet header 31 and the outlet header 32 and the flow passage 33 are liquid-tightly closed by the bottom surface of the substrate storage box 20 (see FIGS. 4 and 5).

  As a result, between the substrate storage box 20 and the upper heat medium distribution box 30, the engine cooling water flowing into the inlet header 31 is distributed to a number of flow passages 33, and the inside of the flow passages 33 is simultaneously parallel. A flow path for engine coolant that flows and flows toward the outlet header 32 is formed. The engine coolant flowing in the flow passage 33 does not flow into the outlet header 32 as it is, but flows into a later-described flow port 35 (see FIG. 7) formed on the lower surface of the upper heat medium flow box 30. Note that the above-described cooling unit 26 provided on the bottom surface of the substrate storage box 20 is cooled by the engine cooling water flowing through the flow passage 33, whereby the cooling structure of the control board 22 is constructed.

  The inlet header 31 is provided with an inflow portion 34 for engine cooling water, and the outlet header 32 has a flow port 35 to the lower heat medium distribution box 50 and an engine flowing from the lower heat medium distribution box 50 as described later. A circulation port 36 for allowing cooling water to flow out and an outflow portion 37 for engine cooling water communicating with the circulation port 36 and communicating with the outside are provided. Union members 34 a and 37 a (see FIGS. 2 and 5) are attached to the inflow portion 34 and the outflow portion 37, respectively, which enable connection of hose members constituting the heat medium circulation circuit 11.

  Furthermore, a wide concave portion having a flat heat radiation surface 38 in close contact with the upper surface of the PTC heater 40 as a ceiling surface is provided on the lower surface side of the upper heat medium distribution box 30 (see FIGS. 4, 5, and 7). The recess faces the back surface of the flow passage 33 through which the engine coolant flows, and is formed so that the PTC heater 40 is fitted therein. A wiring insertion hole 39 (see FIG. 3) is formed through the upper end of the upper heat medium distribution box 30 on the opposite side to the distribution ports 35 and 36, and the wiring insertion hole 39 is formed in the board accommodation box. Align with the 20 wiring communication holes 28.

  3 to 5 and FIG. 8 show the heat medium flow path of the lower heat medium flow box 50. The lower heat medium distribution box 50 is a rectangular half casing made of a heat conductive material such as an aluminum alloy, and communication ports 52 and 53 are provided at one end thereof (see FIG. 8). The communication ports 52 and 53 are aligned with the flow ports 35 and 36 of the upper heat medium flow box 30, respectively.

  The lower heat medium distribution box 50 has a plurality of fins 54a (see FIG. 4) on the lower surface of the lower heat medium distribution box 50. The fins 54a extend to the other end from the communication port 52 and return to the communication port 53 by making a U-turn at the other end. Separated parallel groove-like flow passages 54 are formed. The U-shaped flow passage 54 is separated from the forward flow path and the return flow path by a partition wall 54b (see FIG. 4) that is taller than the fins 54a. The lower surface of the flow passage 54 is sealed with the lid 51 as described above, and a U-shaped shallow concave portion 55 (see FIG. 3) that matches the shapes of the flow passage 54 and the partition wall 54b is formed in the lid 51.

  Thereby, between the lower heat medium distribution box 50 and the lid 51, the engine coolant flowing into the communication port 52 is distributed from the communication port 52 to a number of flow passages 54, and the flow passages 54 are simultaneously parallel. Thus, a circulation path of the heat medium that reaches the communication port 53 is formed by making a U-turn at the other end.

  The communication port 52 of the lower heat medium distribution box 50 communicates with the distribution port 35 provided in the outlet header 32 of the upper heat medium distribution box 30, and the engine cooling water that has flowed through the flow passage 33 of the upper heat medium distribution box 30. Is supposed to flow in. Further, the communication port 53 of the lower heat medium distribution box 50 communicates with the distribution port 36 provided in the outlet header 32 of the upper heat medium distribution box 30, and the engine cooling water flowing through the lower heat medium distribution box 50 is A path that flows out from the circulation port 36 through the outflow portion 37 to the outside is configured.

  The upper surface of the lower heat medium distribution box 50 is a heat radiating surface 56 (see FIGS. 3 to 5 and 8), and the PTC heater 40 is sandwiched between the lower heat medium distribution box 50 and the flat heat radiating surface 38 on the lower surface of the upper heat medium distribution box 30. These heat radiation surfaces 38 and 56 are pressure-bonded to the compressible heat conductive layer 44 described later attached to both surfaces of the PTC heater 40.

  The configuration of the PTC heater 40 is shown in FIGS. 3, 4, and 7 to 9. The overall shape of the PTC heater 40 is a rectangle. The PTC heater 40 is configured by PTC elements 41a, 41b, and 41c as heating elements arranged in, for example, three rows along the flow direction of the heat medium flow path (flow path 33, flow path 54). is there. Of these three PTC elements 41a, 41b and 41c, the widths of the PTC elements 41a and 41c on both sides are wider than the width of the central PTC element 41b, for example, a double width.

  Each PTC element 41a, 41b, 41c is provided with an electrode plate 42, an incompressible insulating layer 43, and a compressible heat conductive layer 44 sequentially laminated on both surfaces thereof as shown in an enlarged cross section in FIG. It has a laminated structure. These PTC elements 41a, 41b, and 41c are each configured to be capable of on / off control alone by a control circuit incorporated in the control board 22.

  The electrode plate 42 is for supplying electric power to the PTC elements 41a, 41b, and 41c, and is the same rectangular thin plate as the PTC elements 41a, 41b, and 41c, and has electrical conductivity and thermal conductivity. The incompressible insulating layer 43 is a rectangular thin plate, is made of an insulating material such as a polyamide film, and has thermal conductivity. The incompressible insulating layer 43 has a thickness of 0.1 mm or less. This is between the PTC elements 41a, 41b, 41c and the electrode plate 42 and the upper heat medium distribution box 30 (heat radiation surface 56) and the lower heat medium distribution box 50 (heat radiation surface 38) provided on the outside thereof. This is to reduce the thermal resistance as much as possible and to ensure sufficient electrical insulation.

  Furthermore, the compressible heat conductive layer 44 is a rectangular sheet material having compressibility, and is made of an insulating sheet such as a silicon sheet and has heat conductivity. When the compressible heat conductive layer 44 is composed of a silicon sheet, the PTC element 41 that is a heat generating element, and the upper heat medium distribution box 30 (heat radiation surface 38) and the lower heat medium distribution box 50 (heat radiation surface 56). In order to make the thermal resistance between them as small as possible, the thickness is set to about 0.4 mm to 2.0 mm. Further, the compression function is secured by setting the thickness to at least 0.4 mm or more, and the compressibility is utilized when the PTC heater 40 is assembled between the upper heat medium distribution box 30 and the lower heat medium distribution box 50. Thus, the upper heat medium distribution box 30 and the lower heat medium distribution box 50 are securely adhered to the PTC heater 40, and the assembly dimension tolerance can be absorbed.

  Thus, as shown in FIGS. 4 and 5, the PTC heater 40 is provided with respect to the engine cooling water flowing through the upper heat medium distribution box 30 and the lower heat medium distribution box 50 provided in close contact with both surfaces thereof. The engine cooling water can be heated by releasing heat from both sides.

  A wiring member 40b is provided at one end of the PTC heater 40, and the wiring member 40b is refracted upward at a right angle with respect to the surface direction of the PTC heater 40, and the wiring insertion hole 39 of the upper heat medium flow box 30 and the board accommodation. It is inserted into the wiring insertion hole 28 of the box 20. The wiring member 40b is guided to the control board 22, and the cable-like wiring member 40a (see FIG. 2) is pulled out from the control board 22 through the wiring insertion hole 27 of the board housing box 20 as described above. It is. The wiring insertion hole 27 is fitted with a waterproof and dustproof wiring cap 40c.

  The heat medium circulation circuit 11 is connected to the inflow portion 34 of the upper heat medium distribution box 30. The low-temperature engine cooling water pumped from the pump 9 flows into the inlet header 31 from the inflow portion 34 and is distributed to each flow passage 33 (see FIG. 3). The engine coolant flowing through the respective flow passages 33 toward the outlet header 32 side is heated and heated by the PTC heater 40, and then merges in front of the outlet header 32 and passes through the distribution port 35 to the lower heat medium distribution box 50. Flows into the communication port 52.

  Then, the air is diverted from the communication port 52 to the respective flow passages 54, flows as shown by an imaginary line F in FIG. 8, and is U-turned at the other end while being heated by the PTC heater 40 again. It enters the outlet header 32 through the circulation port 36 of the medium distribution box 30, and returns to the heat medium circulation circuit 11 through the outflow portion 37. In this way, the engine coolant passing through the inside of the heat medium heating device 10 flows through both sides of the PTC heater 40 and circulates in the heat medium circuit 11 while being heated by the heat of the PTC heater 40, thereby The room is temperature-controlled.

  The PTC elements 41a, 41b, and 41c constituting the PTC heater 40 are configured to be capable of being turned on and off independently by a control circuit incorporated in the control board 22, and therefore flow into the heat medium heating device 10. Depending on the difference between the actual temperature of the incoming engine coolant and the required temperature (target temperature), the control board 22 is turned on and off individually for each PTC element 41a, 41b, 41c, and the heating capacity is increased. Be controlled. As a result, the engine coolant can be heated to a predetermined temperature and flowed out.

  Next, the main part of the present invention will be described. As shown in FIG. 4, the heat medium heating device 10 has a plurality of joint surfaces M1 to M4. And the joint surface between the first heat medium distribution box A and the second heat medium distribution box B, that is, the joint surface M1 between the upper heat medium distribution box 30 and the lower heat medium distribution box 50, The second heat medium distribution box B and the joint surfaces M2 and M3 between the substrate housing box 20, the lid 21 and the upper heat medium distribution box 30 constituting the one heat medium distribution box A are configured. The joining surface M4 between the lower heat medium distribution box 50 and the lid 51 is configured to be sealed with a liquid gasket. As the liquid gasket, a water- and heat-resistant silicone sealant that becomes rubber when cured is used.

  Further, the flow passage 33 that is the heat medium flow path of the first heat medium flow box A and the flow path 54 that is the heat medium flow path of the second heat medium flow box B are respectively connected to the joint surface cooling flow paths C1, C1. C2 is provided. These joint surface cooling channels C1 and C2 particularly cool the vicinity of the joint surface M1 where the heat of the PTC heater 40 is greatly heated among the respective joint surfaces M1 to M4 sealed with the liquid gasket. It is provided in order to prevent the liquid gasket applied to the material from being deteriorated by heat.

  The joint surface cooling flow path C1 is one or two flow paths close to the joint surface M1 among the plurality of flow paths 33, and the joint surface cooling flow path C2 is a joint of the plurality of flow paths 54. One or two flow paths close to the surface M1. These joint surface cooling channels C1 and C2 are provided at positions closer to the joint surface M1 than the edge of the PTC heater 40. For this reason, before the heat of the PTC heater 40 is transmitted to the joint surface M1, heat is exchanged by the engine cooling water flowing through the joint surface cooling flow paths C1 and C2, and the heat is not easily transmitted to the joint surface M1. Therefore, the liquid gasket that seals the joining surface M1 is protected from heat and durability is improved, and leakage of the heat medium from the joining surface M1 is prevented.

  Among the bonding surfaces M1 to M4, the bonding surface M3 between the lower surface of the substrate storage box 20 and the upper surface of the upper heat medium flow box 30 through which the wiring member 40b of the PTC heater 40 passes is shown in FIG. As shown in the surface shape of the lower surface side of the box 20, an external seal section M3a that seals between the heat medium flow path (flow path 33) and the outside, the heat medium flow path (flow path 33), and the substrate housing portion S. And a board sealing section M3b for sealing between the wiring insertion hole 28, which is a part communicating with the board. The width W2 of the substrate seal section M3b is set larger than the width W1 of the external seal section M3a. For example, W1 is 5 mm and W2 is 8 mm.

  As shown in FIG. 4, a stepped portion Mc is formed along the inner peripheral edge of one of the upper and lower surfaces of each of the bonding surfaces M1 to M4. By forming the stepped portion Mc, the liquid gasket is held at a predetermined thickness on the stepped portion Mc, and can be cured without receiving a pressing force. Without providing this stepped portion Mc, if both surfaces of each of the bonding surfaces M1 to M4 are made completely flat, when a pressure bonding force is applied to both surfaces, the liquid gasket applied between them will be removed from the range of the bonding surface. There is a concern that it will be completely extruded and sufficient sealing performance will not be maintained. The height of the stepped part Mc may be about 0.5 mm to 2.0 mm.

  Further, as shown in FIGS. 3, 4, and 8, for example, in the lower heat medium distribution box 50 constituting the second heat medium distribution box B, the heat dissipation surface 56 that is in close contact with the PTC heater 40, The joining surface M1 with the first heat medium distribution box A is formed as a continuous flat surface without a step.

  The heat medium heating device 10 according to the present embodiment is configured as described above. According to the heat medium heating device 10, the following effects can be obtained.

  First, the joint surfaces M1 to M4 between the box constituent members 20, 21, 30, 50, 51 constituting the first heat medium distribution box A and the second heat medium distribution box B are sealed with a liquid gasket. By comprising, the O-ring conventionally interposed in each joint surface M1-M4 can be abolished. As a result, the number of component parts and the assembly man-hours of the heat medium heating device 10 can be reduced, and the fitting grooves that have been engraved on the joining surfaces M1 to M4 in order to fit the O-rings are abolished. The processing man-hours of the box constituent members 20, 21, 30, 50, and 51 can be reduced, and thereby the manufacturing cost of the heat medium distribution box 10 can be significantly reduced.

  Further, since the joining surface cooling flow paths C1 and C2 are provided in the heat medium flow paths (flow paths 33 and 54) of the first heat medium flow box A and the second heat medium flow box B, they are sealed with a liquid gasket. Of the four bonded surfaces M1 to M4, the bonded surface M1 where the heat of the PTC heater 40 is greatly cooled can be satisfactorily cooled. For this reason, the liquid gasket applied to the joint surface M1 is prevented from being deteriorated by heat, and a technology for sealing only with the liquid gasket without using an O-ring is established, thereby reducing the manufacturing cost of the heat medium heating device 10. Can contribute greatly.

  Further, by providing the joint surface cooling channels C1 and C2 at positions closer to the joint surface M1 than the edge of the PTC heater 40, the liquid gasket applied to the joint surface M1 is more reliably secured. Can be protected from heat. In addition, since the positions of the flow passages 33 and 54 are closer to the joint surfaces M3 and M4 than the PTC heater 40, the heat of the PTC heater 40 hardly reaches the joint surfaces M3 and M4.

  The shape of the joint surface cooling channels C1 and C2 is not limited to that of the present embodiment, but may be other shapes. For example, in the present embodiment, the depth and width of the joint surface cooling channels C1 and C2 are the same as or narrower than the dimensions of the adjacent flow passages 33 and 54. , 54 so that more engine coolant flows through a portion closer to the joint surface M1 to further improve the cooling performance of the joint surface M1.

  Furthermore, in the heat medium heating device 10, the width of the substrate seal section M3b is larger than the width W1 of the external seal section M3a at the joint surface M3 through which the wiring member 40b of the PTC heater 40 passes among the joint surfaces M1 to M4. Since W2 is set large, the O-ring at the joint surface M3 is abolished and the manufacturing cost is reduced, but the leakage of water to the substrate housing portion S in which the control substrate 22 is housed is reliably prevented to heat the heating medium. The reliability of the device 10 can be increased.

  Moreover, in this heat medium heating device 10, a step between the heat radiation surface 56 of the lower heat medium distribution box 50 constituting the second heat medium distribution box B and the joint surface M1 of the first heat medium distribution box A is provided with a step. The upper surface of the lower heat medium distribution box 50 can be made into a completely flat plane, which makes it very easy to process the lower heat medium distribution box 50, and Manufacturing cost can be reduced.

  Further, in the heat medium heating device 10, the PTC heater 40, the first heat medium distribution box A and the second heat medium distribution box B are formed in a rectangular shape, and the wiring member 40b of the PTC heater 40 is formed as a PTC. Since the heaters 40 are collectively extended from the longitudinal end portion side, the wiring member of the PTC heater 40 is not interposed between the long side of the PTC heater 40 and the long side of the heat medium distribution box 10 as in the past. Yes. For this reason, the outer periphery dimension of the heat medium distribution box 10 can be brought close to the planar outer dimension of the PTC heater 40, and the width dimension of the heat medium distribution box 10 can be reduced to reduce the manufacturing cost.

  Further, in the heat medium heating device 10, the PTC elements 41a, 41b, 41c constituting the PTC heater are arranged in a plurality of rows along the flow direction of the heat medium flow path (flow paths 33, 54). The widths of the plurality of PTC heaters 41a, 41b, 41c are made different, and each of these PTC elements 41a, 41b, 41c can be controlled on and off as a single unit. 40b can be provided easily and at the same time, the amount of heat of the PTC heater 40 can be controlled with a simple configuration, and the manufacturing cost can be reduced and the reliability can be improved due to the downsizing of the heat medium heating device 10.

  Further, according to the vehicle air conditioner 1 according to the present invention, the blower 4 for circulating the outside air or the vehicle interior air, the cooler 5 provided on the downstream side of the blower 4, and the downstream side of the cooler 5 are provided. Since the engine cooling water heated by the heat medium heating device 10 according to the present invention is circulated in the heat radiator 6, the heat medium heating device 10 is reduced in size and the manufacturing cost is reduced. On the other hand, the reliability can be improved and, as a result, the reliability of the entire vehicle air conditioner 1 can be improved.

  In the present embodiment, an example in which the heat medium heating device is used in a vehicle air conditioner has been described. However, the heat medium heating device according to the present invention is applied to an air conditioner other than a vehicle, a heating device, a refrigeration device, or the like. Application is also possible.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 4 Blower 5 Cooler 6 Radiator 10 Heat medium heating device 20 Substrate accommodation box (box component)
21, 51 Lid (Box component)
30 Upper heat medium distribution box (box component)
33 Flow path (heat medium flow path)
40 PTC heaters 41a, 41b, 41c PTC element 50 Lower heat medium distribution box (box component)
54 Flow path (heat medium flow path)
A 1st heat carrier distribution box B 2nd heat carrier distribution box

In order to achieve the above object, the present invention provides the following means.
That is, the heat medium heating device according to the present invention is configured by stacking a flat PTC heater and a plurality of box constituent members, and is in close contact with one surface side of the PTC heater to form a heat medium flow path therein. The first heat medium distribution box is formed by overlapping a plurality of box constituent members, and is in close contact with the other surface side of the PTC heater to form a heat medium distribution path, and the first A second heat medium distribution box that is liquid-tightly joined to the heat medium distribution box, and the heat in the first and second heat medium distribution boxes by heat radiation from both sides of the PTC heater. in the heat medium heating device configured to heat medium is heated flowing in the medium flow path, a PTC module which constitutes the PTC heater, as along the flow direction of the heat medium flow path A plurality of columns arranged, with varying widths of the plurality of PTC modules, characterized in that the respective PTC module was off controllable alone.

The configuration of the PTC heater 40 is shown in FIGS. 3, 4, and 7 to 9. The overall shape of the PTC heater 40 is a rectangle. The PTC heater 40 is configured by PTC modules 41a, 41b, and 41c as heat generating elements arranged in, for example, three rows along the flow path direction of the heat medium flow path (flow path 33, flow path 54). is there. These three PTC modules 41a, 41b, and 41c are aggregates of PTC elements. Among these , the widths of the PTC modules 41a and 41c on both sides are wider than the width of the central PTC module 41b, for example, twice as large. The width is set.

Each PTC module 41a, 41b, 41c is provided with an electrode plate 42, an incompressible insulating layer 43, and a compressible heat conductive layer 44 sequentially laminated on both surfaces thereof as shown in an enlarged cross section in FIG. It has a laminated structure. These PTC modules 41a, 41b, and 41c are each configured to be capable of being controlled on and off independently by a control circuit incorporated in the control board 22.

Electrode plate 42 is for supplying power PTC module 41a, 41b, to 41c, PTC module 41a, 41b, the same rectangular thin plate and 41c, and has conductivity and thermal conductivity. The incompressible insulating layer 43 is a rectangular thin plate, is made of an insulating material such as a polyamide film, and has thermal conductivity. The incompressible insulating layer 43 has a thickness of 0.1 mm or less. This is between the PTC modules 41a, 41b, 41c and the electrode plate 42 and the upper heat medium distribution box 30 (heat radiation surface 56) and the lower heat medium distribution box 50 (heat radiation surface 38) provided on the outside thereof. This is to reduce the thermal resistance as much as possible and to ensure sufficient electrical insulation.

Furthermore, the compressible heat conductive layer 44 is a rectangular sheet material having compressibility, and is made of an insulating sheet such as a silicon sheet and has heat conductivity. When the compressible heat conductive layer 44 is composed of a silicon sheet, the PTC module 41 which is a heat generating element, and the upper heat medium distribution box 30 (heat radiation surface 38) and the lower heat medium distribution box 50 (heat radiation surface 56). In order to make the thermal resistance between them as small as possible, the thickness is set to about 0.4 mm to 2.0 mm. Further, the compression function is secured by setting the thickness to at least 0.4 mm or more, and the compressibility is utilized when the PTC heater 40 is assembled between the upper heat medium distribution box 30 and the lower heat medium distribution box 50. Thus, the upper heat medium distribution box 30 and the lower heat medium distribution box 50 are securely adhered to the PTC heater 40, and the assembly dimension tolerance can be absorbed.

The PTC modules 41a, 41b, and 41c constituting the PTC heater 40 are configured to be controlled on and off independently by a control circuit incorporated in the control board 22, and therefore flow into the heat medium heating device 10. Depending on the difference between the actual temperature of the engine cooling water coming in and the required temperature (target temperature), the control board 22 is turned on and off individually for each PTC module 41a, 41b, 41c, and the heating capacity is increased. Be controlled. As a result, the engine coolant can be heated to a predetermined temperature and flowed out.

Further, in the heat medium heating device 10, the PTC modules 41a, 41b, 41c constituting the PTC heater are arranged in a plurality of rows along the flow direction of the heat medium flow path (flow paths 33, 54). a plurality of PTC heaters 41a, 41b, together with varying the width of 41c, each of these PTC modules 41a, 41b, because of the oN-oFF control enables 41c alone, PTC module 41a, 41b, one longitudinal end side of the wiring members 41c 40b can be provided easily and at the same time, the amount of heat of the PTC heater 40 can be controlled with a simple configuration, and the manufacturing cost can be reduced and the reliability can be improved due to the downsizing of the heat medium heating device 10.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 4 Blower 5 Cooler 6 Radiator 10 Heat medium heating device 20 Substrate accommodation box (box component)
21, 51 Lid (Box component)
30 Upper heat medium distribution box (box component)
33 Flow path (heat medium flow path)
40 PTC heaters 41a, 41b, 41c PTC module 50 Lower heat medium distribution box (box component)
54 Flow path (heat medium flow path)
A 1st heat carrier distribution box B 2nd heat carrier distribution box

Claims (2)

A flat PTC heater;
A first heat medium distribution box formed by superimposing a plurality of box constituent members, and in close contact with one surface side of the PTC heater and having a heat medium distribution path formed therein;
Similarly, a plurality of box constituent members are overlapped, closely contacted with the other surface side of the PTC heater to form a heat medium flow path therein, and liquid-tightly joined to the first heat medium flow box A second heat medium distribution box,
In the heat medium heating device configured to heat the heat medium flowing through the heat medium flow path in the first and second heat medium flow boxes by heat radiation from both surfaces of the PTC heater,
The PTC elements constituting the PTC heater are arranged in a plurality of rows along the flow direction of the heat medium flow path, the widths of the plurality of PTC elements are made different, and each of these PTC elements is controlled on and off as a single unit. A heat medium heating device characterized by being made possible. In a vehicle air conditioner comprising a blower for circulating outside air or vehicle interior air, a cooler provided on the downstream side of the blower, and a radiator provided on the downstream side of the cooler,
A vehicle air conditioner configured to allow the heat medium heated by the heat medium heating device according to claim 1 to circulate in the radiator.

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