Heat medium heating device

Abstract

To provide a heat medium heating device capable of improving heat radiation efficiency of an electronic component having heat generation property.SOLUTION: A heat-transfer-medium heating apparatus (10) includes a circuit substrate (12), an electronic part (13) disposed on the circuit substrate, a metal flow-path member (22) in which a heat-transfer medium (M) flows through a flow path (21) therein, and a heater (11) disposed in the flow path and configured to heat the heat-transfer medium. A heat-sink 22H connected to an outer surface of the flow path and having an installation surface for the electronic part is formed integrally with the flow-path member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heat medium heating device. [Background technology]

[0002] A known heat medium heating device for use in a vehicle air conditioner is described in Japanese Patent Application Laid-Open No. 2018-133300 (Patent Document 1 below). This heat medium heating device includes a casing through which a heat medium flows, a PTC heater that heats the heat medium, and a control board that controls the PTC heater. The casing includes a board housing portion that houses the control board. The control board includes electronic components. The publication describes that the electronic components can include heat-generating electronic components such as IGBTs (Insulated Gate Bipolar Transistors) and FETs (Field Effect Transistors), as well as other electronic components. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-133300 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above configuration, the electronic components are arranged in the space inside the board housing and do not come into contact with any components other than the board body of the control board. If heat-generating electronic components are used, the heat generated by the electronic components will be transferred to the air inside the board housing. In such a case, the heat cannot be sufficiently dissipated from the electronic components, and they may overheat and stop functioning properly.

[0005] The present invention was completed in view of the above circumstances, and an object of the present invention is to provide a heat medium heating device that can improve the heat dissipation efficiency of heat-generating electronic components. [Means for solving the problem]

[0006] The heat medium heating device of the present invention is a heat medium heating device comprising a circuit board, electronic components arranged on the circuit board, a metal flow path member through which a heat medium flows in a flow path inside the metal flow path member, and a heater arranged in the flow path and heating the heat medium, and a heat sink portion connected to the outer surface of the flow path and having an installation surface for the electronic components is formed integrally with the flow path member.

[0007] With this configuration, the heat of the electronic component can be transferred from the heat sink portion to the heat medium inside the flow path, thereby improving the heat dissipation efficiency of the electronic component.

[0008] In the heat transfer medium heating device of the present invention, the flow path may have a cylindrical cross section, and the heat sink portion may be connected to an outer cylindrical surface of the flow path.

[0009] With this configuration, the cross section of the flow path is cylindrical, allowing the heat medium to flow smoothly inside the flow path. Also, since the heat sink is connected to the outer surface of the flow path, the height (distance) of the heat sink from the flow path can be reduced, making it possible to downsize the heat medium heating device and increase the contact area between the heat sink and the flow path.

[0010] In the heat medium heating device of the present invention, the flow path may be tubular and extend in a longitudinal direction, and the flow path may expand in diameter along a flow direction of the heat medium in the longitudinal direction.

[0011] With this configuration, bubbles generated in the heat medium by the heating of the heater flow along the flow direction and are easily discharged to the outside through the expanded flow path, preventing bubbles from remaining in the flow path and causing the heater to run dry.

[0012] In the heat medium heating device of the present invention, the heater has a shape extending in the axial direction, and the heater has a through hole along the axial direction, the heat medium introduced from one end side of the through hole exits from the other end side of the through hole to the outer surface side of the heater, then turns back at the inner wall surface of the flow path, and flows along the outer surface of the heater to the opposite side in the axial direction, and the corners of the inner wall surface of the flow path facing the other end of the through hole may be curved.

[0013] With this configuration, when the heat medium flows out from the other end of the through hole to the outer surface of the heater and then turns back at the inner wall surface of the flow path, the heat medium flows smoothly around the curved corners, thereby further improving the heat dissipation efficiency of electronic components via the heat medium.

[0014] In the heat medium heating device of the present invention, the heater may have a cylindrical cross section.

[0015] With this configuration, the heat transfer medium flows smoothly along the outer surface of the heater, further improving the heat dissipation efficiency of the electronic components via the heat transfer medium. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a heat medium heating device that can improve the heat dissipation efficiency of heat-generating electronic components. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an exploded perspective view of a heat medium heating device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the heat medium heating device. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] 4 is a cross-sectional view of the flow channel taken along a direction perpendicular to the paper surface of FIG. 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described. FIG. 1 is an exploded perspective view of a heat medium heating device according to an embodiment of the present invention, FIG. 2 is a perspective view of the heat medium heating device, and FIG. 3 is a cross-sectional view taken along line AA in FIG.

[0019] It should be noted that the present disclosure is not limited to these examples, but is intended to include all modifications within the meaning and scope equivalent to the claims as defined by the claims. In the following description, when multiple identical components are used, only some of the components may be designated by reference numerals, and the reference numerals of other components may be omitted.

[0020] In this specification, the configuration of the heat medium heating device 10 is described with the positive Z-axis direction as the upward direction, the negative Z-axis direction as the downward direction, the positive X-axis direction as the forward direction, and the positive Y-axis direction as the rightward direction, but the heat medium heating device 10 may be arranged differently in actual use.

[0021] The heat medium heating device 10 according to this embodiment is a device for heating a liquid (an example of a heat medium) such as water. The heat medium heating device 10 is installed in, for example, an electric vehicle (EV) and is used to heat the vehicle interior and keep the battery warm.

[0022] As shown in FIG. 1, the heat medium heating device 10 includes a heater 11, a circuit board 12, and a casing 20 that houses the heater 11 and the circuit board 12. The casing 20 has a flow path member 22 and various members 24 to 26 (described later) assembled to the flow path member 22, and a flow path 21 is formed inside the flow path member 22. A heat medium M flows through the flow path 21 and is heated by a heater 11 arranged in the flow path 21.

[0023] In this example, the heater 11 is a ceramic heater, and includes a cylindrical member 11A and a heating resistor (not shown) embedded inside the cylindrical member 11A. The cylindrical member 11A is mainly made of a ceramic material such as alumina. The heating resistor is made of a metal such as tungsten and has a serpentine thin wire shape. The heating resistor generates heat when a voltage is applied from a power supply device.

[0024] The heater 11 can be manufactured, for example, by sandwiching a metal pattern serving as a heating resistor between ceramic green sheets, wrapping the sheets around a rod-shaped mold, and firing the sheets. The heater 11 includes a flange portion 11B brazed to the outer circumferential surface of a cylindrical member 11A. The flange portion 11B is plate-shaped and has an annular shape. The flange portion 11B is located near the left end of the cylindrical member 11A.

[0025] 1, an electronic component 13 for controlling the output of the heater 11 is disposed on one surface (bottom surface) of the circuit board 12. The electronic component 13 is, for example, a switching element such as a FET or an IGBT. The electronic component 13 has the property of easily generating heat, and although it generates less heat than the heater 11, it still generates heat when powered on.

[0026] Electronic component 13 includes main body 13A and lead portions 13B electrically connected to circuit board 12. Main body 13A is made of resin and has a semiconductor element or the like embedded therein. Lead portions 13B are disposed on the side surfaces of main body 13A. Note that lead portions 13B may also be disposed on the upper surface of main body 13A (the surface facing circuit board 12).

[0027] Although not shown in detail, lead wires connected to the heater 11 and various other wirings are electrically connected to the circuit board 12. These wirings are also electrically connected to an external power source or the like via external connectors C1 and C2. The external connectors C1 and C2 are attached to the side surface of the flow path member 22 (positive direction of the X axis in FIG. 1).

[0028] As shown in FIG. 1, the casing 20 has a flow path member 22 and various members 24 to 26 assembled to the flow path member 22. The flow path member 22 is substantially box-shaped and integrally includes a cylindrical portion 22t (see FIG. 3) having a cylindrical cross section on the lower side that constitutes the outer surface of the flow path 21. The heater 11 is disposed inside the cylindrical portion 22t, and the gap between the cylindrical portion 22t and the heater 11 forms the flow path 21. The front side of the cylindrical portion 22t (left side of the Y axis in FIG. 1) is open. Also, an outlet 22Y, which serves as an end of the flow path 21, is formed integrally with the cylindrical portion 22t so as to protrude from one side surface of the cylindrical portion 22t (positive direction of the X axis in FIG. 1). The flow path member 22 is made of metal and can be formed by, for example, aluminum die casting.

[0029] Furthermore, a flat heat sink portion 22H is integrally connected to the outer surface of the cylindrical portion 22t. The flat surface (upper surface) of the heat sink portion 22H is a surface on which the electronic component 13 is placed. The circuit board 12 is accommodated in the internal space above the cylindrical portion 22t in the flow path member 22, and the main body portions 13A of the electronic components 13 (two in this example) mounted on the lower surface of the circuit board 12 are in contact with the flat surface (upper surface) of the heat sink portion 22H.

[0030] In this example, a resin holder 15 for holding the electronic component 13 and a resin insulating sheet (not shown) are interposed between the main body 13A of the electronic component 13 and the heat sink 22H. However, as long as the main body 13A and the heat sink 22H are spaced apart, no member needs to be interposed between them, and there may be an air gap between them. Furthermore, a clip 17 having a spring property is disposed on the upper side of the main body portion 13A, and the main body portion 13A is clamped between the clip 17 and the holder 15.

[0031] The opening on the top surface of the flow path member 22 that houses the circuit board 12 is then closed by the lid portion 23 via a frame-shaped seal member (packing) S1. In this example, the lid 23 is also made of metal. By making the flow path member 22 surrounding the circuit board 12 and the lid out of metal, an electromagnetic shielding effect can be achieved that shields the circuit board 12 from external noise.

[0032] In addition, at the opening on the front side (left direction of the Y axis in Figure 1) of the cylindrical portion 22t, a frame-shaped seal member (packing) S2, a seal member (O-ring) S3, a flange holder 24, and a seal member (O-ring) S4 are arranged in this order. The heater 11 is inserted through the seal members S2, S3, flange holder 24, and seal member S4, and the surface of the flange portion 11B of the heater 11 facing right along the Y axis is in contact with the seal member S4.

[0033] Furthermore, on the opposite surface of the flange portion 11B, a seal member (O-ring) S5, a heater base holder 25, a seal member (O-ring) S6, and a side cover 26 are arranged in this order. These seal members S5 and S6 liquid-tightly seal both sides of the heater base holder 25, while the seal member S5 is in close contact with the base end of the heater 11. The flange portion 11B of the heater 11 is also liquid-tightly sealed by the seal member S4. Furthermore, the flange portion 11B and base of the heater 11 are supported in a cantilevered manner by the flange holder 24 and the heater base holder 25.

[0034] The temperature sensor 25b is inserted into the heater base holder 25 so that it is held down by the forked portion of the clip 25a. The clip 25a is fixed to the heater base holder 25 with a screw (not shown). A harness (not shown) for output extraction extends from the temperature sensor 25b and is connected to the circuit board 12. Similarly, an outlet-side temperature sensor (not shown) is also disposed near the circuit board 12 inside the flow path member 22, and is fixed by a clip 27a having a similar shape to the clip 25a.

[0035] Meanwhile, an inlet 26X, which is one end of the flow path 21, is formed in the side cover 26 so as to protrude leftward along the Y axis, and a seal member S6 provides a liquid-tight seal between the side cover 26 (the inlet 26X) and the heater base holder 25. This allows the inlet 26X to communicate with the flow path 21 on the cylindrical portion 22t side. Furthermore, the opening of the flow path member 22 surrounding the outside of the cylindrical portion 22t is closed by a side cover 26 via a seal member S2. In this manner, the heat medium heating device 10 shown in FIG. 2 is assembled.

[0036] Next, the characteristic features of the present invention will be described with reference to FIG. As shown in FIG. 3, the heat sink portion 22H having an upper surface on which the electronic component 13 is mounted is connected to the outer surface of the flow path 21 (tubular portion 22t) and is formed integrally with the flow path member 22. With this configuration, the heat of the electronic component 13 can be transferred from the metal heat sink portion 22H to the heat medium M inside the flow path 21, and the heat dissipation efficiency of the electronic component 13 can be improved.

[0037] 4, in this example, the flow path 21 has a cylindrical cross section, and the heat sink portion 22H is connected to the cylindrical outer surface of the flow path 21 (tubular portion 22t). Note that FIG. 4 is a cross-sectional view taken along a line perpendicular to the plane of the paper in FIG. 3. With this configuration, the cross section of the flow path 21 (cylindrical portion 22t) is cylindrical, so that the heat medium M can flow smoothly inside the flow path 21. Furthermore, since the heat sink portion 22H is connected to the outer surface of the flow path 21 (cylindrical portion 22t) so as to penetrate therein, the height (distance) of the heat sink portion 22H from the flow path 21 (cylindrical portion 22t) can be reduced, making it possible to miniaturize the heat medium heating device 10 and also to increase the contact area between the heat sink portion 22H and the flow path 21.

[0038] Note that the cross section of the flow path 21 being "cylindrical" does not necessarily mean that the flow path 21 needs to have the same diameter over its entire length; for example, the diameter may be reduced in one direction along the longitudinal direction, or the diameter may be repeatedly reduced and expanded along the longitudinal direction.

[0039] Here, "connected to the cylindrical outer surface of the flow path 21" means that there is no gap G between the heat sink portion 22H and the outer surface of the flow path 21 (cylindrical portion 22t). In contrast to this, if the heat sink portion 220H is formed with a gap G between it and the outer surface of the flow path 21 (the cylindrical portion 22t) (as shown by the broken line in FIG. 4), the height (distance) of the heat sink portion 220H from the flow path 21 increases, which increases the size of the heat medium heating device 10. In addition, the contact area between the heat sink portion 220H and the flow path 21 decreases at the gap G, and the heat dissipation efficiency of the electronic component 13 is inferior to that when there is no gap G.

[0040] As shown in FIG. 3, in this example, the flow path 21 has a cylindrical shape extending in the longitudinal direction L, and the flow path 21 expands in diameter along the flow direction F of the heat medium M in the longitudinal direction L. With this configuration, bubbles generated in the heat medium M by the heating of the heater 11 flow along the flow direction F and are easily discharged to the outside (exhaust port 22Y) from the expanded flow path 21, thereby preventing bubbles from remaining in the flow path 21 and causing the heater 11 to run dry.

[0041] As will be described later, in this example, the heater 11 has through-holes 11H, and the heat medium M also flows through the through-holes 11H, but the "flow path 21" is defined as a region surrounded by the flow path member 22 (the cylindrical portion 22t). That is, in this example, the "flow path 21" is a region between the inner surface of the cylindrical portion 22t and the outer surface of the heater 11. Therefore, the flow direction F of the heat medium M in the "flow path 21" is the flow direction between the inner surface of the cylindrical portion 22t and the outer surface of the heater 11, and is the direction toward the left of the Y axis in Fig. 3. Since the flow path 21 expands in diameter toward the left of the Y axis in Fig. 3, it can be said that "the flow path 21 expands in diameter along the flow direction F of the heat medium M."

[0042] 3, in this example, the heater 11 has a shape extending in the axial direction AX, and the heater has a through hole 11H along the axial direction AX. The heat medium M introduced from one end side of the through hole 11H (left side of the Y axis in FIG. 3) flows out to the outer surface side of the heater 11 from the other end 11e side of the through hole 11H, turns back at the inner wall surface of the flow path 21, and flows along the outer surface of the heater 11 to the opposite side in the axial direction AX (right side of the Y axis in FIG. 3). Here, a corner 21e of the inner wall surface of the flow path 21 facing the other end 11e of the through-hole 11H is curved.

[0043] With this configuration, when the heat medium M flows out from the other end 11e of the through hole 11H to the outer surface of the heater 11 and then turns back at the inner wall surface of the flow path 21, the heat medium M flows smoothly at the curved corner portion 21e, thereby further improving the heat dissipation efficiency of the electronic component 13 via the heat medium M. In this example, the axial direction AX is parallel to the longitudinal direction L, but this is not limiting, and the axial direction AX and the longitudinal direction L may intersect.

[0044] In this example, the heater 11 has a cylindrical cross section. With this configuration, the heat medium M flows smoothly along the outer surface of the heater 11, so that the heat dissipation efficiency of the electronic component 13 via the heat medium M can be further improved.

[0045] It goes without saying that the present invention is not limited to the above-described embodiments, but covers various modifications and equivalents that fall within the spirit and scope of the present invention. In the above embodiment, the heater 11 is a ceramic heater, but it may also be a PTC heater or a sheath heater. In the above embodiment, the heater is cylindrical, but the shape of the heater can be changed as appropriate. The cross-sectional shape of the flow path is not limited. [Explanation of symbols]

[0046] 10 Heat medium heating device 11 Heater 11H through hole 11e Other end of through hole 12 Circuit Board 13 Electronic Components 21 Flow path 21e Corner of the inner wall surface of the flow channel 22 Flow path member 22H Heat sink part M Heat medium L Longitudinal direction AX axis direction

Claims

1. A circuit board; electronic components disposed on the circuit board; a metal flow path member through which a heat transfer medium flows; a heater disposed in the flow path and configured to heat the heat medium, A heat transfer medium heating device, characterized in that a heat sink portion connected to an outer surface of the flow path and having an installation surface for the electronic component is formed integrally with the flow path member.

2. 2. The heat medium heating device according to claim 1, wherein the flow path has a cylindrical cross section, and the heat sink portion is connected to an outer surface of the cylindrical flow path.

3. The flow path has a cylindrical shape extending in the longitudinal direction, 3. The heat medium heating device according to claim 1, wherein the flow path expands in diameter along the flow direction of the heat medium in the longitudinal direction.

4. the heater has a shape extending in an axial direction, and the heater has a through hole along the axial direction; the heat medium introduced from one end side of the through hole flows out from the other end side of the through hole to the outer surface side of the heater, turns back at the inner wall surface of the flow path, and flows along the outer surface of the heater to the opposite side in the axial direction, 3. The liquid heat transfer medium heating device according to claim 1, wherein a corner of the inner wall surface of the flow path facing the other end of the through hole is curved.

5. 3. The liquid heat transfer medium heating device according to claim 1, wherein the heater has a cylindrical cross section.

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