Heat pipe and electrical device

Abstract

A heat pipe (10) is disposed inside an electrical device (1) and attached to an object, the heat pipe (10) comprising: a bottom section (11) having a contact surface (13) that comes into contact with the object; a peripheral wall section (12) extending from the bottom section (11) in a direction intersecting the contact surface (13); a sealed space (14) formed inside the bottom section (11) and the peripheral wall section (12); and an operating fluid (15) disposed so as to occupy a part of the sealed space (14).

Description

Technical Field

[0001] This invention relates to heat pipes and electrical devices. Background Technology

[0002] Electrical equipment used in vehicles such as electric vehicles and hybrid vehicles includes components that are prone to heat generation, and a structure is provided for dissipating heat from these components. As such a structure, a heat dissipation structure for a semiconductor circuit breaker is disclosed in Japanese Patent Application Publication No. 2016-18924 (hereinafter referred to as Patent Document 1). This heat dissipation structure for a semiconductor circuit breaker is a structure that releases heat generated in the semiconductor circuit breaker, which cuts off or connects predetermined objects to each other by opening / closing. It includes a metal busbar on which the semiconductor circuit breaker is mounted and a metal heat pipe disposed in contact with the busbar. The end of the heat pipe opposite to the end that contacts the busbar is connected to a heat dissipation member. Examples of heat dissipation members include the cover of a battery pack, the vehicle body, etc. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-18924 Summary of the Invention The problem that the invention aims to solve

[0004] When the aforementioned heat dissipation structure of the semiconductor circuit breaker is installed in a vehicle, if the vehicle is tilted on a slope or other incline, the working fluid inside the heat pipe tends to be positioned towards the end of the heat pipe's heat dissipation component, and there may be almost no working fluid on the busbar side of the heat pipe. In such a case, it is difficult to effectively absorb the heat generated in the semiconductor circuit breaker through working fluid vaporization. Solution for solving the problem

[0005] The heat pipe of the present invention is disposed inside an electrical device and installed on an object. The heat pipe includes: a bottom having a contact surface that contacts the object; a peripheral wall extending from the bottom in a direction intersecting the contact surface; a sealing space formed inside the bottom and the peripheral wall; and a working fluid disposed in such a way that it occupies a portion of the sealing space.

[0006] In addition, the electrical device of the present invention includes: the heat pipe described above; a heating element; and a busbar connected to the heating element and on which the heat pipe is installed. Invention Effects

[0007] According to the present invention, a heat pipe and electrical device are provided that can effectively release heat from an object. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the main parts of the electrical equipment according to Embodiment 1. Figure 2 This is a 3D diagram of a heat pipe. Figure 3 This is a three-dimensional view of the heat pipe before the inlet pipe section is sealed. Figure 4 yes Figure 2 AA sectional view. Figure 5 yes Figure 4 BB cross-sectional view. Figure 6 yes Figure 4 CC section view. Figure 7 yes Figure 4 DD sectional view. Figure 8 It is a cross-sectional view showing the configuration of the working fluid when the electrical equipment is arranged on a horizontal plane. Figure 9 It is a cross-sectional view showing the configuration of the working fluid in an electrical device in an inclined state. Figure 10 This is a three-dimensional view of the heat pipe in Embodiment 2. Figure 11 yes Figure 10 The cross-sectional view is consistent with that of Embodiment 1. Figure 4 The corresponding diagram. Figure 12 yes Figure 10 The cross-sectional view is consistent with that of Embodiment 1. Figure 7 The corresponding diagram. Figure 13 This is a cross-sectional view showing the state of the heat pipes installed on the busbar. Figure 14 This is a perspective view of the heat pipe in Embodiment 3. Figure 15 This is a diagram showing the heat pipe as viewed from one side of direction 1. Figure 16 This is a cross-sectional view of the heat pipe, which is consistent with Embodiment 1. Figure 4 The corresponding diagram. Figure 17 This is a three-dimensional view of the heat pipe in embodiment 4. Figure 18 This is a cross-sectional view of the heat pipe, which is consistent with Embodiment 1. Figure 4 The corresponding diagram. Figure 19 This is a perspective view of the heat pipe in embodiment 5. Figure 20 This is a cross-sectional view of the heat pipe, which is consistent with Embodiment 1. Figure 4 The corresponding diagram. Detailed Implementation

[0009] [Description of embodiments of the present invention] First, embodiments of the present invention will be described. [1] The heat pipe of the present invention is disposed inside an electrical device and installed on an object. The heat pipe comprises: a bottom having a contact surface that contacts the object; a peripheral wall extending from the bottom in a direction intersecting the contact surface; a sealing space formed inside the bottom and the peripheral wall; and a working fluid disposed in such a way that it occupies a portion of the sealing space.

[0010] With this structure, even when the electrical equipment is tilted, at least a portion of the working fluid is easily positioned in contact with the bottom, thus facilitating heat transfer from the object to the working fluid. Therefore, heat from the object can be effectively released through the vaporization of the working fluid.

[0011] [2] The heat pipe described above [1] preferably also has a plurality of heat sinks extending from the peripheral wall portion.

[0012] With this structure, the heat from the heat pipe can be easily released to the outside air by setting up heat sinks.

[0013] [3] In either [1] or [2] above, it is preferred that the bottom is circular and the peripheral wall extends from the outer edge of the bottom.

[0014] With this structure, regardless of the orientation of the electrical equipment, at least a portion of the working fluid can be easily configured to contact the bottom. This allows for more efficient heat dissipation from the object.

[0015] [4] In any of [1] to [3] above, preferably, a through hole is formed at the bottom for fastening the heat pipe bolt to the object.

[0016] Based on this structure, the heat pipe can be installed onto the object by bolt fastening.

[0017] [5] In any of [1] to [4] above, it is preferred that the peripheral wall portion is positioned above the bottom when the electrical equipment is arranged on a horizontal plane.

[0018] This structure maximizes the volume of the working fluid, which is positioned in contact with the bottom without tilting the electrical equipment. Therefore, it more effectively releases heat from the object.

[0019] [6] The electrical device of the present invention comprises: a heat pipe of any one of [1] to [5] above; a heating element; and a busbar connected to the heating element and on which the heat pipe is installed.

[0020] This structure allows for the effective release of heat transferred from the heating components to the busbar.

[0021] [Detailed Description of Embodiments of the Invention] The embodiments of the present invention will now be described. The present invention is not limited to these illustrations, but is shown through the claims and is intended to include all modifications within the meaning and scope equivalent to the claims. In the accompanying drawings, for ease of description, sometimes a portion of the structure is shown enlarged or simplified. Furthermore, the dimensional ratios of the various parts sometimes differ in the various drawings. Regarding multiple identical components, sometimes only some components are labeled with reference numerals, omitting the reference numerals of other components. The terms "orthogonal" and "parallel" in this specification include not only cases where they are strictly orthogonal and parallel, but also cases where they are substantially orthogonal and parallel to the extent that they serve the function and effect of this embodiment.

[0022] <Implementation Method 1> Reference Figures 1 to 9 Embodiment 1 of the present invention will be described. An electrical device 1 equipped with the heat pipe 10 of this embodiment is, for example, mounted in a vehicle such as an electric vehicle or a hybrid vehicle, and configured in a power supply path that connects a power source such as a battery and a load such as an electric motor. In the following description, the direction orthogonal to the contact surface 13 of the heat pipe 10 is designated as the first direction D1 (refer to...). Figure 4 Let's define any direction orthogonal to the first direction D1 as an in-plane direction for explanation.

[0023] (Electrical Equipment 1) like Figure 1 As shown, the electrical device 1 includes a relay 2 (an example of a heating element), a busbar 3 (an example of an object) connected to the relay 2, and a heat pipe 10 installed on the busbar 3. Additionally, the electrical device 1 includes a housing (not shown) that houses the relay 2, the busbar 3, and the heat pipe 10.

[0024] (Relay 2, Busbar 3) The relay 2 comprises a block-shaped main body 2A and a terminal portion 2B. The terminal portion 2B has, for example, a fastening hole for bolting a busbar 3. The busbar 3 is constructed of a conductive metal sheet. The busbar 3 includes a connection portion 3A electrically connected to the relay 2 and a mounting portion 3B for mounting a heat pipe 10. The connection portion 3A is connected to the terminal portion 2B, for example, by bolting. The mounting portion 3B is flat in the first direction D1. The mounting portion 3B has an outer surface 3B1 that contacts the heat pipe 10. The outer surface 3B1 is a surface disposed on one side of the mounting portion 3B in the first direction D1, orthogonal to the first direction D1. To effectively dissipate the heat generated by the relay 2, the mounting portion 3B is preferably disposed near the connection portion 3A.

[0025] (Heat pipe 10) Heat pipe 10 is made of metal. For example... Figure 2As shown, the heat pipe 10 has a bottom 11 and a peripheral wall portion 12, the peripheral wall portion 12 extending from the outer edge of the bottom 11 toward one side in the first direction D1.

[0026] (Bottom 11, Peripheral wall 12, Contact surface 13) The bottom 11 is circular when viewed from the first direction D1 (see reference). Figures 5 to 7 ).like Figure 4 As shown, the bottom 11 has a first wall 11A and a second wall 11B, with the second wall 11B disposed on one side of the first wall 11A in the first direction D1. Figure 4 (See the diagram above). The peripheral wall portion 12 includes: an outer wall 12A, connected to the end of the first wall 11A in the in-plane direction; an inner wall 12B, connected to the end of the second wall 11B in the in-plane direction; and a cylindrical portion 12C extending from the outer wall 12A. The ends of the outer wall 12A and the inner wall 12B on one side in the first direction D1 are connected by a connecting end 12D. In addition, the end of the cylindrical portion 12C in the in-plane direction away from the inner wall 12B is sealed by a sealing portion 12C1. Figure 8 As shown, the first wall 11A has a contact surface 13 that contacts the outer surface 3B1 of the mounting portion 3B of the busbar 3. The contact surface 13 is fixed to the outer surface 3B1, for example, by bonding with an adhesive, welding, or the like.

[0027] (Sealed space 14) like Figure 4 As shown, a sealing space 14 is formed inside the bottom 11 and the peripheral wall portion 12. Specifically, the sealing space 14 is composed of a first space 14A and a second space 14B. The first space 14A is formed inside the bottom 11, and the second space 14B communicates with the first space 14A and is formed inside the peripheral wall portion 12. The sealing space 14 is depressurized. The first space 14A is the space formed between the first wall 11A and the second wall 11B. Figure 7 As shown, the first space 14A extends in the in-plane direction. (As...) Figure 5 and Figure 6 As shown, the second space 14B is a space composed of an outer wall 12A, an inner wall 12B, and a cylindrical portion 12C. The second space 14B is approximately annular when viewed from the first direction.

[0028] (Working solution 15) like Figure 8 and Figure 9 As shown, the working fluid 15 is sealed in the sealed space 14. Figures 4 to 7 (Not shown in the diagram). The working fluid 15 can be, for example, water, antifreeze, etc. The liquid working fluid 15 occupies a portion of the sealed space 14. Hereinafter, unless otherwise specified, "working fluid 15" refers to the liquid state.

[0029] Heat pipe 10 can be manufactured, for example, using a 3D printer. First, forming... Figure 3 The unsealed body 10A is shown. The unsealed body 10A is the state of the heat pipe 10 before the formation of the sealed space 14, that is, before the sealing cylinder 12C. The opening 12C2 of the cylinder 12C of the unsealed body 10A is connected to a pressure reducing pump, for example, via a hose, and the internal space of the unsealed body 10A (corresponding to the subsequent sealed space 14) is depressurized. Furthermore, the working fluid 15 is injected into the internal space of the unsealed body 10A from the cylinder 12C via a hose or the like. Finally, by tightening the cylinder 12C, the sealing part 12C1 is formed, and the manufacturing of the heat pipe 10 is completed (see reference). Figure 8 ).

[0030] like Figure 8 As shown, with the electrical device 1 positioned on a horizontal plane (orthogonal to the vertical direction), the contact surface 13 is arranged parallel to the horizontal plane. Furthermore, the first direction D1 is the vertical direction, with one side of the first direction D1 being upward and the other side being downward. Therefore, the peripheral wall portion 12 is positioned upward relative to the bottom 11. The liquid working fluid 15 is biased towards the first wall 11A side of the first space 14A due to gravity. On the other hand, most of the second space 14B is occupied by a depressurized gas, including the gaseous working fluid 15.

[0031] When the relay 2 heats up due to the use of electrical equipment 1, the heat generated by the relay 2 is transferred to the busbar 3. Heat is then transferred from the contact surface 13, which contacts the outer surface 3B1 of the mounting portion 3B, to the heat pipe 10. Here, because the working fluid 15 is positioned towards the side with the contact surface 13 on the first wall 11A, the working fluid 15 easily vaporizes. Therefore, through the vaporization of the working fluid 15, the heat from the relay 2 is easily released via the busbar 3. When the working fluid 15 vaporizes, it rises from the first space 14A and moves towards the second space 14B. Furthermore, the vaporized working fluid 15 is cooled and condensed (liquefied) by exchanging heat with the external gas through the peripheral wall portion 12 in the second space 14B. The working fluid 15, now liquid again, falls back into the first space 14A due to gravity. By repeatedly performing this vaporization and condensation of the working fluid 15, the busbar 3 and consequently the relay 2 can be cooled.

[0032] like Figure 9 As shown, electrical equipment 1 is positioned relative to the horizontal plane ( Figure 9When the plane formed by the single-dot dashed line is tilted at an angle A1 (for example, when a vehicle carrying electrical equipment 1 is tilted on a slope), the contact surface 13 is configured to form an angle A1 with the horizontal plane, and a portion of the liquid working fluid 15 moves into the second space 14B. However, a portion of the liquid working fluid 15 remains in the first space 14A. Therefore, even when the electrical equipment 1 is tilted at an angle A1 with respect to the horizontal plane, the relay 2 can be effectively cooled by the vaporization of the working fluid 15.

[0033] Furthermore, the bottom 11 is circular when viewed from the first direction D1, and the peripheral wall 12 extends from the outer edge of the bottom 11 toward the first direction D1. Therefore, if the tilt angle A1 is the same, regardless of which direction the electrical device 1 is tilted relative to the horizontal plane, approximately the same amount of working fluid 15 (sometimes only the volume inside the cylinder 12C is different) is disposed in at least a portion of the first space 14A.

[0034] The relationship between the proportion of the working fluid 15 occupying the first space 14A and the tilt angle A1 can be set, for example, by adjusting the volume ratio of the first space 14A and the second space 14B, and the volume ratio of the working fluid 15 relative to the sealed space 14. For example, it can also be set such that when the tilt angle A1 is 45° or less, at least a portion (e.g., one-third) of the first space 14A is filled with the working fluid 15.

[0035] (Effects of Implementation Method 1) (1-1) In embodiment 1, the heat pipe 10 is disposed inside the electrical equipment 1 and installed on the object (busbar 3). The heat pipe 10 has: a bottom 11 having a contact surface 13 that contacts the object; a peripheral wall portion 12 extending from the bottom 11 in a direction (first direction D1) intersecting the contact surface 13; a sealing space 14 formed inside the bottom 11 and the peripheral wall portion 12; and a working fluid 15 disposed in such a way that it occupies a portion of the sealing space 14.

[0036] With this structure, even when the electrical equipment 1 is tilted, at least a portion of the working fluid 15 is easily positioned to contact the bottom 11, thus facilitating heat transfer from the object to the working fluid 15. Therefore, by vaporizing the working fluid 15, heat from the object can be effectively released.

[0037] (1-2) In Embodiment 1, the bottom 11 is circular and the peripheral wall 12 extends from the outer edge of the bottom 11.

[0038] With this structure, regardless of the tilt direction of the electrical device 1, at least a portion of the working fluid 15 can be easily configured to contact the bottom 11. Therefore, heat is released from the object more effectively.

[0039] (1-3) In Embodiment 1, with the electrical equipment 1 positioned on a horizontal plane, the peripheral wall portion 12 is positioned above the bottom portion 11.

[0040] With this structure, the volume of the working fluid 15, which is positioned in contact with the bottom 11 without tilting the electrical device 1, can be maximized. Therefore, the heat of the object can be released more effectively.

[0041] (1-4) The electrical device 1 of Embodiment 1 includes a heat pipe 10, a heating element (relay 2) and a busbar 3. The busbar 3 is connected to the heating element and is equipped with the heat pipe 10.

[0042] With this structure, the heat transferred from the heating component to the busbar 3 can be effectively released.

[0043] <Implementation Method 2> Reference Figures 10 to 13 Embodiment 2 of the present invention will be described. Except for the structure of the bottom 111, the heat pipe 110 and electrical device 101 of Embodiment 2 are constructed in the same manner as those of Embodiment 1. Therefore, the description of components and effects that are the same as those of Embodiment 1 is omitted.

[0044] (Through-hole 116) like Figure 10 As shown, a through hole 116 is formed at the center of the bottom 111 of the heat pipe 110. The through hole 116 penetrates the bottom 111 in the first direction D1. Figure 11 As shown, the inner wall portion 116A constituting the through hole 116 connects the first wall 11A and the second wall 11B of the bottom 111. Figure 12 As shown, the inner wall portion 116A is annular when viewed from the first direction D1.

[0045] like Figure 13 As shown, a bolt 4 is inserted into the through hole 116. The bolt 4 is used to install the heat pipe 110 to the busbar 3. The bolt 4 is inserted into the through hole 3C formed in the busbar 3 and is fastened by a nut 5. The nut 5 is housed in the nut housing 6A of the housing 6.

[0046] (Effects of Implementation Method 2) (2-1) In embodiment 2, a through hole 116 is formed at the bottom 111, and the through hole 116 is used to fasten the heat pipe 110 to the object.

[0047] Based on this structure, the heat pipe 110 can be installed onto the object by bolt fastening.

[0048] <Implementation Method 3> Reference Figures 14 to 16Embodiment 3 of the present invention will be described. The heat pipe 210 of Embodiment 3 is constructed in the same manner as that of Embodiment 2, except that it has heat sink 220. Therefore, the description of the same components and effects as those in Embodiment 2 is omitted.

[0049] (Heater 220) like Figure 14 As shown, the heat pipe 210 has a plurality of heat sinks 220 extending from the outer wall 12A of the peripheral wall portion 12. The heat sinks 220 are plate-shaped. Figure 15 As shown, the heat sink 220 extends in the in-plane direction away from the inner wall 12B. Figure 16 As shown, no space communicating with the second space 14B is provided inside the heat sink 220. By providing the heat sink 220, the surface area of ​​the heat pipe 210 in contact with the outside air can be increased. Therefore, the heat exchange efficiency between the heat pipe 210 and the outside air is improved, and heat is easily released to the outside air.

[0050] (Effects of Implementation Method 3) (3-1) The heat pipe 210 of embodiment 3 also has a plurality of heat sinks 220 extending from the peripheral wall portion 12.

[0051] With this structure, the heat from the heat pipe 210 can be easily released to the outside air by setting the heat sink 220.

[0052] <Implementation Method 4> Reference Figure 17 and Figure 18 Embodiment 4 of the present invention will be described. The heat pipe 310 of Embodiment 4 includes a heat sink 320, which has a different shape from the heat sink 220 of Embodiment 3. Except for the shape of the heat sink 320, the structure of the heat pipe 310 is the same as that of Embodiment 3, therefore, the description of the components and effects that are the same as those in Embodiment 3 is omitted.

[0053] (Heater 320) like Figure 17 As shown, the heat pipe 310 has multiple heat sinks 320 extending from the peripheral wall portion 12. The heat sinks 320 are plate-shaped. Figure 18 As shown, the heat sink 320 includes a first portion 320A extending from the outer wall 12A, a second portion 320B extending from the inner wall 12B, and a third portion 320C extending from the connecting end 12D and connecting the first portion 320A and the second portion 320B.

[0054] <Implementation Method 5> Reference Figure 19 and Figure 20Embodiment 5 of the present invention will be described. In addition to the heat sink 220 of Embodiment 3, the heat pipe 410 of Embodiment 5 also includes a heat sink 420. Except for the shape of the heat sink 420, the structure of the heat pipe 410 is the same as that of Embodiment 3, therefore, the description of the components and effects that are the same as those in Embodiment 3 is omitted.

[0055] (Heater 420) like Figure 19 As shown, the heat pipe 410 has a plurality of heat sinks 420 formed on the inner side of the peripheral wall portion 12. The heat sinks 420 are plate-shaped. Figure 20 As shown, the heat sink 420 extends from the inner wall 12B of the peripheral wall portion 12 and the second wall 11B of the bottom 111. The heat sink 420 is formed such that its dimension in the first direction D1 decreases as it extends from the peripheral wall portion 12 toward the through hole 116 in the in-plane direction. One side of the heat sink 420 in the first direction D1 ( Figure 20 The end face (above the illustration) becomes part of a mortar-shaped curved surface. In other words, the end face on one side of the heat sink 420 in the first direction D1 is an arc-shaped curve that bends toward the peripheral wall 12 and the bottom 111 when viewed in section.

[0056] (Other implementation methods) The above embodiments 1 to 5 can be implemented in the following variations. The above embodiments 1 to 5 and the following variations can be combined with each other within the scope of technical non-contradiction.

[0057] • In the above embodiment 1, a relay 2 is exemplified as a heating element, but the heating element may also be a resistor, coil, capacitor, fuse, diode, IC (Integrated Circuit), FET (Field Effect Transistor) or other switching element.

[0058] • In the above embodiment 1, the busbar 3 connected to the heating element (relay 2) is shown as the object on which the heat pipe 10 is installed, but the heat pipe may also be directly installed on the heating element.

[0059] • In embodiments 1 to 5 described above, the bottom 11, 111 is circular, but the bottom may also be polygonal or elliptical.

[0060] In embodiments 1 to 5 described above, the peripheral wall portion 12 extends from the outer edge of the bottom portion 11, 111. However, the peripheral wall portion may also extend from the portion of the bottom portion that is closer to the inner edge than the outer edge. In addition, the peripheral wall portion may not be cylindrical.

[0061] • In the above embodiments 1 to 5, the peripheral wall portion 12 extends in a direction orthogonal to the contact surface 13 of the bottom 11, 111 (first direction D1). However, the direction in which the peripheral wall portion extends may not be orthogonal to the contact surface, as long as it intersects the contact surface.

[0062] The heat sink of the present invention may also be different from the heat sinks 220, 320, and 420 in embodiments 3 to 5 described above. For example, the shape, number, and arrangement of the heat sink relative to the peripheral wall portion may be appropriately changed.

[0063] 1. 101: Electrical equipment 2: Relay 2A: Main body 2B: Terminal section 3: Busbar 3A: Connecting part 3B1: Outer surface 3B: Installation Department 3C: Through hole 4: Bolts 5: Nuts 6: Outer shell 6A: Nut storage section 10, 110, 210, 310, 410: Heat pipes 10A: Non-closed body 11, 111: Bottom 11A: First Wall 11B: Second Wall 12: Zhoubi section 12A: Outer wall 12B: Inner wall 12C1: Sealing part 12C2: Opening 12C: Cylindrical section 12D: Connecting end 13: Contact surface 14: Sealed space 14A: First Space 14B: Second Space 15: Working fluid 116: Through hole 116A: Inner wall portion 220, 320, 420: Heatsink 320A: Part 1 320B: Part 2 320C: Part 3 A1: Tilt Angle D1: Direction 1

Claims

1. A heat pipe, disposed inside an electrical device and installed onto an object. The heat pipe has the following features: The bottom has a contact surface that comes into contact with the object. The peripheral wall portion extends from the bottom in a direction intersecting the contact surface; A sealed space is formed inside the bottom and the peripheral wall portion; and The working fluid is configured to occupy a portion of the sealed space.

2. The heat pipe according to claim 1, wherein, It also has a plurality of heat sinks extending from the peripheral wall portion.

3. The heat pipe according to claim 1 or claim 2, wherein, The bottom is circular. The peripheral wall portion extends from the outer edge of the bottom portion.

4. The heat pipe according to claim 1 or claim 2, wherein, A through hole is formed at the bottom for fastening the heat pipe bolt to the object.

5. The heat pipe according to claim 1 or claim 2, wherein, With the electrical equipment positioned on a horizontal plane, the peripheral wall portion is positioned above the bottom.

6. An electrical device comprising: The heat pipe as described in claim 1 or claim 2; Heating components; and The busbar is connected to the heating element and is equipped with the heat pipe.

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