Cooling plate

Abstract

To provide a cooling plate that forms a flow path for coolant without increasing the number of parts. [Solution] The cooling plate A has multiple mating surfaces formed at the boundary where a first opposing surface 11a formed on the first plate member 11 and a second opposing surface 10a formed on the second plate member 10 are superimposed. The multiple mating surfaces include a first mating surface M1 in which cooling channel portions P2 and 21 are formed as cooling channels in each of the two regions that sandwich the mating surface in a direction along the mating surface, and a second mating surface M2 in which at least one of the two regions that sandwich the mating surface in a direction along the mating surface does not have a cooling channel portion formed. The first opposing surface 11a and the second opposing surface 10a are fixed to the second mating surface M2, while at least a part of the first mating surface M1 is not fixed to the first opposing surface 11a and the second opposing surface 10a.

Description

Technical Field

[0001] The present invention relates to a cooling plate.

Background Art

[0002] Patent Document 1 describes a power conversion device in which a heat receiving member having a semiconductor element on its front surface and a plurality of cooling fins on its back surface is overlapped with an inner cover in which a recess for a flow path for accommodating the cooling fins of the heat receiving member is formed, and they are connected by bolts.

[0003] This power conversion device enables cooling of a semiconductor by supplying a refrigerant to the recess for the flow path, and prevents leakage of the refrigerant by sandwiching a sealing member in the contact region between the back surface of the outer periphery of the heat receiving member and the upper surface of the outer periphery of the inner cover.

[0004] Patent Document 2 describes an inverter device in which a front module and a rear module are provided as semiconductor modules on the upper surface of a base plate. The base plate has cooling passages separately formed at positions overlapping these, and connection channels for supplying and discharging a refrigerant to and from each cooling passage are arranged on the lower surface side of the base plate.

[0005] This inverter device has a structure in which the base plate and a lower cover disposed on this lower surface are overlapped. That is, a connection channel is recessed on the upper surface of the lower cover, and the base plate is overlapped in a contact state on the upper surface of this lower cover to enable the flow of the refrigerant in the recessed connection channel. The inverter device described in this Patent Document 2 prevents leakage of the refrigerant from the boundary surface by sandwiching a seal between the base plate and the lower cover.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] Taking hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs) as examples, these vehicles are equipped with a power control system that enables power control, such as controlling the power supplied to the driving motor and charging the vehicle's battery.

[0008] The power control systems installed in vehicles include inverters, DC-DC converters, and chargers (OBCs). These inverters, DC-DC converters, and chargers (OBCs) are heat sources that cause the system temperature to rise, so a configuration that allows for good cooling of these heat sources is required. In particular, for devices that generate a lot of heat during operation, such as high-capacity inverters, efficient heat dissipation is necessary.

[0009] To enable efficient cooling, using a fluid, as described in Patent Documents 1 and 2, allows for effective cooling. However, such a fluid-based configuration requires a flow path to supply the coolant (refrigerant) to the object to be cooled.

[0010] Therefore, a configuration in which multiple plates (a base plate and a bottom cover in the document) are stacked and a flow path is formed at the boundary between these plates can also be considered, as described in Patent Document 2. This configuration does not require the use of pipe material, thus reducing the number of parts and avoiding the inconvenience of fluid leakage due to damage to the pipe material.

[0011] However, a configuration that simply creates a flow path by forming concave grooves at the boundaries of multiple plates is likely to increase the number of parts because it would require seals to prevent fluid leakage from the plate boundaries.

[0012] For these reasons, there is a need for a cooling plate that forms a flow path for the coolant without increasing the number of parts. [Means for solving the problem]

[0013] The characteristic configuration of the cooling plate according to the present invention is a cooling plate capable of cooling an electronic component to be cooled by the flow of a cooling fluid in a cooling channel, comprising a plate member having a plate surface in contact with the electronic component and having a cooling channel formed thereon, wherein the plate member has at least two members, a first plate member and a second plate member, and has a structure in which a first opposing surface formed on the first plate member and a second opposing surface formed on the second plate member are superimposed, and a plurality of mating surfaces are formed that form the boundary between the superimposed first opposing surface and the second opposing surface, wherein the plurality of mating surfaces include a first mating surface in which a cooling channel portion is formed as a cooling channel portion in each of two regions that sandwich the mating surface in a direction along the mating surface, and a second mating surface in which a cooling channel portion is not formed in at least one of the two regions that sandwich the mating surface in a direction along the mating surface, wherein the first opposing surface and the second opposing surface are fixed to the second mating surface, and at least a part of the first mating surface is not fixed to the first opposing surface and the second opposing surface.

[0014] In this configuration, multiple mating surfaces are formed at the boundary where the first opposing surface and the second opposing surface overlap. Of these multiple mating surfaces, the first and second opposing surfaces are not fixed at the first mating surface. Therefore, a small amount of coolant leakage through the cooling channel between the first and second opposing surfaces at the first mating surface is permitted, while eliminating the need for sealing. In contrast, of the multiple mating surfaces, the first and second opposing surfaces are fixed at the second mating surface. Therefore, the first and second plate members are integrated, preventing coolant leakage into areas where a cooling channel is not formed between the first and second opposing surfaces at this second mating surface. In this way, sealing is not required at least for some of the multiple mating surfaces, thus avoiding increased manufacturing processes and higher costs. Consequently, a cooling plate with a cooling channel formed without increasing the number of parts is constructed. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing the schematic configuration of a power control unit, including a cooling plate. [Figure 2] This is a perspective view of the first plate member from below. [Figure 3] This is a plan view of the cooling space. [Figure 4] This is a longitudinal cross-sectional side view of the first upper channel, the supply channel section, and the cooling space. [Figure 5] This is a plan view showing the positional relationship between multiple supply holes and multiple pin fins. [Figure 6] This is a cross-sectional view showing the mating surface between the first plate member and the second plate member. [Modes for carrying out the invention]

[0016] Embodiments of the cooling plate according to the present invention will be described below with reference to the drawings. In these embodiments, various modifications are possible without departing from the scope of the invention, and the invention is not limited to the embodiments described below.

[0017] Hereinafter, embodiments of the present invention will be described based on the drawings. 〔Basic Configuration〕 FIG. 1 shows a power control unit B including a cooling plate A provided in a vehicle (not shown) such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a battery electric vehicle (BEV) that can travel by electric power.

[0018] As shown in FIG. 1, the power control unit B according to the present embodiment includes a cooling plate A and, as electronic components to be cooled by the cooling plate A, a pair of primary power modules 1, a secondary power module 2, a transformer coil 3, a first FET 4, a PFC coil 5, a second FET 6, a secondary coil 7, and an inverter 8 (an example of an electronic component). Note that each of the pair of primary power modules 1, the secondary power module 2, the transformer coil 3, the first FET 4, the PFC coil 5, the second FET 6, and the secondary coil 7 is formed with a predetermined size in the vertical direction, but in this figure, these electronic components are drawn in a plate shape.

[0019] The cooling plate A is composed of plate members 10 and 11. Although details will be described later, the plate members are formed by joining the outer peripheries of the upper plate member 10 (an example of the second plate member) and the lower plate member 11 (an example of the first plate member) that form a pair by welding or the like. This cooling plate A forms a cooling flow path P through which a coolant F shown in FIGS. 3, 4, etc. flows in order to cool the heat generated by a plurality of electronic components constituting the power control unit B. The lower plate member 11 is formed with a supply port Pa at one end of the cooling flow path P and a discharge port Pb at the other end of the cooling flow path P. The coolant F is assumed to be water, but in addition to water, it includes antifreeze mainly composed of ethylene glycol or the like, cooling water such as long-life coolant (LLC) containing propylene glycol or the like, or cooling oil composed of insulating oil such as paraffin. That is, the coolant F is a general term for cooling water and cooling oil.

[0020] The cooling plate A is provided in the vehicle in the posture shown in FIG. 1. Therefore, the vertical relationship of each part of the cooling plate A will be described according to this posture. Hereinafter, the vertical direction is the Z direction, the side and direction where the upper plate member 10 is arranged with respect to the lower plate member 11 are the Z1 side and the Z1 direction, and the side and direction where the lower plate member 11 is arranged with respect to the upper plate member 10 are the Z2 side and the Z2 direction. At this time, the Z2 direction is the direction of gravity.

[0021] As shown in FIG. 1, the upper plate member 10 has a plate surface 10b that contacts (or may be in proximity to) each of the primary power module 1, the secondary power module 2, the transformer coil 3, the first FET 4, the PFC coil 5, the second FET 6, and the secondary coil 7. The plate surface 10b is a part of the first cooling part C1 where the primary power module 1 contacts, the second cooling part C2 where the secondary power module 2 contacts, the third cooling part C3 where the transformer coil 3 contacts, the fourth cooling part C4 where the first FET contacts, the fifth cooling part C5 where the PFC coil contacts, the sixth cooling part C6 where the second FET contacts, and the seventh cooling part C7 where the secondary coil 7 contacts. The lower plate member 11 is a part of the eighth cooling part C8 where the lower surface 15a (an example of a plate surface) of the plate-like body 15 integrated on the Z2 side contacts the inverter 8. These first cooling part C1 to eighth cooling part C8 may also be collectively referred to as the cooling part C.

[0022] The cooling flow path P includes a first flow path part P1, a second flow path part P2, a third flow path part P3, a fourth flow path part P4, a fifth flow path part P5, a sixth flow path part P6, a seventh flow path part P7, and an eighth flow path part P8 for supplying the coolant F in the vicinity of the plurality of cooling parts C. These first flow path part P1 to eighth flow path part P8 may also be collectively referred to as the cooling flow path P.

[0023] In other words, of the multiple cooling channels P, the first channel section P1 to the seventh channel section P7 allow the cooling of electronic components in contact with (or close to) the cooling section C by having the coolant F flow near the heat-exchange plate surface 10b of the upper plate member 10. Specifically, the first channel section P1 to the seventh channel section P7 are formed directly below (on the Z2 side) the plate surface 10b of the upper plate member 10 in each of the first cooling section C1 to the seventh cooling section C7. The thickness of the wall between the plate surface 10b of the upper plate member 10 and the cooling channel P (the distance between the plate surface 10b and the cooling channel P) is preferably as thin as possible while ensuring the necessary strength of the upper plate member 10. This allows the coolant F flowing through the cooling channel P to effectively cool the electronic components. The configuration of the eighth cooling section C8 will be described later.

[0024] With this configuration, the cooling plate A receives coolant F from the supply port Pa, causing the coolant F to flow through the first flow channel P1 to the eighth flow channel P8. In the corresponding first cooling sections C1 to the eighth cooling sections C8, the coolant F removes heat from the electronic components, and after cooling multiple electronic components, it is discharged from the outlet Pb.

[0025] In particular, each of the electronic components, including the primary power module 1, secondary power module 2, transformer coil 3, first FET 4, PFC coil 5, second FET 6, and secondary coil 7, is supported on one or more circuit boards.

[0026] In this configuration, the cooling plate A is positioned such that the primary power module 1, secondary power module 2, transformer coil 3, first FET 4, PFC coil 5, second FET 6, and secondary coil 7 are in contact with or in close proximity to the corresponding first cooling section C1, second cooling section C2, third cooling section C3, fourth cooling section C4, fifth cooling section C5, sixth cooling section C6, and seventh cooling section C7. The positional relationship between the substrate and the upper plate member 10 is set accordingly.

[0027] Furthermore, the cooling plate A may be configured such that a heat conductive sheet or gap filler is sandwiched between the cooling section C for heat exchange to remove heat from the electronic components, and the substrate, electronic components, etc.

[0028] [Plate component] As shown in Figures 1, 2, and 4, the plate members consist of a lower plate member 11 (an example of a first plate member) made of a metal material such as aluminum, and an upper plate member 10 (a second plate member) placed on top of the lower plate member 11. The interface where the first opposing surface 11a of the lower plate member 11 and the second opposing surface 10a of the upper plate member 10 come into contact is called the mating surface. Multiple mating surfaces are formed, and among the multiple mating surfaces, there is a first mating surface M1 in which cooling channel sections (for example, the first upper channel 21 and the second upper channel 22 described later) are formed as cooling channels P in each of the two regions that sandwich the mating surface in a direction along the mating surface, and a second mating surface M2 in which cooling channel sections are not formed in at least one of the two regions that sandwich the mating surface in a direction along the mating surface. The second mating surface M2 has the first opposing surface 11a and the second opposing surface 10a fixed together, while the first mating surface M1 has at least a portion where the first opposing surface 11a and the second opposing surface 10a are not fixed together. The lower plate member 11 has a plate-shaped base portion 11b and a rectangular projection portion 11c that protrudes rectangularly from the surface of the base portion 11b facing the upper plate member 10 (Z2 side). In this embodiment, the lower plate member 11 has the first opposing surface 11a on both the base portion 11b and the rectangular projection portion 11c.

[0029] As shown in Figure 4, the mating surface formed between the first upper flow path 21 and the second flow path section P2 is the first mating surface M1. Also, the mating surface formed between the lower plate member 11 and the upper plate member 10 at the left end position of the same figure is the second mating surface M2. In this embodiment, the first upper flow path 21 (eighth flow path section), which serves as a flow path forming section, is formed in the region on one side of the second mating surface M2 in a direction along the second mating surface M2. The first mating surface M1 is arranged so that the first opposing surface 11a and the second opposing surface 10a are in contact, but tolerances allow for a close proximity state with a small gap formed between them.

[0030] As shown in Figure 4, the cooling channel P is formed by a concave space on at least one of the mating surfaces of the first opposing surface 11a of the lower plate member 11 and the second opposing surface 10a of the upper plate member 10. The concave space is a depression formed on at least one of the first opposing surface 11a and the second opposing surface 10a, and this depression includes grooves, notches, and holes.

[0031] Cooling plate A is assembled by overlapping the first opposing surface 11a formed on the lower plate member 11 and the second opposing surface 10a formed on the upper plate member 10, with a seal in between, and then welding the outer circumference of the joining surface (the outer circumference of cooling plate A in plan view) with a laser beam. The joining surface that is welded in this way with a laser beam is the second joining surface M2. The second joining surface M2 may also be fastened with bolts or bonded with adhesive, not just welded.

[0032] This welding integrates the lower plate member 11 and the upper plate member 10 of the cooling plate A, thereby fixing the position of the cooling channel P formed at the boundary between the first opposing surface 11a and the second opposing surface 10a. Furthermore, since the second mating surface M2 connects and fixes the first opposing surface 11a and the second opposing surface 10a in a tightly fitted state, the phenomenon of a portion of the coolant F flowing through the cooling channel P flowing out along the second mating surface M2 is suppressed. In other words, in the cooling plate A of this embodiment, leakage of coolant F to the outside through the second mating surface M2 can be suppressed, and even if leakage of coolant F between the cooling channel sections (between the first upper channel 21 and the second channel section P2 in this embodiment) through the first mating surface M1 is permitted, the impact is small, thus enabling a configuration that does not use a seal on the first mating surface M1.

[0033] The two plate members 10 and 11 are not limited to those in which the mating surface between the first opposing surface 11a and the second opposing surface 10a is formed as a single plane. For example, in order to make the positions of the mating surfaces in the vertical direction of the cooling channel P different, the cooling plate A may be constructed using multiple plate members with opposing surfaces in different positions in the vertical direction.

[0034] Furthermore, the cooling plate A may be constructed using multiple plate members 10, 11, each having opposing surfaces formed such that multiple mating surfaces with different vertical positions are connected by a mating surface in an oblique position.

[0035] As shown in Figure 4, the cooling plate A has a second flow channel P2 formed in a groove shape on the second opposing surface 10a of the upper plate member 10, and a first upper flow channel 21 (eighth flow channel P8) and a second upper flow channel 22 (eighth flow channel P8) formed in a groove shape. In addition, a cooling space S is formed in the portion of the lower plate member 11 corresponding to the rectangular protrusion 11c, with an opening that is open to the lower surface (Z2 side surface) of the lower plate member 11. As will be described in detail later, the opening of the cooling space S is blocked by a plate-like body 15.

[0036] The second flow channel section P2 is an upstream cooling channel section of the cooling channel P, located upstream of the first upper flow channel 21 and the second upper flow channel 22, while the first upper flow channel 21 and the second upper flow channel 22 are downstream cooling channel sections. These upstream and downstream cooling channel sections are in a positional relationship that does not overlap in a plan view (view in the Z direction), and the phenomenon of coolant F flowing between these flow channels is suppressed. In particular, the temperature of the coolant F in the second flow channel section P2 (upstream cooling channel section) is lower than the temperature of the coolant F in the first upper flow channel 21 (downstream cooling channel section) and the second upper flow channel 22 (downstream cooling channel section). Furthermore, the second flow channel section P2 is located above the first mating surface M1, while the first upper flow channel 21 and the second upper flow channel 22 are located below the first mating surface M1. In other words, the second flow channel section P2 is located above the first upper flow channel 21 and the second upper flow channel 22.

[0037] Even if the first opposing surface 11a and the second opposing surface 10a of the cooling plate A are formed within a predetermined tolerance range during manufacturing, a small gap may be formed between these contact surfaces as shown in Figure 6, and it is possible that a small amount of coolant F may leak into this gap.

[0038] In other words, as shown in Figure 6, a small gap may be formed at the first mating surface M1 between the first opposing surface 11a of the rectangular protrusion 11c on the lower plate member 11 and the second opposing surface 10a of the upper plate member 10. Due to the formation of such a gap, coolant F may leak between the second flow channel P2 and the first upper flow channel 21. When such leakage occurs, the coolant F tends to flow from the upper second flow channel P2 to the lower first upper flow channel 21 due to its own weight. As described above, in this embodiment, the coolant F flowing through the second flow channel P2 is at a lower temperature than the coolant F flowing through the first upper flow channel 21. Therefore, even if leakage occurs, the coolant F flowing through the first upper flow channel 21 is supplied to the cooling space S with its temperature rise suppressed, and thus does not lead to a decrease in cooling performance.

[0039] Similarly, even if, for example, the cooling liquid F flows from the upstream section of the cooling channel P to the downstream section, this does not reduce the cooling performance. In other words, even if a portion of the first opposing surface 11a of the lower plate member 11 and the second opposing surface 10a of the upper plate member 10 are not properly in contact, the flow rate of the cooling liquid F flowing throughout the cooling plate A does not change due to leakage of the cooling liquid F, and the cooling performance does not decrease. Thus, it is not necessary to excessively increase the tolerance between the first opposing surface 11a and the second opposing surface 10a during manufacturing, and it is possible to manufacture the product in a simple process with a configuration that does not require a seal on the mating surface (first mating surface M1 in this embodiment).

[0040] As shown in Figure 6, in the first mating surface M1 formed between the first upper flow path 21 and the second flow path section P2, the front end T of this first mating surface M1, which has a vertical end on the upstream side in the flow direction of the coolant F in the first upper flow path 21, is formed on the lower plate member 11 (first plate member). The lower plate member 11 forms a supply flow path section 23 in an inclined position that directs the coolant F flowing in the first upper flow path 21 diagonally downward. This supply flow path section 23 is formed by five supply holes 23a and is connected to the first upper flow path 21 at a connection point U upstream of the aforementioned front end T at the upper end position in the flow direction of the coolant F.

[0041] In this configuration, the front end T comes into contact with the coolant F flowing through the first upper flow path 21, causing an increase in flow resistance. However, since the connection to the first upper flow path 21 is made at a connection point U upstream of the front end T, it is possible to prevent the front end T from restricting the flow of the coolant F and to suppress the inconvenience of a portion of the coolant F in the first upper flow path 21 leaking through the first mating surface M1.

[0042] The cooling plate A may also have a recovery channel that collects the coolant F leaked through the first mating surface M1 and guides it to the outlet Pb.

[0043] Because this cooling plate A does not use internal pipe material, it can be constructed compactly overall without increasing the number of parts. Furthermore, this cooling plate A is configured to form a cooling channel P by creating a concave space at the mating surface. Therefore, even if the flow rate of the coolant F per unit time is increased according to the specifications, for example, only a design change of enlarging the cross-sectional shape of the concave space is required, and it does not lead to the inconvenience of using large-diameter pipe material, as would be the case with configurations that use pipe material.

[0044] [Inverter cooling structure] As shown in Figure 4, the inverter 8 generates three-phase alternating current from power supplied from a power source (not shown) and controls the supply to the traction motor. During control, it becomes a heat-generating part that generates a large amount of heat.

[0045] The eighth flow path section P8 for cooling the inverter 8 consists of a first upper flow path 21 (an example of a first cooling flow path section), a cooling space S (an example of a second cooling flow path section) located below the first cooling flow path section and downstream in the flow direction of the coolant F, and a supply flow path section 23 that is inclined downward to connect these.

[0046] Figure 2 shows the structure of the eighth flow path section P8 as viewed from below (Z2 side) of the lower plate member 11. Specifically, it shows the five supply holes 23a that constitute the supply flow path section 23, the side wall 25 that forms the cooling space S (see Figure 3), the inverter 8, the plate-like body 15, and the five discharge holes 24a that constitute the discharge flow path section 24. These wall portions are extracted and drawn as perspective views. Therefore, Figure 2 differs from the actual shape of the lower plate member 11 as viewed from below.

[0047] As shown in Figures 3 and 4, the inverter 8 has a flat plate-like body 15 connected to its upper surface to transmit heat from the electronic components. This plate-like body 15 has a plurality of pin fins 16 formed on its surface. The plate-like body 15 and the plurality of pin fins 16 are made of a metal material such as aluminum, which has high thermal conductivity.

[0048] The details of the flow of the coolant F will be described later, but the cooling plate A is cooled when the coolant F flowing through the eighth flow path P8 comes into contact with the plate-shaped body 15 and then with the multiple pin fins 16, thereby removing heat generated by the inverter 8. The eighth cooling section C8 is formed in such a way that the inverter 8 is cooled by the supply of coolant F.

[0049] Furthermore, the multiple pin fins 16 are made of needle-shaped material with a circular cross-section and are formed on the plate-like body 15 in a position perpendicular to the plate surface of the plate-like body 15.

[0050] As shown in Figure 4, the plate-like body 15 is provided on the lower surface side of the lower plate member 11. Specifically, the plate-like body 15 is attached so as to close the opening of the cooling space S formed in the lower plate member 11. The plate-like body 15 is sized to close the opening of the cooling space S. In this way, since the plate-like body 15 forms the cooling space S as a second cooling channel together with the lower plate member 11, it can also be considered as part of the lower plate member 11.

[0051] The plate-like body 15 is fixed to the lower plate member 11 from the bottom side with bolts or the like (not shown), thereby closing the opening of the cooling space S. With the plate-like body 15 fixed in this manner, its surface becomes horizontal, and multiple pin fins 16 are housed vertically inside the cooling space S. An annular seal 17 is fitted into the area surrounding the opening of the cooling space S on the lower surface of the lower plate member 11.

[0052] As shown in Figure 4, the eighth flow path section P8 has a cooling space S, a first upper flow path 21 on the upstream side in the flow direction of the coolant F, and a second upper flow path 22 on the downstream side, with the cooling space S in the middle in a plan view. The eighth flow path section P8 has a supply flow path section 23 arranged in an inclined position between the first upper flow path 21 and the cooling space S, and a discharge flow path section 24 arranged in an inclined position between the cooling space S and the second upper flow path 22. In this embodiment, the cooling space S corresponds to "another cooling flow path section located downstream in the flow direction of the coolant from the downstream cooling flow path section."

[0053] The first upper flow channel 21 and the second upper flow channel 22 are formed as a concave space in the second opposing surface 10a of the upper plate member 10 and as a groove-shaped concave space in the first opposing surface 11a of the lower plate member 11, respectively, on one side of the first mating surface M1 along the first mating surface M1. These first upper flow channel 21 and second upper flow channel 22 are positioned higher than the cooling space S.

[0054] In other words, the supply channel section 23 communicates with the first upper channel section 21, which is formed as a groove-shaped concave space in the second opposing surface 10a, on its upstream side, and with the downstream end communicating with the cooling space S. Similarly, the discharge channel section 24 communicates with the cooling space S on its upstream end, and with the downstream end communicating with the second upper channel section 22, which is formed as a groove-shaped concave space in the second opposing surface 10a.

[0055] Furthermore, the second flow channel P2 is formed as a groove-shaped recessed space that opens to the second opposing surface 10a of the upper plate member 10, on the upper side of the cooling space S and on the opposite side of the first mating surface M1 from the first upper flow channel 21 and the second upper flow channel 22. This second flow channel P2 is positioned so as not to communicate with the first upper flow channel 21 and the second upper flow channel 22.

[0056] In cooling plate A, the temperature of the coolant F flowing through the first upper channel 21 is lower than the temperature of the coolant F flowing through the cooling space S, the discharge channel 24, and the second upper channel 22.

[0057] As described above, the supply channel section 23 is composed of a plurality (five) of supply holes 23a formed linearly in an inclined position to supply coolant F from the first upper channel 21 to the cooling space S. The plurality (five) of supply holes 23a are each formed with the same inner diameter. The discharge channel section 24 is composed of a plurality (five) of discharge holes 24a formed linearly in an inclined position to discharge the coolant F that has flowed into the cooling space S to the second upper channel 22.

[0058] In particular, the multiple discharge holes 24a and the multiple supply holes 23a that constitute the discharge channel section 24 are formed in a common number and have a common shape in which the multiple holes are arranged coaxially in a plan view.

[0059] The five supply holes 23a and discharge holes 24a are arranged in parallel in a direction perpendicular to the direction in which the coolant F flows, and are drilled in the lower plate member 11 so that each is parallel to the others.

[0060] As shown in Figure 4, when the center of the flow path in the supply hole 23a is defined as the supply-side centerline L1 and the center of the flow path in the discharge hole 24a is defined as the discharge-side centerline L2, in a side view, the supply-side inclination angle θ1 of the supply-side centerline L1 with respect to the plate surface of the plate-like body 15 and the discharge-side inclination angle θ2 of the discharge-side centerline L2 with respect to the plate surface of the plate-like body 15 are set to equal values.

[0061] Furthermore, the supply-side inclination angle θ1 and the discharge-side inclination angle θ2 do not need to be set to the same value; they may be different values. The discharge channel section 24 does not need to be composed of multiple discharge holes 24a; for example, it can be formed as a single simple hole with the same width as the cooling space S. Also, even when the cooling plate A is configured with multiple discharge holes 24a to form the discharge channel section 24, the number of discharge holes may be different from that of the supply holes 23a.

[0062] The inverter 8 has a configuration in which multiple power control elements (electronic components) such as MOSFETs are supported on the underside of the plate-like body 15 while mounted on a substrate or the like. As a result, when power is controlled by the inverter 8, heat from the multiple power control elements is transferred to the plate-like body 15 by thermal conduction. In addition, a thermal conductive sheet may be interposed between the plate-like body 15 and the electronic components (which may also be a substrate) to ensure good thermal conduction.

[0063] As shown in Figures 3 and 5, the first upper channel 21 supplies coolant F to the supply channel 23 after passing through a curved channel section in a plan view. Furthermore, this cooling plate A makes the sum of the cross-sectional areas of the multiple (five) supply holes 23a smaller than the cross-sectional area of ​​the first upper channel 21 located upstream near the supply channel 23. This slightly increases the pressure of the coolant F in the supply holes 23a, thereby increasing the flow velocity, and at the same time, it averages the flow rate of the coolant F flowing through each of the multiple (five) supply holes 23a.

[0064] In other words, the first upper flow path 21 located upstream of the supply flow path section 23 is curved in plan view, so the flow velocity of the coolant F differs between the center of curvature of the curved flow path and the area outside of it, resulting in a different flow rate of coolant F per unit time in the width direction of the flow path. To address this, by setting the cross-sectional area of ​​the flow path, the pressure acting on the upstream ends of the multiple (five) supply holes 23a is slightly increased, thereby achieving uniformity of the flow rate of coolant F per unit time in each of the multiple (five) supply holes 23a.

[0065] As shown in Figure 4, the cooling space S is rectangular in side view when the lower opening is closed by the plate-like body 15. In addition, the downstream ends of the multiple supply holes 23a are in communication with the corner portions of the upper end of the cooling space S.

[0066] As shown in Figure 4, in a side view, the point where the supply-side center line L1 intersects the upper surface of the plate-like body 15 (the intersection point) is referred to as the high-temperature region H. This high-temperature region H is located on the plate surface of the plate-like body 15, where the temperature is more likely to rise than other plate surfaces due to the heat from the inverter 8.

[0067] By setting the orientation of the supply hole portion 23a in this manner, efficient cooling becomes possible by directly supplying the coolant F to the high-temperature region H of the plate-like body 15. Furthermore, since the supply hole portion 23a connects to the cooling space S in this orientation, the downstream end of the supply hole portion 23a is located at a set distance above the lower surface of the cooling space S.

[0068] As mentioned above, since the orientation of the discharge hole 24a is the same as that of the supply hole 23a (symmetrical orientation in side view), the downstream end of the discharge hole 24a is located at a set distance above the bottom wall of the cooling space S (the surface on which the pin fins 16 are formed).

[0069] Furthermore, the connection of the supply hole 23a and the discharge hole 24a at these positions avoids interference with the seal 17. Note that the region of the plate-like body 15 where the temperature rises due to the heat of the inverter 8 is not limited to one location; if there are multiple such regions, one of them is designated as the high-temperature region H at its intersection with the supply-side centerline L1.

[0070] As shown in Figures 3 and 5, the multiple pin fins 16 are arranged in parallel at set intervals in the width direction perpendicular to the direction in which the coolant F flows, in a plan view (view in the Z direction), and are also arranged in a staggered pattern with a positional relationship that is set interval in the direction in which the coolant F flows. Of the multiple pin fins 16, those located at the outer end in the width direction are spaced a set distance apart on the inside of the side wall 25 in the width direction of the cooling space S.

[0071] As shown in Figure 5, among the multiple supply holes 23a, the opening of the supply hole 23a located at the center of the width direction of the cooling space S (located in the central region) is positioned opposite the center midway between adjacent pin fins 16 in the width direction, among the multiple pin fins 16 located at the upstream end of the multiple pin fins 16.

[0072] In other words, the supply channel section 23 is configured such that the central channel center Xc of the supply channel section 23 located in the center in the width direction is in the central region of a pair of adjacent pin fins 16 in the width direction (at a position half the distance between the pair of pin fins 16). This relative positional relationship between the opening of this supply channel section 23a and the pin fins 16 is set. As a result, the coolant F supplied from the opening of this supply channel section 23a flows between the pair of pin fins 16 corresponding to this opening.

[0073] Furthermore, among the multiple supply holes 23a, the openings of the supply holes 23a located at both ends in the width direction of the cooling space S are positioned opposite the multiple pin fins 16 located at the upstream end of the multiple pin fins 16. This sets the relative positional relationship so that the coolant F is directly supplied to those pin fins 16.

[0074] In other words, the relative positional relationship between the supply holes 23a and the pin fins 16 is set such that the end flow path centers Xs of the supply holes 23a located at both ends in the width direction intersect with the centers of the needle-shaped materials constituting the pin fins 16 in a plan view. As a result, the coolant F supplied from the opening of the supply hole 23a flows so as to collide with the corresponding pin fins 16.

[0075] In this way, the positional relationship between the multiple supply holes 23a and the multiple pin fins 16 is set, so that the coolant F supplied from the supply hole 23a located in the central region in the width direction of the cooling space S along the central flow path center Xc passes between the pin fins 16 located at the upstream end of the multiple pin fins 16, flows smoothly without stagnation at the upper end of the cooling space S in the supply direction of the coolant F, and allows for an increase in the area in contact between the coolant F and the pin fins 16.

[0076] In contrast, the coolant F supplied from the supply holes 23a located at both ends in the width direction of the cooling space S, along the center Xs of the end flow path, comes into contact with the pin fins 16 located at the upstream end of the multiple pin fins 16, separating into outer and inner portions in the width direction of the cooling space S, with a portion flowing in contact with the side wall 25 of the cooling space S.

[0077] The coolant F that flows into the cooling space S in this manner passes through multiple discharge holes 24a of the discharge channel section 24 and is discharged from the discharge port Pb.

[0078] [Effects of the Embodiment] Cooling plate A cools electronic components by supplying coolant F to its internal cooling channel P, thereby removing heat from the electronic components at the heat exchange plate surfaces 10b and 15a and achieving cooling of each electronic component.

[0079] Cooling plate A is configured by overlapping a lower plate member 11 and an upper plate member 10, and forming a cooling channel P at the joint surface between them. For example, by forming grooves or holes along the joint surface between the lower plate member 11 and the upper plate member 10, it is possible to create a cooling channel P by overlapping the lower plate member 11 and the upper plate member 10.

[0080] For example, compared to a configuration in which a flow path is created inside by processing such as drilling holes in a metal block, the cooling plate A, which consists of a lower plate member 11 and an upper plate member 10 stacked on top of each other, can form a cooling flow path P of a complex shape with relatively easy processing.

[0081] Multiple mating surfaces are formed at the boundary where the first opposing surface 11a and the second opposing surface 10a overlap. Of these multiple mating surfaces, at least a portion of the first mating surface M1 is configured so that the first opposing surface 11a and the second opposing surface 10a are not fixed together. Therefore, leakage of coolant F between the second flow path P2 and the first upper flow path 21 and the second upper flow path 22, passing between the first opposing surface 11a and the second opposing surface 10a at the first mating surface M1, is permitted without requiring a seal. Furthermore, of the multiple mating surfaces, the first opposing surface 11a and the second opposing surface 10a are fixed together at the second mating surface M2, thereby integrating the lower plate member 11 and the upper plate member 10 and preventing leakage of coolant F to the outside through the space between the first opposing surface 11a and the second opposing surface 10a at this second mating surface M2.

[0082] In this way, the cooling plate A, which is constructed by overlapping the lower plate member 11 and the upper plate member 10, can be configured as a second mating surface M2 by overlapping the outer peripheral portions of the lower plate member 11 and the upper plate member 10 in a plan view and welding and fixing the outer peripheral portions. Furthermore, by arranging multiple first mating surfaces M1 inside this outer peripheral region, even if coolant F leaks at the first mating surface M1, the cooling performance will not be significantly reduced.

[0083] In the cooling plate A, in the eighth flow path section P8 that cools the inverter 8, the sum of the flow path cross-sectional areas of the multiple supply holes 23a that constitute the supply flow path section 23 is set to be smaller than the flow path cross-sectional area of ​​the first upper flow path 21 located upstream of the supply flow path section 23.

[0084] As a result, when the coolant F is supplied from the first upper flow path 21 to the supply flow path section 23, the flow velocity of the coolant F in the supply hole section 23a is increased, and at the same time, the flow rate of the coolant F per unit time flowing through each of the multiple (five) supply hole sections 23a is averaged. Consequently, if we consider the widthwise space of the cooling space S, an equal amount of coolant F is supplied to each space, eliminating any bias in cooling performance in the widthwise direction.

[0085] Furthermore, since the supply channel section 23 is composed of multiple supply holes 23a in an inclined position that are lower towards the downstream side, the flow velocity of the coolant F increases due to its own weight, suppressing the reduction in flow velocity when it comes into contact with the multiple pin fins 16 in the cooling space S.

[0086] The eighth flow channel P8 allows the coolant F, which is sent out from the supply hole 23a located in the central region in the width direction of the supply flow channel 23 among the multiple supply holes 23a, to flow through the multiple pin fins 16 without causing a decrease in flow velocity, thereby suppressing the stagnation of the coolant F inside the cooling space S.

[0087] Furthermore, the eighth flow channel P8 actively brings the coolant F, which is sent out from the supply holes 23a located at both ends in the width direction of the supply flow channel 23, into contact with the pin fins 16 located at the upstream end of the multiple pin fins 16. This diverts the coolant F, and by bringing a portion of the diverted coolant F into contact with the inner surface of the side wall 25 of the cooling space S, the cooling efficiency of the inverter 8 is increased.

[0088] In the plate-shaped body 15, the inverter 8 can be efficiently cooled by linearly supplying the coolant F along the supply-side center line L1 shown in Figure 4 to the high-temperature region H on the plate surface where the temperature of the plate surface is higher than the temperature of other plate surfaces due to heat transmitted from the electronic components.

[0089] [Another embodiment] The present invention may also be configured as follows, in addition to the embodiments described above (parts having the same functions as the embodiments are given the same numbers and reference numerals as the embodiments).

[0090] (a) The cooling plate A may be made by stacking three or more plate members. The plate members may also be made of resin material. The cooling channel P formed in the cooling plate A is not limited to the shape described in the embodiment, and can be set to a shape corresponding to the specifications, for example.

[0091] (b) In the embodiment, the cooling channel P is formed as a single channel between the supply port Pa and the discharge port Pb, but for example, a branching point may be formed in a part of the cooling channel P, and the coolant F may be configured to flow in a branched manner. In this configuration in which a branching point is formed in a part of the cooling channel P, it is also possible to set the shape of the groove portion so that the channel formed in the groove shape (as a concave space) on the mating surface is branched at the mating surface.

[0092] (c) As partially described in the embodiment, when a configuration is adopted in which mating surfaces are formed at different positions (heights) in the vertical direction, for example, the upstream portion of the cooling channel P may be placed on the mating surface at the higher position, and the downstream portion of the cooling channel P may be placed on the mating surface at a lower position. By arranging in this way, if coolant F flows to the mating surface due to leakage, the coolant F can flow smoothly from the cooling channel P at the higher position to the cooling channel P at the lower position, and the reverse is less likely to occur.

[0093] (d) Instead of the pin fins 16, it is also possible to use multiple plate-shaped fins or corrugated plate material as fins. When multiple fins are formed on the plate-shaped body 15, the relative positional relationship between the position of each fin and the multiple supply holes 23a can be set arbitrarily.

[0094] Thus, while the fins are not limited to a specific shape, it is desirable that they be arranged at intervals set in the width direction within the cooling space S. Furthermore, the arrangement of multiple fins is not limited to a staggered arrangement; they may be arranged at intervals set in the width direction and the flow direction of the coolant F, or multiple fins may be arranged randomly in a plan view.

[0095] (e) The multiple supply holes 23a constituting the supply channel section 23 are not limited to being arranged in a single row in the width direction, but may be arranged in multiple stages vertically, for example. The cross-sectional areas of the supply channels of the multiple supply holes 23a may also be different. Furthermore, the supply-side inclination angles θ1 of all the multiple supply holes 23a do not need to be the same, and the supply-side inclination angles θ1 of the multiple supply holes 23a may be different.

[0096] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, provided that no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention.

[0097] In the embodiment described above, the following configuration can be envisioned. (1) A cooling plate A capable of cooling electronic components (secondary power module 2 and inverter 8) by the flow of a cooling liquid F through a cooling channel P, comprising a plate member having a plate surface in contact with the electronic components (secondary power module 2 and inverter 8) and having a cooling channel P formed thereon, wherein the plate member has at least two members, a first plate member (lower plate member 11) and a second plate member (upper plate member 10), and the first opposing surface 11a formed on the first plate member (lower plate member 11) and the second opposing surface 10a formed on the second plate member (upper plate member 10) overlap A cooling plate having a combined structure, wherein multiple mating surfaces are formed at the boundary where a first opposing surface 11a and a second opposing surface 10a are superimposed, and the multiple mating surfaces include a first mating surface M1 in which cooling channel portions as cooling channels P are formed in each of two regions that sandwich the mating surface in a direction along the mating surface, and a second mating surface M2 in which cooling channels P are not formed in at least one of the two regions that sandwich the mating surface in a direction along the mating surface, wherein the first opposing surface 11a and the second opposing surface 10a are fixed to the second mating surface M2, and at least a portion of the first mating surface M1 is a cooling plate in which the first opposing surface 11a and the second opposing surface 10a are not fixed.

[0098] According to this, multiple mating surfaces are formed at the boundary where the first opposing surface 11a and the second opposing surface 10a are superimposed. Of these multiple mating surfaces, at least a portion of the first mating surface M1 is configured so that the first opposing surface 11a and the second opposing surface 10a are not fixed together. As a result, leakage of the coolant F through the cooling flow channels (between the second flow channel P2 and the eighth flow channel P8 (first upper flow channel 21 and second upper flow channel 22)) between the first opposing surface 11a and the second opposing surface 10a at the first mating surface M1 is permitted, while eliminating the need for sealing. Furthermore, of the multiple mating surfaces, the first opposing surface 11a and the second opposing surface 10a are fixed together at the second mating surface M2. Therefore, the lower plate member 11 (first plate member) and the upper plate member 10 (second plate member) are integrated, preventing leakage of the coolant F into the area (outside) where a cooling channel is not formed between the first opposing surface 11a and the second opposing surface 10a on the second mating surface M2. In this way, sealing is not required on at least some of the multiple mating surfaces, thus avoiding an increase in manufacturing processes and costs. Consequently, a cooling plate with a cooling channel formed without increasing the number of parts can be realized.

[0099] (2) In the cooling plate A of (1), it is preferable that one cooling channel P includes two cooling channel sections (second channel section P2, eighth channel section P8 (first upper channel section 21 and second upper channel section 22)) that sandwich the first mating surface M1, and that one of the two cooling channel sections is the upstream cooling channel section (second channel section P2), and the other cooling channel section is the downstream cooling channel section (eighth channel section P8 (first upper channel section 21 and second upper channel section 22)) that is located downstream in the flow direction of the coolant F compared to the other cooling channel section.

[0100] According to this, the two cooling channel sections (second channel section P2 and eighth channel section P8 (first upper channel 21 and second upper channel 22)) flanking the first mating surface M1 are included in a single cooling channel P. Therefore, even if coolant F leaks between the two cooling channel sections (between the second channel section P2 and the eighth channel section P8 (first upper channel 21 and second upper channel 22)) through the first mating surface M1, it does not change the flow rate of coolant F throughout the cooling plate A, and thus does not worsen the cooling performance.

[0101] (3) In the cooling plate A of (2), the upstream cooling channel section (second channel section P2) is located above the first mating surface M1, the downstream cooling channel section (eighth channel section P8) is located below the first mating surface M1, and it is preferable that the temperature of the coolant flowing through the upstream cooling channel section (second channel section P2) is lower than the temperature of the coolant F flowing through the downstream cooling channel section (eighth channel section P8).

[0102] According to this, for example, even if the coolant F flows from either the upstream cooling channel (second channel P2) or the downstream cooling channel (eighth channel P8 (first upper channel 21 and second upper channel 22)) through the first mating surface M1 and flows into the other channel, the flow rate of the coolant F throughout the cooling plate A will not change, and the cooling performance will not deteriorate. Also, the upstream cooling channel (second channel P2) is located above the first mating surface M1 than the downstream cooling channel (eighth channel P8). Therefore, leakage of the coolant F through the first mating surface M1 is more likely to occur from the upstream cooling channel (second channel P2) to the downstream cooling channel (eighth channel P8). However, with this configuration, the coolant F flowing through the upstream cooling channel (second channel P2) is at a lower temperature than the coolant F flowing through the downstream cooling channel (eighth channel P8). Therefore, the temperature rise of the coolant F flowing through the downstream cooling channel (eighth channel P8) can be suppressed, and the decrease in cooling performance can be suppressed.

[0103] In the cooling plate A of (4)(3), the cooling channel P further has a supply channel section 23 that is inclined downward to connect the downstream cooling channel section (the first upper channel section 21 of the eighth channel section P8) with another cooling channel section (cooling space S) located downstream of the said downstream cooling channel section (the first upper channel section 21 of the eighth channel section P8) in the direction of coolant F flow, and it is preferable that the supply channel section 23 is connected to the upstream side in the direction of coolant F flow from the front end T of the first mating surface M1, which is the upstream end in the direction of coolant F flow.

[0104] According to this configuration, it becomes possible to supply coolant F from the downstream cooling channel section (the first upper channel 21 of the eighth channel section P8) to another cooling channel section (cooling space S) located downstream in the flow direction via the inclined supply channel section 23. In this case, the supply channel section 23 is connected upstream in the flow direction of the coolant F from the front end T, which is the upstream end in the flow direction of the coolant F, of the first mating surface M1 in the downstream cooling channel section (the first upper channel 21 of the eighth channel section P8). In this configuration, the coolant F flowing in the downstream cooling channel section (the first upper channel 21 of the eighth channel section P8) is likely to come into contact with the front end T, leading to an increase in flow resistance. However, since the supply channel section 23 is connected upstream of this front end T, the coolant F flowing in the downstream cooling channel section (the first upper channel 21 of the eighth channel section P8) is likely to flow into the downwardly inclined supply channel section 23. Therefore, leakage of the coolant F into the upstream cooling channel (second channel P2) through the first mating surface M1 is unlikely. [Industrial applicability]

[0105] This invention can be used in cooling plates. [Explanation of symbols]

[0106] 10: Second plate member, 10a: Second opposing surface, 11: First plate member, 11a: First opposing surface, 21: First upper flow path (downstream cooling flow path section), 22: Second upper flow path (downstream cooling flow path section), 23: Supply flow path section, A: Cooling plate, F: Coolant, P: Cooling flow path, P2: Second flow path section (upstream cooling flow path section), P8: Eighth flow path section (downstream cooling flow path section), M1: First mating surface, M2: Second mating surface, S: Cooling space (other cooling flow path section), T: Front end

Claims

1. A cooling plate capable of cooling an electronic component to be cooled by the flow of a cooling liquid through a cooling channel, The plate member has a plate surface in which the electronic component makes contact, and the cooling channel is formed therein. The plate member has at least two members, a first plate member and a second plate member, and has a structure in which a first opposing surface formed on the first plate member and a second opposing surface formed on the second plate member are superimposed. Multiple mating surfaces are formed that form the boundary between the first opposing surface and the second opposing surface, The plurality of mating surfaces include a first mating surface in which cooling channel portions are formed as cooling channels in each of two regions that sandwich the mating surface in a direction along the mating surface, and a second mating surface in which the cooling channel portions are not formed in at least one of the two regions that sandwich the mating surface in a direction along the mating surface. The second mating surface is a cooling plate on which the first opposing surface and the second opposing surface are fixed, and at least a portion of the first mating surface is not fixed to the first opposing surface and the second opposing surface.

2. One of the cooling channels includes two cooling channel sections that sandwich the first mating surface, The cooling plate according to claim 1, wherein one of the two cooling channel sections is an upstream cooling channel section, and the other cooling channel section is a downstream cooling channel section located downstream of the other cooling channel section in the flow direction of the coolant.

3. The upstream cooling channel section is located above the first mating surface, and the downstream cooling channel section is located below the first mating surface. The cooling plate according to claim 2, wherein the temperature of the coolant flowing in the upstream cooling channel is lower than the temperature of the coolant flowing in the downstream cooling channel.

4. The cooling channel further includes a supply channel section that is inclined downward to connect the downstream cooling channel section with another cooling channel section located downstream of the downstream cooling channel section in the direction of coolant flow. The cooling plate according to claim 3, wherein the supply channel portion is connected to the upstream side in the flow direction of the coolant from the front end of the first mating surface, which is the upstream end in the flow direction of the coolant.

Images