JP2014013848A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger having a housing with excellent radiation performance and productivity.SOLUTION: A heat exchanger 1 includes: a bottom plate 20; multiple cooling pipes 3 arranged on one surface of the bottom plate 20; and joints 5 forming each one of contact ports 52 by collecting multiple flow passages at both ends of the cooling pipes 3. The cooling pipes 3 include heat sinks 4 disposed in openings 30 arranged on the opposite side of the bottom plate 20. Each heat sink 4 includes: a base 40 having a heat generator mounting surface 400; and radiation fins 41 erected from the opposite side surface of the heat generator mounting surface 400 in the base 40. The bases 40 are joined with inner peripheral edges of the openings 30 of the cooling pipes 3 while the radiation fins 41 are inserted to the cooling pipes 3. The bottom plate 20 has an outer peripheral flange 24 extending outward from the outer peripheral parts of the cooling pipes 3. A housing 2 including the bottom plate 20, the cooling pipes 3, and the joints 5 is integrally formed by die casting.

Description

  The present invention relates to a heat exchanger for cooling a heating element such as an IGBT (Insulated Gate Bipolar Transistor).

  Inverter units are used as electronic components for controlling drive motors in hybrid vehicles that are now widely used and electric vehicles that are attracting attention as next-generation environmentally-friendly vehicles. The inverter unit is provided with an IGBT that performs a switching function. The IGBT generates heat during use, but it cannot perform its original function at a high temperature. Therefore, the IGBT needs to be sufficiently cooled. On the other hand, the characteristics required of IGBTs such as a high-speed switching function are increasing year by year, and the amount of heat generation is also increasing along with this, and improvement of the function of the system for cooling the IGBTs is increasingly regarded as important.

  It is effective to use a heat sink for cooling the IGBT. The heat sink is manufactured using a material having good thermal conductivity, and has a function of dissipating heat from the heating elements arranged in contact with each other by increasing the surface area per unit area. As forms for increasing the surface area, there are various forms such as a fin type and a corrugated type.

  Further, in order to further improve the heat dissipation performance, a liquid cooling type cooling system that efficiently dissipates heat using the coolant as a medium is known by arranging fin portions of the heat sink in a flow path through which the coolant flows. For example, Patent Documents 1 and 2 propose a heat exchanger in which a flow path through which a coolant flows and an inlet and an outlet of the coolant are formed in a lower case that receives an upper case as a heat sink. These heat exchangers are configured by joining the upper case and the lower case in a state where the fin portion of the heat sink is disposed in the flow path portion of the lower case. The heat exchanger manufactured in this manner exhibits its cooling function by placing a heating element such as IGBT in contact with the surface of the upper case opposite to the fin portion.

  In addition, a heat exchanger for cooling an in-vehicle IGBT is required to be small and light as well as heat dissipation performance. In order to meet such demands, there is a heat exchanger that employs an aluminum material.

JP 2009-135477 A JP 2010-69503 A

  However, since the heat exchanger disclosed in Patent Document 1 and Patent Document 2 meanders the flow path formed in the lower case and arranges the plurality of heat radiation fins, the flow path length is long. For this reason, there is a risk that the pressure loss becomes large, or the heat radiation performance on the downstream side of the flow path is lower than that on the upstream side. As a result, the heat dissipation performance may be reduced.

  This invention is made | formed in view of said background, Comprising: It aims at providing the heat exchanger which has a housing part excellent in heat dissipation performance and productivity.

One embodiment of the present invention includes a flat bottom plate portion, a plurality of cooling pipe portions that form a plurality of flow paths disposed on one surface of the bottom plate portion, and both ends of the plurality of cooling pipe portions. A heat exchanger having a joint part that collects a plurality of the flow paths to form one communication port,
The cooling pipe portion has a heat sink portion disposed in an opening provided on the opposite side of the bottom plate portion,
The heat sink portion includes a plate-like base portion having a heating element mounting surface for mounting the heating element, and a radiation fin portion standing on the surface of the base portion opposite to the heating element mounting surface. And the base part and the inner peripheral edge of the opening of the cooling pipe part are joined in a state where the radiating fin part is inserted into the cooling pipe part,
The bottom plate portion has an outer peripheral collar portion extending outward from an outer peripheral portion of the cooling pipe portion,
A housing part comprising the bottom plate part, the cooling pipe part and the joint part is integrally formed by die-casting (Claim 1).

  The heat exchanger includes the plurality of cooling pipe sections and a joint section that collects the plurality of flow paths at both ends of the plurality of cooling pipe sections to form one connection port. This eliminates the need to meander the flow path and facilitates shortening the flow path length, so the heat exchanger can easily reduce pressure loss, and the upstream and downstream sides of the flow path. The difference in heat dissipation between them is small. As a result, the heat exchanger has excellent heat dissipation performance. In addition, the heat exchanger can easily use the plurality of cooling pipe portions simply by connecting a pair of communication ports arranged at both ends of the flow path to the path of the cooling medium.

  The bottom plate portion has a flat plate shape, and has an outer peripheral collar portion extending outward from the outer peripheral portion of the cooling pipe portion. Thereby, when assembling the heat exchanger in various machines, devices, etc., the shape of the arrangement space can be simplified, and the heat exchanger can be fixed using the outer peripheral collar portion. Thereby, the assembly | attachment property of the said heat exchanger can be improved.

  Moreover, the housing part which consists of the said cooling pipe part, the said baseplate part, and the said joint part is integrally formed by die-casting. For this reason, it is not necessary to provide a step of separately preparing and joining the outer peripheral flange portion, the joint portion, and the like, and the housing portion is excellent in productivity.

  As mentioned above, according to the said aspect, the heat exchanger which has a housing part excellent in heat dissipation performance and productivity can be provided.

The perspective view of the heat exchanger in an Example. The components expanded view of the heat exchanger in an Example. The top view of the housing part of the heat exchanger in an Example. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3.

In the heat exchanger, the inner peripheral edge of the opening of the cooling pipe part and the base part of the heat sink part may be joined by friction stir welding (Claim 2).
In this case, it becomes easy to join the base portion and the inner peripheral edge of the opening so that there is no unjoined portion. Therefore, it is possible to prevent leakage of the cooling medium from the joint portion between the base portion and the cooling pipe portion. Further, since it is not necessary to use a joining member such as a brazing material for joining the base portion and the inner peripheral edge of the opening, the member cost can be easily reduced. In addition, a well-known joining method, such as welding and joining by an adhesive agent, can also be employed for joining the base portion and the cooling pipe portion.

In addition, two of the cooling pipe portions are provided substantially in parallel, and are connected to the joint portion that collects two flow paths at one of the connection ports at both ends thereof. You may arrange | position in the center position equidistant from one said cooling pipe part (Claim 3).
In this case, the cooling medium flowing in the flow path is easily distributed evenly to each flow path by the joint portion. Therefore, it becomes easy to equalize the heat dissipation performance in each of the flow paths, and the cooling design is facilitated.

  An embodiment of the heat exchanger will be described with reference to FIGS. As shown in FIG. 2, the heat exchanger 1 includes a flat bottom plate portion 20, a plurality of cooling pipe portions 3 that form a plurality of flow paths disposed on one surface of the bottom plate portion 20, and a plurality of cooling tubes. At both ends of the tube portion 3, there is a joint portion 5 that collects a plurality of flow paths and forms one connection port 52. The cooling pipe part 3 has the heat sink part 4 arrange | positioned at the opening part 30 provided in the other side of the baseplate part 20, as shown in FIG.1 and FIG.2. As shown in FIG. 2, the heat sink portion 4 is erected from a plate-like base portion 40 having a heating element mounting surface 400 for mounting a heating element, and a surface of the base portion 40 opposite to the heating element mounting surface 400. The radiating fin portion 41 is provided. Further, as shown in FIG. 4, the heat sink part 4 is joined to the base part 40 and the inner peripheral edge of the opening 30 of the cooling pipe part 3 in a state in which the radiating fin part 41 is inserted into the cooling pipe part 3. As shown in FIGS. 1 and 3, the bottom plate portion 20 has an outer peripheral flange portion 24 that extends outward from the outer peripheral portion of the cooling pipe portion 3. And the housing part 2 which consists of the baseplate part 20, the cooling pipe part 3, and the joint part 5 is integrally formed by die-casting.

  As shown in FIG. 3, the bottom plate portion 20 has a substantially rectangular shape when viewed from the thickness direction. A plurality of bolt insertion holes 240 penetrating in the thickness direction are formed in the outer peripheral collar portion 24 of the bottom plate portion 20. Accordingly, the heat exchanger 1 is configured to be fastened to various machines and devices using the bolt inserted into the bolt insertion hole 240. Hereinafter, the thickness direction of the bottom plate portion 20 is referred to as “height direction Z”.

  As shown in FIG. 1, two cooling pipe portions 3 are formed on one surface of the bottom plate portion 20. As shown in FIG. 4, the cooling pipe portion 3 has a substantially rectangular tube shape, and one of its wall surfaces is constituted by a bottom plate portion 20. In addition, as shown in FIG. 3, the two cooling pipe portions 3 are arranged in parallel with each other with the longitudinal direction directed to the short side of the bottom plate portion 20 and at intervals in the direction perpendicular to the longitudinal direction. Yes. Hereinafter, the longitudinal direction of the cooling pipe portion 3 is referred to as “longitudinal direction X”, and the arrangement direction of the cooling pipe portions 3 is referred to as “width direction Y”.

  Further, as shown in FIG. 3, joint portions 5 are respectively disposed at both ends of the cooling pipe portion 3. The joint portion 5 includes a substantially cylindrical communication port 52 and a distribution pipe unit 53 that connects the communication port 52 and the two cooling pipe units 3. As shown in FIG. 3, the communication port 52 protrudes outward in the longitudinal direction X from the edge of the bottom plate portion 20, and its central axis is substantially the center of the two cooling pipe portions 3 in the width direction Y. They are arranged to match. In addition, the distribution pipe part 53 is formed on the surface of the bottom plate part 20 on the side having the cooling pipe part 3, and each of the two cooling pipe parts 3 from the end of the communication port 52 on the cooling pipe part 3 side. Branches toward the end. Thereby, the joint part 5 is arrange | positioned in the center position 201 equidistant from the two cooling pipe parts 3, as shown in FIG.

  Further, between the two cooling pipe portions 3, as shown in FIGS. 4 and 5, the outer peripheral surfaces of the two cooling pipe portions 3 facing each other, the outer peripheral surface of the joint portion 5, and the bottom plate portion 20. The recessed part 21 which becomes is formed.

  Further, as shown in FIG. 2, a substantially rectangular opening 30 is formed on the wall surface of each cooling pipe portion 3 opposite to the bottom plate portion 20. Further, as shown in FIG. 4, a stepped portion 31 is formed on the inner peripheral edge of the opening 30, the height of which is lower than that of the outer side of the opening 30. Then, the heat radiation fin portion 41 of the heat sink portion 4 is inserted into the opening 30, and the periphery of the base portion 40 is fitted to the step portion 31. Thereby, the heating element mounting surface 400 of the heat sink portion 4 and the outer peripheral surface of the cooling pipe portion 3 on the outer side of the step portion 31 are arranged flush with each other. In addition, description of the step part 31 to FIG. 2 is abbreviate | omitted for convenience.

  As shown in FIG. 2, the heat sink part 4 has a substantially rectangular base part 40 and a heat radiation fin part 41 erected in the height direction Z from the base part 40. The surface opposite to the surface on which the heat radiating fins 41 are formed constitutes a heating element mounting surface 400 on which the heating element is mounted.

  As shown in FIG. 2, the heat radiating fin portion 41 is configured by standing a large number of cylindrical pins 410. Further, the radiating fin portion 41 is arranged such that the region where the pin 410 is erected is smaller than the opening region of the opening 30 so that it can be inserted into the opening 30 of the cooling tube portion 3 as described above. Is formed. Further, the height of the pin 410 in the radiating fin portion 41 is formed to be slightly smaller than the inner dimension in the height direction Z of the cooling pipe portion 3. Accordingly, as shown in FIG. 4, the tip of the pin 410 is configured to be disposed in the vicinity of the inner wall of the cooling pipe portion 3 in a state where the radiating fin portion 41 is inserted and arranged. As the clearance between the tip of the pin 410 and the inner wall of the cooling pipe portion 3 is smaller, the heat dissipation can be improved. Therefore, the clearance between the tip of the pin 410 and the inner wall of the cooling pipe portion 3 is preferably 0.5 mm or less.

  Further, the base portion 40 at the periphery of the heat radiating fin portion 41 is formed flat. Thereby, in the state where the radiating fin portion 41 is inserted and arranged, as shown in FIG. 4, the step portion 31 formed on the inner peripheral edge of the opening 30 and the base portion 40 are configured to be fitted. Further, the inner peripheral edge of the opening 30 and the base portion 40 are joined by friction stir welding, and as shown in FIG. 4, a stirring region 502 is formed along the boundary between the base portion 40 and the wall surface of the cooling pipe portion 3. ing.

  Next, the manufacturing method of the heat exchanger 1 is demonstrated. The manufacture of the heat exchanger 1 includes a housing part forming process for forming the housing part 2 and a heat sink part forming process for forming the heat sink part 4. And the heat exchanger 1 is obtained by performing the assembly process which joins the housing part 2 and the heat sink part 4 which were obtained by these each process using a well-known joining method.

  In the housing part forming step, the housing part 2 including the bottom plate part 20, the cooling pipe part 3 provided with the opening part 30, and the joint part 5 is integrally formed by press-fitting a molten aluminum material into the mold. Form. In this example, the housing 12 shown in FIG. 2 was obtained by die casting using a melt of ADC12 material. In addition, the hollow part in the joint part 5 was formed by using a well-known collapsible core.

  In the heat sink portion forming step, the heat sink portion 4 is formed by various methods such as casting and forging. In this example, the heat sink part 4 shown in FIG. 2 was obtained by hot forging an aluminum alloy material having specific chemical components and specific mechanical characteristics described later.

  Hereinafter, the heat sink part forming step will be described in detail. In this example, the chemical composition is Si: 0.2% (mass%, the same applies hereinafter) to 1.0%, Mg: 0.4% to 1.0%, Fe: 0.35% or less. A forging block was prepared, which was made of an aluminum alloy material containing a balance of unavoidable impurities and 98% or more of aluminum and having a proof stress of 120 MPa or more. Next, the forging block was heated to 500 ° C., the forging die was heated to 150 ° C., and hot forged by a friction press.

  The temperature of the heat sink part 4 immediately after the hot forging was 330 ° C. when taken out from the mold. The heat sink 4 was placed in the atmosphere and allowed to cool (outside of the furnace) to cool to room temperature. In this example, the cooling was performed under the condition that the cooling rate during the cooling period from 300 ° C. to 50 ° C. was 0.45 ° C./sec.

After cooling the heat sink part 4 to room temperature, a heat treatment (artificial aging treatment) was performed at 200 ° C. for 4 hours.
Thereafter, deburring was performed, and shot blasting was performed to remove scale.
Then, the surface (heating element mounting surface 400) opposite to the surface on which the heat dissipating fin portion 41 is disposed in the base portion 40 is cut, and further, the peripheral edge of the heat dissipating fin portion 41 is lightly chamfered to obtain FIG. The heat sink part 4 shown was obtained.

  In the assembly process, the housing part 2 and the heat sink part 4 obtained as described above are joined by a known joining method to obtain the heat exchanger 1 shown in FIG. In this example, the base part 40 in the heat sink part 4 and the inner peripheral edge of the opening part 30 in the housing part 2 were joined by friction stir welding. Specifically, as shown in FIG. 4, the heat sink portion 4 is inserted into the opening 30 with the radiating fin portion 41 facing the bottom plate portion 20, and the peripheral portion of the base portion 40 is the step on the inner peripheral edge of the opening 30. It was made to contact part 31. Thereafter, the rotary tool was press-fitted into one point on the boundary line between the base portion 40 and the wall surface of the cooling pipe portion 3, and the rotary tool was made to make a round along this boundary line. As a result, the stirring region 502 shown in FIG. 4 was formed along the boundary line described above, and the heat sink part 4 and the housing part 2 were joined together to obtain the heat exchanger 1 shown in FIG.

  In the heat exchanger 1 configured as described above, the refrigerant inlet pipe and the refrigerant outlet pipe as external pipes are connected to the communication ports 52 in the pair of joint portions 5, and the heating element is cooled as follows. . First, when the refrigerant liquid is supplied from the refrigerant introduction pipe, the refrigerant liquid is distributed by the joint portion 5, and the refrigerant liquid flows into the respective cooling pipe portions 3. In the cooling pipe portion 3, the refrigerant liquid circulates toward the joint portion 5 on the opposite side, and at the same time, exchanges heat with the radiating fin portion 41 that is in contact with the refrigerant liquid, Remove. The refrigerant liquid that has reached the joint portion 5 on the opposite side passes through the communication port 52 and is discharged to the refrigerant outlet pipe.

  Further, as described above, the heating element cooled by the heat exchanger 1 generates heat from various elements such as power semiconductor elements such as IGBTs, electronic parts such as reactors and capacitors, or power modules combining these elements. It can be mounted on the heating element mounting surface 400 as a body.

  Next, the function and effect of this example will be described. The heat exchanger 1 includes a plurality of cooling pipe portions 3 and a joint portion 5 that collects a plurality of flow paths at both ends of the plurality of cooling pipe portions 3 to form one communication port 52. . This eliminates the need to meander the flow path and facilitates shortening the flow path length, so that the heat exchanger 1 can easily reduce pressure loss, and between the upstream side and the downstream side of the flow path. The difference in heat dissipation is small. As a result, the heat exchanger 1 has excellent heat dissipation performance. Further, the heat exchanger 1 can easily use the plurality of cooling pipe portions 3 only by connecting the pair of communication ports 52 at both ends to the path of the cooling medium.

  Further, the bottom plate portion 20 has a flat plate shape and has an outer peripheral collar portion 24 extending outward from the outer peripheral portion of the cooling pipe portion 3. Thereby, when assembling the heat exchanger 1 to various machines, apparatuses, etc., the shape of the arrangement space can be simplified, and the heat exchanger 1 can be fixed using the outer peripheral collar portion 24. Thereby, the assembly | attachment property of the heat exchanger 1 can be improved.

  Moreover, the housing part 2 which consists of the cooling pipe part 3, the baseplate part 20, and the joint part 5 is integrally formed by die-casting. Therefore, it is not necessary to provide a step of separately preparing and joining the outer peripheral flange portion, the joint portion, and the like, and the housing portion 2 is excellent in productivity.

  Further, the inner peripheral edge of the opening 30 of the cooling pipe portion 3 and the base portion 40 of the heat sink portion 4 are joined by friction stir welding. Therefore, it becomes easy to join the base part 40 and the inner peripheral edge of the opening part 30 so that there is no unjoined part. As a result, it is possible to prevent leakage of the cooling medium from the joint portion between the base portion 40 and the cooling pipe portion 3. Further, since it is not necessary to use a joining member such as a brazing material for joining the base portion 40 and the inner peripheral edge of the opening 30, the member cost can be easily reduced.

  In addition, two cooling pipe portions 3 are provided substantially in parallel, and are connected to joint portions 5 that gather two flow paths into one communication port 52 at both ends thereof. The two cooling pipe portions 3 are disposed at a central position 201 at equal intervals. Therefore, the cooling medium flowing in the flow path is easily distributed evenly to each flow path by the joint portion 5. As a result, it becomes easy to equalize the heat dissipation performance in each flow path, and the cooling design becomes easy.

  In this example, a recess 21 is formed between the two cooling pipe portions 3. Therefore, even if a part of the devices arranged in the peripheral part of the heat exchanger 1 protrudes toward the heat exchanger 1, the protruding portion of the devices can be accommodated in the recess 21 and the dead space is reduced. can do.

  As mentioned above, according to the said aspect, the heat exchanger which has a housing part excellent in heat dissipation performance and productivity can be provided.

  In addition, in the said Example, although the example which formed the cylindrical pin 410 in the radiation fin part 41 in the heat sink part 4 was shown, it is not limited to this, Various shapes are employ | adopted according to cooling design. Is possible. For example, prismatic pins or corrugated fins may be used, or plate fins having a comb-like cross section produced by extrusion processing may be used. Regarding the arrangement and density of the fins, various modes can be adopted in accordance with the cooling design as well as the shape.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Housing part 20 Bottom plate part 24 Outer periphery collar part 3 Cooling pipe part 30 Opening part 4 Heat sink part 40 Base part 400 Heating body mounting surface 41 Radiation fin part 5 Joint part 52 Connection port

Claims (3)

A plate-like bottom plate portion, a plurality of cooling pipe portions forming a plurality of flow passages disposed on one surface of the bottom plate portion, and a plurality of the flow passages are assembled at both ends of the plurality of cooling pipe portions, respectively. And a heat exchanger having a joint portion forming one connection port,
The cooling pipe portion has a heat sink portion disposed in an opening provided on the opposite side of the bottom plate portion,
The heat sink portion includes a plate-like base portion having a heating element mounting surface for mounting the heating element, and a radiation fin portion standing on the surface of the base portion opposite to the heating element mounting surface. And the base part and the inner peripheral edge of the opening of the cooling pipe part are joined in a state where the radiating fin part is inserted into the cooling pipe part,
The bottom plate portion has an outer peripheral collar portion extending outward from an outer peripheral portion of the cooling pipe portion,
The heat exchanger according to claim 1, wherein the housing part including the bottom plate part, the cooling pipe part and the joint part is integrally formed by die casting.   2. The heat exchanger according to claim 1, wherein the inner peripheral edge of the opening of the cooling pipe portion and the base portion of the heat sink portion are joined by friction stir welding.   3. The heat exchanger according to claim 1, wherein two of the cooling pipe portions are provided substantially in parallel, and the joint portion that collects two flow paths at one connecting port at both ends thereof, respectively. The heat exchanger is characterized in that the joint portion is disposed at a central position that is equidistant from the two cooling pipe portions.

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