JP4503202B2 - Heat sink manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat sink for cooling a heat generating device such as a switching circuit.
[0002]
[Prior art]
The switching circuit for driving a motor mounted on a fuel cell vehicle tends to increase the amount of heat generated with the increase in the output of the vehicle driving motor, and how to efficiently dissipate heat and cool it becomes a major issue. ing. The switching circuit includes a semiconductor current conversion circuit such as an inverter and a converter, a current smoothing reactor, and the like.
[0003]
Therefore, in order to cool the heat generating device such as the switching circuit, a heat sink is attached to the heat generating device for cooling. The heat sink is provided with a meandering refrigerant flow path, and a fluid element (for example, a blade fin) that disturbs the flow of the refrigerant in order to increase the cooling effect. Some are composed.
[0004]
As a material for the heat sink, copper or aluminum, which is a material excellent in heat conduction, is widely used. When comparing copper and aluminum, the thermal conductivity of copper is about twice that of aluminum, but the specific gravity of copper is about three times that of aluminum. Therefore, considering the current cost of copper and aluminum, To do the job, copper is about twice as expensive as aluminum. In other words, copper is superior to aluminum in terms of cooling power per volume, but aluminum can be said to be superior to copper in terms of cooling power per price. Taking these into account, aluminum is currently the optimum heat sink material.
[0005]
Conventional aluminum heat sinks mainly have a base plate that forms part of the bottom plate of the heat sink and the refrigerant flow path, and a top plate that mainly forms part of the top plate of the heat sink and a refrigerant flow path as separate parts. Aside from these, a number of aluminum-made blade fins prepared in advance are placed in the coolant flow path of the top plate and brazed, and then the top plate is overlaid on the base plate. In addition, these were manufactured by integrating them by brazing.
[0006]
Thus, when brazing is required in the manufacturing process, there are limits to the aluminum materials that can be brazed. For example, 1000 series (A1100, A1200, etc.) pure aluminum material, or manganese is added to pure aluminum. It is limited to 3000 series (A3003, etc.) aluminum materials with increased strength and 6000 series (A6061, A6063, etc.) aluminum materials used as structural materials.
On the other hand, the refrigerant flow path of the heat sink is complicated, and cutting, casting, and forging are suitable for its processing. However, if it is limited to brazing aluminum materials, only the cutting method can be adopted due to the properties of those materials. .
[0007]
Therefore, conventionally, a top plate and a base plate (hereinafter, these are collectively referred to as a main body) are manufactured by cutting from an aluminum material that can be brazed, and a blade fin is brazed to the coolant flow path of the top plate. Furthermore, the top plate is overlaid on the base plate, and these are integrated by brazing.
[0008]
[Problems to be solved by the invention]
However, when the heat sink main body is manufactured by cutting an aluminum material, there is a problem that it takes a long time to manufacture, the productivity is poor, and the manufacturing cost is high, which is disadvantageous.
Accordingly, the present invention provides a method of manufacturing a heat sink that can improve productivity and reduce costs without degrading the heat dissipation performance of the heat sink.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, the invention described in claim 1 is used for cooling an electronic device and corresponds to a first plate having unevenness (for example, a top plate 30 in an embodiment described later) and the unevenness. A refrigerant flow path (for example, a refrigerant flow path 10 in an embodiment described later) meanderingly provided by superimposing and integrating with a concave and convex second plate (for example, a base plate 20 in the embodiment described later). In a method of manufacturing a heat sink (for example, a heat sink 5 in an embodiment to be described later), along the coolant flow direction (for example, the left and right direction of the heat sink in the embodiment to be described later) in one direction portion of the coolant channel. by cutting after extrusion to form said first plate, said one-way portion of the coolant channel The refrigerant flow direction (e.g., longitudinal direction of the heat sink in the embodiment described below) in the other direction part of the difference to the cutting after extrusion along the forming the second plate, along the flow direction of the refrigerant After brazing a fluid element having a large number of arranged fins (for example, a blade fin 40 in an embodiment described later) onto at least one of the first plate and the second plate, One plate and the second plate are overlapped and integrated.
With this configuration, in both the first plate and the second plate, the part that can be extruded can be formed by extrusion molding first, and only the part that is difficult to process by extrusion molding can be formed by cutting. It becomes possible.
Here, "crossing" also emerged from equilibrium than complete orthogonality condition, Ru der which one and the other is also a condition for forming a nip angle less than 45 ° or more 90 °.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a heat sink manufacturing method according to the present invention will be described below with reference to the drawings of FIGS. In addition, the heat sink in this embodiment is the aspect applied to the fuel cell vehicle.
FIG. 1 is a schematic configuration diagram of a fuel cell vehicle V of this embodiment. In this figure, reference numeral 1 denotes a main motor (MOT) for traveling, and the main motor 1 for traveling is a power control unit (PCU). 2 are connected to a fuel cell stack (FCSTK) 3 and a power storage (battery, capacitor, etc.) 4 for power regeneration and the like. In FIG. 1, the battery is indicated as “BATT”.
[0011]
The power control unit 2 includes a power drive unit for a supercharger, a high voltage conversion circuit, and a power drive unit for a main motor (all not shown), and electronic devices that are heat generating devices are mounted on each part.
The supercharger power drive unit is a power supply unit for a supercharger (not shown) that supplies air as an oxidant gas to the fuel cell stack 3. The high voltage conversion circuit converts the output voltage of the fuel cell stack 3 into a predetermined voltage, and distributes power among the fuel cell stack 3, the capacitor 4, and each power drive unit, and is one of electronic devices. A current smoothing reactor is also arranged. The main motor power drive unit is provided with electronic devices such as an inverter, a semiconductor current conversion circuit such as a converter, and a capacitor, which are switching circuits for driving the main motor 1.
[0012]
A heat sink 5 for taking heat away from the electronic device as a heat generating device equipped in the power control unit 2 is disposed below the power control unit 2. The heat sink 5 has a refrigerant flow path 10 inside, and the refrigerant flow path 10, the water pump (W / P) 6 and the radiator 7 are connected by a cooling pipe 8 to form a closed circuit. The coolant is circulated. That is, the coolant is pumped to the heat sink 5 by the water pump 6 and takes heat from the electronic device of the power control unit 2 when flowing through the refrigerant flow path 10 of the heat sink 5, and the heated coolant is cooled by the radiator 7. Return to the water pump 6 again.
[0013]
Before describing the manufacturing method of the heat sink 5, the structure of the heat sink 5 as a finished product will be described first. FIG. 2 is a bottom view of the heat sink 5 with a part broken away, and FIG. 3 is an exploded perspective view of the heat sink 5.
As shown in FIGS. 2 and 3, the heat sink 5 includes a base plate (second plate) 20 that mainly forms a part of the bottom plate 21 and the refrigerant flow path 10, and mainly a top plate 31 and the refrigerant flow path 10. A top plate (first plate) 30 that forms a part, and a blade fin 40 as a fluid element for disturbing the flow of the coolant flowing through the refrigerant flow path 10 of the top plate 30 are configured.
[0014]
The heat sink 5 as a finished product is configured by superimposing a base plate 20 and a top plate 30. When the heat sink 5 is superposed, the periphery thereof is surrounded by a side wall, and a meandering refrigerant flow path 10 is formed therein. It has a structure.
The base plate 20 is formed with irregularities. That is, the base plate 20 includes a bottom plate 21, a left side wall 22 and a right side wall 23 formed on both sides of the bottom plate 21, and a space 24 having an upper opening is formed between the left and right side walls 22 and 23. Further, in the portions facing the space 24 in the left and right side walls 22 and 23, turning recesses 25a, 25b and 25c for turning the coolant flow by about 180 ° and a coolant inflow recess 26 are formed. Guide plates 27 a, 27 b, 27 c that guide the coolant along the swivel recess 25 are provided upright from the bottom plate 21 in the vicinity of the swivel recesses 25 a, 25 b, 25 c. The left side wall 22 is provided with a coolant inlet hole 28 that penetrates the coolant inflow recess 26.
[0015]
Similar to the base plate 20, the top plate 30 is formed with irregularities. That is, the top plate 30 has a predetermined distance between the top plate 31, the front side walls 32 and the rear side walls 33 formed on the front and rear portions of the top plate 31, and the front and rear side walls 32 and 33 projecting from the lower surface of the top plate 31. The three flow path walls 34a, 34b, and 34c that are linearly extended in the left-right direction are provided. The space below the top plate 31 and where the front and rear side walls 32, 33 and the three flow path walls 34 a to 34 c do not exist is the refrigerant flow path 10. A coolant outlet hole 36 is formed through the left end portion of the rear side wall 33. Further, it is the lower surface of the top plate 31, between the front side wall 32 and the flow path wall 34 a, between the flow path wall 34 a and the flow path wall 34 b, and between the flow path wall 34 c and the rear side wall 33. Projection pieces 35a, 35b, and 35c for positioning blade fins are provided at predetermined positions, respectively.
[0016]
When the top plate 30 is superimposed on the base plate 20 so that the front and rear side walls 32 and 33 and the flow path walls 34a to 34c of the top plate 30 are inserted into the space 24 of the base plate 20, the top plate of the top plate 30 is obtained. The upper opening of the space 24 of the base plate 20 is completely closed by 31, and the lower surfaces of the flow path walls 34 a, 34 b, 34 c of the top plate 30 are in contact with the upper surface of the bottom plate 21 of the base plate 20. At the same time, the left and right end portions of the front and rear side walls 32 and 33 of the top plate 30 abut on the side surfaces of the left and right side walls 22 and 23 of the base plate 20, and the left end portion of the flow path wall 34 a is the side surface of the left side wall 22 of the base plate 20. The right end portion of the flow path wall 34a is located inwardly of the guide plate 27b of the base plate 20, the right end portion of the flow path wall 34b is in contact with the side surface of the right side wall 23 of the base plate 20, and the flow path The left end portion of the wall 34b is located inwardly of the guide plate 27a of the base plate 20, the left end portion of the flow channel wall 34c contacts the side surface of the left side wall 22 of the base plate 20, and the right end portion of the flow channel wall 34c is The base plate 20 is positioned so as to be spaced away from the guide plate 27c on the inner side, so that the coolant inlet hole 28 and the coolant are located between the bottom plate 21 and the top plate 31. Refrigerant flow path 10 for connecting the outlet aperture 36 is adapted to be formed in a meandering. That is, the coolant channel 10 is formed by the unevenness of the top plate 30 and the unevenness of the base plate 20 corresponding to the unevenness.
[0017]
The blade fin 40 is disposed at a predetermined position on the refrigerant flow path 10 in the top plate 30 and fixed by brazing before the base plate 20 and the top plate 30 are overlapped. Here, adjacent blade fins 40 are arranged offset in the fin thickness direction so that the fins of both blade fins 40 do not line up in a straight line. Further, the base plate 20 and the top plate 30 are joined together by brazing after overlapping them.
In addition, screw holes 9 for attaching electronic devices such as a switching circuit are provided on the upper surfaces of the left and right side walls 22 and 23 of the base plate 20 and the upper surface of the top plate 31 of the top plate 30.
[0018]
Next, the manufacturing method of this heat sink 5 is demonstrated with reference to drawings of FIGS. FIG. 4 is a diagram schematically showing a method of manufacturing the heat sink 5. Since the base plate 20 and the top plate 30 are shown in a simplified manner, the base plate 20 and the top plate 30 shown in FIGS. The shape is slightly different.
Both the base plate 20 and the top plate 30 are made of brazing aluminum material (for example, 1000 series such as A1100 and A1200, 3000 series such as A3003, and 6000 series aluminum material such as A6061, A6063).
[0019]
First, a method for manufacturing the top plate 30 will be described. First, an aluminum raw material is extruded to produce a top plate substrate 300 having a cross-sectional shape shown in FIG. 5B (see FIG. 4A). That is, the cross-sectional shape of the top plate substrate 300 has thick wall portions 320 and 330 on both the left and right sides of the thin bottom portion 310, and three thick wall portions 340a at predetermined intervals between the thick wall portions 320 and 330. , 340b, 340c, three thin standing wall portions 350a at a predetermined interval between the thick wall portion 320 and the thick wall portion 340a, and between the thick wall portion 340a and the thick wall portion 340b Two thin standing wall portions 350b are provided at a predetermined interval therebetween, and two thin standing wall portions 350c are provided at a predetermined interval between the thick wall portion 340c and the thick wall portion 330.
[0020]
Here, the thin-walled bottom portion 310 is a portion corresponding to the top plate 31 in the top plate 30, the thick-walled portion 320 is a portion corresponding to the front side wall 32 of the topplate 30, and the thick-walled portion 330 is The thick wall portions 340a, 340b, and 340c are portions corresponding to the flow path walls 34a, 34b, and 34c of the top plate 30 and the thin standing wall portions 350a and 350b, respectively. , 350c are portions corresponding to the protruding pieces 35a, 35b, 35c of the top plate 30, respectively.
Therefore, in this case, the extrusion direction when extruding the top plate substrate 300 is a refrigerant flow path portion (one direction portion of the refrigerant flow path) extending straight in the left-right direction of the refrigerant flow path 10 of the heat sink 5. Is set in a direction along the coolant flow direction (refrigerant flow direction), in other words, in a direction along the left-right direction of the top plate 30.
[0021]
Then, by cutting the top plate substrate 300 manufactured by extrusion, the shape of the top plate 31 of the top plate 30 is cut out (see FIG. 4B), and the thick wall portions 320 and 330 are cut out. The front and rear side walls 32, 33 are cut out from the wall, the flow path walls 34a, 34b, 34c are cut out from the thick wall portions 340a, 340b, 340c (see FIG. 4C), and protrude from the thin upright wall portions 350a, 350b, 350c. The pieces 35a, 35b, and 35c are cut out. FIG. 5A is a plan view after this cutting. Thereafter, the coolant outlet hole 36, the screw hole 9 and the like are formed in a necessary portion by using an appropriate processing means such as a drill to complete the top plate 30.
[0022]
Next, a method for manufacturing the base plate 20 will be described. First, an aluminum raw material is extruded to produce a base plate substrate 200 having a cross-sectional shape shown in FIG. 6B having thick wall portions 220 and 230 on both the left and right sides of the thin bottom portion 210 (see FIG. 4D). ). Here, the thin-walled bottom portion 210 is a portion corresponding to the bottom surface 21 of the base plate 20, and the thick-walled portion 220 is a portion corresponding to the left side wall 22, the coolant inflow recess 26, the turning recess 25a, and the guide plate 27a. is there. The separation dimension W of the thick wall portions 220 and 230 is made to coincide with the minimum width in the left-right direction in the space 24 of the base plate 20.
In this case, the extruding direction when extruding the base plate substrate 200 is a refrigerant flow path portion for rotating the coolant in the refrigerant flow path 10 of the heat sink 5 by about 180 ° (substantially orthogonal to one direction portion of the refrigerant flow path. The coolant flow direction (refrigerant flow direction) in the other direction portion, that is, the direction along the front-rear direction of the base plate 20 is set.
[0023]
Then, by cutting the base plate substrate 200 manufactured by extrusion, the shape of the bottom plate 21 of the base plate 20 is cut out, and the left and right side walls 22 and 23 and the turning recess 25a are cut out from the thick wall portions 220 and 230. 25b, 25c, coolant inflow recess 26, and guide plates 27a, 27b, 27c are cut out (see FIG. 4E). FIG. 6A is a plan view after this cutting. Thereafter, the coolant inlet hole 28, the screw hole 9 and the like are formed at a necessary location using an appropriate processing means such as a drill, and the base plate 20 is completed.
[0024]
Next, the blade fins 40 are arranged at predetermined positions on the top plate 30 and fixed by brazing. In FIG. 4, the description of this step is omitted.
Then, the top plate 30 with the blade fins 40 mounted thereon is overlaid on the base plate 20 (see FIG. 4F), and both are fixed by brazing, whereby the heat sink 5 shown in FIG. 2 is manufactured.
[0025]
In this method of manufacturing the heat sink 5, both the base plate 20 and the top plate 30 are formed in a short time in a simple process by extruding at first, and only parts that are difficult to process by extruding are formed. It is formed by cutting that is complicated and takes a little time.
Therefore, the productivity can be improved and the cost can be reduced as compared with the conventional case where the heat sink is manufactured by forming the base plate and the top plate only by cutting.
[0026]
[Other Embodiments]
The present invention is not limited to the embodiment described above. For example, in the above-described embodiment, the blade fin 40 is fixed to the top plate 30, but may be fixed to the base plate 20 by brazing.
In addition, although the drawing direction of the base plate 20 intersects with the pushing direction of the top plate 30 at an angle of 90 ° is shown in each drawing, the present invention is not limited thereto, and the pushing direction intersects with the pushing direction of the top plate 30 at an angle of 45 °, for example. Even if the direction is selected and set, the flow path can be formed, and the same effect as in the above embodiment is obtained.
[0027]
【The invention's effect】
As described above, according to the first aspect of the present invention, in both the first plate and the second plate, the portion that can be extruded is formed by extrusion molding first, and the portion that is difficult to process by extrusion molding. As a result, the productivity is improved and the cost is reduced compared to the conventional method of manufacturing the heat sink by forming the first and second plates only by cutting. it Ru is exhibited an excellent effect that it is.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a fuel electric vehicle including a heat sink according to the present invention.
FIG. 2 is a bottom view of a heat sink.
FIG. 3 is an exploded perspective view of a heat sink.
FIG. 4 is a view showing a manufacturing procedure of a heat sink.
5A is a view of a top plate constituting a heat sink as viewed from the back side, and FIG. 5B is a front view at the time of top plate extrusion molding.
6A is a plan view of a base plate constituting a heat sink, and FIG. 6B is a front view at the time of base plate extrusion molding.
[Explanation of symbols]
5 Heat sink 10 Refrigerant flow path 20 Base plate (second plate)
22, 23 side wall
25a-25c turning recess 30 top plate (first plate)
34a-34c Channel wall 40 Blade fin (fluid element)

Claims (1)

In a method of manufacturing a heat sink having a meandering refrigerant flow path by superimposing a first plate having irregularities and a second plate having irregularities corresponding to the irregularities, which is used for cooling electronic equipment , ,
The first plate is formed by cutting after extrusion molding along the refrigerant flow direction in one direction portion of the refrigerant flow path,
The second plate is formed by cutting after extrusion molding along the refrigerant flow direction in the other direction portion intersecting the one direction portion of the refrigerant flow path,
After brazing a fluid element having a large number of fins arranged along the flow direction of the refrigerant onto the refrigerant flow path in at least one of the first plate and the second plate,
Producing how the heat sink, characterized in that the integrally superposed and the said first plate a second plate.

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