JP2022090834A - Wave-type heat transfer fin - Google Patents

Abstract

To provide a wave-type heat transfer fin which is further simpler in manufacturing.SOLUTION: In a wave-type heat transfer fin which has a prescribed dimension in a first direction, and in which an undulation having a prescribed cycle is formed in a second direction orthogonal to the first direction by a wave-shaped circulation face, and fluid circulates on the circulation face, a step part is formed at the circulation face, and arranged over one end toward the other end of the circulation face in the first direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wave-type heat transfer fin.

The following Patent Document 1 discloses a heat transfer tube for a heat exchanger. As is clearly shown in FIG. 1 and the like, this heat transfer tube for heat exchanger has a corrugated fin structure built in the inner peripheral surface of the flat tube. This corrugated fin structure is a channel-shaped waveform having a substantially rectangular cross-sectional shape, has a curved curved surface in which undulations of the waveform are formed at a predetermined wavelength in the longitudinal direction, and the wave width of the channel shape is H in the longitudinal direction. When the wavelength of the swell is L and the amplitude of the swell in the longitudinal direction is A, the H / L is 0.17 to 0.20, and the ratio of the gap G to H obtained by HA (G / H). ) Is set to −0.21 to 0.19.

Further, Patent Document 2 below discloses a heat exchanger and a corrugated fin. As is clearly shown in FIG. 3 and the like, the corrugated fin in Patent Document 2 is formed by being bent so as to form a wave shape between a plurality of tubes arranged in one direction, and is a first fluid flowing through the tubes. It promotes heat exchange between the fluid and the second fluid flowing between the tubes.

More specifically, the corrugated fin of Patent Document 2 has a plurality of joints joined to a tube and a plurality of fins connected to each of the joints so as to connect between adjacent joints along a wave shape. It has a main body. The fin main body has a cut-up portion having a partially cut-up shape, and the cut-up portion extends from the cut-up main body portion for guiding the second fluid and the cut-up main body portion. It has a plate-like shape and has a cut-up end provided at at least one end in one direction of the cut-up portion, and is formed so as to enhance the hydrophilicity of the surface of the cut-up end. The shape is cut up and held in at least one of the plate thickness directions at the end.

Japanese Unexamined Patent Publication No. 2007-0798194 Japanese Unexamined Patent Publication No. 2019-21115

By the way, the corrugated fin structure (wave type heat transfer fin) of Patent Document 1 can be said to be a corrugated fin, and by optimizing the relationship between the wave width H, the swell wavelength L, and the swell amplitude A, the exhaust gas flow path. The high-temperature exhaust gas flowing through the gas has a uniform flow velocity distribution and promotes heat exchange with the cooling medium flowing outside the heat transfer tube. Further, the corrugated fin of Patent Document 2 is intended to promote heat transfer between the first fluid and the second fluid by providing a cut-up portion in the fin main body portion.

Here, by providing the cut-out portion of Patent Document 2 in the corrugated fin structure of Patent Document 1, it is possible to promote heat transfer between the exhaust gas and the cooling medium in the corrugated fin structure of Patent Document 1. Although it is possible, when the cut-up portion is formed in the corrugated fin structure, there is a problem that the manufacturing process of the corrugated fin structure becomes complicated, and as a result, the manufacturing cost becomes high.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wave-type heat transfer fin that is easier to manufacture.

In order to achieve the above object, in the present invention, as a first solution for the wave type heat transfer fin, a second means having a predetermined dimension in the first direction and orthogonal to the first direction by the distribution surface of the waveform. A wave-type heat transfer fin in which undulations of a predetermined period are formed along a direction and a fluid flows through the flow surface, and a step portion is provided on the flow surface, and the step portion is the step portion in the first direction. A means of being provided from one end to the other end of the distribution surface is adopted.

In the present invention, as a second solution for the wave-type heat transfer fin, in the first solution, a means for providing the refrigerant flow path in the heat sink in which the refrigerant flow path is formed is provided. adopt.

In the present invention, as a third solution for the wave-type heat transfer fin, in the second solution, the swell is formed in a shape in which straight portions having different directions are alternately connected, and the step portion is formed. A means of being provided in a plurality of straight portions in the second direction is adopted.

According to the present invention, it is possible to provide a wave-shaped heat transfer fin that is easier to manufacture.

It is a perspective view which shows the disassembled structure of the heat sink A in one Embodiment of this invention. It is a front view (a) and a side view (b) which show the structure which shows the shape of the corrugated fin 3A, 3B (wave type heat transfer fin) which concerns on one Embodiment of this invention. It is an enlarged front view (a) and the enlarged side view (b) which show the shape of the corrugated fin 3A, 3B (wave type heat transfer fin) which concerns on one Embodiment of this invention. It is a perspective view which shows the shape of the wave type heat transfer fins 3A, 3B which concerns on the modification of one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the structure of the heat sink A in the present embodiment will be described with reference to FIG. In addition, in this FIG. 1, in order to clarify the direction, three axes (X-axis, Y-axis and Z-axis) that are orthogonal to each other are added. Of the directions along these three axes, the direction parallel to the Z axis corresponds to the first direction of the present invention, and the direction parallel to the Y axis corresponds to the second direction of the present invention.

The heat sink A is a component of a PCU (Power Control Unit) that is mounted on an electric vehicle and includes a plurality of semiconductor switching transistors. Further, the heat sink A is a mechanical component that dissipates heat from a plurality of semiconductor switching transistors that generate heat in relation to switching electric power.

As is well known, the PCU is a power converter (such as a buck-boost converter or an inverter) that drives a traveling motor provided in an electric vehicle, and has a plurality of DC powers supplied from a high-voltage power source such as a lithium-ion battery. It is converted into AC power using the semiconductor switching transistor of the above and output to the traveling motor.

The heat sink A in the present embodiment is for dissipating heat generated by a plurality of semiconductor switching transistors (semiconductor chips) in such a PCU to the outside, and as shown in FIG. 1, the upper cover 1 and the lower cover 2 are used. It includes two corrugated fins 3A and 3B (wave-shaped heat transfer fins), a stay 4, a first connecting member 5A and a second connecting member 5B.

Of the upper cover 1, the lower cover 2, the two corrugated fins 3A, 3B, and the stay 4, the upper cover 1 and the lower cover 2 are mechanical parts constituting the housing of the heat sink A. This housing includes a substantially rectangular fluid flow passage R as described later.

That is, the upper cover 1 is a substantially rectangular flat plate-shaped member, and the upper surface is a flat plate bonding surface 1a to which the semiconductor chips are thermally coupled. Further, the upper cover 1 is a flat cover joint surface 1b to which the lower cover 2 is bonded to the lower surface, that is, the back surface of the chip joint surface 1a.

Further, the upper cover 1 is provided with a total of eight screw holes 1c to 1j as shown in the figure. Of these eight screw holes 1c to 1j, the four screw holes 1c to 1f are discretely arranged near the outer peripheral portion of the upper cover 1. These four screw holes 1c to 1f are for fixing the heat sink A to the PCU main body, and fixing screws (not shown) are inserted into each of them.

Of the remaining four screw holes 1g to 1j, the two screw holes 1g and 1h are arranged as a pair in the vicinity of one of the short sides of the pair of short sides of the upper cover 1. These two screw holes 1g and 1h are for fixing the first connecting member 5A, and fixing screws (not shown) are inserted into each of them.

Further, the remaining two screw holes 1i and 1j are arranged as a pair in the vicinity of the other short side of the upper cover 1. These two screw holes 1i and 1j are for fixing the second connecting member 5B, and fixing screws (not shown) are inserted into each of them.

The lower cover 2 is a substantially rectangular flat plate-shaped member whose peripheral edge portion rises by a predetermined dimension in the Z-axis direction, and the peripheral edge portion, that is, the tip of the rising portion is in contact with the cover joint surface 1b of the upper cover 1. Be joined. The housing of the heat sink A composed of the upper cover 1 and the lower cover 2 is a hollow housing in which a substantially rectangular cavity (refrigerant flow path R) is formed inside.

That is, the upper surface of the lower cover 2 is the flow path forming surface 2a constituting the bottom surface of the refrigerant flow path R, and the lower surface is the fixed surface 2b. Of the cover joint surface 1b of the upper cover 1 described above, the region surrounded by the rising portion of the lower cover 2 is the refrigerant flow path R in a state of facing the flow path forming surface 2a of the lower cover 2 in the first direction. It is a flow path forming surface that constitutes the top surface.

In the refrigerant flow path R formed by the upper cover 1 and the lower cover 2, the short side direction is parallel to the X axis, the long side direction is parallel to the X axis, and the height direction is the Z axis. The directions are parallel. Further, such a fluid flow passage R has a volume determined by a short side dimension, a long side dimension, and a height dimension.

Further, the lower cover 2 is provided with a fluid inlet 2c and a fluid outlet 2d. These fluid inlets 2c are provided in the vicinity of one short side of the substantially rectangular lower cover 2, and are openings through which the liquid refrigerant flows toward the refrigerant flow path R. The fluid outlet 2d is provided in the vicinity of the other short side of the substantially rectangular lower cover 2, and is an opening through which the liquid refrigerant flows out from the refrigerant flow path R.

That is, in the heat sink A in the present embodiment, the liquid refrigerant enters the refrigerant flow path R from the fluid inflow port 2c, and the refrigerant flow path R is connected to the fluid outlet 2d provided at the position farthest from the fluid inflow port 2c. It circulates toward the outside and flows out from the fluid inlet 2c. Such a liquid refrigerant is heated by the heat of a plurality of semiconductor chips while flowing through the refrigerant flow path R.

The two corrugated fins 3A and 3B are rectangular members having a predetermined height as shown in the figure, and both are formed in the same shape. These corrugated fins 3A and 3B are housed in the refrigerant flow path R so as to be adjacent to each other. That is, the upper surfaces of the two corrugated fins 3A and 3B in FIG. 1 are fixed to the flow path forming surface of the upper cover 1 by brazing or the like.

Here, in the corrugated fins 3A and 3B, the height direction (Z-axis direction) corresponds to the first direction of the present invention, and the long side direction (Y-axis direction) corresponds to the second direction of the present invention. That is, the two corrugated fins 3A and 3B have their long sides parallel to the long side direction (Y-axis direction) of the fluid flow passage R similarly formed in a rectangular shape, and the refrigerant flow path R. It is housed in the fluid flow passage R in a posture so as to be adjacent to each other in the short side direction (X-axis direction).

Subsequently, the detailed shapes of the corrugated fins 3A and 3B will be described with reference to FIG. These two corrugated fins 3A and 3B are press-molded products formed into a corrugated shape (corrugated plate shape) by pressing a sheet metal (base material), and are a continuum of a plurality of corrugated portions 3a arranged in parallel. .. The plurality of wave portions 3a are portions that protrude from the flow path forming surface 2a of the lower cover 2 toward the upper cover 1 side with a predetermined dimension D and a predetermined interval E. That is, the corrugated fins 3A and 3B have a predetermined dimension D in the Z-axis direction (first direction), which is the height direction.

Further, as shown in the figure, the plurality of wave portions 3a undulate in a predetermined period T along the long side direction (Y-axis direction, second direction) orthogonal to the height direction (Z-axis direction, first direction). There is. That is, the corrugated fins 3A and 3B swell in a predetermined period T along the long side direction (Y-axis direction, second direction) orthogonal to the height direction (Z-axis direction, first direction) by the wave portion 3a of the waveform. Is formed.

As shown in the figure, the swell is formed in a shape in which straight lines 3b having different directions are alternately connected. That is, this swell has a shape in which the wave portion 3a extending in the long side direction (Y-axis direction, second direction) is bent in the short side direction (X-axis direction), in other words, the bending direction is the long side direction (Y). It has a shape in which straight portions 3b that are opposite to the axial direction (second direction) are alternately connected in the long side direction (Y-axis direction, second direction).

Further, the swell is provided so that all the wave portions 3a have the same phase in the long side direction (Y-axis direction, second direction). That is, in the corrugated fins 3A and 3B, the distance between the wave portions 3a adjacent to each other is kept substantially constant at any position in the long side direction (Y-axis direction, second direction).

Further, the arrangement direction of the plurality of wave portions 3a is the short side direction (X-axis direction) of the corrugated fins 3A and 3B, and the extending direction is the long side direction (Y-axis direction) of the corrugated fins 3A and 3B. In such a plurality of wave portions 3a, in a state where the corrugated fins 3A and 3B are housed in the refrigerant flow path R, the top portion 3c is brazed and fixed to the flow path forming surface of the upper cover 1, and the bottom portion 3d is the lower cover. It is in contact with the flow path forming surface 2a of 2.

Further, in such a plurality of wave portions 3a, one end is a refrigerant inflow end 3e facing the fluid inflow port 2c of the lower cover 2, and the other end is a refrigerant outflow end 3f facing the fluid outflow port 2d of the lower cover 2. .. That is, in the plurality of wave portions 3a, one end (refrigerant inflow end 3e) is located near the fluid inlet 2c, and the other end (refrigerant outflow end 3f) is located near the fluid outlet 2d.

In such a heat sink A, the liquid refrigerant flowing into the refrigerant flow path R from the fluid inflow port 2c enters the plurality of wave portions 3a from the refrigerant inflow end 3e, and the surface of the plurality of wave portions 3a, that is, the first flow surface 3g. It flows through the back surface, that is, the second distribution surface 3h, and reaches the fluid outlet 2d via the refrigerant outflow end 3f.

That is, the above-mentioned refrigerant flow path R is the flow path forming surface of the first refrigerant flow path R1, the second flow path 3h, and the lower cover 2 surrounded by the first flow path 3g and the flow path forming surface of the upper cover 1. It is composed of a second refrigerant flow path R2 surrounded by 2a.

Here, FIG. 3 is a side view (a) of two adjacent straight line portions 3b and a view taken along the line CC in the side view (b). As shown in FIG. 3, step portions 3i are formed on both sides of the straight portion 3b. As shown in FIG. 3, the step portion 3i has a corner portion 3j and a corner portion 3k, and has a predetermined step (depth) corresponding to the distance between the corner portion 3j and the corner portion 3k. Focusing on one wave portion 3a, the step portions 3i are formed on both sides in a state of being offset in the long side direction (Y-axis direction, second direction).

Further, focusing on one step portion 3i, the step portion 3i is the entire region in the height direction (Z-axis direction, first direction) of the wave portion 3a, that is, the height direction (Z-axis direction, first direction). It is provided from one end to the other end of the first distribution surface 3g in the above. Further, the corner portion 3j and the corner portion 3k have an angle of approximately 90 °, and the surface (connecting surface 3m) connecting the corner portion 3j and the corner portion 3k is a flat surface.

Focusing on the straight line portion 3b described above, one such step portion 3i is provided on both sides of one straight line portion 3b. Such a plurality of step portions 3i are peeling portions that cause a peeling phenomenon with respect to the liquid refrigerant flowing from the refrigerant inflow end 3e toward the refrigerant outflow end 3f on the first flow surface 3g. By stirring the liquid refrigerant based on the peeling phenomenon, the plurality of stages 3i do not circulate the liquid refrigerant as a laminar flow in the first refrigerant flow path R1, but circulate it as a turbulent flow.

By the way, the stay 4 shown in FIG. 1 is a plate-shaped member for fixing the housing to the PCU main body, and screw holes 4a to 4d are provided at a total of four places. The upper surface of the stay 4 is joined to the fixed surface 2b (lower surface) of the lower cover 2. Further, the stay 4 is fixed to the PCU main body by fixing screws (not shown) that are commonly inserted into the screw holes 4a to 4d of the stay 4 and the four screw holes 1c to 1f in the upper cover 1. That is, the upper cover 1 and the stay 4 are fixed to the PCU main body in a state of being jointly tightened by the fixing screws.

The first connecting member 5A is a substantially disk-shaped member provided with an opening 5a in the central portion and screw holes 5b and 5c respectively provided at two locations on the peripheral portion so as to sandwich the opening 5a. The first connecting member 5A is a connecting tool for connecting an external pipe for supplying the liquid refrigerant to the heat sink A to the fluid inlet 2c of the lower cover 2.

The second connecting member 5B is a substantially disk-shaped member provided with an opening 5d in the central portion and screw holes 5e and 5f respectively provided at two locations on the peripheral portion so as to sandwich the opening 5d. The second connecting member 5B is a connecting tool for connecting an external pipe for discharging the liquid refrigerant from the heat sink A to the fluid outlet 2d of the lower cover 2.

Next, the action and effect of the heat sink A configured as described above, particularly the action and effect of the corrugated fins 3A and 3B (wave type heat transfer fins) according to the present embodiment will be described in detail.

As described above, in the heat sink A in the present embodiment, a plurality of semiconductor chips (heat generating equipment) are thermally coupled to the chip bonding surface 1a of the upper cover 1. That is, the heat generated by the plurality of semiconductor chips is transferred to the upper cover 1 of the heat sink A. Then, the heat of the semiconductor chip is transferred to the two corrugated fins 3A and 3B housed in the refrigerant flow path R of the heat sink A.

Then, the heat of the semiconductor chip transferred to the corrugated fins 3A and 3B is transferred to the liquid refrigerant flowing through the refrigerant flow path R to heat the liquid refrigerant. Since the liquid refrigerant circulates from the fluid inlet 2c of the lower cover 2 toward the fluid outlet 2d, that is, it circulates in the refrigerant flow path R, the semiconductor chips that have transferred heat to the corrugated fins 3A and 3B. The heat is sequentially transferred to the liquid refrigerant and suppresses the temperature rise of the semiconductor chip.

Here, since the corrugated fins 3A and 3B are provided with a plurality of step portions 3i, the heat transfer performance is improved as compared with the case where the plurality of step portions 3i are not provided. That is, the corrugated fins 3A and 3B according to the present embodiment are superior in heat transfer performance as compared with those without a plurality of step portions 3i.

These two corrugated fins 3A and 3B are formed by pressing a sheet metal (base material) so as to have a plurality of step portions 3i, and the formation of the plurality of step portions 3i is extremely easy. be. That is, according to the present embodiment, it is possible to provide corrugated fins 3A and 3B (wave type heat transfer fins) that are easier to manufacture.

Further, according to the present embodiment, since the corrugated fins 3A and 3B (wave type heat transfer fins) can be easily manufactured, the manufacturing cost of the corrugated fins 3A and 3B can be reduced, and thus the manufacturing cost of the heat sink A can be reduced. Can also be reduced.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the above embodiment, one step portion 3i is provided on each side of one straight portion 3b, but the present invention is not limited to this. For example, as shown in FIG. 3, two step portions 3i may be provided on both sides of one straight portion 3b. Further, three or more step portions 3i may be provided on both sides of one straight portion 3b. That is, a plurality of the step portions 3i may be provided in one straight line portion 3b in the long side direction (Y-axis direction, second direction).

(2) In the above embodiment, the step portions 3i are provided on both sides of the straight portion 3b, but the present invention is not limited to this. For example, a step portion 3i may be provided on one side of the straight portion 3b. When the step portion 3i is provided on one side of each straight portion 3b, the step portion 3i is provided so that the step portion 3i exists on any one of the pair of facing surfaces formed by the wave portions 3a adjacent to each other in the X-axis direction. Is preferable.

(3) In the above embodiment, the two corrugated fins 3A and 3B are housed in the refrigerant flow path R, but the present invention is not limited thereto. For example, two corrugated fins 3A and 3B may be integrated, that is, one corrugated fin may be housed in the refrigerant flow path R.

A heat sink R1 1st refrigerant flow path R2 2nd refrigerant flow path 1 upper cover 1a chip joint surface 1b cover joint surface 1c to 1f screw hole 2 lower cover 2a flow path forming surface 2b fixed surface 2c fluid inflow port 2d fluid outflow port 3A 3B corrugated fin (wave type heat transfer fin)
3a Wave part 3b Straight part 3c Top 3d Bottom 3e Refrigerant inflow end 3f Refrigerant outflow end 3g 1st distribution surface 3h 2nd distribution surface 3i Step 3j Corner 3k Square 3m Connection surface 4 Stay 4a-4d Screw hole 5A 1st Connection member 5B Second connection member 5a, 5b Opening 5c-5f Screw hole

Claims (3)

A wave-shaped heat transfer fin having a predetermined dimension in the first direction, having a swell of a predetermined period formed along a second direction orthogonal to the first direction by a corrugated flow surface, and a fluid flowing through the flow surface. There,
A step portion is provided on the distribution surface, and a step portion is provided.
The step portion is a wave-shaped heat transfer fin provided from one end to the other end of the flow surface in the first direction. The wave-shaped heat transfer fin according to claim 1, wherein the refrigerant flow path is provided in the refrigerant flow path in a heat sink having a refrigerant flow path formed therein. The swell is formed in a shape in which straight portions having different directions are alternately connected.
The wave-shaped heat transfer fin according to claim 1 or 2, wherein a plurality of the step portions are provided on the straight portion in the second direction.

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