COOLING APPARATUS
Fins are each formed with a flat shape in a height direction, which is orthogonal to a flow direction of coolant in a coolant passage, and a plurality of the fins are provided intermittently along virtual waveforms extending in the flow direction and making a plurality of rows in a width direction that is orthogonal to the height direction and to the flow direction. An upstream portion of a first fin provided in a first row overlaps with the position in the flow direction f of a downstream portion of a second fin provided in a second row adjacent to the first row. Furthermore, the downstream portion of the first fin overlaps with a position in the flow direction of an upstream portion of a third fin provided in the second row.
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-228527 filed on Nov. 29, 2017, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION Field of the InventionThe present invention relates to a cooling apparatus including a plurality of fins within a coolant passage that is near a heat source body.
Description of the Related ArtAn electric automobile or hybrid automobile using an electric motor as a drive source includes a drive circuit that converts the power supplied from a high voltage power source into power for driving the motor, and supplies this power to the motor. Since the drive circuit generates heat along with the driving, a cooling apparatus is provided near the drive circuit. For example, a coolant passage including a heat sink therein is used as the cooling apparatus.
Japanese Laid-Open Patent Publication No. 2016-205802 shows a cooling apparatus that includes wave-shaped fins extending in the direction of the flow of coolant within the coolant passage. By bending the top end portion of each fin in the width direction of the coolant passage, an opening portion is formed between the downstream side end portions of the upstream side fins and the upstream side end portions of the downstream fins.
SUMMARY OF THE INVENTIONThere is a cooling apparatus in which a series of fins are provided from an upstream side to a downstream side. In this cooling apparatus, since the coolant flows while contacting the fins, it is easy for the coolant that continues flowing near the fins to accumulate heat. Therefore, a temperature boundary layer is prone to occurring near the fins on the downstream side. On the other hand, in the cooling apparatus shown in Japanese Laid-Open Patent Publication No. 2016-205802, the coolant flows while contacting the fins and becomes distanced from the fins at the opening portion. Because of this, the temperature accumulated in the coolant is cancelled for the moment. Therefore, it is difficult for the temperature boundary layer to form near the fins on the downstream side.
However, in the cooling apparatus shown in Japanese Laid-Open Patent Publication No. 2016-205802, the flow rate of the coolant in a part of the location where the fins and coolant are in contact becomes low, and in a worst case scenario, retention of the coolant occurs. In this way, although the flow of the coolant at locations distanced from the fins is maintained, the flow of the coolant near the fins becoming extremely slow, and this is referred to as separation. The heat releasing efficiency at the separation location of the flow of the coolant is reduced.
The present invention takes into consideration such a problem, and it is an object of the present invention to provide a cooling apparatus that can realize favorable heat transfer between fins and a coolant.
The present invention is a cooling apparatus comprising a plurality of fins within a coolant passage near a heat source body, wherein the plurality of fins each have a flat shape in a height direction orthogonal to a flow direction of coolant in the coolant passage, and are provided intermittently along virtual waveforms that extend in the flow direction and that make a plurality of rows in a width direction orthogonal to the flow direction and to the height direction, and with a fin provided in a first row being a first fin and two fins lined up in the flow direction and provided in a second row adjacent to the first row being a second fin and a third fin, an upstream portion including an upstream end of the first fin overlaps with a position in the flow direction of a downstream portion including a downstream end of the second fin, and a downstream portion including a downstream end of the first fin overlaps with a position in the flow direction of an upstream portion including an upstream end of the third fin.
With the above configuration, it is possible to restrict the development of the temperature boundary layer by providing the fins intermittently in the flow direction of the coolant. Furthermore, by causing the positions of the upstream portion of the first fin provided in the first row and the downstream portion of the second fin provided in the second row adjacent thereto to overlap in the flow direction and also causing the positions of the downstream portion of the first fin provided in the first row and the upstream portion of the third fin provided in the second row to overlap in the flow direction, it is possible to restrict the flow of the coolant from separating from the fins. With the structure described above, favorable heat transfer can be realized between the fins and the coolant.
In the present invention, the fins may be provided along portions of the waveforms including two peaks.
With the above configuration, development of the temperature boundary layer and separation of the flow of coolant are further restricted, and favorable heat transfer can be realized between the fins and the coolant.
In the present invention, the waveforms may have shapes symmetrical on an axis that is a virtual line that passes through the peaks, is orthogonal to the flow direction, and is parallel to the width direction.
With the above configuration, separation of the flow of coolant is further restricted, and favorable heat transfer can be realized between the fins and the coolant.
In the present invention, the fins may each have the same shape in cross-sectional planes parallel to the flow direction and to the width direction.
With the above configuration, favorable heat transfer can be realized over a wide range, with coolant flow that is substantially uniform in the height direction.
In the present invention, favorable heat transfer can be realized between the fins and the coolant.
In the present embodiment, in a case where a length of a half wavelength of the waveform in the flow direction is λ/2 and a length of the fin in the flow direction is L, [{L−(λ/2)}/λ/2]×100 may be greater than or equal to 30% and less than 50%.
With the configuration described above, the effect of preventing the occurrence of the separation is realized.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.
The following describes the present invention while providing examples of preferred embodiments and referencing the accompanying drawings.
1. Cooling Apparatus 10The cooling apparatus 10 shown in
As shown in
The inner fin 40 includes a board portion 42 brazed to the bottom cover 30 and a plurality of fins 44 that protrude upward from the board portion 42. The bottom surface of the board portion 42 is brazed to the top surface of the bottom cover 30. The bottom surface of the top cover 20 is brazed to the top end of the side wall 32 of the bottom cover 30, or contacts the top end of each fin 44. In this way, a coolant passage 12 through which coolant flows is formed by the bottom cover 30 and the top cover 20, and a plurality of fins 44 are provided within the coolant passage 12. The flow direction f of the coolant in the coolant passage 12 is substantially parallel to the longitudinal direction.
2. Fins 44In the present embodiment, the shape and arrangement of the fins 44 are one characteristic. The shape and arrangement of the fins 44 are described using
As shown in
Each fin 44 is provided intermittently along the waveform 60. In other words, in a single waveform 60, a gap 46 is provided between the two fins 44 in front and behind along the flow direction f, and the fins 44 and gaps 46 are arranged in a row in an alternating manner. One wavelength of the waveform 60 is formed by combining one fin 44 and one gap 46 that are adjacent to each other.
The fin 44 is formed along a portion of the waveform 60 including two peaks 62. The portion of the fin 44 arranged on the peak 62 on the upstream side is referred to as an upstream side peak portion 48, and the portion of the fin 44 formed on the peak 62 on the downstream side is referred to as a downstream side peak portion 50. The portion of the fin 44 arranged farthest on the upstream side in the flow direction f is referred to as the upstream end 52, and the portion of the fin 44 arranged farthest on the downstream side is referred to as the downstream end 54. The upstream end 52 is at a position resulting from the fin 44 being extended to the upstream side from the upstream side peak portion 48 along the waveform 60, and the downstream end 54 is at a position resulting from the fin 44 being extended to the downstream side from the downstream side peak portion 50 along the waveform 60. Therefore, the length L of the fin 44 in the flow direction f is greater than the length λ/2 of the half wavelength of the waveform 60. Details of the extension amount by which the fin 44 extends from the upstream side peak portion 48 to the upstream end 52 and the extension amount by which the fin 44 extends from the downstream side peak portion 50 to the downstream end 54 are provided in section [4] below.
There are two arrangement patterns for the fins 44 and the gaps 46. One of these arrangement patterns is a first pattern in which the position of the fin 44 in the width direction is displaced in one direction (e.g., to an upward direction in the plane of the drawing of
In a fin 44, the portion from the upstream side peak portion 48 to the upstream end 52 and the portion having line symmetry with respect to this portion using the virtual line 70 as an axis are referred to collectively as the upstream portion 56. Furthermore, in a fin 44, the portion from the downstream side peak portion 50 to the downstream end 54 and the portion having line symmetry with respect to this portion using the virtual line 70 as an axis are referred to collectively as a downstream portion 58. The upstream portion 56 of the fin 44 arranged in the first row 72 overlaps with the position of the downstream portion 58 of a fin 44 arranged in the second row 74 in the flow direction f. The downstream portion 58 of a fin 44 arranged in the first row 72 overlaps with the position of the upstream portion 56 of a fin 44 arranged in the second row 74 in the flow direction f.
Each fin 44 has a constant height from the upstream end 52 to the downstream end 54, and has a flat shape in the height direction in accordance with the cooling apparatus 10. Furthermore, the fins 44 have the same shape in each of cross-sectional planes parallel to both the flow direction f and the width direction. In other words, the fins 44 have the same shapes as seen in the plan view of
As shown in
According to
As described below, the extension amount is shown as a percentage of the half wavelength (=λ/2) of a waveform 60.
Extension Percentage=[{L−(λ/2)}/λ/2]×100(0%<Extension Percentage<50%)
According to
The length of a fin 44 in the width direction, i.e., the length of the fin 44 from the upstream side peak portion 48 to the downstream side peak portion 50 in the width direction, is referred to as the amplitude of the fin 44.
In the embodiment described above, the fins 44 are described as having waveforms 60 that are sinusoidal curves. Instead of this, the same effect as in the embodiment described above can be realized with fins 44 having other waveforms 60. For example, as shown in
The fins 44 each have a flat shape in the height direction orthogonal to the flow direction f of the coolant in the coolant passage 12, and are provided intermittently along the virtual waveforms 60 that extend in the flow direction f and that make a plurality of rows in the width direction orthogonal to the flow direction f and to the height direction. With the fin 44 provided in the first row 72 being the first fin 44 and the two fins 44 lined up in the flow direction f and provided in the second row 74 adjacent to the first row 72 being the second fin 44 and the third fin 44, the upstream portion 56 including the upstream end 52 of the first fin 44 overlaps with the position in the flow direction f of the downstream portion 58 including the downstream end 54 of the second fin 44. Furthermore, the downstream portion 58 including the downstream end 54 of the first fin 44 overlaps with a position in the flow direction f of the upstream portion 56 including the upstream end 52 of the third fin 44.
With the configuration described above, it is possible to restrict the development of the temperature boundary layer by providing the fins 44 intermittently in the flow direction f of the coolant. Furthermore, by causing the positions of the upstream portion 56 of the first fin 44 provided in the first row 72 and the downstream portion 58 of the second fin 44 provided in the second row 74 adjacent thereto to overlap in the flow direction f and also causing the positions of the downstream portion 58 of the first fin 44 provided in the first row 72 and the upstream portion 56 of the third fin 44 provided in the second row 74 to overlap in the flow direction f, it is possible to restrict the flow of the coolant from separating from the fins 44. With the structure described above, favorable heat transfer can be realized between the fins 44 and the coolant.
The fins 44 are provided along portions of the waveforms 60 including two peaks 62. With the configuration described above, development of the temperature boundary layer and separation of the flow of coolant are further restricted, and favorable heat transfer can be realized between the fins 44 and the coolant.
The waveforms 60 each have shapes symmetrical on the axis that is the virtual line 70 that passes through the peaks 62, is orthogonal to the flow direction f, and is parallel to the width direction. With the configuration described above, the separation of the flow of coolant is further restricted, and favorable heat transfer can be realized between the fins 44 and the coolant.
The fins 44 each have the same shape in the cross-sectional planes parallel to the flow direction f and to the width direction. With the configuration described above, favorable heat transfer can be realized over a wide range, with coolant flow that is substantially uniform in the height direction.
In a case where the length of a half wavelength of the waveform 60 in the flow direction f is λ/2 and the length of the fin 44 in the flow direction f is L, [{L−(λ/2)}/λ/2]×100 may be greater than or equal to 30% and less than 50%. With the configuration described above, the effect of preventing the occurrence of the separation 80 is realized.
The cooling apparatus according to the present embodiment is not limited to the embodiments described above, and it is obvious that various configurations can be adopted without deviating from the scope of the present invention.
Claims
1. A cooling apparatus comprising a plurality of fins within a coolant passage near a heat source body,
- wherein the plurality of fins each have a flat shape in a height direction orthogonal to a flow direction of coolant in the coolant passage, and are provided intermittently along virtual waveforms that extend in the flow direction and that make a plurality of rows in a width direction orthogonal to the flow direction and to the height direction, and
- with a fin provided in a first row being a first fin and two fins lined up in the flow direction and provided in a second row adjacent to the first row being a second fin and a third fin, an upstream portion including an upstream end of the first fin overlaps with a position in the flow direction of a downstream portion including a downstream end of the second fin, and a downstream portion including a downstream end of the first fin overlaps with a position in the flow direction of an upstream portion including an upstream end of the third fin.
2. The cooling apparatus according to claim 1, wherein the fins are provided along portions of the waveforms including two peaks.
3. The cooling apparatus according to claim 2, wherein the waveforms have shapes symmetrical on an axis that is a virtual line that passes through the peaks, is orthogonal to the flow direction, and is parallel to the width direction.
4. The cooling apparatus according to claim 1, wherein the fins each have the same shape in cross-sectional planes parallel to the flow direction and to the width direction.
5. The cooling apparatus according to claim 1, wherein in a case where a length of a half wavelength of the waveform in the flow direction is λ/2 and a length of the fin in the flow direction is L, [{L−(λ/2)}/λ/2]×100 is greater than or equal to 30% and less than 50%.
Type: Application
Filed: Nov 27, 2018
Publication Date: May 30, 2019
Inventors: Yuji ONO (WAKO-SHI), Hidetoshi KIMISHIMA (WAKO-SHI)
Application Number: 16/201,366