WO2024128303A1

WO2024128303A1 - Heat dissipating structure and method for manufacturing same

Info

Publication number: WO2024128303A1
Application number: PCT/JP2023/044968
Authority: WO
Inventors: 洋平岩垣; 淳一中野; 才司上津原
Original assignee: 日本発條株式会社
Priority date: 2022-12-16
Filing date: 2023-12-15
Publication date: 2024-06-20

Abstract

This heat dissipating structure includes a tubular body including a curved outer peripheral surface, and a plurality of fins arranged on the outer peripheral surface, wherein: each of the plurality of fins includes a base portion joined to the outer peripheral surface, and a main body portion which is connected to the base portion and which extends in a first direction moving away from the outer peripheral surface; and in a cross-sectional view from a second direction in which an axis of a tubular shape of the tubular body extends, a width of the base portion is greater than a width of the main body portion. A welding bead region may be included between the outer peripheral surface and the base portion. The base portion and the main body portion may be formed from one plate-shaped member. Each of the plurality of fins may have an L-shape in the cross-sectional view.

Description

Heat dissipation structure and manufacturing method thereof

One embodiment of the present invention relates to a heat dissipation structure having a cooling function. Also, one embodiment of the present invention relates to a method for manufacturing a heat dissipation structure having a cooling function.

Electric motors such as motors, inverters, pumps, and compressors generate heat when in operation, so fins for heat dissipation are sometimes attached to the case that houses the motor. For example, Patent Document 1 discloses a cylindrical motor case provided with multiple fins. This motor case is manufactured by extruding aluminum.

JP 2019-22250 A

In recent years, there has been a demand for further reductions in the manufacturing costs of heat dissipation structures while improving their heat dissipation properties and maintaining their mechanical strength.

In view of the above problems, one embodiment of the present invention has an object to provide a heat dissipation structure with a novel structure. Another object of one embodiment of the present invention is to provide a method for manufacturing a heat dissipation structure with a novel structure.

The heat dissipation structure according to one embodiment of the present invention includes a cylindrical body having a curved outer peripheral surface and a number of fins arranged on the outer peripheral surface, each of the fins including a base joined to the outer peripheral surface and a main body connected to the base and extending in a first direction away from the outer peripheral surface, and when viewed in cross section from a second direction in which the cylindrical axis of the cylindrical body extends, the width of the base is greater than the width of the main body.

It may include a weld bead region between the outer periphery and the base.

The outer peripheral surface and the base may be joined by solid-state diffusion bonding.

The base and main body may be formed from a single plate-like member.

In cross-sectional view, each of the fins may have an L-shape. The end of the base may include a notch.

In cross-sectional view, each of the fins may have a U-shape.

The plurality of fins may include a first fin and a second fin, and the first fin and the second fin may be arranged in the second direction. The first fin and the second fin may be arranged in a staggered manner in the second direction.

The base may include a smooth surface that is joined to the outer periphery.

The joining surface of the base that is joined to the outer peripheral surface may be curved to match the shape of the outer peripheral surface.

In cross-sectional view, each of the fins may have a T-shape.

A first fin and a second fin that are adjacent to each other among the multiple fins may be arranged such that the end of the base of the first fin faces the end of the base of the second fin.

The heat dissipation structure according to one embodiment of the present invention includes a cylindrical body having a curved outer peripheral surface and a number of fins arranged on the outer peripheral surface, each of the fins including a base portion joined to the outer peripheral surface and a number of main body portions connected to the base portion and extending in a first direction away from the outer peripheral surface, and when viewed in cross section from a second direction in which the cylindrical axis of the cylindrical body extends, the width of the base portion is greater than the width of one of the main body portions included in the number of main body portions.

In a cross-sectional view, the width of one base portion is greater than twice the width of one of the body portions included in the plurality of body portions, and in a cross-sectional view, each of the plurality of fins may have a U-shape. The plurality of body portions may be arranged in a staggered pattern in the second direction.

The material of the multiple fins may be the same as the material of the cylindrical body.

A method for manufacturing a heat dissipation structure according to one embodiment of the present invention includes fixing the position of a cylindrical body including a curved outer peripheral surface, placing a base of a fin including a base and a main body portion connected to the base on the outer peripheral surface, and joining the base to the outer peripheral surface using welding, whereby the width of the base is greater than the width of the main body portion when viewed in cross section from the direction in which the cylindrical axis of the cylindrical body extends.

The welding may be one of laser welding, arc welding, and electron beam welding.

In welding, a laser light, an arc, or an electron beam may be applied to at least the base.

In welding, a laser beam, an arc, or an electron beam may be irradiated onto the inner surface of the cylindrical body.

In welding, a laser light, an arc, or an electron beam may be applied to at least one of the upper and lower surfaces.

The method for manufacturing the heat dissipation structure may further include processing fins including a base and a main body from a single plate-like member.

The method for manufacturing the heat dissipation structure may further include processing the joining surface of the base that is joined to the outer peripheral surface into a curved shape that matches the shape of the outer peripheral surface.

In cross section, the fin may have an L-shape.

In cross section, the fins may have a T-shape.

The material of the fins may be the same as the material of the cylindrical body.

At least one of the surface, end, and side of the main body may include at least one shaped portion selected from a groove, a recess, and a protrusion.

The heat dissipation structure according to one embodiment of the present invention is manufactured by welding together a cylindrical body and fins that are processed as separate parts. The shapes of the cylindrical body and fins are not complex and are easy to form. Furthermore, even for fins with complex shapes, the processing method is not limited, and the fins can be mass-produced by applying an inexpensive processing method. Therefore, a heat dissipation structure in which a cylindrical body and fins are joined can reduce manufacturing costs. Furthermore, it is possible to increase the length of the fins and arrange them at narrow intervals, which increases the surface area and improves heat dissipation.

1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic top view showing a configuration of a heat dissipation structure according to an embodiment of the present invention; FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present invention. FIG. 4 is a flowchart showing a method for manufacturing a heat dissipation structure according to one embodiment of the present invention. 5A to 5C are cross-sectional views showing a method for manufacturing a heat dissipation structure according to one embodiment of the present invention. 5A to 5C are cross-sectional views showing a method for manufacturing a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. 2 is a schematic cross-sectional view showing the arrangement of fins of a heat dissipation structure according to one embodiment of the present invention; FIG. 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present invention. FIG. FIG. 2 is a schematic top view showing the arrangement of fins of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic top view showing the arrangement of fins of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. 1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic top view showing a configuration of a heat dissipation structure according to an embodiment of the present invention; 1 is a schematic perspective view showing a configuration of a heat dissipation structure according to one embodiment of the present invention; 5A to 5C are cross-sectional views showing a method for manufacturing a heat dissipation structure according to one embodiment of the present invention. 5A to 5C are cross-sectional views showing a method for manufacturing a heat dissipation structure according to one embodiment of the present invention. 1 is a schematic top view showing a configuration of a heat dissipation structure according to an embodiment of the present invention; FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present 2 is a schematic cross-sectional view showing a configuration of a fin of a heat dissipation structure according to one embodiment of the present invention. FIG. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing a configuration of fins of a heat dissipation structure according to one embodiment of the present invention. 1 is a schematic top view showing a configuration of a heat dissipation structure according to an embodiment of the present invention; 1 is a schematic perspective view showing a configuration of a corrugated fin of a heat dissipation structure according to one embodiment of the present invention; 1 is a schematic cross-sectional view showing a configuration of a corrugated fin of a heat dissipation structure according to one embodiment of the present invention. 1 is a schematic plan view showing a configuration of a corrugated fin of a heat dissipation structure according to an embodiment of the present invention; 1 is a schematic plan view showing a configuration of a corrugated fin of a heat dissipation structure according to an embodiment of the present invention;

Each embodiment of the invention disclosed in this application will be described below with reference to the drawings. However, the present invention can be embodied in various forms without departing from the gist of the invention, and should not be interpreted as being limited to the description of the embodiments exemplified below.

In order to make the explanation clearer, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but this is merely an example and does not limit the interpretation of the present invention. Furthermore, in this specification and drawings, elements with similar functions to those explained in the previous figures may be given the same reference numerals and duplicate explanations may be omitted.

In this specification and drawings, the same reference numeral is used to collectively represent multiple identical or similar components, and when each of these multiple components is to be distinguished from the others, a capital alphabet is added to the reference numeral. When multiple parts of a single component are to be distinguished from each other, the same reference numeral is used, followed by a hyphen and a natural number.

First Embodiment
A heat dissipation structure 100 according to an embodiment of the present invention and a method for manufacturing the same will be described with reference to FIGS. 1A to 4B.

[1. Configuration of heat dissipation structure 100]
The configuration of a heat dissipation structure 100 according to one embodiment of the present invention will be described with reference to FIGS. 1A to 2B.

FIGS. 1A and 1B are schematic perspective and top views, respectively, showing the configuration of a heat dissipation structure 100 according to one embodiment of the present invention.

1A and 1B, the heat dissipation structure 100 includes a cylindrical body 102 and a plurality of fins 104. The plurality of fins 104 are disposed on the curved outer peripheral surface of the cylindrical body 102 and extend in a direction away from the outer peripheral surface. Although not shown, a flow path for circulating a refrigerant for cooling the heat dissipation structure 100 may be provided inside (i.e., on the inner peripheral surface side of the cylindrical body 102) or outside (i.e., outside the plurality of fins 104) of the heat dissipation structure 100. In the following description, the direction in which the cylindrical axis of the cylindrical body 102 extends is defined as the z direction, and directions perpendicular to the z direction and perpendicular to each other are defined as the x direction and the y direction. Therefore, each of the plurality of fins 104 is disposed parallel to the z direction on the outer peripheral surface of the cylindrical body 102, and extends radially from the outer peripheral surface of the cylindrical body 102 in a predetermined direction in the xy plane.

The surface of the cylindrical body 102 includes an upper surface and a lower surface that connect the inner and outer surfaces, in addition to the inner and outer surfaces. Since the upper and lower surfaces have the same configuration, in the following, when the upper and lower surfaces are not particularly distinguished from each other, the upper or lower surface may be simply referred to as a side surface. Various electric motors are housed on the inner surface side of the cylindrical body 102. Therefore, the cylindrical body 102 functions as a housing that protects the electric motors. In addition, the cylindrical body 102 can absorb heat radiated from the electric motors housed on the inner surface side of the cylindrical body 102. In a cross-sectional view from the z direction, the cylindrical body 102 has a circular ring shape (here, the cross-sectional view of the cylindrical body 102 is the same as the top view shown in FIG. 1B, so the cross-sectional view of the cylindrical body 102 is omitted.). However, the cross-sectional shape of the cylindrical body 102 is not limited to this. The cross-sectional shape of the cylindrical body 102 is appropriately selected according to the type or size of the electric motor housed on the inner peripheral side of the cylindrical body 102. The size of the cylindrical body 102 (outer diameter and length in the z direction) is also appropriately selected according to the type or size of the electric motor. For example, the outer diameter may be 200 mm or more and 500 mm or less, and the length in the z direction may be 30 mm or more and 300 mm or less. The aspect ratio (outer diameter/length) of the cylindrical body 102 may be, for example, 1 or more and 20 or less. The thickness of the cylindrical body 102 (the distance between the inner peripheral surface and the outer peripheral surface) is also appropriately selected according to the strength required for the heat dissipation structure 100, and is, for example, in the range of 1 mm or more and 20 mm or less, but is not limited thereto.

The fins 104 are connected to the cylindrical body 102 and can dissipate heat conducted from the cylindrical body 102 to the outside. That is, the fins 104 function as a heat sink. The thickness and height of the fins 104 (the length in the direction in which the fins 104 extend from the outer circumferential surface of the cylindrical body 102), the number of fins 104, and the spacing between the fins 104 are appropriately selected according to the cooling efficiency required of the heat dissipation structure 100. For example, the thickness of the fins 104 may be in the range of 0.5 mm to 5 mm, and the height may be in the range of 30 mm to 90 mm. The spacing between the fins 104 is, for example, 1 mm to 20 mm, but is not limited to this.

The multiple fins 104 are arranged at equal intervals over the entire outer circumferential surface of the cylindrical body 102. However, the arrangement of the multiple fins 104 is not limited to this. Although not shown, the multiple fins 104 may be arranged at irregular intervals over the outer circumferential surface of the cylindrical body 102, or may be arranged on only a portion of the outer circumferential surface of the cylindrical body 102.

The length of the fins 104 in the z direction is the same as the length of the cylindrical body 102 in the z direction. However, the length of the fins 104 is not limited to this. Although not shown, the length of the fins 104 in the z direction may be greater or smaller than the length of the cylindrical body 102 in the z direction.

The material of the fins 104 may be the same as or different from the material of the cylindrical body 102. However, in order to maintain the mechanical strength of the heat dissipation structure 100, it is preferable that the material of the fins 104 is the same as the material of the cylindrical body 102. An aluminum alloy can be used as the material of each of the cylindrical body 102 and the fins 104. For example, the aluminum alloy is an alloy containing aluminum, zinc, magnesium, and copper, such as A7072, A7050, A7075, and A7N01, or an alloy of aluminum and magnesium containing silicon, such as A6061, A6063, and A6N01. However, the aluminum alloy is not limited to the above alloys, and may be an alloy of aluminum and magnesium called A5052, A5056, A5083, A5454, etc., an alloy of aluminum containing silicon called A4032, A4043, etc., or an alloy of aluminum and manganese called A3003, A3005, A3105, etc. By using an aluminum alloy for the cylindrical body 102 and the fins 104, the heat dissipation structure 100 can exhibit high heat dissipation characteristics due to the high thermal conductivity of aluminum.

The configuration of the fins 104 will now be described further with reference to Figures 2A and 2B. Figures 2A and 2B are schematic perspective and cross-sectional views, respectively, showing the configuration of the fins 104 of the heat dissipation structure 100 according to one embodiment of the present invention. Specifically, Figure 2B is a cross-sectional view of the fins 104 cut along line A1-A2 shown in Figure 2A.

2A and 2B, the fin 104 includes a base 104-1 having a first width w1 in a first direction d1 and a main body 104-2 extending in a second direction d2 intersecting the first direction d1. Here, each of the first direction d1 and the second direction d2 is a direction in the xy plane, and the second direction d2 corresponds to the direction in which the fin 104 extends from the outer peripheral surface of the cylindrical body 102. The base 104-1 includes a bent portion CR1, and the main body 104-2 is connected to the base 104-1 via the bent portion CR1. The fin 104 has a structure in which one plate-shaped member is bent, and in a cross-sectional view, each of the base 104-1 and the main body 104-2 includes one end. That is, in a cross-sectional view, the fin 104 has an L-shape. The angle between the first direction d1 and the second direction d2 is preferably, for example, approximately 90°, but is not limited to this. For example, the angle between the first direction d1 and the second direction d2 may be 45° or more and 135° or less. Note that the connection between the base 104-1 and the main body 104-2 can be a structure in which two members are joined, other than a structure in which one plate-like member is bent, and does not necessarily have to include the bent portion CR1.

The processing method of the fin 104 is not particularly limited, but the fin 104 can be processed, for example, by press punching or by bending a plate-shaped member. Since the fin 104 has a simple shape, an inexpensive processing method can be adopted for processing the fin 104. The fin 104 can also be formed by joining the plate-shaped members constituting the base 104-1 and the main body 104-2. When joining two plate-shaped members, the base 104-1 of the fin 104 does not need to include the bent portion CR1, and the plate-shaped member constituting the main body 104-2 can be connected onto the plate-shaped member constituting the base 104-1. The joining of the base 104-1 and the main body 104-2 can be performed, for example, by laser welding, arc welding, electron beam welding, solid-state diffusion bonding, brazing, or the like. Examples of brazing filler that can be used include alloys containing silver, copper, and zinc, alloys containing copper and zinc, copper containing a small amount of phosphorus, alloys containing aluminum, alloys containing titanium, copper, and nickel, alloys containing titanium, zirconium, and copper, and alloys containing titanium, zirconium, copper, and nickel.

In a cross-sectional view, the first width w1 of the base 104-1 in the first direction d1 is larger than the second width w2 (thickness of the fins 104) of the main body 104-2 in the first direction d1. The first width w1 of the base 104-1 is equal to or smaller than the second width w2 of the main body 104-2 plus the spacing between the fins 104. For example, the first width w1 of the base 104-1 is 1.1 to 10 times, preferably 1.2 to 5 times, and more preferably 1.5 to 2 times the second width w2 of the main body 104-2. As will be described in detail later, the base 104-1 is joined to the cylindrical body 102 by welding. In the heat dissipation structure 100, the first width w1 of the base 104-1 connected to the main body 104-2 is larger than the second width w2 of the main body 104-2, so the bonding area between the base 104-1 and the cylindrical body 102 is increased compared to a configuration in which the main body 104-2 is directly bonded to the cylindrical body 102. Therefore, in the heat dissipation structure 100, the bonding strength between the cylindrical body 102 and the base 104-1 of the fin 104 is improved.

Note that Figures 1A and 1B show a configuration in which the end of the base 104-1 of one fin 104 is spaced apart from the bent portion CR1 of the base 104-1 of the other fin 104 in two adjacent fins 104. However, a configuration in which the base 104-1 of one fin 104 is in contact with the bent portion CR1 of the other fin 104 is also applicable as the configuration of the heat dissipation structure 100. In this case, the base 104-1 of one fin 104 and the bent portion CR1 of the other fin 104 may be joined.

2. Manufacturing method of heat dissipation structure 100
A method for manufacturing the heat dissipation structure 100 according to one embodiment of the present invention will be described with reference to FIGS. 3 to 4B.

FIG. 3 is a flowchart showing a method for manufacturing a heat dissipation structure 100 according to one embodiment of the present invention. Also, each of FIGS. 4A and 4B is a schematic cross-sectional view showing a method for manufacturing a heat dissipation structure 100 according to one embodiment of the present invention. Below, a description will be given according to the order of the steps in the flowchart of FIG. 3 with reference to the cross-sectional views of FIG. 4A and FIG. 4B. Although FIG. 3 shows steps S100 to S120, the method for manufacturing the heat dissipation structure 100 is not limited to this. The heat dissipation structure 100 may be manufactured by a manufacturing method including additional steps.

In step S100, the position of the cylindrical body 102 is fixed. The position of the cylindrical body 102 needs to be fixed so that the fins 104 can be placed on the outer circumferential surface in step S110, which will be described later. For example, the cylindrical body 102 is placed on a stage and its position is fixed. The cylindrical body 102 may be fixed by suction or by magnetic force. The cylindrical body 102 may also be fixed by being grasped. If the cylindrical body 102 is fixed by being grasped, the cylindrical body 102 does not need to be placed on a stage.

In step S110, the fins 104 are placed on the outer circumferential surface of the cylindrical body 102 (see FIG. 4A). The fins 104 are placed so that the joining surface of the base 104-1 (the surface facing the outer circumferential surface of the cylindrical body 102) is in contact with the outer circumferential surface of the cylindrical body 102. It is preferable that the joining surface of the base 104-1 is a smooth surface without protrusions or the like so that the entire joining surface is joined to the outer circumferential surface of the cylindrical body 102. It is also preferable that the fins 104 placed on the outer circumferential surface of the cylindrical body 102 are fixed.

In step S120, the laser light is scanned in the z direction while irradiating the base 104-1 (see FIG. 4B). The laser light is irradiated from the outer peripheral surface side of the cylindrical body 102. This bonds the base 104-1 of the fin 104 to the outer peripheral surface of the cylindrical body 102. In other words, step S120 is a laser welding step for bonding the fin 104 to the cylindrical body 102. As the laser light, for example, an yttrium-aluminum-garnet (YAG) laser having a wavelength of 1064 nm, or a fiber laser having a wavelength of 1070 nm, can be used. Laser light processed into a linear pattern using an optical element can also be used.

Note that a weld bead may be formed in the portion where the laser welding was performed in step S120. For example, a weld bead region may be included between the base 104-1 and the outer circumferential surface of the cylindrical body 102.

By repeating steps S100 to S120, multiple fins 104 are bonded onto the outer circumferential surface of the cylindrical body 102, and the heat dissipation structure 100 is manufactured.

As a further step, a post-weld heat treatment of the heat dissipation structure 100 may be performed. The post-weld heat treatment can reduce residual stress due to the joining of the tubular body 102 and the fins 104. The post-weld heat treatment also improves the ductility, toughness, and corrosion resistance of the heat dissipation structure 100. The post-weld heat treatment is, for example, but is not limited to, a solution treatment or an aging treatment, or a solution aging treatment that is a combination of these treatments. The post-weld heat treatment is appropriately selected depending on the materials of the tubular body 102 and the fins 104.

As a further step, a weld bead removal process may be performed in the weld bead area formed by welding. The weld bead can be removed, for example, by cutting.

Note that, although the above describes a configuration in which the fins 104 are joined to the cylindrical body 102 using laser welding, the welding for joining the fins 104 to the cylindrical body 102 is not limited to laser welding. For example, in addition to laser welding, arc welding or electron beam welding can also be used. Laser welding, arc welding, and electron beam welding are so-called fusion welding, but solid-state diffusion bonding or brazing can also be used.

In this embodiment, various modifications of the configuration of the heat dissipation structure 100 are possible. Below, several modified examples of the heat dissipation structure 100 are described with reference to Figures 5A to 15. Note that, below, descriptions of configurations similar to those described above will be omitted.

<Modification 1>
Fig. 5A is a schematic perspective view showing the configuration of the fins 104A of the heat dissipation structure 100A according to one embodiment of the present invention. Fig. 5B is a schematic cross-sectional view showing the arrangement of the fins 104A of the heat dissipation structure 100A according to one embodiment of the present invention.

As shown in FIG. 5A, the base 104A-1 of the fin 104A includes a notch 104A-1a in which a corner of the end portion is cut out along the z direction. The size of the notch 104A-1a is not particularly limited. Furthermore, the cross-sectional shape of the notch 104A-1a may be linear as shown in FIG. 5B, or may be curved (not shown).

In FIG. 5B, two adjacent fins 104A are arranged so that they overlap. Specifically, the fins 104 are arranged so that the bent portion CR1 of the base 104A-1 of one of the two adjacent fins 104 is located on the notch portion 104A-1a of the base 104A-1 of the other of the two adjacent fins 104. In this way, since the base 104A-1 of the fin 104A includes the notch portion 104A-1a, the fin 104 adjacent to the fin 104A can be arranged so that it overlaps. Therefore, in the heat dissipation structure 100A, the spacing between the fins 104A can be made smaller.

<Modification 2>
FIG. 6 is a schematic cross-sectional view showing the configuration of a fin 104B of a heat dissipation structure 100B according to one embodiment of the present invention.

As shown in FIG. 6, the joint surface of the base 104B-1 of the fin 104B (the surface facing the outer peripheral surface of the cylindrical body 102) is curved to match the shape of the outer peripheral surface of the cylindrical body 102 (see region B in FIG. 6). In other words, the joint surface of the base 104B-1 is a curved, smooth surface. Therefore, when the fin 104B is placed on the outer peripheral surface of the cylindrical body 102, the contact area between the outer peripheral surface of the cylindrical body 102 and the base 104B-1 increases. In other words, the gap between the base 104B-1 and the outer peripheral surface of the cylindrical body 102 becomes smaller. Therefore, in the heat dissipation structure 100B, welding defects in welding are reduced, and the joint strength between the cylindrical body 102 and the base 104B-1 of the fin 104B is further improved.

<Modification 3>
7A and 7B are schematic cross-sectional views showing the configuration of a fin 104C of a heat dissipation structure 100C according to one embodiment of the present invention.

As shown in FIG. 7A, the fin 104C includes a base 104C-1 having a first width w1 in a first direction d1 and a body 104C-2 extending in a second direction d2 intersecting the first direction d1. The body 104C-2 is connected to the upper surface (the surface opposite to the joint surface) of the base 104C-1. The base 104C-1 includes two ends in the first direction d1, and the body 104C-2 includes one end in the second direction d2. That is, in a cross-sectional view, the fin 104C has a T-shape. The angle between the first direction d1 and the second direction d2 is preferably, for example, approximately 90°, but is not limited to this. For example, the angle between the first direction d1 and the second direction d2 may be 45° or more and 135° or less.

The fins 104C can be formed, for example, by extrusion molding or by joining the plate-like members that make up the base 104C-1 and the main body 104C-2.

Also, as shown in FIG. 7B, the fin 104C may have a configuration in which the body portions 104-2 of two fins 104 (i.e., fins 104 having an L-shaped cross section) are joined together to form a T-shaped cross section. In this case, the base portion 104C-1 of the fin 104C includes two base portions 104-1, and the body portion 104C-2 of the fin 104C includes two body portions 104-2. Note that a weld bead region may be included between the two body portions 104-2.

Because the first width w1 of the base 104C-1 is larger than the second width w2 of the main body 104C-2 (see FIG. 7A), the bonding area between the base 104C-1 and the cylindrical body 102 is increased compared to a configuration in which the main body 104C-2 is directly bonded to the cylindrical body 102. As a result, the bonding strength between the cylindrical body 102 and the base 104C-1 of the fin 104C is improved in the heat dissipation structure 100C as well.

<Modification 4>
8A and 8B are schematic top views showing the arrangement of the fins 104 of a heat dissipation structure 100D according to an embodiment of the present invention. Specifically, FIG. 8B is an enlarged top view of a region D in FIG. 8A.

As shown in Figures 8A and 8B, in the heat dissipation structure 100D, the ends of the bases 104-1 of two adjacent fins 104 are arranged on the outer circumferential surface of the cylindrical body 102 so that they face each other, or the bent portions CR1 of the bases 104-1 of two adjacent fins 104 face each other. In other words, the two adjacent fins 104 are arranged symmetrically so that they face in opposite directions.

In FIG. 8A, the fins 104 are arranged regularly so that every other fin faces the same direction, but the arrangement of the fins 104 in the heat dissipation structure 100D is not limited to this. The heat dissipation structure 100D may include at least one pair of adjacent fins arranged symmetrically so that the fins face in opposite directions. The heat dissipation structure 100D also improves the bonding strength between the cylindrical body 102 and the base 104-1 of the fin 104.

In addition, in the heat dissipation structure 100D, the ends of two adjacent bases 104-1 may be joined together.

<Modification 5>
Each of FIGS. 9A to 9C is a schematic perspective view showing the configuration of a fin 104E of a heat dissipation structure 100E according to one embodiment of the present invention.

Figure 9A shows a fin 104E in which a groove 104E-2a is formed on the surface of the main body 104E-2. Figure 9B shows a fin 104E in which a recess 104E-2b is formed on the surface of the main body 104E-2. Figure 9C shows a fin 104E in which a convex portion 104E-2c is formed on the surface of the main body 104E-2. The number or size of each of the grooves 104E-2a, recesses 104E-2b, and convex portions 104E-2c is selected appropriately and is not particularly limited. In addition, the cross-sectional shape of each of the grooves 104E-2a, recesses 104E-2b, and convex portions 104E-2c is, for example, rectangular, semicircular, or semi-elliptical, but is not limited to these. In addition, the grooves 104E-2a, the recesses 104E-2b, and the protrusions 104E-2c can be formed not only on one surface of the main body 104E-2, but also on both surfaces of the main body 104E-2. Furthermore, the fins 104E can be configured by combining multiple shaped portions selected from the grooves 104E-2a, the recesses 104E-2b, and the protrusions 104E-2c. In this way, by forming shaped portions having various uneven shapes on the surface of the main body 104E-2, the surface area of the main body 104E-2 is increased. This improves the heat dissipation characteristics of the fins 104E, and improves the cooling efficiency of the heat dissipation structure 100E.

Furthermore, although not shown, the fins 104E can be configured such that unevenly shaped portions are formed not only on the surface of the main body 104E-2, but also on the ends or sides of the main body 104E-2. The shaped portions formed on the main body 104E-2 of the heat dissipation structure 100E are not particularly limited. In the heat dissipation structure 100E, the cylindrical body 102 and the fins 104E are processed and joined as separate parts. Therefore, compared to the fins of the heat dissipation structure manufactured by integrally forming the cylindrical body and the fins, it is possible to form various shaped portions on the fins 104E. The processing method of the fins 104E is not particularly limited, but for example, the fins 104E can be manufactured using a processing method such as forging, casting, metal additive manufacturing, or cutting, or a combination of these.

<Modification 6>
10A to 13, further structural modifications of the heat dissipation structure 100 will be described. In the description of Fig. 10A to 13, although there are structural differences from the heat dissipation structure 100, the same reference numerals as the heat dissipation structure 100 will be used for convenience.

Each of Figs. 10A to 11 and 13 is a schematic perspective view showing the configuration of a heat dissipation structure 100 according to one embodiment of the present invention. Also, Fig. 12 is a top view showing a schematic configuration of a heat dissipation structure 100 according to one embodiment of the present invention. Each of Figs. 10 to 13 shows a part of the configuration of the heat dissipation structure 100.

10A, the multiple fins 104 may be arranged so that each base 104-1 is not parallel to the z direction, but is inclined from the z direction. Also, as shown in FIG. 10B, the multiple fins 104 may be arranged so that they form multiple rows in the z direction on the outer peripheral surface of the cylindrical body 102. Although not shown, the fins 104 may form a staggered arrangement on the outer peripheral surface of the cylindrical body 102. Note that the surface shape of the main body 104-2 of each fin 104 is not limited to a rectangle. For example, as shown in FIG. 11A, the outline of the main body 104-2 may be formed of straight lines and curves or only curves. In this case, the outline of the base 104-1 may also be formed of straight lines and curves or only curves. Also, as shown in FIG. 11B, each of the base 104-1 and the main body 104-2 may be bent. Furthermore, as shown in FIG. 12, the main body 104-2 of each fin 104 may have a branched structure. By providing each fin 104 with a branched structure, the area of the fin 104 is increased, enabling more efficient cooling. Also, as shown in FIG. 13, multiple main body parts 104-2 may be connected to one base part 104-1.

<Modification 7>
FIG. 14 is a cross-sectional view showing a method for manufacturing the heat dissipation structure 100 according to one embodiment of the present invention.

FIG. 14 shows a modified example of the laser welding in step S120 of FIG. 3. As shown in FIG. 14, the laser light is irradiated onto the inner peripheral surface of the cylindrical body 102. When the laser light is irradiated from the inner peripheral surface side of the cylindrical body 102, the laser light is not blocked by the fins 104 and can be scanned freely, making it easier to control the laser light.

Laser welding from the inner circumferential surface side of the cylindrical body 102 can be performed even after multiple fins 104 have been joined onto the outer circumferential surface of the cylindrical body 102. For example, if poor welding of the fins 104 is confirmed, laser light can be irradiated from the inner circumferential surface side of the cylindrical body 102 to improve the poor welding of the fins 104. In this case, the manufacturing yield of the heat dissipation structure 100 is improved, and the manufacturing cost of the heat dissipation structure 100 can be reduced.

<Modification 8>
15 is a cross-sectional view showing a method for manufacturing the heat dissipation structure 100 according to an embodiment of the present invention. In FIG. 15, a partial cross-sectional view of the heat dissipation structure 100 is cut so as not to include the main body portion 104-2, but for convenience, the main body portion 104-2 is shown by a dotted line.

FIG. 15 shows the steps of laser welding. In the laser welding shown in FIG. 15, laser light is irradiated from the z direction. Specifically, the laser light is irradiated to the base 104-1 of the fin 104 from the upper and lower sides of the cylindrical body 102. By irradiating the laser light in this manner, the base 104-1 of the fin 104 can be joined to the cylindrical body 102 on the upper and lower surfaces of the cylindrical body 102. It is preferable that the laser light is scanned in the first direction d1 at least by the first width w1 of the base 104-1.

In the laser welding shown in FIG. 15, the upper and lower surfaces of the cylindrical body 102 are irradiated with laser light, but two laser beams may be irradiated simultaneously with the upper and lower surfaces of the cylindrical body 102, or one laser beam may be irradiated to the upper surface of the cylindrical body 102 and then irradiated to the lower surface of the cylindrical body 102. Also, the laser beam may be irradiated to only one of the upper and lower surfaces of the cylindrical body 102, and laser welding may be performed on only one of the upper and lower surfaces of the cylindrical body 102.

15 may be performed before the laser welding of step S120 or after the laser welding of step S120. When the laser welding of FIG. 15 is performed before the laser welding of step S120, the base 104-1 of the fin 104 is not joined to the entire outer peripheral surface of the cylindrical body 102, but is joined to the cylindrical body 102 only near the upper and lower surfaces of the cylindrical body 102. In this case, the base 104-1 of the fin 104 is temporarily joined to the outer peripheral surface of the cylindrical body 102, and is fully joined by performing the laser welding of step S120. On the other hand, when the laser welding of FIG. 15 is performed after the laser welding of step S120, it is possible to perform joining that fills the gap between the base 104-1 of the fin 104 and the outer peripheral surface of the cylindrical body 102 near the upper and lower surfaces of the cylindrical body 102. In this way, by performing not only the laser welding in step S120 but also the laser welding shown in FIG. 15, the bonding strength between the base 104-1 of the fin 104 and the outer peripheral surface of the cylindrical body 102 is improved. Therefore, the mechanical strength of the heat dissipation structure 100 is improved.

As described above, the heat dissipation structure 100 according to one embodiment of the present invention, including the modified example, is manufactured by welding together the cylindrical body 102 and the fins 104, which are processed as separate parts. The shapes of the cylindrical body 102 and the fins 104 are not complex, and they are easy to process. Furthermore, as described in the modified example, even if the fins 104 have a complex shape, the processing method of the fins 104 is not limited, and they can be mass-produced by applying an inexpensive processing method. Therefore, the manufacturing cost can be reduced for the heat dissipation structure 100 in which the cylindrical body 102 and the fins 104 are joined together.

The heat dissipation structure 100 according to one embodiment of the present invention contains an aluminum alloy such as A7075 or A6061. Therefore, the heat dissipation structure 100 is not only able to achieve high cooling efficiency due to the high thermal conductivity of aluminum, but is also lightweight and strong. This enables application to heat dissipation structures that require high reliability, such as motors that generate propulsive power for aircraft. The heat dissipation structure 100 according to one embodiment of the present invention can also be suitably used as a heat-dissipating structure for various vehicles, such as unmanned aerial vehicles such as drones and electric vehicles, which require lightweight design.

Second Embodiment
16 to 17B, a heat dissipation structure 200 according to an embodiment of the present invention will be described. When the configuration of the heat dissipation structure 200 is similar to the configuration of the heat dissipation structure 100 described in the first embodiment, the description of the configuration may be omitted.

FIG. 16 is a schematic top view showing the configuration of a heat dissipation structure 200 according to one embodiment of the present invention.

16, the heat dissipation structure 200 includes a cylindrical body 202 and a plurality of fins 204. The plurality of fins 204 are arranged on the curved outer peripheral surface of the cylindrical body 202 and extend in a direction away from the outer peripheral surface. That is, each of the plurality of fins 204 is arranged parallel to the z-axis direction on the outer peripheral surface of the cylindrical body 202 and extends radially from the outer peripheral surface of the cylindrical body 102 in a predetermined direction in the xy plane. The plurality of fins 204 are arranged at equal intervals over the entire outer peripheral surface of the cylindrical body 202. However, the arrangement of the plurality of fins 204 is not limited to this. The plurality of fins 204 may be arranged at irregular intervals on the outer peripheral surface of the cylindrical body 202, or may be arranged on a part of the outer peripheral surface of the cylindrical body 202.

17A and 17B are schematic perspective and cross-sectional views, respectively, showing the configuration of fins 204 of a heat dissipation structure 200 according to one embodiment of the present invention. Specifically, FIG. 17B is a cross-sectional view of fins 204 cut along line B1-B2 shown in FIG. 17A.

As shown in Figures 17A and 17B, the fin 204 includes a base 204-1 having a first width w1 in a first direction d1 and two main body portions 204-2 extending in a second direction d2. The base 204-1 includes two bent portions CR1, and each of the two main body portions 204-2 is connected to the base 204-1 via the bent portions CR1. The two main body portions 204-2 are connected to the base 204-1 so as to face each other in a substantially parallel manner. The fin 204 has a structure in which both ends of a single plate-like member are bent, and has a U-shape in cross section. The lengths of the two main body portions 204-2 in the d2 direction may be the same or different.

In the heat dissipation structure 200, the base 204-1 of the fin 204 can be joined to the outer peripheral surface of the cylindrical body 202 by irradiating laser light from the inside of the U-shape of the fin 204, i.e., between the two main body portions 204-2, toward the base 204-1. Therefore, in a cross-sectional view, the first width w1 of the base 204-1 in the first direction d1 is greater than twice the second width (thickness of the fin 204) in the first direction d1 of the main body portion 204-2. For example, the first width w1 of the base 204-1 is 2.1 times or more and 20 times or less, preferably 2.2 times or more and 10 times or less, and more preferably 2.5 times or more and 5 times or less, of the second width w2 of the main body portion 204-2. In the heat dissipation structure 200, the first width w1 of the base 204-1 connected to the main body 204-2 is larger than the second width w2 of the main body 204-2, so the joint area between the base 204-1 and the cylindrical body 202 is increased compared to a configuration in which the main body 204-2 is directly joined to the cylindrical body 202. Therefore, in the heat dissipation structure 200, the joint strength between the cylindrical body 202 and the base 204-1 of the fin 204 is improved. In addition, because two main bodies 204-2 are arranged on the cylindrical body 202 by joining one base 204-1, the number of laser welding operations in the heat dissipation structure 200 can be reduced.

In this embodiment, various modifications of the configuration of the heat dissipation structure 200 are possible. Below, several modified examples of the heat dissipation structure 200 are described with reference to Figures 18 to 20. Note that the following description will be omitted for configurations similar to those described above.

<Modification 1>
FIG. 18 is a schematic cross-sectional view showing the configuration of a fin 204A of a heat dissipation structure 200A according to one embodiment of the present invention.

As shown in FIG. 18, in the fin 204A of the heat dissipation structure 200A, the two main body parts 204-2 connected to one base part 204-1 face each other, but the two main body parts 204-2 are not parallel to each other. Specifically, the distance between the two main body parts 204-2 increases with increasing distance from the base part 204-1. In the fin 204A, the space inside the U-shape of the fin 204A increases, making it easier to irradiate laser light from between the two main body parts 204-2 toward the base part 204-1.

<Modification 2>
FIG. 19 is a schematic perspective view showing the configuration of a fin 204B of a heat dissipation structure 200B according to one embodiment of the present invention.

As shown in FIG. 19, in the fin 204B of the heat dissipation structure 200B, multiple main body parts 204-2 are connected to one base part 204-1. The fin 204B has a U-shape in a plan view seen from the z direction. However, in the fin 204B, the multiple main body parts 204-2 are arranged at a distance from each other along the z direction. The arrangement of the multiple main body parts 204-2 at one end side and the other end side of the base 204-1 is the same. At each of the one end side and the other end side of the base 204-1, the multiple main body parts 204-2 are connected to the base 204-1 at equal intervals. In the fin 204B, the surface area of the main body parts 204-2 is increased by arranging the multiple main body parts 204-2. This improves the heat dissipation characteristics of the fin 204B, and improves the cooling efficiency of the heat dissipation structure 200B.

<Modification 3>
FIG. 20 is a schematic perspective view showing the configuration of a fin 204C of a heat dissipation structure 200C according to one embodiment of the present invention.

As shown in FIG. 20, in the fin 204C of the heat dissipation structure 200C, multiple body parts 204-2 are connected to one base part 204-1. The fin 204C has a U-shape in a plan view seen from the z direction. However, in the fin 204C, the multiple body parts 204-2 are arranged at a distance from each other along the z direction. The multiple body parts 204-2 are arranged in a staggered pattern on the base part 204-1 and connected to the base part 204-1. In the fin 204C, the surface area of the body parts 204-2 is increased by arranging the multiple body parts 204-2. This improves the heat dissipation characteristics of the fin 204C and improves the cooling efficiency of the heat dissipation structure 200C.

As described above, the heat dissipation structure 200 according to one embodiment of the present invention, including the modified examples, can be manufactured by welding together the cylindrical body 202 and the fins 204, which are processed as separate parts. The shapes of the cylindrical body 202 and the fins 204 are not complicated, and they are easy to process. Therefore, the heat dissipation structure 200 in which the cylindrical body 202 and the fins 204 are joined together can reduce manufacturing costs.

Third Embodiment
21 to 22B, a heat dissipation structure 300 according to an embodiment of the present invention will be described. When the configuration of the heat dissipation structure 300 is similar to the configuration of the heat dissipation structure 100 described in the first embodiment or the heat dissipation structure 200 described in the second embodiment, the description of the configuration may be omitted.

FIG. 21 is a schematic top view showing the configuration of a heat dissipation structure 300 according to one embodiment of the present invention.

21, the heat dissipation structure 300 includes a cylindrical body 302 and a corrugated fin 306. The corrugated fin 306 is disposed on the outer peripheral surface of the cylindrical body 302. The number of corrugated fins 306 is not particularly limited. The heat dissipation structure 300 includes one or more corrugated fins 306. When the heat dissipation structure 300 includes multiple corrugated fins 306, the multiple corrugated fins 306 may be disposed at equal intervals on the outer peripheral surface of the cylindrical body 302, or may be disposed at irregular intervals, or may be disposed on a portion of the outer peripheral surface of the cylindrical body 302.

22A and 22B are schematic perspective and cross-sectional views, respectively, showing the configuration of a corrugated fin 306 of a heat dissipation structure 300 according to one embodiment of the present invention. Specifically, FIG. 22B is a cross-sectional view of the corrugated fin 306 cut along line C1-C2 shown in FIG. 22A.

As shown in Figures 22A and 22B, the corrugated fin 306 includes multiple base portions 306-1, multiple main body portions 306-2, and multiple connection portions 306-3. The base portion 306-1 includes two bend portions CR1, and the connection portion 306-3 includes two bend portions CR2. The main body portion 306-2 is connected to the base portion 306-1 via the bend portion CR1 at one end, and to the connection portion 306-3 via the bend portion CR2 at the other end. However, the connection portion 306-3 is not provided at the end of the corrugated fin 306. The corrugated fin 306 has a structure in which a single plate-shaped member is bent to include multiple mountain shapes and valley shapes, and has a wave shape in a cross-sectional view.

In the heat dissipation structure 300, the base 306-1 of the corrugated fin 306 can be joined to the outer peripheral surface of the cylindrical body 302 by irradiating laser light from between the two main body parts 306-2 that form the corrugated fin valley shape toward the base part 306-1. The corrugated fin 306 has two adjacent main body parts 306-2 connected via a connecting part 306-3, which makes it easy to align the main body part 306-2 on the outer peripheral surface of the cylindrical body 302 during laser welding.

In this embodiment, various modifications of the configuration of the heat dissipation structure 300 are possible. Below, one modified example of the heat dissipation structure 300 is described with reference to Figures 23A and 23B. Note that, below, a description of the same configuration as that described above will be omitted.

<Modification>
23A and 23B are schematic plan views showing a configuration of a corrugated fin 306A of a heat dissipation structure 300A according to one embodiment of the present invention. Each of Fig. 23A and Fig. 23B shows a plan view of two adjacent main body portions 306-2.

23A and 23B, in the corrugated fin 306A, a plurality of openings OP are provided in the main body portion 306-2. The plurality of openings OP are arranged in the z-axis direction, and each of the plurality of openings OP has a substantially rectangular shape with a long side along the second direction d2. In the corrugated fin 306A shown in FIG. 23A, the arrangement of the openings OP provided in two adjacent main body portions 306-2 is the same. Therefore, in the corrugated fin 306A shown in FIG. 23A, the openings OP provided in the two main body portions 306-2 overlap. On the other hand, in the corrugated fin 306A shown in FIG. 23B, the arrangement of the openings OP is different in the two adjacent main body portions 306-2. Specifically, the plurality of openings OP are provided in the main body portion 306-2 such that one opening of the other of the two adjacent main body portions 306-2 is located between two openings OP of one of the two adjacent main body portions 306-2. In the corrugated fin 306 shown in FIG. 23B, the number of openings OP may differ between two adjacent main body portions 306-2.

As described above, the heat dissipation structure 300 according to one embodiment of the present invention, including the modified examples, can be manufactured by welding together the cylindrical body 302 and the corrugated fins 306, which are processed as separate parts. The shapes of the cylindrical body 302 and the corrugated fins 306 are not complex, and they are easy to process. Therefore, the heat dissipation structure 300 in which the cylindrical body 302 and the corrugated fins 306 are joined together can reduce manufacturing costs.

The above-mentioned embodiments of the present invention may be combined as appropriate to the extent that they are not mutually inconsistent. Furthermore, products in which a person skilled in the art appropriately adds or deletes components or modifies the design based on each embodiment are also included within the scope of the present invention as long as they incorporate the gist of the present invention.

Furthermore, even if there are other effects and advantages different from those brought about by the above-mentioned embodiments, if they are clear from the description in this specification or can be easily predicted by a person skilled in the art, they are naturally understood to be brought about by the present invention.

100, 100A, 100B, 100C, 100D, 100E, 200, 200A, 200B, 200C, 300, 300A: heat dissipation structure,
102, 202, 302: cylindrical body,
104, 104A, 104B, 104C, 104E, 204, 204A, 204B, 204C: fins,
104-1, 104A-1, 104B-1, 104C-1, 204-1: base,
104-2, 104C-2, 104E-2, 204-2: main body,
104A-1a: notch portion,
104E-2a: groove portion,
104E-2b: recess,
104E-2c: convex portion,
306, 306A: Corrugated fin,
306-1: Base,
306-2: main body,
306-3: Connection part,
CR1, CR2: bending portion,
OP: Opening

Claims

A cylindrical body including a curved outer circumferential surface;
a plurality of fins disposed on the outer circumferential surface;
Each of the plurality of fins is
A base portion joined to the outer circumferential surface;
a body portion connected to the base portion and extending in a first direction away from the outer circumferential surface;
A heat dissipation structure, wherein when viewed in a cross-sectional view from a second direction in which a cylindrical axis of the cylindrical body extends, the width of the base is greater than the width of the main body.
The heat dissipation structure of claim 1, including a weld bead region between the outer circumferential surface and the base.
The heat dissipation structure according to claim 1, wherein the outer peripheral surface and the base are joined by solid-state diffusion bonding.
The heat dissipation structure of claim 1, wherein the base and the main body are formed from a single plate-like member.
The heat dissipation structure of claim 1, wherein each of the fins has an L-shape in the cross-sectional view.
The heat dissipation structure according to claim 5, wherein the end of the base includes a notch.
The heat dissipation structure of claim 1, wherein each of the fins has a U-shape in the cross-sectional view.
the plurality of fins includes a first fin and a second fin;
The heat dissipation structure of claim 1 , wherein the first fin and the second fin are disposed in the second direction.
The heat dissipation structure of claim 8, wherein the first fins and the second fins are arranged in a staggered pattern in the second direction.
The heat dissipation structure of claim 1, wherein the base includes a smooth surface that is joined to the outer peripheral surface.
The heat dissipation structure according to claim 1, wherein the joint surface of the base that is joined to the outer peripheral surface is curved to match the shape of the outer peripheral surface.
The heat dissipation structure of claim 1, wherein each of the fins has a T-shape in the cross-sectional view.
The heat dissipation structure according to claim 1, wherein a first fin and a second fin that are adjacent to each other among the plurality of fins are arranged such that an end of the base of the first fin faces an end of the base of the second fin.
A cylindrical body including a curved outer circumferential surface;
a plurality of fins disposed on the outer circumferential surface;
Each of the plurality of fins is
A base portion joined to the outer circumferential surface;
a plurality of body portions connected to the one base portion and extending in a first direction away from the outer circumferential surface;
A heat dissipation structure, wherein when viewed in a cross-sectional view from a second direction in which the cylindrical axis of the cylindrical body extends, the width of the one base portion is greater than the width of one of the main body portions included in the multiple main body portions.
The heat dissipation structure of claim 14, wherein each of the fins has an L-shape in the cross-sectional view.
In the cross-sectional view, a width of the one base portion is greater than twice the width of one of the main body portions included in the plurality of main body portions;
The heat dissipation structure of claim 14 , wherein each of the plurality of fins has a U-shape in the cross-sectional view.
The heat dissipation structure according to claim 16, wherein the plurality of main body portions are arranged in a staggered pattern in the second direction.
The heat dissipation structure of claim 1, wherein at least one of the surface, end, and side of the main body includes at least one shaped portion selected from a groove, a recess, and a protrusion.
The heat dissipation structure of claim 1, wherein the material of the fins is the same as the material of the cylindrical body.
Fixing the position of the cylindrical body including the curved outer circumferential surface;
a base of a fin including a base and a body portion connected to the base, the base being disposed on the outer circumferential surface;
joining the base to the outer periphery using welding;
A method for manufacturing a heat dissipation structure, wherein, when viewed in a cross-sectional view from a direction in which a cylindrical axis of the cylindrical body extends, the width of the base is larger than the width of the main body.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the welding is one of laser welding, arc welding, and electron beam welding.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the welding is performed by irradiating at least the base with a laser beam, an arc, or an electron beam.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the welding is performed by irradiating the inner surface of the cylindrical body with a laser beam, an arc, or an electron beam.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the welding is performed by irradiating at least one of the upper and lower surfaces of the cylindrical body with a laser beam, an arc, or an electron beam.
The method for manufacturing a heat dissipation structure according to claim 20, further comprising processing the fins including the base and the main body from a single plate-like member.
The method for manufacturing a heat dissipation structure according to claim 20, further comprising processing the joining surface of the base that is joined to the outer peripheral surface into a curved shape that matches the shape of the outer peripheral surface.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the fin has an L-shape in the cross-sectional view.
The method for manufacturing a heat dissipation structure according to claim 20, wherein the fin has a T-shape in the cross-sectional view.
The method for manufacturing a heat dissipation structure according to claim 20, wherein at least one of the surface, end, and side of the main body includes at least one shaped portion selected from a groove, a recess, and a protrusion.
The method for manufacturing a heat dissipation structure according to claim 20 , wherein the material of the fins is the same as the material of the cylindrical body.