JP6891686B2 - Manufacturing method of sheet brazing material and heat exchanger - Google Patents

Description

The present invention relates to a method for manufacturing a sheet-shaped brazing material and a heat exchanger.

In general, heat exchangers are widely used in devices that require the use of heat energy and heat removal. Among them, a plate type heat exchanger is known as a typical high-performance heat exchanger (see, for example, Patent Document 1). In such a plate-type heat exchanger, a plurality of metal plates partially formed to be thin by press working or half-etching are stacked, and the heat exchange fluids flow in opposition or in parallel between the metal plates. It is designed to form a road.

Further, in the plate type heat exchanger, in order to improve the heat transfer efficiency between two heat exchange fluids having different temperatures, a plurality of heat transfer fins are provided in the flow path through which the heat exchange fluid passes to increase the heat transfer area. ..

Japanese Unexamined Patent Publication No. 2006-170549 Japanese Patent No. 3893110

For example, in Patent Document 1, when a heat exchanger is manufactured, a metal plate having a microchannel is manufactured by etching, and the metal plates are joined by a diffusion joining method. However, when the diffusion bonding method is used, if there is a slight difference in the flatness of the metal plates or if the number of laminated metal plates increases, bonding defects are likely to occur and the production efficiency is lowered. There's a problem. Further, in Patent Document 2, the plate and the fin are joined by a brazing joining method.

However, conventionally, the etched metal plate tends to have a larger warp than the metal plate before the etching process. For this reason, when a pair of etched metal plates are joined by, for example, a brazing joining method, if the surfaces on which the flow paths are processed are arranged so as to face each other, a space is created between the pair of metal plates. There is a problem that it is easy to occur.

The present invention has been made in consideration of such a point, and is a method for manufacturing a sheet-shaped brazing material and a heat exchanger capable of reliably joining etched metal plates to each other by a brazing joining method. The purpose is to provide.

The present invention is a sheet-shaped brazing material for joining a pair of metal plates for heat exchangers to each other, and includes a longitudinal direction and a width direction perpendicular to the longitudinal direction, and the thickness of the central portion in the width direction is increased. It is a sheet-like brazing material thicker than the thickness of the end portion in the width direction.

The present invention is a sheet-like brazing material in which the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 1% or more and 20% or less of the thickness of the central portion in the width direction.

The present invention is a sheet-like brazing material in which the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 2 μm or more and 50 μm or less.

The present invention is a method for manufacturing a heat exchanger, which comprises a step of preparing at least a pair of heat exchanger metal plates and a step of joining the pair of heat exchanger metal plates to each other via a sheet-shaped brazing material. The sheet-shaped brazing material includes a longitudinal direction and a width direction perpendicular to the longitudinal direction, and the thickness of the central portion in the width direction is thicker than the thickness of the end portion in the width direction. The method.

The present invention is a method for manufacturing a heat exchanger in which the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 1% or more and 20% or less of the thickness of the central portion in the width direction.

The present invention is a method for manufacturing a heat exchanger in which the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 2 μm or more and 50 μm or less.

According to the present invention, the etched metal plates can be reliably joined by a brazing joining method.

FIG. 1 is an exploded perspective view showing a heat exchanger according to an embodiment of the present invention. 2 (a) and 2 (c) are plan views showing metal plates, respectively, and FIG. 2 (b) is a plan view showing a sheet-shaped brazing material according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a sheet-shaped brazing material according to an embodiment of the present invention (cross-sectional view taken along line III-III of FIG. 2A). FIG. 4 is a partially enlarged plan view showing a sheet-shaped brazing material (enlarged view of part IV of FIG. 2B). FIG. 5 is a cross-sectional view showing a pair of metal plates joined to each other (a view corresponding to the VV line cross section of FIG. 4). FIG. 6 is a schematic view showing a process of manufacturing a metal plate for brazing material. FIG. 7 is a diagram showing a state in which molten metal is supplied onto a casting roll while a metal plate for brazing material is produced.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. In each of the following figures, the same parts are designated by the same reference numerals, and some detailed description may be omitted.

Configuration of Heat Exchanger First, the outline of the heat exchanger according to the present embodiment will be described with reference to FIG. FIG. 1 is an exploded perspective view showing a heat exchanger according to the present embodiment.

As shown in FIG. 1, the heat exchanger (plate type heat exchanger) 10 according to the present embodiment includes one fixing plate 11 and the other fixing plate 12 provided apart from one fixing plate 11. , A plurality of (four in FIG. 1) metal plates (metal thin plate-shaped plates) for heat exchangers 20A to 20D arranged in a laminated manner between one fixing plate 11 and the other fixing plate 12 are provided. There is.

Of these, the plurality of metal plates 20A to 20D are composed of metal plates 20A and 20B for the _first fluid F 1 and metal plates 20C and 20D for the _{second fluid F 2.}

A sheet-shaped brazing material (patterned brazing material) 30A on which a predetermined pattern is formed is arranged between the pair of metal plates 20A and 20B for heat exchangers (hereinafter, also referred to as metal plates 20A and 20B). A pair of metal plates 20A and 20B are joined to each other by the sheet-shaped brazing material 30A. Similarly, a sheet-shaped brazing material (patterned brazing material) 30B having a predetermined pattern formed is arranged between the pair of metal plates 20C and 20D for heat exchangers (hereinafter, also referred to as metal plates 20C and 20D). ing. A pair of metal plates 20C and 20D are joined to each other by the sheet-shaped brazing material 30B.

The sheet-shaped brazing materials 30A and 30B each have a brazing material outer peripheral region 31, a penetrating region 32 formed inside the brazing material outer peripheral region 31, and a plurality of covering regions 35 and bridges (connecting) arranged in the penetrating region 32. Part) 36 and. The configurations of the sheet-shaped brazing materials 30A and 30B will be described later.

In FIG. 1, the sheet-shaped brazing materials 30A and 30B show the state before joining, and the covering region 35 and the bridge 36 are arranged in the through region 32. On the other hand, in the completed heat exchanger 10, the covering region 35 and the bridge 36 are melted except for the portion joined to the heat transfer fin 25.

A sheet-shaped brazing material (non-patterned brazing material) 30C having no pattern is arranged between the fixing plate 11 and the metal plate 20A. One fixing plate 11 and the metal plate 20A are joined to each other by the sheet-shaped brazing material 30C. Further, a sheet-shaped brazing material (non-patterned brazing material) 30D having no pattern formed is arranged between the pair of metal plates 20B and 20C. A pair of metal plates 20B and 20C are joined to each other by the sheet-shaped brazing material 30D. Further, a sheet-shaped brazing material (non-patterned brazing material) 30E having no pattern formed is arranged between the other fixing plate 12 and the metal plate 20D. The other fixing plate 12 and the metal plate 20D are joined to each other by the sheet-shaped brazing material 30E.

Unlike the sheet-shaped brazing materials 30A and 30B, the sheet-shaped brazing materials 30C to 30E do not have the brazing material outer peripheral region 31, the penetration region 32, the covering region 35, and the bridge 36. That is, the sheet-shaped brazing materials 30C to 30E are spread all over without having an opening or the like, except that the inlet side openings 33A and 33B and the outlet side openings 34A and 34B through which the fluid passes are formed through. .. Further, the sheet-shaped brazing materials 30C to 30E have substantially the same planar shape as each other.

In this way, the metal plates 20A to 20D, or the metal plates 20A to 20D and the fixing plates 11 and 12, are joined to each other by using the sheet-shaped brazing materials 30A to 30E. As a result, even if there is a slight difference in the flatness of the metal plates 20A to 20D or the number of laminated metal plates 20A to 20D increases, the metal plates 20A to 20D do not have poor bonding. , There is no risk of production efficiency decreasing.

One fixing plate 11 and the other fixing plate 12 each have a substantially rectangular shape in a plane. The inflow pipes 13A and 13B and the outflow pipes 14A and 14B are connected to one of the fixing plates 11. On the other hand, the other fixing plate 12 has a flat shape without forming an opening or the like.

Inlet pipe 13A and outlet pipe 14A is one in which the first fluid _{F 1,} each of which inflow and outflow. First fluid F ₁ is the compressor or pump (not shown), flows from the inlet pipe 13A to the heat exchanger 10, the metal plate 20A, while circulating within 20B performs heat exchange, so as to flow out from the outflow pipe 14A It has become. Further, the inlet pipe 13B and outlet pipe 14B is one in which the second fluid _{F 2,} each of which inflow and outflow. The second fluid F ₂ flows into the heat exchanger 10 from the inflow pipe 13B by a compressor or a pump (not shown), exchanges heat while circulating in the metal plates 20C and 20D, and flows out from the outflow pipe 14B. It has become.

The temperatures of the first fluid F ₁ and the second fluid F ₂ are different from each other at least when they flow into the inflow pipes 13A and 13B. The first fluid F ₁ and the second fluid F ₂ may be a gas such as carbon dioxide or air, or a liquid such as water. The first fluid F ₁ and the second fluid F ₂ may use the same type of fluid or different types of fluids from each other.

Thus, in the heat exchanger 10, the metal plate 20A, the first fluid _{F 1} passing between 20B, metal plates 20C, with the second fluid _{F 2} passing between 20D, Heat exchange is being carried out. Although the number of metal plates 20A to 20D is shown in FIG. 1 for convenience, the number is not limited to this, and may be, for example, about 20 or more and 200 or less.

Such a heat exchanger 10 can be used, for example, in a heat pump unit of a water heater, air conditioning equipment, an in-vehicle EGR (Exhaust Gas Recirculation) cooler, a chemical plant, or the like.

Structure of Metal Plate Next, with reference to FIGS. 2 (a) and 2 (c), the structure of the metal plate to be joined using the sheet-shaped brazing material according to the present embodiment will be described. In the following, the configurations of the pair of metal plates 20A and 20B for the _first fluid F1 will be described, but the configurations of the pair of metal plates 20C and 20D for the _{second fluid F2 are substantially the same.} Is.

As shown in FIGS. 2A and 2C, the pair of metal plates 20A and 20B each have a substantially rectangular shape in a plane and has a longitudinal direction and a width direction. In FIGS. 2A and 2C, the longitudinal direction is parallel to the Y direction, and the width direction is parallel to the X direction orthogonal to the Y direction.

The metal plates 20A and 20B each have an outer peripheral region 21 and a thin-walled region (half-etched region) 22 formed inside the outer peripheral region 21. Of these, the outer peripheral region 21 is formed in an annular shape along the entire outer circumference of each of the metal plates 20A and 20B. The outer peripheral region 21 is not half-etched and has the same thickness as the entire thickness of the metal plates 20A and 20B.

Further, the thin-walled region 22 is thinner than the outer peripheral region 21, and is formed only on one surface side of the metal plates 20A and 20B. In this case, the thin-walled region 22 is formed by, for example, half-etching from the one side. In addition, "half etching" means etching the material to be etched halfway in the thickness direction thereof. The depth of the thin-walled region 22 may be, for example, about 40% or more and 60% or less of the thickness of the outer peripheral region 21.

In the thin-walled region 22, an inlet side opening 23A and an outlet side opening 24A are formed in the vicinity of the pair of corners of the metal plates 20A and 20B, respectively. The inlet-side opening 23A, the outlet side opening 24A, together with the first fluid _{F 1} passes, and communicates with the thin region 22.

Further, in the outer peripheral region 21, an inlet side opening 23B and an outlet side opening 24B are formed in the vicinity of the other pair of corners of the metal plates 20A and 20B, respectively. The inlet-side opening 23B, the outlet opening 24B, together with the second fluid _{F 2} passes through the metal plate 20A, and so does not communicate with the thin region 22 of the 20B, on the other hand, the metal plate 20C, 20D of It communicates with the thin-walled region 22.

These inlet side openings 23A and 23B and outlet side openings 24A and 24B are formed so as to penetrate the metal plates 20A and 20B. The inlet side openings 23A and 23B and the outlet side openings 24A and 24B may be formed by etching from both sides at the same time as the thin area 22 when the thin area 22 is formed by half etching from one side.

A plurality of heat transfer fins 25 are provided in the thin-walled region 22 so as to project in the Z direction (thickness directions of the metal plates 20A and 20B), respectively. The thickness of the portion where each heat transfer fin 25 is provided is the same as the thickness of the outer peripheral region 21. On the other hand, each heat transfer fin 25 is arranged so as to be separated from the outer peripheral region 21 and the other heat transfer fins 25 in the plane direction (X direction and Y direction), respectively. Therefore, each heat transfer fin 25 is independently arranged in an island shape, and a flow path 26 for passing _{the first fluid F 1 is formed around each heat transfer fin 25.} Although only some of the heat transfer fins 25 are shown in FIGS. 1 and 2 (a) and 2 (c) for convenience, the heat transfer fins 25 are actually arranged over substantially the entire area of the thin-walled region 22. Has been done.

Each heat transfer fin 25 has a substantially S-shaped plane. The heat transfer fins 25 are arranged in large numbers at regular intervals along the first fluid F ₁ of the main flow direction D (Y-direction). Further, the heat transfer fins 25 are disposed in parallel to each other at a predetermined interval in a direction (X direction) perpendicular to the first fluid F ₁ of the main flow direction D (Y-direction). Both ends of the heat transfer fin 25 in the longitudinal direction are formed in a streamlined shape so as not to cause turbulence such as a vortex or a swirling flow, and are configured to minimize fluid resistance. The shape of each heat transfer fin 25 may be a flat circular shape, a flat oval shape, or a flat polygonal shape.

In the present embodiment, as shown in FIGS. 2A and 2C, a longitudinal edge portion 27 and a lateral edge portion 28 are formed on the thin-walled region 22 side of the outer peripheral region 21. Of these, the longitudinal edge portion 27 extends linearly along the mainstream direction D (Y direction) of _{the second fluid F 2.} The longitudinal edge portion 27 may have a wavy shape or a zigzag shape along the shape of the heat transfer fin 25. Further, the lateral edge portion 28 is formed so as to be bent along a direction (X direction) orthogonal to the mainstream direction D in the outer peripheral region 21.

Configuration of Sheet-Shaped Blazing Material Next, the configuration of the sheet-shaped brazing material according to the present embodiment will be described with reference to FIGS. 2 (b), 3 and 4. In the following, the configuration of the sheet-shaped brazing material 30A for joining the metal plates 20A and 20B will be described, but the configuration of the sheet-shaped brazing material 30B for joining the metal plates 20C and 20D is substantially the same.

FIG. 2B shows the sheet-shaped brazing material 30A in a state before being joined. The sheet-shaped brazing material 30A has a substantially rectangular shape in a plane, and has a longitudinal direction and a width direction. In FIG. 2B, the longitudinal direction is parallel to the Y direction, and the width direction is parallel to the X direction orthogonal to the Y direction. Further, the sheet-shaped brazing material 30A has a brazing material outer peripheral region 31 and a penetration region (etching region) 32 formed inside the brazing material outer peripheral region 31. Of these, the brazing material outer peripheral region 31 has substantially the same shape as the outer peripheral region 21 of the metal plates 20A and 20B, and is formed in an annular shape along the entire outer peripheral region of the sheet-shaped brazing material 30A. The brazing material outer peripheral region 31 is a region that has not been etched.

The penetration region 32 is formed so as to penetrate the sheet-shaped brazing material 30A in the thickness direction. In this case, the penetration region 32 is formed by, for example, etching the sheet-shaped brazing material 30A from both sides.

In the brazing material outer peripheral region 31, an inlet side opening 33B and an outlet side opening 34B are formed in the vicinity of the pair of corners of the sheet-shaped brazing material 30A, respectively. The inlet-side opening 33B, the outlet opening 34B, together with the second fluid _{F 2} passes, the through region 32 of the sheet-like brazing material 30A and so as not to communicate, while metal plate 20C, 20D of It communicates with the thin-walled region 22. The inlet side opening 33B and the outlet side opening 34B are formed so as to penetrate the sheet-shaped brazing material 30A. The inlet side opening 33B and the outlet side opening 34B may be formed by etching from both sides at the same time as the penetration region 32 when the penetration region 32 is formed by etching.

A plurality of covering regions 35 are arranged inside the penetration region 32. Each covering region 35 is arranged at a position covering the entire plane of the corresponding heat transfer fin 25. The thickness of each covering region 35 is the same as the thickness of the brazing material outer peripheral region 31. Further, each covering region 35 is arranged so as to be separated from the brazing material outer peripheral region 31 and the other covering regions 35 in the plane direction (X direction and Y direction), respectively. The covering region 35 is a part of a region that remains without being etched when the penetration region 32 is formed by etching from both sides.

Further, each covering region 35 is held in the brazing material outer peripheral region 31 via the bridge 36, respectively. That is, at least one bridge 36 is connected to each covering region 35, and this bridge 36 is connected to the other covering region 35 and / or the brazing material outer peripheral region 31. As a result, all the covering regions 35 are held in the brazing material outer peripheral region 31 via the bridge 36 so as not to fall off from the brazing material outer peripheral region 31. The bridge 36 is composed of a part of a region that remains without being etched when the penetration region 32 is formed by etching from both sides. Although only a part of the covering region 35 and the bridge 36 are shown in FIGS. 1 and 2 (b) for convenience, in reality, the covering region 35 and the bridge 36 cover substantially the entire area of the penetration region 32. Have been placed.

FIG. 3 is a cross-sectional view (cross-sectional view taken along line III-III of FIG. 2B) along the width direction (X direction) of the sheet-shaped brazing material 30A, in which the bridge 36 is the entire width direction of the sheet-shaped brazing material 30A. It is sectional drawing in the part extending over. In FIG. 3, the sheet-shaped brazing material 30A is drawn exaggerated in the thickness direction (Z direction).

As shown in FIG. 3, the sheet-shaped brazing material 30A has a pair of widthwise end portions 30b and 30b and a widthwise central portion 30a located between the pair of widthwise end portions 30b and 30b. .. In this embodiment, the widthwise central portion 30a of the sheet-like brazing material 30A is raised greater than the width direction end portion 30b, the thickness t _a of the widthwise central portion 30a, the thickness t of the widthwise end portion 30b _It is thicker than b. In this case, the sheet-shaped brazing material 30A is the thickest at the central portion 30a in the width direction and the thinnest at the end portion 30b in the width direction. Further, the sheet-shaped brazing material 30A is gently inclined from the central portion 30a in the width direction toward the end portion 30b in the width direction on both the front surface and the back surface. The central portion 30a in the width direction is thicker than the end portion 30b in the width direction over the entire area of the sheet-shaped brazing material 30A in the longitudinal direction (Y direction).

In this embodiment, the thickness _{t a} of the widthwise central portion 30a may be 20μm or more 500μm or less. The difference between the thickness _{t b} of the thickness _{t a} and the widthwise end portion 30b of the widthwise central portion 30a of the sheet-like brazing material 30A _(t a -t _b), the first thickness _{t a} of the widthwise central portion 30a % Or more and 20% or less. Moreover, the difference between the thickness _{t b} of the thickness _{t a} and the widthwise end portion 30b of the widthwise central portion 30a _(t a -t _b) has a 2μm or 50μm or less. Absorb the difference between the thickness t _b of the thickness t _a and the widthwise end portion 30b of the widthwise central portion 30a is in the above range, the metal plate 20A by the sheet-like brazing material 30A, a warp in the widthwise central portion of the 20B However, the metal plates 20A and 20B can be easily joined to each other.

The thickest portion of the sheet-shaped brazing material 30A is not limited to the central portion 30a in the width direction, and may be deviated from the central portion 30a in the width direction in the width direction. Further, the thickness of the sheet-shaped brazing material 30A does not necessarily have to decrease monotonically from the central portion 30a in the width direction toward the end portion 30b in the width direction. For example, the sheet-shaped brazing material 30A may increase or decrease in thickness from the central portion 30a in the width direction to the end portion 30b in the width direction, and may decrease in thickness along the width direction as a whole.

Although not shown, the same applies to the other sheet-like brazing material 30b to 30e, it is thicker than the thickness _{t b} thickness _{t a} of the widthwise end portion 30b of the widthwise central portion 30a.

Next, the configuration of the covering region 35 and the bridge 36 will be described with reference to FIG. FIG. 4 is an enlarged view of part IV of FIG. 2B, and the positions of the corresponding heat transfer fins 25 are shown by virtual lines (dashed-dotted lines).

As shown in FIG. 4, each covering region 35 has a substantially S-shaped plane along the heat transfer fin 25. In FIG. 4, the region S indicates the outer peripheral edge of the covering region 35. The covering region 35 covers the entire plane of the heat transfer fin 25. In this case, each covering region 35 is slightly larger than the shape of the corresponding heat transfer fin 25, and may be formed widely on the side, for example, about 10 μm or more and 200 μm or less. As a result, even if a slight positional deviation occurs between the covering region 35 and the heat transfer fins 25 at the time of joining, the heat transfer fins 25 can be reliably joined to each other. When the shape of each heat transfer fin 25 is a plane circle shape, a plane oval shape, or a plane polygon shape, the shape of each covering region 35 is a plane circle shape according to the shape of each heat transfer fin 25. It may be a plane oval shape or a plane polygon shape.

Each coating region 35 is arranged a number at regular intervals along the first fluid F ₁ of the main flow direction D (Y-direction). Further, the coating region 35 is arranged parallel to at regular intervals in a direction (X direction) perpendicular to the first fluid F ₁ of the main flow direction D (Y-direction).

The bridge 36 has a substantially linear shape in a plane. The bridge 36 connects the end portion of each covering region 35 and the intermediate portion of the covering region 35 adjacent to the covering region 35 in the X direction to each other. In this embodiment, each bridge 36 extends parallel to the X direction. In this case, since the area of the sheet-shaped brazing material 30 can be secured widely around the end of the heat transfer fin 25, the ends of the heat transfer fins 25 of the sheet-shaped brazing materials 30A and 30B are surely joined to each other. can do.

Next, the metal plates 20A and 20B joined by the sheet-shaped brazing material 30A will be described with reference to FIG. FIG. 5 shows a state in which the metal plates 20A and 20B have been joined to each other, and corresponds to the VV line cross section of FIG.

As shown in FIG. 5, the metal plates 20A and 20B are arranged so that the surfaces on which the thin-walled region 22 is formed face each other. Further, the thin region 22 of the pair of metal plates 20A and 20B and the plurality of heat transfer fins 25 are formed so as to be mirror-symmetrical to each other. Therefore, when the metal plates 20A and 20B are joined to each other, the thin-walled regions 22 are joined so that the corresponding heat transfer fins 25 are joined to each other. Further, a sheet-shaped brazing material 30A is interposed between the metal plates 20A and 20B, and the metal plates 20A and 20B are joined to each other by the sheet-shaped brazing material 30A. The metal plate 20A, a thin region 22 of the 20B, the first fluid _{F 1} flows flow path 26 by the through region 32 of the sheet-like brazing material 30A is formed.

In the state where the joining is completed in this way, the sheet-shaped brazing material 30A is melted and removed except for the outer peripheral region 21 of the metal plates 20A and 20B and the region corresponding to the heat transfer fin 25. That is, the sheet-shaped brazing material 30A has a brazing material outer peripheral region 31 and a plurality of fin joining regions 35a corresponding to the shape of each heat transfer fin 25 while being arranged in the through region 32. The fin bonding region 35a is composed of a portion of the covering region 35 bonded to the heat transfer fin 25.

In this case, the flow path 26 has a region not covered by the material constituting the sheet-shaped brazing material 30A. A small amount of residue 38 of the sheet-shaped brazing material 30A may remain in the flow path 26. The residue 38 is formed by melting a portion of the covering region 35 that is not bonded to the heat transfer fin 25 or the bridge 36. It is preferable that the materials of the metal plates 20A and 20B are exposed without the residue 38 covering, for example, 40% or more and 90% or less of the area of the flow path 26 when viewed from the plane direction. The amount of the sheet-like brazing material 30A residues 38 to total flow path 26 is negligible and, or occluded flow path 26 by the residue 38, there is no risk of affecting the first flow of fluid F ₁ is or cause.

By the way, since the metal plates 20A and 20B are half-etched, they tend to warp so that the surface side on which the thin-walled region 22 is formed becomes concave. Therefore, when the opposing metal plates 20A and 20B are opposed to each other, a gap tends to occur in the central portion in the width direction thereof. On the other hand, in the present embodiment, the central portion 30a in the width direction of the sheet-shaped brazing material 30A is thicker than the end portion 30b in the width direction, so that more brazing material is placed in the gap between the metal plates 20A and 20B. It becomes possible to arrange. Therefore, when the metal plates 20A and 20B are joined by the sheet-shaped brazing material 30A, the central portion 30a in the width direction of the metal plates 20A and 20B can be joined more firmly and reliably. After being joined by the sheet-shaped brazing material 30A, the warpage of the metal plates 20A and 20B is almost eliminated, and the metal plates 20A and 20B have a horizontal shape along the width direction.

The metal plates 20A and 20B are preferably metals having good thermal conductivity, and various choices such as stainless steel, iron, copper, copper alloy, aluminum, aluminum alloy, and titanium can be selected. Further, the thicknesses of the metal plates 20A and 20B may be, for example, 0.1 mm or more and 2.0 mm or less, respectively. This also applies to the metal plates 20C and 20D described above.

The sheet-shaped brazing material 30A can be variously selected, for example, nickel, silver, copper, or an alloy containing any of these. This also applies to the sheet-shaped brazing materials 30B to 30E described above.

In the present embodiment, the height h (distance in the Z direction) of the flow path 26 (see FIG. 5) is the depth of the thin region 22 of the metal plates 20A and 20B and the thickness of the sheet-shaped brazing material 30A after joining. Is defined by the sum of. Specifically, the height h of the flow path 26 is preferably, for example, 0.1 mm or more and 1.0 mm or less. By suppressing the height h of the flow path 26 in this way, the heat exchanger 10 can be made compact and the efficiency of heat exchange can be improved.

Method for Manufacturing Heat Exchanger Next, the method for manufacturing the above-mentioned heat exchanger will be described.

First, the above-mentioned metal plates 20A to 20D are produced by etching, respectively. In this case, a flat plate-shaped metal plate for a plate corresponding to each of the metal plates 20A to 20D is prepared, and the thin-walled region 22 is formed by half-etching each of the metal plates for the plate. Further, when forming the thin-walled region 22, the metal plate for the plate is etched from both sides to form the inlet side openings 23A and 23B and the outlet side openings 24A and 24B, respectively. At this time, the outer peripheral region 21 and the region corresponding to the heat transfer fin 25 retain the same thickness as the metal plate for the plate without being etched. As described above, in the metal plates 20A to 20D produced by etching, the surface on the thin-walled region 22 side, which is the half-etched surface, tends to warp in a concave shape.

Further, flat plate-shaped metal plates for brazing materials corresponding to the sheet-shaped brazing materials 30A and 30B are prepared, and the metal plates for brazing materials are etched to produce the above-mentioned sheet-shaped brazing materials 30A and 30B. ..

In this case, first, as shown in FIG. 6, the molten metal 30Q for the brazing material is supplied from the melting furnace 91 onto the rotating casting roll 92. Next, the metal 30Q is cooled and solidified on the casting roll 92 to form a sheet, which is wound around the roll 93 to obtain a flat metal plate 30P for brazing material.

As shown in FIG. 7, when the metal 30Q is supplied from the melting furnace 91 onto the casting roll 92, a mesh-shaped filter 94 is provided above the casting roll 92, and the metal 30Q is cast by passing through the filter 94. Pour into roll 92. In this case, the filter 94 supplies a large amount of metal 30Q to the central portion in the width direction of the casting roll 92, so that the thickness of the central portion in the width direction of the metal plate 30P for brazing material is made thicker than the thickness of the end portion in the width direction. Can be done.

Next, the through regions 32 are formed by etching the brazing metal plate 30P thus obtained from both sides. Further, at the same time as forming the penetration region 32, the inlet side openings 33A and 33B and the outlet side openings 34A and 34B are also formed. On the other hand, the brazing material outer peripheral region 31, the covering region 35, and the bridge 36 are formed at the same time, and these regions retain the thickness of the brazing material metal plate 30P before processing without being etched. In this way, sheet-shaped brazing materials 30A and 30B having a thickness of the central portion 30a in the width direction thicker than that of the end portion 30b in the width direction can be obtained.

Similarly, the above-mentioned sheet-shaped brazing materials 30C to 30E are produced by etching. Only the openings 33A, 33B, 34A, and 34B through which the fluid passes are formed through the sheet-shaped brazing materials 30C to 30E by etching.

Subsequently, as shown in FIG. 1, the metal plates 20A to 20D and the sheet-shaped brazing materials 30A to 30E are sandwiched between the one fixing plate 11 and the other fixing plate 12. In this case, in order from one fixing plate 11 side, sheet-shaped brazing material 30C, metal plate 20A, sheet-shaped brazing material 30A, metal plate 20B, sheet-shaped brazing material 30D, metal plate 20C, sheet-shaped brazing material 30B, metal plate. 20D, the sheet-shaped brazing material 30E, and the other fixing plate 12 are arranged.

The fixing plate 11, the metal plates 20A to 20D, the sheet-shaped brazing materials 30A to 30E, and the other fixing plate 12 are each formed with positioning holes (not shown) at predetermined positions in advance. Using this positioning hole, one fixing plate 11, metal plates 20A to 20D, sheet-shaped brazing materials 30A to 30E, and the other fixing plate 12 are positioned, and these are aligned and fixed by a resistance welding method. You may.

Next, one of the fixing plates 11 thus positioned, the metal plates 20A to 20D, the sheet-shaped brazing materials 30A to 30E, and the other fixing plate 12 are put into a brazing furnace (not shown). In this brazing furnace, the sheet-shaped brazing materials 30A to 30E are heated and melted at a temperature of about 900 ° C. or higher and 1200 ° C. or lower. As a result, one fixing plate 11, the metal plates 20A to 20D, and the other fixing plate 12 are joined by the sheet-shaped brazing materials 30A to 30E, respectively.

At this time, the metal plates 20A and 20B are joined to each other via the sheet-shaped brazing material 30A. At this time, the outer peripheral regions 31 of the brazing material 30A of the sheet-shaped brazing material 30A bring the outer peripheral regions 21 of the metal plates 20A and 20B into close contact with each other. Further, the heat transfer fins 25 of the metal plates 20A and 20B are reliably brought into close contact with each other by the covering region 35 (fin joining region 35a) of the sheet-shaped brazing material 30A. On the other hand, a space (penetration region 32) is formed around the covering region 35. Therefore, there is no possibility that the flow path 26 is blocked by the brazing material existing around the covering region 35. Of the sheet-shaped brazing material 30A, a part of the covering region 35 (a portion located outside the heat transfer fin 25) and the bridge 36 are melted, whereby a small amount of residue 38 of the sheet-shaped brazing material 30A flows through the flow path. Remains at 26. However, as described above, the amount of residues 38 to total flow path 26 is negligible, or the flow path 26 is closed by the residue 38, a possibility is low that affect the first flow of fluid F ₁ is or cause .. The metal plates 20C and 20D are also joined to each other via the sheet-shaped brazing material 30B in the same manner.

As described above, the metal plates 20A to 20D may be warped, and a gap may be formed between the central portions of the metal plates 20A to 20D in the width direction. On the other hand, in the present embodiment, the width direction central portion 30a of the sheet-shaped brazing materials 30A and 30B is thicker than the width direction end portion 30b. Therefore, more brazing materials can be arranged in the gaps between the metal plates 20A to 20D, and when the metal plates 20A to 20D are joined by the sheet-shaped brazing materials 30A and 30B, the width of the metal plates 20A to 20D is wide. The central portion 30a in the direction can be joined more reliably. As a result, the warp of the metal plates 20A to 20D after joining is almost eliminated, and the metal plates 20A to 20D can be made substantially horizontal.

In this way, one fixing plate 11, the metal plates 20A to 20D, and the other fixing plate 12 are tightly joined to obtain the heat exchanger 10 according to the present embodiment.

Action of the present embodiment Next, the action of the heat exchanger having such a configuration will be described.

First, in the heat exchanger 10 shown in FIG. 1, the first fluid F ₁ is introduced into the inflow pipe 13A, and the second fluid F ₂ is introduced into the inflow pipe 13B. In this case, the _{temperature of the first fluid F 1 and} the temperature of the second fluid F ₂ are different from each other.

Next, the first fluid F ₁ passes through the flow path 26 formed in the thin-walled region 22 between the metal plates 20A and 20B, and flows out from the outflow pipe 14A of the heat exchanger 10. Similarly, the second fluid F ₂ passes through the flow path 26 formed in the thin-walled region 22 between the metal plates 20C and 20D, and flows out from the outflow pipe 14B of the heat exchanger 10. At the time of flowing out from the outflow pipe 14A, 14B, one of the temperature of the first fluid F ₁ and the second fluid F ₂ is higher than at the inflow and the other temperature is lowered than at the inflow. In this case, since the metal plate 20B and the metal plate 20C are bonded to each other, the metal plate 20B, through 20C, the heat exchange efficiency between the first fluid F ₁ and the second fluid F ₂ It is done as a target.

As described above, according to the present embodiment, the width direction central portion 30a of the sheet-shaped brazing material 30A is thicker than the width direction end portion 30b. As a result, more brazing material can be arranged in the gap between the metal plates 20A and 20B, and the metal plates 20A and 20B can be joined more firmly and reliably.

Further, according to the present embodiment, since the flow paths 26 of the metal plates 20A to 20D are manufactured by etching, the heat exchanger 10 is compact and highly efficient as compared with the case where the flow paths are manufactured by pressing. Can be. This makes it possible to improve energy efficiency, including reducing the amount of refrigerant.

It is also possible to appropriately combine the plurality of components disclosed in the above-described embodiment as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiment.

10 Heat exchanger 11 One fixing plate 12 The other fixing plate 20A to 20D Metal plate 21 Outer peripheral area 22 Thin-walled area 25 Heat transfer fin 26 Flow path 27 Longitudinal edge 28 Lateral edge 30A to 30E Sheet-like brazing material 30a Width direction center part 30b Width direction end part 31 Row material outer circumference area 32 Penetration area 35 Covering area 35a Fin joint area 36 Bridge

Claims (6)

A sheet-like brazing material for joining a pair of metal plates for heat exchangers to each other.
Longitudinal and
With a width direction perpendicular to the longitudinal direction,
A sheet-like brazing material in which the thickness of the central portion in the width direction is thicker than the thickness of the end portion in the width direction. The sheet-shaped brazing material according to claim 1, wherein the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 1% or more and 20% or less of the thickness of the central portion in the width direction. The sheet-shaped brazing material according to claim 1 or 2, wherein the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 2 μm or more and 50 μm or less. It is a method of manufacturing a heat exchanger.
The process of preparing at least a pair of metal plates for heat exchangers,
A step of joining the pair of metal plates for heat exchangers to each other via a sheet-shaped brazing material is provided.
The sheet-shaped brazing material is
Longitudinal and
With a width direction perpendicular to the longitudinal direction,
A method for manufacturing a heat exchanger in which the thickness of the central portion in the width direction is thicker than the thickness of the end portion in the width direction. The method for manufacturing a heat exchanger according to claim 4, wherein the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 1% or more and 20% or less of the thickness of the central portion in the width direction. The method for manufacturing a heat exchanger according to claim 4 or 5, wherein the difference between the thickness of the central portion in the width direction and the thickness of the end portion in the width direction is 2 μm or more and 50 μm or less.

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