JP2018158371A - Heat exchanger and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable fluxless brazing under low oxygen concentration environment in manufacture of a heat exchanger made of an aluminium alloy.SOLUTION: A clad material 30 is prepared as at least one member of a first member and a second member in which an intermediate layer 32 and a surface layer 33 are laminated in this order on a core material layer 31. The surface layer 33 is composed of an aluminium-silicon alloy. The intermediate layer 32 is composed of an aluminium alloy containing magnesium and bismuth. The first member and the second member are assembled with each other with the surface layer 33 side as a joined object. The first member and the second member are brazed with each other under low oxygen concentration environment such that concentration of oxygen is lower than concentration of oxygen in the air under the ambient pressure or a pressure higher than the ambient pressure in a state where a flux is not applied onto surfaces of each of the first member and the second member.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger and a manufacturing method thereof.

  As a conventional heat exchanger, there is one disclosed in Patent Document 1. This heat exchanger includes a plurality of stacked cooling pipes. Each of the plurality of cooling pipes has a gap between adjacent cooling pipes. A cooling object is arranged in this gap.

  As a conventional method for producing a heat exchanger, Patent Document 2 discloses a method for performing brazing and joining in a vacuumless environment under a vacuum environment. This is because Mg is destroyed in the surface of the brazing filler metal layer by adding Mg to the brazing filler metal. This is a method that enables good brazing without using flux.

Japanese Patent No. 4552805 Japanese Patent No. 4107931

  The present inventor has disclosed a heat exchange made of an aluminum alloy that can be brazed in a fluxless manner in brazing in a low oxygen concentration environment in which the oxygen concentration is lower than the oxygen concentration in the atmosphere, not in a vacuum environment. The manufacturing method of the vessel was examined. Specifically, brazing using a clad material obtained by clad a brazing material layer composed of an Al—Si alloy containing Mg on a core material layer was examined. The term “low oxygen concentration environment” as used herein refers to an environment in which the concentration of oxygen is made lower than the concentration of oxygen in the atmosphere by means such as filling with an inert gas without evacuation.

However, under a low oxygen concentration environment, Mg present near the surface of the brazing material layer is oxidized to form an Mg oxide film (MgO). For this reason, both an oxide film of Mg and an oxide film of Al (Al ₂ O ₃ ) or an oxide film of Mg exist. Since such an oxide film inhibits brazing, brazing cannot be performed.

  In view of the above points, an object of the present invention is to enable fluxless brazing joining in a low oxygen concentration environment when manufacturing a heat exchanger.

In order to achieve the above object, the invention described in claim 1
A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing the first member (11, 12) and the second member constituting the heat exchanger;
An assembling step of assembling the prepared first member and second member;
A brazing step of brazing and joining the assembled first member and the second member;
In the preparation step, a laminated material (30) is prepared as the first member,
In the laminated material, the intermediate layer (32) and the surface layer (33) made of the brazing material are sequentially laminated on the core material layer (31),
The surface layer is composed of an aluminum-silicon alloy,
The intermediate layer is made of an aluminum alloy containing magnesium and bismuth,
The core material layer is made of an aluminum alloy,
In the assembling step, the first member and the second member are assembled with the surface layer side of the laminated material as the joining counterpart side,
In the brazing step, the first member and the second member are in a low oxygen concentration environment where the oxygen concentration is lower than the oxygen concentration in the atmosphere, and under atmospheric pressure or higher than atmospheric pressure. Brazing and joining are performed without applying flux to each surface.

The invention according to claim 2
A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing the first member (11, 12) and the second member constituting the heat exchanger;
An assembling step of assembling the prepared first member and second member;
A brazing step of brazing and joining the assembled first member and the second member;
In the preparation step, a laminated material (70) is prepared as the first member,
In the laminated material, an intermediate layer (72) composed of a brazing material and a surface layer (73) composed of a brazing material are sequentially laminated on the core material layer (71),
The surface layer is composed of an aluminum-silicon alloy,
The intermediate layer is made of an aluminum-silicon alloy containing magnesium and bismuth,
The core material layer is made of an aluminum alloy,
In the assembling step, the first member and the second member are assembled with the surface layer side of the laminated material as the joining counterpart side,
In the brazing step, the first member and the second member are in a low oxygen concentration environment where the oxygen concentration is lower than the oxygen concentration in the atmosphere, and under atmospheric pressure or higher than atmospheric pressure. Brazing and joining are performed without applying flux to each surface.

  According to the first and second aspects of the invention, since magnesium (Mg) is added to the intermediate layer, not the surface layer, formation of an oxide film of Mg on the surface of the laminated material can be suppressed. Furthermore, bismuth (Bi) in the intermediate layer melts before other components at the time of temperature rise in heating for brazing joining. Until the entire surface layer is in a molten state, the melted Bi suppresses the diffusion of Mg to the surface of the laminated material. For this reason, formation of the oxide film of Mg at the time of brazing can be suppressed. When the entire surface layer is in a molten state, Mg diffuses toward the surface of the laminated material, thereby destroying the oxide film existing on the surface of the laminated material.

  Therefore, according to the present invention, fluxless brazing can be performed in a low oxygen concentration environment.

The invention according to claim 6
A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing a first member (13), a second member, and a third member constituting the heat exchanger;
An assembling step of assembling the prepared first member, second member and third member;
A brazing step of brazing and joining the assembled first member, second member, and third member;
In the preparation step, a laminated material (40) is prepared as the first member,
The laminated material has a first surface layer (42) composed of a brazing material and a second surface layer (43) composed of a brazing material laminated on each of both surfaces of the intermediate layer (41),
Each of the first surface layer and the second surface layer is made of an aluminum-silicon alloy,
The intermediate layer is made of an aluminum alloy containing magnesium and bismuth,
In the assembly process, the first member, the second member, and the third member are assembled such that the first surface layer contacts the second member and the second surface layer contacts the third member,
In the brazing step, the first member and the second member are in a low oxygen concentration environment where the oxygen concentration is lower than the oxygen concentration in the atmosphere, and under atmospheric pressure or higher than atmospheric pressure. And the third member are brazed and joined in a state where no flux is applied.

  According to the sixth aspect of the invention, since magnesium (Mg) is added to the intermediate layer instead of the first and second surface layers, formation of Mg oxide films on the surfaces on both sides of the laminated material can be suppressed. . Furthermore, bismuth (Bi) in the intermediate layer melts before other components at the time of temperature rise in heating for brazing joining. Until the entire first and second surface layers are in a molten state, the melted Bi suppresses diffusion to the surfaces on both sides of the Mg laminate. For this reason, formation of the oxide film of Mg at the time of brazing can be suppressed. When the entire first and second surface layers are in a molten state, Mg diffuses toward the surfaces on both sides of the laminated material, thereby destroying the oxide film present on the surfaces on both sides of the laminated material.

  Therefore, according to the present invention, fluxless brazing can be performed in a low oxygen concentration environment.

The invention according to claim 9 is the invention according to any one of claims 1 to 8,
The first member constitutes at least a part of a space forming member that forms an internal space therein,
In the brazing step, the first member and a member to which the first member is joined are brazed and joined in a state in which the internal space of the space forming member and the external space of the space forming member are separated. It is characterized by that.

  Here, the external space is wider than the internal space. For this reason, there are more oxygens existing in the external space than oxygen existing in the internal space. When Bi is not contained in the first member, the oxide film formed on the outer space side of the surface of the first member is more than the oxide film formed on the inner space side of the surface of the first member. Become thicker.

  According to this, the movement of oxygen from the external space to the surface of the first member can be suppressed by the melted Bi. For this reason, formation of an oxide film can be suppressed on the external space side of the first member. The thicknesses of the oxide films formed on the outer space side and the inner space side of the first member can be made close to the same thickness. As a result, it is possible to satisfactorily braze and join the first member and the second member.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a front view of the heat exchanger in a 1st embodiment. It is the II-II sectional view taken on the line in FIG. It is sectional drawing of the clad material 30 used as an outer shell plate in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the clad material 40 used as an intermediate | middle plate in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the single layer member 50 used as an inner fin in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the surface layer for demonstrating the mechanism of brazing in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the surface layer for demonstrating the mechanism of brazing in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the surface layer for demonstrating the mechanism of brazing in the manufacturing method of the heat exchanger of 1st Embodiment. It is sectional drawing of the clad material 30 used as an outer shell plate in the manufacturing method of the heat exchanger of 2nd Embodiment. It is sectional drawing of the clad material 30 used as an outer shell plate in the manufacturing method of the heat exchanger of 3rd Embodiment. It is sectional drawing of the clad material 30 used as an outer shell plate in the manufacturing method of the heat exchanger of 4th Embodiment. It is sectional drawing of the clad material 70 used as an outer shell plate in the manufacturing method of the heat exchanger of 6th Embodiment. It is sectional drawing of the clad material 70 used as an outer shell plate in the manufacturing method of the heat exchanger of 7th Embodiment. It is sectional drawing of the clad material 70 used as an outer shell plate in the manufacturing method of the heat exchanger of 8th Embodiment. It is sectional drawing of the clad material 70 used as an outer shell plate in the manufacturing method of the heat exchanger of 9th Embodiment. It is sectional drawing of the clad material 30 in other embodiment. It is sectional drawing of the clad material 30 in other embodiment. It is sectional drawing of the clad material 30 in other embodiment. It is sectional drawing of the clad material 30 in other embodiment. It is sectional drawing of the clad material 70 in other embodiment. It is sectional drawing of the clad material 70 in other embodiment. It is sectional drawing of the clad material 70 in other embodiment. It is sectional drawing of the clad material 70 in other embodiment. It is sectional drawing of the clad material 40 in other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
As shown in FIG. 1, the heat exchanger 1 of the present embodiment cools an electronic component 2 as an object to be cooled, and is a stacked heat exchanger including a plurality of stacked tubes 3. The tube stacking direction in FIG. 1 is the stacking direction of the plurality of tubes 3, and the tube longitudinal direction is the longitudinal direction of one tube 3.

  One tube 3 has a flat shape with a small thickness in the tube stacking direction. One tube 3 extends with one direction orthogonal to the tube stacking direction as the tube longitudinal direction. Two adjacent tubes 3 are arranged apart from each other so as to have a gap space S1 for sandwiching the electronic component 2 therebetween. Two adjacent tubes 3 are connected to each other via a communication member 4 located on one end side and both end sides in the tube longitudinal direction. An introduction pipe 5 and a discharge pipe 6 are connected to the tube 3 positioned at the end in the tube stacking direction among the plurality of tubes 3. The introduction pipe 5 is for introducing the refrigerant into the plurality of tubes 3. The discharge pipe 6 is for discharging the refrigerant from the plurality of tubes 3.

  An electronic component 2 is sandwiched between two adjacent tubes 3. An outer surface 3 a of the tube 3 is in contact with the electronic component 2. That is, the tube 3 is connected to the electronic component 2 so as to be able to conduct heat. The electronic component 2 has a flat shape. The electronic component 2 is a semiconductor module that constitutes a part of an automotive inverter. The semiconductor module contains a semiconductor element that controls high power, that is, a power element.

  The refrigerant is distributed from the introduction pipe 5 to each of the plurality of tubes 3. The refrigerant flows through the plurality of tubes 3. At this time, the electronic component 2 is cooled by heat exchange between the refrigerant and the electronic component 2. The refrigerant after the heat exchange is discharged from the discharge pipe 6 to the outside.

  As shown in FIG. 2, one tube 3 has a pair of outer shell plates 11 and 12, an intermediate plate 13, and inner fins 14 and 15.

  The pair of outer shell plates 11 and 12 constitute the outer shell of the tube 3. The pair of outer shell plates 11 and 12 form a space between them. The intermediate plate 13 is disposed between the pair of outer shell plates 11 and 12. The intermediate plate 13 partitions the space between the pair of outer shell plates 11 and 12 into two refrigerant channels. Inner fins 14 are disposed between the outer shell plate 11 and the intermediate plate 13. Inner fins 15 are arranged between the outer shell plate 12 and the intermediate plate 13. The inner fins 14 and 15 promote heat exchange between the refrigerant and the electronic component 2.

  At the outer peripheral edge of the pair of outer shell plates 11 and 12, the outer shell plates 11 and 12 and the intermediate plate 13 are brazed and joined with the pair of outer shell plates sandwiching the intermediate plate. For this reason, the fillets 21 and 22 which join the outer shell plates 11 and 12 and the intermediate plate 13 are formed. In the present embodiment, the outer shell plates 11 and 12 correspond to the first member, and the intermediate plate 13 corresponds to the second member.

  Similarly, the outer shell plates 11 and 12 and the inner fins 14 and 15 are brazed and joined. For this reason, the fillets 23 and 24 which join the outer shell plates 11 and 12 and the inner fins 14 and 15 are formed. In the present embodiment, the outer shell plates 11 and 12 correspond to the first member, and the inner fins 14 and 15 correspond to the second member.

  Similarly, the intermediate plate 13 and the inner fins 14 and 15 are brazed and joined. For this reason, fillets 25 and 26 for joining the intermediate plate 13 and the inner fins 14 and 15 are formed. In the present embodiment, the intermediate plate 13 corresponds to a first member, and the inner fin 14 and the inner fin 15 correspond to a second member and a third member, respectively.

  Next, the manufacturing method of the heat exchanger 1 of this embodiment is demonstrated.

  The manufacturing method of the heat exchanger 1 performs a preparation process, an assembly | attachment process, and a brazing process in order.

  The preparation step is a step of preparing each constituent member constituting the heat exchanger 1. In a preparation process, each structural member which comprises the tube 3, the introduction pipe | tube 5, and the discharge pipe 6 are prepared. The constituent members constituting the tube 3 are a pair of outer shell plates 11 and 12, an intermediate plate 13, and inner fins 14 and 15.

  The assembly process is a process of assembling each prepared component member. In the assembling step, the pair of outer shell plates 11 and 12, the intermediate plate 13, and the inner fins 14 and 15 are assembled to form the temporarily assembled tube 3. At this time, the pair of outer shell plates 11 and 12, the intermediate plate 13, and the inner fins 14 and 15 are temporarily fixed. Further, the plurality of tubes 3, the introduction pipe 5, and the discharge pipe 6 are assembled to form the heat exchanger 1 in a temporarily assembled state. At this time, the adjacent tubes 3 are temporarily fixed.

  The brazing step is a step of brazing and joining the assembled components. In the brazing process, the heat exchanger 1 in the temporarily assembled state is heated. That is, each assembled component member is heated. Thereby, each structural member is brazed and united and integrated.

  In the brazing step, each component is heated in a low oxygen environment where the oxygen concentration around each component is lower than the oxygen concentration in the atmosphere. For this purpose, the heat exchanger 1 in a temporarily assembled state is disposed inside the heating furnace. The heat exchanger 1 is heated in a state where the inside of the heating furnace is filled with an inert gas. Nitrogen is used as the inert gas. In this heating, the air pressure inside the heating furnace is the same as or higher than the atmospheric pressure. Thereby, evaporation of additives such as Mg described later can be prevented. Further, this heating does not evacuate the inside of the heating furnace. In this heating, the flux is not applied to the surface of each constituent member.

  In this heating, the furnace temperature of the heating furnace is raised from the normal temperature to the melting temperature of the brazing material (around 600 ° C.) (temperature raising process). Thereafter, it is held at a constant temperature for a predetermined time (holding process). Thereafter, the heat exchanger is cooled.

  After the brazing process, the electronic component 2 is disposed in the gap space S1 of the heat exchanger 1 that has been joined. Thereby, the heat exchanger 1 shown in FIG. 1 is manufactured.

  In the present embodiment, in the preparation step, as shown in FIG. 3, the intermediate layer 32 and the surface layer 33 are sequentially laminated on the core material layer 31 as the pair of outer shell plates 11 and 12 in a state before brazing and joining. A laminated material, that is, a clad material 30 is prepared. The clad material is a plate-like member obtained by bonding two or more different metals.

  The core material layer 31 is composed of a core material, that is, a base material, and is composed of an Al—Mn alloy. The base material is a material that is brazed and joined by a brazing material. Examples of the Al-Mn alloy include aluminum alloys whose material symbol of the Japanese Industrial Standard (JIS) is in the 3000 series. The intermediate layer 32 is made of a base material, and is made of an aluminum alloy (Al—Mg—Bi alloy) containing magnesium and bismuth. The surface layer 33 is made of a brazing material and is made of an aluminum-silicon alloy (Al-Si alloy).

  Hereinafter, the intermediate layer 32 and the surface layer 33 will be described more specifically.

  The intermediate layer 32 has an addition amount (content) of Mg (magnesium) of 0.1% to 5.0%, and an addition amount (content) of Bi (bismuth) of 0.01% to 2.0%. % Of aluminum alloy. The numerical value (%) indicating the added amount of Mg and Bi indicates the mass% (mass%) of Mg and Bi with respect to the entire aluminum alloy constituting the intermediate layer 32.

  By making the addition amount of Mg 0.1% or more, Mg diffuses into the surface layer, and an oxide film destruction effect can be produced. The mechanical properties can be improved as the amount of Mg added increases. However, if the amount added is too large, erosion is likely to occur, and the workability at the time of component molding is reduced. Erosion is the dissolution of an aluminum alloy base material into a molten brazing material and the diffusion of brazing material components into the base material. Therefore, by setting the amount of Mg to be 5.0% or less, generation of erosion can be suppressed, and deterioration of workability during component molding can be suppressed. Moreover, favorable brazing property is acquired as shown in the below-mentioned Example by making Bi addition amount into 0.01% or more and 2.0% or less.

  The surface layer 33 is an aluminum alloy having an addition amount (content) of Si (silicon) of 5% or more and 13.0% or less. The numerical value (%) indicating the addition amount of Si indicates the mass% (mass%) of Si with respect to the entire aluminum alloy constituting the surface layer 33. The reason why the Si addition amount is 5.0% or more and 13.0% or less is to keep the Al—Si alloy within the range of hypoeutectic, and when the addition amount of Si exceeds 13.0%, it is the first time. This is because crystal Si appears and the erosion risk increases.

  In the preparation step, as the intermediate plate 13, as shown in FIG. 4, a clad material 40 in which a first surface layer 42 and a second surface layer 43 are laminated on each of both surfaces of the intermediate layer 41 is prepared. . The intermediate layer 41 is made of a base material and made of an Al—Mn—Mg—Bi alloy. Each of the first surface layer 42 and the second surface layer 43 is made of a brazing material, and is made of an Al—Si based alloy. In the present embodiment, the clad material 40 corresponds to a laminated material. In the following description, the first and second surface layers 42 and 43 may be simply referred to as surface layers 42 and 43.

  The contents of Mg and Bi contained in the aluminum alloy constituting the intermediate layer 41 are the same as those of the intermediate layer 32 of the clad material 30. The content of Si contained in the aluminum alloy constituting the first and second surface layers 42 and 43 is the same as that of the surface layer 33 of the cladding material 30.

  In the preparation step, as the inner fins 14 and 15, as shown in FIG. 5, a single layer of an Al—Mn alloy, an Al—Mn—Mg alloy, or an Al—Mn—Mg—Bi alloy (that is, A single layer member 50 made of a core material is prepared.

  In the assembling process, the surface layer 33 side of the cladding material 30 is assembled as the bonding partner side so that the surface layer 33 of the cladding material 30 contacts the bonding partner. That is, the outer shell plates 11, 12 and the intermediate plate 13 are assembled with the surface layer 33 side of the clad material 30 constituting the outer shell plates 11, 12 as the intermediate plate 13 side. Similarly, the outer shell plates 11 and 12 and the inner fins 14 and 15 are assembled with the surface layer 33 side of the clad material 30 as the inner fins 14 and 15 side.

  In assembling the intermediate plate 13 and the inner fins 14, 15, the intermediate plate 13 and the inner fins are arranged such that the first surface layer 42 of the clad material 40 contacts the inner fin 14 and the second surface layer 43 contacts the inner fin 15. 14 and 15 are assembled.

  Next, the brazing process will be described. In the brazing step, the furnace temperature of the heating furnace is raised from room temperature to the melting temperature of the brazing material (temperature raising process). Thereafter, it is held at a constant temperature for a predetermined time (holding process). Thereafter, the heat exchanger is cooled.

  First, the mechanism of brazing of the clad material 30 constituting the outer shell plates 11 and 12 will be described.

Before heating, an Al oxide film (Al ₂ O ₃ ) 61 exists on the surface of the surface layer 33 as shown in FIG. Since the surface layer 33 does not contain Mg, there is no Mg oxide film on the outermost surface of the surface layer 33.

  When the temperature rises to 450 ° C. or higher in the temperature raising process, the Bi component in the intermediate layer 32 starts to melt. Bi has a lower melting point than the Al-Si alloy. For this reason, Bi melts before the Al—Si alloy. The molten Bi, that is, the Bi melt moves to the surface side of the surface layer 33.

  When the temperature rises to 540 ° C. or higher, a Bi melt layer 62, which is a Bi melt layer, is formed between the oxide film 61 and the surface layer 33 as shown in FIG. Furthermore, a BiMg melt layer 63, which is a layer of Bi and Mg melt, is formed between the oxide film 61 and the surface layer 33.

  Thus, the Bi melt layer 62 and the BiMg melt layer 63 cover the surface layer 33 inside the oxide film 61. For this reason, the diffusion of Mg from the intermediate layer 32 to the surface of the surface layer 33 is prevented. Therefore, the formation of the Mg oxide film on the surface of the surface layer 33 is suppressed.

  When the temperature rises to the melting temperature of the brazing material, as shown in FIG. 8, the surface layer 33 is melted (liquefied) to become a melt. When the melts of the Bi melt layer 62 and the BiMg melt layer 63 are mixed with the melt of the brazing material, Mg diffuses toward the surface of the surface layer 33. The oxide film 61 is destroyed by Mg. Thereby, favorable brazing becomes possible.

  In the cooling process, the melt is solidified so that the contact portions between the outer shell plates 11 and 12 and the intermediate plate 13 are joined, and the contact portions between the outer shell plates 11 and 12 and the inner fins 14 and 15. Are joined. That is, as shown in FIG. 2, fillets 21 and 22 are formed at the brazed joints between the outer shell plates 11 and 12 and the intermediate plate 13, and the outer shell plates 11 and 12 and the inner fins 14 and 15 are connected to each other. Fillets 23 and 24 are formed at the brazed joint. The fillets 21, 22, 23, and 24 are made of an aluminum alloy containing Bi, Mg, and Si.

  The mechanism of brazing of the clad material 40 constituting the intermediate plate 13 is the same as that of the clad material 30 constituting the outer shell plates 11 and 12. Since the phenomena that occur in the surface layers 33, 42, and 43 are the same, the reference numerals 33, 42, and 43 are assigned to the surface layers in FIGS.

  That is, when the temperature rises to 450 ° C. or higher in the temperature raising process, the Bi component in the intermediate layer 41 starts to melt.

  When the temperature rises to 540 ° C. or higher, a Bi layer 62 made of a Bi melt is formed between the oxide film 61 and the first and second surface layers 42 and 43 as shown in FIG. For this reason, the diffusion of Mg to the surfaces of the first and second surface layers 42 and 43 is prevented.

  When the temperature rises to be equal to or higher than the melting temperature of the wax, as shown in FIG. 8, the first and second surface layers 42 and 43 are melted to become a melt. By mixing the melt of Bi with the melt of Bi (that is, the Bi melt layer 62 and the BiMg melt layer 63), Mg diffuses toward the surfaces of the first and second surface layers 42 and 43. The oxide film 61 is destroyed by Mg. Thereby, favorable brazing becomes possible.

  In the cooling process, the melt is solidified to join the contact portions of the intermediate plate 13 and the inner fins 14 and 15. That is, as shown in FIG. 2, fillets 25 and 26 are formed at the brazed joint between the intermediate plate 13 and the inner fins 14 and 15. The fillets 25 and 26 are made of an aluminum alloy containing Bi, Mg, and Si.

  As described above, in this embodiment, Mg is added to the intermediate layers 32 and 41 instead of the surface layers 33, 42, and 43 of the clad materials 30 and 40. For this reason, formation of the oxide film of Mg on the surface of the surface layers 33, 42, and 43 before heating can be suppressed. Furthermore, Bi in the intermediate layers 32 and 41 is melted before other components at the time of heating and heating for brazing. The molten Bi suppresses the diffusion of Mg to the surface. For this reason, formation of the oxide film of Mg at the time of heating temperature rising can be suppressed. When the entire surface layers 33, 42, 43 are in a molten state, Mg diffuses to the surface side of the surface layers 33, 42, 43, thereby destroying the oxide film 61. That is, until the brazing material is melted, the Bi melt suppresses the diffusion of Mg to the surfaces of the surface layers 33, 42, and 43. When the brazing material is melted, the Mg oxide film destruction effect is obtained.

  Thereby, according to this embodiment, it can be satisfactorily brazed and joined in a fluxless manner in a low oxygen environment.

  In the present embodiment, the clad material 30 is used as the outer shell plates 11 and 12. The outer shell plates 11 and 12 are brazed to the intermediate plate 13 to form a space with the intermediate plate 13. Therefore, the outer shell plates 11 and 12 and the intermediate plate 13 are space forming members that form an internal space inside. The outer shell plates 11 and 12 constitute a part of the space forming member. For this reason, in the brazing process, the outer shell plates 11 and 12 and the intermediate plate 13 that is a member of the outer shell plates 11 and 12 are connected to the inner space between the outer shell plates 11 and 12 and the intermediate plate 13, and the outer shell plate 11, 12 and the external space outside the intermediate plate 13 are separated by brazing.

  Here, the external space is wider than the internal space. For this reason, there are more oxygens existing in the external space than oxygen existing in the internal space. When Bi is not contained in the cladding material 30, the oxide film formed on the outer space side of the surface of the cladding material 30 is more than the oxide film formed on the inner space side of the surface of the cladding material 30. Become thicker.

  On the other hand, in this embodiment, Bi is contained in the intermediate layer 32 of the clad material 30. Thereby, the movement of oxygen from the external space to the surface of the clad material 30 can be suppressed by the molten Bi during heating. For this reason, formation of an oxide film can be suppressed on the outer space side of the surface of the clad material 30. In other words, the thickness of the oxide film formed on each of the outer space side and the inner space side of the clad material 30 can be made closer to the same thickness. As a result, the outer shell plates 11 and 12 and the intermediate plate 13 can be satisfactorily brazed.

(Second Embodiment)
As shown in FIG. 9, the present embodiment differs from the first embodiment in the composition of the aluminum alloy constituting the intermediate layer 32 of the clad material 30. The composition of the aluminum alloy constituting the core material layer 31 and the surface layer 33 is the same as that of the cladding material 30 of the first embodiment.

  In the present embodiment, the intermediate layer 32 is made of an Al—Mg—Bi—Zn alloy. The amount of Zn added is preferably 0.02%, which can be discriminated as an additive, as the lower limit, and more. The amount of Zn added is preferably 6% or less, at which the intermediate layer 32 can exert an effect as a sacrificial layer, and less than that. The sacrificial layer is a layer that functions to suppress corrosion of the core material layer 31 by preferentially corroding the core material layer 31. When 6% or more is added, the corrosion resistance of the material is significantly reduced. The numerical value (%) indicating the added amount of Zn indicates the mass% (mass%) of Zn with respect to the entire aluminum alloy constituting the intermediate layer 32.

  Also in this embodiment, the same effect as the first embodiment can be obtained.

(Third embodiment)
As shown in FIG. 10, the present embodiment differs from the first embodiment in the composition of the aluminum alloy constituting the surface layer 33 of the cladding material 30. The composition of the aluminum alloy constituting the core material layer 31 and the intermediate layer 32 is the same as that of the clad material 30 of the first embodiment.

  In the present embodiment, the surface layer 33 is made of an Al—Si—Zn alloy. The amount of Zn added is preferably 0.02%, which can be discriminated as an additive, as the lower limit, and more. Further, the amount of Zn added is preferably 6% or less, at which the surface layer 33 can exert an effect as a sacrificial layer, and is less than that. When 6% or more is added, the corrosion resistance of the material is significantly reduced. The numerical value (%) indicating the added amount of Zn indicates the mass% (mass%) of Zn with respect to the entire aluminum alloy constituting the surface layer 33.

  Also in this embodiment, the same effect as the first embodiment can be obtained.

(Fourth embodiment)
As shown in FIG. 11, this embodiment differs in the composition of the aluminum alloy which comprises the core material layer 31 of the clad material 30 with respect to 1st Embodiment. The composition of the aluminum alloy constituting the intermediate layer 32 and the surface layer 33 is the same as that of the cladding material 30 of the first embodiment.

  In the present embodiment, the core material layer 31 is made of an Al—Mn—Mg alloy. Thus, Mg may be added to the core material layer 31. Also in this embodiment, the same effect as the first embodiment can be obtained. In the second and third embodiments, Mg may be added to the core material layer 31 as in the present embodiment.

(Fifth embodiment)
The present embodiment differs from the first embodiment in the members used as the intermediate plate 13 and the inner fins 14 and 15, respectively.

  In the present embodiment, the single layer member 50 shown in FIG. 5 is prepared as the intermediate plate 13 in the preparation step. As the inner fins 14 and 15, a clad material 40 shown in FIG. Also in this embodiment, similarly to the first embodiment, the intermediate plate 13 and the inner fins 14 and 15 are well brazed and joined.

  In the present embodiment, the clad material 30 constituting the outer shell plates 11 and 12 and the single layer member 50 constituting the intermediate plate 13 are brazed and joined. Even in this case, the same effect as the first embodiment can be obtained.

(Sixth embodiment)
In the present embodiment, a clad material 70 shown in FIG. 12 is used instead of the clad material 30 of the first embodiment. That is, in the present embodiment, in the preparation step, a clad material 70 in which an intermediate layer 72 and a surface layer 73 are sequentially laminated on a core material layer 71 is prepared as a pair of outer shell plates 11 and 12 in a state before brazing joining. To do.

  The core material layer 71 is the same as the core material layer 31 of the clad material 30 of the first embodiment. The intermediate layer 72 is made of a brazing material, and is made of an aluminum-silicon alloy (Al—Si—Mg—Bi alloy) containing magnesium and bismuth. The surface layer 73 is made of a brazing material and is made of an aluminum-silicon alloy (Al—Si alloy). In the present embodiment, the clad material 70 corresponds to a laminated material.

  Thus, the clad material 70 has two brazing material layers. Of the two brazing filler metal layers, magnesium and bismuth are contained in the intermediate layer 72 which is an inner brazing filler metal layer. The brazing mechanism of the clad material 70 is the same as that of the clad material 30 of the first embodiment. The surface layer 33 in FIGS. 6, 7, and 8 corresponds to the surface layer 73 of the cladding material 70 of the present embodiment. Therefore, also in this embodiment, the same effect as the first embodiment can be obtained.

(Seventh embodiment)
As shown in FIG. 13, this embodiment differs in the composition of the aluminum alloy which comprises the intermediate | middle layer 72 of the clad material 70 with respect to 6th Embodiment. The composition of the aluminum alloy constituting the core material layer 71 and the surface layer 73 is the same as that of the clad material 70 of the sixth embodiment.

  In the present embodiment, Zn is added to the aluminum alloy constituting the intermediate layer 72 as in the second embodiment. That is, the intermediate layer 72 is made of an Al—Si—Mg—Bi—Zn alloy. The amount of Zn added is the same as in the second embodiment. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Eighth embodiment)
As shown in FIG. 14, this embodiment differs in the composition of the aluminum alloy which comprises the surface layer 33 of the clad material 70 with respect to 6th Embodiment. The composition of the aluminum alloy constituting the core material layer 71 and the intermediate layer 72 is the same as that of the clad material 70 of the sixth embodiment.

  In the present embodiment, Zn is added to the aluminum alloy constituting the surface layer 73 as in the third embodiment. That is, the surface layer 73 is made of an Al—Si—Zn alloy. The amount of Zn added is the same as in the third embodiment. Also in this embodiment, the same effect as the first embodiment can be obtained.

(Ninth embodiment)
As shown in FIG. 15, this embodiment differs in the composition of the aluminum alloy which comprises the core material layer 71 of the clad material 70 with respect to 6th Embodiment. The composition of the aluminum alloy constituting the intermediate layer 72 and the surface layer 73 is the same as that of the cladding material 70 of the sixth embodiment.

  In the present embodiment, similarly to the fourth embodiment, Mg is added to the aluminum alloy constituting the core material layer 71. That is, the core material layer 71 is made of an Al—Mn—Mg alloy. Also in this embodiment, the same effect as the first embodiment can be obtained. In the seventh and eighth embodiments, Mg may be added to the core material layer 71 as in the present embodiment.

(Other embodiments)
(1) In the first to fourth embodiments, Bi is not included in the aluminum alloy constituting the surface layer 33 of the clad material 30, but Bi is included as shown in FIGS. 16, 17, 18, and 19. It may be.

  In the clad material 30 shown in FIG. 16, the surface layer 33 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 31 and the intermediate layer 32 is the same as that of the cladding material 30 of the first embodiment shown in FIG.

  In the clad material 30 shown in FIG. 17, the surface layer 33 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 31 and the intermediate layer 32 is the same as that of the clad material 30 of the second embodiment shown in FIG.

  In the clad material 30 shown in FIG. 18, the surface layer 33 is made of an Al—Si—Bi—Zn alloy. The composition of the aluminum alloy constituting the core material layer 31 and the intermediate layer 32 is the same as that of the clad material 30 of the third embodiment shown in FIG.

  In the clad material 30 shown in FIG. 19, the surface layer 33 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 31 and the intermediate layer 32 is the same as that of the clad material 30 of the fourth embodiment shown in FIG. In the clad material 30 shown in FIGS. 11 and 19, the Mg content in the aluminum alloy constituting the core material layer 31 is preferably 0.02 mass% or more and 3.0 mass% or less. Thereby, as shown in the Example mentioned later, generation | occurrence | production of erosion can be avoided.

  In any case of FIGS. 16 to 19, the Bi content of the aluminum alloy constituting the surface layer 33 is preferably 0.01% by mass or more and 1.0% by mass or less. Thereby, as shown in the Example mentioned later, favorable brazing is attained.

  (2) In the sixth to ninth embodiments, Bi is not included in the aluminum alloy constituting the surface layer 73 of the clad material 70, but Bi is included as shown in FIGS. It may be.

  In the clad material 70 shown in FIG. 20, the surface layer 73 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 71 and the intermediate layer 72 is the same as that of the clad material 70 of the sixth embodiment shown in FIG.

  In the cladding material 70 shown in FIG. 21, the surface layer 73 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 71 and the intermediate layer 72 is the same as that of the cladding material 70 of the seventh embodiment shown in FIG.

  In the clad material 70 shown in FIG. 22, the surface layer 73 is made of an Al—Si—Bi—Zn alloy. The composition of the aluminum alloy constituting the core material layer 71 and the intermediate layer 72 is the same as that of the clad material 70 of the eighth embodiment shown in FIG.

  In the clad material 70 shown in FIG. 23, the surface layer 73 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the core material layer 71 and the intermediate layer 72 is the same as that of the clad material 70 of the ninth embodiment shown in FIG.

  20-23, the content of Bi in the aluminum alloy constituting the surface layer 33 is preferably 0.01% by mass or more and 1.0% by mass or less. Thereby, favorable brazing becomes possible.

  (3) In the first embodiment, as shown in FIG. 4, the aluminum alloy constituting the first and second surface layers 42 and 43 of the clad material 40 does not contain Bi, but as shown in FIG. Bi may be included. In the clad material 40 shown in FIG. 24, each of the first and second surface layers 42 and 43 is made of an Al—Si—Bi alloy. The composition of the aluminum alloy constituting the intermediate layer 41 is the same as that of the cladding material 40 of the first embodiment shown in FIG.

  (4) In each of the above embodiments, the aluminum alloy constituting each of the surface layer 33 of the cladding material 30, the surface layer 73 of the cladding material 70 and the first and second surface layers 42 and 43 of the cladding material 40 contains other elements. It may be.

  (5) In each of the above embodiments, the aluminum alloy constituting each of the intermediate layer 32 of the cladding material 30, the intermediate layer 72 of the cladding material 70 and the intermediate layer 41 of the cladding material 40 may contain other elements. Good.

  (6) In the first to fourth embodiments and the other embodiment (1), the aluminum alloy constituting the core material layer 31 of the clad material 30 is an Al—Mn alloy or an Al—Mn—Mg alloy. However, other elements may be further included, and other elements may be included instead of Mn. Similarly, in the first, fifth and other embodiments (3), the aluminum alloy constituting the intermediate layer 41 of the clad material 40 is an Al—Mn—Mg—Bi-based alloy. These elements may be included, and other elements may be included instead of Mn. Similarly, in the sixth to ninth embodiments and other embodiment (2), the aluminum alloy constituting the core material layer 71 of the clad material 70 is an Al—Mn alloy or an Al—Mn—Mg alloy. However, other elements may be further included, and other elements may be included instead of Mn.

  (7) In each of the above embodiments, the tube 3 has the intermediate plate 13, but may not have the intermediate plate 13. One tube 3 may be formed by brazing a pair of outer shell plates 11 and 12 together. In this case, the clad members 30 constituting the pair of outer shell plates 11 and 12 are joined together. Both of the two clad materials 30 have the surface layer 33 as a bonding counterpart.

  (8) In each of the above embodiments, the clad material 30 or the clad material 70 is used as the outer shell plates 11 and 12, but the present invention is not limited to this. The clad material 30 or the clad material 70 may be used as another constituent member constituting the heat exchanger. In this case, at least one of the two members made of aluminum alloy to be brazed to each other only needs to be constituted by the clad material 30 or the clad material 70. Heating is performed with the clad material 30 or the clad material 70 in contact with the mating member, with the surface layer 33 side as the mating mating side.

  Further, instead of the clad material 30, a laminate material in which another layer is further laminated on the core material layer 31 side of the clad material 30 may be used. Similarly, instead of the clad material 70, a laminate material in which another layer is further laminated on the core material layer 71 side of the clad material 70 may be used.

  In the first embodiment, the clad material 40 is used as the intermediate plate 13, and in the fifth embodiment, the clad material 40 is used as the inner fin 14. However, the present invention is not limited to this. You may use the clad material 40 as another structural member which comprises a heat exchanger. In this case, it suffices that at least one of the two aluminum alloy members to be brazed to each other is made of the clad material 40. Moreover, the cladding material 40 can also be used as a part of space formation member similarly to the cladding material 30 of 1st Embodiment. Also by this, the movement of oxygen from the external space to the surface of the clad material 40 can be suppressed by Bi melted from the intermediate layer 41 during heating. For this reason, formation of an oxide film can be suppressed on the external space side of the surface of the clad material 40. Therefore, the space forming member can be satisfactorily brazed and joined.

  (9) The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope described in the claims, and includes various modifications and modifications within the equivalent range. Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. In each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., unless otherwise specified, or in principle limited to a specific material, shape, positional relationship, etc. The material, shape, positional relationship, etc. are not limited.

Examples of the present invention will be described below.
(Example 1-11 and Comparative Example 1-3)
The brazing properties of the cladding materials 30 of Examples 1-11 and Comparative Examples 1-3 shown in Tables 1, 2, and 3 were evaluated. The clad material 30 of Example 1-11 corresponds to the clad material 30 of the first embodiment shown in FIG. In each of the cladding materials 30 of Example 1-11 and Comparative Example 1-3, the intermediate layer 32 is an Al—Mg—Bi alloy. These clad materials 30 differ in the amount of Bi and Mg added to the aluminum alloy constituting the intermediate layer 32, and the composition of the aluminum alloy constituting the surface layer 33 is the same.

  In Tables 1, 2, and 3, the unit of the added amount of each component of the intermediate layer 32 is mass%, and the balance of the aluminum alloy is Al and inevitable impurities. The surface layer 33 is an aluminum alloy (10Si—Al) in which the addition amount of Si is 10.0 mass% and the balance is Al and inevitable impurities. The core material layer 31 is an Al—Mn alloy. As a counterpart member for brazing and joining the clad material 30, a member made of an aluminum alloy not containing a brazing material was used.

  After assembling the clad material 30 processed into a predetermined shape and the mating member, brazing was performed in a low oxygen concentration environment and at atmospheric pressure without using a flux. This brazing method is as described in the first embodiment. Specifically, in a state where the inside of the heating furnace is filled with nitrogen gas, the internal temperature of the heating furnace is raised to the melting temperature of the brazing material and held at a certain temperature for a predetermined time, and then the clad material 30 and the counterpart member Cooled.

  The brazing property was evaluated based on the fillet size. The evaluation results of brazing properties are as shown in Tables 1, 2, and 3. A circle in the table indicates that the brazing property was good. ◎ in the table indicates that the brazing property was particularly good. That is, ◎ in the table indicates that a fillet having the same size as the fillet formed when brazed by the conventional nocollock method using a flux is formed. X in the table indicates that the brazability was poor.

  As shown in Tables 1, 2, and 3, when the addition amount of Bi is 0.01%, 1.0%, or 2.0%, the addition amount of Mg is 0.1% or more and 5.0%. The brazing property was good at the following times. Although not shown in the table, when the addition amount of Bi is more than 2.0%, the brazing property is poor regardless of the addition amount of Mg. Moreover, when the added amount of Mg exceeded 5%, the workability at the time of molding the parts was lowered. For these reasons, in the intermediate layer 32, the addition amount of Bi is preferably 0.01% or more and 2.0% or less, and the addition amount of Mg is preferably 0.1% or more and 5.0% or less.

  Further, as shown in Table 2, when the addition amount of Bi was 1.0% and the addition amount of Mg was 0.2% and 3.0%, the brazing property was particularly good. . Therefore, the addition amount of Bi is 1.0%, and the addition amount of Mg is more preferably 0.2% or more and 3.0% or less.

(Comparative Example 4-7)
The brazing property of the clad material of Comparative Example 4-7 shown in Table 4 was evaluated. The brazing method and the brazing property evaluation method are the same as those in Example 1-11. The clad material of Comparative Example 4-7 is different from the clad material 30 of Example 1-3 and Comparative Example 1 in that Bi is not added to the intermediate layer 32. The composition of the aluminum alloy constituting the surface layer 33 is the same as that of the clad material 30 of Example 1-3 and Comparative Example 1.

  As shown in Table 4, all of the clad materials of Comparative Examples 4-7 had poor brazing properties.

(Examples 12-22 and Comparative Example 8-10)
The brazing properties of the cladding materials 30 of Examples 12-22 and Comparative Examples 8-10 shown in Tables 5, 6, and 7 were evaluated. The brazing method and the brazing property evaluation method are the same as those in Example 1-11. In the clad material 30 of Examples 12-22 and Comparative Examples 8-10, the surface layer 33 is an Al—Si—Bi-based alloy, and Bi is added to the surface layer 33. Example 1-11 and Comparative Example Different from the 1-3 clad material 30. The clad material 30 of Examples 12-22 corresponds to the clad material 30 of the other embodiment (1) shown in FIG. Each of the clad materials 30 of Examples 12-22 and Comparative Examples 8-10 has different amounts of Bi and Mg added to the aluminum alloy constituting the intermediate layer 32, and has the same composition of the aluminum alloy constituting the surface layer 33. .

  In Tables 5, 6, and 7, the unit of addition amount of each component of the intermediate layer 32 is mass% (mass%), and the balance of the aluminum alloy is Al and inevitable impurities. The surface layer 33 is an aluminum alloy (0.1Bi-10Si-Al) in which the addition amount of Bi is 0.1 mass%, the addition amount of Si is 10.0 mass%, and the balance is Al and inevitable impurities. The core material layer 31 is an Al—Mn alloy.

  As shown in Tables 5, 6, and 7, when the addition amount of Bi is 0.01%, 1.0%, or 2.0%, the addition amount of Mg is 0.1% or more and 5.0%. The brazing property was good at the following times. Although not shown in the table, when the addition amount of Bi is more than 2.0%, the brazing property is poor regardless of the addition amount of Mg. Moreover, when the added amount of Mg exceeded 5%, the workability at the time of component molding was low, and the molded product before brazing was cracked. For these reasons, in the intermediate layer 32, the addition amount of Bi is preferably 0.01% or more and 2.0% or less, and the addition amount of Mg is preferably 0.1% or more and 5.0% or less.

  Further, as shown in Table 5, when the addition amount of Bi was 0.01% and the addition amount of Mg was 0.1% and 0.5%, the brazing property was particularly good. Therefore, the addition amount of Bi is 0.01%, and the addition amount of Mg is more preferably 0.1% or more and 0.5% or less.

Moreover, as shown in Tables 6 and 7, when the addition amount of Bi is 1.0% or 2.0%, the addition amount of Mg is 0.2% or 3.0%. The property was particularly good. Therefore, the addition amount of Bi is 1.0% or more and 2.0% or less, and the addition amount of Mg is more preferably 0.2% or more and 3.0% or less.

(Examples 23-25 and Comparative Example 11)
The brazing properties of the clad members 30 of Examples 23-25 and Comparative Example 11 shown in Table 8 were evaluated. The brazing method and the brazing property evaluation method are the same as those in Example 1-11. The clad material 30 of Examples 23-25 corresponds to the clad material 30 of the other embodiment (1) shown in FIG. 16, similarly to the clad material 30 of Examples 12-22. In each of the clad materials 30 of Examples 23-25 and Comparative Example 11, the surface layer 33 is an Al—Si—Bi alloy, the amount of Bi added to the aluminum alloy constituting the surface layer 33 is different, and the amount of Si added Are the same. The composition of the aluminum alloy constituting the intermediate layer 32 is the same. In addition, in FIG. 8, the evaluation result of Example 2 is also shown.

  In Table 8, the unit of addition amount of each component is mass% (mass%), and the balance of the aluminum alloy is Al and inevitable impurities. The intermediate layer 32 is an aluminum alloy (0.5Mg-0.01Bi-Al) in which the addition amount of Mg is 0.5 mass%, the addition amount of Bi is 0.01 mass%, and the balance is Al and inevitable impurities. is there.

  As shown in Table 8, when the addition amount of Bi was 0.01%, 0.1%, and 1.0%, the brazing property was good. Therefore, in the surface layer 33, the addition amount of Bi is preferably 0.01% or more and 1.0% or less. Further, when the added amount of Bi was 0.01% and 0.1%, the brazing property was particularly good. Therefore, in the surface layer 33, the addition amount of Bi is more preferably 0.01% or more and 0.1% or less.

(Examples 26-31 and Comparative Examples 12 and 13)
The presence or absence of erosion during the brazing of the clad materials 30 of Examples 26-31 and Comparative Examples 12 and 13 shown in Tables 9 and 10 was evaluated. The brazing method is the same as in Example 1-11. To evaluate the occurrence of erosion, the structure of the cross section after brazing was observed. The clad material 30 of Examples 26-31 corresponds to the clad material 30 of the other embodiment (1) shown in FIG. Each of the clad materials 30 of Examples 26-31 and Comparative Examples 12 and 13 differs in the amount of Mg added to the intermediate layer 32 or the amount of Mg added to the core material layer 31.

  In Tables 9 and 10, the unit of the added amount of each component of the intermediate layer 32 is mass%, and the balance of the aluminum alloy is Al and inevitable impurities. The core material layer 31 is an Al—Mn—Mg alloy, and the unit of the amount of Mg added to the core material layer is mass% (mass%). The surface layer 33 is an aluminum alloy (0.1Bi-10Si-Al) in which the addition amount of Bi is 0.1 mass%, the addition amount of Si is 10.0 mass%, and the balance is Al and inevitable impurities.

  As shown in Tables 9 and 10, erosion did not occur when the amount of Mg added to the core layer 31 was 0.02%, 0.2%, or 3.0%. Therefore, in the core material layer 31, the addition amount of Mg is preferably 0.02% or more and 3.0% or less.

  In addition, it is thought that the results of Table 1 to Table 8 were obtained by the Bi component and the Mg component included in the intermediate layer 32. Therefore, it is considered that the same results as in Tables 1 to 8 can be obtained even when the intermediate layer 32 includes other components, not limited to the above-described examples. The same applies to the results in Table 9.

  Further, when the surface layers 42 and 43 of the cladding material 40 and the intermediate layer 41 of the first embodiment and the like have the same composition as the surface layer 33 and the intermediate layer 32 of the cladding material 30, the same as in Tables 1 to 8 It is thought that the result of is obtained.

  Further, as described above, the cladding material 70 according to the sixth to ninth embodiments is different from the cladding 70 according to the first to fourth embodiments only in that the intermediate layer 72 contains Si. Therefore, even when the surface layer 73 and the intermediate layer 72 of the cladding material 70 have the same composition as the surface layer 33 and the intermediate layer 32 of the cladding material 30 except that the intermediate layer 72 contains Si, Table 1 -The same results as in Table 9 are considered to be obtained.

11 outer shell plate 12 outer shell plate 13 intermediate plate 30, 70 clad material 31, 71 core material layer 32, 72 intermediate layer 33, 73 surface layer

Claims (10)

A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing a first member (11, 12) and a second member constituting the heat exchanger;
An assembling step of assembling the prepared first member and the second member;
A brazing step of brazing and joining the assembled first member and the second member;
In the preparation step, a laminate (30) is prepared as the first member,
The laminated material has an intermediate layer (32) and a surface layer (33) made of a brazing material, which are sequentially laminated with respect to the core material layer (31).
The surface layer is made of an aluminum-silicon alloy,
The intermediate layer is made of an aluminum alloy containing magnesium and bismuth,
The core layer is made of an aluminum alloy,
In the assembly process, the first member and the second member are assembled with the surface layer side of the laminated material as a bonding counterpart side,
In the brazing step, the oxygen concentration is a low oxygen concentration environment lower than the oxygen concentration in the atmosphere, the atmospheric pressure or the pressure higher than the atmospheric pressure, and the first member and the The manufacturing method of the heat exchanger which brazes and joins in the state which does not apply | coat a flux to each surface of a 2nd member. A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing a first member (11, 12) and a second member constituting the heat exchanger;
An assembling step of assembling the prepared first member and the second member;
A brazing step of brazing and joining the assembled first member and the second member;
In the preparation step, a laminate (70) is prepared as the first member,
In the laminated material, an intermediate layer (72) composed of a brazing material and a surface layer (73) composed of a brazing material are sequentially laminated on the core material layer (71),
The surface layer is made of an aluminum-silicon alloy,
The intermediate layer is composed of an aluminum-silicon alloy containing magnesium and bismuth,
The core layer is made of an aluminum alloy,
In the assembly process, the first member and the second member are assembled with the surface layer side of the laminated material as a bonding counterpart side,
In the brazing step, the oxygen concentration is a low oxygen concentration environment lower than the oxygen concentration in the atmosphere, the atmospheric pressure or the pressure higher than the atmospheric pressure, and the first member and the The manufacturing method of the heat exchanger which brazes and joins in the state which does not apply | coat a flux to each surface of a 2nd member.   The content of magnesium in the aluminum alloy constituting the intermediate layer is 0.1% by mass or more and 5.0% by mass or less, and the content of bismuth in the aluminum alloy constituting the intermediate layer is 0.01% by mass. The method for producing a heat exchanger according to claim 1 or 2, wherein the content is 2.0% by mass or less.   The aluminum alloy which comprises the said surface layer is a manufacturing method of the heat exchanger as described in any one of Claim 1 thru | or 3 which further contains 0.01 mass% or more and 1.0 mass% or less of bismuth.   The method for manufacturing a heat exchanger according to any one of claims 1 to 4, wherein the aluminum alloy constituting the core material layer further contains magnesium in an amount of 0.02 mass% to 3.0 mass%. A method for manufacturing a heat exchanger made of aluminum alloy,
A preparation step of preparing a first member (13), a second member, and a third member constituting the heat exchanger;
An assembling step of assembling the prepared first member, the second member, and the third member;
A brazing step of brazing and joining the assembled first member, the second member, and the third member;
In the preparation step, a laminate (40) is prepared as the first member,
The laminated material has a first surface layer (42) composed of a brazing material and a second surface layer (43) composed of a brazing material laminated on each of both surfaces of the intermediate layer (41),
Each of the first surface layer and the second surface layer is made of an aluminum-silicon alloy,
The intermediate layer is made of an aluminum alloy containing magnesium and bismuth,
In the assembling step, the first member, the second member, and the third member are assembled such that the first surface layer is in contact with the second member and the second surface layer is in contact with the third member. ,
In the brazing step, the oxygen concentration is a low oxygen concentration environment lower than the oxygen concentration in the atmosphere, the atmospheric pressure or the pressure higher than the atmospheric pressure, and the first member and the The manufacturing method of the heat exchanger which brazes and joins in the state which does not apply | coat a flux to each surface of a 2nd member and the said 3rd member.   The content of magnesium in the aluminum alloy constituting the intermediate layer is 0.1% by mass or more and 5.0% by mass or less, and the content of bismuth in the aluminum alloy constituting the intermediate layer is 0.01% by mass. The method for producing a heat exchanger according to claim 6, wherein the content is 2.0% by mass or less.   The heat exchange according to claim 6 or 7, wherein each of the aluminum alloy constituting the first surface layer and the aluminum alloy constituting the second surface layer further contains 0.01 mass% or more and 1.0 mass% or less of bismuth. Manufacturing method. The first member constitutes at least a part of a space forming member that forms an internal space therein,
In the brazing step, the first member and a member to which the first member is joined are brazed and joined in a state in which the internal space of the space forming member and the external space of the space forming member are separated. The manufacturing method of the heat exchanger as described in any one of Claim 1 thru | or 8. A heat exchanger made of aluminum alloy,
A first member (11, 12, 13) constituting the heat exchanger;
A second member constituting the heat exchanger and joined to the first member;
A fillet (21, 22, 23, 24, 25, 26) formed at a brazed joint between the first member and the second member;
The fillet is a heat exchanger made of an aluminum alloy containing bismuth, magnesium, and silicon.

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