JP6182876B2 - Tube for heat exchanger and method for producing heat exchanger - Google Patents

Description

The present invention relates to a heat exchanger tube mounted on a heat exchanger and a method for manufacturing the heat exchanger .

  2. Description of the Related Art Conventionally, aluminum heat exchanger tubes (hereinafter also simply referred to as tubes) have been proposed in which inner column portions for increasing the pressure resistance of the tubes are provided inside the tubes (for example, Patent Documents). 1). Such a tube is formed by brazing and joining the width direction (bending direction) both ends of the metal plate bent into the flat tube shape.

JP 2005-510688 A

  In general, when a fluid containing water as a main component is circulated in a tube, a sacrificial material layer to which Zn is added is clad on the inner surface of the tube (a surface in contact with the fluid). Further, a brazing filler metal layer to which Si is added is clad on the outer surface of the tube for joining to the outer fin and joining the inner pillar portion. That is, the tube has a three-layer structure having a sacrificial material layer, a core material, and a brazing material layer.

  By the way, when the thickness of the tube is reduced, the thickness of the tube is reduced, so that the strength is reduced, and the durability is lowered. On the other hand, in order to improve the durability of the tube, a method of increasing the strength by adding Mg to aluminum constituting the core material can be considered. At that time, the strength of the tube can be further improved by adding Mg not only to the core material but also to the sacrificial material.

  However, since Mg inhibits the spread of the flux that removes the oxide film during brazing of aluminum, the brazing property may be deteriorated. In particular, in the tube having the inner pillar portion as described above, it is necessary to braze the joint portion between the tube inner surface and the inner pillar portion, that is, the contact portion between the sacrificial material layer and the brazing material layer. There is a problem that Mg added to the steel deteriorates brazeability.

  In view of the above points, an object of the present invention is to suppress deterioration of brazing properties with a member to be joined in a heat exchanger tube containing a material that deteriorates brazing properties.

In order to achieve the above object, according to the first aspect of the present invention, a fluid circulates in the interior and is made of a folded plate (200), and the plate has a core (201) made of aluminum or an aluminum alloy. A heat exchanger tube, a tube main body (21), and a member to be joined (22, 8) brazed to the tube main body with a brazing material (202, 802) coated with a flux (300); And a sacrificial material layer (203) clad with a sacrificial material containing a reactive material that reacts with the flux and having a lower potential than the core material is formed on the surface of the tube main body, A brazing surface constituent part (21a) for joining the tube main body part and the member to be joined is formed in a part of the main body part, and a portion corresponding to the brazing surface constituent part in the sacrificial material layer , A material other than the brazing material, and the reaction dressing constructed of a material other than the material (400) is covered by the covering material (400) is not included pure aluminum or reactive materials aluminum It is characterized by being made of an alloy .
According to a fourth aspect of the present invention, there is provided a heat exchanger manufacturing method in which a tube body portion and a member to be joined are brazed on the brazed joint surface, wherein a sacrificial material is clad in a plate material. A step of coating a covering material (400) made of a material other than the reaction material on a portion to be a brazed joint surface of the surface of the tube, bending the plate material coated with the covering material, and the tube main body portion and the bonded portion A step of forming a tube so as to contact the material , a step of temporarily fixing a plurality of formed tubes to a core plate, and a temporarily assembled body in which the plurality of tubes and the core plate are temporarily fixed in a heating furnace. And a step of heating and brazing.

  According to this, the brazing surface constituting part (21a) made of a material containing a reaction material that reacts with the flux (300) is covered with the covering material (400) made of a material other than the reaction material. That is, by disposing the covering material (400) between the flux (300) and the brazing surface constituting portion (21a), the reaction material is coated from the brazing surface constituting portion (21a) during brazing. Is diffused to (400). Therefore, since it can suppress that the reaction material from a brazing surface structure part (21a) diffuses into a flux (300), it can suppress that a reaction material and a flux (300) react and brazing property deteriorates. .

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a front view which shows the radiator in 1st this embodiment. It is sectional drawing which shows the cross section orthogonal to the cooling water flow direction of the tube which concerns on 1st Embodiment. It is the III section enlarged view of FIG. It is a schematic diagram which shows the manufacturing apparatus of the tube in 1st Embodiment. It is sectional drawing which shows the cross section orthogonal to the cooling water flow direction of the tube which concerns on 2nd Embodiment. FIG. 6 is an enlarged view of a part VI in FIG. 5. It is sectional drawing which shows the cross section orthogonal to the cooling water flow direction of the tube which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the heat exchanger tube according to the present invention is applied to the tube 2 of the radiator 1 for exchanging heat between the engine cooling water that has cooled the vehicle engine (internal combustion engine) and the air.

  In FIG. 1, a tube 2 is a tube through which engine cooling water flows. The tube 2 is formed in a flat shape so that the air flow direction (perpendicular to the paper surface) coincides with the major axis direction, and the longitudinal direction thereof. Are arranged in parallel in the vertical direction so as to coincide with the horizontal direction.

  Further, wave-shaped outer fins 3 are joined to the flat surfaces on both sides of the tube 2, and the heat transfer area between the engine cooling water and the air is increased by increasing the heat transfer area with the air by the outer fins 3. Promoting. Hereinafter, the substantially rectangular heat exchanging portion including the tube 2 and the outer fin 3 is referred to as a core portion 4.

  The header tank 5 extends in a direction (vertical direction in the present embodiment) perpendicular to the longitudinal direction of the tube 2 at a longitudinal end portion (in the present embodiment, left and right ends) of the tube 2. It communicates. The header tank 5 includes a core plate 5a to which the tube 2 is inserted and joined, and a tank body 5b that constitutes a tank internal space together with the core plate 5a. In the present embodiment, the core plate 5a is made of metal (for example, aluminum alloy), and the tank body 5b is made of resin.

  A concave groove (not shown) is provided on the entire periphery of the edge of the core plate 5a. A packing (not shown) made of an elastic material such as rubber is disposed in the groove, and the gap between the tank body 5b and the core plate 5a is liquid-tightly sealed by this packing. A claw portion (not shown) is erected on the peripheral edge of the core plate 5a, and the tank main body 5b is fixed to the flange formed on the outer peripheral edge of the tank main body 5b. 5a is assembled.

  At both ends of the core part 4, inserts 6 that extend substantially in parallel with the longitudinal direction of the tube 2 and reinforce the core part 4 are provided.

  Next, the shape of the tube 2 that is a characteristic point of the present embodiment will be described with reference to FIGS. 2 and 3.

  As shown in FIG. 2, the tube 2 has a tube main body 21 that forms a cooling water channel (fluid channel) 20 through which cooling water flows. Inside the tube main body portion 21, an inner column portion 22 is provided so as to connect the two flat surfaces and increase the pressure resistance of the tube main body portion 21. The inner column portion 22 is disposed in the center portion in the air flow direction inside the tube main body portion 21. The inner column portion 22 divides the cooling water flow path 20 inside the tube main body portion 21 into two.

  The tube main body portion 21 and the inner column portion 22 are integrally formed by bending a plate-like member 200 made of aluminum alloy. Specifically, the portions in the vicinity of both ends of the plate-like member 200 are bent substantially at right angles so as to protrude toward the tube inner surface 11 side as the back surface of the plate-like member 200 continuously in the longitudinal direction intersecting the width direction. Thereby, the 1st brazing part 12 is formed.

  By bending the inner side of the first brazing portion 12 in the plate-like member 200 continuously in the longitudinal direction intersecting the width direction so as to protrude toward the tube inner surface 11 as the back surface of the plate-like member 200, The 2nd brazing part 13 is formed. In the cross section perpendicular to the longitudinal direction of the tube 2 (circulation direction of the cooling water), the length of the second brazing part 13 is longer than the length of the first brazing part 12, and the height of the cooling water flow path 20 is high. Is approximately equal to Hi. The height Hi of the cooling water channel 20 is the length of the cooling water channel 20 in the tube stacking direction.

  Then, the tube 2 is bent so that the inner side of the second brazing portion 13 in the plate-shaped member 200 is bent toward the tube inner surface 11 side, that is, with the opposite tube outer surface 14 side being the outer side. The surface on the side (tube outer surface 14 side) is in contact with the surface on the back surface side (tube inner surface 11 side) of the central portion in the width direction of the plate-like member 200 in the longitudinal direction, and the surface side of the second brazed portion 13 ( The surfaces on the tube outer surface 14 side) are formed so as to contact each other over the longitudinal direction.

  Thereby, the inner pillar portion 22 is formed by the first brazing portion 12 and the second brazing portion 13. Further, the tube main body portion 21 is formed by a portion other than the first brazing portion 12 and the second brazing portion 13 in the plate-like member 200.

  By brazing the first brazing part 12 to the plate-like member 200, the inner column part 22 is brazed and joined to the tube main body part 21. Therefore, the inner column part 22 (more specifically, the first brazing part 12) of the present embodiment corresponds to the member to be joined of the present invention.

  As shown in FIG. 3, the plate-like member 200 has a core material 201 made of an aluminum alloy. In this embodiment, specifically, an aluminum-magnesium (Al—Mg) alloy is employed as the core material 201.

  A brazing material 202 for brazing the outer fin 3, the first brazing part 12, and the second brazing part 13 is clad on the surface (tube outer surface 14) of the core material 201. In the present embodiment, specifically, an aluminum-silicon (Al—Si) brazing material is employed as the brazing material 202.

  A sacrificial material 203 made of a material having a lower potential than the core material 201 is clad on the back surface (tube inner surface 11) of the core material 201. The sacrificial material 203 functions to suppress corrosion of the core material 201 by preferentially corroding the core material 201. In the present embodiment, specifically, an aluminum-zinc-magnesium (Al—Zn—Mg) alloy is employed as the sacrificial material 203.

  A flux 300 for chemically removing an oxide film on the brazed joint surface is applied to the brazed joint surface between the tube main body portion 21 and the first brazed portion 12 in the plate member 200.

  As described above, Mg is added to the aluminum alloy, which is a constituent material of the core material 201 and the sacrificial material 203, in order to increase the strength of the tube 2. Here, Mg is a material that is not contained in the brazing filler metal 202 and reacts with the flux 300. Therefore, Mg of this embodiment is equivalent to the reaction material of a claim.

  As described above, since Mg is added to the constituent material of the core material 201 and the sacrificial material 203, the portion constituting the joint surface with the first brazing portion 12 in the tube main body portion 21 (hereinafter referred to as brazing surface configuration). It can be said that the portion 21a is made of an aluminum alloy material containing Mg. In the present embodiment, the brazing surface constituting portion 21 a is disposed at a substantially central portion in the width direction of the plate-like member 200.

  The brazing surface constituting part 21a of the tube main body part 21 is covered with a coating material 400 as a covering material made of a material other than Mg. In the present embodiment, pure aluminum is employed as the coating material 400.

  Next, the manufacturing method of the tube 2 of this embodiment is demonstrated. As shown in FIG. 4, the tube manufacturing apparatus includes a material roll 71, a coating apparatus 72, a forming apparatus 73, and the like.

  The material roll 71 is obtained by winding a plate member 200 that is a tube material. The coating device 72 applies the coating material 400 to the central portion in the width direction of the plate-like member 200 taken out from the material roll 71.

  The molding device 73 performs plastic working on the plate member 200 with a plurality of molding rollers 730 while feeding the plate member 200 coated with the coating material 400 by the coating device 72 in the longitudinal direction thereof. The plate member 200 is gradually formed into a predetermined shape. Specifically, the tube main body portion 21 and the inner column portion 22 are integrally formed by bending the plate-like member 200 as described above.

  Next, a method for manufacturing the radiator 1 according to this embodiment will be described.

  First, a plurality of tubes 2 manufactured by the above-described method, a core plate 5a in which a brazing material is clad on the outer surface of the tank, that is, the surface facing the core portion 4, the outer fin 3, and the insert 6 are provided. prepare.

  Next, after the outer fins 3 are loaded between the plurality of tubes 2 arranged at predetermined intervals and the core portion 4 is temporarily assembled, through holes (not shown) formed in the core plate 5a of the header tank 5 are shown. 1) Each tube 2 and insert 6 are inserted into the inside. Thereby, temporary fixing (temporary assembly) of the core plate 5a of the header tank 5, each tube 2, the outer fin 3, and the insert 6 is completed.

  Next, this temporary assembly is carried into a heating furnace, and the core portion 4 (that is, the tube 2 and the outer fin 3), the insert 6 and the core plate 5a are integrally joined by brazing. More specifically, by heating the temporary assembly in a heating furnace, the tube 2 and the insert 6 are brazed and joined to the core plate 5a by the brazing material clad on the core plate 5a, and the surface of the tube 2 The outer fin 3 is brazed and joined to the outer surface of the tube 2 by the brazing material 202 clad.

  At this time, the first brazing portion 12 of the inner column portion 22 is brazed and joined to the tube main body portion 21 by the brazing material 202 clad on the surface of the tube 2, and the second brazing facing the inner column portion 22. The parts 13 are brazed and joined.

  Next, the tank body 5b is assembled to the core plate 5a. In this way, the radiator 1 shown in FIG. 1 is completed.

  As described above, in this embodiment, Mg is added to the core material 201 and the sacrificial material 203 of the plate-like member 200 constituting the tube 2. For this reason, since the strength of the tube 2 can be increased, the durability of the tube 2 can be improved. On the other hand, Mg reacts with the flux 300 at the time of brazing, obstructs the spreadability of the flux 300, and may deteriorate the brazing property.

  On the other hand, in this embodiment, the brazing surface constituting portion 21a (sacrificial material 203) made of an aluminum alloy containing Mg is covered with a coating material 400 made of pure aluminum not containing Mg. Yes. That is, the coating material 400 is arrange | positioned between the flux 300 and the brazing surface structure part 21a. According to this, since Mg from the brazing surface constituting portion 21 a is diffused into the coating material 400 when the plate-like member 200 is brazed, it is possible to prevent Mg from diffusing into the flux 300. Therefore, it can suppress that Mg and the flux 300 react and brazing property deteriorates.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that the inner fin 8 is provided inside the tube main body 21.

  As shown in FIG. 5, the tube 2 of the present embodiment includes a tube main body portion 21 and inner fins 8 that are provided in the tube main body portion 21 and increase the heat transfer area with cooling water. Yes. The tube main body 21 and the inner fin 8 are composed of different plate-like members 200 and 800, respectively. Here, as the plate-like member 800 constituting the inner fin 8, for example, an aluminum alloy can be used.

  The tube main body portion 21 of the present embodiment includes a first flat plate portion 211 and a second flat plate portion 212 that face each other in parallel in the short diameter direction, and a circular arc that protrudes outward on one end side (left side of the paper surface) in the long diameter direction. It comprises an arcuate curved portion 213 and a caulking portion 214 for caulking and joining the first and second flat plate portions 211 and 212 on the other end side in the major axis direction (right side in the drawing). The arcuate curved portion 213 is bent integrally with the first and second flat plate portions 211 and 212, and connects the first and second flat plate portions 211 and 212.

  A fin-side flat plate portion 81 formed in a flat plate shape parallel to the first and second flat plate portions 211 and 212 is provided on the caulking portion 214 side of the inner fin 8. The fin-side flat plate portion 81 is wound together with the second flat plate portion 212 by the first flat plate portion 211 while being sandwiched between the first and second flat plate portions 211 and 212 of the tube main body portion 21.

  Here, the winding caulking means that one of the first and second flat plate portions 211 and 212 of the tube main body portion 21 (the first flat plate portion 211 in this embodiment) is replaced with the other flat plate portion (this embodiment). In the embodiment, both the flat plate portions 211 and 212 are mechanically fixed by plastically deforming the flat plate portion on one side so as to be wound around the second flat plate portion 212).

  The portion of the inner fin 8 excluding the fin-side flat plate portion 81 is formed in a wave shape so as to have a flat portion 82 that is substantially parallel to the cooling water flow direction and a top portion 83 that connects between the adjacent flat portions 82. . And the top part 83 is formed so that the 1st, 2nd flat plate parts 211 and 212 of the tube main-body part 21 may be contact | connected.

  The inner fin 8 is brazed and joined to the tube main body 21 by brazing the top 83 of the inner fin 8 to the first and second flat plate portions 211 and 212 of the tube main body 21. Therefore, the inner fin 8 of this embodiment is equivalent to the to-be-joined member of this invention.

  As shown in FIG. 6, the plate-like member 800 constituting the inner fin 8 has a core material 801 made of aluminum alloy. In this embodiment, specifically, an aluminum-magnesium (Al-Mg) alloy is employed as the core material 801.

  A brazing material 802 for brazing the tube main body 21 is clad on both surfaces of the core material 801. In the present embodiment, specifically, an aluminum-silicon (Al—Si) brazing material is employed as the brazing material 802.

  A flux 300 that chemically removes an oxide film on the brazed joint surface is applied to the brazed joint surface between the tube main body 21 and the inner fin 8.

  As described above, since Mg is added to the constituent material of the core member 201 and the sacrificial member 203 of the plate-like member 200, the portion constituting the joint surface with the inner fin 8 in the tube main body portion 21 (hereinafter referred to as brazing). It can be said that the surface constituting portion 21a is made of an aluminum alloy material containing Mg.

  As described above, in the present embodiment, the brazing surface constituting portion 21a made of an aluminum alloy containing Mg is covered with the coating material 400 made of pure aluminum not containing Mg. According to this, since Mg from the brazing surface constituting portion 21 a is diffused into the coating material 400 when the plate-like member 200 is brazed, it is possible to prevent Mg from diffusing into the flux 300. Therefore, the same effect as the first embodiment can be obtained.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

  (1) In the said 1st Embodiment, the tube 2 in which the inner pillar part 22 was provided in the inside of the tube main-body part 21 was formed by bending the plate-shaped member 200 toward the tube inner surface 11 side from both ends. However, the method of forming the tube 2 is not limited to this. For example, as shown in FIG. 7, a protrusion 24 is bent at the center in the width direction of the plate-like member 200, the opposing inner surfaces of the protrusion 24 are brazed and joined, and the thickness direction of the protrusion 24 (plate-like) The tube 2 may be formed by brazing and joining the width direction both ends 25 of the plate-like member 200 to the side portion of the member 200 in the width direction.

  At this time, the inner pillar portion 22 is formed by the protrusion 24 and the width direction both ends 25 of the plate member 200 brazed to the protrusion 24. Moreover, the site | part which comprises the joining surface with the inner pillar part 22 in the tube main-body part 21, ie, the width direction both ends 25 of the plate-shaped member 200 comprises the brazing surface structure part 21a.

  (2) In the above embodiment, an example in which pure aluminum is used as the coating material 400 has been described. However, the present invention is not limited to this, and an aluminum alloy not containing Mg or a brazing material not containing Mg is used. May be.

  (3) In the above embodiment, in order to increase the strength of the tube 2, Mg, which is a reactive material that reacts with the flux 300, is added to the core material 201 and the sacrificial material 203 of the plate-like member 200 constituting the tube 2. However, the present invention is not limited to this. For example, at least one of Ti and Mn may be added to the core material 201 and the sacrificial material 203 of the plate-like member 200 constituting the tube 2.

  Here, since Ti and Mn are flow-inhibiting materials that inhibit the flow of the brazing filler metal 202 that has melted during brazing, if Ti or Mn diffuses into the brazing filler metal 202, brazing properties may deteriorate.

  On the other hand, by covering the brazing surface constituting portion 21a made of an aluminum alloy containing at least one of Ti and Mn with a coating material 400 made of a material not containing Ti and Mn, a plate shape When the member 200 is brazed, Ti and Mn are diffused from the brazing surface constituting portion 21 a into the coating material 400. Therefore, since Ti and Mn can be prevented from diffusing into the brazing material 202, it is possible to inhibit the flow of the molten brazing material 202 from being inhibited and the brazing performance from deteriorating.

  In this case, as the coating material 400, pure aluminum, an aluminum alloy that does not contain Ti and Mn, or a brazing material that does not contain Ti and Mn can be employed.

21 Tube body portion 21a Brazing surface constituting portion 22 Inner column portion (member to be joined)
201 Core material 202 Brazing material 300 Flux 400 Coating material (coating material)

Claims (4)

A fluid flows through the inside and is made of a bent plate (200), the plate being a heat exchanger tube having a core (201) made of aluminum or an aluminum alloy,
A tube body (21);
A member to be joined (22, 8) to be brazed to the tube main body with a brazing material (202, 802) coated with a flux (300);
A sacrificial material layer (203) that contains a reactive material that reacts with the flux and is clad with a sacrificial material that has a lower potential than the core material is formed on the surface of the tube main body,
A brazing surface constituting part (21a) for joining the tube body part and the member to be joined is formed on a part of the tube body part,
Of the sacrificial material layer, a portion corresponding to the brazing surface constituting portion is covered with a covering material (400) made of a material other than the brazing material and made of a material other than the reaction material. And
The said covering material (400) is comprised with the aluminum alloy which does not contain the pure aluminum or the said reaction material, The tube for heat exchangers characterized by the above-mentioned . The tube main body (21) is constituted by a bent plate-like member (200), and an inner column (22) for dividing the fluid flow path (20) in the tube main body (21) into a plurality of parts. Have
It said portion constituting pillar portion (22) is a heat exchanger tube of claim 1, wherein a bonded members of the plate member (200). The tube body (21) is constituted by a folded plate-like member (200),
The said covering material (400) is arrange | positioned only in the width direction center part of the said plate-shaped member (200) in the said tube main-body part (21), The heat | fever of Claim 1 or 2 characterized by the above-mentioned. Tube for exchanger. A fluid flows through the inside, and has a plurality of tubes (2) arranged in a stacked manner, and a core plate (5a) in which ends of the plurality of tubes are inserted and joined,
The tube
Formed by bending a plate (200) having a core (201) made of aluminum or an aluminum alloy,
A flux (300) for chemically removing an oxide film formed on the brazed joint surface between the tube main body (21) and the members to be joined (22, 8) is applied to the brazed joint surface,
A sacrificial material (203) containing a reactive material that reacts with the flux on one surface of the core material and having a lower potential than the core material is clad,
A method of manufacturing a heat exchanger in which the tube main body and the member to be joined are brazed on the brazed joint surface,
Coating the covering material (400) made of a material other than the reaction material on a portion of the one surface where the sacrificial material is clad in the plate material to be the brazing joint surface;
A step of the dressing bending the plate coated, molding the tube such as the tube body portion and the bonding portion member is in contact,
Temporarily fixing the plurality of molded tubes to the core plate;
A method of manufacturing a heat exchanger, comprising: heating and brazing a temporarily assembled body in which a plurality of tubes and the core plate are temporarily fixed in a heating furnace.

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