JP3689457B2 - Heat exchange tube element, heat exchanger having the heat exchange tube element, and method of manufacturing the heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger used in an air conditioner of an automobile, a method for manufacturing the heat exchanger, and a heat exchange tube element constituting the heat exchanger.
[0002]
[Prior art]
Conventionally, as this type of heat exchanger, the one disclosed in Japanese Patent Laid-Open No. 4-20794 has been proposed.
[0003]
In this heat exchanger, a pressed hole is formed in the projecting portion of one of the opposing molding plates, and a projection that fits into this hole is formed in the projecting portion of the other molding plate. Each forming plate is temporarily assembled and brazed.
[0004]
According to the manufacturing method of this heat exchanger, the portion between the hole and the projection also becomes a brazed portion, and the brazed portion expands, so even by applying the flux from the outside of the heat exchange tube element, Sufficient brazing strength can be obtained.
[0005]
[Problems to be solved by the invention]
However, in the conventional heat exchanger, a hole is formed on one side of the molding plate and a protrusion is formed on the other side, so that two different types of molding dies are required. It had the problem of causing an increase.
[0006]
Also, in this heat exchanger, air flows through the fins, but the adjacent fins are partitioned by heat exchange tube elements, so that air can flow between the fins. Absent. For this reason, the wind pressure of each fin may differ between fins depending on the wind direction, etc., but in such a situation, the amount of air passing between the fins varies and the problem is that uniform heat exchange cannot be achieved. Had a point.
[0007]
An object of the present invention is to provide a tube element for heat exchange that can be manufactured with a common molding plate in view of the above-mentioned conventional problems, and to improve heat exchange efficiency by using this tube element for heat exchange. It is another object of the present invention to provide a method of manufacturing a heat exchanger that improves brazing strength by using the heat exchange tube element.
[0008]
[Means for Solving the Problems]
According to the first and fourth aspects of the present invention, the protruding portion and the hole formed in the protruding portion are common to each facing wall, and each of the facing walls is formed by each molding plate. Can mold the molding plate in a common mold. Moreover, in the invention of claim 4, when the hole is made in the projecting portion, it is formed by simply penetrating a punch or the like without pressing, so that no chips are generated.
[0009]
According to the second and fifth aspects of the present invention, adjacent fins communicate with each other through holes formed in the opposing walls, so that air passing through the fin portions flows through the holes and the wind pressure of each fin portion is reduced. It becomes uniform.
[0010]
According to the invention of claim 3 and claim 6, since the joint portion of the protrusion is exposed to the outside through the hole, the flux and the brazing material wrap around the joint portion through this hole, and this joint portion is used as a brazing site. The In the invention of claim 6, since the overhanging portion is formed around the hole, the brazing material is accumulated in the overhanging portion, and the brazing strength is improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 to FIG. 17 show an embodiment of a heat exchange tube element, a heat exchanger and a heat exchanger manufacturing method to which the present invention is applied. FIG. 1 is used as a condenser for a vehicle air conditioner. FIG. 2 is a front view of a heat exchanger (hereinafter referred to as a second heat exchanger) used as an evaporator of a vehicle air conditioner.
[0012]
First, in the first heat exchanger 10 shown in FIG. 1, a plurality of heat exchange tube elements 12 (hereinafter referred to as tubes 12) penetrating through a pair of header pipes 11a and 11b facing left and right are vertically spaced. And a plurality of fins 13 for heat exchange are interposed between the tubes 12. In addition, a partition plate 11c is interposed in each of the header pipes 11a and 11b so that the refrigerant flowing in the heat exchanger 10 meanders.
[0013]
According to the first heat exchanger 10, as shown in FIG. 3, the discharged refrigerant flows from the compressor (not shown) through the refrigerant feeding pipe 14 of one header pipe 11a, meandering from above to downward. And is fed to an expansion valve (not shown) through the refrigerant outflow pipe 15 of the other header pipe 11b. Further, a heat exchange medium such as air passes through the fins 13, and heat is exchanged between the air and the refrigerant in the tube 12.
[0014]
On the other hand, the second heat exchanger 20 shown in FIG. 2 includes a tank 21 before and after the refrigerant branches or collects, a plurality of heat exchange tube elements 22 (hereinafter referred to as tubes 22) penetrating therethrough, and a heat exchange. And a plurality of fins 23 through which air flows. The tubes 22 and the fins 23 are alternately stacked. Moreover, this one tank 21 is divided into right and left by the partition 21a.
[0015]
According to the second heat exchanger 20, as shown in FIG. 4, the refrigerant depressurized by the expansion valve enters the suction part 21b of the front tank 21 through the refrigerant supply pipe 24 and faces the suction part 21b. Flows to the rear tank 21 through the tube 22 to be operated. The refrigerant further flows from the rear tank 21 to the tube 22 facing the outflow portion 21c, collects in the outflow portion 21c, and circulates to the compressor through the refrigerant outflow pipe 25. On the other hand, a heat exchange medium such as air passes through the fins 23, and heat is exchanged between the air and the refrigerant in the tube 22.
[0016]
The tubes 12 and 22 of the first heat exchanger 10 and the second heat exchanger 20 configured as described above are made of aluminum, aluminum alloy, or the like because of their workability and thermal conductivity. It is configured as shown in FIG.
[0017]
First, the tube 12 of the first heat exchanger 10 will be described with reference to FIG. As shown in FIG. 5 (a), the tube 12 has protrusions 12b symmetrically with respect to the center in the width direction of the flat plate 12a, and a hole 12c is formed at the center of the tip of the protrusion 12b. Yes. The flat plate 12a having the projecting portion 12b and the hole 12c is bent from the center in the width direction as shown by a one-dot chain line arrow in FIG. A tube 12 is formed.
[0018]
On the other hand, as shown in FIGS. 6A and 6B, the tube 22 of the second heat exchanger 20 has a pair of left and right forming plates 22a1 and 22a2, and the forming plates 22a1 and 22a2 have the same arrangement and A large number of protruding portions 22b having a shape are formed, and a hole 22c is formed at the center of the tip of the protruding portion 22b. The flat tubes 22 are formed by overlapping the molding plates 22a1 and 22a2 configured in this manner so that the protruding portions 22b are joined as shown in FIG.
[0019]
The protrusions 12b (22b) and the holes 12c (22c) of the first heat exchanger 10 and the second heat exchanger 20 configured as described above are common methods shown in FIGS. 8 (a), (b), and (c). Manufactured by.
[0020]
That is, as shown in FIG. 8A, the flat plate 12a or the molding plates 22a1 and 22a2 are placed between a lower mold 30 projecting upward and an upper mold 31 having a recess corresponding to the projecting portion. The plate 12a (22a1, 22a2) is arranged, the plate 12a (22a1, 22a2) is embossed, and a large number of protrusions 12b (22b) are formed.
[0021]
When this embossing is finished, the projecting portion 12b (22b) is positioned between the upper and lower molds 32, 33 having the punch through holes 32a, 33a, and then the punching punch 34 is disposed on the projecting portion 12b (22b). It is moved in the direction opposite to the protruding direction of, and penetrates and penetrates the protruding portion 12b (22b). Thereby, the hole 12c (22c) which has the overhang | projection part A is formed as shown in FIG.8 (c).
[0022]
When this drilling process is completed, the projecting height of the projecting portion 12b (22b) is somewhat lowered in this drilling process, so it is desirable to perform press working to correct this as shown in FIG. 8 (c). . That is, the protruding portion 12b (22b) is disposed between the upper mold 35 corresponding to the outer surface of the protruding portion 12b (22b) and the lower mold 36 that pushes up the inner side of the protruding portion 12b (22b) and pressed. Thereby, the protrusion height of the protrusion part 12b (22b) is correct | amended to a desired dimension. Note that this correction press work is not necessary in the embossing or the like when setting a projection height or the like that takes this correction value into consideration in advance.
[0023]
In this way, the tube 12 (22) is formed. The components of the heat exchanger 10 (20) including the tube 12 (22) are temporarily assembled and then brazed. During the temporary assembly process, first, the temporary assembly process of the first heat exchanger 10 will be described with reference to FIGS. 9 and 10.
[0024]
First, a temporary assembling jig for temporarily assembling the first heat exchanger 10 is prepared. This temporary assembling jig has a support bar 50 extending vertically, and a fixed tongue piece 51 is fixed near the lower end of the support bar 50, and a movable penetrating through the support bar 50 near the upper end and movable up and down. A tongue piece 52 is attached. Two such support rods 50 are prepared, and in addition to the support rod 50, two horizontally long rectangular tubular contact members 53 are prepared as temporary assembly jigs.
[0025]
On the other hand, on the heat exchanger 10 side, a plurality of tubes 12 are arranged at intervals between the header pipes 11a and 11b facing left and right, and both ends of each tube 12 are inserted into the header pipes 11a and 11b and temporarily fixed. . Further, a reinforcing side plate 16 is disposed above the tube 12 positioned at the uppermost portion and below the tube positioned at the lowermost portion of the tube 12 so as to be spaced from the tube 12. Both ends of 16 are similarly inserted into the header pipes 11a and 11b and temporarily fixed. When the temporary fixing of the tubes 12 and the side plates 16 is completed, the fins 13 are interposed between the tubes 12 adjacent to each other in the vertical direction and between the tubes 12 and the side plates 16. Note that the upper and lower caps 11d, the partition plate 11c, the refrigerant supply pipe 14, and the refrigerant outflow pipe 15 of the header pipes 11a and 11b are temporarily fixed to the header pipes 11a and 11b, respectively.
[0026]
When such a temporary assembly jig and the temporarily assembled first heat exchanger 10 are prepared, first, the contact members 53 are fitted into the upper and lower side plates 16 of the first heat exchanger 10, respectively. Next, the support rods 50 are arranged on the left and right sides so that both ends of the first heat exchanger 10 can be supported, and the first heat exchanger 10 is placed on the fixed tongue piece 51 of the support rod 50 via the contact member 53. . Thereby, the temporarily assembled first heat exchanger 10 is supported on the support rod 50. After that, as shown in FIG. 9, the movable tongue piece 52 is shifted downward to hold the first heat exchanger 10 between the movable tongue piece 52 and the fixed tongue piece 51. Thereby, the temporarily assembled first heat exchanger 10 is fixed by the temporary assembly jig as shown in FIG.
[0027]
Next, the temporary assembly process of the second heat exchanger 20 will be described with reference to FIGS.
[0028]
First, a temporary assembly jig for temporarily assembling the second heat exchanger 20 is prepared. This temporary assembling jig has a rectangular support frame 61 in which a pair of parallel connecting rods 65 extend to the left and right and front and back, and both ends thereof are connected by prismatic fixing brackets 62 and 64, respectively. A female screw is engraved in the center of the one fixing metal 64, and a T-bolt 63 is screwed into the female screw. As shown in FIG. 12, the T-shaped bolt 63 penetrates in a state where the shaft portion 63 a is screwed to the fixing bracket 64, while the tip of the shaft portion 63 a is flat. Is rotated in the left-right direction as indicated by arrows in FIG. Two such support frames 61 are prepared on the top and the bottom, and two vertically long bracket-shaped presser plates 60 are prepared as temporary assembly jigs in addition to the support frame 61.
[0029]
On the other hand, in the second heat exchanger 20, a plurality of tubes 22 are arranged at intervals on the left and right sides, and tanks 21 are arranged at the upper and lower ends of the tubes 22 so that the tubes 22 and the tanks 21 are in communication with each other. Temporarily fix. Further, side plates 26 are disposed on both the left and right sides of the tube 22, and fins 23 are interposed between the adjacent tubes 22 and between the tube 22 and the side plate 26. When the fins 23 are interposed, the molded plates 22a1 and 22a2 of the tube 22 have bent portions 22d1 and 22d2, and the bent portions 22d1 and 22d2 prevent the fins 23 from dropping between the tubes 22. ing. The partition plate 21a, the refrigerant supply pipe 24, and the refrigerant outflow pipe 25 are temporarily fixed to the tank 21 in advance.
[0030]
When such a temporarily assembled jig and the temporarily assembled second heat exchanger 20 are prepared, the T-bolts 63 of the two support frames 61 are rotated to temporarily mount the second heat exchanger. 20 storage space is taken up. Next, the two support frames 61 are arranged vertically at the approximate center of the second heat exchanger 20, and the second heat exchanger 20 is accommodated in the support frame 61. Then, the presser plate 60 is inserted between the side plate 26 of the second heat exchanger 20 and the fixing brackets 62 and 64. Thereafter, the T-shaped bolt 63 is rotated to hold the second heat exchanger 20 between the two presser plates 60. Thereby, the temporary assembly of the second heat exchanger 20 is completed as shown in FIG.
[0031]
When such temporary assembly of the first heat exchanger 10 and the second heat exchanger 20 is completed, the process proceeds to a common brazing process shown in FIGS. 14 (a) and 14 (b).
[0032]
That is, in this brazing process, first, a non-corrosive flux 40 is applied from the outside of the heat exchanger 10 (20) including the tubes 12 (22) and the fins 13 (23) as shown in FIG. To do.
[0033]
As a method of applying the flux, a method of applying a 4% to 10% flux aqueous solution or an alcohol solution by spraying, a method of electrostatically applying a powdery flux, or charging the heat exchanger 10 (20). There is a method of simply applying powdery flux, but from the meaning of omitting the drying process and subsequent brazing conditions, the method of electrostatically applying powdery flux or powder without charging A method of applying a body-like flux is desirable.
[0034]
When such a flux application process is completed, the temporarily assembled heat exchanger 10 (20) is brazed in an inert gas. As a result, the butted portion of the projecting portion 12b (22b) is brazed, but as shown in FIG. 14 (b), the fillet 41 is formed on the periphery of the butted portion, particularly on the protruding portion A of the hole 12c (22c). A large amount is formed in the part.
[0035]
As described above, according to the present embodiment, in the tube 12 (22), the hole 12c (22c) formed at the time of manufacture is not subjected to press shear, and the punching punch 34 is simply provided with the protrusion 12b (22b). Since it is formed by breaking through, no chips are generated and no air mechanism is required.
[0036]
Further, since the projecting portions 22b and the holes 22c of the molding plates 22a1 and 22a2 constituting the tube 22 have the same arrangement and shape, the molding plates 22a1 and 22a2 can be used in common, and the molding is simplified.
[0037]
In the heat exchanger 10 (20) configured using the tube 12 (22), air passing through the adjacent fins 13 (23) with the tube 12 (22) in between flows through the holes 12c (22c). The wind pressure at each fin 13 (23) becomes uniform.
[0038]
In the manufacturing method of the heat exchanger 10 (20) configured by using the tube 12 (22), the flux 40 is applied to the abutting portion of the protruding portion 12b (22b) through the hole 12c (22c), and the brazed portion. In addition, since the fillet 41 is formed in a large amount in the overhanging portion A, a sufficient brazing strength can be ensured without applying the flux 40 inside the tube 12 (22).
[0039]
Further, since the butted portion of the projecting portion 12b (22b) is securely brazed in this way, the strength of the tube 12 (22) is improved, and damage due to the refrigerant pressure does not occur. Even when the butt portion of the portion 12b (22b) is not securely brazed, the butt portion with poor bonding can be reliably found by the prior leakage inspection.
[0040]
In the above-described embodiment, the protrusion 22b is formed in a circular shape. However, as shown in FIG. 15A, the protrusion 22b may be formed in a long groove-like protrusion 22b1 or a triangular protrusion 22b2. In addition, a plurality of holes 22c may be provided. Further, as shown in FIG. 15 (b), a long groove-like projecting portion 22b1 may be constituted by a long hole 22c1 that breaks along the groove, and further, a partition for the forming plate 22a1 (22a2). You may make it form the protrusion part 22b and the hole 22c in the part 22d.
[0041]
Further, in the embodiment of the first heat exchanger 10, the flat plate 12a is bent to form the flat tube 12. However, as shown in FIG. 16, two flat plates having a protruding portion 12b and a hole 12c are formed. Plates 12d1, 12d2 may be formed, and the flat plates 12d1, 12d2 may be bonded to each other and brazed. Further, in the embodiment of the second heat exchanger 20, a pair of molded plates 22a1 and 22a2 are prepared in advance and are joined to face each other to form the tube 22. However, as shown in FIG. Further, the forming plates 22a1 and 22a2 having the holes 22c may be connected and formed, the connecting portions may be bent and the forming plates 22a1 and 22a2 may be overlapped to form the tube 22.
[0042]
FIGS. 18 (a) and 18 (b) and FIGS. 19 (a) and 19 (b) show other embodiments of the present invention. The tube 72 according to this embodiment has a pair of left and right forming plates 72a1 and 72a2 formed with protrusions 72b and holes 72c formed in the protrusions 72b in the same manner as the tube 22. As shown in FIGS. 18A and 18B, the tip 72b1 of the protrusion 72b is formed flat, and the hole 72c formed in the flat tip 72b1 is formed flush with the tip 72b1. Different from the tube 22.
[0043]
When manufacturing such protrusions 72b and holes 72c, as shown in FIG. 19A, as in the case of the tube 22, as shown in FIG. 19A, the molding plates 72a1 and 72a2 A molding plate 72a1 (72a2) is disposed between the lower mold 30 projecting upward and the upper mold 31 formed with a recess so as to correspond to the projecting portion, and the molding plate 72a1 (22a2) is embossed to form a tip 72b1. A large number of flat protrusions 72b are formed.
[0044]
When this embossing is completed, the projecting portion 72b is positioned between the upper and lower molds 32, 33, and then the press punch 37 is passed through the center of the tip 72b1 of the projecting portion 72b to perform drilling. Thereby, a tube 72 as shown in FIGS. 18A and 18B is manufactured.
[0045]
According to the present embodiment, it is not possible to prevent the generation of chips as in the previous embodiment, but the manufacturing process is very simple, and it is applied to the outer surfaces of the molding plates 72a1 and 72a2. As shown in FIG. 18 (a), the flux A thus formed also wraps around the inside of the hole 72c, and after brazing in an inert gas, a large amount of fillet 41 is formed at the butt portion. It has high attachment strength.
[0046]
In this embodiment, the adhesion amount of the flux 40 is 3 g / m ³ or more. Moreover, the tube 72 according to the present embodiment is temporarily assembled as the second heat exchanger 20 in the same manner as the tube 22 and brazed in the same manner.
[0047]
【The invention's effect】
As described above, according to the first and fourth aspects of the invention, the protruding portion and the hole formed in the protruding portion are common to each opposing wall, and When the molding plate is configured, the molding plate can be molded with a common mold, so that the manufacturing cost is reduced. Further, in the invention of claim 4, when forming a hole in the projecting portion, it is formed by simply breaking through without pressing, so that an air mechanism for blowing off the chips as in the past is installed without generating chips. Is not required.
[0048]
According to invention of Claim 2 and Claim 5, since it communicates with each adjacent fin through the hole formed in the opposing wall, the air which passes through a fin part mutually distribute | circulates through this hole, and the wind pressure of each fin part is carried out. The heat exchange efficiency of the entire heat exchanger can be improved.
[0049]
According to the third and sixth aspects of the present invention, since the joint portion of the protrusion is exposed to the outside through the hole, the joint portion can be used as a brazing portion, and the brazing portion is enlarged. Further, in the invention of claim 6, since the overhanging portion is formed around the hole, the brazing material is accumulated in the overhanging portion, and the brazing strength is improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first heat exchanger. FIG. 2 is a perspective view of a second heat exchanger. FIG. 3 is an explanatory diagram showing a refrigerant flow in the first heat exchanger. FIG. 5 is a perspective view of the heat exchange tube element of the first heat exchanger. FIG. 6 is a front view of the heat exchange tube element of the second heat exchanger. FIG. 8 is a cross-sectional view showing the manufacturing process of the protrusion and the hole. FIG. 9 is a perspective view showing a temporary assembly jig used for the temporary assembly of the first heat exchanger. FIG. 10 is a perspective view showing a state where the first heat exchanger is held by a temporary assembly jig. FIG. 11 is a perspective view showing a temporary assembly jig used for the temporary assembly of the second heat exchanger. FIG. 12 is a partially cutaway plan view of the temporary assembly jig of the second heat exchanger. FIG. 13 is a perspective view showing a state in which the second heat exchanger is held by the temporary assembly jig. FIG. 15 is an abbreviated front view showing a modification of the protrusion and the hole. FIG. 16 is a perspective view showing another manufacturing process of the tube of the first heat exchanger. 17 is a front view showing another manufacturing process of the tube of the second heat exchanger. FIG. 18 is a cross-sectional view showing a flux application process and a brazing process according to another embodiment. FIG. 19 is related to another embodiment. Sectional drawing showing manufacturing process of protrusion and hole 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 10,20 ... Heat exchanger, 12, 22, 72 ... Tube element for heat exchange, 12a ... Flat plate, 12b, 22b, 72b ... Projection part, 12c, 22c, 72c ... Hole, 13, 23 ... Fin, 34 ... Hole punch, 40 ... flux, A ... overhang.

Claims (6)

In the tube element for heat exchange formed in a flat tube, forming a large number of projecting portions toward the facing surface on the facing wall, and abutting and joining the tips of the facing projecting portions,
The tip of the flat tubes each projecting portion two molding plates to form superposed to abut respective protrusions facing the respective molding plate is the same arrangement and shapes, said each projection A tube element for heat exchange, characterized in that the tip of the part is flat and has holes of the same arrangement and shape . 2. A heat exchanger according to claim 1, wherein the heat exchange tube elements of claim 1 through which the refrigerant passes and the heat exchange fins through which a medium such as air passes are alternately stacked. The heat exchange tube element and the fin of claim 2 are temporarily assembled, and then the non-corrosive flux is applied only from the outside of the heat exchange tube element and the fin, and then brazed in an inert gas. A method for manufacturing a heat exchanger. In the tube element for heat exchange formed in a flat tube, forming a large number of projecting portions toward the facing surface on the facing wall, and abutting and joining the tips of the facing projecting portions,
The tube element for heat exchange characterized by having the hole which penetrated in the direction opposite to the protrusion direction at the front-end | tip of each said protrusion part, and formed the overhang | projection part. The heat exchanger according to claim 4, wherein the heat exchange tube elements according to claim 4 and the heat exchange fins through which a medium such as air passes are alternately stacked. The tube elements and fins for heat exchange according to claim 5 are alternately stacked and temporarily assembled, and then a non-corrosive flux is applied from the outside of the tube elements and fins for heat exchange, and then in an inert gas. A method of manufacturing a heat exchanger, characterized by being brazed.

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