METHOD FOR PRODUCE A BRAZED TUBE

Abstract

Method for manufacturing a brazed tube, comprising: a step A of forming, on a side edge section of a material plate formed from a solder sheet with a solder material layer over each of opposite surfaces thereof, a first inclined surface, such that the first inclined surface is located on a first face of the material plate and is inclined from the first face to a second face of the material plate as it approaches a distal end of one side edge section, and of forming a first flat surface, which is not covered by the solder material layer, between the first inclined surface and the second face, such that the first flat surface forms an obtuse angle with respect to the first inclined surface; a step B of forming, on the other side edge section of the material plate, a second inclined surface, such that the second inclined surface is located on the second face of the material plate and is inclined from the second face to the first face of the material plate as it approaches a distal end of the other side edge section, and of forming a second flat surface between the second inclined surface and the second face, such that the second flat surface forms an obtuse angle with respect to the second inclined surface, and furthermore of forming an acute-angled edge section between the first face and the second inclined surface of the material plate and of providing sections without the solder material layer on the side edge section of the first face of the material plate and on the side edge section of the second inclined surface of the material plate,where the sections are adjacent to the edge section; , a step C of forming the material sheet into a tubular shape, such that the first surface of it is on the outside, such that the first and second inclined surfaces of the opposite side edge sections are in surface contact with each other, and the first and second flat surfaces of the opposite side edge sections abut each other, in order to obtain a tubular soldering tube body; and a step D of soldering together the first and second inclined surfaces or the first and second flat surfaces of the opposite side edge sections of the material plate that forms the tubular soldering tube body, by making use of the solder material layer of the material plate, wherein, after one of steps A and B is performed, the remaining of steps A and B is performed, and then steps C and D are performed in this sequence.

Description

Technical field

[0001] The present invention relates to a method for manufacturing a brazed tube. More precisely, the present invention relates to a method for manufacturing a brazed tube suitable for use as a header in a heat exchanger, such as a condenser or evaporator for vehicle air conditioning systems, or an oil cooler for motor vehicles, and to a method for manufacturing such a brazed tube.

[0002] In the present description, the upper, lower, left, and right are referred to as... Fig. 1. These are referred to as "top", "bottom", "left" and "right", respectively. It is worth noting that when describing with regard to... Fig. 7 the upper, lower, left and right in Fig. 7 is designated as "top", "bottom", "left" and "right", respectively. Furthermore, in this description, the term "aluminium" includes not only pure aluminum but also aluminum alloys. State of the art

[0003] Fig. Figure 7 shows a heat exchanger 1, which is widely used as a condenser in a vehicle air conditioning system (see Patent Document 1). The heat exchanger 1 comprises a pair of vertically extending aluminum headers 2 and 3, spaced apart from each other in the left-right direction; a plurality of aluminum heat tubes 4, arranged between the headers 2 and 3, spaced apart from each other in the vertical direction, with opposite end sections of the tubes connected to the corresponding headers 2 and 3; aluminum corrugated fins 5, each arranged between and soldered to adjacent heat tubes 4, or arranged and soldered to the outside of the uppermost or lowermost heat tube 4; and side plates 6, arranged and soldered to the outside of the uppermost and lowermost corrugated fins 5.The left header 2 is divided into upper and lower header sections 2a and 2b by means of a separating element 7, which is positioned higher than the center of the header with respect to the vertical direction. The right header 3 is divided into upper and lower header sections 3a and 3b by means of another separating element 7, which is positioned lower than the center of the header with respect to the vertical direction. A fluid inlet (not shown) is formed on the upper header section 2a of the left header 2, and an inlet element 8 with a fluid inlet passage 8a is soldered to the upper header section 2a such that the fluid inlet passage 8a is connected to the fluid inlet.A fluid outlet (not shown) is formed on the lower header section 3b of the right header 3, and an outlet element 9 with a fluid drain passage 9a is soldered to the lower header section 3b such that the fluid drain passage 9a is in contact with the fluid outlet.

[0004] Each of the left and right headers 2 and 3 of the capacitor 1 described above is formed from a soldered tube 10 and aluminum sealing elements 11. The soldered tube 10 is manufactured by a process in which an aluminum (hard) solder sheet (material plate) with a layer of solder material over each of its opposing surfaces is formed into a tubular shape, with opposing side edge sections partially overlapping and soldered together. The sealing elements 11 are soldered to opposite ends of the soldered tube 10 to close the opposing end openings of the soldered tube 10.

[0005] Although not shown in the drawings, the soldered tube 10 is designed such that, from the opposite side edge sections of the material plate, which overlap each other, orThe first side edge section, located on the inside, has a first inclined surface formed on the outer surface of the first side edge section, the first inclined surface extending over the entire thickness of the material plate and sloping inwards towards the distal end; the second side edge section, located on the outside, has a second inclined surface formed on the inner surface of the second side edge section, the second inclined surface extending over the entire thickness of the material plate and sloping outwards towards the distal end; and the first and second inclined surfaces are soldered together as they are brought into surface contact. The separating element 7 is inserted into the soldered tube 10 through a separating element receiving slot and is soldered to the soldered tube 10.The separating element receiving slot is formed in the soldered tube 10 such that the slot extends over the opposite, overlapping side edge sections of the material plate. The fluid inlet (the fluid outlet) is also formed in the soldered tube 10 such that the fluid inlet (the fluid outlet) extends over the opposite, overlapping side edge sections of the material plate.

[0006] The soldered tube described above is manufactured using the following method.

[0007] This means that on one lateral edge section of a material plate formed from an aluminum solder sheet with a solder layer over each of its opposing surfaces, a first inclined surface is formed over the entire thickness of the material plate, such that the first inclined surface slopes from the first surface to the second surface of the material plate as it approaches the distal end. Furthermore, on the other lateral edge section of the material plate, a second inclined surface is formed over the entire thickness of the material plate, such that the second inclined surface slopes from the second surface to the first surface of the material plate as it approaches the distal end.The material sheet is then formed into a tubular shape such that the first surface forms an outer surface, and the two inclined surfaces are brought into surface contact with each other, thereby obtaining a tubular body, which is to become the soldered tube (hereinafter referred to as a "tubular soldering tube body"). In this state, the inclined surfaces are soldered together using the solder material layers of the material sheet. Thus, the soldered tube 10 is completed.

[0008] Incidentally, in such a process for manufacturing a soldered tube, if a tubular solder tube body 18 is obtained by forming a material 15 into a tubular shape, as in Fig. As shown in Figure 8, two inclined surfaces 16 and 17 can slide against each other and produce a deviation or offset in the thickness direction of the material plate 15. In such a case, a step can form on or at the outer surface of the tubular blowpipe body 18. Furthermore, since a round or rounded surface 19 is formed between the first inclined surface 16 and the outer surface of the tubular blowpipe body 18, the round surface 19 can form a step on the outer surface of the tubular blowpipe body 18.

[0009] If a step is formed on the outer surface of the tubular solder tube body 18, the following problems may occur in some cases. Generally, the alternating soldering of the inclined surfaces 16 and 17 of the tubular solder tube body 18 is carried out simultaneously with the soldering of all the components of the capacitor 1. Therefore, if a step is formed on the outer surface of the tubular solder tube body 18, a soldering failure or defect may occur after soldering the inlet element (8) or the outlet element (9) to the tubular solder tube body 18 (see Fig. 9) To prevent the occurrence of such a problem, arduous work must be carried out; in particular, it is necessary to prevent the inclined surfaces 16 and 17 from sliding against each other during the manufacture of the tubular soldering tube body 18, in order to prevent the formation of a step on the outer surface of the tubular soldering tube body 18. Therefore, the problem arises that the work to manufacture the soldered tube becomes more complicated.

[0010] Patent Publication 1: Japanese Patent Publication (kokoku) No. H03-18982 B2.

[0011] US 5,243,842 A relates to a method for manufacturing a brazed metal tube having elliptical tube insertion openings and guide lugs extending from at least one of the opposite edges defining the minor axis of each opening, the guide lugs extending in the insertion direction of the flat tubes. In the method, lateral ends of a strip of tubing are pressed in the direction of its thickness. This pressing of the lateral ends is effected in opposite directions, i.e., upward for one of the lateral ends and downward for the other lateral end. Both of the thus beveled ends are covered with a layer of brazing compound. Disclosure of the invention Problems to be solved by the invention

[0012] One object of the present invention is to solve the above problem and to provide a method by which a brazed tube which has no step on an outer surface thereof can be easily manufactured. Means of solving the problems

[0013] To achieve the above objective, the present invention comprises the following modes. 1) A method for producing a brazed tube, comprising a step A of forming, on a side edge section of a material plate formed from a solder sheet with a brazing material layer over each of its opposite surfaces, a first inclined surface, such that the first inclined surface is located on a first face of the material plate and is inclined from the first face to a second face of the material plate as it approaches a distal end of one side edge section, and of forming a first flat surface, which is not covered by the brazing material layer, between the first inclined surface and the second face, such that the first flat surface forms an obtuse angle with respect to the first inclined surface; a step B of forming, on the other side edge section of the material plate, a second inclined surface,such that the second inclined surface is located on the second face of the material plate and is inclined from the second face towards the first face of the material plate as it approaches a distal end of the other side edge section, and forming a second flat surface between the second inclined surface and the second face, such that the second flat surface forms an obtuse angle with respect to the second inclined surface, and furthermore forming an acute-angled edge section between the first face and the second inclined surface of the material plate, and providing sections without the solder material layer on the side edge section of the first face of the material plate and on the side edge section of the second inclined surface of the material plate, the sections being adjacent to the edge section; a step C of forming the material plate into a tubular shape,such that the first surface thereof is located on the outside, such that the first and second inclined surfaces of the opposite side edge sections are in surface contact with each other, and the first and second flat surfaces of the opposite side edge sections abut each other to obtain a tubular soldering tube body; and a step D of soldering together the first and second inclined surfaces or the first and second flat surfaces of the opposite side edge sections of the material plate forming the tubular soldering tube body, by making use of the solder material layer of the material plate, wherein, after one of steps A and B is carried out, the remaining of steps A and B is carried out, and then steps C and D are carried out in this sequence. 2) Method for producing a brazed tube according to paragraph 1), wherein the first inclined surface of the material plate formed in step A and the second inclined surface and the second flat surface of the material plate formed in step B are each covered by the brazing material layer. 3) Method for producing a soldered tube according to paragraph 1), wherein, in step A, a section of the material plate between the first surface and the first inclined surface bulges partially towards the side of the first surface in order to form an obtuse-angled edge section between the first surface and the first inclined surface of the material plate. 4) Method for producing a soldered tube according to paragraph 1), wherein, in step A, the first flat surface is formed such that the first flat surface intersects the second surface of the material plate perpendicularly. 5) Method for producing a soldered tube according to paragraph 1), wherein, in step B, the second flat surface is formed such that the second flat surface intersects the second surface of the material plate perpendicularly. 6) Method for producing a brazed tube according to paragraph 1), wherein, in step B, the second flat surface is formed such that the width of the second flat surface is equal to or greater than 20% of the thickness of the material plate. 7) Method for producing a brazed tube according to paragraph 1), wherein, in step B, the second flat surface is formed such that the width of the second flat surface is smaller than that of the first flat surface formed in step A. 8) Method for producing a soldered tube according to paragraph 1), wherein the tubular solder tube body obtained in step C has a step-free, smoothly connected inner surface at a point where the first and the second flat surfaces are in contact with each other. 9) Method for manufacturing a header for a heat exchanger, wherein in step C of the method for manufacturing a brazed tube according to one of paragraphs1) to 8), before the material sheet is formed into a tubular shape, a curved wall section, bulging towards the side of the first surface and having an arcuate transverse cross-section, is formed on an intermediate section of the material sheet with respect to a width direction thereof, and wherein a plurality of heat pipe receiving slots, extending in a circumferential direction of the curved wall section, are formed in the curved wall section at predetermined intervals along a longitudinal direction of the material sheet; and wherein, after completion of step C, closure elements are arranged on opposite end sections of the tubular solder pipe body formed from the material sheet and are soldered to the tubular solder pipe body, simultaneously with the reciprocal orDouble-sided (hard) soldering of the first and second inclined surfaces and alternating (hard) soldering of the first and second flat surfaces in step D. 10) Method for manufacturing a heat exchanger comprising a pair of headers spaced apart from each other, a plurality of heat tubes arranged between the headers and having opposite end sections connected to the corresponding headers, and fins arranged between adjacent heat tubes, wherein, after completion of step C of the method according to paragraph9) Two tubular solder tube bodies, each formed from the material sheet, are arranged such that they are spaced apart from each other; wherein the opposite end sections of the heat tubes are inserted into the heat tube receiving slots of the corresponding tubular solder tube bodies; wherein the fins are arranged between adjacent heat tubes; and wherein the heat tubes are soldered to the tubular solder tube bodies and the fins are soldered to the heat tubes, simultaneously with the alternating (hard) soldering of the first and the second inclined surface, the alternating (hard) soldering of the first and the second flat surface, and the (hard) soldering of the closure elements to the tubular solder tube bodies in step D. 11) Method for manufacturing a heat exchanger according to paragraph 10), wherein, after completion of steps A and B, recesses are formed at corresponding positions of the opposite side edge sections of the material plate from which at least one tubular soldering tube body is formed, thereby forming a separating element receiving slot over the opposite side edge sections of the tubular soldering tube body obtained in step C; wherein a separating element is inserted into the tubular soldering tube body through the slot before carrying out step D; and wherein the separating element is soldered to the tubular soldering tube body simultaneously with the (hard) soldering of the relevant components in step D. Effects of the invention

[0014] The method for manufacturing a brazed tube according to paragraph 1) has the following advantage. In the tubular brazing tube body, which is formed in step C by shaping the material sheet into a tubular form, the flat surfaces of the opposing side edge sections abut each other, thus preventing any misalignment between the two inclined surfaces. This prevents the formation of a step on the outer surface of the tubular brazing tube body. Consequently, the manufactured (hard) brazed tube has no step on its outer surface. Furthermore, since the misalignment between the two inclined surfaces can be prevented by shaping the material sheet into a tubular form such that the two flat surfaces abut each other, no special work is required to prevent the misalignment, and the manufacturing process is simplified.Furthermore, since the formation of a step on the outer surface of the tubular soldering tube body is prevented, the following advantage is achieved. For example, if an additional component is soldered to the tubular soldering tube body simultaneously with its production, such that the component extends over the opposite side edge sections of the material plate of the tubular soldering tube body, no gap forms between the additional component and the outer surface of the tubular soldering tube body. Consequently, it becomes possible to prevent the occurrence of solder failure between the manufactured soldered tube and the additional component.

[0015] The methods for producing a brazed tube of paragraphs 3), 4) and 5) effectively prevent the formation of a step on the outer surface of the tubular brazing tube body before it is subjected to brazing, and the formation of a step on the outer surface of the produced brazed tube.

[0016] The method for producing a soldered tube of paragraph 6) more reliably prevents the misalignment between the two inclined surfaces of the tubular soldering tube body in a state in which the opposite side edge sections of the material plate have not yet been soldered together. Brief description of the drawings Fig. Figure 1 is a group of vertical cross-sectional views showing, in sequence of steps, a process for manufacturing tubular solder tube bodies used in the headers of a heat exchanger. Fig. 2 is a group of partially enlarged views of Fig. 1. Fig. Figure 3 is a cross-sectional view showing, on an enlarged scale, a section of a tubular blowpipe body. Fig. Figure 4 is a perspective view, partially broken down into individual parts, showing a process of combining the tubular soldering tube body, heat tubes and an inlet element. Fig. Figure 5 is a perspective view, partially broken down into individual parts, showing a process of combining the tubular soldering tube body and a separating element. Fig. Figure 6 is a cross-sectional view showing a state in which an inlet element or an outlet element is combined with the tubular soldering tube body. Fig. Figure 7 is a perspective view showing the overall structure of a heat exchanger used as a condenser in a vehicle air conditioning system. Fig. Figure 8 is a cross-sectional view showing, on an enlarged scale, a section of a tubular solder tube body used in the headers of a conventional heat exchanger. Fig. 9 is a cross-sectional view showing a state in which an inlet element or an outlet element is connected to the tubular soldering tube body of Fig. 8 is combined. Best way to implement the invention

[0017] One embodiment of the present invention will be described next with reference to the drawings.

[0018] In this embodiment, the present invention is applied to the in Fig. The heat exchanger shown in section 7 is used. The following description refers to elements identical to those of Fig. 7 are, by the same reference symbols as those used to describe Fig. 7 are used, designated.

[0019] The Fig. 1 and Fig. Figure 2 shows a method for manufacturing a tubular soldering tube body in a header, and the Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 shows a method for manufacturing a heat exchanger.

[0020] First, a material plate 20 is produced, which is formed from a solder sheet with an aluminum solder material layer 20a on each of its opposing surfaces (see Fig. 1(a) and Fig. 2(a)). Subsequently, a right-side edge section of the material plate 20 is pressed from its upper and lower sides, for example by means of a press forming process, thereby forming a first inclined surface 21 on the upper surface of the material plate 20, such that the first inclined surface 21 slopes from the side of the upper surface (first surface) towards the side of the lower surface (second surface) of the material plate 20 as it approaches the distal end (right end), and a first flat surface 22 is formed between the lower end of the first inclined surface 21 and the lower surface of the material plate 20, such that the first flat surface 22 forms an obtuse angle with respect to the first inclined surface 21 and intersects the lower surface of the material plate 20 perpendicularly (see Fig. 1(b)) (Step A). ​​Since the first inclined surface 21 and the first flat surface 22 are formed on the material sheet 20 - which is formed from a solder sheet with an aluminum solder layer 20a on each of its opposite surfaces - by the press forming operation, which presses the material sheet 20 from its top and bottom sides, the first inclined surface 21 is covered by the solder layer 20a (see Fig. 2(b)). Remarkably, the first flat surface 22 is not covered by the solder material layer 20a. Furthermore, in step A, a section of the material plate 20 between the upper surface and the first inclined surface 21 is caused to bulge upwards, forming an obtuse-angled edge section 23 between the upper surface of the material plate 20 and the first inclined surface 21.

[0021] Subsequently, a left lateral edge section of the material plate 20 is pressed from its upper and lower sides, for example by means of a press forming process, thereby forming a second inclined surface 24 on the lower surface of the material plate 20, such that the second inclined surface 24 slopes from the side of the lower surface (second surface) towards the side of the upper surface (first surface) of the material plate 20 as it approaches the distal end (left end), and a second flat surface 25 is formed between the lower end of the second inclined surface 24 and the lower surface of the material plate 20, such that the second flat surface 25 forms an obtuse angle with respect to the second inclined surface 24 and intersects the lower surface of the material plate 20 perpendicularly (see Fig. 1(c)) (Step B). Since the second inclined surface 24 and the second flat surface 25 are formed on the material sheet 20 - which is formed from a solder sheet with an aluminum solder layer 20a on each of its opposite surfaces - by the press forming operation, which presses the material sheet 20 from its top and bottom sides, both the second inclined surface 24 and the second flat surface 25 are covered by the solder layer 20a (see Fig. 2(c)). In step B, the width of the second flat surface 25, as measured along the vertical direction, is preferably made equal to 20% or more of the thickness of the material plate 20. Notably, the width of the second flat surface 25, as measured along the vertical direction, is smaller than that of the first flat surface 22. Furthermore, in this step B, an acute-angled edge section 26 is formed between the upper surface of the material plate 20 and the second inclined surface 24. The angle formed at the acute-angled edge section 26 between the upper surface of the material plate 20 and the second inclined surface 24 is the secondary angle of the angle formed at the obtuse-angled edge section 23 between the upper surface of the material plate 20 and the first inclined surface 21.Furthermore, the solder material layer 20a is not present on sections of a left side edge section of the upper surface of the material plate 20 and a left side edge section of the second inclined surface 24, the sections being adjacent to the edge section 26.

[0022] Remarkably, in the present embodiment, step B is performed after step A. Conversely, however, step A can be performed after step B.

[0023] Below, a recess 27 is provided to form a fluid inlet 30 (see Fig. 4) and a recess 28 for forming a separating element receiving slot 31 (see Fig. 5) formed at corresponding positions of the left and right edge sections of a material plate 20, which is used to form a left header 2 (see Fig. 1(d)). Similarly, a recess 27 for forming a fluid outlet and a recess 28 for forming a separating element receiving slot 31 are formed at corresponding positions of the left and right edge sections of another material plate 20, which is used to form a right header 3 (see Fig. 1(d)).

[0024] Subsequently, after a curved wall section 32, which bulges upwards and has an arcuate transverse cross-section, is formed on an intermediate section of each material plate 20 with respect to the width direction, a plurality of heat pipe receiving elongated holes 33, extending in the circumferential direction of the curved wall section 32, are formed in the curved wall section 32 at predetermined intervals along the longitudinal direction of the material plate 20 (see Fig. 1(e)).

[0025] Remarkably, when the curved wall section 32 is formed, sections of the material plate 20 located on the left and right sides of the curved wall section 32 are slightly bent downwards, such that their upper surfaces are on the outside.

[0026] Subsequently, each material plate 20 is formed into a tubular shape such that the inclined surfaces 21 and 24 of the opposite side edge sections come into surface contact with each other, and the flat surfaces 22 and 25 of the opposite side edge sections abut each other, thereby obtaining a tubular soldering tube body 34 (see Fig. 1(f)) (Step C). As in Fig. As shown in Figure 3, since the flat surfaces 22 and 25 of the opposite side edges of the material plate 20, from which the tubular soldering tube body 34 is formed, abut each other, an offset between the inclined surfaces 21 and 24 of the tubular soldering tube body is prevented, so that no step is formed on the outer surface of the tubular soldering tube body 34.Furthermore, the obtuse-angled edge section 23 is formed between the upper surface of the material plate 20 and the first inclined surface 21; the acute-angled edge section 26 is formed between the upper surface of the material plate 20 and the second inclined surface 24; and the angle formed at the obtuse-angled edge section 23 between the upper surface of the material plate 20 and the first inclined surface 21, and the angle formed at the acute-angled edge section 26 between the upper surface of the material plate 20 and the second inclined surface 24, are secondary angles. These also prevent the formation of a step on the outer surface of the tubular soldering tube body 34. Moreover, when the material plate 20 is formed into a tubular shape, it is wound around a mandrel (not shown).Therefore, the inner surface of the tubular soldering tube body 34 has no step and is smoothly joined at a point where the flat surfaces 22 and 25 come into contact with each other.

[0027] Notably, on the tubular soldering tube body 34 of the left header 2, the liquid inlet 30 is formed by the recess 27, and the separating element receiving slot 31 is formed by the recess 28. On the tubular soldering tube body 34 of the right header 3, the liquid outlet is formed by the recess 27, and the separating element receiving slot 31 is formed by the recess 28.

[0028] Furthermore, flat heat tubes 4 are manufactured, wave fins 5 made of aluminum, side plates 6 made of an aluminum solder sheet with a brazing material layer over each of its opposite sides, separating elements 7 made of aluminum, an inlet element 8 made of aluminum, and an outlet element 9 made of aluminum.

[0029] Fig. Figure 4 shows the heat pipes. Each heat pipe is made from a metal plate formed from an aluminum solder sheet with a layer of solder material on each of its opposite sides. The plate comprises two flat-wall sections, a connecting section that joins the two flat-wall sections and forms one side wall, side wall ridges projecting upwards from the side edges of the two flat-wall sections opposite the connecting section and forming the opposite side wall, and a plurality of reinforcing wall ridges integrated into the two flat-wall sections. The metal plate is bent at the connecting section into a hairpin shape such that the side wall ridges and the reinforcing wall ridges engage with each other. In this state, the bent metal plate does not form a complete pipe.However, it is designated by the reference symbol 4, as in the case of the heat pipes of the in . Fig. 1. Heat exchanger shown. 1. Remarkably, the heat tubes 4 can be those made from an aluminum extrudate with a multitude of parallel fluid channels formed therein.

[0030] The two tubular soldering tube bodies 34 are subsequently arranged such that they are separated from each other; the plurality of heat tubes 4 and the wave fins 5 are arranged alternately; opposite end sections of the heat tubes 4 are inserted into the heat tube receiving slots 33 of the tubular soldering tube bodies 34 (see Fig. 4 and Fig. 6) Furthermore, the side plates 6 are arranged on the outer sides of the wave ribs 5 at opposite ends. Additionally, closure elements 11, made of aluminum, are arranged at opposite ends of each tubular soldering tube body 34. Furthermore, the aluminum separating element 7 is inserted into each separating element receiving slot 31 (see Fig. 5); the inlet element 8 is arranged such that its fluid inlet passage is connected to the fluid inlet 30; and the outlet element 9 is arranged such that its fluid outlet passage 9a is connected to the fluid outlet (see Fig. 4 and Fig. 6) All components are then temporarily attached using suitable means.

[0031] The components are then heated to a predetermined temperature, causing the inclined surfaces 21 and 24 and the flat surfaces 22 and 25 of each tubular solder tube body 34 to be soldered together, thus producing soldered tubes 10 (Step D). The closure elements 11 are then soldered to the soldered tubes 10 to form the headers 2 and 3; and the separating elements 7, the inlet element 8, and the outlet element 9 are soldered to the soldered tubes 10. Simultaneously, the sidewall combs and reinforcing wall combs of the heat tubes 4 are soldered together, giving each heat tube 4 the form of a complete tube. The heat tubes 4 are then soldered to the soldered tubes 10; the heat tubes 4 and the wave fins 5 are soldered together; and the wave fins 5 and the side plates 6 are soldered together. Thus, heat exchanger 1 is manufactured.

[0032] Heat exchanger 1 is used as a condenser in a refrigeration cycle that includes a compressor, condenser, pressure reducer, and evaporator, and uses a chlorofluorocarbon-based refrigerant. The refrigeration cycle is installed in a vehicle as a vehicle air conditioning system.

[0033] In each of the brazed tubes 10, which form the two headers 2 and 3 of the heat exchanger 1, of the opposite side edge sections of the material plate which overlap with each other, a first side edge section located on the inside has a first inclined surface formed on its outer surface, such that the first inclined surface slopes inwards towards the distal end; and a second side edge section located on the outside has a second inclined surface formed on its inner surface, such that the second inclined surface slopes outwards towards the distal end.A first flat surface is formed between the first inclined surface and the inner surface of the first side edge section, such that the first flat surface forms an obtuse angle with respect to the first inclined surface, and a second flat surface is formed between the second inclined surface and the inner surface of the second side edge section, such that the second flat surface forms an obtuse angle with respect to the second inclined surface, and wherein the first flat surface abuts the second flat surface. The opposing side edge sections of the material plate are soldered together in a state where the two inclined surfaces are in surface contact with each other, and the two flat surfaces are in surface contact with each other.Furthermore, an obtuse-angled edge section is formed between the outer surface and the first inclined surface of the first side edge section, and an acute-angled edge section is formed between the outer surface and the second inclined surface of the second side edge section, such that the outer surfaces of the opposite side edge sections are smoothly connected. Furthermore, the width of the second flat surface of the second side edge section, as measured along the thickness direction of the material sheet, is equal to or greater than 20% of the thickness of the material sheet; and the inner edge of the first flat surface of the first side edge section projects inward from the inner edge of the second flat surface of the second side edge section.

[0034] In the embodiment described above, the two headers of the heat exchanger are divided into equal numbers of header subsections by respective separating elements; a fluid inlet is formed in a longitudinal end section of a first header; and a fluid outlet is formed in the opposite longitudinal end section of a second header.The design of the headers is not limited to this, however, and can be designed such that a first header of the heat exchanger is divided into a plurality of header subsections by a separating element(s); wherein a second header has header subsections, one fewer than the header subsections of the first header, and wherein each of them faces two adjacent header subsections of the first header; wherein a fluid inlet is formed in the header subsection located at one end of the first header with respect to the longitudinal direction; and wherein a fluid outlet is formed in the header subsection located at the other end of the first header with respect to the longitudinal direction. Industrial applicability

[0035] The method for producing a brazed tube according to the present invention is suitable for producing headers of a heat exchanger, such as a condenser or an evaporator for vehicle air conditioning systems, or an oil cooler for motor vehicles.

Claims

[1] Method for producing a brazed tube, comprising: a step A of forming, on a side edge section of a material plate formed from a solder sheet with a solder material layer over each of opposite surfaces thereof, a first inclined surface, such that the first inclined surface is located on a first face of the material plate and is inclined from the first face to a second face of the material plate as it approaches a distal end of one side edge section, and of forming a first flat surface, which is not covered by the solder material layer, between the first inclined surface and the second face, such that the first flat surface forms an obtuse angle with respect to the first inclined surface; a step B of forming, on the other side edge section of the material plate, a second inclined surface, such that the second inclined surface is located on the second face of the material plate and is inclined from the second face to the first face of the material plate as it approaches a distal end of the other side edge section, and of forming a second flat surface between the second inclined surface and the second face, such that the second flat surface forms an obtuse angle with respect to the second inclined surface, and furthermore of forming an acute-angled edge section between the first face and the second inclined surface of the material plate and of providing sections without the solder material layer on the side edge section of the first face of the material plate and on the side edge section of the second inclined surface of the material plate,where the sections are adjacent to the edge section; , a step C of forming the material sheet into a tubular shape, such that the first surface of it is on the outside, such that the first and second inclined surfaces of the opposite side edge sections are in surface contact with each other, and the first and second flat surfaces of the opposite side edge sections abut each other, in order to obtain a tubular soldering tube body; and a step D of soldering together the first and second inclined surfaces or the first and second flat surfaces of the opposite side edge sections of the material plate that forms the tubular soldering tube body, by making use of the solder material layer of the material plate, wherein, after one of steps A and B is performed, the remaining of steps A and B is performed, and then steps C and D are performed in this sequence. [2] Method for producing a soldered tube according to claim 1, wherein the first inclined surface of the material plate formed in step A and the second inclined surface and the second flat surface of the material plate formed in step B are each covered by the solder material layer. [3] Method for producing a soldered tube according to claim 1, wherein, in step A, a section of the material plate between the first surface and the first inclined surface bulges partially towards the side of the first surface in order to form an obtuse-angled edge section between the first surface and the first inclined surface of the material plate. [4] Method for producing a soldered tube according to claim 1, wherein, in step A, the first flat surface is formed such that the first flat surface intersects the second surface of the material plate perpendicularly. [5] Method for producing a soldered tube according to claim 1, wherein, in step B, the second flat surface is formed such that the second flat surface intersects the second surface of the material plate perpendicularly. [6] Method for producing a brazed tube according to claim 1, wherein, in step B, the second flat surface is formed such that the width of the second flat surface is equal to or greater than 20% of the thickness of the material plate. [7] Method for producing a brazed tube according to claim 1, wherein, in step B, the second flat surface is formed such that the width of the second flat surface is smaller than that of the first flat surface formed in step A. [8] Method for producing a soldered tube according to claim 1, wherein the tubular solder tube body obtained in step C has a step-free, smoothly connected inner surface at a point where the first and the second flat surface are in contact with each other. [9] Method for manufacturing a header for a heat exchanger, wherein in step C of the method for manufacturing a brazed tube according to any one of claims 1 to 8, before the material plate is formed into a tubular shape, a curved wall section, which bulges towards the side of the first surface and has an arcuate transverse cross-section, is formed on an intermediate section of the material plate with respect to a width direction thereof, and wherein a plurality of heat tube receiving elongated holes, which extend in a circumferential direction of the curved wall section, are formed in the curved wall section at predetermined intervals along a longitudinal direction of the material plate;and wherein, after completion of step C, closure elements are arranged on opposite end sections of the tubular soldering tube body formed from the material plate and are soldered to the tubular soldering tube body, simultaneously with the alternating soldering of the first and second inclined surfaces and the alternating soldering of the first and second flat surfaces in step D.; [10] A method for manufacturing a heat exchanger comprising a pair of headers spaced apart from each other, a plurality of heat tubes arranged between the headers and having opposing end sections connected to the corresponding headers, and fins arranged between adjacent heat tubes, wherein, after completion of step C of the method according to claim 9, two tubular solder tube bodies, each formed from the material sheet, are arranged such that they are spaced apart from each other; wherein the opposing end sections of the heat tubes are inserted into the heat tube receiving slots of the corresponding tubular solder tube bodies; the fins are arranged between adjacent heat tubes;and the heat tubes are soldered to the tubular solder tube bodies and the fins are soldered to the heat tubes, simultaneously with the alternating soldering of the first and second inclined surfaces, the alternating soldering of the first and second flat surfaces, and the soldering of the closure elements to the tubular solder tube bodies in step D.; [11] Method for manufacturing a heat exchanger according to claim 10, wherein, after completion of steps A and B, recesses are formed at corresponding positions of the opposite side edge sections of the material plate from which at least one tubular soldering tube body is formed, whereby a separating element receiving slot is formed over the opposite side edge sections of the tubular soldering tube body obtained in step C; wherein a separating element is inserted into the tubular soldering tube body through the slot before carrying out step D; and the separating element is soldered to the tubular soldering tube body simultaneously with the soldering of the relevant components in step D.

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