WO1998044306A1

WO1998044306A1 - Heat exchanger tube and method of its manufacture

Info

Publication number: WO1998044306A1
Application number: PCT/JP1998/001370
Authority: WO
Inventors: Kazuki Hosoya; Akimichi Watanabe; Hirotaka Kado
Original assignee: Sanden Corporation
Priority date: 1997-03-28
Filing date: 1998-03-26
Publication date: 1998-10-08
Also published as: EP0907062A4; JPH10274489A; EP0907062A1

Abstract

A heat exchanger tube which has two flat plate parts defining therebetween a passage through which heat exchanging media flow and a folded part which is formed by folding at least one end part of at least one flat plate part so as to have a thickness which is an integral multiple of that of the flat plate part. The folded part and the corresponding end in the widthwise direction of the other flat plate part are joined together. The obtained tube has such features that the junction strength of the joined part is high enough to ensure high pressure resistance, that the internal dimensions of the tube can be changed easily and accurately, that flux can be applied sufficiently to necessary positions for soldering, and that it can facilitate the adoption of a reinforced structure at the central part in the widthwise direction of the tube.

Description

Specification

Tube for heat exchanger and method for producing the same

Technical field

The present invention relates to a heat exchanger tube and a method of manufacturing the same, and more particularly to a heat exchanger tube suitable for a vehicle heat exchanger and a method of manufacturing the same, and further relates to a heat exchanger including the heat exchanger tube.

Background technology

Conventionally, a tube for a heat exchanger, more specifically, a heat exchange tube through which a heat exchange medium flows in a heat exchanger, has conventionally been formed by, for example, bending a single flat plate material in the width direction by rolling. It was produced by joining the tips of the ends of the. In such a manufacturing method, as shown in FIG. 27, for example, a heat exchange tube 301 is formed in which the tips are butt-joined at a joint portion 302. The tips are joined, for example, by electrolytic welding.

In addition, as shown in Fig. 28, a flat plate as a tube forming material is bent intricately, a joint 312 is provided at the center in the width direction of the tube, and brazed at this portion to form a heat exchange tube. A method for forming 3 1 1 is also known (Japanese Unexamined Patent Publication No.

No. 2 357 71).

However, in the manufacturing method shown in Fig. 27, when the electrode tube in which one plate is roll-formed is used, the ends of the plates are welded and joined at the joining portion 302. Since the area is small and the bonding strength is low, the pressure resistance may be reduced. In addition, since it is necessary to roll a long material,

There is a problem that the processing cost of 301 increases. In addition, in the roll processing of long products, since they are often cut to a predetermined size after processing, defective products are likely to occur, and correction processing will be required later, and this tends to increase costs. is there. Furthermore, since the ends of the plates are only joined at the joints 302, the inner dimensions of the formed tubes 301, especially the height of the flow path, must be accurately determined to the target dimensions. And the dimensions may vary. Furthermore, when the target channel height is changed, it is difficult to accurately follow the change. In addition, the tube manufacturing method as shown in Fig. 28 has the following problems. is there. In other words, in a heat exchanger having a core portion in which tubes and fins are alternately arranged, a method of brazing by heating in a furnace with the core portion temporarily assembled is usually adopted. However, as shown in Fig. 28, with the structure in which the joint 312 for forming the tube is provided at the center in the width direction of the heat exchange tube 311, the flux does not rotate sufficiently at the brazing point. However, poor brazing may occur, and a defective portion may occur due to leakage of the heat exchange medium.

Furthermore, as shown in Fig. 28, the structure with a joint 312 extending in the direction transverse to the inside of the tube at the center of the tube 311 in the width direction ensures high strength of the tube 311. However, in the structure shown in Fig. 27 where there is no abutting part at the center of the tube 301 in the width direction, the core part when brazing the core part body is used. Tightening force due to the difference in the coefficient of thermal expansion between the main body and the brazing jig (a jig for temporarily fixing the core assembly) is applied to the core, causing the tube to be crushed or the brazing failure to occur. Location) may occur.

Disclosure of the invention

Therefore, an object of the present invention is to provide a heat exchanger tube having a sufficiently high joining strength at a joining portion, ensuring a sufficiently high pressure resistance, and easily and accurately changing the inner dimensions of the tube. A tube for a heat exchanger and a method of manufacturing the same, which can respond sufficiently, can sufficiently apply a flux to a necessary portion even at the time of brazing, and can easily adopt a reinforcing structure at a central portion in a width direction of the tube. Is to provide. In order to achieve the above object, a heat exchanger tube according to the present invention includes two flat plates facing each other and forming a flow path for a heat exchange medium therebetween, and at least one flat plate of at least one flat plate. A width direction end portion formed by folding the end portion, and a folded portion having a thickness of an integral multiple of the thickness of the plate forming the end portion, wherein the folded portion corresponds to the other flat plate portion And the widthwise ends thereof are joined to each other.

This heat exchanger tube has a bent portion integrally connecting the two flat portions at one widthwise end of the two flat portions, and the folded portion has the other width of the two flat portions. The folded portions may be formed at the end portions in the direction, and the folded portions may be joined to each other. Or, the above-mentioned folded portion is 6

Three

It is also possible to adopt a configuration in which the respective folded portions are formed at the width direction ends and the corresponding folded portions are joined to each other.

The folded portion may be formed by folding at least one width direction end of at least one flat plate portion at least once, and at least one width direction of at least one flat plate portion may be formed. It is also possible to adopt a configuration formed by bending the end multiple times. When the folded part is formed by bending multiple times, the first folded part makes surface contact with the inner surface of the flat tube, and the subsequent folded part makes surface contact with the previous folded part. Wrapped. Such a folded portion can be formed by, for example, press working.

In addition, an abutting portion is formed at the center in the width direction of one of the flat portions so as to protrude toward the other flat portion to a position substantially in contact with the other flat portion by bending the one flat portion itself. The structure can also be used. The folded portion can be joined to the corresponding end of the other flat plate by brazing. The following configuration may be further added to such a heat exchanger tube. For example, a structure in which an inner fin is provided between the flat plate portions can be adopted.o

Also, at least one of the flat portions is provided with a plurality of protrusions protruding inward of the tube, and the protrusions facing each other or the protrusions and the plate portion provided with the protrusions are opposed to each other. The inner surface of the flat plate portion can be configured to abut against each other. Further, the flat plate portion may be formed so as to bulge outward from the tube so that a substantially central portion in a width direction thereof becomes a vertex, so that a structure for improving the pressure resistance of the tube can be adopted.

Further, a structure may be provided in which grooves extending in directions intersecting with each other are provided on each opposing surface of the flat plate portion.

A heat exchanger according to the present invention has a structure of a tube for a heat exchanger as described above. The type of the heat exchanger is not particularly limited. For example, the present invention can be applied to a heat exchanger of a type in which tubes and fins are alternately arranged.

In addition, the method for producing a heat exchanger tube according to the present invention includes: (a) folding one end of the flat plate having a predetermined width to at least one end in the width direction; (B) bending the central portion in the width direction of the flat plate so that the folded portion is on the inner side, and heat exchange between (C) joining at least one of the folded portions formed at the end of one of the flat portions to the corresponding end of the other flat portion; It consists of a special method.

Further, the method for manufacturing a tube for a heat exchanger according to the present invention includes the steps of: (a) folding each end to at least both ends in the width direction of at least one of two flat plates each having a predetermined width; A folded portion having an integral multiple of the thickness of the plate forming the end portion is formed. (B) The folded portion of the flat plate having the folded portions formed at both ends in the width direction corresponds to the other flat plate. The method is characterized by joining the ends with each other

Also in such a manufacturing method, the folded portion can be formed by turning the width direction end of the flat plate once, or can be formed by turning a plurality of times. When the folded portion is formed by folding a plurality of times, the first folded portion is brought into surface contact with the flat plate, and the subsequent folded portion is brought into surface contact with the preceding folded portion. Such a folded portion is formed by, for example, press processing.

Also, before or after formation of the folded portion, one of the two flat portions forming the tube is bent into one of the two flat portions so that the other flat portion is substantially directed toward the other flat portion. Butts can be formed to protrude to a position where they come into contact. Further, the folded portion can be joined to a corresponding end of the flat plate portion facing the folded portion by brazing.

Also, in this manufacturing method, a step of interposing an inner fin between the flat plates for forming a tube can be added. Further, a plurality of protruding portions protruding inward of the tube when forming the tube may be formed on the flat plate. Further, grooves extending in directions intersecting with each other at the time of forming the tubes may be formed on the surfaces of the respective flat plate portions which are surfaces facing each other when the tubes are formed. In the above-described heat exchanger tube and the method of manufacturing the same, at least the folded portion formed at the widthwise end of the flat plate portion is formed by, for example, pressing. Can be molded. Therefore, the processing cost is low, and the pre-cut piece having a width of a predetermined dimension is pressed, so that processing defects do not occur and no correction processing is required. As a result, manufacturing costs are significantly reduced.

Also, instead of joining the ends by abutting each other as in the conventional case, the folded portion is brought into surface contact with the corresponding widthwise end portion of the other flat plate portion (this portion may also be formed in the folded portion). Since bonding can be performed in a state, the bonding area is sufficiently large, high bonding strength is secured, and high pressure resistance can be realized. The folded portion is turned one or more times so that the folded pieces are overlapped in a face-to-face contact state so as to have an integral multiple of the thickness of the plate forming the width direction end of the flat plate. Since it is formed, the high strength of the folded portion itself is ensured, and the high bonding strength is ensured by the bonding surface in the surface contact state as described above, and the high pressure resistance of the entire tube can be realized. Further, the thickness of the folded portion corresponds to the height of the flow path in the tube, and the thickness of the folded portion can be defined by the number of times of folding in the folded portion. In other words, the thickness of the folded portion, especially the thickness of the folded portion that contributes to the determination of the inner dimensions of the tube, can be determined by the number of times of folding, that is, the number of stacked folded pieces, greatly increasing the degree of freedom in design. Increase. When multiple turns are made or when folded parts are joined together, the thickness is determined by the thickness of the folded pieces, and the first folded piece and the tube inner surface forming surface of the flat plate part. By the contact, the dimensions are exactly determined by the thickness of the folded piece X the number of folded pieces. Therefore, the inner dimensions of the tube to be formed are also accurately determined to the target dimensions, and a highly accurate tube can be obtained.

Also, when the butted portion is provided, the butted portion can be formed by bending the flat plate portion itself, so that no portion requiring brazing or the like is generated at the center in the width direction of the tube, and the flux is not generated. It is possible to eliminate the possibility of insufficient application of the coating, poor brazing resulting therefrom, and the occurrence of defective spots due to leakage.

If the butted portion is provided, the tube can be reinforced at the center in the width direction while maintaining the above-mentioned effects, and when the core portion is brazed, the tube may be deformed and the core portion may be deformed. This makes it possible to prevent the occurrence of defective brazing or defective leakage due to the difference in the coefficient of thermal expansion from the brazing jig. Brief explanation of drawings

FIG. 1 is a front view of a heat exchanger according to one embodiment of the present invention.

FIG. 2 is a partial perspective view of the heat exchanger tube according to one embodiment of the present invention. FIG. 3 is a partial perspective view of a tube for a heat exchanger according to another embodiment of the present invention. FIG. 4 is a partial perspective view of a tube for a heat exchanger according to still another embodiment of the present invention.

FIG. 5 is a partial perspective view of a heat exchanger tube according to still another embodiment of the present invention.

FIG. 6 is a process flow chart showing a method for manufacturing the heat exchanger tube of FIG. FIG. 7 is a process flow chart showing a method for manufacturing the heat exchanger tube of FIG. FIG. 8 is a process flow chart showing a method of manufacturing the heat exchanger tube of FIG. FIG. 9 is a process diagram showing a method of manufacturing the heat exchanger tube of FIG. FIG. 10 is a partial perspective view of each heat exchanger tube according to still another embodiment of the present invention.

FIG. 11 is a partial perspective view of a heat exchanger tube according to still another embodiment of the present invention.

FIG. 12 is a partial perspective view of each heat exchanger tube according to still another embodiment of the present invention.

FIG. 13 is a partial perspective view of a heat exchanger tube according to still another embodiment of the present invention.

FIG. 14 is a process flow chart showing a method of manufacturing the heat exchanger tube of FIG. 10A.

FIG. 15 is a process diagram D—showing a method of manufacturing the heat exchanger tube of FIG. 11; FIG. 16 is a process flow chart showing a method for manufacturing the heat exchanger tube of FIG. 12A.

FIG. 17 is a process flow chart showing a method for manufacturing the heat exchanger tube of FIG. FIG. 18 is a partial perspective view of a tube showing a modification of the heat exchanger tube shown in FIG.

Fig. 19 is a tube section showing a modification of the heat exchanger tube shown in Fig. 10A. FIG.

FIG. 20A is a partial perspective view of a tube showing another modification of the heat exchanger tube shown in FIG. 2, and FIG. 20B is a cross-sectional view of the tube of FIG. 20A taken along line XXB—XXB. FIG.

FIG. 21A is a partial perspective view of a tube showing another modification of the heat exchanger tube shown in FIG. 10A, and FIG. 21B is a line XXIB-XXIB of the tube of FIG. 21A. FIG.

FIG. 22A is a partial perspective view of a tube showing still another modification of the heat exchanger tube shown in FIG. 2, and FIG. 22B is an enlarged front view of the tube of FIG. 22A. is there. FIG. 23A is a partial perspective view of a tube showing still another modification of the heat exchanger tube shown in FIG. 10A, and FIG. 23B is an enlarged front view of the tube of FIG. 23A. Confuse.

FIG. 24 is a partial plan view of the flat material before tube processing shown in FIG. 22A or FIG. 23A.

FIG. 25 is a sectional view of a tube showing still another modified example of the heat exchanger tube shown in FIG.

FIG. 26 is a sectional view of a tube showing still another modified example of the heat exchanger tube shown in FIG. 10A.

FIG. 27 is a partial perspective view of a conventional heat exchanger tube.

FIG. 28 is a partial perspective view of another conventional heat exchanger tube.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a heat exchanger 1 according to one embodiment of the present invention. The heat exchanger 1 has two tank sections 2 and 3 on the inlet and outlet sides, and is provided between the tank sections 2 and 3 and communicates with both tank sections 2 and 3. It has a plurality of heat exchange tubes 4 and corrugated fins 5, and the heat exchange tubes 4 and the fins 5 are arranged alternately. In the present embodiment, side plates 7 and 8 are provided on the outermost layer of the core 6 having the heat exchange tubes 4 and the fins 5. Also, the outer surface of one side plate 8 and the side surface of one tank 2 Brackets 9 and 10 are joined. The tanks 2 and 3 are provided with fittings 11 and 12 for connecting pipes or other devices, respectively. The heat exchange tube 4 of such a heat exchanger 1 is configured, for example, as shown in FIGS. 2 to 5 or FIGS. 10 to 13 (heat exchange tubes 21, 31, 41, 51). , 1 2 1 a, 1 2 1 b, 1 2 1 c, 1 3 1, 1 4 1 a, 1 4 1 b, 1 4 1 c, 1 5

1) o

The heat exchange tubes 21 of the embodiment shown in FIG. 2 are opposed to each other at intervals and form two heat exchange medium flow paths 22 between them, and two flat plate portions 23 a and 23 b, and both flat plate portions 23 a,

A bent portion 24 that integrally connects both flat portions 23a and 23b at one widthwise end of 23b and the other widthwise end of both flat portions 23a and 23b It has folded portions 25a and 25b formed in the portions. The folded portions 25a and 25b are formed by bending each flat plate portion 23a and 23b so that each end is folded. In the folded portions 25a and 25b, the inner surface side of the folded portions 25a and 25b and the tube inner surface side of the flat plate portions 23a and 23b are in surface contact with each other and face each other. The folded portions 25a and 25b are folded so that the outer surfaces thereof are formed on surfaces extending parallel to each other. Such folded portions 25a and 25b are formed by press working. The two folded portions 25a and 25b are joined to each other on the outer surface side (opposed surface side) extending parallel to each other by brazing (joining portion 26).

The heat exchange tube 31 of the embodiment shown in FIG. 3 includes two flat plate portions 3 3 a and 3 3 b forming a heat exchange medium flow path 32, similar to the above heat exchange tube 21, and both flat plate portions 3. 3a,

It has a bent portion 3 4 for integrally connecting 33 b and a folded portion 35 a, 35 b formed at one end in the width direction of both flat portions 33 a, 33 b. The folded portions 35a and 35b are joined to each other on the outer surface side of the folded portion by brazing (joining portion 36). In the present embodiment, the flat plate portion 33 b is bent at the center in the width direction of the one flat plate portion 33 b so that the flat plate portion 33 b is substantially bent toward the other flat plate portion 33 a. A butting portion 37 is formed to protrude to a position where it contacts the inner surface of 3a. The tip end surface of the butted portion 37 may be joined to the inner surface of the flat plate portion 33a, or may simply be in contact. The heat exchange tubes 41 of the embodiment shown in FIG. 4 are opposed to each other at intervals and form two heat exchange medium flow paths 42 between them, and two flat plate portions 4 3 a and 4 3 b, and both flat plate portions 4 3 a, 43b, at both ends in the width direction, each of which has a folded portion 44a, 44b and 45a, 45b which are bent so as to be folded, and the corresponding folded portion. The pieces 44a and 45a and the pieces 44b and 45b are joined to each other on the outer surface side of the turn by brazing (joints 46a and 46b).

The heat exchange tube 51 of the embodiment shown in FIG. 5 includes two flat plate portions 53 a and 53 b forming a heat exchange medium flow path 52 similar to that shown in FIG. a, 53b, each having a folded portion 54a, 54b, 55a, 55b, and corresponding folded portions 54a, 55a, and 54. b and 55 are joined to each other on the outer side of the turn by brazing (joints 56a and 56b). In the present embodiment, the flat plate portion 53 b is bent at the center in the width direction of the one flat plate portion 53 b so that the flat plate portion 53 b is substantially flattened toward the other flat plate portion 53 a. A butted portion 57 is formed to protrude to a position where it abuts the inner surface of 3a. The tip end surface of the butted portion 57 may be joined to the inner surface of the flat plate portion 53a, or may be merely in contact.

The heat exchange tubes 21, 31, 41, 51 shown in FIGS. 2 to 5 are manufactured by the method shown in FIGS. 6 to 9, respectively.

FIG. 6 shows a method of manufacturing the heat exchange tube 21 shown in FIG. First, a flat plate 63 having a predetermined width is formed from a wide flat plate 61 as a tube forming material by cutting using a suitable cutter device 62 or the like. Next, both ends in the width direction of one flat plate 63 having a predetermined width are bent so as to be folded toward the same surface (the upper surface side in FIG. 6), and the folded portions 25 a and 25 are provided at the both ends. Form b.

Next, the central part in the width direction of the flat plate 63 is bent toward the above-mentioned surface (the upper surface side in FIG. 6) to form a bent part 24, which faces each other at intervals and has a heat exchange medium between them. The two flat portions 23 a and 23 b forming the flow path 22 are formed. Then, the heat exchange tubes 21 shown in FIG. 2 are completed by joining the folded portions 25a and 25b to each other on the outer surface side of the folded portions (joined portions 26).

FIG. 7 shows a method of manufacturing the heat exchange tube 31 shown in FIG. First, A flat plate 71 having a predetermined width slightly larger than that shown in FIG. 6 is formed from the wide flat plate 61 as a material by cutting with a cutter device 62 or the like. Next, a butt portion 37 is formed at a predetermined position of the single flat plate 71 by bending. Then, both ends in the width direction of the flat plate 71 are bent so as to be folded on the same surface side as the butted portion 37, and folded portions 35a and 35b are formed at both ends. Next, the center of the flat plate 71 in the width direction is bent on the same surface side as the butted portion 37 to form a bent portion 34, which faces each other at intervals and has a heat exchange medium flow path therebetween. The two flat portions 33a and 33b that form 32 are formed. The heat exchange tube 31 shown in FIG. 3 is completed by joining the folded portions 35a and 35b to each other on the outer surface side of the folded portion (joined portion 36).

FIG. 8 shows a method of manufacturing the heat exchange tube 41 shown in FIG. First, two flat plates 81a and 81b having the same width are formed from a wide flat plate 61 as a raw material by cutting with a cutter device 62 or the like. Next, folded portions 44a and 44b and folded portions 45a and 45b are formed at both ends of the two flat plates 81a and 81b by bending. Both flat plates 8 1a, 8 1b, both flat plate parts 4 3a,

As 4 3 b, the corresponding folded portions 4 4 a and 4 5 a and the folded portions 4 4 b and 4

5b are positioned so as to face each other, and the corresponding folded portions 44a and 45a and the folded portions 44b and 45b are joined to each other on the outer surface side of the folded portion (joining portion 46). a, 46 b) As a result, the heat exchange tube 41 having the heat exchange medium flow path 42 therein as shown in FIG. 4 is completed.

FIG. 9 shows a method of manufacturing the heat exchange tube 51 shown in FIG. First, two flat plates 91a and 91b having different widths are formed from a wide flat plate 61 as a material by cutting with a cutter device 62. Next, an abutting portion 57 is formed by bending at the center in the width direction of the wider flat plate 91b. The folded portions 54a and 54b and the folded portions 55a and 55b are formed at both ends of both flat plates 91a and 91b by bending. The two flat plates 91a and 91b are used as the two flat plate portions 53a and 53b, and the corresponding folded portions 54a and 55a and the folded portions 54b and 55b are positioned so as to face each other. The corresponding folded portions 54a and 55a and the folded portions 54b and 55b are connected to each other on the outer surface side of the folded portion. By joining (joining portions 56a and 56b), the heat exchange tube 51 having the heat exchange medium flow path 52 therein as shown in FIG. 5 is completed.

In the heat exchanger tube manufactured and configured as described above, since the folded portions are brazed to each other on the outer surface side, a sufficiently large bonding area is obtained, and high bonding strength and high tube pressure resistance are obtained. can get. In addition, concerns such as leaks will be resolved. Therefore, a heat exchanger with high pressure resistance performance can be realized.

The folded portion formed at the width direction end of each flat plate portion can be formed by press working. Therefore, the conventional roll processing is not required, and the processing cost, and thus the tube, and the production cost of the heat exchanger can be significantly reduced. In addition, since no roll processing is performed, correction after processing is not required, and the occurrence rate of defective products can be significantly reduced, making it easier to manufacture and further reducing manufacturing costs.

In addition, since there is no brazing portion at the center in the width direction of the tube, there is no possibility of a failure in the rotation of the flux. Also, the butted portion for reinforcing the tube can be easily formed by bending one flat plate portion itself, so that a tube structure having high strength can be easily realized.

Moreover, since the abutting portion is basically a region where it is not necessary to flow the flux from another portion or to apply the flux from the outside, there is a problem with the flux around as shown in the structure shown in Fig. 27. There is no occurrence. Therefore, the occurrence of a brazing defect can be easily prevented.

Furthermore, in the structure with the butted part, when the core part 6 is fixed with a jig, it is generated due to the difference in the coefficient of thermal expansion between the core part and the brazing jig. High resistance to deformation and displacement. As a result, it is possible to effectively prevent deformation of the tube and occurrence of defective brazing. Therefore, it is possible to manufacture a high-performance heat exchanger that has been reliably brazed and has no fear of leakage. In the above description of the manufacturing method, the butted portion is formed before the formation of the end folded portion. However, it can be formed after the formation of the end folded portion. Next, the heat exchange tubes of FIGS. 10 to 13 will be described. Each of these tubes is formed at least at one end in the width direction of at least one flat plate by bending the end plural times, and is an integral multiple of the thickness of the plate forming the end. of A folded portion having a thickness is formed.

The heat exchange tubes 1 2 1 a of the embodiment shown in FIG. 10A face each other at intervals and form two heat exchange medium flow paths 1 2 2 between the two flat plate portions 1 2 3 a, 1 2 3 b And a bent portion 1 2 4 that integrally connects the flat plate portions 1 2 3 a and 1 2 3 b at one end in the width direction of the flat plate portions 1 2 3 a and 1 2 3 b; A folded portion 125a formed at the other widthwise end of the flat plate portion 123a and bent so that the end portion is folded a plurality of times (twice in this embodiment) in opposite directions to each other. The folded portion 125 a and the corresponding end portion 125 b of the other flat plate portion 123 b (the folded portion is not formed at the end portion in this embodiment). Are joined to each other (joining portion 126). In the folded part 1 25 a, the first folded piece 1 27 a is in close contact with the inner surface of the tube of the flat plate 1 2 3 a by surface contact, and the subsequent folded piece 1 27 b is folded in front. It is folded back so as to be in close contact with the one-side part 127 a. Then, the folded-back portion 1 27 b of the folded portion 1 25 a is joined by brazing so as to be in close contact with the corresponding end portion 125 b of the other flat plate portion 123 b by surface contact. Have been. Such a folded portion 125a is formed by press working.

O o

In the heat exchange tube 1 2 1 b of the embodiment shown in FIG. 10B, a folded portion 1 288 that is folded only once is formed at the corresponding one end of the other flat plate portion 1 23, and the folded portion is formed. The 125a and the folded portion 128 are joined by brazing so as to be brought into close contact by surface contact. In the heat exchange tube 12 1 c of the embodiment shown in FIG. 10C, the folded portions 1 25 a are folded twice at the corresponding ends of both flat plate portions 123 a and 123 b respectively. Are formed, and the folded portions 125a are joined together by brazing so as to be in close contact with each other by surface contact. In this way, the number of turns of the folded portion and the shape of the corresponding end of the other flat plate 1 2 3 b can be freely set, and the inner dimensions of the tube (flow path height) are determined by the two flat plates 1 2 3 a The target dimensions can be accurately determined by the number of folded pieces interposed between the first and second b. Of course, internal dimensions other than those shown in the figure are also possible. Depending on the target dimensions, the number of folded pieces interposed between the flat plates 1 2 3 a and 1 2 3 b, the number of turns in the folded section You can decide.

The heat exchange tube 13 1 in the embodiment shown in FIG. 11 is the same as the heat exchange tube 12 8/4306 1370

13

Bending to integrally connect the two flat plates 1 3 3 a, 1 3 3 b and the flat plates 1 3 3 a, 1 3 3 b forming the heat exchange medium flow path 13 2 Formed at the other widthwise end of the portion 134 and one of the flat plate portions 133a, and the end is bent a plurality of times (twice in this embodiment) so as to be folded in opposite directions. A folded portion 135a, and the folded portion 135a and a corresponding end 135b of the other flat plate portion 133b (in the present embodiment, the folded portion is provided at the end. Are not formed) and are joined to each other (joined portion 1336). In the present embodiment, the flat plate portion 133 b is bent at the center in the width direction of one flat plate portion 133 b, thereby substantially facing the other flat plate portion 133 a. A butt portion 137 is formed to protrude to a position where it comes into contact with the inner surface of the flat plate portion 133a. The tip end surface of the butted portion 1337 may be joined to the inner surface of the flat plate portion 133a, or may simply be in contact. The same configuration can be adopted for the heat exchange tubes 122b and 121c.

The heat exchange tubes 14 1 a in the embodiment shown in FIG. 12A are opposed to each other at intervals and form two heat exchange medium flow paths 142 between them. 4 3, and folded portions 144 4 a and 144 b bent at both ends in the width direction of one flat plate portion 144 a so as to bend a plurality of times at each end. The parts 144a, 144b are joined by brazing to the corresponding widthwise ends 144b, 144b of the other flat plate 144b (joint 144a , 1 4 6 b). In the folded portions 144a and 144b, the first folded piece 1447a is in close contact with the inner surface of the tube of the flat plate 144a by surface contact, and the subsequent folded piece 1 47 b is folded so as to be in close contact with the preceding folded piece portion 144 a by surface contact. Then, the folded pieces 144b of the folded portions 144a and 144b are brought into surface contact with the corresponding ends 144a and 144b of the other flat plate 144b. They are joined by brazing so that they come into close contact. Such folded portions 144a and 144b are formed by press working.

In the heat exchange tube 14 1 b of the embodiment shown in FIG. 12B, a folded portion 1 488 that is folded only once is formed at the corresponding both ends of the other flat plate portion 144, and the folded portion is formed. 1 4 4 a, 1 4 b and their corresponding folded portions 1 4 8 are denser by surface contact. They are joined by brazing to wear. In the heat exchange tube 14 1 c of the embodiment shown in FIG. 12C, the two flat portions 14 3 a and 14 3 b are each provided with two folded portions 14 4 a at both ends corresponding to each other. , 144b are formed, and the corresponding folded portions are joined by brazing so that they are in close contact with each other by surface contact. As described above, even in a mode in which the tubes are separated from each other before the tube is formed, the number of times of the folded portion and the shape of the corresponding end of the other flat plate portion 144 b can be freely set, and The dimension (flow path height) is accurately determined to the target dimension by the number of folded pieces interposed between the flat portions 144a and 144b. Of course, also in this embodiment, internal dimensions other than those shown in the figure are possible, and according to the target dimensions, the number of folded pieces interposed between the two flat plate parts 144a and 144b, What is necessary is just to decide the number of times of turn in a part.

The heat exchange tube 15 1 in the embodiment shown in FIG. 13 has two flat plate portions 15 3 a and 15 3 b forming a heat exchange medium flow path 15 2 similar to that shown in FIG. 12A. At both ends in the width direction of one of the flat plate portions 15a, there are folded portions 154a and 154b, each of which is bent so that each end is bent a plurality of times. 15 5a, 15 5b are joined by brazing to the corresponding widthwise ends 15 5a, 15 5b of the other flat plate 15 5b (joint 15 6a , 156b). In the present embodiment, the flat plate portion 1553b is bent at the center in the width direction of the one flat plate portion 1553b, thereby substantially facing the other flat plate portion 1553a. A butt portion 157 projecting to a position where it comes into contact with the inner surface of the flat plate portion 153 a is formed on the flat portion. The tip surface of the butted portion 157 may be joined to the inner surface of the flat plate portion 153a, or may simply be in contact.

Generally, each heat exchange tube as shown in Figs. 10 to 13 is temporarily assembled with other heat exchanger parts such as fins and header pipes, joined by furnace brazing, and used as a heat exchanger. Manufactured. Further, as described later, an inner fin may be inserted into the tube for the purpose of improving the pressure resistance and the heat transfer performance. In other words, fins may be bonded to both inside and outside of the tube. In such a case, a brazing material is usually used for brazing, in which a brazing material is attached to either a fin or a tube seal. In this case, brazing material is applied to both sides of the tube shell. It goes without saying that the tube shell can be brazed in a liquid-tight manner using the attached cladding material, but it is possible to use a brazing material that does not clad the brazing material for the fin. When brazing only tube seals, use a brazing material clad on both the inside and outside, use a material clad on one side only, or use a combination of these materials as appropriate. it can.

The heat exchange tubes 12a, 131, 11a, and 151 shown in FIG. 10 to FIG. 13 are manufactured by the method shown in FIG. 14 to FIG. The heat exchange tubes 121b and 121c.111b.141c can be manufactured by the same method.

FIG. 14 shows a method of manufacturing the heat exchange tube 122 a shown in FIG. 10A. First, a flat plate 163 having a predetermined width is formed from a wide flat plate 161 as a material for forming a tube by cutting with an appropriate cutting device 162 or the like. Next, one end in the width direction of one flat plate 163 having a predetermined width is bent and bent twice so as to form a folded portion 125a at the end.

Next, the central portion in the width direction of the flat plate 16 3 is bent toward the upper surface side in FIG. 14 to form a bent portion 124, which faces each other with an interval therebetween, and has a heat exchange medium flow path 1 therebetween. Forming 2 2 Two flat portions 1 2 3 a and 1 2 3 b are formed. Then, the folded portion 1 25 a at the end of the flat plate portion 1 23 a and the end portion 125 b of the flat plate portion 123 b are joined to each other (joined portion 1 26), whereby the configuration shown in FIG. The heat exchange tube 1 2 1a shown in A is completed.

FIG. 15 shows a method of manufacturing the heat exchange tube 13 1 shown in FIG. First, a flat plate 171 having a predetermined width slightly larger than that shown in FIG. 14 is formed from a wide flat plate 161 as a material by cutting with a cutter device 162 or the like. Next, a butt portion 1337 is formed at a predetermined position of the one flat plate 171 by bending. Then, one end in the width direction of the flat plate 171 is bent so as to be folded twice on the same surface side as the butted portion 1337, and a folded portion 135a is formed at the end. Next, the central portion in the width direction of the flat plate 17 1 is bent on the same side as the butt portion 13 37 to form a bent portion 13 34, which faces each other at an interval, and is used for heat exchange medium. Two flat plate portions 1 3 3 a and 1 3 3 b forming the flow path 13 2 are formed. TJ 1370

1 6

Then, the folded portion 1 35 a at the end of the flat plate portion 13 3 a and the end portion 13 5 b of the flat plate portion 13 3 b are joined to each other (joined portion 13 6), whereby FIG. The heat exchange tube 13 1 shown in Fig. 13 is completed.

FIG. 16 shows a method of manufacturing the heat exchange tube 141 a shown in FIG. 12A. First, two flat plates 18 1a and 18 1b having different widths are formed by cutting a wide flat plate 16 1 force spatula as a material and a cutter device 16 2 or the like. Next, folded portions 144a and 144b are formed at both ends of one of the flat plates 181a by bending. Both flat plates 18 1 a and 18 1 b are used as both flat plate portions 14 3 a and 14 3 b, and folded portions 14 4 a and 14 4 b and both ends of the corresponding flat plate portions 1 4 5a. By positioning the 1145b so that they face each other and joining them together (joints 1446a and 1146b), the two flat plate portions 1 5 3 shown in Fig. 12A are obtained. The heat exchange tubes 14 1 a having the heat exchange medium flow paths 14 2 therein are completed by a and 15 3 b.

FIG. 17 shows a method of manufacturing the heat exchange tube 15 1 shown in FIG. First, two flat plates 191a and 191b are formed from a wide flat plate 161 as a raw material by cutting with a cutting machine 162. Next, an abutting portion 157 is formed by bending at the center in the width direction of one of the flat plates 191 b. On both ends of the other flat plate 191a, each end is bent so as to be bent a plurality of times to form folded portions 154a and 154b. The folded portions 154a and 154b are joined to the corresponding widthwise opposite ends 155a and 155b of the other flat plate 191b by brazing (joining portion 156a). Thus, the heat exchange tube 15 1 having the heat exchange medium flow path 15 2 therein as shown in FIG. 13 is completed.

In the heat exchanger tube manufactured and configured as described above, similar to the heat exchanger tube shown in FIGS. At least, the folded part formed at the width direction end of one flat part can be joined to the corresponding width direction end of the other flat part in a surface contact state, resulting in a sufficiently large bonding area and high Bonding strength can be ensured, and high pressure resistance can be achieved. The folded portion is bent a plurality of times in a direction opposite to each other, and is formed so that the folded pieces are overlapped in surface contact. The high strength of the tube itself is also ensured, and the high joint strength is ensured by the joining surface in the surface contact state as described above, so that the tube as a whole can achieve higher pressure resistance.

In addition, since the folded portion formed at the end in the width direction of the flat plate can be formed by press working, the conventional roll working is not required, and the processing cost, and thus the production cost of the tube and the heat exchanger, are reduced. Significant reduction is possible. In addition, since roll processing is not performed, correction after processing is not required, and the incidence of defective products can be significantly reduced, making it easier to manufacture and further reducing manufacturing costs.

In addition, the folded portion is formed by being bent so that it is folded a plurality of times in the opposite direction, and the inner size of the tube can be substantially freely and accurately determined by the number of times of the folded portion. The degree of freedom is greatly increased. The inner dimensions of this tube are more accurately determined by the fact that the folded pieces are in contact with each other, and the first folded piece and the flat surface of the inner surface of the tube are in surface contact with each other. The size is determined to correspond to the number of pieces. Therefore, the inner dimensions of the tube to be formed can also be accurately and accurately determined to the target dimensions, and a tube having a desired inner dimension can be easily obtained.

In addition, since there is no brazing portion at the center in the width direction of the tube, there is no possibility of a failure in the rotation of the flux. Also, the butted portion for reinforcing the tube can be easily formed by bending one flat plate portion itself, so that a high-strength tube structure can be easily realized.

Furthermore, in the structure with the butted part, when the core part 6 is fixed with a jig, it is generated due to the difference in the coefficient of thermal expansion between the core part and the brazing jig. High resistance to deformation and displacement. As a result, it is possible to effectively prevent deformation of the tube and occurrence of defective brazing. Therefore, it is possible to manufacture a high-performance heat exchanger that has been reliably brazed and has no fear of leakage. In the description of these manufacturing methods, the butted portion is formed before the formation of the folded-back portion, but it can be formed after the formation of the folded-back portion. Further, the following structure can be further added to the heat exchanger tube having the structure shown in FIGS. 2 to 5 and FIGS. 10 to 13 described above. The following additional configuration describes the heat exchanger tube with the structure shown in Fig. 2 and Fig. 10A, but is shown in Figs. 3 to 5 and Fig. 10B, C, Fig. 11 to Fig. 13. The same can be applied to a tube having a structure.

First, in the heat exchange tube 201 shown in FIGS. 18 and 19, the heat exchange medium flow path 200 3 formed between the flat plate portions 202 a and 202 b of the tube 201. In addition, a corrugated inner fin 204 is provided, and the inner fin 204 divides the flow path 203 into a plurality. The structure of the inner fin 204 is not particularly limited, and a structure other than a waveform is also applicable. Such an inner fin 204 can be inserted after forming the tube 201.

In the heat exchange tube 201 having such a configuration, in addition to the functions and effects described with reference to FIG. 2 or FIG. 10A, the temperature of the tube 201 is made uniform, and the tube 201 The heat exchange performance is further improved.

In the heat exchange tubes 211 shown in FIGS. 20A, 20B and 21A, 21B, the two flat portions 2 12a. A plurality of protruding portions 21 13 protruding toward the inside of the tube are provided, and the protruding portions 2 13 are arranged to face each other, and their end surfaces are in contact with each other. Each protruding portion 21 3 can be easily formed by embossing the flat plate material before forming the tube, and the tube may be formed after forming each protruding portion 2 13.

In the heat exchange tube 211 having such a configuration, in addition to the operation and effect described with reference to FIG. 2 or FIG. 10A, the mixing effect of the heat exchange medium flowing through the flow passage by the protrusions 21 is provided. As a result, the temperature uniformity and heat transfer are promoted, and the heat exchange performance of the tubes 211 is further improved.

Note that the protruding portion 21 3 may be provided only on one flat plate portion, and the distal end surface of the protruding portion 21 3 may be brought into contact with the inner surface of the other opposing flat plate portion.

In addition, the heat exchange tubes 22 shown in Figures 22A and 22B and Figures 23A and 23B In 1, a plurality of grooves 222 a and 222 b extending obliquely in the direction intersecting with each other are formed in each of the opposing surfaces of the flat plate portions 222 2 a and 222 b. For example, as shown in FIG. 24, the grooves 2 23 a and 22 3 b are formed on the flat material 2 24 before being formed on the tube 22 1 and on the tube 2 21 when formed on the tube 2 21. Grooves 22 3 a and 22 3 b may be carved so as to extend in the direction intersecting with each other as shown in FIG.

In the heat exchange tube 22 1 having such a configuration, in addition to the operation and effect described with reference to FIG. 2 or FIG. 10A, the heat exchange tube 22 1 Since the mixing effect of the heat exchange medium is improved, the temperature can be made uniform and the heat transfer can be promoted, and the heat exchange performance of the tube 221 can be further improved. Further, in the present invention, for example, as shown in FIGS. 25 and 26, the flat plate portions 23a and 23b are placed outside the tube so that the center in the width direction becomes the top. The tube 23 may be configured to bulge toward the tube. With this configuration, the pressure resistance of the tube 23 1 can be improved. The swelling amount S may be a very small amount.

Note that the heat exchanger tube according to the present invention is not limited to the type of heat exchanger as shown in FIG. 1, but is applicable to any type of heat exchanger. It is particularly suitable for heat exchangers for vehicles, for example, heaters, condensers, evaporators, etc. for radiators and air conditioners, and also for coolers, etc.

Industrial availability

According to the present invention, a tube for a heat exchanger having high joining strength and pressure resistance and high design flexibility can be easily and inexpensively manufactured. In addition, it is possible to remove anxiety such as poor brazing due to poor flux rotation, and to improve the deformation resistance of the tube by forming a butted portion. Therefore, such tubes for heat exchangers having excellent performance are extremely useful for heat exchangers for vehicles and the like.

Claims

Scope of demand

1. Two flat portions facing each other and forming a flow path for a heat exchange medium therebetween, and at least one of the flat portions formed at least in one widthwise end by folding the ends. A folded portion having an integral multiple of the thickness of a plate forming the end portion, wherein the folded portion and a corresponding widthwise end portion of the other flat plate portion are joined to each other. And the heat exchanger tube.

2. There is a bent portion integrally connecting the two flat portions at one widthwise end of the two flat portions, and the folded portion is formed at the other widthwise end of each of the two flat portions. 2. The heat exchanger tube according to claim 1, wherein the folded portions are joined to each other.

3. The tube for a heat exchanger according to claim 1, wherein the folded portions are respectively formed at both widthwise ends of the two flat plate portions, and the corresponding folded portions are joined to each other.

4. The heat exchanger tube according to claim 1, wherein the folded portion is formed by folding back at least one width direction end of at least one flat plate portion.

5. The folded portion is folded so that the first folded portion comes into surface contact with the inner surface of the tube of the flat plate portion, and the subsequent folded portion comes into surface contact with the preceding folded portion. Item 4. Tubes for heat exchangers.

6. The heat exchanger tube according to claim 1, wherein the folded portion is formed by press working.

7. At the center in the width direction of one of the flat portions, the one flat portion is bent so as to protrude toward the other flat portion to a position substantially in contact with the other flat portion. 2. The heat exchanger tube according to claim 1, wherein a butt portion is formed.

8. The heat exchanger tube according to claim 1, wherein the folded portion is joined to a corresponding widthwise end of the other flat plate by brazing.

9. The heat exchanger tube o according to claim 1, wherein an inner fin is provided between the flat plate portions.

10. At least one of the flat plate portions is provided with a plurality of protrusions projecting inward of the tube, and the protrusions facing each other or the flat plate portion provided with the protrusions and the protrusions are provided. The heat exchanger tube according to claim 1, wherein an inner surface of the flat plate portion facing the butt is abutted against each other.

11. The heat exchanger tube according to claim 1, wherein grooves that extend in directions intersecting each other are provided on each of the opposing surfaces of the flat plate portion.

12. The heat exchanger tube according to claim 1, wherein the flat plate portion bulges outward from the tube such that a substantially central portion in a width direction of the flat portion is a vertex.

13. A heat exchanger comprising the heat exchanger tube according to any one of claims 1 to 12.

14. The heat exchanger of claim 13, wherein tubes and fins are alternately arranged.

15 (a) A folded part having a thickness equal to an integral multiple of the thickness of the plate forming the end by folding the end at at least one end in the radiation direction of one flat plate having a predetermined width. And (b) bending the central portion in the width direction of the flat plate so that the folded portion is on the inner side to form two flat plate portions forming a heat exchange medium flow path therebetween (c). ) At least the folded portion formed at the end of one flat plate portion corresponds to the other flat plate portion. A method for producing a tube for a heat exchanger, characterized in that the tube is joined to an end of the heat exchanger.

16. (A) An integral multiple of the thickness of the plate forming each end by folding back each end at the width direction both ends of at least one of the two flat plates each having a predetermined width (B) joining a folded portion of a flat plate having folded portions formed at both ends in the width direction and a corresponding end of the other flat plate to each other. How to manufacture tubes for heat exchangers.

17. The method for manufacturing a tube for a heat exchanger according to claim 15 or 16, wherein the folded portion is formed by bending a plurality of ends of the flat plate in the width direction.

18. The heat exchanger according to claim 17, wherein the folded portion is folded so that the first folded portion comes into surface contact with the flat plate and the subsequent folded portion comes into surface contact with the preceding folded portion. Tube manufacturing method.

19. The method of manufacturing a heat exchanger tube according to claim 15, wherein the folded portion is formed by press working.

20. A position where one of the two flat plate portions forming the tube is bent into the one flat plate portion itself so as to substantially contact the other flat plate portion toward the other flat plate portion. The method for producing a tube for a heat exchanger according to claim 15 or 16, wherein a butt portion protruding up to is formed.

21. The method _c for manufacturing a heat exchanger tube according to claim 15 or 16, wherein the folded portion is joined to a corresponding end of the flat plate portion facing the folded portion by brazing.

22. The method for producing a tube for a heat exchanger according to claim 15 or 16, wherein an inner fin is interposed between two flat plate portions forming the tube.

23. The method for manufacturing a heat exchanger tube according to claim 15 or 16, wherein a plurality of protrusions protruding inward of the tube are formed on the flat plate when the tube is formed.

24. The heat exchanger tube according to claim 15 or 16, wherein grooves extending in directions intersecting with each other at the time of forming the tube are formed on surfaces of the respective flat plate portions which are surfaces that face each other when the tube is formed. Production method.