WO2005071340A1

WO2005071340A1 - Flat tube for heat exchanger, heat exchanger using the flat tube, and method of molding the flat tube for the heat exchanger

Info

Publication number: WO2005071340A1
Application number: PCT/JP2004/017913
Authority: WO
Inventors: Akihiko Takano
Original assignee: Valeo Thermal Systems Japan Corporation
Priority date: 2004-01-27
Filing date: 2004-12-02
Publication date: 2005-08-04
Also published as: EP1710525A1; EP1710525A4; JP2005214459A

Abstract

A flat tube for a heat exchanger capable of reducing the outside dimensions of the heat exchanger and also commonizing the parts thereof, a heat exchanger using the flat tube, and a method of manufacturing the flat tube. In the flat tube (5, 6) formed in flat tube shape with both ends opened to the outside and fluid flow passages formed therein, areas near the opened end parts (13) and (14) are twisted, and the opened end parts (13) and (14) are inserted into tube insert holes (7), (8), and (12) extended along the centerlines of header pipes (2), (3), and (4). The opened end parts (13) and (14) of the flat tube (5, 6) are formed offset relative to the longitudinal centerline of the flat tube. The offset amount is set so that the opening end parts (13) and (14) are aligned with the side edges of the flat tube (5, 6). Thus, the outside dimensions of the heat exchanger can be reduced and the parts thereof can be commonized.

Description

Specification

Flat tube for heat exchanger, heat exchanger using the same, and method of forming flat tube for heat exchanger

Technical field

The present invention relates to a heat exchange flat tube formed into a flat tube having both ends opened and having a passage therein, and having an open end inserted into a tube insertion hole formed in a header pipe. The present invention relates to a flat tube for heat exchange in which the vicinity of an end is twisted, a heat exchanger using the flat tube, and a method for forming the flat tube for a heat exchanger.

Background art

[0002] In heat exchange of high-pressure specification having a header pipe and a flat tube inserted and joined to the header pipe, it is necessary to minimize the diameter of the header pipe as much as possible in order to secure pressure resistance. There is. For this reason, the flat tube inserted and joined to the header pipe is twisted approximately 90 degrees in the vicinity of the open end so that the open end is aligned with the longitudinal direction of the header pipe, and axially attached to the peripheral surface of the header pipe. A configuration has been considered in which a tube insertion hole extending along the tube is formed, and the open end of the flat tube is inserted and joined to the tube insertion hole (Patent Document 1). Further, in such a configuration, a configuration in which an opening portion is offset with respect to a center line in a longitudinal direction of a flat tube has been considered (see Patent Document 2). Patent Document 1: Japanese Patent Publication No. 2002-521644

Patent Document 2: European Patent Publication EP0845648A2

Disclosure of the invention

Problems to be solved by the invention

[0003] However, if the offset amount of the twisted open end of the flat tube is insufficient in the above-described configuration, the header pipe is provided adjacent to the flat tube, and the flat tube is arranged in parallel. In the heat exchange provided, in order to insert the open end into the tube insertion hole of the header pipe, the flat tubes arranged side by side must be provided apart from each other. The size of the replacement part increases. Conversely, if the offset amount at the opening end becomes too large, the interval between adjacent header pipes must be increased, and Inconvenience that the external dimensions become large in this way occurs.

[0004] Further, if the offset amount of the opening end is changed each time to adjust the external dimensions of the heat exchanger, parts cannot be shared, and the manufacturing process and the assembling process become complicated. There are inconveniences. Furthermore, in order to form such a flat tube, a forming step for twisting and offsetting the open end is required, and thus it is an urgent task to establish a forming method suitable for mass production.

[0005] Therefore, in the present invention, it is intended to provide a heat exchange flat tube capable of reducing the outer dimensions of the heat exchanger and sharing components, and further providing such a flat tube. The main issues are to provide heat exchange using tubes and to provide a method for forming flat tubes suitable for mass production.

Means for solving the problem

[0006] In order to achieve the above object, a flat tube for heat exchange according to the present invention is formed in a flat tube having both ends opened and a fluid passage therein, and the vicinity of the open end is twisted. And the open end of the flat tube is offset from the longitudinal center line of the flat tube in a configuration in which the open end is inserted into a tube insertion hole extending along the center line of the header nose. The offset amount is set so as to make the opening end portion coincide with the side edge of the flat tube (claim 1).

[0007] Therefore, when two flat tubes are arranged side by side, in a configuration in which the header noises are adjacent to each other, the two flat tubes are arranged side by side with the offset open ends facing outward, so that the gap between the open ends is reduced. The distance can be ensured, and the opening end can be set in a state where it is not too far away, so that the header pipe can be arranged close to the header pipe. In addition, when two flat tubes are connected side by side to a common header pipe, even if the flat tubes are arranged side by side with the offset open ends facing inward, the open ends can be brought close to each other. It is possible to minimize the diameter of the common header pipe.

[0008] A tube formed into a flat tube having both ends opened and having a fluid passage therein, a portion near the opening end being twisted, and an opening end extending along the center line of the header pipe. In the flat tube for heat exchanger inserted into the insertion hole, the opening of the flat tube After the end is offset from the longitudinal center line of the flat tube, the dimension of the torsion along the longitudinal direction of the flat tube is set to at least 1.0 times the width of the flat tube, and 1. It is preferable to set the range to 3 times or less in order to maintain the heat exchange performance while maintaining the durability (claim 2).

[0009] The heat exchange is formed as a header pipe, a flat tube having both ends opened and having a fluid passage therein, and an open end inserted into a tube insertion hole formed in the header pipe. And a fin interposed between adjacent flat tubes, the tube insertion hole is formed as an elongated hole extending along the center line of the header pipe, The vicinity of the open end of the flat tube is twisted and the open end is offset with respect to the longitudinal center line of the flat tube, and the amount of this offset corresponds to the side edge of the flat tube. By setting the amount to be reduced, the size can be reduced (claim 3).

[0010] More specifically, the header pipe is provided adjacent to the first header pipe, the relay header pipe provided opposite thereto, and the first header pipe, and is provided opposite to the relay header pipe. A plurality of first flat tubes provided so as to communicate the first header pipe and the relay header noise, and a relay header. A plurality of second flat tubes provided so as to communicate the pipe and the second header pipe, wherein the first flat tube is a tube insertion hole of the first header pipe. The second flat tube is also offset from the side edge of the second flat tube to be moved away, and the open end inserted into the tube insertion hole of the relay header pipe is inserted into the second flat tube. tube The second flat tube has an open end inserted into a tube insertion hole of the second header pipe, and the second flat tube has a side on which the first flat tube force moves away from the first flat tube force. It is preferable to provide an offset at the edge, and to offset the opening end inserted into the tube insertion hole of the relay header pipe to a side edge close to the first flat tube (claim 4). With such a configuration, it is possible to reduce the size of the heat exchange of the alternating current.

[0011] Further, in the method of manufacturing a flat tube for heat exchange according to the present invention, the flat tube having both ends opened and having a fluid passage therein is formed, and the vicinity of the opening end is twisted and opened. Molding of a flat tube for heat exchangers with the mouth end inserted into a tube insertion hole extending along the center line of the header pipe and offset from the center line in the longitudinal direction of the flat tube. According to the method, the open end of the flat tube and a part separated by a predetermined distance from it are sandwiched by the chuck member, and the chuck member sandwiching the open end is rotated around an axis in the same direction as the longitudinal direction of the flat tube. It may be made to slide in the offset direction while making it move (claim 5).

[0012] Further, as a method of forming a flat tube for a heat exchanger, a flat tube having both ends opened and having a fluid passage therein is formed, and the vicinity of the opening end is twisted so that the opening end is formed into a header pipe. The method for molding a flat tube for a heat exchanger, wherein the flat tube is inserted into a tube insertion hole extending along the center line of the flat tube and offset from the center line in the longitudinal direction of the flat tube. The opening end portion and a portion separated by a predetermined distance from the opening end portion are sandwiched by a chuck member, and the chuck member sandwiching the opening end portion is slid in the sandwiching direction. (Claim 6), the portion of the flat tube that is separated from the open end by a predetermined distance is sandwiched by the chuck member, and then the open end is closed by another chuck. The chucking member may be displaced in the direction of being sandwiched by the member, and then the chuck member sandwiching the open end may be rotated about the longitudinal centerline of the flat tube (claim 7). The open end of the tube and a portion separated by a predetermined distance from the open end are sandwiched by a chuck member, and the chuck member sandwiching the open end is rotated around an axis in the same direction as the longitudinal direction of the flat tube. It may be slid in the offset direction (claim 8).

[0013] Here, when the chuck member sandwiching the open end of the flat tube is rotated around an axis in the same direction as the longitudinal direction of the flat tube, the chuck member sandwiches the opening end portion at a predetermined distance. Even if the torsion portion is formed to be small in close proximity to the chuck member (claim 9), a predetermined distance is provided between the chuck member and the flat tube provided at a position separated by a predetermined distance from the open end of the flat tube. A clearance may be provided (Claim 10), and a portion separated by a predetermined distance from the opening end portion of the flat tube may be sandwiched by a pair of rollers instead of the chuck member. Section 11). [0014] Further, the chuck member that sandwiches the open end portion of the flat tube and the chuck member that is provided at a portion separated by a predetermined distance from the chuck member are subjected to R-shaped chamfering at the corners of the sandwiching portion on the side facing each other, The chuck member may be prevented from biting into the flat tube (claim 12). In this case, the chamfer radius R is preferably set so that R≥0.5t with respect to the plate thickness t of the flat tube (claim 13).

The invention's effect

[0015] As described above, in the present invention, a flat tube having both ends opened and having a fluid passage therein is formed, the vicinity of the opening end is twisted, and the opening end is the center line of the header pipe. In the heat exchange flat tube inserted into the tube insertion hole extending along the length of the flat tube, the open end of the flat tube is offset from the longitudinal center line of the flat tube, and this offset amount is set. Is made to match the opening end with the side edge of the flat tube, so that the external dimensions of the heat exchange can be reduced, and the parts can be used in common. It is possible to avoid the complexity of the process and the assembly process.

[0016] Furthermore, the twisted open end of the flat tube is provided offset from the longitudinal center line of the flat tube, and the twist width is at least 1.0 times the width of the flat tube, and 1. By setting the range to three times or less, it becomes possible to reduce the useless area without fins while ensuring the durability of the torsion portion.

In order to mold the flat tube described above, the vicinity of the open end is twisted around an axis in the same direction as the longitudinal direction of the flat tube, and the open end is aligned with respect to the central axis in the longitudinal direction of the flat tube. Force that needs to be offset When these processes are performed using two chuck members, the open end of the flat tube and a part separated by a predetermined distance from it are sandwiched by the chuck member, and the open end is sandwiched. If the chuck member is slid in the offset direction while rotating about the axis in the same direction as the longitudinal direction of the flat tube, the material is deformed in the shortest distance, which is advantageous for the amount of deformation.

Further, the opening end of the flat tube and a portion separated by a predetermined distance from the opening end are sandwiched by a chuck member, and the chuck member sandwiching the opening end is slid in the offset direction. When rotating around the longitudinal centerline, the flat tube A portion separated by a predetermined distance from the opening end is sandwiched by the chuck member, and then the opening end is sandwiched while being displaced in the offset direction by another chuck member. When rotating around the longitudinal centerline of the flat tube, or by holding the open end of the flat tube and a part separated by a predetermined distance from it with the chuck member, and holding the chuck member with the open end in between. When the flat tube is rotated around the longitudinal direction and then slid in the offset direction after applying force, the movement of the chuck member can be simplified, and the mechanism can be simplified. It becomes possible.

[0019] Further, the chuck member sandwiching the open end portion of the flat tube may be used for rotating the open end portion about an axis in the same direction as the longitudinal direction of the flat tube. In addition, by bringing the portion separated by a predetermined distance from the opening end close to the chuck member that sandwiches the material, the amount of elongation of the material can be reduced, and the inconvenience of the material being stretched and torn can be reduced. In addition, it is possible to secure a large mounting area for the heat exchange fins by reducing the torsion portion that does not exchange heat, and it is possible to increase the heat exchange area.

[0020] A predetermined clearance is provided between the flat tube and a chuck portion provided at a predetermined distance from the open end portion of the flat tube, or the flat tube is sandwiched by a pair of rollers instead of the chuck portion. By doing so, the elongation of the torsion portion can be absorbed by the entire flat tube.

[0021] Furthermore, the flattening of the flattened tube is performed by chamfering the corners of the chucking member sandwiching the open end portion of the flat tube and the chucking member sandwiching the portion separated by a predetermined distance from the chucking member on the opposing sides into an R shape. It is possible to prevent the chuck member from biting into the tube and to avoid damage to the twisted portion.

Brief Description of Drawings

FIG. 1 shows a schematic configuration of a heat exchanger according to the present invention. FIG. 1 (a) is a plan view of the heat exchanger, and FIG. 1 (b) is a plan view of the heat exchanger. FIG. 1C is a front view of the heat exchanger, FIG. 1C is a diagram showing first and second header pipes, and FIG. 1D is a diagram showing a relay header pipe. [FIG. 2] FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 (b), showing a relationship between a header pipe and a flat tube.

[FIG. 3] FIG. 3 is a diagram showing a single flat tube of the heat exchanger, FIG. 3 (a) is a diagram of the flat tube viewed from above, and FIG. 3 (b) is a diagram of the flat tube in the horizontal direction. FIG.

FIG. 4 (a)-(c) are views showing a first forming step of forming a torsion formed near the open end of the flat tube.

FIG. 5 (a)-(d) are views showing a second forming step of forming a torsion formed near the open end of the flat tube.

6 (a) -1 (d) are views showing a third forming step of forming a torsion portion formed near the open end of the flat tube.

7 (a)-(d) are views showing a fourth forming step of forming a torsion formed near the opening end of the flat tube.

FIG. 8 (a)-(c) are views showing a fifth forming step of forming a torsion formed near the open end of the flat tube.

[FIG. 9] FIG. 9 shows an example in which a predetermined clearance 30 is provided between the second chuck member and the flat tube in the step of forming a torsion formed near the open end of the flat tube. FIG.

FIG. 10 is a view showing an example in which a pair of rollers is used in place of the second chuck member in the step of forming a torsion formed near the opening end of the flat tube. is there

[FIG. 11] FIG. 11 is a diagram showing an example in which the corners of the sandwiching portions of the chuck portions 21, 22 forming the torsion portions 15, 16 are chamfered in an R shape.

FIG. 12 is a characteristic diagram showing a relationship between a chamfer radius and a torsion width.

FIG. 13 is a characteristic diagram showing a relationship between a torsion width, a waste area of heat exchange, and a risk of leakage.

Explanation of symbols

1 heat exchange ^^

2 First header pipe 3 Second header pipe

4 Relay header pipe

5, 6 Flat tube

13, 14 Open end

15, 16 Torsion

17 Fins

BEST MODE FOR CARRYING OUT THE INVENTION

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

[0025] In Figs. 1 and 2, the heat exchanger 1 has a refrigeration in which a high-pressure refrigerant such as a CO refrigerant is sealed.

2

It is used as heat exchange for the cycle, and is provided opposite the first and second header pipes 2, 3 adjacent to each other and the first and second header pipes 2, 3. The first header pipe 2 and the relay header pipe 4 are connected by a plurality of first flat tubes 5, and the second header noise 3 and the relay header pipe 4 are plural. The second flat tubes 6 communicate with each other.

The first and second header pipes 2 and 3 are formed by fitting tube mounting plates 2b and 3b into slits 4 and 5 formed on side surfaces of pipe constituent members 2a and 3a having a circular cross section. Both ends in the longitudinal direction are closed by lids 2c and 3c inserted through notches 6 of the pipe components 2a and 3a. As shown in Fig. 1 (c), the tube insertion plates 7, 8 consisting of elongated holes extending in the longitudinal direction are aligned in a row on each tube mounting plate 2b, 3b. A plurality is formed.

On the other hand, the relay header pipe 4 is formed into a pipe shape by fitting the tube mounting plate 4b into a slit portion 9 formed on the side surface of a pipe component member 4a having the same circular cross section. Both ends in the longitudinal direction are closed by a lid 4c inserted from the notch 10 of the pipe component 4a, and the diameter of the pipe component 4a is smaller than the diameters of the first and second header nose 2 and 3. The width of the tube mounting plate 4b is also larger than the width of the tube mounting plates 2b, 3b of the first and second header pipes 2, 3. As shown in FIG. 1 (d), the tube mounting plate 4b is formed with a plurality of tube insertion holes 12 which are elongated holes extending in the longitudinal direction and are aligned in two rows. The

The first flat tube 5 and the second flat tube 6 are open at both ends to form a fluid passage therein, and as shown in FIG. 3, open ends 13, 14 on both sides in the longitudinal direction. Is twisted approximately 90 degrees around the axis in the same direction as the longitudinal direction. The open ends 13 and 14 are provided at positions offset with respect to the longitudinal center line of the flat tubes, and the amount of offset is adjusted so that the open ends match the side edges of the flat tubes 5 and 6. And Further, one open end in the longitudinal direction of the flat tubes 5 and 6 is offset to the side opposite to the other open end, and is formed point-symmetric with respect to the center of the flat tubes.

The first flat tube 5 has one open end 13 inserted into the tube insertion hole 7 of the first header pipe 2, and the inserted open end 13 is inserted into the second flat tube 6. The other open end 14 is inserted into the tube insertion hole 12 of the relay header pipe 4 and the inserted open end 14 is inserted into the second flat tube. Offset to side edge close to 6. The second flat tube 6 has one open end 14 inserted into the tube insertion hole 8 of the second header tip 3, and the inserted open end 14 is remote from the first flat tube 5. It is offset to the side edge which is weak, and the other open end 13 is inserted into the tube insertion hole 12 of the relay header pipe 4, and the inserted open end 13 is brought close to the first flat tube 5. Offset to the side edge.

[0030] Between the first flat tubes 5 and between the second flat tubes 6, corrugated fins are formed on flat portions excluding the torsion portions 15, 16 formed near the open ends on both sides. In the flat tubes on both sides, side plates 18 having a U-shaped cross section are provided on the flat portions via fins 17. The fins interposed between the first flat tubes 5 and the fins interposed between the second flat tubes 6 may be separate or integrally formed.

Therefore, the fluid that has flowed into the first header pipe 2 is distributed to and flows into the first flat tube 5, heat exchanges with the air passing between the fins 17, and then collects in the relay header pipe 4. Can be After that, it makes a U-turn in the relay header pipe 4 and distributes and flows into the second flat tube 6, further heat exchanges with the air passing between the fins 17, and is collected in the second header pipe 3. It flows out of the second header pipe 3. Therefore, the flow of the refrigerant The first flat tube 5 and the second flat tube 6 can have a counterflow, and the wind can pass from the second flat tube 6 side, so that the order of the refrigerant flowing through the flat tubes and the air The flow can be countercurrent.

[0032] The open ends 13, 14 of the flat tubes 5, 6 are offset so as to coincide with the side edges of the flat tubes 5, 6, so that the first and second header pipes 2, The third side is offset so as to coincide with the outer side edge, and the relay header noise 4 side is offset so as to coincide with the inner side edge). In the header pipes 2 and 3, the open end 13.14 of the flat tube 5.6 can be inserted into the tube insertion hole without separating it, so that it can be adjacent to the header pipe 4 and the relay header pipe 4. In this case, the open ends 13, 14 of the first and second flat tubes 5, 6 can be brought sufficiently close to each other, so that the diameter can be reduced. Therefore, it is possible to reduce the size of the heat exchange of the counterflow, and the first and second flat tubes can use the same flat tube. The manufacturing process and the assembling process can be prevented from being complicated, which is suitable for mass production.

By the way, in order to realize the above-described twist near the open end of the flat tube and the offset of the open end, it is necessary to establish a molding method suitable for mass production. Use a method.

FIG. 4 shows a first forming method. The forming method shown here is shown in FIG. 4 (a) for a flat tube (5 or 6) cut to a predetermined size. As described above, the opening end (13 or 14) and the portion 20 separated from the opening end by a predetermined distance are sandwiched between the first and second chuck members 21 and 22, and as shown in FIG. Then, the first chuck member 21 sandwiching the opening end (13 or 14) is slid in the offset direction while rotating about the axis in the same direction as the longitudinal direction of the flat tubes 5 and 6, and as shown in FIG. The state shown, that is, twisting the vicinity of the open end (13 or 14) by about 90 degrees and making the open end (13 or 14) coincide with the side edge of the flat tube (5 or 6) I do. The twisting step and the offsetting step are performed simultaneously, and the speed of the movement of each step is adjusted so that each movement starts and ends at the same time.

Therefore, according to such a molding method, the flat tube (5 or 6) has an open end (13 Or, in the vicinity of 14), the deformation due to torsion and the deformation due to offset are performed simultaneously, so that the deformation of the material at the torsion portion (15 or 16) is performed at the shortest distance, and the amount of deformation is not wasted.

FIG. 5 shows a second molding method. The molding method shown here is shown in FIG. 5 (a) for a flat tube (5 or 6) cut to a predetermined size. As described above, the opening end (13 or 14) and the portion 20 separated from the opening end by a predetermined distance are sandwiched between the first and second chuck members 21 and 22, and as shown in FIG. Then, slide the first chuck member 21 across the opening end (13 or 14) in the direction of sandwiching, and then, as shown in FIG. 5 (c), the longitudinal direction of the flat tube (5 or 6). Rotate around the center line of the axis, and twist the state shown in Fig. 5 (d), that is, around the open end (13 or 14) by about 90 degrees, and flatten the open end (13 or 14). Form a condition aligned with the side edge of the tube (5 or 6).

Therefore, according to such a molding method, even after the first chuck member 21 is slid, the flat tube (5 or 6) is rotated about the longitudinal center line as an axis. Thus, the movement of the chuck member 21 can be simplified, and the mechanism can be simplified.

FIG. 6 shows a third molding method. The molding method shown here is shown in FIG. 6 (a) for a flat tube (5 or 6) cut to a predetermined size. As shown in FIG. 6 (b), the portion 20 which is separated by a predetermined distance from the opening end (13 or 14) is sandwiched by the second chuck member 22, and the force for sandwiching the first chuck member 21 is formed. The first chuck member 21 is inserted into the first chuck member 21 by displacing the opening end (13 or 14) in the direction of sandwiching the first chuck member 21, and then the first chuck member 21 is flattened as shown in FIG. 6 (c). Rotate around the longitudinal center line of (5 or 6) as an axis, twist about 90 degrees near the open end (13 or 14) as shown in Fig. 6 (d), and open the open end. (13 or 14) is made to coincide with the side edge of the flat tube (5 or 6).

[0039] Therefore, according to such a molding method, the first chuck member 21 is displaced by using the force for pinching the opening end (13 or 14), and then the first chuck member 21 is flattened. The rotation of the chuck (5 or 6) about the longitudinal center line is used to form an offset state, so that the movement of the chuck members 21, 22 can be simplified, and the mechanism can be simplified. It can be simple.

FIG. 7 shows a fourth molding method. The molding method shown here is shown in FIG. 7 (a) for a flat tube (5 or 6) cut to a predetermined size. As described above, the opening end (13 or 14) and the portion 20 separated by a predetermined distance from the opening end are sandwiched between the first and second chuck members 21 and 22, and as shown in FIG. Then, the first chuck member 21 sandwiching the open end (13 or 14) is rotated about the longitudinal center line of the flat tube (5 or 6), and thereafter, as shown in FIG. 7 (c). As described above, the first chuck member 21 is slid in the offset direction, and the state shown in FIG. 7D, that is, the vicinity of the opening end (13 or 14) is twisted by about 90 degrees, and the opening end (13 Or, form a state where 14) is aligned with the side edge of the flat tube (5 or 6).

Therefore, according to such a molding method, the first chuck member 21 is slid after being rotated about the longitudinal center line of the flat tube (5 or 6) as an axis. The movement of the members 21 and 22 can be simplified, and the mechanism can be simplified.

FIG. 8 shows a fifth forming method. The forming method shown here is shown in FIG. 8 (a) for a flat tube (5 or 6) cut to a predetermined size. As described above, the opening end (13 or 14) and the portion 20 separated from the opening end by a predetermined distance are sandwiched between the first and second chuck members 21 and 22, and as shown in FIG. Then, the first chuck member 21 sandwiching the open end (13 or 14) is slid in the offset direction while rotating about the axis in the same direction as the longitudinal direction of the flat tube (5 or 6). The first chuck member 21 is brought close to the second chuck member 22 while performing a proper operation, and the state shown in FIG. 8C, that is, the vicinity of the open end (13 or 14) is twisted by about 90 degrees, A state where the open end (13 or 14) is aligned with the side edge of the flat tube (5 or 6) is formed. The twisting step and the offsetting step are performed simultaneously, and the speed of the movement of each step is adjusted so that each movement starts and ends at the same time.

Therefore, according to such a molding method, the amount of elongation of the material can be reduced, and the inconvenience of the material being stretched and torn can be reduced. In addition, since the size (torsion width L) of the torsion portions 15 and 16 that do not exchange heat can be reduced, it is possible to secure a large mounting area for the fins 17 of the heat exchange ^ 1 and increase the heat exchange area. It becomes possible. When twisting the open ends 13, 14 around the axis in the same direction as the longitudinal direction of the flat tubes 5, 6, the step of bringing the first chuck member 21 close to the second chuck member 22 includes: It may be adopted in any of the configurations described above.

Further, in the above-described configuration, the second chuck member 22 has a configuration in which the portion 20 that is separated by a predetermined distance from the open end portions 13 and 14 of the flat tubes 5 and 6 is configured as shown in FIG. As shown in FIG. 10, a predetermined clearance 30 may be provided between the second chuck member 22 and the flat tubes 5 and 6, or as shown in FIG. In place of, it may be sandwiched by a pair of rollers 31.

According to such a configuration, since the portion 20 that is a predetermined distance from the opening ends 13 and 14 is not pinched by the chuck, the amount of elongation due to the twisting and offset of the flat tubes 5 and 6 is reduced. It is possible to absorb the whole tube, and it is possible to avoid thinning due to elongation of the material and breakage at the chuck portion.

Further, in the above-described chuck portions 21 and 22, it is preferable that the corners of the sandwiching portions on the side where the torsion portions 15 and 16 are formed be chamfered in an R shape as shown in FIG. Here, the radius R of the chamfer may be set so that R≥0.5t with respect to the plate thickness t of the flat tube. When the torsion width increases, the chuck does not bite even if the chamfer radius is reduced, but when the torsion width (dimension of the torsion portion along the longitudinal direction of the flat tube) L (shown in Fig. 3) decreases, the chamfer radius decreases. If not, the chuck portions 21 and 22 will bite, causing breakage and cracking of the chuck portion. Therefore, as shown in Fig. 12, there is a limit that the torsion width L must be increased if the chamfer radius is reduced.However, the chamfer radius R is set within the above range. This makes it possible to prevent the torsion portions 15 and 16 from breaking or cracking.

The torsion portions 15 and 16 near the open ends of the flat tubes 5 and 6 have a torsion width (dimension of the torsion portion along the longitudinal direction of the flat tube) L (shown in FIG. 3), It is preferable to set it within the range of 1.0 times or more and 1.3 times or less (1. OW≤L≤l. 3W) with respect to the tube width W. If L is less than 1.OW, the elongation of the material will increase, and the bent portion will be easily broken or cracked, increasing the risk of fluid leakage inside the tube (see Fig. 13). For this reason, it is necessary to make the tube width W 1.0 times or more to eliminate the risk of leakage. Also screw If the width is too large, the area where the fins cannot be attached becomes large, so that the useless area that does not contribute to heat exchange becomes large. For this reason, taking into account the permissible limit of the decrease in heat exchange capacity, setting the above range can eliminate the risk of leakage and suppress the influence of the heat exchange capacity to an allowable range.

Claims

The scope of the claims

[1] A tube insert formed into a flat tubular shape having both ends opened and having a fluid passage therein, with the vicinity of the open end twisted and the open end extended along the center line of the header pipe. In the flat tube for heat exchange inserted into the hole,

An opening end of the flat tube is offset from a center line in a longitudinal direction of the flat tube, and the offset amount is set so as to make the opening end coincide with a side edge of the flat tube. Heat exchange flat tube.

[2] A tube insertion formed into a flat tube having both ends opened and having a fluid passage therein, a portion near the opening end being twisted, and the opening end extending along the center line of the header pipe. In the flat tube for heat exchange inserted into the hole,

The open end of the flat tube is offset from the center line in the longitudinal direction of the flat tube, and the dimension of the torsion portion along the longitudinal direction of the flat tube is 1.0 times the width of the flat tube. A flat tube for a heat exchanger, characterized in that it is set within the range of 1.3 times or less.

[3] a header pipe, a flat tube having both ends opened and formed into a flat tube having a fluid passage therein, and an open end inserted into a tube insertion hole formed in the header pipe; In a heat exchanger having fins interposed between tubes,

The tube insertion hole is formed as an elongated hole extending along the center line of the header pipe, and the vicinity of the open end of the flat tube is twisted in accordance with this, and the open end is centered in the longitudinal direction of the flat tube. The heat exchange is provided so as to be offset with respect to a line, and the amount of offset is set to an amount such that an end of the opening coincides with a side edge of the flat tube.

[4] The header noise is provided on the first header pipe, a relay header pipe provided opposite thereto, and provided adjacent to the first header pipe, and provided facing the relay header pipe. And a second header pipe,

The flat tube includes a plurality of first flat tubes provided so as to communicate the first header pipe and the relay header nove, the relay header pipe, and the first flat tube. A plurality of second flat tubes provided so as to communicate with the second header pipe,

The first flat tube is provided with an opening end inserted into a tube insertion hole of the first header pipe offset to a side edge of the second flat tube force that moves away from the second flat tube. An opening end inserted into the tube insertion hole is provided offset to a side edge close to the second flat tube;

The second flat tube is provided with an opening end inserted into a tube insertion hole of the second header pipe offset from a side edge of the first flat tube force that moves away from the first flat tube, and the relay header pipe is provided. 4. The heat exchange according to claim 3, wherein an open end inserted into the tube insertion hole is offset from a side edge close to the first flat tube.

[5] A tube insertion hole formed in a flat tubular shape having both ends opened and having a fluid passage therein, and a portion near the open end twisted so that the open end extends along the center line of the header pipe. The heat exchange flat tube is inserted into the flat tube and is provided offset from the longitudinal center line of the flat tube.

The opening end of the flat tube and a part separated by a predetermined distance from the opening end are sandwiched by a chuck member, and the chuck member sandwiching the opening end is rotated around an axis in the same direction as the longitudinal direction of the flat tube. A method for forming a flat tube for a heat exchanger, characterized in that the flat tube is slid in an offset direction while being moved.

[6] A tube insertion hole formed in a flat tubular shape having both ends opened and having a fluid passage therein, and a portion near the open end twisted to extend the open end along the center line of the header pipe. The heat exchange flat tube is inserted into the flat tube and is provided offset from the longitudinal center line of the flat tube.

The opening end of the flat tube and a portion separated by a predetermined distance from the opening end are sandwiched by a chuck member, and the chuck member sandwiching the opening end is slid in the direction of sandwiching. A method for forming a flat tube for a heat exchanger, characterized in that the tube is rotated around a center line in a direction.

[7] formed in a flat tubular shape with both ends opened and having a fluid passage inside, near the open end Is twisted so that the open end is inserted into the tube insertion hole extending along the center line of the header pipe, and is provided offset from the longitudinal center line of the flat tube. For the method of molding a replacement flat tube,

A portion separated by a predetermined distance from the open end of the flat tube is sandwiched by a chuck member, and then the open end is displaced in a direction to be sandwiched by another chuck member. Wherein the chuck member sandwiching the flat tube is rotated about the longitudinal center line of the flat tube as an axis.

[8] A tube insertion hole formed in a flat tubular shape having both ends opened and having a fluid passage therein, and a portion near the open end twisted to extend the open end along the center line of the header pipe. The heat exchange flat tube is inserted into the flat tube and is provided offset from the longitudinal center line of the flat tube.

The opening end of the flat tube and a part separated by a predetermined distance from the opening end are sandwiched by a chuck member, and the chuck member sandwiching the opening end is rotated around an axis in the same direction as the longitudinal direction of the flat tube. And then sliding in the offset direction.

[9] The chuck member sandwiching the open end of the flat tube, when being rotated around an axis in the same direction as the longitudinal direction of the flat tube, the chuck member sandwiching a portion separated by a predetermined distance from the open end. The method for forming a flat tube for a heat exchanger according to any one of claims 5 to 8, wherein the method is arranged to be close to a member.

[10] The chuck member provided at a position separated by a predetermined distance from an open end of the flat tube has a predetermined clearance provided between the chuck member and the flat tube. — The method for forming a flat tube for a heat exchanger according to any one of the above items 9.

[11] The apparatus according to any one of claims 5 to 9, wherein a portion separated by a predetermined distance from the open end portion of the flat tube is sandwiched by a pair of rollers instead of the chuck member. A method for forming the flat tube for a heat exchanger according to the above.

[12] The chuck member that sandwiches the open end portion of the flat tube and the chuck member that is provided at a portion separated by a predetermined distance from the chuck member are located at the corners of the sandwiching portions on the sides facing each other. The method for forming a flat tube for a heat exchanger according to any one of claims 5 to 9, wherein an R-shaped chamfer is provided.

13. The method for forming a flat tube for heat exchange according to claim 12, wherein the chamfer radius R is set so that R≥0.5t with respect to a plate thickness t of the flat tube. .