JP3682633B2 - Method of forming tube element and heat exchanger using the tube element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger constituting a part of a cooling cycle used for a vehicle air conditioner or the like.
[0002]
[Prior art]
As a conventional heat exchanger, what is disclosed in Japanese Patent Laid-Open No. 7-190661 is constituted by a tube element formed by extrusion molding, a fin arranged between the tube elements, and a pair of headers. . This heat exchanger is used as an evaporator or as a heat exchanger in a dual type that can be switched between an evaporator and a condenser. When used as an evaporator, condensation that adheres to the surface of the tube element In order to efficiently discharge water, a concave drainage portion is formed on the surface of the tube element. Further, the drainage portion is not formed at the end of the tube element so that the tube element can be easily inserted into the header. In addition, it is desirable to form the tube element thin in order to improve the heat transfer performance of the tube element, but if the tube element is formed thin, the pressure resistance performance may be reduced. For this reason, a plurality of partition walls are formed in the tube element to improve the pressure resistance performance of the tube element.
[0003]
[Problems to be solved by the invention]
However, recently, for the purpose of improving productivity and reducing costs, it has been carried out to form a tube with a brazing sheet instead of extrusion molding. For this reason, a tube formed into a flat pipe shape with a brazing sheet has been used. In order to improve the pressure resistance performance, the inner fin has been inserted into the tube and brazed, but there has been a problem that the number of parts is increased and the number of work steps is increased.
[0004]
For this reason, an object of this invention is to provide the formation method of the tube element which forms a tube element with a brazing sheet | seat for the improvement of productivity, and cost reduction, and the heat exchanger using this tube element. .
[0005]
[Means for Solving the Problems]
Accordingly, the present invention is a tube element forming method comprising the following steps: (a) a bead forming step for forming beads that continuously protrude along the feeding direction of the brazing sheet; (b) the bead; A bead returning step for forming a flat portion by returning at a predetermined interval; (c) a position detection mark forming step for forming a position detection mark for recognizing a cutting position at the center between the bead ends returned; (d) From the bending step of gradually bending the brazing sheet into a flat pipe shape with the longitudinal center as a boundary, and (e) the cutting step of sequentially cutting the cutting positions between the bead ends recognized by the position detection marks. (Claim 1).
[0006]
Therefore, according to the present invention, the tube element can be continuously formed by roll forming with a brazing sheet, and the position of the cutting position in the cutting step is formed, so that the cutting position is clearly recognized. Therefore, the accuracy of the cutting position can be improved, and when the tube element is inserted into the header pipe, the end of the bead formed in the bead forming process and the end of the header pipe are close to each other. It is possible to prevent a brazing failure caused by the brazing between the element and the header pipe flowing into the bead.
[0007]
Further, according to the present invention, since the bead returning step and the position detection mark forming step are simultaneously formed (Claim 2), both steps can be completed in one step. Can be improved.
[0008]
Further, in the present invention, the position detection mark may be a hole formed in the vicinity of the center line (Claim 3), and the position detection mark is formed as a notch formed at at least one end of the center line. (Claim 4). As a result, the position detection mark can be easily formed.
[0009]
Furthermore, the position detection mark may be formed by leaving a part of the bead in a bead returning step for forming the flat portion (Claim 5). A reinforcement bead formed in the flat portion may be used (claim 6).
[0010]
As a result, the front position detection mark is formed by leaving a bead in the flat portion or a newly formed reinforcement bead, so that the position detection mark can be used as it is as a reinforcement of the flat portion. The strength of the flat portion can be improved, the deformation of the flat portion during roll forming can be prevented, and the pressure resistance of the flat portion can be improved after insertion into the header pipe.
[0011]
Furthermore, the present invention is to form a heat exchanger by stacking the tube elements formed by the above-described forming method together with a fin between a pair of header pipes in which a refrigerant inlet and outlet are formed ( Claim 7).
[0012]
As a result, tube elements can be formed more easily and cheaply than brazing sheets, and heat exchangers can be formed with tube elements with improved header pipe insertion and pressure resistance. Can be provided.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
A heat exchanger 1 shown in FIG. 1 is used, for example, as a condenser that constitutes a part of a cooling cycle of a vehicle air conditioner. Between the pair of header pipes 2 and 3 and the pair of header pipes 2 and 3 Are constituted by a plurality of tube elements 4 communicating with each other and corrugated fins 5 arranged between the tube elements 4. The pair of header pipes 2 and 3 are provided with a refrigerant inlet pipe 6 and a refrigerant outlet pipe 7.
[0015]
In this embodiment, a refrigerant inlet pipe 6 is provided at the upper part of one header pipe 2, a refrigerant outlet pipe 7 is provided at the lower part of the other header pipe 3, and predetermined portions of the header pipes 2 and 3 are provided. The heat exchanger 1 is divided by a partition plate (not shown) and has a plurality of stages (odd stages) of refrigerant flow paths. In FIG. 1, reference numeral 30 denotes a lid for closing the end portions of the header pipes 2 and 3, and 31 and 32 are end plates for holding both ends of the tube elements 4 and the fins 5 in the stacking direction. It is.
[0016]
In the heat exchanger 1 configured as described above, the tube element 4 is formed in a flat pipe shape by a brazing sheet, as shown in FIG. Beads 10 and 11 extending in the longitudinal direction of the tube element 4 are formed. The bead 10 is formed so as to protrude from the side surface 8 toward the side surface 9, and the tip of the bead 10 is brazed so as to contact the inside of the side surface 9. The bead 11 is formed so as to protrude from the side surface 9 toward the side surface 8. The tip is abutted against the inside of the side surface 8 and brazed. In this embodiment, the bead 10 and the bead 11 are arranged at positions shifted by a predetermined interval.
[0017]
Thereby, the space in the tube element 4 is divided by the beads 10 and 11, and a plurality of refrigerant flow paths 13, in this embodiment, three refrigerant flow paths 13 are formed. In addition, 14 and 15 in FIG. 3 are brazing allowances which form the joining side part of the tube element 4.
[0018]
Further, by forming the beads 10 and 11, the end portions thereof are brazed and fixed to the opposite side surfaces to improve the pressure resistance performance of the tube element 4, and the side surfaces of the beads 10 and 11 allow the refrigerant flow. Since the contact area between the refrigerant flowing through the passage 13 and the tube element 4 can be increased, and the contact area between the surface of the tube element 4 and air can be increased, the heat exchange efficiency of the refrigerant can be improved. Can do.
[0019]
However, when the beads 10 and 11 are formed to the end of the tube element 4, the shape of the insertion hole of the tube element formed in the header pipes 2 and 3 becomes complicated. The flat portions 12 that do not form the beads 10 and 11 over a predetermined range are provided at both ends in the longitudinal direction. As a result, the insertion holes 20 formed in the header pipes 2 and 3 can have a simple shape, and both end portions of the tube element 4 can also have a flat pipe shape. The workability of inserting into the pipes 2 and 3 can be improved.
[0020]
Further, the interval A between the end portions of the header pipes 2 and 3 and the end portions of the beads 10 and 11 is determined so that the heat exchanger 1 has a refrigerant with an experimental pressure of 60 kg / cm ² G (the pressure of the normal flowing refrigerant is 15 to 20 Kg / cm ² G), and as a result of investigating the relationship between the distance A and the deformation amount in the stacking direction of the heat exchanger, the range where the deformation amount is 0 mm is that the distance A is 0 mm. The range was 5 mm. When the deformation amount B of the error range is set as 2 mm as the allowable range, the range of the interval A is up to 10 mm.
[0021]
If the distance A is too small, the ends of the beads 10 and 11 are too close to the brazed portion between the header pipes 2 and 3 and the tube element 4, so that the solder at the joining portion flows into the beads 10 and 11. Therefore, there is a concern that the joining portion may be insufficient in soldering, resulting in poor bonding. For this reason, it is desired that the interval A be 2 mm or more as a range for preventing the brazing flow. Accordingly, it is desirable that the distance A is in the range of 2 mm to 10 mm.
[0022]
As a method of forming the tube element 1 having the above configuration, for example, there is a method shown in FIG. In this tube element forming method, first, a brazing sheet 41 wound around the drum 40 is continuously fed out from the drum 40. In a first step (bead forming step) 100, a bead that continuously protrudes along the feeding direction of the brazing sheet 41 by the first roller unit 101, in this embodiment, the bead 10. , 11 are formed. In the first step 100, brazing allowances 14 and 15 are also formed at the same time.
[0023]
Next, in a second step (in this embodiment, a step of simultaneously performing a bead return step and a position detection mark forming step) 110, the bead is placed on the brazing sheet 41 by the second roller unit 111. 10 and 11 are beaten back at a predetermined interval to form a flat portion 12 and at the same time, a central portion (cut) between the ends of the beads 10 and 10 and 11 and 11 located on both sides of the flat portion 12. A position detection mark 51 for recognizing the line 50 is formed. As described above, the relative position between the position of the flat portion 12 and the position of the position detection mark 51 on the flat 12 can be easily achieved by simultaneously performing the two steps, the bead return step and the position detection mark forming step. Although it is possible to fix, the workability is good, but in the second step 110, the bead returning step and the position detection mark forming step may be separate steps. That is, the flat portion 12 may be formed first by the roller portion that performs the bead return step, and the position detection mark 51 may be formed by the roller portion that performs the position detection mark formation step.
[0024]
In the third step (bending step) 120, the brazing sheet 41 is gradually bent into a flat tube shape by passing through the third roller portion 121 and the fourth roller portion 122, and The plurality of beads 10, 11 abut against the opposing surfaces so as to divide the space in the tube element into a plurality. Finally, in the fourth step (cutting step) 130, the brazing sheet 41 is sequentially cut along the cutting line 50 of the flat portion 12 recognized by the position detection mark 51, as shown in FIG. A tube element assembly 42 is formed.
[0025]
The tube element assembly 42 is inserted into and attached to the pair of header pipes 2 and 3, and is alternately laminated with the fins 5 between the pair of header pipes 2 and 3, and the jigs together with the end plates 31 and 32. The heat exchanger assembly sandwiched in the above can be constructed, and the heat exchanger can be formed by brazing the heat exchanger assembly in a furnace.
[0026]
As a result, in the tube element 4, the brazing allowances 14 and 15 are bonded together, and a plurality of brazing portions are provided between the tip portions of the beads 10 and 11 and the surface with which the tip portions abut. At the same time that the formation of the tube element 4 is completed by forming the refrigerant flow path 13, the flat portion 12 of the tube element 4 comes into contact with the insertion hole 20 of the tube element formed in the header pipes 2 and 3, and this portion is The header pipes 2 and 3 and the tube element 4 are fixed by brazing. At this time, since the center portion of the flat portion 12 is accurately cut by the position detection mark 41, a desired distance A between the header pipes 2, 3 and the end portions of the beads 10, 11 is set. Since the distance (2 mm to 10 mm) can be maintained, poor brazing of the brazed portion between the header pipes 2 and 3 and the tube element 4 can be avoided.
[0027]
In the first embodiment, as a position detection mark for recognizing the central portion 50 of the flat portion 12, a position detection hole 51 is provided in the vicinity of the central portion 50, particularly in the vicinity of the front in the feeding direction of the brazing sheet. The center line 50, in other words, the cutting line is recognized. The position and number of the holes 51 are not particularly limited.
[0028]
In the second embodiment shown in FIG. 5, as the position detection mark, a notch portion 52 is formed at a position that becomes both ends of the center line 50 in the brazing margins 14 and 15 formed on both sides of the brazing sheet 41, This notch 52 is recognized and cut. In the second embodiment, since the tube element is formed by bending the brazing sheet 41, the notch 52 is aligned with one side surface of the tube element and does not appear on both sides of the tube element. .
[0029]
In the third embodiment shown in FIGS. 6A and 6B, as a position detection mark, a portion of the bead returning process of the second process 110 in the bead returning process (unfilled bead) in the center line 50 is used. Is left as a position detection mark, and the approximate center of the unfilled beads 53 and 54 is cut. By forming the unfilled beads (position detection marks) 53 and 54, the unfilled beads 53 and 54 become reinforcing beads, so that deformation of the flat portion 12 can be prevented in a bending process of the brazing sheet. In addition, the pressure resistance performance of the flat portion 12 can be improved after being attached to the heat exchanger.
[0030]
Similarly, in the fourth embodiment shown in FIGS. 7A and 7B, a bead (reinforcement bead) 56 lower than the unplaced beads 53 and 54 sandwiches the center line 50 as a position detection mark. Formed on both sides. The reinforcing bead 56 is also a bead for reinforcing the flat portion 12 together with a role as a position detection mark. As a result, the same effects as the unfilled beads 53 and 54 are obtained.
[0031]
In the embodiment shown in FIG. 8 and FIG. 9, the forming plate for forming the tube element is formed by roll forming from the brazing sheet, and the formed forming plate is aligned and inserted into the header pipe. It is attached and brazed to form the tube element. In this method, it is necessary to align the forming plate accurately, and it is necessary to braze both sides of the tube element. However, since the step of bending the brazing sheet can be omitted, there is an advantage that the line length of the roll forming can be shortened, and the cost can be reduced as compared with the method described above.
[0032]
In the fifth embodiment shown in FIGS. 8A and 8B, a forming plate 61 for forming the tube element 60 is formed by roll forming with a brazing sheet, and the method includes the first step. The bead 64 and the brazing allowances 62 and 63 projecting continuously in accordance with the brazing sheet feeding method are formed, and the bead 64 is driven back at a predetermined interval in the second step to form the flat portion 65. In addition, a bead 66 is formed by leaving a bead of a predetermined range as it is as a position detection mark at the center portion of the flat portion 65, and the remaining bead 66 is used as a reinforcement bead. Then, in the third step, the molded plate 61 is formed by cutting according to the center line 68 recognized by the unfinished bead 66 as the position detection mark.
[0033]
The forming plate 61 is face-to-face aligned so that the beads 64 do not contact each other to form a tube element assembly. The tube element assembly is inserted into a header pipe and temporarily assembled as a heat exchanger assembly, and brazed. Thus, a heat exchanger is formed.
[0034]
Accordingly, the flat portion 65 can be prevented from being deformed in each process by the unfinished bead 66 formed on the molding plate, and the pressure resistance of the flat portion 65 positioned at both ends of the tube element 60 after the tube element 60 is formed. The performance can be improved.
[0035]
In the sixth embodiment shown in FIGS. 9A and 9B, a forming plate 61 for forming the tube element 60 is formed by roll forming with a brazing sheet, and the method includes the first step. The bead 64 and the brazing allowances 62 and 63 projecting continuously in accordance with the brazing sheet feeding method are formed, and the bead 64 is driven back at a predetermined interval in the second step to form the flat portion 65. At the same time, a reinforcing bead 67 is formed in the central portion of the flat portion 65, and this reinforcing bead 67 is used as a position detection mark. Then, in the third step, the molded plate 61 is formed by cutting along the center line 68 recognized by the reinforcing bead 67 as the position detection mark.
[0036]
The forming plate 61 is face-to-face aligned so that the beads 64 do not contact each other to form a tube element assembly. The tube element assembly is inserted into a header pipe and temporarily assembled as a heat exchanger assembly, and brazed. Thus, a heat exchanger is formed.
[0037]
Thereby, the deformation of the flat portion 65 in each step can be prevented by the reinforcing beads 67 formed on the molding plate, and the pressure resistance performance of the flat portions 65 located at both ends of the tube element 60 after the tube element 60 is formed. Can be improved.
[0038]
【The invention's effect】
As described above, according to the present invention, in the method of forming a tube element by roll forming with a brazing sheet, a position detection mark for recognizing the cutting location of the brazing sheet is formed on the brazing sheet, and the accuracy of the cutting position is determined. Since the dimension between the header pipe and the bead of the tube element can be strict, the brazability between the header pipe and the tube element can be improved. Thereby, the productivity of the tube element can be improved and the cost can be reduced.
[0039]
In addition, since the flat portion is reinforced by the position detection mark, deformation of the flat portion can be prevented and the pressure resistance performance of the tube element can be improved. Moreover, since a deformation | transformation can be prevented, the assembly property of a tube element and a header pipe can be improved.
[Brief description of the drawings]
FIG. 1 is a front view of a heat exchanger using a tube element formed in accordance with the present invention.
FIG. 2 is a partially enlarged perspective view showing an insertion state of a tube element and a header pipe of a heat exchanger according to the present invention.
FIG. 3 is an explanatory view showing a manufacturing process of the tube element according to the first embodiment of the present invention.
FIG. 4 is a partially enlarged perspective view of the tube element assembly according to the first embodiment.
FIG. 5 is an explanatory view showing a state of a brazing sheet according to a second embodiment.
FIG. 6A is an explanatory view showing a state of a brazing sheet according to the third embodiment, and FIG. 6B is a part of a tube element according to the third embodiment. It is an expansion perspective view.
FIG. 7 (a) is an explanatory view showing a state of a brazing sheet according to a fourth embodiment, and FIG. 7 (b) is a part of a tube element according to the fourth embodiment. It is an expansion perspective view.
FIG. 8 (a) is an explanatory view showing a state of a brazing sheet according to a fifth embodiment, and FIG. 8 (b) is a part of a tube element according to the fifth embodiment. It is an expansion perspective view.
FIG. 9 (a) is an explanatory view showing a state of a brazing sheet according to a sixth embodiment, and FIG. 9 (b) is a part of a tube element according to the sixth embodiment. It is an expansion perspective view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchanger 2, 3 Header pipe 4 Tube element 5 Fin 6 Refrigerant inlet pipe 7 Refrigerant outlet pipe 10, 11 Bead 12 Flat part 41 Brazing sheet 42 Tube element assembly 51 Undetected bead 56 Reinforcement bead 64 Bead 65 Flat portion 66 Unfilled bead 67 Reinforcement bead

Claims (7)

A method for forming a tube element comprising the following steps:
(A) a bead forming step of forming beads that continuously protrude along the feeding direction of the brazing sheet;
(B) A bead return step for forming the flat portion by returning the beads at a predetermined interval;
(C) a position detection mark forming step for forming a position detection mark for recognizing the center cutting position between the bead ends that have been repulsed;
(D) a step of bending the brazing sheet into a flat pipe by bending the central portion in the longitudinal direction, and (e) cutting for sequentially cutting the cutting positions between the bead ends recognized by the position detection marks. Process. 2. The tube element forming method according to claim 1, wherein the step of forming the flat portion and the step of forming the position detection mark for forming the position detection mark are performed in the same step. The tube element forming method according to claim 1, wherein the position detection mark is a hole formed in the vicinity of the center line. The tube element forming method according to claim 1, wherein the position detection mark is a cut formed at least at one end of the center line. 3. The tube element forming method according to claim 1, wherein the position detection mark is formed by leaving a part of the bead in a bead returning step for forming the flat portion. The tube element forming method according to claim 1, wherein the position detection mark is a reinforcing bead formed on the flat portion. A tube element formed by the forming method according to claim 1, 2, 3, 4, 5, or 6 is formed by laminating together with a fin between a pair of header pipes in which a refrigerant inlet and outlet are formed. Heat exchanger.

Images