JP2009162447A - Multi-hole flat tube and single hole tube material for multi-hole flat tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat tube with favorable pressure resistance and easy thinning. <P>SOLUTION: The flat tube 1 of a multi-hole structure is formed by connecting the single hole tube materials 10, 10 by fitting together a recessed part 11 for connection formed by invaginating one part of a side face of the single hole tube material 10 throughout a whole tube material length, and a protruding part 12 for connection formed by protruding one part of a side face of the adjacent single hole tube material 10 throughout a whole tube material length. The single hole tube material is composed by bending one plate material so as to secure an internal space and carrying out mutual face-to-face contact of both tip sides. The flat tube with the multi-hole structure with high pressure resistance can be obtained by using a thin plate, and an internal volume with sufficient size appropriating a material amount can be obtained. Contact of a sacrificial material side and a flux can be avoided, and Mg can be contained in a sacrificial material to improve strength without causing a brazing defect. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multi-hole flat tube suitable for an automobile heat exchanger manufactured by a brazing method such as a radiator and a condenser, and a single-hole tube material for a multi-hole flat tube used for manufacturing the multi-hole flat tube.

  Conventionally, a tube material of a heat exchanger for an automobile has a pipe-like composite material in which JIS3003 alloy or the like is used as a core, JIS7072 alloy or the like is sacrificed on one side, and JIS4045 alloy or the like is clad on the other side. An electric resistance sewing tube was used in which the butt portion was joined by high frequency heating. Moreover, as shown to Fig.5 (a), the extrusion multi-hole pipe 20 manufactured by an extrusion process is proposed and is provided for practical use.

  By the way, in recent years, for the purpose of reducing the weight of the heat exchanger and reducing the cost, the members used, particularly the tube material, tend to be thinner. However, the limit of thinning of the ERW tube is about 0.20 mm due to the problem of formability. If the thickness is less than this, the difficulty of pipe making increases and the mass productivity decreases. Further, when the thickness is reduced to about 0.20 mm or less, the pressure resistance as the heat exchanger tube may be insufficient because it is a single tube. The extruded multi-hole tube can increase the pressure strength by the multi-hole structure, but it is difficult to reduce the thickness due to the extrusion technique.

  Moreover, as shown in FIG.5 (b), what inserted the inner fin 22 in the flat tube 21 is proposed as what obtains a multi-hole structure. However, the process of inserting the inner fins 22 into the tube is difficult to work and reduces productivity. In particular, in a tube having a small diameter and a small diameter, the reduction in productivity becomes remarkable.

  In such a situation, in order to reduce the thickness of the tube, as shown in FIG. 5 (c), the tube material 23 is bent into a B shape with the tube material sacrificial material inside, and both sides thereof are brazed. A tube 24 formed by joining has been proposed (see, for example, Patent Document 1) and is becoming mainstream nowadays.

Further, the plate member 25 is bent so that an internal space is obtained, and the tip side is joined, and a bead 26 protruding inward at a predetermined interval is formed on the plate surface, and the inner surface of the plate member 25 facing the tip portion of the bead 26 is formed. A tube 27 having a multi-hole structure by bringing it into contact with each other and a manufacturing method thereof have been proposed (see Patent Document 2).
JP-A-11-277166 JP 11-63872 A

  By the way, in reducing the thickness of the tube, it is necessary to increase the material strength to meet the thickness reduction. In the ERW tube, there is a method of adding Mg or Si to the sacrificial material on the inner surface side and using diffusion during brazing heat treatment to improve the strength of the core material and also improving the strength of the sacrificial material itself. Proposed. However, since the sacrificial material serves as a joining surface in the tube that is brazed in the B shape, when a sacrificial material containing Mg is used, the tube joining portion (inner column) tip and the sacrificial material (Mg-containing layer) are joined. In some parts, the flux reacts with Mg and the flux becomes inactive, which may cause brazing failure. For this reason, a high-strength Mg-added alloy cannot be used in the tube.

  Moreover, in the said tube which bends a board | plate material and makes it a multi-hole structure, the flow-path cross-sectional area formed with respect to the material amount to be used is small, and it is disadvantageous for material cost and weight reduction of a heat exchanger. In addition, the groove formed on the outer surface of the tube along with the formation of the bead becomes a brazing flow point of the header or the like in the brazing process of heat exchanger production, and causes brazing failure due to erosion of the tube or lack of header brazing. .

  The present invention has been made against the background of the above circumstances, and includes a multi-hole flat tube that is excellent in pressure resistance and can be reduced in thickness and weight, and a single-hole tube material for a multi-hole flat tube used for manufacturing the multi-hole flat tube. The purpose is to provide.

  That is, among the multi-hole flat tubes of the present invention, the first present invention includes a connecting concave portion formed by indenting part of one side surface of a single-hole tube material over the entire length of the tube material, and an adjacent single-hole tube material. A part of one side surface of the hole tube material protrudes over the entire length of the tube material and is fitted with a connecting convex portion so that the single hole tube materials are connected to each other to form a multi-hole structure. And

  In the multi-hole flat tube according to the second aspect of the present invention, in the first aspect of the present invention, the single-hole tube member is formed by folding a single plate member so as to secure an internal space, and both tip sides face each other. It is characterized by being comprised.

  In the multi-hole flat tube according to the third aspect of the present invention, in the second aspect of the present invention, the single-hole tube material is such that the plate material of the folded portion is indented inward to form the connection recess. It is characterized by.

  In the multi-hole flat tube according to the fourth aspect of the present invention, in the second or third aspect of the present invention, the single-hole tube material has the connecting convex portion formed by both end sides that are in contact with each other. It is characterized by that.

  A multi-hole flat tube according to a fifth aspect of the present invention is the multi-hole flat tube according to any one of the second to fourth aspects of the present invention, wherein the single-hole tube material is folded so that the leading end side of the plate material is overlapped inside, The connecting protrusions are formed in contact with each other.

  The multi-hole flat tube according to the sixth aspect of the present invention is the flat tube according to any one of the first to fifth aspects, wherein the single-hole tube material is a brazing material on the surface side, a sacrificial material on the inner surface side, and a core material on the inner layer. The clad material is laminated so as to be positioned.

  In the single-hole tube material for a multi-hole flat tube of the seventh aspect of the present invention, a part of one side surface of the single-hole tube material body is indented over the entire length of the tube material, A connecting concave portion into which a connecting convex portion formed over the entire length of the tube material is fitted is formed in part.

  In the single-hole tube material for a multi-hole flat tube according to the eighth aspect of the present invention, a part of one side surface of the single-hole tube material main body projects over the entire length of the tube material, and a part of one side surface of the other single-hole tube main body A connecting convex portion into which a connecting concave portion formed over the entire length of the tube material is fitted is formed.

  The single-hole tube material for a multi-hole flat tube according to the ninth aspect of the present invention is such that a part of one side surface of the single-hole tube material main body protrudes over the entire length of the tube material and a connecting concave portion of the adjacent single-hole tube material is fitted. A connecting convex portion is formed, a part of the other side surface is indented over the entire length of the tube material, and a connecting concave portion is formed in which the connecting convex portion of the adjacent single hole tube material is fitted. Features.

  That is, according to the multi-hole flat tube of the present invention, a part of one side surface of the single hole tube material is indented over the entire length of the tube material, and one side surface of the adjacent single hole tube material. A multi-hole structure with a high pressure resistance, because a single-hole tube material is connected to each other with a connecting convex part formed so that a part of the tube material protrudes over the entire length of the tube material and is connected to each other. The flat tube can be easily obtained, and the number of holes can be arbitrarily set. Moreover, there are few restrictions on manufacture and thickness reduction is easy.

  Further, according to the multi-hole flat tube according to another aspect of the present invention, the single-hole tube material is configured by folding a single plate material so as to secure an internal space and bringing both end sides into contact with each other. Therefore, a flat tube having a multi-hole structure with high pressure resistance can be obtained using a thin plate, and the internal volume can be sufficiently large to meet the material amount. In addition, since the contact between the sacrificial material side and the flux can be avoided, it is possible to increase the strength by adding Mg to the sacrificial material without causing brazing defects.

  Furthermore, according to the single hole tube material for a multi-hole flat tube of the present invention, the tube material over the entire length of the single hole tube material main body on a part of one side surface of the other single hole tube main body. The connecting concave portion into which the formed connecting convex portion is fitted is formed so as to be indented over the entire length of the tube material, and / or another single hole tube is formed on a part of one side surface of the single hole tube material main body. Since the connecting convex part to be fitted into the connecting concave part formed by indenting over the entire length of the tube material is formed over the entire length of the tube material on a part of one side surface of the main body, the single hole tube materials are By connecting, a multi-hole flat tube can be easily obtained. The connecting convex portion and the connecting concave portion are securely brazed by the brazing material on the surface of the single hole tube material.

(Embodiment 1)
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
A plurality of single-hole tube materials 10 ... 10 for a multi-hole flat tube shown in FIG. 1 have the same shape, the entire cross-section is a flat rectangular shape, the inside is a gap, and a part of one side surface of the tube material main body 10a. Are recessed along the longitudinal direction of the tube material to form a connecting recess 11 having a square cross section. Further, on a part of the other side surface of the tube main body 10a, a connecting convex portion 12 protruding outward is formed along the tube material longitudinal direction. The connecting convex portion 12 has a distal end portion that is further bent outward from the side surface of the plate member constituting the side surface of the single-hole tube material 10, and the distal end side of the bent piece is further folded inward to bend the remaining bending portion. The folded pieces 12a, 12a formed by being overlapped with the pieces are configured to face each other.

  The connecting concave portion 11 and the connecting convex portion 12 are respectively connected to the connecting convex portion 12 and the connecting concave portion 11 of the adjacent single hole tube materials 10. It is comprised so that it can connect mutually.

Next, the manufacturing process procedure of the single-hole tube material 10 will be described with reference to FIG.
For manufacturing the single-hole tube material 10, a clad plate material 100 in which a brazing material, a core material, and a sacrificial material (not shown) are laminated is used. In the figure, it is assumed that the sacrificial material is located on the upper layer side and the brazing material is located on the lower layer side.
The clad plate material 100 is sequentially formed by roll forming to obtain a single-hole tube material 10. First, the central portion of the clad material 100 is bulged upward in the figure (step a), and this is molded to form a concave portion 11 having a square cross section (step b). Next, both end portions of the clad plate 100 are bent upward in two steps (steps c to e), and the bent pieces on the end side are folded back and overlapped to form the folded piece 12a (step f). Next, both sides of the clad plate 100 are folded back to the upper side in the drawing with the both ends of the coupling recess 11 as the base so that the side faces are secured (steps g to h), and finally the folded pieces 12a and 12a Are brought into contact with each other to form the convex portion 12. Through the above process, the single-hole tube material 10 in which the connection concave portion 11 and the connection convex portion 12 are formed in the single-hole tube material main body 10a is obtained.

As a result of this step, in the single hole tube material 10, the brazing material is located on the surface side of the single hole tube material 10, and the sacrificial material is located on the inner surface side of the single hole tube material 10.
By connecting a plurality of single-hole tube members 10 by fitting the connecting concave portions 11 and the connecting convex portions 12, a flat tube 1 having a multi-hole structure is obtained as shown in FIG. This flat tube 1 can manufacture a heat exchanger by disposing fins (not shown) on the surface and assembling and brazing both end sides to headers (not shown). At this time, since the connecting concave portion 11 and the connecting convex portion 12 are in contact with each other, the brazing material forms the brazing and the adjacent single-hole tubes 10 and 10 are brazed. Securely join together. Moreover, in the connection convex part 12, since a contact surface becomes a brazing material in the contact between the folding pieces 12a and 12a, the brazing is similarly formed by the brazing, and the folding pieces 12a and 12a are reliably joined to each other. As a result, it is possible to reliably prevent leakage of the refrigerant at the joint and to obtain a tube having excellent pressure resistance.
Further, there is almost no contact between the sacrificial material and the flux, and there is no possibility of causing brazing failure even when the sacrificial material contains Mg.

  In the present invention, the folded pieces 12a and 12a may not be provided, but the front end side of the clad plate may be in contact with the sacrificial materials. In addition, although roll forming has been shown as a process for efficiently producing a single-hole tube material, the method for producing a single-hole tube material is not limited to this in the present invention. It is also possible to adopt this manufacturing method.

(Embodiment 2)
In the said embodiment, although the flat tube 1 was obtained by connecting the single hole tube material 10 of the same shape, the single hole arrange | positioned on both sides of a flat tube so that an uneven | corrugated shape may not arise in the both sides of the flat tube 1 The shape of the tube material may be different from the inner single-hole tube material.
FIG. 3 shows the flat tube 2 of this embodiment. As in the first embodiment, the single-hole tube material is a single-hole tube material 10 having a connecting convex portion 12 that fits into the connecting concave portion 11 of the single-hole tube material 10. 15 and a single-hole tube material 16 having a connection concave portion 11 fitted to the connection convex portion 12 of the single-hole tube material 10. The flat tube 2 is obtained by connecting these single hole tube materials 15, 10 and 16. These single-hole tube materials 15 and 16 can be manufactured by roll forming of a clad material or the like as in the first embodiment.

  The single hole tube material 15 forms the connecting convex portion 12 on the other side surface without forming the concave portion in the folded portion. Thereby, it can be set as the shape which does not have an unevenness | corrugation in the side surface different from the side surface in which the convex part 12 for a connection is formed. In addition, the single hole tube material 16 is formed such that the connecting concave portion 11 is formed in the folded portion, and the distal end side of the clad material is bent inward from the side surface of the single hole tube so that the bent portions face each other. Thereby, it can be set as the shape which does not have an unevenness | corrugation in the side surface side different from the side surface in which the connection recessed part 11 is formed. In addition, in FIG. 3, although the number of the single hole tube materials 10 is shown as one, the number can be made into arbitrary numbers of 2 or more as needed. Further, without using the single-hole tube material 10, the single-hole tube material 15 and the single-hole tube material 16 are connected by fitting the connection concave portion 11 and the connection convex portion 12 to obtain a flat tube. May be.

(Embodiment 3)
In each said embodiment, the flat tube of the square tube shape as a whole is obtained by making the whole shape of each single hole tube material into a square tube shape. However, the shape of the entire multi-hole flat tube can be changed by changing the shape of the single-hole tube material positioned on both sides of the multi-hole flat tube.

  FIG. 4 shows the flat tube 3 of this embodiment. As in the first embodiment, the single-hole tube material 10 is used as the inner single-hole tube material, and the connection convex portion 12 that fits into the connection concave portion 11 of the single-hole tube material 10 on one side end side is provided. By connecting these using the single hole tube material 17 which has and the single hole tube material 18 which has the connection recessed part 11 in which the connection convex part 12 of the single hole tube material 10 of the other side end side is fitted. A flat tube 3 is obtained. These single-hole tube materials 17 and 18 can be manufactured by roll forming of a clad material or the like as in the first embodiment.

The single hole tube material 17 is formed with a curved surface without forming a concave portion in the folded portion, and the connecting convex portion 12 is formed on the other side surface in the same manner as the single hole tube material 10. The single-hole tube material 18 is formed with a connecting concave portion 11 at the folded portion in the same manner as the single-hole tube material 10, and the other side surface is bent so that the front end side of the clad plate material is bent inward from the side surface. The tubes are in contact with each other.
By connecting the single-hole tube material 17, the single-hole tube material 10, and the single-hole tube material 18 to each other by fitting the connection concave portion 11 and the connection convex portion 12, both sides are curved as a whole. A flat tube 3 having the following is obtained.

Examples of the present invention will be described below.
The tube-forming material shown in Table 1 was prepared, and the multi-hole flat tube shown in Embodiment 1 and the B-type cross-sectional shape in the prior art (FIG. 5 (c)) under the conditions that the flow-path cross-sectional areas were almost equal to each other. ) Multi-hole flat tube.
In addition, about the tube of this invention, the dimension of the single hole tube material was changed, and the tube of the same flow-path cross-sectional area was produced and evaluated by 2 connection and 3 connection combination.

After combining the molded tube, fins, and header plate and applying Noclock flux of about 5 g / m ² , brazing heat treatment (600 ° C.) was performed in a high-purity nitrogen gas atmosphere to produce a heat exchanger (tube width) : 15.5 mm, number of tube stages: 36 stages, core size ... 330 mm length x 360 mm width).
Thereafter, a repeated pressurization test of 0.5 to 150 kPa was performed on the manufactured radiator, and the number of times until the tube was broken was measured. The results are shown in Table 2.

In the case of a tube having a B-shaped cross-section, if there is a bonding failure even at one place in the tube column, the number of times until breakage is remarkably reduced, so that the brazing property can be evaluated by this test.
As shown in Table 2, each of the above test materials can be manufactured with a plate thickness of 0.20 mm, and thinning is achieved. Furthermore, the tube of the present invention can be repeatedly pressurized a considerable number of times before breaking by a pressure test, and is excellent in pressure resistance. On the other hand, the B-shaped cross-section tube was ruptured relatively early and the pressure resistance was insufficient.

It is a figure which shows the single hole tube material and multi-hole flat tube in one Embodiment of this invention. Similarly, it is a flowchart which shows the manufacturing process of a single hole tube material. It is a figure which shows the single hole tube material and multi-hole flat tube in other embodiment of this invention. Similarly, it is a figure which shows the single hole tube material and multi-hole flat tube in other embodiment. It is a figure which shows the conventional multi-hole flat tube.

Explanation of symbols

1, 2, 3 Flat tube 10, 15, 16, 17, 18 Single hole tube material 11 Connection recess 12 Connection projection 12a Folding piece

Claims (9)

  A connecting recess formed by indenting part of one side of a single-hole tube material over the entire length of the tube material, and a part of one side surface of an adjacent single-hole tube material protruding over the entire length of the tube material. The multi-hole flat tube is characterized in that the single-hole tube members are connected to each other with a connecting convex portion to form a multi-hole structure.   The multi-hole flat tube according to claim 1, wherein the single-hole tube material is configured such that a single plate is folded back so as to secure an internal space, and both tip sides are brought into contact with each other. .   3. The multi-hole flat tube according to claim 2, wherein the single-hole tube material has the connecting concave portion formed by indenting the plate material of the folded portion inward. 4.   4. The multi-hole flat tube according to claim 2, wherein the single-hole tube material has the connecting convex portions formed by both end sides that are brought into contact with each other. 5.   The said single-hole tube material is folded back so that the front end side of a board | plate material may be piled up inside, and the folded-back part of both front-end | tips contacts each other, The said convex part for connection is formed, A multi-hole flat tube according to any one of the above.   The said single hole tube material consists of a clad material laminated | stacked so that a brazing | wax material on the surface side, a sacrificial material on the inner surface side, and a core material may be located in an inner layer, It is any one of Claims 1-5 characterized by the above-mentioned. Multi-hole flat tube.   A part of one side of the single-hole tube material body is indented over the entire length of the tube material, and a connecting convex portion formed over the entire length of the tube material is fitted to a part of one side surface of the other single-hole tube body. A single-hole tube material for a multi-hole flat tube, wherein a connecting concave portion is formed.   A part of one side surface of the single-hole tube material body protrudes over the entire length of the tube material, and a connection recess formed over the entire length of the tube material fits into a part of one side surface of the other single-hole tube body A single-hole tube material for a multi-hole flat tube, characterized in that a convex portion is formed.   A part of one side surface of the single-hole tube material main body protrudes over the entire length of the tube material, and a connection convex part is formed in which the connection concave part of the adjacent single-hole tube material fits, and part of the other side surface is the tube material A single hole tube material for a multi-hole flat tube, characterized in that a connection concave portion is formed in which the connection convex portion of the adjacent single hole tube material is fitted and fitted over the entire length.

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