JPH1034244A - Method for roll forming of metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bend the metal plate without causing deformation such as wrinkle, strain or cracks in the roll forming method of the metal plate, in which obtuse angle shaped bent parts are formed on both sides of a circular arc part by supplying continuously the metal plates between first roll and second roll. SOLUTION: In the method for the roll forming of the metal plate, the metal plate 39 is deformed in a circular arc shape by supplying continuously the metal plate 39 between the first roll 31 and the second roll 33, and also obtuse angle shaped bent parts 43 are formed on both sides of this circular arc part 41, and by the first roll 31 and the second roll 33, a plastic deformation is performed by pressing the bending point 45 of the bending part 43 of the metal plate 39 only on the same vertical lines 55 perpendicular to the rotary center axes 35, 37 of the first roll 31 and the second roll 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to roll forming of a plate material in which a plate material is continuously supplied between a first roll and a second roll to form obtuse bent portions on both sides of an arc portion. About the method.

[0002]

2. Description of the Related Art Conventionally, as tubes for heat exchangers used in heat exchangers of radiators, condensers, etc. of automobiles,
For example, one disclosed in JP-A-63-242432 is known. FIG. 4 shows a heat exchanger tube disclosed in this publication. The heat exchanger tube 11 is formed by rolling both ends of an aluminum plate 13 having a brazing material clad on the surface thereof in the same direction by roll forming. The bent portion 13a is formed in the shape of a circle. Next, the bent portion 13a is made to protrude in an abutting state, and then the bent portions 13a are brazed to each other.

[0003] In this heat exchanger tube, the bending point 13b of the bending portion 13a is formed at a right angle.
As shown in FIG. 5, when fitted into the tube hole 15a of the seat plate 15, no space is formed between the tube hole 15a and the tube 11 for the heat exchanger.
a can be surely brazed. That is, as shown by a two-dot chain line in FIG.
Is formed in an arc shape, a space 17 is formed between the tube hole 15a and the heat exchanger tube 11, and it becomes difficult to securely braze the heat exchanger tube 11 to the tube hole 15a.

FIG. 6 shows a roll forming method of the above-mentioned bent portion 13a. In this forming method, first, as shown in FIG. The plate 13 is continuously supplied to the gap 21 and the plate 13 is deformed into an arc shape, and at the same time, obtuse bent portions 25 are formed on both sides of the arc portion 23.

[0005] Next, as shown in FIG.
Between the first roll 19A and the second roll 21A.
Is continuously supplied, the curvature of the arc portion 23a of the plate 13 is increased, and at the same time, the bending angles of the bent portions 25a on both sides of the arc portion 23a are reduced. And finally, the first of the third stage
The plate material 13 is continuously supplied between the roll 27 and the second roll 29, and the arc portion 23a of the plate material 13 is made into a flat plane portion 23b, and at the same time, the bent portions 25a on both sides of the arc portion 23a are formed. It is bent at a right angle to form a right-angle bent portion 25b.

[0006]

However, in such a conventional roll forming method, as shown in FIG. 7, the distance W between the first roll 19 and the second roll 21 is reduced by the sheet material 1.
Since the thickness is smaller than the thickness of No. 3, there is a problem that deformation such as wrinkles and distortions or cracks occur in the entire plate material 13.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a method for forming a roll of a sheet material that can bend the sheet material without generating deformation or cracks such as wrinkles and distortions. I do.

[0008]

According to a first aspect of the present invention, there is provided a roll forming method for a plate material, wherein the plate material is continuously supplied between a first roll and a second roll to deform the plate material into an arc shape. In the method of forming a plate material having obtuse bent portions formed on both sides of the arc portion, the bending point of the bent portion of the plate material is set by the first roll and the second roll. The first roll and the second roll are plastically deformed by pressing only on the same vertical line perpendicular to the rotation center axis.

According to a second aspect of the present invention, in the roll forming method for a plate material according to the first aspect, the first roll projects toward the second roll at a position corresponding to the bending point. A convex portion is formed on the second roll, and a concave portion is formed on the second roll at a position corresponding to the convex portion, and a vertex of the convex portion and a vertex of the concave portion correspond to the first roll and the second roll. Are positioned on the same vertical line perpendicular to the rotation center axis.

According to a third aspect of the present invention, there is provided a plate material roll forming method according to the first or second aspect, wherein the first roll and the second roll are arranged in a plurality of stages.
The angle of the bent portion is sequentially reduced. A method of forming a sheet material according to claim 4, wherein in the method of forming a sheet material according to any one of claims 1 to 3, the bent portion of the plate material is bent at a predetermined angle, and then the bent portion is formed. Is bent at right angles by roll forming.

According to a fifth aspect of the present invention, there is provided a roll forming method for a sheet material according to any one of the first to fourth aspects, wherein the plate material is formed of an aluminum clad material on which a brazing material layer is formed. It is a plate material for a heat exchanger tube.

According to the first aspect of the present invention, the bending point of the plate is pressed only on the same vertical line perpendicular to the rotation center axis of the first roll and the second roll. The bending point is plastically deformed to form a bent portion.

According to a second aspect of the present invention, the apex of the convex portion formed on the first roll and the apex of the concave portion formed on the second roll are positioned on the same vertical line. The bending point of the plate is pressed by the vertex and its vicinity and the vertex of the concave portion and its vicinity. According to the third aspect of the present invention, the angle of the bent portion is sequentially reduced by the first roll and the second roll disposed over a plurality of stages.

In the method for rolling a plate material according to the fourth aspect, after bending the bent portion of the plate material at a predetermined angle, the bent portion is bent at a right angle by roll forming. In the roll forming method for a plate material according to claim 5, the plate material is a plate material for a heat exchanger tube made of an aluminum clad material on which a brazing material layer is formed. Then, bending both ends of the plate material in the same direction by roll forming to form a bent portion, and then projecting the bent portion inward while abutting the bent portion, then brazing the bent portions to each other. Produces a heat exchanger tube.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a method for roll-forming a plate material according to the present invention.
Reference numerals 1 and 33 indicate a first roll and a second roll. First roll 31 and second roll 33
Are arranged so that the rotation center axes 35 and 37 are parallel to each other.

Between the first roll 31 and the second roll 33, a plate 39 for a heat exchanger tube made of an aluminum clad material having a brazing material layer formed on its surface is located. The plate 39 is formed by the first roll 31 and the second roll 31.
And the first roll 31 and the second roll 33 form an arc portion 41.
At the same time, obtuse bent portions 43 are formed on both sides of the arc portion 41.

The first roll 31 has a projection 47 projecting toward the second roll 33 at a position corresponding to the bending point 45 of the bending section 43. Between them, a first arc surface 49 is formed in a concave shape. Also,
The second roll 33 has concave portions 5 at positions corresponding to the convex portions 47.
1 are formed, and between these concave portions 51, a second circular arc surface 53 is formed in a convex shape.

Then, the vertex P1 of the convex portion 47 and the vertex P2 of the concave portion 51 correspond to the first roll 31 and the second roll 3 respectively.
3 are located on the same vertical line 55 perpendicular to the rotation center axes 35 and 37. Further, the curvature of the first circular surface 49 formed on the first roll 31 is made larger than the curvature of the second circular surface 53 formed on the second roll 33, and the plate material 39 is formed.
An escape space S1 is formed between the first roll 31 and the first roll 31.

Further, the interval between the bent portion forming surface 57 of the convex portion 47 of the first roll 31 and the bent portion forming surface 59 of the concave portion 51 of the second roll 33 is increased outward, and the plate material 39 is formed.
A relief space S2 is formed between the first roll 31 and the first roll 31. In the above-described plate material roll forming method, the bending point 45 of the plate material 39 is determined by the first roll 31 and the second roll 3.
3 is pressed only on the same vertical line 55 perpendicular to the rotation center axes 35 and 37, whereby the bending point 45 is plastically deformed and the bent portion 43 is formed.

In this embodiment, the thickness of the plate member 39 is, for example, 0.2 to 0.5 mm, and the thickness at the bending point 45 is reduced by about 10% due to plastic deformation due to pressing. Further, in the above-described plate material roll forming method, the plate material 39 is naturally deformed in the unconstrained state along the second arc surface 53 and the bent portion forming surface 59 of the second roll 33 and the arc material 41 is formed on the plate material 39. And a bent portion 43 is formed.

In the above-described method of forming a plate material, the bending point 45 of the plate material 39 is set on the same vertical line 55 perpendicular to the rotation center axes 35 and 37 of the first roll 31 and the second roll 33. Since the bending point 45 is plastically deformed by pressing only, the plate member 39 can be bent without making the bending point 45 into an arc shape. The plate 39
Is not pressed by the first roll 31 and the second roll 33 except at the bending point 45, and is in an unconstrained state at a position other than the bending point 45, thereby reliably preventing the plate 39 from being deformed such as wrinkles. can do.

Further, in the above-described method of forming a roll of a plate material, the apex P1 of the convex portion 47 formed on the first roll 31
And the vertex P2 of the concave portion 51 formed in the second roll 33 is located on the same vertical line 55 perpendicular to the rotation center axes 35 and 37 of the first roll 31 and the second roll 33. The plate 39 can be easily and reliably bent without forming the curved point 45 in an arc shape.

FIG. 2 shows a heat exchanger tube manufactured by using the above-described sheet material roll forming method. This heat exchanger tube is made of an aluminum plate material 39 whose surface is clad with a brazing material layer. Are bent in the same direction at right angles by the above-described roll forming method to form a right-angled bent portion 61. Next, the right-angled bent portion 61 is projected inward in an abutting state, and then the right-angled bent portion is formed. The parts 61 are formed by brazing each other.

FIG. 3 shows a process of bending both ends of the above-mentioned plate material 39 at right angles in the same direction to form a right-angle bent portion 61. In this process, first, the first step is to dispose two stages. Roll 31, 31A and second roll 3
3, 33A, the angles of the bent portions 43, 43A are sequentially reduced. In this embodiment, the first roll 3
1, 31A and the second rolls 33, 33A are arranged in two stages, and the angles of the bent portions 43, 43A are sequentially reduced. However, the first roll and the second roll are arranged in three or more stages, and the folding is performed. The angle of the curved portion may be sequentially reduced.

In FIG. 3B, compared to FIG.
Convex portion 47A of second roll 31A and second roll 33A
The angle of the concave portion 51A is reduced. (B)
In comparison with (a), the first roll 31A and the second
The curvature of the first arc surface 49A and the second arc surface 53A of the roll 33A is increased.

In this step, after the bent portion 43A of the plate 39 is bent at a predetermined angle as shown in (b), the bent portion 43A is moved to the first roll as shown in (c). 6
It is bent at a right angle by the third and second rolls 65 to form a right-angle bent portion 61.

In this embodiment, a pressing surface 63a is formed at the end of the first roll 63, and by pressing the end surface of the bent portion 43A with the pressing surface 63a, the bending point of the right-angle bent portion 61 is formed. The arc portion of 67 can be reduced more reliably. When the end surface of the bent portion 43A is pressed by the pressing surface 63a in this manner, deformation such as wrinkles may occur due to variation in the thickness of the plate material 39. If deformation such as wrinkles occurs, the pressing surface 63a It is desirable that the end face of the bent portion 43A be in an unconstrained state without providing the end portion.

In the above-described embodiment, an example in which the present invention is applied to the bending of the aluminum plate 39 has been described. However, the present invention is not limited to such an embodiment. And the like can be applied to the bending of plate materials. In the above-described embodiment, an example in which the present invention is applied to the manufacture of a tube for a heat exchanger has been described. However, the present invention is not limited to such an embodiment, and is widely applied to bending of both ends of a plate material. can do.

[0029]

As described above, in the method for forming a plate material according to the first aspect, since the plate material is not pressed by the first roll and the second roll except at the bending point, the plate material is not restrained except at the bending point. In this state, it is possible to reliably prevent the plate material from being deformed such as wrinkles and distortions or cracks.

Further, since the bending point of the plate is pressed only on the same vertical line perpendicular to the rotation center axis of the first roll and the second roll, the bending point is plastically deformed. The plate can be bent without making the points arc-shaped. In the roll forming method for a plate material according to claim 2, the first
Since the apex of the convex portion formed on the second roll and the apex of the concave portion formed on the second roll are located on the same vertical line perpendicular to the rotation center axes of the first roll and the second roll,
The plate can be easily and reliably bent without making the bending points arc-shaped.

According to the third aspect of the present invention, the angle of the bent portion is sequentially reduced by the first roll and the second roll which are arranged in a plurality of stages, so that the bending point is impossible. The plate can be bent at a predetermined angle without applying a stress. According to the roll forming method of the plate material of the fourth aspect, the bent portion of the plate material is bent at a predetermined angle, and then the bent portion is bent at a right angle by roll forming. An unfolded portion can be reliably obtained.

According to the plate material roll forming method of the fifth aspect, the tube for the heat exchanger can be manufactured easily and reliably.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for roll-forming a plate material of the present invention.

FIG. 2 is a front view showing a heat exchanger tube in which a bent portion is formed by using the plate material roll forming method of FIG. 1;

FIG. 3 is an explanatory view showing a roll forming step of a bent portion of the heat exchanger tube of FIG. 2;

FIG. 4 is a front view showing a conventional heat exchanger tube.

FIG. 5 is an explanatory view showing a state in which the heat exchanger tube of FIG. 4 is inserted into a tube hole of a seat plate.

FIG. 6 is an explanatory view showing a roll forming step of a bent portion of the heat exchanger tube of FIG.

FIG. 7 is an explanatory view showing an enlarged bending process of FIG. 6;

[Description of Signs] 31 First roll 33 Second roll 35, 37 Rotation center axis 39 Plate 41 Arc section 43 Bend section 45 Bend point 47 Convex section 51 Concave section P1, P2 Vertex

Claims (5)

[Claims] 1. A plate material (39) is continuously supplied between a first roll (31) and a second roll (33) to deform the plate material (39) into an arc shape, and to change the arc shape. In a roll forming method for a plate material in which obtuse bent portions (43) are formed on both sides of a portion (41), the plate material (39) is formed by the first roll (31) and the second roll (33). The bending point (45) of the bending portion (43) is defined by the same vertical line (55) perpendicular to the rotation center axes (35, 37) of the first roll (31) and the second roll (33). A roll forming method for a sheet material, characterized in that it is pressed only above and plastically deformed. 2. The method according to claim 1, wherein the first roll (31) projects toward the second roll (33) at a position corresponding to the bending point (45). A convex portion (47) is formed, and a concave portion (51) is formed on the second roll (33) at a position corresponding to the convex portion (47), and a vertex (P1) of the convex portion (47) is formed. And the recess (5
The vertex (P2) of 1) corresponds to the rotation center axes (35, 37) of the first roll (31) and the second roll (33).
A sheet material roll forming method, wherein the sheet material is positioned on the same vertical line (55) perpendicular to the sheet. 3. The method according to claim 1, wherein the first roll (31) and the second roll (33).
Are arranged in a plurality of stages, and the angle of the bent portion (43) is gradually reduced. 4. The method according to claim 1, wherein the bent portion (43) of the plate material (39) is bent at a predetermined angle, and then the bent portion is formed. (43) A method for forming a sheet material into a roll, wherein the sheet is bent at a right angle by roll forming. 5. The heat exchanger tube plate according to claim 1, wherein the plate (39) is made of an aluminum clad material on which a brazing material layer is formed. A roll forming method for a plate material, characterized in that: