JP3198892B2 - Coiled thin metal tube and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil-shaped thin metal tube obtained by winding a tube having a circular cross section in a coil shape, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 5 is a front view showing a schematic structure of a conventional tube winding device for producing a coil-shaped thin metal tube.
Hereinafter, a copper tube will be described as an example of the coiled thin metal tube. A winding drum 2 is arranged at a predetermined position to wind the copper tube 1 (coiled thin metal tube) housed in the container 6 in a rolled state in an aligned state, and the copper tube 1 and the winding drum 2 are arranged. Between them, a straightening roll 3 is provided. Further, a bending roll 4 is disposed near the winding drum 2, and a support roll 5 is disposed in front of the bending roll 4.

[0003] In the above configuration, the copper tube 1 drawn from the container 6 is passed through the straightening roll 3, passed through the support roll 5, and further wound under the bending roll 4 on the winding drum 2. The straightening roll 3 straightens the copper tube 1 by correcting the warp and twist of the copper tube 1. In addition, the straightening roll 3 may process a groove having a curvature on the roll surface in accordance with the diameter of the copper tube 1 to be wound. The bending roll 4 functions to perform preliminary bending in the bending direction at the time of winding to reduce the tension applied to the pipe after bending. Accordingly, even when the copper tube 1 is wound by the winding drum 2, the flattening of the copper tube 1 in the winding drum 2 due to sharp bending is reduced. Therefore, if the end of the copper tube 1 is fixed to the winding drum 2 and the winding drum 2 is rotated, the winding is performed while tension is applied to the copper tube 1.

There is also a method in which the bending roll 4 has a structure that can be moved up and down, and is bent in a manner similar to the winding diameter in accordance with the winding layer before winding. As described above, the bending roll 4 is provided to suppress the flattening of the copper tube generated at the time of winding the tube, and the cross-sectional shape of the copper tube in the state of being wound in a coil shape is close to a perfect circle, Can be made to fall within the standard range.

[0005]

However, in the above-described conventional structure, when the tube is wound on the winding drum and then unwound from the winding drum and straightened, the direction of bending of the tube is reversed. The tube is deformed according to the amount of bending in the direction, and the cross-sectional shape of the tube that was a perfect circle before unwinding becomes flat in the direction perpendicular to the coil axis. The amount of bending of a tube wound in a coil shape becomes larger toward the inside of the coil and becomes smaller toward the outside. For this reason, the flatness at the time of extending the bending of the tube is the largest inside the coil and becomes smaller toward the outside.
Even if the roundness of the tube in the coil state satisfies the standard, it will be out of the standard at the time of extension. Also, the roundness gradually changes from the beginning to the end of the pipe extension,
There is a problem that the quality is not stable. Furthermore, when a nonstandard tube tries to pass through a processing line, a defect such as buckling may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coil-shaped thin metal tube capable of guaranteeing roundness even when the wound tube is stretched, and a method for manufacturing the same.

[0007]

In order to achieve the above object, the present invention relates to a thin-walled metal tube having a circular cross section wound around a winding drum in a state of two or more layers of aligned coils. Is set so that the ratio D _V / D _H of the diameter D _V orthogonal to the diameter D _H parallel to the axis becomes smaller as going from the inner layer to the outer layer.

The object of the present invention is to provide a method for manufacturing a coiled thin metal tube in which a thin metal tube is wound around a winding drum in a state of two or more layers of aligned coils, the curvature according to the winding layer and the inner and outer diameters of the thin tube. The shape distortion at the time of winding up the thin-walled tube and the shape distortion at the time of being straightened after unwinding are determined based on It is also achieved by winding on a winding drum.

According to the above-mentioned means, the coil-shaped thin metal tube is usually wound up in multiple layers on a winding drum, and the winding diameter becomes larger as it becomes higher. Therefore, at the time of stretching, the flattening rate becomes larger inside the multilayer coil, and the cross-sectional shape becomes inconsistent. Therefore, in advance, the inside of the multilayer coil is molded so as to become a vertically long ellipse, and if it goes outside, it is molded so that it becomes closer to a circle from the ellipse and rolled up, after stretching, which layer is stretched It is also possible to obtain a metal tube that is close to a perfect circle.

Further, according to the other means described above, based on the change in the shape of the cross section of the tube accompanying the degree of flatness imparted at the time of winding by the bending roll and the winding drum, the tube to be wound on the winding drum is formed. The molding is performed from a direction orthogonal to the direction in which the flatness is given. If the forming amount is made equal to the flattening amount after the bending roll, the pipe cross section after stretching becomes a perfect circle.

At this time, it is sufficient that the forming amount (forming force) before the winding is applied before the winding position. However, the winding direction of the tube and the bending direction by the bending roll are performed in the vertical direction. The shaping before winding is performed from a horizontal direction perpendicular to the shape. Thereby, the pipe after the expansion can be made a perfect circle without being restricted by the installation place or the like.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a schematic configuration of an embodiment of a tube winding device suitable for winding a coiled thin metal tube according to the present invention. FIG. 2 is a plan view of the embodiment of FIG. In the following, a copper tube will be described as an example of the coiled thin metal tube.

The copper tube before winding is housed in a container 10 in a rolled state. A winding drum 12 for winding the copper tube 11 from the container 10 in an aligned state is provided at a predetermined position. This winding drum 12
It is composed of a cylindrical body 12a and disk-shaped flanges 12b provided on both end surfaces of the body 12a. A straightening roll 13 is provided between the copper tube 11 and the winding drum 12. A bending roll 14 is provided near the winding drum 12, and a support roll 15 (including an upper roll 15 a and a lower roll 15 b) is provided in the direction of the straightening roll 13 near the bending roll 4. Has been established.

Further, between the straightening roll 13 and the support roll 15, a forming roll 16 is provided. As shown in FIG. 2, the forming rolls 16 hold the copper tube 11 from both sides such that the bending rolls 14 come into contact with the vertical direction while the bending rolls 14 come into contact with the horizontal direction, which is a direction perpendicular to the bending direction. It is arranged in the form that it does. The shape of the forming surface of the rolls 16a and 16b may be a flat roll, an arc groove roll, a V groove roll, an elliptical groove roll, or the like. No driving force is applied to the rolls 16a and 16b from the outside (however, the driving force can be applied).
The copper tube 11 rotates due to friction caused by traveling. And
The forming roll 16 is provided with an adjusting handle 17 for adjusting the distance between the rolls 16a and 16b (that is, the pressing force).
It has. By rotating the adjustment handle 17, the rolls 16a and 16b approach or separate at the same rate according to the direction of rotation.

The winding drum 12 is provided with a winding number detector 18 for detecting the number of windings for each layer. The winding number detector 18 includes a main body 18a, a rod-shaped actuator 18b reciprocally inserted into the main body 18a,
And the roller 1 mounted on the tip of the actuator 18b
8c. The roller 18c is the winding drum 1
The actuator 18b moves in the direction of the main body each time the number of stages increases, and an electric signal corresponding to the amount of movement is transmitted to the main body 18 by the drum 18 or the surface of the already wound copper tube.
a.

Further, a control device 19 using a microcomputer is connected to the winding number detector 18. Furthermore,
The control device 19 is connected to a control motor 20 to be controlled, and serves as a roll movement drive source for changing the gap between the rolls 16a and 16b of the forming roll 16. In the configuration of FIG. 1, first, the copper tube 11 pulled out of the copper tube 11
Is passed through a support roll 15 through a straightening roll 13,
Further, the leading end is engaged with the winding drum 12 through the lower side of the bending roll 14. In the course of rotation of the winding drum 12, the straightening roll 13 corrects the copper tube 11 for warping, twisting, and the like to make the copper tube 11 a perfect circle. A groove having a radius of curvature may be formed on the roll surface in accordance with the diameter of the tube 11).

Further, a curvature is given to the copper tube 11 by the bending roll 14. At the time of winding by the winding drum 12, as shown in FIG.
Can be aligned and closely wound. For example, in the case of FIG. 2, winding is performed while moving the winding drum 12 in the upward direction in the figure, and when winding of one stage (for one layer) is completed, winding is performed while winding the second stage on the first stage. Taking drum 1
2 will be moved downward in the figure.

As described above, the roll width A of the forming roll 16
Is not linearly controlled in accordance with the number of windings because the amount of distortion applied to the copper tube 11 and the amount of molding due to the distortion do not change proportionally. When the amount of distortion to be applied is small, the amount of molding hardly changes due to the influence of springback, but the amount of molding becomes proportional to the amount of distortion to be applied.
The method for adjusting the roll width A varies depending on the outer diameter, wall thickness, hardness, winding drum diameter, and the like of the copper tube 11.

The copper tube 11 wound by the above-described control is deformed by the forming roll 16 to extend in the vertical direction (vertical direction), and is processed into an elliptical cross-section when it exits the forming roll 16. After this, the bending roll 14
During the bending process and the winding by the winding drum 12, the distortion (deformation) swells in the horizontal direction. The amount of pressing at this time is set in a direction perpendicular to the pressing roll 16.
If it is set equal to the pressing amount given by
1 will be wound in a perfect circle.

However, in the present invention, the winding drum 1
Since the copper tube 11 once wound into the tube 2 is stretched (unwound) and it is desired to obtain a perfect circle when it is straightened, a perfect circle at the time of winding will become flat when stretched. In view of this, the forming roll 16 is excessively flattened so that when a reverse deformation is applied at the time of stretching, the shape becomes a perfect circle.

The method for this will be described below. First,
The value of the interval A between the rolls 16a and 16b of the forming roll 16 is set to be equal to or larger than the diameter of the copper tube 11, and the copper tube 11 is wound around the winding drum 12 in the same state as in FIG. In this winding, a certain flat amount is given by the bending roll 14 and the winding drum 12. When the copper tube 11 is stretched from this state, the opposite deformation is applied, so that the flattening amount at the time of winding is reduced, and the copper tube 11 after being stretched becomes closer to a perfect circle. However, since the reverse deformation after stretching is smaller than the flattening amount at the time of winding, it does not return to a perfect circle.

Therefore, the shortage is formed beforehand by the forming roll 16 so that the copper tube 11 after being drawn from the winding drum 12 becomes a perfect circle. Assuming that the flattening amount of the bending roll 14 is F ₁ , the flattening amount of the winding drum 12 is F _2, and the deformation amount of the copper tube 11 after stretching is T, the forming amount P of the forming roll 16 is
P = F ₁ + F ₂ + T ± δ. Here, δ is a correction value for performing the correction because the coil diameter varies depending on the layer of the winding drum 12 at the time of extension. Flatness F
₁ and F ₂ are both in the same direction, and the deformation amount T is a direction inverted by 180 degrees. This setting is performed by the control device 19, and the correction of δ is performed based on the detection result of the winding number detector 18.

FIG. 3 is a characteristic diagram showing the roundness of the coiled thin metal tube according to the present invention after being elongated. FIG. 4 is a characteristic diagram showing the roundness after elongation of the conventional coiled thin metal tube shown for comparison with FIG. FIG.
Is a copper tube (diameter = 15.88 mm and wall thickness = 0.41 m) wound using the tube winding device having the configuration shown in FIGS. 1 and 2.
The roundness of the cross-sectional shape when m) is extended is obtained. Here, the roundness is calculated by the difference between the diameter of the cross section of the copper tube in the direction parallel to the coil axis and the diameter in the direction perpendicular to the coil axis. As is clear from FIG. 3, the cross-sectional shape of the copper tube when extended from the coil shows a substantially perfect circle. On the other hand, in FIG. 4 according to the prior art, the cross-sectional shape of the copper tube when extended from the coil is entirely flat perpendicular to the coil axis, and the difference in roundness between the inside and outside of the coil is also small. It turns out that it is big.

In the above-described embodiment, the winding number detector 18 has been described as an example of a contact type structure. In addition, a distance from a measuring point to a copper pipe surface is measured by a laser method, and a change in the distance is measured. A method of calculating the number of steps (coil diameter) from the above, a method of calculating the winding length of the copper tube from the number of rotations of the winding drum 12, or the like can also be used. Further, in the above-described embodiment, the interval between the rolls 16a and 16b is automatically set by the motor 20 based on the output of the control device 19, but may be set manually. Specifically, the control device 19 displays the roll width (the distance between the rolls) on the display device (installed near the forming roll 16).
May be displayed, and the adjustment handle 17 may be operated while looking at the displayed value.

Further, in the above-described embodiment, an example in which a copper tube is used as the coil-shaped thin metal tube has been described. However, the present invention is applicable to all thin metal tubes which can be formed in a coil shape and cause flattening. It is possible.

[0026]

As is clear from the above, according to the present invention, the flatness of the wound coil with respect to the radial direction is:
By setting the coil to be the largest on the innermost layer and smaller toward the outer layer, the tube cross section after the extension can be made a perfect circle in any layer, and the quality can be improved.

Further, the total flatness from the pre-bending step to the winding up to the stretching is grasped in advance, and based on the grasping result, the forming force for bringing the flatness to the zero state is changed to the coil-shaped thin wall before the winding. Since it is applied to the metal pipe, the cross section of the pipe after the expansion can be made a perfect circle in any layer, and the quality can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of an embodiment of a copper tube winding device according to the present invention.

FIG. 2 is a plan view of the embodiment of FIG.

FIG. 3 is a characteristic diagram showing the roundness of a coiled thin metal tube according to the present invention after being elongated.

FIG. 4 is a characteristic diagram showing the roundness of a conventional coiled thin metal tube shown in FIG.

FIG. 5 is a front view showing a schematic configuration of a conventional tube winding device for manufacturing a coil-shaped thin metal tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Copper tube 12 Winding drum 13 Straightening roll 14 Bending roll 15 Support roll 16 Forming roll 16a, 16b Roll 18 Number of turns detector 19 Control device 20 Motor

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Manabu Kagawa 3550 Kida Yomachi, Tsuchiura City, Ibaraki Prefecture Within the Tsuchiura Plant of Hitachi Cable Co., Ltd. (72) Katsuhisa Furuichi 3550 Kida Yomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Tsuchiura Plant Co., Ltd. (56) References JP-A-8-281328 (JP, A) JP-A-4-59567 (JP, A) JP-A-63-85311 (JP, U)

Claims (2)

(57) [Claims] 1. A thin-walled metal tube of circular cross-section which is wound on the winding drum in alignment coil condition of two or more layers, the ratio of the diameter D _V perpendicular to the parallel diameter D _H to the axis of the winding drum D
A coil-shaped thin metal tube wherein _V / _DH is set smaller as going from the inner layer to the outer layer. 2. A method for manufacturing a coiled thin metal tube in which a thin metal tube is wound around a winding drum in a state of two or more layers of coils, based on a curvature corresponding to a winding layer and an inner and outer diameter of the thin tube. The shape distortion at the time of winding the thin-walled tube and the shape distortion at the time of being unwound and then straightened are determined, and after applying the forming amount for canceling the shape distortion to the thin-walled tube, the winding drum is moved to the winding drum. A method for producing a coiled thin metal tube, characterized in that the tube is wound.