JP3578320B2 - Tube forming method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming a tube. The molding method of the present invention is suitable for use in producing a catalyst container connected to an exhaust gas pipe.
[0002]
[Prior art]
For example, a spinning drawing apparatus described in JP-A-9-112259 is known as an apparatus for manufacturing an integrally molded catalyst container. In this processing apparatus, as shown in FIG. 7, the chuck 30 holds the pipe W extending in the direction of the axis O, so that the opening Wa of the pipe W projects horizontally. The chuck 30 is fixed to a rotation shaft 31a of a motor 31 that rotates in accordance with the axis O, whereby the pipe W is rotatable around the axis O. A vertically movable table 33 is provided above the opening Wa of the pipe W so as to be vertically movable by a hydraulic cylinder 32, and a horizontally movable table 35 is provided in the vertically movable table 33 so as to be horizontally movable by a hydraulic cylinder 34. . The horizontal movable table 35 is provided with a roller 37 rotatable around a pivot P parallel to the axis O of the tube W via a bracket 36.
[0003]
When the opening Wa of the pipe W is drawn into a funnel by this processing apparatus, the hydraulic cylinders 32 and 34 are controlled while rotating the pipe W around the axis O by the motor 31 so that the opening Wa of the pipe W is formed. The roller 37 is pressed and gradually moved in the direction of the axis O away from the chuck 30 side. In this way, the distance between the axis O and the pivot P is reduced while the roller 37 is relatively rotated with respect to the pipe W, and as shown in FIG. Can be formed. The product thus obtained can be used as a catalyst container.
[0004]
According to this processing device, the catalyst container can be obtained without performing the conventional welding. For this reason, it is possible to eliminate the distortion due to the heat effect at the time of welding, and to reliably prevent the exhaust gas from leaking without necessarily requiring the troublesome inspection by the leak test as in the related art. it can. Further, in this catalyst container, the exhaust gas can also flow smoothly. Thus, according to this processing apparatus, a high-performance catalyst container can be manufactured at low cost.
[0005]
[Problems to be solved by the invention]
However, in the above-mentioned conventional processing apparatus, as shown in FIG. 7, only one roller 37 is provided outside the pipe W, and as shown in FIGS. Although it is possible to perform a funnel-shaped drawing process, that is, a contraction tube forming process, a pipe expansion process opposite to this can not be performed.
[0006]
Further, even if it is possible with this processing apparatus to perform the contraction tube processing, if the distance between the axis O of the pipe W and the pivot axis P does not change at the same position in the direction of the axis O, the roller 37 can be used. 8 is limited to a simple contraction process in which the center of revolution coincides with the axis Q of the constricted portion Wb, and the axis Q of the constricted portion Wb is concentric with the axis O of the tube W as shown in FIG. Would. In this regard, if the distance between the axis O of the tube W and the pivot P can be changed at the same position in the direction of the axis O, the revolving center of the roller 37 does not coincide with the axis Q of the constricted tube portion Wb. As shown in FIG. 9, although it is considered that the axis Q of the constricted tube portion Wb can be eccentrically parallel to the axis O of the tube W, the constricted tube portion Wb of the original tube W still remains. It cannot be located outside the inner diameter.
[0007]
Further, in this processing apparatus, since the axis O of the pipe W and the pivot P are always maintained in parallel, as shown in FIGS. 8 and 9, the axis O of the pipe W and the axis of the contracted tube portion Wb. The center Q coincides or is simply eccentric in parallel, and the axis O of the tube W and the axis Q of the constricted portion Wb cannot have an angle.
The present invention has been made in view of the above conventional situation, and in addition to a simple contracted tube, the contracted tube portion is located outside the inner diameter of the original tube, or the axial center of the contracted tube portion is reduced. It is an object of the present invention to provide a method for forming a tube which can have an angle with respect to the axis of the tube, and which can also perform various expansions.
[0008]
[Means for Solving the Problems]
The method of forming a pipe according to the present invention comprises, for a pipe extending in the axial direction, forming a pair with a first roller provided rotatably around a first pivot outside the pipe, and forming a pair with the first roller. While rotating one or both of a second roller rotatably provided around a second pivot parallel to the first pivot in the pipe while contacting the pipe with the second roller, the shaft center and the second roller are rotated. By reducing or enlarging the distance between the first pivot and the second pivot and moving the first roller and the second roller in the first pivot and the second pivot directions, the tube is moved to the first roller or the second pivot. It is characterized in that the second roller performs a contraction process or a tube expansion process .
In a preferred embodiment, the tube is contracted or expanded while the tube is sandwiched between the first roller and the second roller.
[0009]
In this molding method, the distance between the axis and the first pivot is reduced, so that the first roller provided outside the tube forms a contracted tube portion in the tube. At this time, if the distance between the axis and the second pivot is reduced to the same extent, the second roller provided in the pipe can enhance the formability of the constricted tube portion. On the other hand, by increasing the distance between the axis and the second pivot, the second roller provided in the tube forms an expanded portion in the tube. At this time, if the distance between the axis and the first pivot is increased to the same extent, the first roller provided outside the pipe can enhance the formability of the expanded portion.
[0010]
Further, in this molding method, unless the distance between the axis of the tube and the first or second pivot is changed at the same position in the axial direction, the center of revolution of the first and second rollers and the axis of the molded part are not changed. It is possible to perform a simple contraction or expansion process so that the axis of the molded portion coincides with the axis of the original tube and is concentric. On the other hand, if the distance between the axis of the pipe and the first or second axis is changed at the same position in the axial direction, the revolving center of the first and second rollers does not coincide with the axis of the molded part, and the molding is performed. The axis of the part can be eccentric parallel to the axis of the original tube. At this time, the molded portion may be located outside the inner diameter of the original tube.
[0011]
Further, in this molding method, if the axis of the tube and the first and second pivots are maintained parallel, the axis of the molded part and the axis of the original tube coincide with each other or simply. It will be eccentric in parallel .
Therefore, in the molding method of the present invention, in addition to a simple contracted tube, a contracted tube whose contracted tube portion can be located outside the inner diameter of the original tube, and various expanded tubes are also possible. Therefore, the degree of freedom in design is improved.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the embodiment, the molding apparatus shown in FIG. 1 is used. In this molding apparatus, as shown in FIG. 1, an arc-shaped guide 20a is formed on a side surface of a first base 20, and a slider 1 containing a first motor (not shown) is engaged with the guide 20a. I have. A second motor 2 is fixed to a front surface of the slider 1, and a ball screw 3 extending in a vertical direction is fixed to a rotation shaft of the second motor 2. A chuck 4 that rotates about the axis O by a third motor (not shown) is screwed to the ball screw 3 so as to be vertically movable. A tube W extending in the direction of the axis O is held by the chuck 4, so that the opening Wa of the tube W projects horizontally.
[0013]
On the other hand, a fourth motor 6 is fixed on the second base 5 facing the first base 20 in the horizontal direction, and a ball screw 7 extending in the horizontal direction is fixed on the rotation shaft of the fourth motor 6. Have been. A fifth motor 8 is screwed into the ball screw 7, and a bracket 9 is fixed to a rotation shaft of the fifth motor 8. A sixth motor 10 is fixed to the bracket 9, and a ball screw 11 extending in a vertical direction is fixed to a rotation shaft of the sixth motor 10. A slide member 12 is screwed to the ball screw 11. The slide member 12 includes a first rod 16 extending horizontally a tube W outside, and a second rod 17 extending horizontally within the tube W is eclipsed set. The first rod 16 has a nut portion 15 in the middle, and can be moved up and down in parallel. At the tip of the first rod 16, a first roller 18 that can be driven around the first pivot axis P <b> 1 in the same direction as the direction in which the first rod 16 extends is provided. A second roller 19 is provided that can be driven around the second pivot P2 in the same direction as the direction in which the roller extends. An eighth motor 13 is also fixed to the bracket 9, and a ball screw 14 extending in the vertical direction is fixed to the rotation shaft of the eighth motor 13, and a nut 15 is screwed to the ball screw 14. Have been combined.
[0014]
In the molding apparatus configured as described above, first, the eighth motor 13 is driven to rotate forward to widen the gap between the first roller 18 and the second roller 19, and in this state, the first roller 18 is moved out of the pipe W. And the second roller 19 is positioned in the tube W. Then, while the eighth motor 13 is driven to rotate in the reverse direction, the sixth motor 10 is driven to rotate in the forward direction, and the first roller 18 and the second roller 19 sandwich the tube W. Then, while rotating the pipe W around the axis O by the third motor, the first roller 18 and the second roller 19 are pressed against the opening Wa of the pipe W, and gradually moved in the direction of the axis O moving away from the chuck 4 side. Let it.
[0015]
At this time, by driving the sixth motor 10 in reverse to reduce the distance between the axis O and the first pivot P1 and the second pivot P2, the sixth motor 10 is provided outside the pipe W as shown in FIG. One roller 18 forms a contracted tube portion Wb in the tube W. At this time, the second roller 19 provided in the tube W enhances the formability of the contracted tube portion Wb.
Then, the sixth motor 10 is driven to rotate forward to increase the distance between the axis O and the first and second pivots P1 and P2, so that the second roller 19 provided in the pipe W is attached to the pipe W. An expanded portion Wc is formed. At this time, the first roller 18 provided outside the tube W enhances the formability of the expanded portion Wc.
[0016]
Also, at the same position in the direction of the axis O, the sixth motor 10 is stopped, and unless the distance between the axis O of the tube W and the first and second pivots P1 and P2 is changed, the contracted portion of the tube W Simple tube reduction processing and pipe expansion processing in which the axis Q of the pipe Wb and the axis Q of the expanded section Wc are concentric with the axis O of the pipe W are possible. Further, the axis O of the tube W is maintained parallel to the first pivot P1 and the second pivot P2, and the axis O of the tube W coincides with the axis Q of the contracted tube portion Wb or the expanded tube portion Wc.
[0017]
Also, at the same position of the axis O direction, a sixth motor 10 rotates forward driving and reverse driving, if changing the distance between the axis O and the first pivot P1 and the second pivot P2 of the tube W, FIG. 3 As shown in FIG. 4, the axis Q2 of the eccentric portion We having the same diameter can be eccentrically parallel to the axis O of the original tube W. At this time, the eccentric portion We having the same diameter may be located outside the inner diameter of the original tube W.
[0018]
Further, as shown in FIG. 5, the contracted tube portion Wb is formed shortly only by the first roller 18 on the way, and then the first motor is driven to swing the slider 1 along the guide 20a of the first base 20. with elimination of the axis O of and pipe W and the first pivot P1 and the second pivot P2 in parallel, reducing the distance between the axis O and the first pivot P1 and the second pivot P2. Thereby, the contracted tube portion Wf in which the axis Q3 is inclined can be formed.
Therefore, according to the molding method of the embodiment, not only simple contraction, but also complicated contraction, simple expansion, and complicated expansion are possible. Therefore, the degree of freedom in design is improved.
[0019]
As shown in FIG. 6, the monolithic catalysts W5 and W6 are respectively housed therein, and then the catalyst containers W1 and W2 are formed. Is completed.
[Brief description of the drawings]
FIG. 1 is a side view of a tube forming apparatus according to an embodiment.
FIG. 2 is a side view of a catalyst container obtained in the embodiment.
FIG. 3 is a side view of a catalyst container obtained in the embodiment.
FIG. 4 is a side view of a catalyst container obtained in the embodiment.
FIG. 5 is a side view of the catalyst container obtained in the embodiment.
FIG. 6 is a side view of a catalytic converter using a catalyst container.
FIG. 7 is a side view of a conventional spinning drawing apparatus.
FIG. 8 is a side view of a catalyst container obtained in a conventional form.
FIG. 9 is a side view of a catalyst container obtained in a reference embodiment.
[Explanation of symbols]
W: pipe P1: first pivot P2: second pivot 18: first roller 19: second roller

Claims (2)

A first roller provided rotatably about a first pivot outside the pipe with respect to the pipe extending in the axial direction, forming a pair with the first roller, and being parallel to the first pivot inside the pipe; The distance between the axis and the first and second pivots while relatively rotating one or both of the second rollers provided rotatably about the second pivot while contacting the pipe. By reducing or enlarging the first roller and the second roller in the direction of the first pivot and the second pivot, the pipe is contracted by the first roller or the second roller. A method for forming a pipe, comprising expanding the pipe. The method for forming a pipe according to claim 1, wherein the pipe is contracted or expanded while the pipe is sandwiched between the first roller and the second roller.

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