JPH0810833A - Apparatus for producing tapered square pipe - Google Patents

Abstract

PURPOSE:To facilitate execution of knock-out of a tapered square pipe after drawing by rotationally driving a stopper of, for example, a square shape arranged atop a male mold by a rotational driving mechanism via a revolving shaft penetrating the central part of the male mold. CONSTITUTION:A blank square pipe 1a is drawn to the tapered square pipe by the male mold 18 and a female mold 15 when the blank square pipe 1a is put on the male mold 18 and the female mold 15 is lowered. At this time, the square angle part of a stopper 21 projects outward from the outer peripheral surface of the male mold 18 when the stopper 21 is rotated, for example, 45 deg. via the revolving shaft 20 by the rotational driving mechanism 22. On the other hand, the tapered angle pipe formed by drawing is eventually press welded to the inside surface of the female mold 15. Then, the tapered angle pipe tends to ascend together with the female mold 15 at the time of ascending of the female mold 15, but the ascending thereof is stopped by the stopper 21 projecting outward from the outside peripheral surface of the male mold 18 and, therefore, the tapered angle pipe peels from the inside surface of the female mold 15 and falls onto the male mold 18. The tapered angle pipe is thus automatically knocked out by the stopper 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tapered square tube manufacturing apparatus for manufacturing a truncated square pyramid-shaped tapered rectangular tube suitable for use as a connecting portion of rectangular steel tube columns having different diameters, and more particularly, when a pressing operation is performed. The present invention relates to a knockout mechanism for separating a tapered rectangular tube formed by drawing from a female mold.

[0002]

2. Description of the Related Art In a steel structure building, when a rectangular steel tube column having a diameter smaller as it goes upstairs is used, it is generally used to connect square tubes having different diameters as shown in FIG. A tapered rectangular tube 1 having a pyramid shape is used. Conventional methods for manufacturing this kind of tapered rectangular tube 1 include casting, forming by welding and connecting four trapezoidal plate members, and bending one or two plate members cut into a predetermined development view shape. For example, there is one in which the abutting parts are welded and connected after being formed into a tapered rectangular tube shape. Further, there is a method of forming by drawing with a metal mold having a truncated square pyramidal male mold and a female mold corresponding thereto (the method of Japanese Patent Application No. 4-223643 adopts this method).

A method other than the drawing using the above-mentioned mold is
The process is complicated and the manufacturing is not easy. The draw forming method using the die has a simple process, but since the draw forming is performed with an extremely large pressing force when the draw forming is performed, the tapered square tube drawn into the truncated quadrangular pyramid shape has an inner surface of the female die. There is a problem that it is not easy to crimp the taper square tube out of this female mold by strongly crimping. Therefore, a knockout hydraulic cylinder is installed in the center of the ram of the press machine.
A method of pushing the knockout block into the female die by this hydraulic cylinder and knocking out the tapered rectangular tube is conceivable. However, this method is difficult to perform using an existing press machine because the hydraulic cylinder is provided. In addition to the pressing operation for drawing, a knockout process using a hydraulic cylinder is required separately, so the total process time becomes longer and the manufacturing efficiency decreases.

For these reasons, the inventors of the present invention developed a taper rectangular tube manufacturing apparatus having a simple structure capable of automatically knocking out in accordance with the pressing operation, and filed a patent application (Japanese Patent Application No. Hei 6 (1994)). -27474). This taper rectangular tube manufacturing apparatus will be described with reference to FIGS. 7 and 8. The taper rectangular tube manufacturing apparatus 2 is, for example, a ram 3 of a hydraulic press machine.
A female die 5 fixed via a female die holder 4 and a male die 8 fixed to a pedestal 6 of the press via a male die holder 7. A stopper is provided near the upper end of the male die 8. 9 is fitted in such a manner that it can be projected and retracted in the horizontal direction (in the illustrated example, it is projected and retracted in the diagonal direction), and the built-in spring 10 urges the stopper 9 outward to hold it in a protruding state. When the female die 5 descends during the pressing operation, the stopper 9 is pushed horizontally by the inner surface of the female die 5 and the spring 1
After the material square tube 1a is formed into a tapered square tube against the reaction force of 0, and the female die 5 rises, the stopper 9 is again acted by the reaction force of the spring 10. Since it protrudes from the outer peripheral surface of the male die 8, the female die 5 is pressed against the inner surface of the female die 5.
It hits the upper end of the tapered rectangular tube, which knocks out the tapered rectangular tube.

[0005]

The knockout mechanism in the above-mentioned tapered square tube manufacturing apparatus 2 is the ram 3 of the press machine.
Since the knockout is automatically performed by using the ascending force of the press, the efficiency of the press work can be improved with a simple configuration, but the space above the male die 8 is limited, so let's manufacture it. Depending on the size of the tapered rectangular tube, it may be difficult to incorporate the spring 10 having the desired performance into the male mold 8, and it may be difficult to provide the stopper 9 having the desired strength. In addition, since the spring 10 is used, the stopper 9 does not appear and disappear smoothly due to deterioration of the performance of the spring.
There may be cases where the knockout behavior becomes uncertain.

The present invention has been made in view of the above circumstances, and in the draw forming of a tapered rectangular tube, knockout can be performed easily and efficiently, and there is less restriction on the space for arranging the stopper for performing knockout. An object of the present invention is to provide a taper square tube manufacturing apparatus capable of ensuring sufficient strength for a stopper and reliably performing a knockout operation.

[0007]

SUMMARY OF THE INVENTION In a taper rectangular tube manufacturing apparatus of the present invention for solving the above-mentioned problems, a material rectangular tube is tapered by drawing a truncated square pyramidal male mold and a corresponding female mold. A taper rectangular tube manufacturing apparatus for manufacturing a rectangular tube, comprising: a rotation axis that vertically penetrates a central portion of the male die, and a square slightly smaller than a square on an upper end surface of the male die when viewed from above, A knockout mechanism including a stopper fixed to the upper end of the shaft and arranged on the upper part of the male mold, and a rotary drive mechanism for rotating the rotary shaft by a predetermined angle is provided.

[0008]

In the apparatus for manufacturing a tapered rectangular tube having the above-mentioned structure, the stopper which is, for example, quadrangular when viewed from the upper surface is usually in a state in which the quadrangle fits within the quadrangle of the male upper end surface. When the male square is covered with the material square tube and the female die is lowered, the material square tube is drawn into a tapered square tube by the male and female dies. At this time, when the stopper is rotated by, for example, 45 ° via the rotation shaft by the rotation driving mechanism, the quadrangular corner of the stopper protrudes outward from the outer peripheral surface of the male mold. On the other hand, the tapered rectangular tube formed by drawing is crimped to the inner surface of the female mold. Therefore,
When the female die rises, the tapered rectangular tube tries to rise together with the female die, but since the above-mentioned stopper protruding outward from the outer peripheral surface of the male die stops the rise, it separates from the inner surface of the female die. It falls on the mold. In this way, the tapered rectangular tube is automatically knocked out by the stopper.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front sectional view of a tapered rectangular tube manufacturing apparatus 12 of an embodiment of the present invention, and FIG. 2 is a plan view showing only the male side of the tapered rectangular tube manufacturing apparatus 12. This taper rectangular tube manufacturing apparatus 12 is fixed to a ram 13 of a hydraulic press machine via a female holder 14 and a pedestal 16 of the press machine via a male holder 17, for example. The male mold 18 and the knockout mechanism 19 provided on the male mold 18 side. In this embodiment, the tapered rectangular tube 1 shown in FIG. 6 is manufactured, and a material rectangular tube before drawing is indicated by 1a.

The female die 15 has a truncated quadrangular pyramid-shaped inner surface 15 substantially equal to the outer surface shape of the tapered rectangular tube 1 to be manufactured.
have a. The male die 18 has a truncated quadrangular pyramid-shaped outer peripheral surface which is substantially equal to the inner surface shape of the tapered rectangular tube 1 to be manufactured. The knockout mechanism 19 includes a rotating shaft 20 that penetrates a circular through hole 18a vertically formed in the center of the male die 19.
And a stopper 21 fixed to the upper end of the rotary shaft 20 and formed on the upper end of the male mold 18 to form a rectangular shape slightly smaller than the rectangular shape of the upper end surface of the male mold 18, and rotating the rotary shaft 20 by, for example, 45 °. And a rotary drive mechanism 22 for rotating the same. The side surface of the stopper 21 is inclined to substantially match the inclination of the side surface of the male die 18. The male holder 17 has a leg portion 17a and a space is formed on the back side thereof,
The threaded portion at the lower end of the rotating shaft 20 extending to the back side is provided with a stopper 21 and the rotating shaft 20 against the knockout load.
A nut 25 is attached together with a washer 26 to prevent the screw from coming off. Then, the rotary drive mechanism 22 is
Below the male holder 17, an air cylinder device 24 is horizontally attached to the leg portion 17a.
The piston rod 24a of No. 4 is connected to a position eccentric from the shaft center of the lower end of the rotary shaft 20 extending below the male holder 17.

Next, the procedure for manufacturing the tapered rectangular tube 1 by the above-described tapered rectangular tube manufacturing apparatus 12 will be described with reference to FIGS. The taper square tube to be manufactured by the taper square tube manufacturing apparatus of the present invention is usually a large size such as the material square tube 1a having a plate thickness of 12 mm × length 250 mm × width 250 mm. It is advisable to perform drawing forming of the final shape separately. 1 to 5 show the first pressing operation. FIG. 1 shows a state before the pressing operation. The piston rod 24a of the air cylinder device 24 is contracted, and the stopper 21 is in a state in which the quadrangle of the contour thereof fits within the quadrangle of the upper end surface of the male die 18. ing. The material square tube 1 a is put on the male mold 18 to cover the male mold 18.

Next, the press machine is operated to move the female die 15 together with the ram 13 and the female die holder 14 as shown in FIG.
To lower. In the first pressing operation, the stroke of the ram 13 is stopped at an intermediate position as shown in the drawing, and the raw material rectangular tube 1a is drawn to an intermediate stage to obtain an intermediate stage tapered rectangular tube 1 '.

Then, the air cylinder device 24 is operated to extend the piston rod 24a, rotate the rotary shaft 20 by 45 °, and rotate the stopper 21 integrated with the rotary shaft 20 by 45 °, as shown in FIG. Square shaped stopper 2
The first corner portion 21 a slightly projects outward from the outer peripheral surface of the male die 18. On the other hand, the tapered rectangular tube 1'formed by drawing is a female mold 15
When the female die 15 rises because it is crimped to the inner surface 15a, the tapered rectangular tube 1 ′ tries to rise together with the female die 15, but as shown in FIG. 4, it projects outward from the outer circumferential surface of the male die 18. Since the rising is stopped by hitting the corner portion 21a of the stopper 21, the tapered rectangular tube 1'is separated from the inner surface 15a of the female die 15 and drops onto the male die 18, as shown in FIG. In this way, the tapered rectangular tube 1'is automatically knocked out by the stopper 21. Note that when drawing is performed, usually, as shown in FIG. 2B, a slight wave due to buckling is generated at each side of the upper end of the material, but this wave widens the thickness stopped by the stopper 21. Since it becomes larger than the plate thickness, it is convenient for the stopper 21 to knock out the tapered rectangular tube 1 ′. This wave portion will be removed later by cutting near the upper end. Then, the air cylinder device 24 is activated to operate the piston rod 2
4a is contracted, and the rotary shaft 20 and the stopper 21 integrated with the rotary shaft 20 rotate in the opposite direction by 45 °, and the original state shown in FIG. 1 is restored.

Then, by the second pressing operation, the drawing is performed to further lower the female die 15 from the previous time.
The knockout operation at this time is the same as described above. Further, the final truncated square-shaped tapered rectangular tube 1 is obtained by the third pressing operation, and the knockout operation in this case is also the same as described above. In addition, in order to reduce the forming load and the knockout load, it is preferable to apply the lubricating oil to the inner surface 15a of the female die 15 before each pressing operation.

In the above description, the stopper 21 is rotated by 45 °, but it is not actually necessary to control the rotation of the stopper 21 to a predetermined angle such as 45 °. Even if the extension amount of the piston rod 24a of the air cylinder device 24 is not controlled and the stopper 21 is simply extended to rotate in one direction, the stopper 21 abuts on the inner surface of the female die 15 and the rotation is stopped. It will definitely stick out. When the draw forming is divided into a plurality of pressing operations as in the embodiment, since the diameter of the upper end of the tapered rectangular tube is different in each step, the female mold 15 is used as described above.
The method of rotating the inner surface 15a until it hits the inner surface 15a is more suitable.

Further, in the embodiment, the shape of the stopper 21 is a quadrangle when viewed from the upper surface, but it is not always necessary to have a quadrangle. In short, any shape may be used as long as there is a portion corresponding to the corner of the quadrangle and the portion can slightly project outward from the outer peripheral surface of the male die 18 when rotated. Further, in the embodiment, the case where the draw forming is performed by dividing the press operation into a plurality of times has been described, but it is naturally applicable to the case where the final shape of the tapered rectangular tube is formed by one press operation. Also,
In the above-mentioned embodiment, as shown in FIG. 6, the case where the tapered rectangular tube 1 whose four surfaces have the same inclination is drawn is described.
Tapered rectangular tube with a two-sided diaphragm in which two surfaces are inclined and the other two surfaces are vertical,
Alternatively, the present invention can be applied to a tapered rectangular tube having a three-sided diaphragm in which three surfaces are inclined and the other surface is vertical.

[0017]

According to the present invention, a simple structure in which, for example, a rectangular stopper disposed on the upper surface of a male die is rotationally driven by a rotational drive mechanism via a rotary shaft that penetrates the center of the male die, It has become possible to easily knock out a tapered rectangular tube after drawing. Further, since the press machine itself does not need to be specially modified such as providing a knockout hydraulic cylinder, the present invention can be easily applied to an existing press machine. Since this knockout is automatically performed during the press operation, it is extremely efficient without requiring an extra step for knockout.

The stopper is arranged on the upper surface of the male mold,
Since the only part that fits into the male mold is the rotating shaft, there are few restrictions on the space for providing the stopper, and sufficient strength can be secured for the stopper. Therefore, there is no fear that the present invention cannot be applied depending on the size of the tapered rectangular tube to be manufactured. Further, since the spring is not used to drive the stopper but is driven by a cylinder device or the like, there is no problem such as deterioration of the performance of the spring, so that the knockout operation can be reliably performed.

[Brief description of drawings]

FIG. 1 shows a mode before a pressing operation is started in a process of manufacturing a tapered rectangular tube by a tapered rectangular tube manufacturing apparatus according to an embodiment of the present invention. FIG. 1A is a front sectional view of the tapered rectangular tube manufacturing apparatus. The figure and the same figure (b) are plan views showing only the male side.

2 shows a step following FIG. 1, wherein FIG. 2A is a front sectional view of a tapered rectangular tube manufacturing apparatus, and FIG. 2B is a plan view showing only a male side.

3A and 3B show steps following FIG. 2, wherein FIG. 3A is a front sectional view of the tapered rectangular tube manufacturing apparatus, and FIG. 3B is a plan view showing only the male mold side.

4A and 4B show steps following FIG. 3, wherein FIG. 4A is a front sectional view of the tapered rectangular tube manufacturing apparatus, and FIG. 4B is a plan view showing only the male mold side.

FIG. 5 shows a state in which the first pressing operation is completed in a stage subsequent to FIG. 4, where FIG. 5 (a) is a front sectional view of the tapered rectangular tube manufacturing apparatus, and FIG. 5 (b) is a male side. It is a top view which shows only.

FIG. 6 is a perspective view showing an example of a tapered rectangular tube to be manufactured by the tapered rectangular tube manufacturing apparatus of the present invention.

FIG. 7 is a front sectional view showing a conventional tapered rectangular tube manufacturing apparatus.

FIG. 8 is a plan view of the tapered rectangular tube manufacturing apparatus of FIG.

[Explanation of symbols]

 1 Tapered Square Tube 1a Material Square Tube 1'Intermediate Stage Tapered Square Tube 12 Tapered Square Tube Manufacturing Device 15 Female Model 15a Female Inner Surface 16 Press Stand 17 Male Holder 18 Male 18a Through Hole 19 Knockout Mechanism 20 Rotating shaft 21 Stopper 22 Rotational drive mechanism 24 Cylinder device 24a Piston rod

Claims (3)

[Claims] 1. A taper rectangular tube manufacturing apparatus for manufacturing a tapered rectangular tube by drawing a raw material rectangular tube with a truncated square pyramid male mold and a female mold corresponding thereto, and a center of the male mold. It has a rotation axis that vertically penetrates the part and a contour that fits within the quadrangle of the upper end surface of the male die when viewed from above, and has a shape that partially protrudes from the outer peripheral surface of the male die when rotated by a predetermined angle. A stopper fixed to the upper end of the rotating shaft and arranged on the upper part of the male mold,
A tapered rectangular tube manufacturing apparatus comprising a knockout mechanism including a rotary drive mechanism that rotates the rotary shaft by a predetermined angle. 2. The tapered rectangular tube manufacturing apparatus according to claim 1, wherein the stopper has a rectangular shape which is slightly smaller than the rectangular shape of the upper end of the male die when viewed from the upper surface. 3. The rotary drive mechanism has a cylinder device arranged horizontally below the male mold, and a piston rod of the cylinder device extends downward from the male mold from an axis of a lower end portion of the rotary shaft. The tapered rectangular tube manufacturing apparatus according to claim 1, wherein the tapered rectangular tube manufacturing apparatus is configured to be connected to an eccentric position.