JP6735182B2 - End press bending device for taper pipe - Google Patents

Description

The present invention relates to an end press bending device for a tapered pipe, and particularly when bending a fan-shaped flat plate material into a tapered pipe base material, presses the end of the flat plate material into the end shape of the tapered pipe base material with high precision. The present invention relates to a bending device.

Metal pipes such as steel pipes are widely used for structures such as stanchions and mechanical equipment, but recently, instead of straight pipes, tapered pipes having continuously changed pipe diameters have been used.

Conventionally, in the case of manufacturing a tapered tube, a method of manufacturing a tapered tube by forming a trapezoidal flat plate material into an annular shape by U-O pressing and welding the abutting edges has been proposed (Patent Document 1). ), multiple bending marks could remain on the tapered tube.

In addition, the three rolls are arranged at the positions of the vertices of the triangle, and the distance between the one ends of the lower two rolls is set to be smaller than the distance between the other ends, while the rolls are arranged in the longitudinal direction. It is divided into a plurality of parts, the roll part on one end side is driven at low speed, the roll part on the other end side is driven at high speed, the intermediate roll part on one end side and the other end side is driven, and two lower rolls and one roll are driven. Set the fan-shaped flat plate material between the upper roll and the upper roll, process the small diameter part of the flat plate material at one end side, process the large diameter part of the flat plate material at the high speed part, and measure the diameter from the small diameter part to the large diameter part. Has been proposed, and a bending roll device for bending a tapered pipe blank is proposed (Patent Document 2). However, in this bending roll device, since bending is performed by a plurality of divided rolls, it is easy for a step to be formed on the surface of the tapered pipe blank.

On the other hand, three rolls are arranged parallel to each other at each vertex of the triangle, a pair of front and rear pads are arranged outside two lower rolls, and a fan-shaped plate material is sandwiched between the four corner pads to form a flat plate. After the material is positioned, the pads at the four corners are retracted, the partial fan-shaped portion of the flat plate material at a predetermined angle is partially bent into an arc shape with three rolls, this material is sent in the roll width direction, and the above-mentioned operation is repeated. Accordingly, a bending roll device has been proposed in which a tapered pipe blank is bent (Patent Document 3).

JP-A-55-100816 JP, 2007-15014, A JP, 2006-159251, A

In the roll bending apparatus described in Patent Document 3, it is difficult to form a step on the surface of the taper pipe blank, but at the start of the partial bending process, the roll bending process of the starting end of the flat plate material cannot be performed, so that the starting angle of the flat plate material is large. It was necessary to bend the range to the shape of the starting end of the taper pipe blank with another device.

In view of the above problems, the present invention is such that when a fan-shaped flat plate material is bent into a tapered pipe blank, a starting end portion of the flat plate material can be accurately bent into a starting shape of the tapered pipe blank. It is an object to provide a pipe end press bending device.

Therefore, the end press bending device for a tapered tube according to the present invention is configured such that the end part of the fan-shaped flat plate material is obtained by repeating the narrow-width partial press bending process for the end part of the fan-shaped flat plate material by the female mold and the male mold. In the end press bending device of the tapered pipe that bends the part into the end shape of the taper pipe blank, the female mold has a concave mold surface that extends in the lateral width direction, and the male mold has a convex surface with an arcuate cross section. Has a shape extending in the lateral width direction, and the flat plate material is press-bent by press-fitting the die surface portion having an arcuate convex cross-section relative to the concave die surface. The male die surface portion has at least one recessed hole on the front side in the feed direction of the flat plate material with respect to the most protruding end of the die surface, and a stopper protruding by its own weight is retained in the recessed hole to prevent the stopper from coming off. The stopper protrudes by its own weight to position the starting edge of the flat plate material.

One of the features of the present invention is that a stopper is provided on the mold surface of the male mold so that it can project by its own weight, and the starting edge of the flat plate material is positioned by this stopper so that the male mold surface becomes the female mold surface. The point is that the start end portion of the flat plate material is press-bent by relatively pushing.

As a result, the starting end portion of the flat plate material can be accurately bent into the starting end portion shape of the tapered pipe blank.
When the male die is pressed against the end portion following the press-bending start end portion, the stopper is pushed into the recessed hole in the male die, so that the press-bending processing of the end portion of the flat plate material is not hindered.

The starting edge of the flat plate material can be positioned by providing at least one stopper, but it is preferable to provide a plurality of stoppers in order to position the starting edge of the flat plate material with high accuracy and stability.

The portion following the end of the flat plate material may be roll-bent or press-bent.

It is a schematic front view which shows the structure of the preferable embodiment of the press bending apparatus which concerns on this invention. It is sectional drawing which shows the structural example of the male type|mold in the said embodiment. It is a figure which shows the cross-sectional shape of the concave mold surface of the female mold|type in the said embodiment. It is a figure which shows typically the partial bending process with respect to the edge part of the flat plate material of a fan shape in the said embodiment. It is a figure which shows the movement of the male type|mold in the said embodiment typically.

Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 5 show a preferred embodiment of a press bending apparatus for a tapered tube according to the present invention. In the figure, a press bending device is installed on the floor surface, and the press bending device is provided with a gate-shaped frame 10, and the gate-shaped frame 10 connects the upper ends of the left and right leg frame parts 10A with a connecting frame part 10B. It is in a state.

A hydraulic press 11 is mounted on the connecting frame portion 10B of the gate-shaped frame 10, and a male die 12 is attached to the left and right leg frame portions 10A so as to be vertically slidable so that the male die 12 can perform a pressing operation. A die surface portion 12A having an arcuate convex shape is formed to extend in the lateral width direction, and a female die 13 is arranged below the male die 12 so as to face it.

Further, the base block 17 is installed on the floor surface, the female die 13 is mounted on the base block 17, and the female die 13 has a concave die surface 13A facing the die surface 12A of the male die 12. Is formed so as to extend in the lateral width direction, and a narrow-width arc-shaped partial press bending process can be performed on the flat plate material 30 by the concave die surface 13A of the female die 13 and the arcuate convex die surface 12A of the male die 12. It is supposed to be done.

Further, a plurality of recessed holes 12B are formed on the mold surface 12A of the male mold 12 in the forward direction of the flat plate material 30 with respect to the most protruding end 12D thereof at predetermined intervals in the lateral width direction. Has a built-in stopper pin 12C protruding by its own weight, and a flange-shaped retaining portion 12E having an enlarged diameter is formed at an upper end portion of the stopper pin 12C. The retaining portion 12E is formed with a step portion 12F of the recessed hole 12B. The stopper pin 12C is adapted to come into contact with the stopper pin 12C so that the stopper pin 12C projects downward due to its own weight to position the starting edge 30A of the flat plate material 30.

On the other hand, the mold surface 13A of the female die 13 is formed in a plurality of steps, and can be selected according to the bending angle of the end portion of the flat plate material 30. One side of the inner edge of the upper end of the concave portion 13A in cross section of the female die 13 The starting end portion 30A of the fan-shaped flat plate material 30 is mounted on the stepped portion of, and the narrow-width arc-shaped partial press bending process is performed.

Further, the female die 13 is elastically held by the spring member 14 with respect to the base block 17, and is provided so that the die surfaces are inclined by the wedge members 15 on both sides. The piston rod of the cylinder 16 is connected.

When press-bending the end portion of the fan-shaped flat plate material 30, when the rod of the cylinder 16 on the side corresponding to the inside of the fan-shaped flat plate material 30 of the male mold 12 is extended, the female mold 13 has a maximum range of 5°. Can be tilted at an angle.

In that state, the flat plate material 30 is fed by the feed rollers 20 and 21 on the large diameter side in a large amount and on the small diameter side in a small amount so as to straddle the die surface 13A of the female die 13 as shown in FIGS. On the other hand, when the left and right rods of the hydraulic press 11 are synchronously extended and the male die 12 is moved downward, stopper pins 12C project downward on the die surface 12A of the male die 12 as shown in FIG. The starting edge 30A of the fed flat plate material 30 is positioned by hitting the stopper pin 12A as shown in FIG. 5A, and when the male die 12 is further moved downward, the starting edge portion of the flat plate material 30 is moved. Is mounted in an appropriate stepped portion of the mold surface 13A of the female mold 13 in a state of being positioned, and when the male mold 12 is pushed further downward, the stopper pin 12A is pushed by the male mold 12 downwardly. It is pushed into the recessed hole 12B, and the starting edge portion of the flat plate material 30 is partially press-bent into an arc shape by the die surface 12A of the male die 12.

At that time, since the female die 13 is inclined, the side corresponding to the inner side of the fan-shaped flat plate material 30 has a small-diameter circular arc shape, the side corresponding to the outer side has a large-diameter circular arc shape, and both sides are continuous. Partial press bending is carried out, and thereby partial bending is performed in an arc shape.

When the partial press bending of the starting end portion of the flat plate material 30 is completed, the flat plate material 30 is fed by the feed rollers 20 and 21 so that the next scoring line 30B of the flat plate material 30 is on the mold surface 13A of the female die 13, The male die 12 is pressed downward.
At this time, as shown in FIG. 5B, the flat plate material 30 is located below the stopper pin 12C, but when the male die 12 is pressed downward, the stopper pin 12C is recessed into the male die 12. Since it is pushed into 12B, the press bending process is not hindered, and the flat plate material 30 is partially bent into an arc shape.

When the flat plate material 30 is fed by the feed rollers 20 and 21 so that the scoring line 30B next to the flat plate material 30 is on the mold surface 13A of the female mold 13, the male mold 12 is pressed downward, as shown in FIG. ), the flat plate material 30 is partially bent in an arc shape without causing any hindrance to the press bending process, and the partial arc shape bending process is repeated while feeding the flat plate material 30 one after another.

By repeating the partial arc-shaped bending process on the opposite end of the fan-shaped flat plate material 30, both ends of the flat plate material 30 can be bent to the end shape of the tapered pipe blank.

The intermediate portion of the flat plate material 30 can be press-bent into the tapered pipe blank by the above-described press bending work, but the present invention is not limited to this, and for example, the shape of the tapered pipe blank can be formed by a known roll bending work. It can also be bent.

12 Male type 12A Mold surface 12B Recessed hole 12C Stopper pin 13 Female type 13A Mold surface 30 Flat plate material 30A Starting edge

Claims (2)

A taper that bends the end of a fan-shaped flat plate material into the end shape of a tapered pipe blank by repeating the narrow-width partial press bending process on the end of the fan-shaped flat plate material using a female die and a male die. In the pipe end press bending device,
The female mold (13) has a concave mold surface (13A) extending in the lateral width direction,
The male mold (12) has a shape surface part (12A) having a convex arcuate cross section extending in the lateral width direction, and the mold surface part (12A) having a convex arcuate cross section has a shape with respect to the concave mold surface (13A). While the flat plate material (30) is partially press-bent by being relatively pushed in,
The male die (12) has at least one recessed hole (12B) in the die surface portion (12A) on the front side in the feeding direction of the flat plate material (30) with respect to the die surface most protruding end (12D). A stopper (12C) protruding by its own weight is built into the hole (12B) so as to prevent the stopper from falling out and the stopper (12C) protrudes by its own weight to position the starting edge (30A) of the flat plate material (30). An end press bending device for a tapered pipe, which is characterized by: The end press bending apparatus for a tapered tube according to claim 1, wherein the male die (12) and the female die (13) are adapted to partially press-bend an intermediate portion of the flat plate material (30).

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