JPH0734936B2 - Square pipe manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method of manufacturing a corner pipes.

[0002]

2. Description of the Related Art For example, steel square pipes are widely used in rack columns having a plurality of upper and lower shelves, construction materials and the like. This square pipe is usually manufactured by roll-forming a strip-shaped metal plate by using a roll forming machine in which a plurality of rolls are arranged in tandem. Especially, in the case of a square pipe used as a support for a rack, a shelf board is used. It is common to provide a cutout hole on the side surface of the square pipe for hooking (see FIG. 1).

FIG. 13 shows a conventional method of manufacturing a square pipe provided with such a cutout hole. That is, in the prior art, first, a band-shaped metal plate body 20 is roll-formed into a round cross-section and the plate ends thereof are electric resistance welded, and then a round tube 21 formed from four sides is rolled.
Then, the rectangular tube 23 was gradually pressed to form the rectangular tube 23, and then the notch hole 25 was provided by punching 24 on the side surface of the rectangular tube 23.

[0004]

However, in the above-mentioned conventional technique, the metal plate body 20 is once formed into the round tube 21 and then formed into the square tube 23 again. There are drawbacks. Two types of roll forming machines, one for round type and one for square type, are required, resulting in high equipment cost and large occupation area. In order to prevent the occurrence of cracks in the weld line 26, conventionally, the weld line 26 must be made to pass through the center of the side surface of the square pipe. It becomes a neck for strength, and the cross-sectional rigidity cannot be increased so much.

Further, in the conventional manufacturing method, since the punching operation is performed after the rectangular tube 23 is formed, it has the following drawbacks. From the viewpoint of preventing deformation of the rectangular tube 23, the notch hole 25 cannot be provided unless the female die 27 of the punching 24 is slidably inserted into the cross section of the rectangular tube 23. Therefore, conventionally, the structure of the punching device is plural and the structure is expensive, and the facility cost is high in this respect as well. In order to increase the cross-sectional rigidity of the square pipe, there is a case where it is desired to form the cut-out hole 25 so that the cut-and-raised piece 14 is left inside the cross-section as shown in FIG. Forming such a cut-and-raised piece 14 is very difficult because the mold 27 has to be slid in the cross section of the rectangular tube 23.

On the other hand, for example, as shown in FIG.
A cutout hole 25 is provided in advance in 20 and then the metal plate body 20
It is conceivable to roll-form the round tube 21 into the rectangular tube 23 in the same manner as the above-mentioned conventional technique, thereby avoiding the conventional drawbacks in the punching operation. However, in this manufacturing method, when the round tube 21 is reshaped into the rectangular tube 23 in particular, the position shift of the notch hole 25 and the material around the notch hole 25 may buckle due to stress concentration, and the product part stops. It has the drawback of decreasing.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to be capable of easily and inexpensively manufacturing Te because very superior square pipe in terms of strength and product precision surface.

[0008]

[Means for Solving the Problems] In order to achieve the above object,
The present invention has taken the following technical means. That is, the invention according to claim 1 is a method of manufacturing a square pipe 12 in which a metal plate body 17 is roll-molded to form a square pipe 12 having a notch hole 13 in a side surface thereof. Hole 13
Is provided, and at the joints at both ends in the width direction of the metal plate body 17.
The cross-section corner portion 16 of the square pipe 12 is constructed.
In the width direction of the metal plate 17 at the beginning of roll forming
Both ends are rounded with rolls and
After roll forming directly rectangular cross-sectional shape of a flat plate state in accordance with Earle processed roll flower of <br/> constant at the subsequent roll the metal plate body 17, butt welding between the widthwise ends of the metal plate body 17 It is characterized by closing the rectangular cross section.

The invention according to claim 2 is characterized in that
The cutout holes 13 made forms as cut-and-raised pieces 14 that bulges remains
The square plate 12 on the side surface is roll-formed with the metal plate body 17.
A method of manufacturing a square pipe to be manufactured by Rukoto, before
The metal plate body 17 is formed in advance so that the cut and raised pieces 14 remain.
The cutout hole 13 is provided in the width direction of the metal plate body 17.
The cross-sectional corner portion 16 of the square pipe 12 at the end joint is
As configured, the metal plate at the beginning of roll forming
The both ends in the width direction of the body 17 are cut and raised, and the circumferential groove 18 for escape of the piece 14 is formed.
In addition to being rounded with the rolls it has,
Place the rounded metal plate 17 with the subsequent roll.
Direct rectangular cross section from flat plate according to constant roll flower
Between the two ends in the width direction of the metal plate 17 after roll-forming
Is butt-welded to close the rectangular cross section .

[0010]

According to the method of the present invention, since the metal plate body 17 is directly roll-formed from the flat plate state into a rectangular cross-sectional shape, only one roll-forming machine 5 is required, and the positional deviation of the notch hole 13 or the like does not occur. It can be molded into a predetermined cross-sectional shape. At this time, metal
The cross section of the square pipe 12 at the joints at both ends in the width direction of the plate body 17
Both ends of the metal plate body 17 in the width direction so that the corner portions 16 are configured.
Since the butt welding is performed between the
Make sure that the cutout holes 13 are properly placed on all sides.
It is possible to improve the cross-sectional strength of the square pipe 12 after welding.
Wear.

Further , during roll forming of the metal plate body 17,
Since both ends in the width direction are rounded by rolls 9 and 10,
Butt welding performed after molding
Also, such rounding is performed at the initial stage of roll forming.
Therefore, both the width direction of the metal plate body 17 can be
It has a very simple structure compared to the case where the end is rounded.
You can do the rounding process with a tool.

According to the second aspect of the invention, the first roll forming is performed.
The roll 9 that performs the above-mentioned rounding in the
Has a peripheral groove 18 for escaping the cut-and-raised piece 14 provided in advance
Therefore, the cut-and-raised piece 14 is crushed during the rounding process.
Never.

[0013]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 2 shows an outline of a square pipe manufacturing facility in which the method of the present invention is adopted. The manufacturing equipment consists of an uncoiler 1, a leveler 2 and an NC feeder in order from the left side of the figure.
3, notch press 4, roll forming machine 5, high frequency welding machine 6,
It consists of a traveling cutting device 7 and a line-out table 8 arranged in tandem.

The roll forming machine 5 comprises a pair of upper and lower rollers.
A large number of 9, 10 are provided in series, and in this embodiment, a total of 20
It has stepped rollers 9, 10. Also, high-frequency welder 6
Is mounted on the roll forming machine 5 via a slider 11 so as to be movable in the pass line direction. 3 and 4
In the above, 12 is a square pipe to be manufactured in this embodiment,
It is made of steel with a rectangular cross section and serves as a support pillar for supporting the shelf boards of the rack (not shown). This square pipe 12
In order to support the shelf board at various heights, a large number of notch holes 13 are provided at predetermined intervals on the side surface in the vertical direction.In the present embodiment, one side of the notch hole 13 has a cross section inward of the square pipe 12. The cut-and-raised piece 14 that bulges out is left.

Reference numeral 15 denotes a welding line of the square pipe 12, and in this embodiment, the welding line 15 is butt-welded so that the welding line 15 is located at the cross section corner portion 16 of the square pipe 12. next,
A method of manufacturing the square pipe 12 will be described step by step. Figure 1
As shown in FIG. 1, first, the strip-shaped metal plate body 17, which is the material of the square pipe 12, is flattened by the uncoiler 1 and the leveler 2. In this flat state, the notch hole 13 is provided at a predetermined position by the notch press 4. At this time, the cut-and-raised piece 14 is left on one side of the cutout hole 13 so as to project upward.

Thereafter, the metal plate body 17 having the cutout holes 13 is formed.
Is not a round shape as in the past, but the above
A 20-stage roll forming machine 5 roll-forms a flat plate directly into a rectangular cross-section. FIG. 5 shows a roll flower when such roll forming is performed.
O.1, NO.2 ... Indicates roll numbers.

As is apparent from FIG. 5, in the present embodiment, first, the plate end (width direction) of the metal plate member 17 is first moved by the second roll.
Both ends are rounded. This is because in the present embodiment, by forming the cross-section corner portion 16 of the square pipe 12 after forming at the plate end portion, it becomes easier to perform butt welding later, and at the beginning of roll forming, the metal plate body is formed.
The structure of rolls 9 and 10 is better if the 17 plate edges are rounded
This is because it can be simple.

That is, the middle stage of roll forming (see, for example, FIG.
8 NO.8) or late (for example, after NO.13 in FIG. 10)
Now, the metal plate body 17 has already been bent and is no longer flat.
Therefore, the plate edge of the metal plate body 17 after the bending is rounded.
The upper and lower rolls 9 and 10 have special shapes when they are processed.
Need to be redesigned. In this regard, in this embodiment, the low
The beginning of roll forming, that is, before starting full-scale roll forming
Roll both ends of the metal plate body 17 in the width direction (No. 2 in Fig. 6)
As shown in FIG.
The upper roll 9 on both sides of the step and the lower roll 10 on both sides of the groove.
It suffices if the rounded portions 9A and 10A having a predetermined shape are formed.
A metal plate body between upper and lower rolls 9 and 10 having rounded portions 9A and 10A
Rounding the widthwise ends by simply passing 17
You can

Furthermore, as described above, the welded portion (joint
Section) is arranged at the corner section 16 of the square pipe 12,
Proper location of cutouts 13 on all sides of pipe 12
Can be provided on the side surface, and, for example, in the middle of the side surface.
Cross-section of the square pipe 12 after welding compared to the case of welding
Strength is also improved. Next, after raising both ends of the metal plate body 17 to some extent by the second to eighth rolls, the ninth to twelfth rolls
Rolling is performed by bending the central portion of the metal plate body 17 so that the lower side becomes a ridge line, and thereafter, by rolling the thirteenth to sixteenth rolls so as to gradually close the cross section.

When the plate ends of the seventeenth roll are substantially in contact with each other, the plate ends are butt-welded by the high-frequency welding machine 6 arranged between the seventeenth roll and the eighteenth roll. The nineteenth and twentieth rolls are rolls for finely adjusting the cross-sectional dimension of the square pipe after the cross-section is closed. Incidentally, FIG.
12 to 12 are vertical cross-sectional views of the second, sixth, eighth, eleventh, thirteenth, sixteenth, and eighteenth rolls of the above roll flour, respectively. Of these, in FIG. 6, the upper roll 9
The peripheral groove 18 for escape of the cut- and- raised piece 14 is provided in
This is to prevent the cut-and-raised pieces 14 formed on the metal plate body 17 from being crushed.

Thereafter, the square pipe 12 roll-formed as described above is cut into a predetermined length by the traveling cutting machine 7 and is carried out onto the line out table 8. As described above, according to this embodiment, since the metal plate body 17 having the cutout holes 13 is directly roll-formed into the rectangular cross-sectional shape, only one roll forming machine 5 is required and the equipment cost can be reduced. At the same time, the roll forming can be performed without the positional deviation of the cutout hole 13 and the buckling of the peripheral material thereof, so that the square pipe 12 with the cutout hole 13 with high accuracy can be manufactured very easily.

According to the manufacturing method of this embodiment,
Since the butt welding is performed at the final stage of the roll flower, the welding line 15 of the square pipe 12 can be arranged in the cross-section corner portion 16 as described above, and the cross-sectional rigidity of the square pipe 12 after forming can be increased as much as possible. can do. Further, it is possible to roll-form the metal plate body 17 which is cut and raised on one side of the cutout hole 13 and has the piece 14 left, and there is an advantage that the cross-section loss due to the cutout hole 13 can be effectively prevented.

Furthermore, according to this embodiment, since the metal plate body 17 in the flat plate state is punched, the notch press 4 need only have a simple structure, and the facility cost can be reduced also from this point. You can The present invention is not limited to the above embodiment, when there is no need to particularly increase section stiffness of square pipes 12, the need to leave the raised pieces 14 daringly Ete switching without <br/> .

According to the method of the present invention, it is possible to manufacture not only the support pillars of the rack but also other square pipes used for various construction materials. By redesigning the roll flower, square pipes of irregular cross section can be produced. Of course, it can be molded.

[0025]

According to the first aspect of the present invention, since only one roll forming machine 5 is required, the equipment cost can be reduced, and the roll forming can be performed without causing the positional deviation of the notch holes 13 and the like. The highly accurate square pipe 12 can be manufactured very easily. In addition, both ends in the width direction of the metal plate body 17
The cross-section corner 16 of the square pipe 12 is
Butt welding between the widthwise ends of the metal plate 17
The cutout holes 13 on all sides of the square pipe 12.
Can be installed at an appropriate position,
Of square pipe 12 after welding compared to welding at
The surface strength can be improved.

Further, both ends in the width direction of the metal plate member 17 are rolled 9,
Butt that is performed after roll forming because R is processed by 10
This makes it easier to perform welding, and at the same time rounds
Is performed at the beginning of roll forming,
When rounding both ends in the width direction of the metal plate 17 at the end or later
Compared with the case of rolling
The equipment cost of the molding machine 5 can be kept as low as possible.

According to the invention described in claim 2, roll forming
When performing the above-mentioned R processing in the initial stage of
14 is stored in the escape groove 18 provided on the roll 9.
The cut-and-raised pieces 14 are crushed during the rounding process.
For this reason, the cut-and-raised piece 14 that bulges inward in the cross section
Even if it has the square pipe 12, it does not have the same raised piece 14
It can be manufactured on the same manufacturing line as the pipe 12.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a method for manufacturing a square pipe.

FIG. 2 is a side view of a square pipe manufacturing facility.

FIG. 3 is a perspective view of a square pipe.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an explanatory diagram of a roll flower.

FIG. 6 is a vertical sectional view of a second roll.

FIG. 7 is a vertical cross-sectional view of a sixth roll.

FIG. 8 is a vertical cross-sectional view of an eighth roll.

FIG. 9 is a vertical sectional view of an eleventh roll.

FIG. 10 is a vertical sectional view of a thirteenth roll.

FIG. 11 is a vertical sectional view of a 16th roll.

FIG. 12 is a vertical sectional view of an eighteenth roll.

FIG. 13 is a schematic explanatory view showing a conventional method for manufacturing a square pipe.

FIG. 14 is a schematic explanatory view showing a comparative example.

[Explanation of Codes] 9 Roll 10 Roll 12 Slider 13 Notch Hole 14 Cut and Raised Piece 16 Cross Section Corner 17 Metal Plate

Claims (2)

[Claims] 1. A square pipe (12) having a notch hole (13) on its side surface.
In the method for manufacturing a square pipe produced by roll-forming a metal plate body (17), the metal plate body (17) is provided with the notch hole (13) in advance, and the metal plate body (17) is provided. Width of
Cross-section corners of the square pipe (12) at joints on both ends in the opposite direction
So that part (16) is configured at the beginning of roll forming.
Both ends in the width direction of the metal plate body (17) are moved by rolls (9) and (10).
This is a processed metal
After roll forming directly rectangular cross-sectional shape of a flat plate state in accordance with a predetermined roll flower plate body (17) by a subsequent roll (9) (10), butt welding between the widthwise ends of the metal plate body (17) A method for manufacturing a square pipe, characterized in that a rectangular cross section is closed. 2. A cut and raised piece (14) which bulges inward of the cross section remains.
Square pipe (1) having a notch hole (13)
2) is manufactured by roll forming the metal plate body (17).
A method for manufacturing a rectangular pipe according to claim 1, wherein the metal plate body (17) is preliminarily prepared.
Notch hole (13) formed so that the cut and raised piece (14) remains
Is provided, and the joints at both ends in the width direction of the metal plate body (17)
At the corner section (16) of the square pipe (12)
The metal plate body (17) at the beginning of roll forming
The both ends in the width direction of the above are cut and raised, and the peripheral groove (18) for escape of the piece (14)
It can be rounded with the rolls (9) (10)
Then, this rounded metal plate body (17) is rolled into a subsequent roll.
(9) By means of (10), flat plate condition according to the specified roll flower
From the metal plate directly after roll forming into a rectangular cross-sectional shape
Closing the rectangular cross section by butt welding the widthwise ends of the body (17)
A method for manufacturing a square pipe, comprising: