JPS62207514A - Manufacture of cylindrical tube - Google Patents

Abstract

PURPOSE:To facilitate automatization of manufacturing processes for cylindrical tubes by prebending both edges in the axial direction of a flat plate-shaped work into the same direction and forming a positioning notch for welding at an edge in the longitudinal direction. CONSTITUTION:A nip bending die 24 having a recessed part 24a and a cutting die 25 having a die hole 25a are installed on a die holder 22; a flat plate-shaped work 1 is put on the dies 24 and 25 and is held by two couples of movable nets 27. A root bending punch 35 and a cutting punch 36 are moved down by a punch holder 23 to prebend both edges in the axile direction of the work 1 upward and to concurrently form a notch on at least either edge in the longitudinal direction of the work 1. The prebent parts are bent inside to form a U-shape in the width direction of the work 1 and are finish formed into a cylindrical shape. Then, the cylindrical work is positioned against a welding torch, making the notch a reference point. Butted parts of the work 1 are automatically welded by the welding torch to form a cylindrical tube.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a cylindrical tube that enables automation of the cylindrical tube manufacturing process.

(Prior art) As a conventional method for manufacturing a cylindrical tube, for example, Fig. 5+a
) to (a).

Here, a flat workpiece 1 as shown in FIG. 5(a) is used as a starting material, and when forming both ends of the workpiece 1 in the width direction into a shape as shown in FIG. 5(b), For example, by using a bending die 2 as shown in FIG. 6, the width direction of the workpiece 1, in other words, both end portions of the cylindrical tube in the circumferential direction are pre-bent in the same direction, i.e. , by bending work 1,
The workpiece 3 shown in the figure is brought out.

Here, this bent mold 2 forms a shallow gutter-like recess corresponding to the cross-sectional shape of the workpiece 3 on the upper surface of the die 4, and also forms a cylindrical shape in the width direction and length direction of the workpiece 1. Each fixing nest 5 that contacts the end surface in the axial direction of the tube to position the work 1 at a predetermined position on the die 4 is embedded and fixed, and the lower surface of the punch 6 is
The mold 2 forms a convex surface corresponding to the concave surface of the die 4. The mold 2 forms the workpiece 3 by moving the workpiece 1 to the die 4 attached to the press machine under the action of the fixing nest 5.
After setting as shown in figure (b), punch 6 and die 4
This can be done by making these work together as shown in Figure 6+a) and (b).

Next, here, the workpiece 3 is formed into a U-shape as shown in FIG. 5+1)). For this purpose, for example, a zero bending mold 7 as shown in FIG.
By bending and forming it into a U-shape as shown, the illustrated work 8 is obtained. Here, this 0-bending mold 7 forms a gutter-like recess on the upper surface of the die 9 that fits with the work 3 and positions the work 3 at a predetermined position on the die 9, and also forms a gutter-like recess on the upper surface of the die 9. A U extending in the same direction as the central part
A letter-shaped concave portion is formed, and the lower end of the punch 10 is formed into a protrusion shape corresponding to the U-shaped concave portion of the die 9.
The mold 7 is constructed by forming a ridge on the top of the protrusion to avoid interference with both ends of the workpiece 8.
A zero-bent workpiece 8 is produced in the same manner as the bending die 2.

Furthermore, in the final forming step, the workpiece 8 is formed into a cylindrical workpiece 11 as shown in FIG. 5+d). Here, the finishing mold 12 for such molding is
As shown in FIG. 8, the upper surface of the die 13 and the punch 14
The finishing mold 12 is formed by forming semicircular recesses on the lower surfaces of the molds 12 and 12 in close contact with each other to define a circular hole having a size equal to the outer diameter of the cylindrical tube to be manufactured. Also, by working together with the punch 14 and the die 13, the workpiece 12 is finished formed into a cylindrical shape in the same manner as the bending die 2.
bring about.

Here, in the arc welding process, the abutted end portions of the workpiece 12 are joined by plasma arc welding, for example, as shown in FIG. 5(a), thereby forming the cylindrical tube 15 as the final product. bring. In addition, 15a in the figure shows an arc welding part.

(Problems to be Solved by the Invention) By the way, in the conventional method as described above, in the arc welding process, the butt end portions of the work 11 are
When positioning the workpiece 11 at a predetermined position relative to the welding torch, since the workpiece 11 does not have any means for positioning, the worker manually moves the butt end portion of the workpiece 11 relative to the welding torch. There was a problem in that it required positioning, making it extremely difficult to automate the welding work.

Jin's invention provides a method for manufacturing cylindrical tubes that advantageously solves the problems of the conventional methods.

(Means for Solving the Problems) The present invention includes a first step of pre-bending both widthwise end portions of a flat workpiece to be formed into a cylindrical tube in the same direction; A second step of bending the workpiece that has passed through this second step into a U-shape with the preliminary bending portion facing inward in the width direction, and a third step of final forming the workpiece that has undergone this second step into a cylindrical shape. and a fourth step of joining the abutted end portions of the workpieces that have undergone the third step by arc welding using a welding torch. A notch is formed in at least one end in the length direction, and in the fourth step, the workpiece is positioned relative to the welding torch using the notch as a reference.

(Function) In this method, before the preliminary bending is completed in the first step, or before the first step, a notch is cut in the longitudinal end portion of the workpiece, which is a cylindrical tube. Then, in the fourth step, the cylindrical workpiece is positioned relative to the welding torch using the notch as a reference.In the fourth step, the operator positions the workpiece relative to the welding torch. There is no need for manual positioning, and therefore the fourth step, and by extension the entire cylindrical tube manufacturing process, can be easily automated.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 illustrates an apparatus for carrying out the first step of the method of the present invention, and FIG. 1(a) shows a plan view of a bending and cutting mold for the first step. 1) shows a cross section taken along line 1-1 in FIG. 1+a).

Here, 1 in the figure shows a flat workpiece similar to that described in the conventional example, and 21 bends both end portions of the workpiece 1 in the width direction in the same direction, and 1. A bending and cutting die is shown for forming a notch at at least one end, here both ends, of a workpiece 1 in the length direction.

This bent and cut mold 21 is attached to a die holder 22.
and a punch holder 23, which are fitted onto the upper surface of the gouger holder 22, respectively, at both ends in the longitudinal direction (left and right directions in the figure) of a bending die 24, as is clear from FIG. 1(a). Two cutting dies 25 which are aligned and fixed are provided. Further, here, the longitudinal dimension of the strip bending die 24 is made almost equal to the longitudinal dimension of the workpiece 1, and both ends of the workpiece 1 in the widthwise direction are placed in the center part of the die 24 in the widthwise direction. A shallow gutter-like recess 24a with an upwardly inclined surface corresponding to the surface of the die 24 is formed extending in the longitudinal direction of the recess 24a. By contact,
A rough nest 26 for roughly positioning the work 1 at a predetermined position on the die 24 is embedded and fixed.

On the other hand, each cutting die 25 is formed with, for example, a pentagonal die hole 25a, with the V-shaped tops of the respective gouge holes 25a facing each other, and the workpiece placed at a predetermined position on the die 24. 1, so as to overlap each other at both end portions in the length direction.

Here, two pairs of movable nests 27 are also provided on the die 24, spaced apart from each other in the length direction thereof and facing each other. These multiple pairs of movable nests 27 are each fixed to the tips of two arms 28 arranged at the ends of the die 24, and these arms 28 are each fixed to a guide 29 fixed to the upper surface of the gooey holder 22. is rotatably supported via a pin 30. Here, the rear ends of the two arms 28 are slidably supported by a guide 29 via a long hole formed therein and a bottle 3 inserted through the long hole.
The slider 32 is connected to, for example, a piston rod 34a of an air cylinder 34 fixed to the gouey holder 22 via a bracket 33.

With this configuration, multiple pairs of movable nests 27
are separated from each other by the operation of the air cylinder 34 in the advancing direction of the piston rod 34a, and can be brought closer to each other by the operation of the air cylinder 34 in the retracting direction of the piston rod 34a. Based on the backward movement of the piston rod 34a, the pair of movable nests 27 sandwich the workpiece 1 from the width direction thereof, and even if the workpiece width is reduced due to preliminary bending of the workpiece, the workpiece 1 can be held in the die. 24 can be reliably held in place.

On the other hand, a corner bending punch 35 and two cutting punches 36 are fixed to the lower surface of the punch holder 23, respectively. Here, the edge bending punch 35 has a convex portion corresponding to the concave portion 24a of the die 24 on its lower surface, and
At its four corners, there are not-shown barbed portions to avoid interference with the movable nest 27 and the arm 28. Note that the cutting punch 36 can be fitted into the gouging hole 25a of the die 25 with a predetermined clearance.

Here, four fixed stock wipers 37 are further attached to the lower surface of the punch holder 23. Each of these stock wipers 37 has an inwardly sloping surface at its tip, and when the punch holder 23 is lowered, the stock wiper 37 corrects the longitudinal position of the workpiece 1 with respect to the die 24 and removes the workpiece. 1 in a predetermined position.

The first step using the bending and cutting mold 21 configured as described above can be performed as follows.

First, the punch holder 23 is attached to a ram (not shown) of a press machine, and the guide holder 22 is attached to a bolster (not shown) of the press machine, and the mold is opened by the rise of the ram, and the flat workpiece 1 to be formed is placed in front of the die holder 22. The workpiece is cured by a workpiece guide 38 attached to the side, fed onto the die 24, and brought into contact with the roughnest 26.

Next, by operating the air cylinder 34, the work 1 is held between the movable nests 27, and the work 1 is
Position in the width direction.

Then, the punch holder 23 is lowered by the subsequent lowering of the ram, and as a result, after the stock wiper 37 has positioned the work 1 in its length direction, the punch 36
V-shaped cutting of both ends of the workpiece 20 in the length direction under the cooperation of the punch 35 and the die 25, and the punch 35 and the die 2
Preliminary bending of both ends of the work l in the width direction is performed sequentially in cooperation with the workpiece 4.

According to this first step, both ends of the work 1 in the width direction are bent in the same direction, and a V-shaped notch is formed in both ends of the work 1 in the length direction. Particularly here, the piston rod 34a of the air cylinder 34 is continuously energized in the backward direction until the cutting and bending are completed, so that the workpiece can be moved to a predetermined position. The above-mentioned cutting and bending can be performed with high positional accuracy by effectively preventing deviation from the position.

In addition, here, the second process includes the workpiece 2 that has passed through the first process.
0 is bent and formed into a U-shape in the width direction using the U-shaped bending mold 7 illustrated in FIG. The finished workpiece is transferred to the finishing mold 11 in the third step as shown in FIG.
This is also finished formed into a cylindrical shape in the same way as in the conventional example, resulting in a cylindrical workpiece 39 shown in FIG.

Figure 2 (al) is a front view illustrating an arc welding device that can automatically join the butt end portions of workpieces 39 by plasma arc welding, and Figure 2 (f) and (C).
) are the b-b arrow view and c of the device shown in Fig. 2 fal.
-c arrow view, this arc welding device includes a welding device main body 40, a workpiece loading ramp 41, a workpiece circumferential position detection device 42, a workpiece transport device 43, a workpiece unloading ramp 44, etc. Consists of peripheral equipment.

The welding apparatus main body 40 here includes a table 4 which is inclined in a plane orthogonal to the conveyance path of the workpiece 39 on a base 45.
6, and on this table 46, a work positioning device 47 that clamps the work 39 in the axial direction and positions the work 39 in the circumferential direction, and a clamp device that clamps the work 39 from the side thereof. , a welding torch 49 that performs plasma arc welding on the butt end portions of the workpiece 39, and a welding torch 49 that connects the welding torch 49 to the workpiece 39.
A torch moving device 50 is provided to move the torch in the axial direction of the torch.

Note that the workpiece positioning device 47 here is, for example,
As shown in FIG. 2fb), a fixed member 47a is fixed on a clamp stand 48a provided on a table 46, and a movable member 47b is supported so as to be movable forward and backward relative to the fixed member 47a. 47b to the clamp stand 48
While connected to the piston rod of an air cylinder 47c fixed to the end of the workpiece 39, the fixed member 47a and the movable member 47b are fitted into V-shaped notches formed at both longitudinal ends of the workpiece 39. It can be constructed by providing the V-shaped protrusions that fit into each other so as to face each other.

Further, the clamp device 48 includes, for example, a clamp stand 48a.
At the top, a pair of clamp claws 48b that can move forward and backward relative to each other.

48b, an air cylinder 48c is fixed in a downward direction within the clamp base 48a, and the piston rod of the air cylinder 48c is connected to the clamp claws 48b, 48b via a link mechanism 48d. be able to.

Further, the torch moving device 50 is provided with two guides 50a that extend in an inclined direction parallel to the clamp base 48a, and a slider 50b supported movably along the guides 50a, 50a is moved by a motor 50c. It can be configured such that it can be driven by a ball screw 50d coupled to the output shaft of.

Further, the workpiece circumferential position detection device 42 has two rollers 42c, 42c driven by a motor 42b pivoted in parallel to each other on a tilting table 42a, and
The tilting table 42a can be tilted by an air cylinder 42d between a horizontal position and a position tilted parallel to the clamping table 48a, and further between rollers 42C+42c,
A proximity switch (not shown) capable of detecting the notch of the workpiece 39 placed thereon is provided. and,
The workpiece transfer device 43 moves a moving base 43c onto a frame 43b supported by four pillars 43a, and transfers the workpiece 3 to the frame 43b.
An air cylinder 43d is provided to support the movable base 43c so that it can move forward and backward in the transfer direction of the moving base 43c, and to drive the movable base 43c to move forward and backward. An air cylinder 43f that moves up and down is provided, and two clamp devices 43h that grip and release the wire 39 or the cylindrical tube 51 by the operation of the air cylinder 43g are mounted on the lift base 43e and are tilted parallel to the table 46. It is configured by providing

Here, these clamp devices 43h, 43h are placed in parallel with the clamp table 48a of the circumferential position detection device 42 of the workpiece when the movable base 43c fc is in the retracted position and the elevating base 43e is in the lowering limit position. The work 39 on the two inclined rollers 42c and 42c and the cylindrical tube 51 sandwiched between the fixed member 47a and the movable member 47b of the work positioning device 47 and subjected to arc welding are respectively gripped. be able to. Also,
Thereafter, the movable base 43c is moved to the advance limit position with the lift base 43e at the upper limit position, and when the lift base 43e is further lowered to the lower limit position, the rollers 42
c, the workpiece 39 gripped on 42c is fixed to the fixing member 47a.
At the same time, the cylindrical tube 51 held between these members 47a and 47h is placed at a predetermined position between the movable member 47b and the movable member 47b. Product receiver 44a at the upper limit position
It can be placed on top.

The product receiver 44a is raised and lowered by an air cylinder 44b, and the cylindrical tube 51 can be transferred from the clamp device 143h onto the ramp 44c.

The fourth step using such an arc welding device can be performed as follows.

Here, first, the ramp 41 of the work loading ramp 41 is
The workpiece 39, which has been finished and formed into a cylindrical shape through the third step described above, is placed on the end of the section a remote from the circumferential position detection device 42, and the workpiece 39 is transferred by gravity to the ramp 4.
It is placed on a workpiece receiver 41c that is provided at the other end of 1a and is raised and lowered by an air cylinder 41b. After that,
By raising the workpiece receiver 41c, the workpiece 39 is transferred to the roller 42c of the workpiece circumferential position detection device 42 via the ramp.

42c.

Next, the workpiece 39 is rotated by rotating the rollers 42c, 42c, and the roller 42c is rotated based on the detection of the notch in the workpiece 39 by the proximity switch.

By stopping the 42 cm appropriately, the work 39 is positioned with the butt end portion of the work 39 facing upward, and the tilting table 42a is tilted to move the work 39.
is in an inclined position parallel to the clamp table 48a.

This work 39 is then transferred to the work transport device 43 □
The workpiece is then transferred to between the fixed member 47a and the movable member 47b of the workpiece positioning device W47.

Here, this work 39 is further attached to both members 47a.

By fitting the V-shaped protrusions of these two members into the V-shaped notch of the workpiece 39 by holding them between 47h and 47h, the circumferential position of the workpiece 39 can be adjusted to a predetermined position with the abutting end facing toward the welding torch 49. After positioning the workpiece with high precision and raising the clamping device 43h of the workpiece transfer device 43, the clamping device 48 is activated, and the air cylinder 48c
The clamp claws 4 are moved toward each other by
8b and 48b grip and fix the positioned workpiece 39. Here, both of these clamp claws 48
There is an upward gap between 48h and 48h that allows the welding torch 49 to perform the welding operation.

Here, the welding torch 49 is moved by a torch moving device 50.
While moving the workpiece 39 in the axial direction, the welding torch 49 applies plasma arc welding to the abutting end portions of the workpiece 39 to form a cylindrical tube 51.

The cylindrical tube 51 that has been arc-welded in this manner is further placed on the product receiver 44a by the work transfer device 43, and the receiver is transferred from the product receiver 44a to the ramp 44c.

According to the method described above, in the first step, a V-shaped notch is formed in the workpiece to be made into a cylindrical tube with high positional accuracy,
In the subsequent fourth step, the V-shaped protrusions of the fixed member and the movable member are fitted into this V-shaped notch, and the workpiece is positioned relative to the welding torch, so the operator manually This eliminates the need for workpiece positioning work at all, making it possible to automate the fourth process and even the entire welding process, and in that process, positioning the workpiece relative to the welding torch with high precision, making it possible to A cylindrical tube with a quality pedestal joint can be produced.

The cylindrical tube 51 manufactured by this method has V-shaped notches 51a at both ends as shown in FIG. By fitting it to another part and welding it, the notch can be used without any problems, as in the case of using it.

In addition, in the above-mentioned example, in the first step, the formation of a notch in the workpiece and preliminary bending are performed sequentially using a bending and cutting die, but for example, in the first step, A notch may be formed in advance, and only preliminary bending may be performed in the first step using the notch as a reference. In such a case, a short bending mold using only a fixed nest may also be used.
Preliminary bending can be performed with even higher positioning accuracy.

(Effects of the Invention) Thus, according to the method for manufacturing a cylindrical tube of the present invention, there is no need for manual positioning of the workpiece by the operator in the fourth step, that is, the welding step, so it is possible to automate the welding step. At the same time, a cylindrical tube with high quality welds can be obtained.

[Brief explanation of drawings]

Figure 1 (al is a plan view excluding the upper mold illustrating the bending and cutting mold used in the first step of the method of the present invention; Figure 1 (bl is the mold shown in Figure 1 (al); 2 (al is a front view illustrating the arc welding device used in the fourth step of the present invention, FIG. 2(b), (el is FIG. Figure 3 is a perspective view illustrating a cylindrical tube manufactured using this method; Figure 4 is a cylindrical tube shown in Figure 3; Fig. 5 is a process diagram showing a conventional cylindrical pipe manufacturing method; Fig. 6 (a) shows a conventional Φ bending mold that produces the workpiece shown in Fig. 6 (bl is a plan view excluding the upper mold of the mold shown in FIG. 6 Tal, FIG. 6 (C1 is a sectional view of the mold shown in FIG. 6 (al),
The figure is a side view showing a conventional U-bending die that produces the workpiece shown in Fig. 5[e], and Fig. 8 is a side view showing a conventional finishing die that produces the workpiece shown in Fig. 5+dl. 1.20.39 Work 21 Bending and cutting mold 24 Bending die 25 Cutting goo 27 Movable nest 40 Welding device main body 41・・・
- Inclined table for carrying in the workpiece 42... Circumferential position detection device 43... Workpiece conveyance device 44... Inclined table for carrying out the workpiece 47... Workpiece positioning device 47a... Fixed member 47b... Movable member 4
8... Clamp device 49... Welding torch 50
...Torch moving device 51...Cylindrical tube patent applicant Nissan Motor Co., Ltd. (a) Fig. 7 Fig. 6 (b) (C) Fig. 8

Claims (1)

[Claims] 1. A first step of pre-bending both widthwise end portions of a flat work in the same direction, and pre-bending the work after the first step in the width direction. The second step is to bend the molded part inward into a U-shape, and the third step is to finish form the workpiece after the second step into a cylindrical shape.
and a fourth step of joining the abutted end portions of the workpieces that have undergone the third step with a welding torch, in which the length of the workpiece is A method for manufacturing a cylindrical tube, characterized in that a notch is formed in at least one end in the transverse direction, and in the fourth step, the workpiece is positioned with respect to a welding torch using the notch as a reference.