JPH02235506A - Molding method of conical or taper material for metal tube and apparatus - Google Patents

Abstract

PURPOSE: To obtain uniform products without necessitating use of seamless tubes as a stating material by drawing a tube stock through a working cross section comprising a die with a grip tongue during rolls are rotated and making them rotate. CONSTITUTION: A metallic tube is inserted into the max. cross-sectional region of the opposed rolls 2 and fixed in a grip tongue 6. When the rolls 2 are rotated, simultaneously drawing action is attendantly caused and the metallic tube is formed into a conical body. Thus, in the case of multistage forming, to obtain extruded products as round and as uniform as possible, the grip tongue is rotated between individual forming stages. Drawing operation during the rolls 2 are rotated is executed by laterally moving a carrage 12 for carrying the rolls 2 in the direction receding from the grip tongue which is rotatable but fixed by operation of a driving device 13 for drawing. By changing the laterally moving speed of the carrage 12 and/or the rotational speed of the rolls 2, the taper angle of a finished product is adjusted, as necessary.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method and apparatus for forming a metal tube into a conical or tapered body. A pair of rolls having a groove with a cross-sectional shape corresponding to half of the cross-sectional shape and tapered in the circumferential direction are engaged with the outer surface of the pipe material and rolled. It relates to a method for forming a tube into a conical or tapered body, and also to an apparatus for carrying out this method.

[Problems to be Solved by the Prior Art and the Invention J For example, a metal tube with a circular cross section is formed into a conical body while simultaneously being stretched, especially for use in masts, light poles, flagpoles, etc. .

In order to achieve a uniform taper with a cross section as circular as possible, it is necessary with the known methods and devices to process exclusively metallic seamless tubes. The production of this type of cone from a seamless tube is usually carried out by rolling, whereby the rolls serving as forming tools are used to control the length of the finished cone after deformation of the seamless tube. It has a corresponding circumference. In the case of this known method and the equipment necessary for its implementation, in addition to the substantial increase in the cost of the product due to the necessity of using seamless pipes as starting material, each The disadvantage is that the forming rolls used in this case are only suitable for finished cones of a certain length. As a result, for each finished cone of the required length, different sets of rolls have to be used, and this not only requires a considerable outlay in terms of cost, but also the number of forming rolls. Since a considerable amount of time is required for replacement, the operation method requires a large amount of time.

Forging is also known as another method for manufacturing conical bodies from metal tubes with a circular cross section. However, this manufacturing method requires relatively high impact forces and relatively complex and therefore expensive equipment.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the method and apparatus for forming metal tubes into conical or tapered bodies, so that the starting materials for forming no longer need to be limited to seamless tubes. , and in addition, regardless of whether the tube stock to be manufactured has a circular or polygonal cross-section, it has a uniform cross-sectional shape and has different lengths and different degrees of taper. The object is to facilitate the use of the same tool for producing conical or tapered bodies.

[Means for Solving the Problems] According to the present invention, in order to solve the above-mentioned problems, each roll has a groove on its processing surface with a cross-sectional shape corresponding to half the cross-sectional shape of the pipe material, and a circumferential groove. processing by rolling a pair of rolls having grooves tapered in the direction into engagement with the outer surface of the tube stock, wherein:
There is provided a method for forming a metal tube into a conical body, characterized in that the tube stock is drawn by grip tongs through a working cross section constituting a die while the rolls are rotating, and the tube stock is rotated by the grip tongs. Ru.

Further, according to the present invention, each roll has a groove on its surface that engages with the material, the groove having a cross-sectional shape corresponding to half of the cross-sectional shape of the material and tapered in the circumferential direction of the roll. A pair of rotationally driven rolls and a grip tong for holding the material, the grip tong being mounted on a rotating shaft aligned with the longitudinal force axis of the material, and a rotation drive for the grip tong. A device is provided;
A device for carrying out the method is provided, characterized in that a device is provided for generating a relative movement between the roll and the material, and the speed of the device and/or of the drive of the roll is variable. be done.

[Operating effects and modes of the invention]

In the method according to the invention, the drawing operation of the tube stock through the die is combined with a simultaneous rolling operation,
It is clear that the material can also be rotated about its longitudinal axis. Such an operation results in a particularly homogeneous product.

In a preferred embodiment of the invention, the taper angle formed in the product can be adjusted by varying the withdrawal speed of the grip tongs and/or by varying the rotational speed of the rolls.

In this way, the same set of rolls can be used to manufacture a wide range of products, while the simultaneous rotation of the stock during drawing ensures that the starting material is a seamless tube or has no seams. Regardless of which tubes it has, it is guaranteed to produce a product that is as round and uniform as possible.

The material has a relatively small taper angle and a medium length, since the deformation of the material can usually only be carried out in one continuous operation and at the same time an optimally finished product is obtained. In some cases, the processing is carried out preferentially in several forming stages, so that the blank is rotated between the individual forming stages by grip tongs.

The rolls are also rotated in several discrete stages depending on the stages of the various forming operations, so that the minimum diameter between the grooves is not reached until the final stage.

A further particularly important feature of the method according to the invention is that the starting material can be in the form of a blank with a circular or polygonal cross section.

In a preferred embodiment of the device according to the invention, the device for generating the relative movement consists of a slider that moves transversely in the longitudinal direction of the material, to which gripping tongs are attached.

In one variant according to the invention, the device for generating the relative movement consists of a carriage that moves transversely in the longitudinal direction of the material, and a roll is mounted on the carriage.

In particular, it is preferred to provide a positive transmission pull-out drive mounting for the slider. This is because it is ideally suited for the operation of drawing the tube through the rolls that make up the die. In a preferred embodiment, this can in particular be a chain drive. However, a rack and binion drive can also be used instead.

In particular, in a further development of the invention, the roll can be driven by a variable speed electric motor with a gearing.

It is particularly advantageous to mount the rotational drive of the grip tongs together with the grip tongs on the slider. It is likewise advantageous to mount the drive of the rollers on the carriage.

It is further advantageous if the pull-off drive for the slide or carriage is infinitely variable in order to allow maximum control of the relative movement between the blank and the roll.

In a preferred embodiment of the invention, the grooves of the roll have a semicircular cross section. In this regard, it would be advantageous if the grip tongs could be rotated steplessly.

In order to process materials with a polygonal cross-section, the grooves of the variant have a polygonal cross-section. In this connection, it is advantageous if the rotation of the grip tongs takes place in discrete individual increments determined by the angular relationship of the polygonal cross section of the groove.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

The device according to the invention, designated as a whole by the reference numeral 1, comprises a pair of rolls 2, as its main components, as shown in the accompanying drawings.
3 (see Figure 3). The working surfaces 4 of the rolls 2, 3 which engage the blanks (not shown) each have a groove 5 of semi-circular cross-section extending around the circumference of the rolls 2, 3. The groove 5 is tapered in the circumferential direction of the rolls 2, 3, as shown in the partially cutaway view in FIG. 3, so that when the rolls 2.3 rotate relative to each other, The virtual cylindrical surface formed by the cross sections of the opposing grooves changes into a conical shape as the groove rotates.

According to the present invention shown in FIG. In the case of an embodiment of the device, the frame 20 of the device 1 is provided with gripping tongs 6 for holding the blank (not shown).

The gripping tongs 6 are mounted on a rotating shaft 7 aligned with the longitudinal axis of the material, and the gripping tongs have a rotational drive (not shown, abstracted by arrow 8) as indicated by arrow 8 in FIG. is being worn.

When forming the tube blank into a conical body, the tube used as blank is drawn during the rotation of the rolls 2, 3 through a deforming section formed between the rolls, which operate in a manner similar to a gouer.

For this pulling operation, in the embodiment shown in FIG. 1, a device (indicated overall by 9) is provided which makes it possible to generate a relative movement between the roll 2.3 and the material. .

In the illustrated embodiment, the device 9 is in the form of a carriage 12 on which the rolls 2, 3 are mounted via their shafts 21,22. The carriage 12 is also equipped with a mouth drive device, generally designated by the reference numeral 10.

This roll drive device 10 is preferably a variable speed electric motor 14 equipped with a gear device 15 that can change the rotational speed of the roll infinitely.

The carriage 12 is moved relative to the grip tongs 6 by means of a withdrawal drive 13 . The extraction drive 13 is preferably of the type of positive transmission, for example a chain drive or a rack and pinion drive.

In the embodiment of FIG. 2, in which identical components or components serving the same function are designated by the same reference numerals, a pair of rolls 2.3 with a roll drive 10 is identical to that shown in FIG. In contrast to the embodiments described above, it is fixed to a fixed pedestal 16 forming part of the frame 20 of the device 1.

On the other hand, the grip tongs 6 are attached to the slider 11 together with a rotary drive device (abstracted by an arrow 8). The slider 11 moves on the guide path 19 when actuated by the extraction drive 13.

Also shown in FIG. 3 are a pair of spur gears 23,24. The rolls 2, 3 are rotated in mutually opposite directions by spur gears 23,24.

In order to form a metal tube into a cone using the device according to the invention, the metal tube is inserted into the largest cross-sectional area between the opposing rolls 2, 3 and fixed in the gripping tongs 6. When the rolls 2.3 rotate, a drawing action takes place at the same time, forming the metal tube into a cone, so that in the case of multistage forming, a drawing product as round and uniform as possible is obtained. The grip tongs are then rotated between the individual forming stages.

In order to ensure that a high-quality product is obtained, in the case of long workpieces with large taper angles, the forming operation is divided into several steps in which the rolls are rotated by a fraction of their total circumference during each forming step. The grip tongs, and thus the partially formed blank, are rotated between the individual forming steps in order to obtain as uniform a cross-sectional shape as possible over the entire length of the finished product. The opening formed by the groove 5 therefore does not reach its minimum diameter until the final molding stage.

The extraction operation during rotation of the rolls 2, 3 is carried out in such a way that the carriage 12 carrying the rolls 2.3 can be rotated by actuation of the extraction drive 13, as in the embodiment shown in FIG. is mounted on the slider 11 by being moved laterally away from the grip tongs 6 to which it is fixed, or, as in the embodiment shown in FIG. The rotationally driven grip tongs 6 are attached to the fixed roll 2.3.
This is done by horizontally moving away from the object.

In either case, the slider 11 or the carriage 12
By changing the lateral movement speed and/or the rotational speed of the rolls 2, 3, the taper angle of the finished product can be adjusted as required. The rotational speed of the rolls, which together with the drawing speed determines the taper angle of the product, is varied by a preferably electronic speed control controlling the motor 14.

In any case, a large number of different cones with different taper angles can be produced without changing the tools, ie the rolls 2, 3. Moreover, due to the rotational movement generated by the gripping tongs, there is no need to use seamless tubes as starting material and a very uniform product is produced.

It is clear that materials with any cross-section can be processed by suitably designing the grooves 5 of the rolls 2, 3.

In the case of a circular material, the groove 5 has a semicircular cross section, as in the previously described embodiment. In this case, the grip tongs 6 can be rotated steplessly, that is, continuously, since there is no limit to the angle. When processing a material having a polygonal cross section, the groove 5 has a cross section corresponding to half of the polygonal cross section of the material. In this case, the grip tongs 6 can be rotated in discrete increments corresponding to the angular relationship of the materials.

All the features and advantages of the invention described and illustrated in the foregoing description, claims and accompanying drawings, including details of design and arrangement, are essential to the invention both individually and in any combination. It can be considered as something similar.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a device according to a first embodiment of the present invention, FIG. 2 is a side view corresponding to FIG. 1 showing a second embodiment of the present invention, and FIG. FIG. 3 is a partially cutaway view of a forming roll. 2.3 is a roll, 4 is a machined surface, 5 is a groove, 6 is a grip tong, 7 is a rotating shaft, 9 is a device that generates relative motion,]
0 is a roll drive device, 11 is a slider, 12 is a carriage, 13 is a pulling drive device, 14 is a variable speed electric motor, 15
is a gear device.

Claims (10)

[Claims] (1) A pair of rolls, each roll having a groove on its processed surface with a cross-sectional shape corresponding to half of the cross-sectional shape of the tube material and tapered in the circumferential direction, are placed on the outer surface of the tube material. The tube stock is worked by rolling in engagement with the rolls, in which the tube stock is pulled out by grip tongs through the working cross section constituting the die while the rolls rotate, and the tube stock is rotated by the grip tongs. A method for forming a metal tube into a conical body, characterized by: (2) Change the grip tong pull-out speed, and/
or the taper angle formed on the product can be adjusted by changing the rotational speed of the rolls, the forming process is carried out in several deformation stages, the material is rotated between the deformation stages by grip tongs, 2. The method of claim 1, wherein the starting material has a circular or polygonal cross section. (3) A pair of rotations in which each roll has a groove on its surface that engages with the material, the groove having a cross-sectional shape corresponding to half of the cross-sectional shape of the material and tapered in the circumferential direction of the roll. comprising a driven roll and gripping tongs for holding the material, the gripping tongs (6) being mounted on a rotating shaft (7) aligned with the longitudinal axis of the material;
A rotary drive (8) for the gripping tongs (6) is provided, a device (9) is provided for generating a relative movement between the rolls, (2, 3) and the blank, and said device ( 9
) and/or the drive device (13,
3. Apparatus for carrying out the method according to claim 1 or 2, characterized in that the speed of step 10) is variable. (4) The device (9) for generating relative motion comprises a slider (11) that moves laterally in the longitudinal direction of the material, and a grip tong (6) is mounted on the slider (11). Device. (5) The device (9) for generating the relative movement comprises a carriage (12) that moves laterally in the longitudinal direction of the material, and the rolls (2, 3) are mounted on the carriage (12). equipment. (6) A reliably transmitted pull-out drive (13) is provided for the slider (11) and/or the carriage (12), a rotary drive (8) is mounted on the slider (11), and a drive ( 10, 14, 15) is mounted on the carriage (12). 7. Apparatus according to claim 6, wherein the extraction drive (13) is of the type of a chain drive or a rack and pinion drive. 8. Device according to claim 3, characterized in that the drive (10) of the rolls (2, 3) is of the type of a variable speed electric motor (14) with a gearing (15). 9. A device according to claim 3, wherein the groove (5) has a semicircular cross section and the grip tongs (6) can be rotated infinitely. (10) The groove (5) has a polygonal cross section, and the grip tongue (6) is rotationally driven in discrete increments determined by the angular relationship of the polygonal cross section of the groove (5). 9. The device according to any one of 3 to 8.