JPH0450974Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the production of conical tubes, and in particular to an apparatus for producing conical tubes using three rollers.

[Conventional technology]

Conventional methods for manufacturing conical tubes include press molding for large quantities, and manual processing using a hammer or the like for small quantities. However, the press molding method requires a press die, a press machine, etc., and is not simple, and the manual method requires skill. In addition, a device for manufacturing right cylinders using three rollers is known as a device for bending sheet metal relatively easily.Furthermore, in order to obtain a conical tube, the sheet material is cut into fan shapes. It is also known what should be done.
Therefore, in order to obtain a conical tube relatively easily, it is conceivable to apply a fan-shaped material to the right cylindrical cylinder manufacturing device using the three rollers mentioned above. It is not possible to manufacture the desired conical tube just by doing this.

[The problem that the idea aims to solve]

The present invention was devised in view of the above-mentioned problems of the prior art, and its purpose is to eliminate the need for complicated and expensive press machines and manual processing that requires skill. The object of the present invention is to manufacture a conical tube with the same ease as manufacturing a right cylinder using this roller.

[Means to solve the problem]

The inventors of the present invention investigated the reason why a conical tube could not be formed by simply applying a fan-shaped material to a three-roller device. It was discovered that it was sufficient to prevent the holding roller from moving in the axial direction of the holding roller, and based on this discovery, the present invention was completed.

The configuration of the present invention is to manufacture a conical tube in which a fan-shaped material is inserted between a pair of rotatable holding rollers, moved in the rotational direction of the rollers, and then bent by a third bending roller to form a conical tube. The apparatus includes a jig including a portion inserted between the pair of pinching rollers and a curved portion abutting an inner circular arc portion of the material, the jig being inserted between the pair of pinching rollers. Further, the contact point between the curved portion of the jig and the inner circular arc portion of the material is located on an imaginary plane passing through both axes of the pair of nipping rollers.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 indicates a material for making a conical tube, which is formed by cutting out a substantially fan-shaped plate material as shown in the figure, and the dimensions of each part are determined from a well-known simple geometry.

In FIG. 2, reference numeral 2 denotes a conventionally known right cylinder manufacturing apparatus using three rollers, 2a, 2b,
It has three rollers of 2c, of which 2
Reference numerals a and 2b are a pair of clamping rollers that rotate while holding the material (plate material) and feed the material to the back, and 2c is a bending roller that bends the material by adjusting its height. It functions to adjust the amount of bending. In order to form a right cylinder using this device, the plate material is passed between the nipping rollers 2a and 2b and bent upward by the rear bending roller 2c, and this action is repeated several times to adjust the height of the bending roller 2c each time. The plate material is formed into a cylindrical shape by gradually increasing the height and decreasing the radius of curvature of the plate material, but since the structure and operation of this device itself are well known, a detailed explanation will be omitted. Reference numeral 3 denotes a jig according to the present invention, which is clamped and attached between two pinching rollers 2a and 2b by a mounting portion 3a.
The attachment part 3a is formed in the shape of a leaf spring and is configured to be able to hold the roller 2b, so that the jig 3 and the roller 2 can be held together.
b is rotatably attached. The positioning part 3b is tightly fixed to one end of the jig 3, and the other end is in contact with one of the supporting base parts (not shown) of the three rollers, so the jig 3 is connected to the second
Movement to the left in the figure can be prevented. FIG. 3 shows a conical tube manufactured using the apparatus shown in FIG.

To explain the structure of the jig 3 in the present invention in more detail with reference to FIG. 4, the jig 3 has quarter-circular notches 31 and 32 formed adjacent to each other at a distance l on its back surface. A main body part with a curved part 33 formed at the end in the longitudinal direction, a semicircular plate spring part 3a tightly fixed to this with a machine screw, and the curved part 33 of the main body using screws and nuts. The positioning portion 3b is tightly fixed to the opposite end. The cutout portions 31, 32
are the two pinching rollers 2a to which this is attached,
It is formed with a radius substantially equal to the radius of the rollers 2b, and its tip (the tip on the back surface) is arranged at a position that is substantially in contact with a line O connecting the centers of the rollers 2a and 2b. [See FIG. 4C] Also, the notch 31,
32 are disposed apart by a distance l, and the distance l is formed to be slightly smaller than the thickness of the material 1 of the conical tube to be obtained.

The curved portion 33 at the end of the main body is formed with a radius smaller than the radius of the inner arc 1a of the material 1;
The radius of this curved portion 33 does not require a strict dimension, as long as it is a curve that can smoothly slide into contact with the inner arc 1a of the material 1 in the bending process described later.

Next, the operation of the apparatus having the above configuration will be explained.

To explain the operation of the conventionally known three-roller device and the device according to the present invention in comparison, Fig. 5a shows the case where a fan-shaped material 1 cut into a plate for a conical tube is bent by the conventionally well-known three-roller device. However, since this three-roller device originally forms a right cylinder, the pinching rollers 2a, 2
The material 1 held between the rollers 2a and 2b moves upward in the figure by the rotation of the rollers 2a and 2b, but the direction of movement is perpendicular to the axis O of the rollers 2a and 2b, so this step Later bending roller 2c
Even if it is bent, it will not be formed into a conical shape, but only a shape close to a right cylinder.

The present invention was developed by observing and studying this point in detail, and the axis O of the pinching rollers 2a and 2b was
K
Focusing on this point K and observing it while rotating the rollers 2a and 2b, it was found that K moves to the left in the figure with rotation, reaches K', and then moves to the left one after another. .

Focusing on this, the present inventors thought that a conical shape could be obtained by preventing the movement of the K point, and used a roller 2 as shown in FIG.
When we experimented by placing and fixing the round bar 4 just before points a and 2b, we succeeded in obtaining a substantially conical shape, but due to the distance between the round bar 4 and point K, As the material 1 rotated around the round rod 4, the K point also moved, and the resulting conical shape was twisted. Therefore, the inventors made further improvements and completed the jig of the present invention, which abuts the inner arc 1a of the material 1 at the position of point K, as shown in FIG. 5c.

As can be seen from the above description, a desired conical tube can be obtained by using the jig 3 according to the present invention.

In addition, a bending roller 2c that applies bending force to the material 1
A conical shape can be obtained more easily by tilting the rollers 2a and 2b with respect to the holding rollers 2a and 2b.
The conventionally known three-roller device usually has a bending roller 2c.
This can also be done easily since it has a function to tilt the screen.

Further, the jig of the present invention is not limited to the above-mentioned embodiment, but may have any shape as long as it does not move the point K in FIG. 5.

[Effect of idea]

Since the present invention has the above configuration,
During the forming process, the contact point between the inner arc of the fan-shaped material passing between the pair of clamping rollers and the imaginary plane passing through both axes of the pair of clamping rollers does not move in the axial direction of the clamping rollers. Therefore, a conical tube with an accurate shape can be obtained.
Therefore, it is possible to manufacture a conical tube with the same ease as manufacturing a right cylinder using three rollers, which is conventionally well known, without using a complicated and expensive press machine, or without manual processing that requires skill. This has the effect of making it possible to

[Brief explanation of the drawing]

Fig. 1 is a plan view of the conical tube material used in the present invention, Fig. 2 is a perspective view of an embodiment of the device of the present invention, partially shown in cross section, and Fig. 3 is a conical pipe material obtained by the present invention. 4 shows a jig in the apparatus shown in FIG. 2, a is a top view thereof, b is a rear view thereof, and c is a diagram of FIG. 4 a. A side sectional view taken along the line A-A, and FIG. 5 are explanatory diagrams showing the manufacturing process of the conical tube, where a is a case where a conventionally known device is used, b is a case where an experimental device is used, and c is a case where the present invention is used. The following is a case in which the following examples are used. 1...Material, 1a...Inner arc, 2...Three roll device, 2a, 2b...Pinching roller, 2c...
Bending roller, 3... Jig, 3a... Mounting part, 3b
...Positioning section.

Claims (1)

[Scope of Claim for Utility Model Registration] After inserting a fan-shaped material between a pair of rotatable holding rollers and moving it in the rotational direction of the rollers, a third
In a conical tube manufacturing apparatus that forms a conical tube by bending the material with a bending roller, the jig includes a portion inserted between the pair of pinching rollers and a curved portion that abuts an inner circular arc portion of the material. the jig is inserted between the pair of pinching rollers, and the point of contact between the curved part of the jig and the inner arcuate part of the material passes through both axes of the pair of pinching rollers. A conical tube manufacturing device characterized in that the conical tube is positioned on a virtual plane.