JPH0422890Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an inner bead cutting device for electric resistance welded steel pipes.

[Conventional technology]

ERW steel pipes are made by forming a steel plate into a tubular shape while continuously moving it forward, heating the ends of the tubular steel plate with a high-frequency welding machine, and heating the ends of the tubular steel plate until it becomes red-hot, then pressing the opposing ends together with a squeeze roll. Manufactured.

At this stage, the beads formed on the inside and outside of the abutting surfaces are removed by a bead cutting device. Whether or not this cutting is done well is extremely important in determining the quality of the product.

Therefore, bead cutting equipment must be adjusted to achieve good cutting conditions.

Conventionally, as shown in FIG. 6, as an inner bead cutting device for an ERW steel pipe, a cutting device main body 1 is provided with a
Attach two fixed upper rollers 10 and 11 spaced apart from each other in the longitudinal direction of the steel pipe and a cutting tool 4,
The base end of a lower roller support arm 12 is pivotally attached to the cutting device main body 1 by a pin 13, and the lower roller 5 is attached to the tip of the lower roller support arm 12. The piston rod 15 of the pressing hydraulic cylinder 14 is connected to the lower roller support arm 12.
The lower roller supporting arm 12 is rotated by engaging with the middle upper part of the steel pipe 8 and extending the lower roller pressing hydraulic cylinder 14, so that the lower roller 5 can be pressed against the inner surface of the steel pipe 8. Koro 10,1
1 and the lower roller 5 form a triangle, and the cutting device main body 1
The structure is such that it can be held in place.

The cutting device main body 1 is installed 1 to 2 m downstream from the welding point, and a support device 16 is installed at the expanded place before steel pipe forming, and the cutting device main body 1 is connected to the support device 16 by a rod 17, Cutting device body 1
The structure is such that it can be held at a fixed position in the tube axis direction. Normally, the rod 17 has a length of 8 m and penetrates deep into the pipe from the supported location, so that the cutting device main body 1 is in a position that cannot be directly touched. Thus, by moving the steel pipe 8, cutting can be performed according to the amount of overlap between the cutting tool and the bead 18, which is determined by the relative relationship between the positions of the fixed upper rollers 10 and 11 and the cutting tool 4.

In addition, in Fig. 6, 19 is a squeeze roll,
20 is a welding machine.

However, when cutting the inner bead of an ERW steel pipe using the conventional inner bead cutting device, cutting is performed under initial conditions in order to adjust to the best cutting depth at the initial stage of pipe manufacturing, and in order to judge the cutting result. Stop the pipe making, take a gas cut sample of the inner surface of the cut part, and if there is too much or too little cut, open the pipe in the part corresponding to the installation position of the cutting tool.
This is a trial-and-error process in which shims, etc. are placed on the mounting surface of the tool, fine adjustments are made to the height of the tool, and the pipe is made again, which is a problem that is the main cause of a decrease in yield and the operating rate of the pipe manufacturing equipment as a whole. .

In recent years, continuous pipe making has become practiced, and cutting conditions have come to be changed during pipe making.

For example, as in Japanese Utility Model Application Publication No. 61-109614, there is a bead cutting device in which a positioning cylinder and a detector are built in to adjust the cutting depth of an inner cutting tool. According to this method, it is possible to incorporate a positioning device into the bead cutting device itself for a relatively large pipe diameter (150A). However, when it comes to small-diameter bead cutting equipment, for example, 50 to 100A, storing the hydraulic cylinder, detector, associated hydraulic hoses, and cables inside the bead cutting equipment will exceed the size limit, and the cutting depth will exceed the limit. It was not possible to have a built-in adjustment device.

In addition, even in conventional devices with a built-in cutting depth adjustment device, there were many problems with the positioning drive device due to the harsh environment inside the pipe being manufactured, and there were also problems in terms of reduced reliability and cost. As for the cutting depth adjusting means, providing the cutting tool itself with an elevating function has the disadvantage that a gap is created in the elevating part, causing chatter during cutting, and it is not possible to obtain desirable results in terms of product quality.

[Problem that the invention attempts to solve]

The present invention solves the problem that it is not possible to construct an internal bead cutting device for small diameters with a cutting depth adjustment function by extending the conventional technology, and the use of the drive device and detector in the adverse environment inside the pipe during pipe manufacturing. The purpose of the present invention is to solve the problem of deterioration of equipment reliability due to the above problems and to provide a small and highly reliable internal bead cutting device.

[Means for solving problems]

In the present invention, two upper rollers 2, 3 and a cutting tool 4 are provided at an interval in the longitudinal direction of the steel pipe on the upper part of a cutting device main body 1 disposed in an ERW steel pipe, and the cutting device In an inner bead cutting device for an electric resistance welded steel pipe in which a lower roller 5 movable in the radial direction of the steel tube is provided at the bottom of a main body 1, an elevating device 6 is provided in the cutting device main body 1 to move one upper roller up and down. , a positioning drive device 7 for adjusting the lifting position of the lifting device 6 is disposed outside the steel pipe 8, and the positioning drive device 7 and the lifting device 6 are connected by a drive shaft 9. The gist is a device for cutting the inner bead of a sewn steel pipe.

〔Example〕

The present invention will be explained in detail below based on one embodiment.

1 to 5 show an embodiment of the present invention, in which a movable lift that is moved up and down by a lifting device is installed on the top of a cutting device main body 1 extending in the longitudinal direction within a steel pipe 8. A roller 2 and a fixed upper roller 3 are arranged at intervals in the longitudinal direction of the cutting device main body 1, and the fixed upper roller 3 is rotatably attached to the cutting device main body 1 by a horizontal axis, and A cutting tool 4 is attached to the top of the
Furthermore, a lower roller 5 is arranged at the lower part of the cutting device main body 1 between the movable upper roller 2 and the fixed upper roller 3, and the lower roller 5 is rotatably attached to the tip of the lower roller support arm 12. The base end of the lower roller support arm 12 is connected to the pin 1 with respect to the cutting device main body 1.
3, it is rotatably attached. In addition, a hydraulic cylinder 14 for pressing the lower roller is attached to the cutting device main body 1.
is fixed, and a hydraulic cylinder 14 for pressing the lower roller
The piston rod 15 is engaged with the upper surface of the intermediate portion of the lower roller support arm 12, and the hydraulic cylinder 14
As a result, the lower roller support arm 12 is pushed down about the pin 13, and the lower roller 5 is pressed against the lower part of the inner surface of the steel pipe 8.

The end of the cutting device main body 1 is connected to the other end of a rod 17 whose one end is fixed to the support device 16, so that even if the steel pipe 8 moves in the axial direction or rotates in the circumferential direction, the cutting device The main body 1 is restrained from moving or rotating, and the cutting device main body 1 is moved upward by the reaction force of the lower roller 5, so that the movable upper roller 2 and the fixed upper roller 3 are placed on the upper part of the inner surface of the steel pipe 8. The three rollers that are pressed, that is, located at the corners of the triangle, are all pressed against the inner surface of the steel pipe 8 and are balanced, so that the cutting device main body 1 is supported in a stable state within the steel pipe 8. , stable cutting can be performed.

As shown in FIG. 1, the circumferential surfaces of the movable upper roller 2 and fixed upper roller 3 are recessed in a U-shape at the center so that they do not contact the bead directly, but contact the base material surfaces on both sides of the bead. ing. Movable upper roller 2,
The fixed upper roller 3 and the cutting tool 4 are aligned in the axial direction of the steel pipe 8, and in this embodiment, the cutting tool 4 is arranged between the two upper rollers 2 and 3.
The cutting amount of the cutting tool 4 is determined by the mounting height of the two upper rollers 2 and 3 and the cutting tool 4.

The movable upper roller 2 is housed in a rectangular cylindrical holder 21 and is rotatably mounted on a horizontal axis, and the holder 21 is fitted into a rectangular cylindrical guide portion 22 provided in the cutting device main body 1 so as to be freely raised and lowered. A ball screw threaded rod 24 extending in the longitudinal direction of the cutting device main body 1 is screwed into the wedge 23 which is fitted together and arranged at the lower part of the holder 21 .
A bearing 25 whose both ends are fixed to the cutting device main body 1
It is rotatably supported by. Further, the wedge 23 is placed on a slide plate 26 fixed to the cutting device main body 1, and the wedge 23 is placed on the slide plate 26 fixed to the cutting device main body 1.
This prevents the wedge 23 from rotating, and
The wedge 23 is configured to support a load acting on the wedge 23 from above, and is moved in the front-back direction (longitudinal direction of the steel pipe) by the ball screw rod 24, and the holder 21 is moved upward by the wedge 23. The elevating device 6 is constituted by the above.

A rotational position detector 28 is connected to the shaft of the servo motor 27, and an output part of a comparator 29, which has an input part for a control command and an input part for a detection signal of the rotational position detector 28, is an input part of the servo driver 30. The output section of the servo driver 30 is further connected to the control section of the servo motor 27 to constitute a positioning drive device 7, and the positioning drive device 7 is disposed outside the steel pipe 8.

One end of a flexible drive shaft 31 is connected to the output shaft of the servo motor 27 in the positioning drive device 7, and the other end of the flexible drive shaft 31 is connected to the input shaft of a reducer 32 fixed to the cutting device main body 1. The flexible drive shaft 31 and the rigid drive shaft 33 constitute a drive shaft 9.The flexible drive shaft 31 and the rigid drive shaft 33 constitute a drive shaft 9.

When the upper roller height control command is given to the comparator 29,
The comparator 29 compares the command value △h with the rotational position detector 2.
8 and outputs the deviation Δp to the servo driver 30. Servo driver 30
outputs a signal corresponding to the deviation Δp to the servo motor 27, and as a result, the servo motor 27 is driven until the difference between the value fed back from the rotational position detector 28 and the command value becomes zero, and the servo motor 27
The amount of rotation is reduced by the speed reducer 32 via the drive shaft 9 and transmitted to the ball screw threaded rod 24, which moves the wedge 23 and supports the upper roller 2 by the movement of the wedge 23. The holding holder 21 is moved up and down.
Since the upper roller 2 and the rotational position detector 28 are mechanically coupled, the amount of elevation of the upper roller 2 can be accurately detected by the rotational position detector 28.

Next, the amount of cutting of the bead 18 by the cutting tool 4 will be explained.

FIG. 5A shows the initially set values, and the position of the wedge 23 at this time is the center position shown in FIG.

If you want to detect a shortage of cutting amount (uncut) and correct the cutting amount, control the servo motor 27 to move the wedge 23 to the left side in FIG. 3, that is, in the direction in which the movable upper roller 2 descends. In order to balance the posture of the cutting device, the cutting device main body 1 rotates counterclockwise around the fixed upper roller 3 by the amount that the movable upper roller 2 descends, and all three rollers come into contact with the inner surface of the pipe. It moves like this. As a result, the attitude of the cutting device main body 1 is upward to the right as shown in FIG. 5B. The connecting portion between the cutting device main body 1 and the rod 17 has flexibility so as to allow the attitude of the cutting device main body 1 to be changed. Therefore, the amount of cutting is determined by the heights of the upper rollers 2, 3 and the cutting tool 4.

Also, from the rotation amount of the rotation position detector 28, the tool 4
If the correspondence is made so that the amount of elevation can be converted, the comparator 2
If set to 9, the amount of cutting can be automatically adjusted.

If the amount of cutting is excessive, it is clear from the above explanation that the movable upper roller 2 should be raised as shown in FIG. 5C, and the cutting tool should be relatively lowered. In order to obtain a reliable response to such a small amount of correction, the cutting device main body 1, which serves as a reference, is required to have high rigidity with little deflection.

When implementing the present invention, the lifting device 6 and the positioning drive device 7 may have any structure other than those shown in the drawings. Further, instead of the rigid drive shaft 33, a flexible drive shaft may be used in this portion.

[Effect of idea]

According to the present invention, the cutting device main body 1 of the inner bead cutting device is provided with the lifting device 6 for lifting and lowering one of the upper rollers, and the positioning drive device 7 for adjusting the lifting position of the lifting device 6 is provided on the outside of the steel pipe 8. Since the positioning drive device 7 and the lifting device 6 are connected by the drive shaft 9, the portion accommodated in the steel pipe 8 in the internal bead cutting device can be greatly reduced in size. The positioning drive device 7 can be easily applied to inner bead cutting in small-diameter electric resistance welded steel pipes, and the positioning drive device 7 is
Bad environment inside steel pipe 8 during pipe making (water, scale, heat,
Since the positioning drive device 7 is not affected by welding electromagnetic noise (welding electromagnetic noise), highly reliable and stable control is possible, and the life of the positioning drive device 7 can be extended. Furthermore, although such a bead cutting device is usually prepared for each steel pipe size, according to the present invention, only one set of positioning drive device is required, which is advantageous in terms of equipment cost and running cost. Therefore, the internal bead cutting device of the present invention is extremely advantageous in terms of miniaturization, improved reliability, and reduced cost.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional side view showing the state of use of the inner bead cutting device for electric resistance welded steel pipes, and Figure 2 is the inner bead cutting device for electric resistance welded steel pipes. FIG. 3 is a vertical sectional side view enlarging a part of FIG. FIG. 2 is a schematic side view showing the relationship between the vertical position of the movable upper roller and the position of the cutting tool with respect to the steel pipe. FIG. 6 is a partially longitudinal side view showing a conventional internal bead cutting device for electric resistance welded steel pipes. In the figure, 1 is the cutting device main body, 2 is the upper roller,
3 is an upper roller, 4 is a cutting tool, 5 is a lower roller, 6 is a lifting device, 7 is a positioning drive device, 8 is a steel pipe, 9
12 is a drive shaft, 12 is a lower roller support arm, 13 is a pin, 14 is a hydraulic cylinder for pressing the lower roller, 16 is a support device, 17 is a rod, 18 is a bead, 21 is a holder, 22 is a guide portion, 23 is a wedge, 24 is a ball screw rod, 27 is a servo motor, 28 is a rotational position detector, 29 is a comparator, 30 is a servo driver, 31 is a flexible drive shaft, and 32 is a speed reducer.

Claims (1)

[Scope of utility model registration request] Two upper rollers 2, 3 and a cutting tool 4 are provided at the upper part of a cutting device main body 1 disposed in an ERW steel pipe, and are spaced apart from each other in the longitudinal direction of the steel pipe.
In an inner bead cutting device for an electric resistance welded steel pipe, in which a lower roller 5 movable in the radial direction of the steel pipe is provided at the lower part of the cutting device main body 1, an elevating device 6 moves one upper roller up and down in the cutting device main body 1. A positioning drive device 7 for adjusting the vertical position of the lifting device 6 is disposed outside the steel pipe 8, and the positioning drive device 7 and the lifting device 6 are connected to a drive shaft 9.
An internal bead cutting device for electric resistance welded steel pipes, characterized in that the inner bead cutting device is connected by.