JPH0611696Y2 - Inner bead cutting device for ERW pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an inner bead cutting device for an electric resistance welded pipe.

[Prior Art] An inner bead cutting device for an electric resistance welded pipe inserts and holds a table or a dolly attached with a cutting blade into the pipe, and performs relative movement between the cutting blade and the electric resistance welded pipe to perform cutting of the inner bead. It is a thing. In recent years, a cutting device has been developed and used that can adjust the position of the cutting blade and remotely control the cutting load according to the change of the pipe inner diameter for the purpose of improving the work efficiency. Actual Kaisho 6
2-150016 is an example of this, which will be described with reference to FIG. The carriage 3 and the movable carriage 6 are inserted into the electric resistance welded pipe 1 by the holder 10, and the cylinder rods 8a and 8b of the hydraulic cylinders 7a and 7b provided on the movable carriage 6 are raised.
The wheels 4 of the carriage 3 and the wheels 9 of the movable carriage 6 are brought into contact with the inner wall of the electric resistance welded pipe 1 to set the carriage 3 and the movable carriage 6. As a result, the cutting edge of the cutting tool 5 attached to one end of the carriage 3 is set at a position where the inner bead 2 is cut. After that, when the electric resistance welded pipe 1 is moved in the direction of the arrow, the wheels 4 and 9 roll to hold the carriage 3 and the moving carriage 6 in place, and the inner bead 2 is cut and removed. Become.

[Problems to be solved by the invention] Since the conventional inner bead cutting device extends the cylinder rod of the hydraulic cylinder of the moving carriage to bring the wheel of the moving carriage and the wheel of the moving carriage into contact with the inner wall of the pipe, the maximum applicable The inner diameter of the pipe will depend on the stroke of the hydraulic cylinder. However, when the pipe inner diameter is the same, the pipe outer diameter is determined by the wall thickness. Therefore, if the variation range of the pipe wall thickness is large, a pipe wall thickness range that cannot be applied with the same cutting device occurs. In addition, even for a cutting device that can handle the entire wall thickness range with a pipe with a certain outer diameter, if it is used for a pipe with a large outer diameter, a wall thickness range that cannot be supported will occur.Therefore, we have an inner bead cutting device for each outer diameter pipe. , If the pipe wall thickness is not compatible with pipes of the same outer diameter, it was necessary to deal with it by replacing the inner bead cutting device or replacing the bogie. That is, the conventional device has a problem in that it is necessary to have a large number of inner bead cutting devices, and in the case of a certain size, it is necessary to replace the cutting device or the like, and thus work efficiency cannot be improved.

[Means for Solving the Problems] The present invention is intended to solve the above problems, and an inner bead of an electric resistance welded pipe including a carriage for holding a bead cutting tool and a movable carriage for supporting the carriage. In the cutting device, a plurality of hydraulic cylinders, in which cylinder rods are horizontally arranged in the longitudinal direction of the carriage, are connected in series in the longitudinal direction, and a lower portion of the carriage that is formed on the cylinder rod side and is opened downward And an L-shaped link, one end of which is slidably connected to the tip end of the cylinder rod in the vertical direction and the other end of which is hinge-connected to a moving carriage, and the L-shaped link provided in the recess of the carriage. A bead cutting device for an inner surface of an electric resistance welded pipe, which comprises a fulcrum shaft which is rotatably supported around a bent portion, and the movable carriage is capable of entering and leaving the concave portion of the carriage by an L-shaped link. Is.

[Operation] When the cylinder rod is extended, the L-shaped link rotates counterclockwise about the fulcrum shaft, and the distance between the carriage and the movable carriage becomes smaller. That is, it can be applied to a small tube inner diameter. On the contrary, when the cylinder rod is reduced,
The L-shaped link rotates clockwise around the fulcrum axis,
The distance between the dolly and the moving dolly increases. That is, it can be applied to a large pipe inner diameter.

Since there is no restriction on the size of the carriage in the longitudinal direction, by installing a hydraulic cylinder in the horizontal direction, if one hydraulic cylinder cannot provide the necessary pushing force, the hydraulic cylinder will move in the longitudinal direction of the carriage. The required pushing force can be obtained by connecting a plurality of hydraulic cylinders in series.

Since the link is formed in an L-shape that bends at 90 °, even if the rotation angle of the link changes, the force of the link pushing the moving carriage downward becomes constant. That is, the force (cutting load) for holding the cutting edge upward is constant. Further, by increasing the ratio of the arm length on the side of the movable carriage and the arm length on the side of the cylinder rod which form the link, it is possible to increase the distance adjustment range between the carriage and the movable carriage, that is, the pipe inner diameter adjustment range.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First
The figure shows a vertical sectional view of the device of the present invention. Reference numeral 1 is an electric resistance welded pipe, and 2 is a weld bead formed on the inner surface of the electric resistance welded pipe. The dolly 3 has wheels 4 on its upper part, and a bead cutting bite 5 is attached to one end thereof. Hydraulic cylinders 7a, 7b and 7c are provided in series at the lower part of the carriage 3 so that the cylinder rod 8 is horizontal. A lower portion of the carriage 3 is provided with a concave portion 17 opened downward in front of the cylinder rod. A rod head 13 is provided at the tip of the cylinder rod 8, and a horizontal elongated hole 14 is provided in the head 13, and a pin 15 fixedly mounted in a recess penetrates the elongated hole 14. , The rod head 13 is regulated to move in the horizontal direction.
Reference numeral 11 is an L-shaped link, which is a fulcrum shaft 1 provided in the recess 17.
2, the bent portion is rotatably attached. And
One end of the L-shaped link 11 is slidably connected to a vertical elongated hole 16 formed in the rod head 13, and the other end is hinged to the moving carriage 6. Reference numeral 9 is a wheel of the moving carriage 6.

Next, a method of using the device of the present invention will be described. When the cylinder rod 8 is extended, the end portion of the L-shaped link 11 that is connected to the vertical elongated hole 16 of the rod head 13 is guided by the elongated hole 16 to move downward, and the L-shaped link 11 is a fulcrum. It rotates counterclockwise about the shaft 12. The moving carriage 6 is pulled up, and the distance between the carriage 3 and the moving carriage 6 is reduced. When the cylinder rod 8 is contracted, L
The end portion of the L-shaped link 11 that is connected to the vertical elongated hole 16 of the rod head 13 is guided by the elongated hole 16 and moves upward, and the L-shaped link 11 moves clockwise about the fulcrum shaft 12. Rotate. The moving carriage 6 is pushed down, and the distance between the carriage 3 and the moving carriage 6 increases. That is, when the pipe wall thickness becomes thick and the inner diameter becomes small, the cutting device is set by extending the cylinder rod 8, and when the pipe wall thickness becomes thin and the inner diameter becomes large, the cylinder rod 8 is moved. Set the cutting device by shortening.

Next, the mechanism of the L-shaped link will be described. In FIG. 2, the attraction force of the hydraulic cylinder 7 is F, the pushing force (cutting reaction force) of the moving carriage is P, the length of the arm on the cylinder rod side is L, the length of the arm on the moving carriage side is R, and the moment. Let r be the side of the hydraulic cylinder, r be the side of the moving carriage, and θ be the inclination angle of the link. The intersection angle of the two arms is a right angle, and F always works in the horizontal direction. Since the moments around the fulcrum axis of the L-shaped link are balanced, F = Pr (1) Therefore, Therefore, the push-down force (cutting reaction force) P of the moving carriage is a value obtained by multiplying the attractive force F of the hydraulic cylinder by the link arm ratio L / R regardless of the inclination angle θ of the link. That is,
The pushing force (cutting reaction force) P of the moving carriage has a proportional relationship with the hydraulic pressure setting pressure. In addition, the stroke amount of the dolly (up and down amount)
Can be increased by shortening the arm length L on the cylinder rod side and lengthening the arm length R on the moving carriage side.

Although FIG. 1 shows the case where there are three hydraulic cylinders, the number of hydraulic cylinders may be increased or decreased according to the required pushing force (cutting reaction force) of the moving carriage. In particular, when the inner diameter of the pipe is small, a hydraulic cylinder with a small pressure receiving area (bore diameter) must be used, and the pushing force that one hydraulic cylinder can output becomes small. For this reason, when the push-up force (push down force of the moving carriage) for setting the cutting edge of the cutting tool on the inner bead is insufficient, a plurality of hydraulic cylinders can be provided in the longitudinal direction of the pipe axis without size restrictions. Therefore, it can be applied to pipes with a small inner diameter.

[Advantage of the Invention] In the present invention, since the trolley is moved up and down by the L-shaped link, the applicable pipe inner diameter range can be expanded as compared with the conventional device by appropriately setting the arm ratio of the link. be able to. Therefore, it is possible to reduce the number of inner bead cutting devices possessed as compared with the conventional one, and since it is not necessary to replace the cutting devices and the like with the same pipe outer diameter, work efficiency is improved. Since the hydraulic cylinders are laid horizontally in the length direction of the trolley, which has few dimensional restrictions, it is easy to increase the number of hydraulic cylinders and the pushing force (cutting reaction force) of the trolleys can be increased easily.
Particularly, a remarkable effect can be obtained in a small-diameter thick-walled steel pipe.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of the inner bead cutting device of the present invention, and FIG.
FIG. 3 is a front view of the L-shaped link of the present invention, and FIG. 3 is a vertical sectional view of a conventional inner bead cutting device. 3 ... Truck, 4 ... Wheel, 5 ... Cutting tool, 6 ... Movable carriage, 7a, 7b, 7c ... Hydraulic cylinder, 8 ...
Cylinder rod, 9 ... Wheel, 11 ... L-shaped link, 12 ... Support shaft, 13 ... Rod head, 16 ...
Slotted hole, 17 ... recess.

Front page continuation (72) Inventor Michiaki Yoshida Marunouchi 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Tube Co., Ltd. (72) Akio Sato 1-2 Marunouchi Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co. In-house Examiner Hiromitsu Tanaka (56) Bibliography Sho 61-109617 (JP, U) JP 60-51965 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. An inner bead cutting device for an electric resistance welded pipe comprising a carriage for holding a bead cutting bite and a movable carriage for supporting the carriage, wherein a cylinder rod is arranged horizontally in the longitudinal direction of the carriage and the longitudinal direction is set. A plurality of hydraulic cylinders connected in series with each other, a recess formed in the cylinder rod side of the lower part of the trolley, which is opened downward, and one end slidably coupled to the tip end of the cylinder rod in the vertical direction, The L-shaped link, the other end of which is hingedly connected to the moving carriage, and a fulcrum shaft, which is provided in the recess of the carriage and rotatably supports the L-shaped link around its bent portion, has a L-shaped moving carriage. A bead cutting device for an inner surface of an electric resistance welded pipe, which is capable of entering and leaving a concave portion of a trolley by a character-shaped link.