JP2018144197A - Pipe surface polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe surface polishing method that enables control of a roll-separating force of a flap wheel to be performed by an inexpensive method when a pipe surface is polished by the flap wheel.SOLUTION: When a load current of a drive motor 3 of a flap wheel 1 reaches a lower limit, a command to lower the flap wheel 1 to a ball screw 5 is issued for a predetermined of period of time from a controller 7. When the load current reaches an upper limit, a command to lift the flap wheel 1 to the ball screw 5 is issued for a predetermined of period of time from the controller 7. Thereby, the flap wheel 1 is moved upward and downward via the ball screw 5 by time control to keep a roll-separating force of the flap wheel 1 proper. Thus, the pipe surface is polished.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipe surface polishing method, and in particular, to a pipe surface polishing method capable of easily controlling the rolling force of a flap wheel when polishing the surface of a stainless steel pipe with a flap wheel, by an inexpensive method. Is.

  For example, a stainless steel pipe is manufactured as follows.

  As shown in FIG. 4, the unpolished pipe 12 from the automatic pipe feeder 11 is sent to the horizontal polishing machine 13 and the vertical polishing machine 14, where it is roughly cut and then sent to the finish polishing machine 16 through the intermediate table 15. Here, it is finally polished to the target surface roughness, and then sent to the next process through the inspection table 17 to become a product stainless steel pipe.

  The horizontal polishing machine 13, the vertical polishing machine 14, and the finish polishing machine 16 each include a plurality of flap wheels 18 that are installed at intervals in the line direction.

  As shown in FIG. 5, the flap wheel 18 is composed of a cylindrical core member 19 having sandpaper 20 attached radially around it, and is rotated by a motor (see FIG. 1) as shown in FIG. 6. It is attached to the shaft 21 (see Patent Document 1). The roughness of the sandpaper 20 of the flap wheel 18 in the horizontal polishing machine 13, the vertical polishing machine 14, and the finish polishing machine 16 is finely formed in stages from the upstream side to the downstream side.

  The rotating shaft 21 of the flap wheel 18 in the horizontal polishing machine 13 and the finish polishing machine 16 is parallel to the line direction (see FIG. 1) (see FIG. 4), and the rotating shaft 21 of the flap wheel 18 in the vertical polishing machine 14 is It is orthogonal to the line direction (see FIG. 4).

  As shown in FIG. 7, the flap wheel 18 is attached to a ball screw 22 that converts rotational motion into linear motion.

  The ball screw 22 includes a screw shaft 23 and a motor 24 that rotates the screw shaft 23, and the flap wheel 18 moves up and down with respect to the unpolished pipe 12 by the rotation of the screw shaft 23. The reduction force on the polishing pipe 12 can be adjusted.

Japanese Utility Model Publication No. 5-24268 JP 2002-283231 A

  As a method for controlling the rolling force of the flap wheel 18 to the unpolished pipe 12, a method of changing the motor 24 of the ball screw 22 to a servo motor and finely adjusting the vertical movement of the flap wheel 18 by pulse control can be considered. This method is effective and feasible, but is expensive.

  In Patent Document 2, when the polishing reduction force is controlled by the current flowing in the motor that rotates the polishing foil of the polishing apparatus, the motor load current is divided into the no-load portion and the polishing actual load portion, and when the polishing foil is idle. Measure the current in the no-load part, recognize when the load current has risen sharply as reaching the workpiece, and set the current in the no-load part in advance according to the type of material to be polished. An automatic polishing pressure control method in a polishing apparatus is disclosed in which the rolling-down position of the polishing foil is controlled so that a current obtained by adding the current of the load portion flows to the motor. However, such a method is complicated to control.

  Accordingly, an object of the present invention is to provide a pipe surface polishing method capable of easily controlling the rolling force of the flap wheel when polishing the pipe surface with the flap wheel by an inexpensive method.

  The present invention has been made to achieve the above object, and is characterized by the following.

  The invention according to claim 1 is a pipe surface polishing method for polishing a pipe surface with a flap wheel that moves up and down by a ball screw, and when a load current of a drive motor of the flap wheel becomes a lower limit value, a predetermined time, A command to lower the flap wheel is issued to the ball screw, and when the load current reaches an upper limit value, a command to raise the flap wheel is given to the ball screw for a predetermined time, and thus the ball is controlled by time control. The flap wheel is moved up and down via a screw to properly maintain the rolling force of the flap wheel, thus polishing the pipe surface.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the reduction ratio of the drive motor for the ball screw is increased.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the time control of the ball screw is detected when the presence or absence of the pipe at the installation position of the flap wheel is detected and the pipe is detected. It has the feature in performing.

  The invention described in claim 4 is characterized in that, in the invention described in any one of claims 1 to 3, the pipe is a stainless steel pipe.

  According to the present invention, the rolling force applied to the pipe surface of the flap wheel can be controlled inexpensively and easily by moving the ball screw attached with the flap wheel up and down by time control.

  Further, according to the present invention, by increasing the reduction ratio of the ball screw drive motor, there is no possibility that the rolling force on the pipe surface of the flap wheel is out of the management range.

  Moreover, according to this invention, the malfunction of a ball screw can be eliminated by detecting the presence or absence of the pipe in the installation position of a flap wheel.

It is a schematic side view which shows the pipe surface grinding | polishing method of this invention. It is a schematic front view which shows the state which installed the pipe detector in the pressing roll in the installation position of a flap wheel. It is a graph which shows an example of time control of a ball screw. It is a figure which shows the grinding | polishing process of a stainless steel pipe. It is a perspective view which shows a flap wheel. It is sectional drawing which shows a flap wheel. It is a schematic side view which shows the flap wheel attached to the ball screw.

  One embodiment of the pipe surface polishing method of the present invention will be described with reference to the drawings.

  Hereinafter, a stainless steel pipe will be described as an example, but a pipe other than a stainless steel pipe may be used.

  FIG. 1 is a schematic side view showing a pipe surface polishing method of the present invention, FIG. 2 is a schematic front view showing a state in which a pipe detector is installed on a pressing roll at a flap wheel installation position, and FIG. It is a graph which shows an example of time control.

  1 and 2, reference numeral 1 denotes a flap wheel for polishing the surface of the stainless steel pipe 2, and the structure thereof is the same as that shown in FIGS. 4 and 5. Reference numeral 3 denotes a drive motor for the flap wheel 1. A ball screw 4 moves the flap wheel 1 up and down. The ball screw 4 includes a screw shaft 5 and a motor 6 with a speed reducer that rotates the screw shaft 5, and the flap wheel 1 moves up and down with respect to the unpolished stainless steel pipe 2 by the rotation of the screw shaft 5.

  A controller 7 has a function of moving the flap wheel 1 up and down via the ball screw 4 by time control. That is, when the load current of the drive motor 3 of the flap wheel 1 reaches the lower limit value, the controller 7 issues a command for lowering the flap wheel 1 to the ball screw 4 for a predetermined time, while the load current exceeds the upper limit value. When the value is reached, a command to raise the flap wheel 1 is issued to the ball screw 4 for a predetermined time. Thereby, the rolling force on the pipe surface of the flap wheel can be maintained in an appropriate management range.

  Reference numeral 8 denotes a non-contact type pipe detector that detects the presence or absence of the stainless steel pipe 2 at the installation position of the flap wheel 1 (see FIG. 2), and is provided on the pressing roll 9 of the stainless steel pipe 2. By providing the pipe detector 8, malfunction of the ball screw 4 can be eliminated. In FIG. 2, reference numeral 10 denotes a lower roll of the stainless pipe 2.

  FIG. 3 shows an example of time control of the ball screw 4. In this case, the lower limit value of the load current is 26.5 A, and the lower limit value of the load current is 28.5 A, which is the load current management range. The vertical movement time of the flap wheel 1, that is, the rotation time of the screw shaft 5 is 0.05 seconds.

  In addition, if the reduction ratio of the motor 6 of the ball screw 4 is small, it is difficult to stop due to inertia, and as a result, the control range of the load current may be exceeded, but this problem can be solved by increasing the reduction ratio of the motor 6. Is resolved.

  As apparent from FIG. 3, the load current of the drive motor 3 of the flap wheel 1 is changed from the motor 3 of the ball screw 4 to a servo motor by moving the flap wheel 1 up and down via the ball screw 4 by time control. However, compared with the case where the vertical movement of the flap wheel 1 is finely adjusted by pulse control, it can be easily and inexpensively maintained within the appropriate management range.

  As described above, according to the present invention, it is possible to control the rolling force on the pipe surface of the flap wheel 1 inexpensively and easily by vertically moving the ball screw 4 to which the flap wheel 1 is attached by time control. Can be done.

  Further, according to the present invention, by increasing the reduction ratio of the drive motor 6 of the ball screw 4, there is no possibility that the rolling force on the pipe surface of the flap wheel 1 falls outside the management range.

  Moreover, according to this invention, the malfunction of the ball screw 4 can be eliminated by detecting the presence or absence of the stainless steel pipe 2 at the installation position of the flap wheel 1 by the pipe detector 8.

1: Flap wheel 2: Stainless steel pipe 3: Motor 4: Ball screw 5: Screw shaft 6: Motor 7: Controller 8: Pipe detector 9: Pressing roll 10: Lower roll 11: Automatic pipe feeder 12: Unpolished pipe 13: Horizontal polishing machine 14: Vertical polishing machine 15: Intermediate table 16: Finish polishing machine 17: Inspection table 18: Flap wheel 19: Core material 20: Sand paper 21: Rotating shaft 22: Ball screw 23: Screw shaft 24: Motor

Claims (4)

In the pipe surface polishing method of polishing the pipe surface with a flap wheel that moves up and down by a ball screw,
When the load current of the drive motor of the flap wheel reaches a lower limit value, a command is issued to lower the flap wheel to the ball screw for a predetermined time, and when the load current reaches an upper limit value, the predetermined time, A command to raise the flap wheel to the ball screw is issued, and thus the flap wheel is moved up and down via the ball screw by time control to properly maintain the rolling force of the flap wheel, and thus the pipe A pipe surface polishing method, characterized by polishing a surface.   The pipe surface polishing method according to claim 1, wherein a reduction ratio of a drive motor of the ball screw is increased.   3. The pipe surface polishing method according to claim 1, wherein when the pipe is detected at the position where the flap wheel is installed, and the pipe is detected, the time control of the ball screw is performed. .   The pipe surface polishing method according to any one of claims 1 to 3, wherein the pipe is a stainless steel pipe.

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