JPH11138400A - Grinding device for welded part in inner surface of piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and stably grind reverse side beads, and enhance grinding properties. SOLUTION: A grinding wheel 31 is disposed while being perpendicularly intersected with reverse beads 33, there causes no change in grinding resistance at the time of up-cutting/down-cutting, grinding is carried out stably, a device 34 at the side of the grinding wheel is clamped by the straight pipe part 32a of a pipeline 32, any non-conformity such as the slipping of a grinding device due to grinding resistance at the time of grinding is eliminated, pressing force caused by the revolutions of the grinding wheel is accurately estimated, grinding properties are thereby enhanced, accurate grinding at the high speed is made possible, a motor 46 for pressing the grinding wheel is controlled based on detected information from a tachogenerator 51 and a pipeline inner surface shape measurement sensor 48 so as to allow the grinding wheel to be controlled in feeding rate, and reverse side beads 33 are thereby automatically ground as far as the surface of parent material 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for grinding a welded portion of a pipe inner surface, which automatically grinds only a backwash located at a welded portion of the pipe inner surface.

[0002]

2. Description of the Related Art A conventional pipe inner surface welding portion grinding apparatus will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing a configuration of a main part of a conventional pipe inner surface welding portion grinding device, FIG. 6 is a system configuration of an entire pipe inner surface welding portion grinding device, and FIG. 7 is a control flowchart.

[0003] As shown in the figure, a grindstone 3 installed in the same direction as a backwash 2 of an inner welded portion of a pipe 1 is driven by a grindstone drive motor 5 installed outside the apparatus via a torque tube 4. . Since the pressing force of the grindstone 3 during grinding is proportional to the drive current of the grindstone driving motor 5, the grindstone pressing motor 7 is controlled so that the pressing force of the grindstone 3 becomes constant by the current monitor value of the grindstone driving servo amplifier 6. Control.

Further, the grinding device main body 8 is clamped by the clamp mechanism 9 at the straight pipe portion 1a and the tapered portion 1b on the inner surface of the pipe 1, and the grinding device main body 8 is fixed. In the present grinding apparatus, the output torque of the grindstone circumferential direction drive motor 10 is transmitted to the grindstone circumferential direction drive internal gear (fixed side) 11 to rotate the grindstone 3 in the circumferential direction. Further, by transmitting the output torque of the grinding wheel axial driving motor 12 to the grinding wheel axial driving ball screw 13, the grinding wheel 3 supported on the pedestal of the grinding wheel axial driving ball screw 13 is moved in the axial direction. Similarly, the output torque of the grinding wheel pressing motor 7 is transmitted to the grinding wheel pressing ball screw 14, and pushes or releases the grinding wheel 3 supported on the pedestal of the grinding wheel pressing ball screw 14 against the backwash 2.

[0005] Grinding of the backwash 2 of the inner welded portion of the pipe 1 is performed according to the control flowchart of FIG. In other words, the control panel 17 controls the grindstone circumferential direction drive motor 10 in accordance with a command from the control computer 16 so that the pipe inner surface shape measurement sensor 15 installed on the side surface of the grindstone 3 follows the entire circumference of the inner surface of the pipe 1. Then, the motor 12 for driving the grinding wheel in the axial direction is controlled to move in the axial direction by a set amount, and then the entire circumference of the inner surface of the pipe 1 is copied.

[0006] In the following sequence in the pipe shape measurement (S
By performing 1), the inner surface of the pipe 1 is measured. The shape data of the inner surface of the pipe 1 is taken into the control computer 16 by the pipe inner surface shape measurement sensor signal converter 18 and subjected to control calculation to inscribe the back wave start position 19, the back wave end position 20 and the base material surface 22. A virtual plane 21 is calculated. The control computer 16 performs Uranami grinding (S2) by force control according to the shape data of the inner surface of the pipe 1 so that the grindstone 3 does not grind the base material surface 22.

The pressing force of the whetstone 3 against the inner surface of the pipe 1 is as follows:
The estimation is made based on the current value output from the grinding wheel driving servo amplifier 6 to the grinding wheel driving motor 5. When the pressing force (current value) of the grindstone 3 becomes larger than the target, the control computer 16 sends a command to separate the grindstone 3 from the inner surface of the pipe 1 via the signal converter 23 and the control board 17 to the grindstone pressing motor 7. Output to When the pressing force (current value) of the grindstone 3 becomes smaller than the target, the grindstone 3 is pressed against the inner surface of the pipe 1 in the same procedure.

In the above-described method, while keeping the pressing force of the grindstone 3 constant so that the grindstone 3 does not grind the base material surface 22,
Grinding is performed until the Uranami 2 reaches the virtual plane 21 over the entire circumference (S3, S4, S5). At this time, in order to prevent uneven wear of the grindstone 3, a command value for waving the grindstone 3 is output from the control computer 16 to the grindstone axial drive motor 12 via the signal converter 23 and the control panel 17, and To waving.

6, reference numeral 24 denotes a connector box, 25 denotes a hand-pass filter, 26 denotes a signal amplifier,
27 is an empty board.

[0010]

In the above-described conventional apparatus for grinding the welded portion of the inner surface of a pipe, since the grinding wheel 3 is oriented in the same direction as the backwash 2, the circumferential direction of rotation of the grinding wheel 3 and the rotational direction are the same. In this case, the grinding resistance acts in the direction of pressing the grindstone 3 against the base material surface 22, and in the case of a downcut in which the circumferential feed direction and the rotation direction of the grindstone 3 are opposite to each other, the grinding resistance changes the grindstone 3 to the base material surface 22.
Work in the direction of pushing back from. For this reason, the grinding resistance generated when grinding the base material surface 22 with the grindstone 3 acts as a disturbance in the direction in which the grindstone 3 is pressed / returned, and it is mechanically difficult to keep the pressing force of the grindstone 3 constant. there were.

Further, as shown in FIG. 5, the grinding device main body 8 is a mechanism for clamping the clamp mechanism 9 to the straight pipe portion 1a and the tapered portion 1b in the pipe 1. For this reason, there is a problem that the more the clamping force is increased, the more the force for pulling out the grinding device 8 acts on the grinding device body 8 and the more the grinding resistance cannot be sufficiently supported.

While the pressing force of the grindstone 3 is estimated based on the grindstone driving force, a drive system for rotating the grindstone 3 is constituted by a grindstone driving motor 5 and a torque tube 4. Therefore, the drive torque of the grindstone drive motor 5 measured by the grindstone drive servo amplifier 6 is the sum of the loss torque in the torque tube 4 and the drive torque of the grindstone 3. Therefore, the accurate driving torque of the grinding wheel 3, that is, the grinding wheel 3
There was a problem that it was not possible to measure the pressing force.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a construction of the present invention comprises a grindstone-side device having a grindstone disposed to intersect a backwash of a welded portion on the inner surface of a pipe, and a driving wheel for rotating the grindstone. A drive-side device incorporating a rotary drive unit to be driven, an elastic member connecting mechanism for connecting the grinding wheel-side device and the drive-side device, and the grinding wheel-side device provided in the grinding wheel-side device with a straight pipe portion of the pipe. A clamping device for clamping, a grindstone feeding means for moving the grindstone with respect to the backlash in the grindstone side device, a pressing force detection sensor for detecting a pressing force according to a rotation speed of the grindstone, and a start of the backwash A pipe state detection sensor for detecting a position and an end position and a virtual plane of the pipe inner surface, and controlling the grinding wheel feed means based on detection information of the pressing force detection sensor and the pipe state detection sensor to perform the grinding. Characterized by comprising the control device for controlling movement of the.

[0014]

FIG. 1 is a side sectional view of an apparatus for grinding a welded portion of an inner surface of a pipe according to an embodiment of the present invention, and FIG. FIG. 3 shows a plan cross section, FIG. 3 shows a system configuration, and FIG.

As shown in the figure, the grindstone 31 is arranged in a direction perpendicular to the backwash 33 on the inner surface of the pipe 32. Whetstone 3
1 is fixed to the straight pipe portion 32a of the pipe 32 by a clamp mechanism 35 as a clamp device. A grindstone driving motor 36 as a rotation driving means for rotating the grindstone 31 is connected to the grindstone 31 via a torque tube 37, and the drive side device 38 and the grindstone side device 34 provided with the grindstone driving motor 36 are elastic. They are connected by a spring mechanism 39 as a member connection mechanism.

The output torque of the grinding wheel drive motor 36 is controlled by the coupling 40, the torque tube 37, and the bevel gear 41.
Is transmitted to the grindstone 31 via. Since the grindstone 31 is arranged at right angles to the backwash 33, there is no influence of an external force acting on the grindstone 31 during upcut / downcut grinding, and stable grindability can be obtained.

If the pressing force of the grindstone increases while grinding the backwash 33 with the grindstone 31, the rotational speed of the grindstone driving motor 36 decreases. The change in the number of revolutions is used as a tachogenerator (tachogenerator: speed detector) 51 as a pressing force detection sensor.
And calculates the pressing force of the grindstone. The grinding wheel pressing motor 4 so that the calculated grinding wheel pressing force becomes constant.
6 is controlled. That is, the grindstone pressing motor 46 is controlled so that the grindstone 31 is pulled when the grindstone pressing force increases, and the grindstone 31 is pressed when the grindstone pressing force decreases.

By connecting the drive-side device 38 and the grindstone-side device 34 by a spring mechanism 39, a grinding device main body 71 is connected.
The length of the grindstone-side device 34 can be increased without impairing the curved pipe portion passageability. The clamp mechanism 35 is provided at a portion where the length is increased without impairing the passage of the grinding device body 71.
By installing the pipe, a structure that can be clamped by the straight pipe portion 32a of the pipe 32 is obtained.

The wheel driving torque output from the wheel driving motor 36 is transmitted to the wheel 31 via the torque tube 37 and the bevel gear 41. By incorporating the bevel gear 41 into the torque transmission system, the grindstone 31 can be installed and driven in a direction perpendicular to the backwash 33.

In the present grinding apparatus, the grinding wheel 31 is rotated in the circumferential direction by transmitting the output torque of the grinding wheel circumferential driving motor 42 to the grinding wheel circumferential driving internal gear 43 (fixed side). Also, by transmitting the output torque of the grinding wheel axial direction driving motor 44 to the grinding wheel axial direction driving ball screw 45, the grinding wheel 31 supported on the pedestal of the grinding wheel axial direction driving ball screw 45 is driven in the axial direction. Similarly, the output torque of the grinding wheel pressing motor 46 is transmitted to the grinding wheel pressing ball screw 47, and pushes or releases the grinding wheel 31 supported by the pedestal of the grinding wheel pressing ball screw 47 to the backwash 33.

After the grindstone side device 34 is positioned in the pipe 32, it is clamped by the clamp mechanism 35 to the straight pipe portion 32 a of the pipe 32. After the grinding wheel side device 34 is clamped, the pipe inner surface shape measurement sensor 48 as a piping condition detection sensor is moved by the grinding wheel circumferential direction driving motor 42 and the grinding wheel axial direction motor 44. Thereby, the shape of the inner surface of the pipe 32 is measured, and the back seam start position 49 and the back seam end position 50 are measured.
And a virtual plane 21 (see FIG. 7).

FIG. 4 is an improvement of the step (S2) of the backside grinding by the force control in FIG. Based on the measurement data of the back wave start position 49, the back wave end position 50, and the virtual plane 21, the tachometer 51 measures the grindstone rotation speed proportional to the grindstone pressing force (S11), and the analog / digital signal converter 52. The signal is converted and taken into the control computer 53. The control computer 53 presses the grinding wheel 31 via the digital / analog signal converter 56 onto the servo amplifier 55 of the grinding wheel pressing motor 46 so that the rotation speed of the grinding wheel 31 driven by the compressor 54 as the air supply source becomes constant. An axis command signal 57 is output.

The control computer 53 calculates the grindstone pressing value (S12) by the following command: (target grindstone rotation speed−tachogenerator output voltage) × gain. The pressing axis command signal 57 calculated in this manner is output to the servo amplifier 55, and the grindstone pressing motor 46 is controlled in accordance with the output.

At this time, the grindstone pressing motor 46 is controlled so that the grindstone 31 does not exceed the base material surface 58 (virtual plane 21). That is, an encoder signal 59, which is a rotation angle detection signal of the grinding wheel pressing motor 46, is taken into the control computer 53 by the pulse counter 60, and the grinding wheel 31
It is determined whether or not the grinding wheel 1 has been reached.
Is output from the base material surface 58. In this way, the backwash 33 on the inner surface of the pipe 32 is ground all the way to the base material surface 58.

[0025]

According to the present invention, there is provided an apparatus for grinding a welded portion of an inner surface of a pipe, comprising: a grindstone side device having a grindstone disposed so as to intersect a backlash of a welded portion of an inner surface of a pipe; and a rotation driving means for driving and rotating the grindstone. A drive-side device incorporated, an elastic member connection mechanism for connecting the grinding-wheel-side device and the driving-side device, and a clamp device provided on the grinding-stone-side device and clamping the grindstone-side device with a straight pipe portion of the pipe. A grindstone feeding means for moving the grindstone with respect to the backlash in the grindstone side device, a pressing force detection sensor for detecting a pressing force by the number of rotations of the grindstone, a start position and an end position of the backwash, and A pipe status detection sensor that detects a virtual plane of the pipe inner surface,
A control device for controlling the movement of the grinding wheel by controlling the grinding wheel feeding means based on the detection information of the pressing force detection sensor and the pipe condition detection sensor.

Since the grindstone is disposed so as to intersect with the underside, there is no change in the grinding resistance at the time of upcut / downcut, and stable grinding can be performed. In addition, since the grindstone side device is clamped by the straight pipe portion of the pipe, troubles such as slippage of the grinding device due to the grinding drag at the time of grinding do not occur.
In addition, since the pressing force is accurately estimated based on the rotation speed of the grinding wheel, the grindability is improved, and high-speed and accurate grinding can be performed. Furthermore, since the feed control of the grindstone is performed by controlling the grindstone feeding means based on the detection information of the pressing force detection sensor and the pipe condition detection sensor, the backwash can be automatically ground to the base material surface.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a pipe inner surface welded portion grinding device according to an embodiment of the present invention.

FIG. 2 is a plan cross-sectional view of a pipe inner surface welding portion grinding device according to an embodiment of the present invention.

FIG. 3 is a system configuration diagram.

FIG. 4 is a flowchart of a main part.

FIG. 5 is a cross-sectional view illustrating a main part configuration of a conventional pipe inner surface welding portion grinding device.

FIG. 6 is a system configuration diagram of the entire pipe inner surface welding portion grinding device.

FIG. 7 is a control flowchart.

[Explanation of symbols]

 21 Virtual Plane 31 Grinding Stone 32 Piping 33 Uranami 34 Grinding Stone Side Device 35 Clamp Mechanism 36 Grinding Stone Drive Motor 37 Torque Tube 38 Drive Side Device 39 Spring Mechanism 42 Grinding Stone Circumferential Driving Motor 44 Grinding Stone Axial Driving Motor 46 Grinding Stone Pressing Motor 48 Pipe inner surface shape measurement sensor 49 Uranami start position 50 Uranami end position 51 Tachogenerator (tacogene) 53 Control computer 58 Base metal surface 71 Grinding machine body

Claims (1)

[Claims] 1. A grindstone-side device having a grindstone disposed so as to intersect a backwash of a welded portion on the inner surface of a pipe, a drive-side device incorporating rotation driving means for driving and rotating the grindstone, and the grindstone-side device An elastic member connection mechanism that connects the and the drive-side device, a clamp device that is provided in the whetstone-side device, and clamps the whetstone-side device with a straight pipe portion of the pipe, and the whetstone in the whetstone-side device. Grinding stone feed means for moving with respect to the backwash, a pressing force detection sensor for detecting a pressing force according to the number of revolutions of the grindstone, and a pipe condition for detecting a start position and an end position of the backwash and a virtual plane of the pipe inner surface. And a control device for controlling the movement of the grindstone by controlling the grindstone feeding means based on the detection information of the pressing force detection sensor and the pipe condition detection sensor. Pipe inner surface welding part grinding machine.