JPH054163B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for stamping a triangle mark for confirming the tightening position of a coupling on a buttress threaded portion of a steel pipe such as an oil country pipe. Prior Art and its Problems For example, buttress screws are generally used for connecting oil country tubular goods. Buttless screws are API (American Petroleum Institute) standard screws, and are standard screws for oil country tubular goods.They have a trapezoidal profile and are characterized by high joint strength. When using the oil country tubular goods mentioned above, it is common to stamp a triangle mark on the buttress threaded portion to indicate the coupling tightening position after threading. This triangle mark has a triangular shape, and when stamping this so-called triangle mark on oil country tubular goods, as shown in Fig. 6, it should be placed at the tightening completion position of the coupling joint 3 that connects both oil country tubular goods 1, 1. Mark so that the bottom of mark 5 is positioned. The marking position of this triangle mark 5 needs to be at a position determined according to the outer diameter of the oil country tubular goods (dimension A shown in Fig. 6) as shown in Table 1. In this case, the reference line of the triangle mark The bottom edge must remain as a stamp mark.

【table】

[Table] However, since there is no specified thread length for buttress screws, the end point of the thread varies, and sometimes ends at dimension A or later. At this time, the bottom of the screw is completely cut in the vicinity of dimension A, but the thread is in an incomplete blackened state. Therefore, in order to leave a triangle mark mark, it is necessary to mark the mark so that the bottom side of the mark does not become the bottom of the screw, that is, the bottom side of the triangle mark is located on the threaded part of the black leather. To explain this based on Figure 7, Figure A
Figure B shows the case where the bottom of the triangle mark is on the screw thread, and Figure B shows the case where the bottom of the triangle mark is on the bottom of the screw. In other words, the area around the specified dimension A is black, but the bottom of the screw 4-1 is cut, so if you engrave it so that the bottom of the triangle mark 5 is in this area, it will appear as shown in Figure B. The bottom of the mark does not remain and the coupling tightening position cannot be confirmed. Therefore, when stamping the triangle mark 5, it must be stamped so that the bottom of the triangle mark is located on the thread 4-2 as shown in Figure A. Conventionally, the above-mentioned triangle mark was stamped by placing the oil country tubular goods on a turning roller and manually rotating the oil country tubular goods while visually positioning and marking the marks. Therefore, there was a problem that it took a lot of effort and time, and work efficiency could not be improved. This invention was made to solve the above-mentioned conventional problems, and aims to propose a device that can automatically engrave a triangle mark at a predetermined position. Composition of the Invention The marking device according to the present invention uses optical means to identify the unevenness of the screw, detects the triangle mark marking position, and rotates the turning roller based on the detection signal to perform positioning in the circumferential direction. This is a device that can engrave a triangle mark so that the bottom of the triangle mark is located on the screw thread. The marking device to which this invention is applied consists of a turning roller for rotationally placing a steel pipe, an end face alignment mechanism for the steel pipe placed on the turning roller, a marking head positioning mechanism in the tube axis direction, and a marking head lifting/lowering mechanism. When the positioning of the head in the tube axis direction is completed, the marking head is raised and lowered to stamp a triangle mark. This invention is a marking device that automates the circumferential positioning of a steel pipe on a turning roller, and its gist is that the above-mentioned device includes a pulse generator provided on the turning roller, an imaging device for a buttress threaded portion of a steel pipe, and the imaging device. A signal processing circuit that binarizes the signal from
The unevenness of the buttress screw is identified based on the binary pattern from the signal processing circuit, the stamping position is calculated from the triangle mark reference bit position, the rotation direction and rotation amount of the steel pipe are calculated, and the turning roller diameter, pipe diameter and A triangle mark embossing position detection circuit that calculates the number of rotational pulses from the amount of rotation, and a turning motor is driven to rotate the steel pipe in a predetermined direction based on the rotational direction rotational pulse number from the triangle mark embossing position detection circuit to generate pulses. a turning motor control circuit that stops the turning motor when the number of pulses of the device reaches the number of rotational pulses;
This enables automatic positioning of steel pipes in the circumferential direction. Hereinafter, this inventive device will be explained in detail based on the drawings. Note that the explanation will be given here by taking oil country tubular goods as an example. FIG. 1 is a side view showing the main body of the apparatus of the present invention, FIG. 2 is a front view of the main body of the above apparatus, and FIG. 3 is a block diagram showing the control system of the above apparatus. That is, the main body of the marking device includes a turning roller 10 for rotating and placing the oil country tubular goods 1, and an end face alignment mechanism 1.
1, a marking head 12, a marking head positioning mechanism 13 in the tube axis direction, and a marking head lifting/lowering mechanism 14. The turning roller 10 is driven by a drive motor 10-1 with a braking device, and has a pulse generator 10-2 for positioning the oil country tubular goods 1 in the circumferential direction. That is, the rotation amount of the turning roller 10 rotated by the drive motor 10-1 is measured by the pulse generator 10-2, and the drive motor 10-1 is stopped when the number of pulses reaches a predetermined number. There is. The end face alignment mechanism 11 has a cylinder 11- on the machine base 9.
A movable stand 11 supported movably in the tube axis direction at 1
-2 has an end face alignment lever 11-3 that comes into contact with the end face of the oil country tubular goods 1 on the turning roller 10, and the end face alignment lever 11-3 moves the movable base 11-2 forward with the cylinder 11-1, and the end face alignment lever 11-3 performs turning. It is designed to stop when it comes into contact with the end face of the oil country tubular goods 1 on the rollers 10. The marking head tube axial direction positioning mechanism 13 supports the marking head holder 12-1 so as to be movable back and forth with a cylinder 13-1 attached to the movable base 11-2, and the marking head holder 12-1 is supported by the cylinder 13-1. The mechanism is such that positioning is performed by moving the tube in the direction of the tube axis. The marking head elevating mechanism 14 is a cylinder rod 14- built in the marking head holder 12-1.
A marking head 12 is attached to the lower part of the marking head 1, and the marking head 12 is raised and lowered by the cylinder. An imaging device (camera) 15 for rotational positioning and a lighting device 16 are attached to the marking head holder 12-1 on both sides of the marking head. As the camera 15, a one-dimensional CCD camera (the field of view is approximately 10 mm equivalent to two screw pitches, and the resolution is 0.05 mm and 200 bits) is used here. Note that the imaging device 15 may be mounted so as to be movable in the tube axis direction.
In that case, the amount of movement can be corrected. Further, in FIG. 3, 16 is a signal processing circuit that binarizes the signal from the imaging device 15, 17 is a triangle mark embossing position detection circuit, 18 is a turning motor control circuit, 19 is a tube diameter setting device, and 20
21 is a stamping head tube axial positioning circuit (for setting dimension A), and 21 is a stamping control circuit. Operation In the above device, first, the pipe diameter setting device 19 selects the dimension A based on the pipe diameter (nominal pipe diameter) of the oil country tubular goods 1, and the marking head positioning circuit 20 uses the marking head pipe axial direction positioning mechanism of the device body. 13 cylinder 13-1 is actuated to determine the position of the marking head 12 from the tube end. Next, the end face alignment mechanism 11
The movable stand 11-2 is advanced in the tube axis direction using the cylinder 11-1, and the end face alignment lever 11-3 is brought into contact with the end face of the oil country tubular goods 1 to align the end faces. When the positioning of the device in the tube axis direction at the marking location is completed, the area around dimension A is illuminated with the lighting fixture 16, and the area is photographed with the imaging device 15. FIG. 4 is an explanatory diagram showing an imaging signal of the buttress threaded portion by the imaging device. In the figure, a indicates the unevenness of the screw thread, b indicates the optical signal, and c indicates the signal after binarization. That is, on the surface of the tube in the vicinity of dimension A illuminated by the illumination, the glossy threaded bottom part 4-1 and the black-skinned threaded part 4-2 can be clearly distinguished depending on the intensity of the light. That is, the glossy screw bottom part 4-1 has a high level of light intensity, and the black-skinned screw thread part 4-2 has a low level of light intensity. By determining the slice level so that the widths of the high and low levels of this optical signal are the same, the binarized signal shown in FIG. c is obtained. FIG. 5 is an explanatory diagram showing binarized high/low patterns and the positions of triangle marks. In other words, rotational positioning of oil country tubular goods involves aligning the center part of the screw thread closest to the triangle mark with the triangle mark. To explain this with reference to FIG. ). There are two pitches worth of high and low patterns within the field of view at the imaging position, so the falling point (a ₁ ,
a ₂ ) and the rising point (b ₁ , b ₂ ), and calculate their midpoints (c ₁ , c ₂ ) using equations (1) and (2) below. c ₁ = a ₁ + b ₁ − _{a 1} /2 … (1) c ₂ = a ₂ + b ₂ − _{a 2} /2 … (2) Next, the triangle mark reference bit (d
Choose the intermediate point (c ₁ or c ₂ ) closest to point ) and select d
The distance (bit) between the point and point c is calculated using the following formula (3). = (c ₁ or c ₂ ) - d...(3) When calculated using the above formula (3), the rotation direction of the OCTG can be determined from the sign (positive or negative), and the rotation direction of the OCTG can be determined using the following formula (4). The quantity x can be calculated. x=/(b-a)×2...(4) On the other hand, if the number of pulses of the pulse generator 10-2 is p pulses/rev, the number of rotation pulses is determined from the turning roller diameter d, pipe diameter D, and rotation amount x. y is below
It is determined by formula (5). y=x・D/d・P…(5) When the rotation amount pulse number in the rotation direction is determined by the above equations (4) and (5), the triangle mark embossing position detection circuit 17 sends the turning motor control circuit 18 to the rotation direction. The rotation amount pulse number y is input, the turning roller drive motor 10-1 is started to rotate the oil country tubular goods, and when the pulse number of the pulse generator 10-2 reaches the predetermined pulse number y, the drive motor 10-1 is started. 1 stops. As a result, the portion having dimension A becomes a threaded portion, and the positioning of the oil country tubular goods in the circumferential direction is completed. Thereafter, an engraving command is sent to the engraving control circuit 21, the engraving head elevating mechanism 14 is operated, and the engraving head 12 is lowered to apply a blow, thereby bringing the bottom of the triangle mark to the buttress thread. It is engraved as shown (at the position shown in FIG. 7A). Effects of the invention As explained above, according to this inventive device,
Since the positioning of the steel pipe can be performed automatically and accurately when marking the triangle mark after cutting the buttress thread of the steel pipe, the positioning work can be simplified and speeded up, and the work efficiency can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the main body of the apparatus according to the present invention. FIG. 2 is a front view of the main body of the device.
FIG. 3 is a block diagram showing the control system of the same device. FIG. 4 is an explanatory diagram showing an imaging signal of the buttress screw portion of the same device. Figure 5 shows 2 of the same device.
It is an explanatory view showing a value pattern and a triangle mark position. FIG. 6 is a plan view showing a connecting portion of oil country tubular goods. FIG. 7 is an explanatory diagram showing the engraving position of the triangle mark. 1... Oil country pipe, 9... Machine base, 10... Turning roller, 10-1... Drive motor, 10-2...
...Pulse generator, 11... End face alignment mechanism, 12...
...Marking head, 13...Marking head tube axial positioning mechanism, 14...Marking head lifting mechanism, 15...
...Imaging device, 16... Signal processing circuit, 17... Triangle mark embossing position detection circuit, 18...
Turning motor control circuit, 19...pipe diameter setting device, 20...engraving head tube axial positioning circuit,
21... Stamp control circuit.

Claims (1)

[Claims] 1 Consists of a turning roller that rotates and places the steel pipe, an end face alignment mechanism for the steel pipe placed on the turning roller, a mechanism for positioning the marking head in the tube axis direction, and a marking head lifting mechanism. An automatic marking device that stamps a triangle mark by raising and lowering a head, includes a pulse generator provided on a turning roller, an imaging device for a buttress thread of a steel pipe, and a signal processing circuit that binarizes a signal from the imaging device.
The unevenness of the buttress screw is identified based on the binary pattern from the signal processing circuit, the stamping position is calculated from the triangle mark reference bit position, the rotation direction and rotation amount of the steel pipe are calculated, and the turning roller diameter, pipe diameter and A triangle mark embossing position detection circuit that calculates the number of rotational pulses from the amount of rotation, and a turning motor is driven to rotate the steel pipe in a predetermined direction based on the rotational direction rotational pulse number from the triangle mark embossing position detection circuit to generate pulses. An automatic marking device for steel pipes, comprising a turning motor control circuit that stops the turning motor when the number of pulses of the tool reaches the number of rotational pulses.