JPS6153992A - Detection of engagement of screw - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for detecting thread engagement in a coupling starter in which a threaded component such as a coupling ring is attached to a threaded seal pipe such as an oil country tubular goods.

[Prior art]

In the above-mentioned coupling starter, in order to automatically and reliably engage the respective threads of the coupling and the pipe, the chuck that grips the coupling is rotated, and the feed rate of the chuck is adjusted to the lead of the screw. When the coupling reaches a predetermined position on the pipe, the coupling is pressed in a direction perpendicular to the pipe axis, automatically and reliably attaching the thread of the coupling to the thread of the pipe. A method has been adopted to match the

Fig. 3 is an explanatory diagram showing the meshing situation, where 4o is the threaded part of the coupling, 41 is the threaded part, 5o is the threaded part of the pipe, 51 is the crest of the thread, 52 is the valley of the thread, and P is the threaded part of the coupling. The direction in which the coupling is pressed, Q is the direction in which the coupling advances, R
is the direction of advancement of the coupling thread relative to the pipe thread. In the figure, the coupling that has reached the predetermined position tK is pressed in the P direction, and the rate of feed is smaller than the screw thread, so the thread 41 of the coupling remains in contact with the thread 51 of the pipe. , will proceed in the R direction. As a result, the ridges 41 of the thread become 41', 41'' and fall into the valley 52 of the thread of the pipe, creating an engagement.
At this time, detecting the establishment of meshing between the coupling and the pipe thread is a particularly necessary technology for automatic operation such as starters, but it has been one of the difficulties in promoting automation because there was no suitable method in the past. .

[Purpose of the invention]

An object of the present invention is to provide a method for detecting the engagement of threads between a coupling and a pipe in order to automatically and reliably engage the respective threads of the coupling and the pipe in a coupling starter. be.

[Summary of the invention]

In order to achieve the above purpose, in a coupling starter screwing device that attaches a threaded part such as a cup nozzle to a threaded pipe, the chuck that grips the coupling is equipped with a meter line on the driving DC motor that feeds the chuck in the direction of the pipe. Alternatively, by interposing a plurality of 70-ting mechanisms in the tube axis direction between the chuck and the spindle, and measuring the change in the DC-like current value or the displacement of the chuck in the 70-ting mechanism. , which attempts to detect the engagement between the camp ring thread and the pipe thread.

[Embodiments of the invention]

1 and 2 show embodiments of the present invention, in which FIG. 1 is a cross-sectional view of a main part of a screwing device for a coupling starter, and FIG. 2 is an enlarged view of an axial floating mechanism.

In the figure, 1 is a chuck equipped with cholera) 1a and is connected to one end of a spindle 4 with a Waldham joint (not shown), 2 is an oil motor that opens and closes the collet 1a via a shaft 6, 5 is a gear 6, An oil motor for rotating the spindle 4 via 7 and the chuck 1 attached to the spindle 4; 8 a plurality of axial floating mechanisms for floating the chuck 1 in the axial direction with respect to the spindle 4; 9 a shaft 10; 12 is a meter relay for measuring the current of the DC motor 9, and 16 is a casing.

Further, as shown in FIG. 2, the axial floating mechanism 8 is composed of a spring 8a, a rod 8b, and a proximity switch 8C, and since the spring 8a is interposed between the chuck 1 and the spindle 4, When the force indicated by the axial arrow is applied to the chuck 1, the chuck 1 can be displaced in the direction of the arrow, and this displacement can be detected by the proximity switch 8C.

Since the main parts of the screwing device are constructed as described above, the chuck 1 holding the coupling B in FIG.
is rotated by the drive of the oil motor 5, and at the same time is sent in the direction of the pipe by the DC motor 9, if the ratio of feed is set smaller than the lead of the screw as described above,
When the coupling thread meshes with the pipe thread,
Since the feed of the coupling becomes equal to the lead of the movement at that point, the coupling and therefore the chuck 1 that grips it will be subjected to tension in the direction of the arrow. Therefore, as the current value of the DC motor changes, a force in the direction of the arrow is applied to the chuck 1, and the axial direction 70-ting mechanism is activated, causing the chuck 1 to be displaced. Therefore, changes in the current value of the DC motor 9 can be detected by the metal relay 12, and displacement of the chuck 1 can be detected by the proximity switch 8C.
This makes it possible to detect whether the coupling thread and the pipe thread are engaged.

Although the above embodiment is an example in which a coupling is attached to a pipe, the present invention can be similarly applied to the case where a general threaded part is attached to a threaded pipe or the like.

〔Effect of the invention〕

As mentioned above, by detecting the change in the current value of the driving DC motor that feeds the coupling, or the axial displacement of the chuck attached to the spindle using an axial floating mechanism, the threading of the coupling and pipe can be detected. Since it is now possible to detect the engagement of the coupling starter, the work of attaching the coupling to the pipe has become reliable.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the main part of the screwing device, FIG. 2 is an enlarged view of the axial floating mechanism, and FIG. 5 is an explanatory view showing the state of engagement of the screws. In the figure, 1 is a chuck, 2 is an oil motor, 6 is a shaft, 4 is a nubindle, 5 is an oil motor, 6.7 is a gear, 8 is an axial direction 70-ting mechanism, 9 is a DC motor, 10 is a screw shaft, 11 12 is a metal relay, and 13 is a casing.

Claims (1)

[Claims] A coupling starter screwing device for attaching a threaded part such as a coupling to a threaded steel pipe includes a DC motor for feeding a chuck that grips the coupling in the direction of the pipe, and a meter relay, or the chuck and the screwing device. A plurality of floating mechanisms capable of floating the chuck in the axial direction are interposed between the spindle of the DC motor, and a current value of the DC motor is changed;
Alternatively, a method for detecting engagement of threads, characterized in that the engagement between the threads of the coupling and the threads of the pipe can be detected by measuring the displacement of the chuck in the axial direction.