JPH0643016B2 - How to fit screws - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement of a screw fitting method in a coupling starter for mounting a threaded component such as a coupling on a threaded pipe.

[Prior art]

For threaded pipes such as oil well pipes and gas pipes, at the time of shipping of the screwed pipe, a coupling (including a screw protector) is used for the screw processed at the end of the pipe body by using a coupling starter. Are being installed.

5 to 7 are views of a conventional coupling starter disclosed in Japanese Patent Publication No. 56-42415. However, in the figure, the grease application device shown in the above publication is omitted.

In the figure, 61 is the coupling starter body, 62
Is a frame fixed on the base floor, 63 is an upper frame,
Reference numeral 64 is a frame up / down cylinder, 65 is a guide, 66 is a runway groove provided in the frame 63 and running in the pipe axis direction, 67
Is a mount with wheels 68 that engage the track groove 66,
Reference numeral 0 is a cylinder connected to the rear of the mounting base 67 via a buffer 71, 72 is a spring fixture fixed to the upper surface of the mounting base 67, and suspending a floating base 74 via a spring 73, 75 Is a vibration motor mounted on the lower surface of the floating table 74, 76 is a pedestal having a pair of V-shaped rollers 77 mounted on the upper portion thereof and fixed on the floating table 74, and 81 is a parallel for each of them. A dovetail groove 79 provided on the floating table 74, which has a roller 78 attached thereto.
The dovetail portion 80 is fitted to, and the screw shaft 82 having both ends fixed to the floating base 74 is rotated to
A pair of bearings that slide in the direction perpendicular to the tube axis, 83 is a hydraulic motor whose output shaft is connected to one rotation shaft of the parallel roller 78 by a universal joint 84, and 86 is erected on the mount 67. A pinch roll 88 is attached to one end, and the other end is a pedestal that pivotally supports the middle of a lever arm 85 to which a rod of an operating cylinder 87 is connected. Further, A is a pipe with a thread, A'is a taper thread portion thereof, B is a coupling, 90 is a coupling supply mechanism provided in the part of the mounting base 67, and 91 is a skid for supporting the pipe A after the tip. is there.

Next, the operation will be described. First, the pipe A has a skid 9 whose stopper position is previously slid according to its diameter.
Stopped on 1. Next, the cylinder 64 is operated to raise the upper frame 63 until the V-shaped roller 77 comes into contact with the pipe A, and the tip of the pipe A is supported by the V-shaped roller 77. On the other hand, in synchronization with this, the coupling supply mechanism 9
0 operates, the coupling B is automatically supplied to the parallel roller 78, and the coupling B and the pipe A are positioned so as to face each other. In general, the pipe A is often slightly bent at the time of manufacturing or handling thereafter. Therefore, when the coupling B is attached to the pipe A in such a state,
Due to the disagreement between the center lines of the two, the fitting is likely to be defective, and an accident such as biting is likely to occur. However, in this apparatus, the V-shaped roller 77 and the parallel roller 78 are provided on the floating table 74, and the floating table 7
4 is a spring 7 arranged on the coupling mount 67
3 is floatingly supported, so that the pipe A is V-shaped roller 7
7, when the spring 73 is actuated, the parallel roller 78 and the coupling B mounted on the spring 73 are also floated by the spring 73 and naturally squeeze the bend of the pipe A. It is possible to automatically align the centers of the taper screw portion A'and the coupling B with each other simply by letting them stand on the parallel roller 78 regardless of the bending of the pipe. Since the parallel roll 78 has a centering adjustment mechanism, the outer diameter of the pipe is changed by rotating the screw shaft 82 and moving the bearing 81 in advance to adjust the opening of the pair of parallel rollers 78. Even so, the above floating is possible.

Subsequently, while the coupling B is being rotated by the hydraulic motor 83, the coupling 70 is approached in the direction of the pipe A by the cylinder 70 to start screwing with the taper screw portion A ′. At this time, the vibration motor 75 operates. By giving a slight vibration to the rotating coupling B, the biting failure at the start of screwing is prevented.

In this conventional device, when the coupling B is screwed onto the threaded portion A'of the pipe A, the coupling B and the pipe A are fixed on the same floating table 74 by a parallel roller 78.
, And the parallel roller 78 is set in advance, the coupling B and the pipe A can be made to coincide with each other in center with respect to their outer diameters. However, in view of the threading conditions of the coupling B and the pipe A, the center of the outer diameter of each of the coupling and the pipe does not exactly coincide with the center of the threaded portion, and the pipe A has a bending after machining. So, when the centerline of the threaded portion of the coupling and the threaded portion of the pipe coincide, this is almost unexpected. If the thread is a triangular thread, even if there is some inconsistency in the center line of the thread between the coupling and the pipe, there is no major problem in the screwing between the coupling and the tube, but in the case of a square thread, Even if the center lines of the threaded portions do not match, or the centers of the threaded portions do not match, the threaded portions interfere and screwing becomes difficult, and the coupling B is slid to the predetermined position of the threaded portion of the pipe A. Not only can it be screwed into the crab, but it may lead to screw scoring and damage to the threads. For this reason, it is necessary to constantly arrange monitoring, which is a major drawback of the conventional device.

[Object of the Invention]

The present invention is made in order to eliminate the drawbacks of the conventional device of the coupling starter in which the threaded pipe as described above is provided with the threaded component such as the coupling. In the coupling starter, the coupling is The purpose of the present invention is to automatically and surely engage the coupling with the thread of the pipe when mounting the pipe on the thread.

[Outline of Invention]

In order to achieve the above object, the present invention provides a coupling starter in which a screw thread formed in a taper portion of an inner circumference of a coupling is screwed to a square screw formed in a taper portion of an outer circumference of an end portion of a steel pipe. In the method of fitting a screw according to, when the end of the threaded portion of the coupling fits into the end of the square screw of the steel pipe and reaches the position in the loose fitting state due to the difference in inner and outer diameters due to the difference in taper between them, While rotating the ring, set the feed rate to a value smaller than the lead of the screw to delay the feed, and when the delayed feed of the coupling is started, the coupling that is in loose fitting with the steel pipe is used as the pipe shaft. The process of forcibly pressing the eccentric force in the direction of the right-angled cross section to make it eccentric, and pressing the threaded end of the coupling into contact with the threaded end of the steel pipe on one side, and the threaded part of the coupling being square When meshed with Release the pressure of the coupling in the direction perpendicular to the tube axis and send the coupling feed rate as the same value as the screw lead, and stop the rotation and feed of the coupling when the final screwing position of the coupling is reached. The process is characterized in that the screw engagement is surely performed.

(Embodiment of the Invention) FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a sectional view of a main part of a screwing device of a coupling starter,
FIG. 2 is an enlarged explanatory view of the engagement of the screws, FIG. 3 is an explanatory view of the operation when the coupling is attached to the pipe, and FIG. 4 is a block diagram of the above operation. The operation will be described below.

In FIG. 1, the coupling B gripped by the collet 1a of the chuck 1 is driven by the oil motor 5 to rotate the gear 6,
7, spindle 4, spindle disk 4a and disk 4a
It can be rotated via the chuck 1 attached to
By driving the DC motor 18, the electric power is sent through the shaft 19 in the direction of the pipe A, that is, in the direction of arrow Q shown in FIG. Coupling B advances in the direction of tube A and becomes coupling B
When the threaded portion B ′ of the screw reaches the point E shown in FIG. 3, the feed rate is reduced to 75% of the lead of the screw, and the coupling B is moved to the arrow P by a hydraulic device (not shown).
When a force of 100 to 120 kg is applied in the direction, as shown in FIG.
Is changed from the one-dot chain line state to the solid line state, and the pipe screw 5
It abuts on the 0 mountain portion 51. Further, since the feed rate of the coupling B is 75% of the lead of the screw as described above, the screw 40 of the coupling B is relative to the screw 50 of the pipe at a speed of Δv in the arrow R direction. Moving. At this time, the thread 41 of the coupling B is the thread 5 of the pipe A.
When the thread crest 41 of the coupling B comes to the position of the thread trough portion 52 of the pipe A while sliding in the R direction with 41 ′ and 41 ″ while being in contact with 1, the thread crest 41 becomes 41 ″. As described above, the thread 40 of the coupling B and the thread 50 of the pipe are smoothly meshed with each other.

An example of the feed rate v of the coupling B (chuck 1) and the relative speed Δv is shown below.

v = 25.4 / 5 crests × 5 rps × 0.75 = 19.1 mm / sec △ v = 25.4 / 5 crests × 5 rps × 0.25 = 6.35 mm / sec Note that the thread crest 41 of the coupling B is in the thread trough 52 of the pipe A. When it falls, that is, when the screw meshes,
Since the screw 40 of the coupling B is pulled by the screw 50 of the pipe A, the current value of the driving DC motor 18 changes. Therefore, if a device for measuring the current value of the driving motor 18 is provided, it is possible to detect when the meshed state is reached.

The work of attaching the coupling B to the pipe A will be described in more detail with reference to FIGS. The coupling B (chuck 1) reaches the point E by fast-forwarding, and then becomes slow-feeding by 75% of the lead of the above-mentioned screw, and the meshing method of the present invention is started. Subsequently, when the meshing start point (point F) obtained by the length measuring device (not shown) in advance is reached, the pressing mechanism (not shown) by the hydraulic cylinder operates, and the coupling B becomes
It is pressed against the pipe in a cross-sectional direction perpendicular to the pipe axis. Proceeding further, from the change of the current value of the drive DC motor 18, the coupling B
When it is confirmed that the screw 40 and the pipe screw 50 have reached the meshing state, the pressure of the coupling B is released, and the feed of the chuck 1 is returned to the same as the lead of the screw.
Subsequently, when the screwing final position H of the coupling B is reached, both the rotation and the feeding of the chuck 1 are stopped, and the screwing operation is completed. Even if the coupling B reaches the meshing end point G, if the meshing state cannot be detected due to the change in the current value of the DC motor 18, the feeding of the chuck 1 is stopped, the rotation is switched to a low speed, and the fixed time T is reached. stand by. Fixed time T
If a meshing condition is detected in the
Is returned to the original state, the coupling B reaches the final position H point, and the screwing device is completed, but if the meshing state is not detected within the set time T, the rotation of the chuck is stopped and an alarm is issued. .

〔The invention's effect〕

As described above, according to the present invention, a coupling starter in which a square screw thread formed on the taper portion of the outer circumference of the end portion of the steel pipe is screwed to a screw thread formed on the taper portion of the inner circumference of the coupling. In the method of fitting a screw according to, when the end of the threaded portion of the coupling fits into the end of the square screw of the steel pipe and reaches the position in the loose fitting state due to the difference in inner and outer diameters due to the difference in taper between them, While rotating the ring, set the feed rate to a value smaller than the lead of the screw for slow feed, and forcibly press the steel pipe and the coupling that are in a loose fitting state in the cross-sectional direction perpendicular to the pipe axis with a constant pressure. Eccentricity, press the screw end of the coupling into contact with the screw end of the steel pipe on one side, and engage the screw part of the coupling with the square screw of the steel pipe. Pressing After releasing, the feed rate of the coupling is the same as the lead of the screw, and when the final screwing position of the coupling is reached, the rotation and feed of the coupling are stopped. From the initial stage of the fitting in which the screw and the screw are in the loose fitting state due to the difference in the inner and outer diameters due to the difference in the taper, the engagement can be induced like the straight screw. Therefore, the coupling and the screw of the steel pipe can be automatically and reliably engaged with each other.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an essential part of a screwing device of a coupling starter showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of screw engagement, and FIG. 3 is a coupling and a pipe. 4 is a block diagram of the screwing operation. 5 to 7 are a front view, a side view and an enlarged view of a conventional device. In the figure, 1 is a chuck, 4 is a spindle, 5 is an oil motor, 6.7 is a gear, 18 is a DC motor, 19 is a screw, 3
Reference numeral 0 is a pipe clamping device, A is a pipe, A'is a threaded portion of the pipe, B is a coupling, B'is a threaded portion thereof, 40 is a screw of the coupling, 41 is a thread of the screw, 50 is a thread of the pipe, 51 is the crest of the screw, 52 is the trough of the screw, P is the pressing direction of the coupling, Q is the feeding direction of the coupling, and R is the direction of relative movement of the pipe of the coupling with respect to the screw of the tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromochi Sakura 17 Urashimaoka, Kanagawa-ku, Yokohama, Kanagawa Prefecture (56) References Japanese Patent Publication No. 51-10919 (JP, B2)

Claims (1)

[Claims] 1. A method of fitting a screw by a coupling starter, wherein a screw thread formed on a taper portion on an inner circumference of a coupling is screwed to a square screw formed on a taper portion on an outer circumference of an end portion of a steel pipe. , When the end of the threaded portion of the coupling fits into the end of the square screw of the steel pipe and reaches the position in which it is loosely fitted due to the difference in inner and outer diameters due to the difference in taper, while rotating the coupling, When the feed rate is set to a value smaller than the lead of the screw and the slow feed is started, and when the slow feed of the coupling is started, the coupling that is loosely fitted to the steel pipe is forced in the cross-sectional direction perpendicular to the pipe axis. Pressing with a constant pressure to make it eccentric, press the threaded end of the coupling into contact with the threaded end of the steel pipe on one side, and if the threaded part of the coupling meshes with the square screw of the steel pipe, Straight with tube axis Releasing the pressure in the cross-sectional direction and sending the coupling feed rate at the same value as the screw lead, and stopping the rotation and feed of the coupling when the final screwing position of the coupling is reached, Fitting method.