JP2018123506A - Threaded joint with reverse rotation prevention mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw joint provided with a reverse rotation prevention mechanism which does not increase the size of the screw joint. SOLUTION: A screw joint 1 provided with a reverse rotation prevention mechanism according to the present invention is composed of a screw type male joint 3 and a female joint 7 having an inner surface shoulder portion 5, and is attached to an end portion of a steel pipe 9. 9 is joined, and the reverse rotation prevention mechanism 11 is provided. The reverse rotation prevention mechanism 11 has a first notch 13 formed at the tip of the male joint 3 and an inner surface shoulder portion of the female joint 7. Fitted with the second notch portion 15 formed in 5 and the through hole 19 formed so as to be continuous from the outer peripheral surface of the female joint 7 to the second notch portion 15 and in which the female screw portion 17 is formed. In the completed state, the key groove 21 formed by the first notch 13 and the second notch 15 continuing in the steel pipe axial direction, and the through hole 19 are inserted from the outer peripheral side and screwed into the female thread 17. A screw rod member 25 that functions as a shear key when the male screw portion 23 is formed and reaches the key groove 21 is provided. [Selection diagram] Fig. 1

Description

  The present invention relates to a steel pipe joint that includes a screw-type male joint and a female joint and is attached to an end of a steel pipe such as a steel pipe pile and joins the steel pipe. The present invention relates to a threaded joint including a reverse rotation prevention mechanism that prevents reverse rotation of the joint.

A screw joint consisting of a male joint and a female joint has a high rotational resistance, because if it continues to turn in the direction of the screw, the torque will rise significantly and it will be difficult to tighten further. However, when turning in the opposite direction, the screw is easily removed.
Therefore, when using a threaded joint to join a rotating penetration pile that performs forward rotation and reverse rotation, pins and bolts for preventing reverse rotation as shown in FIGS. 11 to 13 of Patent Document 1 are installed. It is common to do.
In addition, the key hole and screw hole for installing a pin and a bolt are opened according to the position where the male joint and the female joint have been fitted.

Japanese Patent No. 3747594

  However, if you try to place pins and bolts so as not to interfere with the thread of the threaded joint, it is necessary to lengthen the threaded joint by that amount, which may increase the length of the threaded joint itself and increase the cost. was there.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a threaded joint including a reverse rotation preventing mechanism that does not increase the size of the threaded joint.

(1) A threaded joint provided with a reverse rotation prevention mechanism according to the present invention is composed of a threaded male joint and a female joint having an inner shoulder, and is attached to an end of a steel pipe to join the steel pipe. There,
Having a reverse rotation prevention mechanism for preventing reverse rotation of the male joint and the female joint in a fitted state;
The reverse rotation prevention mechanism is
A first notch formed at the tip of the male joint, a second notch formed in the inner shoulder of the female joint, and an outer peripheral surface of the female joint from the outer surface to the second notch. A through-hole formed so as to be continuous and formed with a female screw part, and a key formed by the first notch part and the second notch part being continuous in the steel pipe axial direction in a fitting completed state And a screw rod member that functions as a shear key by reaching the key groove while forming a male screw portion that is inserted into the through hole from the outer peripheral side and screwed into the female screw portion. It is characterized by.

(2) Further, in the above (1), the first notch has a length in the joint axial direction that is 1/2 or more of the diameter of the threaded rod member, and a length in the circumferential direction of the joint. Is longer than the diameter of the threaded rod member.

  The threaded joint provided with the reverse rotation prevention mechanism according to the present invention comprises a threaded male joint and a female joint having an inner shoulder part, and is attached to an end of a steel pipe to join the steel pipe, A reverse rotation prevention mechanism for preventing reverse rotation of the male joint and the female joint in a fitted state, the reverse rotation prevention mechanism comprising: a first notch formed at a tip of the male joint; A second notch formed in the inner shoulder portion of the female joint, and a through-hole formed so as to be continuous from the outer peripheral surface of the female joint to the second notch and having a female screw portion And a keyway formed by the first notch and the second notch being continuous in the direction of the steel pipe in a fitting completed state, and the female screw part inserted into the through hole from the outer peripheral side. A male threaded portion that is screwed onto the key groove and reaching the key groove N by comprising a threaded rod member which serves as a cross key, it is not necessary to increase the threaded joint in order to form a keyway, not be a cost increase.

It is explanatory drawing of the threaded coupling provided with the reverse rotation prevention mechanism of this Embodiment, Comprising: It is a longitudinal cross-sectional view. It is an arrow AA figure of FIG. It is an arrow BB figure of FIG. It is explanatory drawing of the screw coupling provided with the reverse rotation prevention mechanism of this Embodiment, Comprising: It is a longitudinal cross-sectional view of the state which removed the screw rod member. It is a partial enlarged view of the female joint in the screw joint provided with the reverse rotation prevention mechanism of this Embodiment. It is explanatory drawing of the other aspect of the fitting completion state of the screw coupling provided with the reverse rotation prevention mechanism of this Embodiment. It is explanatory drawing of the other aspect of the 1st notch part and 2nd notch part in the threaded coupling provided with the reverse rotation prevention mechanism of this Embodiment.

As shown in FIGS. 1 to 4, the threaded joint 1 provided with the reverse rotation prevention mechanism according to the present embodiment includes a threaded male joint 3 and a female joint 7 having an inner shoulder portion 5. A joint joint that is attached to the end portion and joins the steel pipe 9 and has a reverse rotation prevention mechanism 11 that prevents reverse rotation of the male joint 3 and the female joint 7 when the fitting is completed.
The inner shoulder portion 5 is a ring-shaped stepped portion projecting toward the inner surface at the base of the female joint 7, and the upper surface of the inner shoulder portion is the distal end surface of the male joint 3 when the screw joint 1 is completely fitted. Are arranged opposite to each other.
Hereinafter, the reverse rotation preventing mechanism 11 which is a characteristic part of the present embodiment will be described in detail.

  The reverse rotation prevention mechanism 11 includes a first cutout portion 13 formed at the tip of the male joint 3, a second cutout portion 15 formed in the inner shoulder portion 5 of the female joint 7, and the outer periphery of the female joint 7. A through hole 19 (see FIG. 4) formed so as to be continuous from the surface to the second notch 15 and formed with a female screw portion 17 (see FIG. 4), and the first notch in the fitted state 13 and the second cutout portion 15 are formed in the steel pipe axial direction, and a key groove 21 is formed, and a male screw portion 23 that is inserted into the through hole 19 from the outer peripheral side and is screwed into the female screw portion 17 is formed. And a screw rod member 25 that functions as a shear key by reaching the key groove 21.

<First notch>
The first notch 13 is formed at the tip of the male joint 3 and, as shown in FIG. 2, about half of the screw rod member 25 in the radial direction (upper half in the figure) can be inserted. In the figure, it has a semicircular shape with the lower side opened.
The length of the first notch 13 in the joint axial direction is formed to be 1/2 or more of the diameter of the screw rod member 25 (see FIG. 2). By doing in this way, the area of the bearing surface of the 1st notch part 13 and the screw rod member 25 can be enlarged, the bearing strength of the 1st notch part 13 can be raised, and deformation | transformation can be suppressed small. it can.

The length of the first notch 13 in the joint circumferential direction is longer than the diameter of the screw rod member 25 and longer than the length in the joint axial direction (see FIG. 2).
By doing in this way, the tip of the screw rod member 25 can be inserted into the notch portion even when the positions of the through hole 19 and the first notch portion 13 are shifted in the fitting state.
In the present embodiment, as described above, the first cutout portion 13 is exemplified as a semicircular shape, but the first cutout portion 13 may not necessarily be a semicircular shape, for example, in the joint axial direction. Alternatively, the joint circumferential length may be longer.

<Second notch>
The second cutout portion 15 is formed in the inner shoulder portion 5 of the female joint 7 and, as shown in FIG. 2, is a half in the radial direction (the lower half in the figure) at the portion of the screw rod member 25 where there is no screw. ) Can be inserted, and has a semicircular shape with the upper side opened in the figure.
In addition, the 2nd notch part 15 of this Embodiment is provided so that the inner surface shoulder part 5 of the female joint 7 may be penetrated from the outer side to the inner side.

<Through hole>
As shown in FIGS. 4 and 5, the through-hole 19 is formed so as to be continuous from the outer peripheral surface of the female joint 7 to the second notch portion 15 and is formed with a female screw portion 17.

<Keyway>
The key groove 21 is formed by the first notch portion 13 and the second notch portion 15 being continuous in the steel pipe axial direction in the fitted state, and a plurality of key grooves 21 are provided in the circumferential direction of the screw joint 1. It is preferable. In this Embodiment, as shown in FIG. 3, it is provided in four places in the circumferential direction.
In order to provide a plurality of key grooves 21, a plurality of first notches 13, second notches 15, and through holes 19 (the same number as the key grooves 21) are provided.

  The key groove 21 includes the first notch 13 formed at the tip of the male joint 3 and the second notch 15 formed in the inner shoulder portion 5 of the female joint 7. There is no need to increase the joint length in order to form.

In addition, it is preferable that the 1st notch part 13 and the 2nd notch part 15 are provided so that the foremost wall of a fitting rotation direction may continue in a fitting completion state, as shown in FIG. In this way, even if the male joint 3 tries to move (rotate) relative to the female joint 7 during reverse rotation, the threaded rod member 25 immediately acts as a shear key, causing almost no unnecessary rotation. Because there is no.
Here, the arrow of FIG. 6 has shown the relative rotation direction of the male coupling 3 (upper side in the figure) with respect to the female joint 7 (lower side in the figure).

<Threaded rod member>
The screw rod member 25 functions as a shear key by forming a male screw portion 23 that is inserted into the through hole 19 from the outer peripheral side and screwed into the female screw portion 17 and reaches the key groove 21. That is, the threaded rod member 25 has a male threaded portion 23 formed on the proximal end side and no threaded portion on the distal end side, and is inserted into the through hole 19 when the male joint 3 and the female joint 7 are completely fitted. The threaded rod member 25 is fixed to the female joint 7 by the male threaded portion 23 and the tip end side of the threaded rod member 25 is disposed in the key groove 21 to function as a shear key.

Next, regarding the operation of the reverse rotation prevention mechanism 11 configured as described above, the steel pipe pile to which the female joint 7 is attached is rotated and penetrated into the ground, and the steel pipe pile to which the male joint 3 is attached is joined to the joint pile. An example of the case will be described.
A steel pipe pile to which the male joint 3 is attached is disposed above the female joint 7, and the male joint 3 is rotated with respect to the female joint 7 to fit them together. By making a predetermined number of rotations, the alignment marks coincide with each other, so that the first notch 13 of the male joint 3 and the second notch 15 of the female joint 7 are continuously formed to form the key groove 21. Is done.

When the screw rod member 25 is inserted into the through-hole 19 from the outer peripheral side of the female joint 7 in this state, the tip of the screw rod member 25 reaches the key groove 21 to be in the state shown in FIG. 1 to FIG. 3 or FIG.
At this time, since the first cutout portion 13 has a long shape in the rotation direction, the screw rod member 25 is installed even if the first cutout portion 13 and the second cutout portion 15 are slightly shifted in the rotation direction. be able to.
In addition, since the screw rod member 25 is screw-fixed, no separate fixing means is required.

When all the screw rod members 25 (four in this example) are installed, the spliced steel pipe pile is rotated to penetrate into the ground.
Since the direction of rotational penetration is the same as the direction in which the threaded joint 1 is fitted, regardless of the presence or absence of the threaded rod member 25, the threaded joint 1 can be rotationally penetrated without loosening.

  When the steel pipe pile is reversely rotated during the penetration of the steel pipe pile or when the steel pipe pile is pulled out, the threaded rod member 25 straddles the first notch portion 13 of the male joint 3 and the second notch portion 15 of the female joint 7. Therefore, the male joint 3 and the female joint 7 cannot rotate relative to each other, and reverse rotation is prevented.

  As described above, in the present embodiment, the first notch 13 is formed at the distal end of the male joint 3, and the second notch 15 is formed in the inner shoulder portion 5 of the female joint 7. Since the key groove 21 is formed when the joint 3 and the female joint 7 are completely fitted, it is not necessary to lengthen the threaded joint 1 in order to form the key groove 21, and the cost is not increased.

  In addition, although said 1st notch part 13 and said 2nd notch part 15 are provided so that it may penetrate from the outer side to the inner side, the 1st notch part 13 and the 2nd notch part 15 of this invention are However, it is not always necessary to penetrate, and as shown in FIG. 7, it may be provided so as to be recessed inward from the outer peripheral surface of the male joint 3.

DESCRIPTION OF SYMBOLS 1 Threaded joint 3 Male joint 5 Inner shoulder part 7 Female joint 9 Steel pipe 11 Reverse rotation prevention mechanism 13 1st notch part 15 2nd notch part 17 Female thread part 19 Through-hole 21 Key groove 23 Male thread part 25 Screw rod member

Claims (2)

A screw-type male joint, and a female joint having an inner shoulder portion, which is attached to an end of a steel pipe to join the steel pipe,
Having a reverse rotation prevention mechanism for preventing reverse rotation of the male joint and the female joint in a fitted state;
The reverse rotation prevention mechanism is
A first notch formed at the tip of the male joint, a second notch formed in the inner shoulder of the female joint, and an outer peripheral surface of the female joint from the outer surface to the second notch. A through-hole formed so as to be continuous and formed with a female screw part, and a key formed by the first notch part and the second notch part being continuous in the steel pipe axial direction in a fitting completed state And a screw rod member that functions as a shear key by reaching the key groove while forming a male screw portion that is inserted into the through hole from the outer peripheral side and screwed into the female screw portion. A threaded joint with a reverse rotation prevention mechanism.   The first notch has a length in the joint axial direction that is 1/2 or more of a diameter of the threaded rod member, and a length in the circumferential direction of the joint is longer than the diameter of the threaded rod member. A threaded joint comprising the reverse rotation prevention mechanism according to Item 1.

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