JP2011220049A - Mechanical joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint having a structure which, when a steel pipe is intruded into the ground by rotating the steel pipe, reduces the influence of bending stress acting on the steel pipe and prevents the joint from being forced apart during the rotation.SOLUTION: A mechanical joint comprises: a cylindrical outer joint 12 fixed to the bottom end of an upper steel pipe 10; and an inner joint 22 fixed to the upper end of a lower steel pipe 20 via a circular ring body 21. On an inner peripheral surface of the outer joint 12, a plurality of first arc-like rectangular bodies 14 are fixed at equal intervals, and a second arc-like rectangular body 16 is temporarily fixed at a position above the first arc-like rectangular bodies 14. When the outer joint 12 is put on the inner joint 22 and rotated, the first circular rectangle bodies 14 are inserted into a space (horizontal passage) 32 between third and fourth arc-like rectangle bodies 24 and 26 provided on an inner peripheral surface of the inner joint 22, and the second circular rectangle body 16, after being released from the temporary fixing, drops through a space (vertical passage) 30 between the third and fourth circular rectangle bodies 24 and 26 to go across the horizontal passage 32.

Description

  The present invention relates to a mechanical joint for connecting a steel pipe, for example, a lower steel pipe and an upper steel pipe, used in civil engineering construction work.

  Steel pipe piles are often used in civil engineering works to reinforce soft ground. Generally, many welded joints are used as joints for lower steel pipes and upper steel pipes constituting the steel pipe piles, that is, as joints for connecting steel pipes. However, welded joints require a longer time for welding as the thickness and diameter of the steel pipe increase, and the construction machine loss and labor costs are added during that time, and the cost is increased. Although the same strength as the strength is required, the welding operation conditions are greatly affected by the weather, and it is difficult to perform welding uniformly over a long period of time.

  Therefore, the present applicant has first produced a joint with a simple structure that does not depend on welding regardless of the thickness of the steel pipe and the diameter of the steel pipe. We proposed a mechanical joint that can connect the upper and lower steel pipes without welding by simply attaching the connecting means to the steel pipe in the factory and setting it at the construction site (see Patent Document 1).

As shown in FIG. 17, the mechanical joint of the steel pipe according to the previous application welds the short pipe 3 having a plurality of L-shaped locking grooves 4 in the head of the steel pipe lower pile 1, and the upper pile 2. A steel pipe joint joint provided with a locking piece 6 that fits into the locking groove 4 on the inner surface of the lower part thereof, and a wedge plate 7 for locking the locking piece 6 to the locking groove 4. The locking groove 4 includes a vertical groove 4a having an open upper portion and a lateral groove 4b extending in the circumferential direction from the lower portion of the vertical groove 4a. The locking piece 6 can rotate the upper pile 2 from the vertical groove 4a. Accordingly, the wedge plate 7 is placed on the locking piece 6 and detached from the locking piece 6 as the locking piece 6 moves to the horizontal groove 4b. The horizontal groove 4a is dropped to close the horizontal groove 4b, and the locking piece 6 is locked in the horizontal groove 4b to connect and fix the upper and lower piles 1 and 2.
Therefore, steel pipes can be connected without requiring welding at the construction site.
However, it was found that there are still issues that require the following solutions.
That is, in the method of rotationally penetrating the joined steel pipe, a rotational torque is applied to the steel pipe to cause the steel pipe to penetrate into the hard (hard) ground, but when repeating normal rotation and reverse rotation to the steel pipe, as described later, A wedge plate 7 (corresponding to a second arcuate rectangular body) that serves as a wedge may move upward while being deformed, and the wedge engagement may eventually be released.
Moreover, since the locking piece 6 is provided at the lower end of the upper steel pipe itself, the thickness of the upper steel pipe may be less than the thickness required for the joint, and the bending strength of the joint may be insufficient.
In addition, the upper steel pipe is generally very long (for example, 6 m) compared to the joint portion, and the work of providing the joint locking means (arc-shaped rectangular plate) at the end of the factory improves efficiency. It is difficult.

JP 2006-226102 A

  The present invention has been made in order to solve the above-described problems in the conventional mechanical joint, and the purpose of the present invention is to make the steel pipe and the joint part separate from each other in the mechanical joint so that the steel pipe is rotated forward. When the steel pipe penetrates into the ground with alternating rotation and reverse rotation, the shear stress generated in the arcuate plate that becomes a wedge during rotation is reduced, and the arcuate plate is deformed as before It is intended to prevent the joint from coming off and to be obtained at low cost because the structure is simple, and to join the joint in an extremely short time.

The invention of claim 1 comprises a cylindrical outer joint fixed to the end of one steel pipe to be connected, and a cylindrical inner joint fixed to the end of the other steel pipe. A plurality of first arc-shaped plate-like bodies are fixed at equal intervals at the same height on the inner peripheral surface, and the first arc-like plate-like shape is located above the first arc-like plate-like body. A second arcuate plate-like body having the same width as the body or a width narrower than that is temporarily fixed in alignment with the first arcuate plate-like body in the longitudinal direction, and is attached to the outer peripheral surface of the inner joint. The plurality of third arcuate plates are fixed at equal intervals at the same height, and the plurality of fourth arcuate plates are predetermined below the third arcuate plate. Aligned with the third arcuate plate-like body in the vertical direction at intervals and fixed at the same height at equal intervals, between the adjacent edges of the third and fourth arcuate plate-like bodies The second And a longitudinal communication path through which the second arcuate plate-like body can be inserted, and when the inner and outer joints are relatively rotated between the third and fourth arcuate plate-like bodies, the first arcuate shape A horizontal communication path through which the plate-like body can be inserted is formed, and in the engaged state of the inner and outer joints, the second arc-shaped plate-like body is inserted into the horizontal communication path and the temporary fixing is released. The arcuate plate-like body extends so as to be able to contact the third and fourth arc-like plate-like bodies in the longitudinal communication path to block the lateral communication path of the first arc-shaped plate-like body. This is a mechanical joint.
The invention of claim 2 comprises a cylindrical outer joint fixed to the end of one steel pipe to be connected, and a cylindrical inner joint fixed to the end of the other steel pipe. A plurality of third arc-shaped plate-like bodies are fixed at equal intervals at the same height on the inner peripheral surface, and the fourth plurality of arc-shaped plate-like bodies are formed of the third arc-shaped plate-like body. A predetermined interval is provided below, and the third arcuate plate-like body is vertically aligned with the third arcuate plate-like body and fixed at the same height at equal intervals, and between the adjacent third arcuate plate-like bodies. The second arc-shaped plate-like body is temporarily fixed, and a plurality of first arc-shaped plate-like bodies are fixed at equal intervals at the same height on the outer peripheral surface of the inner joint, and the third and second A vertical communication path through which the first arc-shaped plate-like body can be inserted is formed between adjacent edges of the four arc-shaped plate-like bodies, and between the third and fourth arc-shaped plate-like bodies, Inner and outer joints When the relative rotation is performed, a horizontal communication path through which the first arc-shaped plate-like body can be inserted is formed, and in the engaged state of the inner and outer joints, the first arc-shaped plate-like body is inserted into the horizontal communication path, In addition, the second arcuate plate member from which the temporary fixing is released extends in the longitudinal communication path so as to be able to contact the third and fourth arcuate plate members, and the first arcuate plate It is a mechanical joint characterized by closing a lateral communication passage of a cylindrical body.
The invention of claim 3 is a cylindrical inner joint having the same diameter as that of the steel pipe fixed to the end of one steel pipe to be connected, and a diameter larger than the outer diameter of the steel pipe fixed to the end of the other steel pipe. A plurality of first arc-shaped plate-like bodies fixed at equal intervals at the same height on the inner peripheral surface of the outer joint, and the outer periphery of the inner joint. On the surface, a plurality of third arc-shaped plate-like bodies are fixed at equal intervals at the same height, and the plurality of fourth arc-shaped plate-like bodies are below the third arc-shaped plate-like body. At a predetermined interval, the third arcuate plate-like body is fixed at the same height at equal intervals at a position aligned with the third arcuate plate-like body, and adjacent to each of the third and fourth arcuate plate-like bodies. A longitudinal communication path having a space between which the first and second arc-shaped plate-like bodies can be inserted is formed between the edges, and the inner and outer joints are relatively disposed between the third and fourth arc-like plate-like bodies. A horizontal communication path through which the first arc-shaped plate-like body can be inserted when rolled is formed, and in the engaged state of the inner and outer joints, the first arc-shaped plate-like body is inserted into the horizontal communication path, and A second arcuate plate that is inserted into the longitudinal communication path from the outside extends so as to be in contact with the third and fourth arcuate plates, and the first arcuate plate It is a mechanical joint characterized by closing a horizontal communication passage.
The invention of claim 4 is fixed to the end of one steel pipe to be connected and is fixed to the cylindrical inner joint having the same diameter as the steel pipe, and to the end of the other steel pipe, and is larger than the outer diameter of the steel pipe. A plurality of third arcuate plate-like bodies fixed at equal intervals at the same height on the inner peripheral surface of the outer joint. The fourth arcuate plate-like body is positioned at a predetermined interval below the third arcuate plate-like body and is aligned with the third arcuate plate-like body in the vertical direction at the same height at equal intervals. A plurality of first arc-shaped plates are fixed at equal intervals on the outer peripheral surface of the inner joint, and the third and fourth arc-shaped plates are fixed. Between each adjacent edge, a longitudinal communication path having a space through which the first and second arcuate plate-like bodies can be inserted is formed, and the inner and outer joints are provided between the third and fourth arcuate plate-like bodies. A horizontal communication path is formed through which the first arc-shaped plate-like body can be inserted when the relative rotation is performed. When the inner and outer joints are engaged, the first arc-shaped plate-like body is inserted into the horizontal communication path. And the second arcuate plate-like body inserted into the longitudinal communication passage from the outside extends so as to contact the third and fourth arcuate plate-like bodies, and the first arcuate plate It is a mechanical joint characterized by closing a lateral communication passage of a cylindrical body.
The invention according to claim 5 is the mechanical joint according to claim 1 or 2, wherein the inner joint is connected to an end of a steel pipe via a torus. is there.
The invention according to claim 6 is the mechanical joint according to claim 3 or 4, wherein the outer joint is connected to an end portion of the steel pipe via a torus. is there.
The invention of claim 7 is the mechanical joint according to claim 1 or 2, wherein the plurality of second arcuate plate-like bodies are connected to the ring at equal intervals. is there.
According to an eighth aspect of the present invention, in the mechanical joint according to any one of the first to sixth aspects, the first, third, and fourth arc-shaped plate-like bodies are formed with holes in the surface of the plate-like body. The mechanical joint is welded and fixed to an inner or outer joint along the hole.

  According to the present invention, in the mechanical joint, by constituting the steel pipe and the joint part separately, the bending stress acting at the time of rotation when the steel pipe penetrates into the ground while alternately giving forward rotation and reverse rotation is provided. The effect on the steel pipe can be reduced, and the arcuate plate-like body that becomes the wedge is not deformed as in the conventional case and is not detached from the joint. Moreover, the structure is simple and can be obtained at low cost. Bonding can also be performed in a very short time.

It is a perspective view which shows the coupling of the steel pipe of the 1st Embodiment of this invention. It is a perspective view which shows the state which connected the 2nd circular arc-shaped rectangular body mutually. FIG. 3A is a plan view of an arc-shaped rectangular body, and FIG. 3B is a cross-sectional view taken along line cc ′ of FIG. 3A. . It is sectional drawing which shows the welding example of the torus of 1st Embodiment. 5A to 5D are diagrams illustrating the joining order of the mechanical joint according to the first embodiment. It is a plane sectional view of the mechanical joint of a 1st embodiment. It is a longitudinal cross-sectional view of the mechanical coupling of 1st Embodiment. It is a perspective view of the mechanical coupling of 2nd Embodiment. It is a longitudinal cross-sectional view of the joint part of 2nd Embodiment. It is a perspective view of the mechanical coupling of 3rd Embodiment. It is sectional drawing of the mechanical coupling of 3rd Embodiment. It is a perspective view of the mechanical coupling of 4th Embodiment. It is sectional drawing of the mechanical coupling of 4th Embodiment. It is a figure explaining transmission of torque between circular arc-shaped rectangles in each embodiment of the present invention. It is a figure explaining the transmission of the torque between the circular arc-shaped rectangular bodies in the conventional mechanical coupling. It is a figure explaining the state which the 2nd circular-arc-shaped rectangular body in the conventional mechanical coupling deform | transforms and pulls out. It is the disassembled perspective view which showed the joint part of the conventional mechanical joint in the partial cross section.

Hereinafter, embodiments of a joint according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing the vicinity of a joint portion before joining of a mechanical joint of a steel pipe according to a first embodiment of the present invention, and FIG. 2 shows a state in which second arcuate rectangular bodies are connected to each other. FIGS. 3A and 3B are views for explaining fixation by welding of the arc-shaped rectangular body of the mechanical joint of the first embodiment, FIG. 3A is a plan view of the arc-shaped rectangular body, and FIG. -C 'sectional view. FIG. 4 is a cross-sectional view showing a welding example of the torus according to the first embodiment.

  As shown in FIG. 1, the mechanical joint of a steel pipe according to the first embodiment of the present invention includes an upper steel pipe 10 and a cylindrical outer joint 12 integrally connected to the lower end of the upper steel pipe 10 by welding or the like, A first arcuate plate (an arcuate rectangular body in the present embodiment) 14 fixed by welding or the like at the same height near the center in the vertical direction of the inner circumferential surface of the outer joint 12; A second arcuate plate-like body (in this embodiment, an arcuate rectangular body) 16 that is temporarily fixed with a bolt B, for example, and has substantially the same width as the first arcuate rectangular body 14. An annular body 21 integrally connected to the upper end of the lower steel pipe 20, an inner joint 22 integrally connected to the upper surface of the annular body 21, and an outer peripheral surface of the inner joint 22 at the same height and at equal intervals. An upper third arc-shaped plate (an arc-shaped rectangular body in the present embodiment) 24 that is fixedly aligned in the vertical direction, and a lower fourth arc-shaped Shaped body (in the present embodiment arcuate rectangles) consist 26..

The outer joint 12 is a short steel pipe having the same outer diameter as the upper steel pipe 10 and is welded to the lower end portion of the upper steel pipe 10. The thickness of the outer joint 12 may be the same as or thicker than that of the upper steel pipe 10, and can be appropriately determined in design regardless of the thickness of the upper steel pipe 10.
The outer diameter of the first arcuate rectangular body 14 is substantially the same as the inner diameter of the outer joint 12, and the inner diameter is slightly larger than the outer diameter of the inner joint 22.

  The annular body 21 is an extremely short steel ring and has a function of connecting the lower steel pipe 20 and the inner joint 22. The outer diameter of the torus 21 is substantially the same as the outer diameter of the lower steel pipe 20, and the inner diameter is substantially the same as the inner diameter of the inner joint 22.

The same number of third arcuate rectangular bodies 24 as the first arcuate rectangular bodies 14 are already provided on the upper outer surface of the inner joint 22, and the same number of fourth arcuate rectangular bodies 26 are already described on the lower outer surface thereof. As shown, they are aligned and fixed vertically.
The inner diameters of the third and fourth arc-shaped rectangular bodies 24 and 26 are substantially the same as the outer diameter of the inner joint 22, and the thickness and width are substantially the same as those of the first arc-shaped rectangular body 14. Further, the third arc-shaped rectangular body 24 and the fourth arc-shaped rectangular body 26 are arranged such that the vertical interval is slightly larger than the height of the first arc-shaped rectangular body 14.
When the outer joint 12 and the inner joint 22 are aligned, a longitudinal communication path 30 constituted by a gap between the adjacent ends of the third and fourth arc-shaped rectangular bodies 24 and 26 is formed, and In a state where the outer joint 12 and the inner joint 22 are fitted, the lateral communication path 32 formed by a gap between the lower edge of the third arc-shaped rectangular body 24 and the upper edge of the fourth arc-shaped rectangular body 26; The first arcuate rectangular body 14 and the third and fourth arcuate rectangular bodies 24 and 26 are relatively positioned so that the first arcuate rectangular body 14 is aligned in the lateral direction.

The thickness of the second arcuate rectangular body 16 is substantially the same as that of the first arcuate rectangular body 14. The width is set to be slightly smaller than the vertical communication path 30, and when the outer joint 12 is put on (fitted with) the inner joint 22, the vertical connection is made together with the first arc-shaped rectangular plate 12. It can be inserted into the passage 30.
The height of the second arcuate rectangular body 16 is greater than the length from the lower end of the third arcuate rectangular body 24 to the upper end of the fourth arcuate rectangular body 26, In a state in which the inner joint 22 is fitted, the second arcuate rectangular body 16 is arranged so as to be capable of simultaneously contacting the side edges of the third and fourth arcuate plate-like bodies 24 and 26. Torque can be reliably transmitted between the second arcuate rectangular body 16 and the third and fourth arcuate rectangular bodies 24 and 26 when the torque is applied.
Here, the second arc-shaped rectangular body 16 before joining the joint is provided with a screw hole in the outer joint 12 and a bolt B (or a pin) from the outer peripheral surface side of the outer joint. 14 is temporarily fixed on the upper end surface.

FIG. 2 is a perspective view showing a state where the second arc-shaped rectangular bodies are connected to each other.
Since the second arc-shaped rectangular body 16 is not fixed to the outer joint 12, there is a possibility that the position and direction of the second arc-shaped rectangular body 16 may be shifted in an individual state. Therefore, as shown in FIG. 2, it is preferable that the inner peripheral surfaces are connected to each other via a ring 15. The connection between the ring 15 and each second arcuate rectangular body 16 may be fixed by welding, or may be connected by a bolt or a pin. Further, by temporarily fixing with the bolt B, it is possible to prevent the second arcuate rectangular bodies 16 connected to each other from moving during transportation or pile erection.

  The first to fourth arcuate rectangular bodies 14, 16, 24, 26 are obtained by cutting a steel pipe having a predetermined outer diameter and thickness into predetermined dimensions using, for example, a band saw, a laser cutting machine, a gas cutting machine, or the like. Can be formed. On the other hand, the torus 21 is manufactured by cutting a thick steel pipe in a short length or gas cutting a thick plate into a ring shape. The first, third, and fourth arc-shaped rectangular bodies 14, 24, and 26 are fixed to the inner peripheral surface of the outer joint 12 and the outer peripheral surface of the inner joint 22 with a strong adhesive or by welding. Also good.

In the case of welding, welding the end faces of the first, third, and fourth arc-shaped rectangular bodies 14, 24, and 26 smoothly interrupts the weld bead and transmits force to other arc-shaped rectangular bodies adjacent to each other. Not done. Therefore, for example, as shown in FIG. 3A, the plate-like body surfaces of the first, third, and fourth arc-shaped rectangular bodies 14, 24, and 26 are cut into a rectangular shape in plan view, and the inner peripheral surface of the hole formed is used. That is, it is preferable to form a groove on the inner peripheral surface and weld as shown in the cross-sectional view of FIG. 3B.
Note that the shape of the cutout hole may be any shape, and the lower steel pipe 20 and the annular body 21 and the annular body 21 and the inner joint 22 are fixed to either one as shown in FIG. This is done by providing a tip and joining by welding. In that case, the side on which the groove is provided may be appropriately determined in consideration of the welding machine and cost.

Next, the on-site joining procedure of the mechanical joint described above will be described.
5A to 5D are diagrams illustrating the joining order of the mechanical joint according to the first embodiment. Here, in order to make it easy to understand the principle of joining the arcuate rectangular bodies 14, 16, 24, 26 of the mechanical joint, the first to fourth arcuate rectangles except for the outer joint 12 and the inner joint 22 are used. Only the bodies 14, 16, 24 and 26 are displayed.

That is, FIG. 5A is a diagram showing a state in which the upper steel pipe 10 is suspended from the lower steel pipe 20 previously buried in the ground.
In this state, as already described, the first arc-shaped rectangular body 14 and the second arc-shaped rectangular body 16 are vertically arranged on the inner peripheral surface of the outer joint 12 connected to the lower end of the upper steel pipe 10. Arranged in an aligned state. As described above, the first arc-shaped rectangular body 14 is fixed to the inner peripheral surface of the outer joint 12 by welding or the like, and the second arc-shaped rectangular body 16 is inserted from the outer peripheral side of the outer joint 12, for example. A bolt B is temporarily fixed to the upper side of the first arc-shaped rectangular body 14.

FIG. 5B shows a state in which the inner joint 22 at the upper end portion of the lower steel pipe 20 is covered with the outer joint 12 at the lower end portion of the upper steel pipe 10 and the temporary fixing of the second arcuate rectangular body 16 is removed.
In this state, the first and second arcuate rectangular bodies 14 and 16 of the outer joint 12 are arranged in the vertical direction above and below the inner joint 22 in the third and fourth arcuate rectangular bodies 24, 26, the first arcuate rectangular body 14 is inserted between the upper and lower edges of the third and fourth arcuate rectangular bodies 24, 26. It is stopped at position 32.

5C, the upper steel pipe 10 is rotated counterclockwise here from the state of FIG. 5B, and the first arcuate rectangular body 14 is moved between the third and fourth arcuate rectangular bodies 24, 26. The state which is making it approach in the horizontal communication path 32 is shown. In this state, the second arc-shaped rectangular body 16 from which the temporary fixing bolt B is temporarily fixed is going to rotate together with the first arc-shaped rectangular body 14, but as shown in the figure, the third arc-shaped rectangular body 16 is rotated. The contact with the side of the body 24 prevents its rotation. As a result, only the first arc-shaped rectangular body 14 enters the communication path 32 in the direction of the arrow, that is, in the circumferential direction.
When the upper steel pipe 10 is further rotated from the state of FIG. 5C and the first arcuate rectangular body 14 completely enters the lateral communication passage 32 along with this, the second arcuate rectangular body 16 is supported downward. Is lost in the vertical communication passage 30 and the state shown in FIG. 5D is reached.

That is, FIG. 5D shows a state in which the first arcuate rectangular body 14 is completely inserted into the lateral communication path 32 in the circumferential direction, and the second arcuate rectangular body 16 passes through the longitudinal communication path 30 under its own weight. The state where it fell and contacted the torus 21 and stopped was shown.
In this state, the second arc-shaped rectangular body 16 closes the lateral communication passage 32 as shown in the figure. Therefore, even if the upper steel pipe 10 is to be rotated, the side of the first arcuate rectangular body 14 in the lateral communication path 32 comes into contact with the side of the second arcuate rectangular body 16 and the movement thereof is hindered. Therefore, it becomes impossible to rotate.
That is, the second arc-shaped rectangular body 16 functions as a wedge for preventing rotation of the upper and lower steel pipes 10 and 20, and the first arc-shaped rectangular body 14 functions as a wedge for retaining the upper and lower steel pipes, and the inner and outer joints 22. 12, and therefore, the upper steel pipe 10 can be integrally connected to the lower steel pipe 20 buried in the ground so as not to be relatively movable.

FIG. 6 is a cross-sectional view of the mechanical joint in the state of FIG. 5D, and FIG. 7 is a view in which longitudinal sections along ab and bc are respectively combined into one figure.
As illustrated, the first to fourth arcuate rectangular bodies 14, 16, 24, and 26 are wedge-coupled in a state of being engaged with each other. Here, the first to fourth arc-shaped rectangular bodies 14, 16, 24, and 26 are each composed of four sheets, but the number is not limited to that, and any plural number may be used.

According to the mechanical joint for steel pipes of the first embodiment, when the upper steel pipe 10 is rotated by connecting the inner and outer joints 22 and 12, the second arcuate rectangular body 16 which becomes a wedge as will be described later. Is in contact with the third and fourth arcuate rectangular bodies 24, 26 at the opposite edges regardless of the direction of rotation, so that even if subjected to repeated torque, it remains like a conventional mechanical joint. The wedge plate (corresponding to the second arc-shaped rectangular body) does not come out, and stable torque transmission is possible.
Moreover, according to the mechanical joint for steel pipes of this embodiment, since the upper and lower steel pipes 10 and 20 and the inner and outer joints 22 and 12 are configured separately, the thickness of the steel pipe is set in consideration of the excavation torque as in the past. Further, since the inner and outer joints 22 and 12 are extremely short compared to the length of the steel pipe, processing such as fixing the arc-shaped rectangular body in the factory can be easily performed without taking up space. . Therefore, the processing cost can also be reduced.

Next, 2nd Embodiment of the mechanical coupling for steel pipes is described with reference to drawings.
FIG. 8 is a perspective view showing a mechanical joint portion of the second embodiment, and FIG. 9 is a longitudinal sectional view thereof. In FIG. 9, ab and bc represent longitudinal sectional views at the same locations as ab and bc shown in FIG.
As shown in FIG. 8, the mechanical joint of the second embodiment has third and fourth arc-shaped rectangular bodies 24 and 26 formed on the inner peripheral surface of the outer joint 12, and the outer peripheral surface of the inner joint 22. A first arc-shaped rectangular body 14 is formed. In addition, the second arc-shaped rectangular body 16 is temporarily fixed to the inner peripheral surface of the outer joint 12 with, for example, a temporary fixing bolt B as in the first embodiment. Are arranged such that the lower end thereof is the same as or slightly above the lower end of the third arcuate rectangular body 24. Other configurations are the same as those of the first embodiment.

In the second embodiment, in a state where the inner joint 22 at the upper end of the lower steel pipe 20 is covered with the outer joint 12 at the lower end of the upper steel pipe 10 and temporarily fixed, the second arcuate rectangular body 16 of the outer joint 12 is the inner joint. It arrange | positions on the 22 1st circular arc-shaped rectangular body 14. Subsequent operations are the same as those in the first embodiment.
That is, when the temporary fixing of the second arc-shaped rectangular body 16 is removed and the upper steel pipe 10 is rotated, the first arc-shaped rectangular body 14 is moved horizontally between the third and fourth arc-shaped rectangular bodies 24, 26. The second arcuate rectangular body 16 is inserted into the communication path 32 and simultaneously falls in the vertical communication path 30, and the first to fourth arcuate rectangular bodies 14, 16, 24, and 26 are wedge-engaged.
The effect of the mechanical joint of the second embodiment is the same as that of the description joint of the first embodiment.

Next, the description type joint of 3rd Embodiment is demonstrated.
FIG. 10 is a perspective view schematically showing the mechanical joint of the third embodiment, and FIG. 11 is a cross-sectional view thereof. In addition, in FIG. 11, ab and bc represent the longitudinal cross-sectional view in the same location as ab and bc shown in FIG.
In the mechanical joints of Embodiments 1 and 2, the outer diameter of the joint portion is the same as that of the steel pipe body, whereas in the mechanical joint of this embodiment, the outer diameter of the joint portion is larger than that of the steel pipe. is there.

  The outer diameter of the inner joint 22 fixed to the lower end of the upper steel pipe 10 is the same as that of the upper steel pipe 10, and the inner diameter of the outer joint 12 fixed to the upper end of the lower steel pipe 20 via the annular ring 21 is It is larger than the outer diameter of 20. In the space between the outer joint 12 and the inner joint 22, the first, third, and fourth arc-shaped rectangular bodies 14, 24, and 26 are arranged in the same manner as in the first embodiment. Further, in the present embodiment, the second arc-shaped rectangular body 16 is not temporarily fixed to the inner joint 22, and the outer joint 12 is put on the inner joint 22, and then, as in the above embodiments, the upper steel pipe 10 is rotated so that the first arc-shaped rectangular body 14 fixed to the outer joint 12 is fixed between the upper and lower two-stage third and fourth arc-shaped rectangular bodies 24 and 26 fixed to the outer peripheral surface of the inner joint 22. In the inserted state, the second arc-shaped rectangular body 16 is dropped into the vertical communication path 30 formed between the side edges of the third and fourth arc-shaped rectangular bodies 24, 26, whereby the inner and outer joints are wedged. Match. In addition, the mechanical joint for steel pipes of this embodiment is the same as that of Embodiment 1 in other points.

The steel pipe mechanical joint of the present embodiment has the same functions and effects as those of the first and second embodiments, and further has the following functions and effects.
(1) Since the outer diameter of the outer joint portion 12 is larger than that of the steel pipes 10 and 20, the bending strength of the joint portion can be increased. Since the section modulus of the outer joint 12 and the inner joint 22 is increased, the bending strength as a joined joint is also increased.
(2) It is not necessary to temporarily fix the second arcuate rectangular body 16 to the inner joint 22 in advance. After engaging the outer joint 12 and the inner joint 22 to match the circumferential positions of the first arcuate rectangular body 14 and the third and fourth arcuate rectangular bodies 24, 26, the third and fourth The second arcuate rectangular body 16 can be inserted from the outside into the vertical communication path 30 between the arcuate rectangular bodies 24 and 26.
(3) When a steel pipe is used as a temporary casing, the second arc-shaped rectangular body 16 can be pulled out from the joint when it is pulled out after use, so that the joint connection can be released, so that it can be used repeatedly.

FIG. 12 is a perspective view schematically showing the mechanical joint of the fourth embodiment, and FIG. 13 is a cross-sectional view thereof. In FIG. 13, ab and bc represent longitudinal sectional views at the same locations as ab and bc shown in FIG. 6.
The mechanical joint of the present embodiment is such that the outer diameter of the joint portion is made larger than that of the steel pipe, similarly to the mechanical joint of the third embodiment. However, unlike the third embodiment, the first arcuate rectangular body 14 is fixed to the inner joint 12, and the third and fourth arcuate rectangular bodies 24 and 26 are fixed to the outer joint 22. The basic functions and effects of the joint are the same as those of the mechanical joint of the third embodiment.

Finally, the second arcuate rectangular body 16 when torque (torsional shearing force) acts on the joint will be described in comparison with the conventional mechanical joint described in Patent Document 1.
In the mechanical joint of the present embodiment, the first arcuate rectangular body 14 is sandwiched between the upper and lower parts by the third and fourth arcuate rectangular bodies 24 and 26. Then, there is no member corresponding to the third arc-shaped rectangular body 24.

FIG. 14 and FIG. 15 show the second arcuate rectangular body 16 when the torque acts on the joint according to the embodiment of the present invention and the two mechanical joints of the conventional joint described in Patent Document 1, for example. It is a figure which shows the distribution received from the force received from another circular arc-shaped rectangular body, and the shearing force at that time.
When the amount of torque is the same, the total value of the shearing force received by the second arc-shaped rectangular body 16 is the same, but the maximum shearing force is as shown in FIG. 14 in the mechanical joint according to the present embodiment. Since the torque is received by the third and fourth arc-shaped rectangular bodies 24 and 26, it is about half of the mechanical joint described in Patent Document 1 that is received only by the fourth arc-shaped rectangular body 26. For this reason, in the present invention, it can be seen that the second arc-shaped rectangular body 16 is less likely to be deformed than the mechanical joint described in Patent Document 1.

In addition, since the mechanical joint described in Patent Document 1 is not symmetrical in the vertical direction, if the second arcuate rectangular body 16 is deformed, it becomes easy to move in the vertical direction, and if it receives repeated torque, it will come off. Happens.
As a result of the experiment, the mechanical joint according to the present invention stably transmits torque from the upper steel pipe to the lower steel pipe even when subjected to repeated and repeated torque. As shown in the figure, it was greatly deformed, and gradually withdrawn with repetition, and finally transmission of torque became impossible.

According to the mechanical joint for steel pipes according to the present embodiment described above, the outer joint, the inner joint, the torus, and the four types of arc-shaped rectangular bodies constituting the joint have appropriate outer diameters and thicknesses. Since it can be produced by cutting a steel pipe, it requires almost no machining. In addition, a thick steel pipe is not required for manufacturing the inner joint. For this reason, the mechanical coupling for steel pipes can be manufactured at a low cost.
Further, unlike the conventional mechanical joint described in Patent Document 1 in which the locking means is provided on the steel pipe, the joint and the steel pipe main body are separated, that is, an independent configuration. A joint can be easily obtained, and since it is not necessary to attach a projection or the like as a means of the joint to a long steel pipe, the joint can be manufactured efficiently.

In addition, the second arc-shaped rectangular body having a function of transmitting torque between the outer joint and the inner joint is obtained from the lower fourth arc-shaped rectangular body and the upper third arc-shaped rectangular body when torque is applied. In order to receive an equal force, a large shearing force and bending moment do not act.
For this reason, even when forward and reverse repetition torque is applied, the second arcuate rectangular body 16 is not easily deformed, and the second arcuate shape as in the conventional mechanical joint described in Patent Document 1 is not possible. There is no risk that the rectangular body will rise upward and eventually come off.

  DESCRIPTION OF SYMBOLS 10 ... Upper steel pipe, 12 ... Outer joint, 14 ... 1st circular arc-shaped rectangular body, 15 ... Ring, 16 ... 2nd circular arc-shaped rectangular body, 20 ... Lower steel pipe , 21 ... torus, 22 ... inner joint, 24 ... third arcuate rectangular body, 26 ... fourth arcuate rectangular body, 30 ... longitudinal communication path, 32 · ..Horizontal passage.

Claims (8)

It consists of a cylindrical outer joint fixed to the end of one steel pipe to be connected, and a cylindrical inner joint fixed to the end of the other steel pipe,
A plurality of first arc-shaped plate-like bodies are fixed at equal intervals at the same height on the inner peripheral surface of the outer joint, and the first arc-shaped plate-like body is located at a position above the first arc-like plate-like body. A second arcuate plate having the same width as the arcuate plate or narrower than the arcuate plate is temporally aligned with the first arcuate plate and temporarily fixed;
On the outer peripheral surface of the inner joint, a plurality of third arc-shaped plate-like bodies are fixed at equal intervals at the same height, and the plurality of fourth arc-shaped plate-like bodies are formed in a third arc-like shape. Fixed at the same height at equal intervals in the vertical alignment with the third arcuate plate-like body at a predetermined interval below the plate-like body,
A longitudinal communication path through which the first and second arc-shaped plate-like bodies can be inserted is formed between adjacent edges of the third and fourth arc-like plate-like bodies, and the third and fourth circles are formed. When the inner and outer joints are relatively rotated between the arcuate plate-like bodies, a lateral communication passage through which the first arcuate plate-like body can be inserted is formed,
In the engaged state of the inner and outer joints, the first arcuate plate-like body is inserted into the lateral communication passage, and the second arcuate plate-like body, which has been temporarily fixed, is released in the longitudinal communication passage. A mechanical joint that extends so as to be in contact with the third and fourth arc-shaped plate-like bodies and closes the lateral communication passage of the first arc-like plate-like body. It consists of a cylindrical outer joint fixed to the end of one steel pipe to be connected, and a cylindrical inner joint fixed to the end of the other steel pipe,
On the inner peripheral surface of the outer joint, a plurality of third arc-shaped plate-like bodies are fixed at equal intervals at the same height, and the fourth plurality of arc-like plate-like bodies are formed in a third arc-like shape. At a predetermined interval below the plate-shaped body, the third arc-shaped plate-shaped body is vertically aligned with the third arc-shaped plate body and fixed at the same height at equal intervals,
A second arc-shaped plate is temporarily fixed between the adjacent third arc-shaped plates, and a plurality of first arc-shaped plates are the same on the outer peripheral surface of the inner joint. A vertical communication path is formed that is fixed at equal intervals in height, and that allows the first arcuate plate-like body to be inserted between adjacent edges of the third and fourth arcuate plate-like bodies, and When the inner and outer joints are relatively rotated between 3 and the fourth arcuate plate-like body, a lateral communication path through which the first arcuate plate-like body can be inserted is formed,
In the engaged state of the inner and outer joints, the first arcuate plate-like body is inserted into the lateral communication passage, and the second arcuate plate-like body, which has been temporarily fixed, is released in the longitudinal communication passage. A mechanical joint that extends so as to be in contact with the third and fourth arc-shaped plate-like bodies and closes the lateral communication passage of the first arc-like plate-like body. A cylindrical inner joint fixed to the end of one steel pipe to be connected and having the same diameter as the steel pipe, and a cylindrical inner joint fixed to the end of the other steel pipe and having an inner diameter larger than the outer diameter of the steel pipe An outer joint,
A plurality of first arcuate plate-like bodies are fixed at equal intervals at the same height on the inner peripheral surface of the outer joint, and a plurality of third arcuate plate-like bodies are attached to the outer peripheral surface of the inner joint. Are fixed at equal intervals at the same height, and a plurality of fourth arcuate plate-like bodies are spaced apart from the third arcuate plate-like body by a predetermined interval so that the third arcuate plate-like body It is fixed at the same height at equal intervals in a position aligned with the body in the vertical direction,
Longitudinal communication passages are formed between the adjacent edges of the third and fourth arc-shaped plate-like bodies so that the first and second arc-shaped plate-like bodies can be inserted therethrough, and the third and fourth A lateral communication path through which the first arc-shaped plate-shaped body can be inserted when the inner and outer joints are relatively rotated is formed between the arc-shaped plate-shaped bodies,
In the engaged state of the inner and outer joints, the first arcuate plate-like body is inserted into the lateral communication path, and the second arcuate plate-like body inserted from the outside into the longitudinal communication path is the third. And a mechanical joint extending so as to be able to contact the fourth arcuate plate-like body and closing the lateral communication passage of the first arcuate plate-like body. A cylindrical inner joint fixed to the end of one steel pipe to be connected and having the same diameter as the steel pipe, and a cylindrical shape fixed to the end of the other steel pipe and having an inner diameter larger than the outer diameter of the steel pipe And an outer joint,
On the inner peripheral surface of the outer joint, a plurality of third arcuate plate-like bodies are fixed at equal intervals at the same height, and the plurality of fourth arcuate plate-like bodies are formed in a third arcuate shape. At a predetermined interval below the plate-like body, the third arc-like plate-like body is vertically aligned with the third arc-shaped plate body and fixed at the same height at equal intervals,
On the outer peripheral surface of the inner joint, a plurality of first arc-shaped plate-like bodies are fixed at equal intervals at the same height,
Between the adjacent edges of each of the third and fourth arc-shaped plate-like bodies, a longitudinal communication path having a space through which the first and second arc-like plate-like bodies can be inserted is formed, and the third and fourth A horizontal communication passage through which the first arc-shaped plate-like body can be inserted when the inner and outer joints rotate relative to each other is formed between the arc-like plate-like bodies,
In the engaged state of the inner and outer joints, the first arcuate plate-like body is inserted into the lateral communication path, and the second arcuate plate-like body inserted from the outside into the longitudinal communication path is the third. And a mechanical joint extending so as to be able to contact the fourth arcuate plate-like body and closing the lateral communication passage of the first arcuate plate-like body. In the mechanical coupling according to claim 1 or 2,
The inner joint is connected to an end portion of a steel pipe through a torus. In the mechanical joint according to claim 3 or 4,
The mechanical joint is characterized in that the outer joint is connected to an end of a steel pipe via a torus. In the mechanical coupling according to claim 1 or 2,
A plurality of second arcuate plate-like bodies are connected to a ring at equal intervals, and the mechanical joint is characterized in that The mechanical joint according to any one of claims 1 to 6,
The first, third, and fourth arc-shaped plate-like bodies have holes formed in the surfaces of the plate-like bodies, and are welded and fixed to inner or outer joints along the holes. .

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