JP2005220742A - Structure of steel pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the structure of a steel pipe joint which quickly allows steel pipes connected to each other without welding or coupling them with screws, when vertically connecting the steel pipes. <P>SOLUTION: A female spline joint 2 is fixed to the top end of a lower steel pipe 1, which is one of two pipes to be joined to each other, and a male spline joint 6 is fixed to the lower end of an upper steel pipe 5, which is the other pipe. These spline joints 2 and 6 are vertically fitted to each other and then fixed by means of a fixing means such as bolts 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a steel pipe joint structure, and is used, for example, to connect steel pipe piles.

  When press-fitting into the ground while rotating the steel pipe pile, in order to reach a predetermined depth, the construction is temporarily stopped during the press-fitting and the steel pipe is connected. In this case, a general method conventionally used is to fix the backing ring to the inner peripheral surface of the upper end of the lower steel pipe by welding, and to fit the lower end of the upper steel pipe to the outer peripheral surface of the backing ring, It is a method of butting the upper end of the steel pipe and welding the butted portion.

  As another method, there may be a method in which a male and female threaded joint is fixed to the ends of the upper and lower steel pipes by welding, and the upper steel pipe is rotated and both the joints are screwed together.

  Since the connection of the steel pipe is performed by interrupting the press-fitting operation as described above, it is necessary to carry out as quickly as possible. However, the conventional connection method has poor workability because it requires welding work and screw connection work. There's a problem.

  Then, this invention makes it a subject to provide the joint structure which can connect a steel pipe rapidly.

  In order to achieve the above object, a steel pipe joint structure according to the present invention has a cylindrical female spline joint fixed to the upper end of a lower steel pipe to be connected, and a cylindrical male pipe at the lower end of the upper steel pipe to be connected. The spline joint is fixed, the above-mentioned spline joints are fitted together in the vertical direction, and the two spline joints are fixed by joint fixing means.

  As said joint fixing means, the following structures can be taken. The first is due to the bolts threaded into the male and female spline joints.

  Second, an inner circumferential groove formed on the inner circumference of the female spline joint, a notch formed at the same height across the splines of the male spline joint so as to face the groove, An arc-shaped stopper fitted in an annular space formed with an inner circumferential groove and a notch facing each other so as to be movable in the circumferential direction, and a stopper operating means. The stopper is formed on the inner surface of the female spline. A short female spline that matches each spline of the joint is formed, and the stopper operating means moves the stopper by at least a half pitch of the short female spline and fixes it in a predetermined position. It is to be. In this case, the stopper has an arc shape with a length equal to or less than one-third of a circle, and at least three stoppers are used in a ring shape. The stopper operating means can be constituted by a long hole provided in the inner peripheral groove portion of the female spline joint, and a screw inserted from the outside into the long hole and screwed into the stopper.

  According to said 2nd joint fixing means, there exists the convenience that a joint part is engaged only by moving a stopper to the circumferential direction. Further, the joint portion can be fixed simply by fastening the screw for each stopper, and the number of screws to be fastened is reduced.

  The third of the joint fixing means includes an inner circumferential groove formed on the inner circumference of the female spline joint, an outer circumferential groove formed on the male spline joint so as to face the inner circumferential groove, and the inner circumferential groove and the outer circumference. An outer circumferential stopper and an inner circumferential stopper fitted in an annular space formed opposite to the groove so as to be movable in the circumferential direction, and an outer circumferential stopper operating means, and the outer circumferential stopper is formed on the inner surface of the outer circumferential stopper. A short female spline that matches each spline of the female spline joint is formed, and the inner peripheral stopper has a short male spline that matches each spline of the male spline joint formed on the outer surface thereof, and The above-mentioned short male and female splines are always fitted, and the stopper operating means has the outer and inner peripheral stoppers at least half the pitch of the female male and female splines. It is dynamic, it is and those to be fixed to a predetermined position.

  According to the third joint fixing means, the load applied to the joint portion can be dispersed and supported by the outer peripheral stopper and the inner peripheral stopper.

  A fourth joint fixing means is provided with the above-described joint fixing means in two upper and lower stages. According to this configuration, the load applied to the joint portion is distributed and supported up and down.

  Fifth of the joint fixing means is an arc-shaped fitting that is installed on the upper end surface of the female spline joint and the upper end surface of the female spline joint and is fitted to the flange so as to be movable in the circumferential direction. The stopper is constituted by a stopper fixing means, and the stopper has a short female spline that matches each spline of the female spline joint on the inner surface thereof. In this case, the stopper has an arc shape with a length of half a circle or less, and at least two stoppers are used in a ring shape.

  The fifth of the joint fixing means is a hook-shaped male spline formed at the upper end of the outer peripheral surface of the female spline joint, and is fitted on the upper end surface of the female spline joint so as to be movable in the circumferential direction on the hook-shaped male spline. The stopper is composed of a combined annular stopper and stopper fixing means. The stopper has an inner surface divided into an upper stage with a small diameter and a lower stage with a large diameter, and an upper female spline that matches the female spline joint on the upper stage and a lower stage with the upper stage. It is the structure formed by forming the lower female spline which corresponds with the said hook-shaped male spline.

  The sixth of the joint fixing means is a cylindrical shape comprising a male screw formed on the outer peripheral surface of the female spline joint, a female screw cylinder screwed with the male screw of the female spline joint, and an inward flange formed on the upper end thereof. The stopper has a female spline that matches each spline of the female spline joint on the inner peripheral surface of the inward flange.

  Any of the fourth to sixth joint fixing means can easily and efficiently perform the stopper mounting operation.

  As described above, according to the present invention, when connection is required during the press-fitting of the steel pipe into the ground, the male and female spline joints fixed in advance to the connection ends of the upper and lower steel pipes are fitted, and the bolt The connection can be completed quickly only by fixing both spline joints with fixing means such as a stopper or the like. In addition, it is possible to exert sufficient strength against torsional loads and pull-out loads.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
The steel pipe joint structure of the first embodiment shown in FIG. 1 to FIG. 3 has an engagement step 3 on the outer diameter surface of the lower end portion of the cylindrical female spline joint 2 on the inner diameter surface of the lower steel pipe 1 to be connected. (See FIG. 2), and the female spline joint 2 is fixed by welding 4 at the fitting portion. Also in the upper steel pipe 5 which is another connection object, the engagement step portion 7 of the upper end outer diameter surface of the cylindrical male spline joint 6 is fitted to the inner diameter surface of the lower end portion, and the male spline is fitted in the fitting portion. The joint 6 is fixed by welding 10.

  In the female spline joint 2, female splines 8 having a predetermined length are provided at a constant pitch in the circumferential direction downward from the upper end of the inner peripheral surface, and the lower ends of the female splines 8 are closed. Further, an appropriate number of a pair of upper and lower countersink recesses 9 are provided on the outer peripheral surface of the female spline joint 2 in the circumferential direction so as to avoid the female spline 8 portion, and through holes 11 are formed at the bottom of each countersink recess 9. Provided.

  Further, the male spline joint 6 is provided with a constant pitch in the circumferential direction so that male splines 12 having a predetermined length can be engaged with the female splines 8 upward from the lower end of the outer peripheral surface thereof. (See FIG. 1). Further, a pair of upper and lower screw holes 13 are provided in positions between the male splines 12 at positions that match the through holes 11 of the female spline joint 2. A bolt 14 as a joint fixing means is screwed into the screw hole 13 from the counter recess 9 through the through hole 11.

  The joint structure of the first embodiment is as described above, and the female spline joint 2 and the male spline joint 6 are respectively fixed to the lower steel pipe 1 and the upper steel pipe 5 in advance. When it is necessary to connect the upper steel pipe 5 during the work of press-fitting the lower steel pipe 1 into the ground, the upper steel pipe 5 is suspended on the upper steel pipe 5 and aligned to connect the male spline joint 6 to the female spline. Fit into the joint 2. Thereafter, as shown in FIGS. 2 and 3, the bolts 14 are screwed to fix the joints 6 and 2 together.

  As shown in FIG. 2, the outer peripheral surface of the female spline joint 2 disposed on the outer periphery of the male spline joint 6 is inside the outer peripheral surface of the upper and lower steel pipes 1 and 5, and the head of the bolt 14 is also recessed. It enters the place 19 and does not protrude outward from the outer peripheral surface of the steel pipes 1 and 5. Even if it sticks out, it is minimized. For this reason, an increase in press-fit resistance can be avoided. Further, the torsional load at the time of press-fitting is supported by the meshing portions of the male and female splines 8 and 12, and the load in the drawing direction is supported by each bolt 14.

  The above-described male and female splines 8 and 12 of the male and female spline joints 2 and 6 have a rectangular cross-sectional shape, but other shapes can be adopted. Examples are shown in FIGS. 4 (a) to 4 (d). (A) and (b) are involute splines, (c) is a gear spline, (d) is a semicircular spline, and (e) is a dovetail spline. These examples can also be used in each embodiment described later.

[Second Embodiment]
Next, the second embodiment shown in FIGS. 5 to 9 will be described. In this case, the configuration in which the female spline joint 2 is fixed to the upper end portion of the lower steel pipe 1 and the male spline joint 6 is fixed to the lower end portion of the upper steel pipe 5 by welding 4 and 10 is the case of the first embodiment. Is the same. What is different is the joint fixing means between the two spline joints 2 and 6. The joint fixing means in this case is as follows.

  That is, an inner peripheral groove 16 deeper than the bottom of the female spline 8 is provided on the inner peripheral surface of the female spline joint 2, and a cut across the upper end of each male spline 12 is provided on the outer peripheral surface of the male spline joint 6. A notch 17 is provided at a constant height. When the male and female spline joints 2 and 6 are fitted together, the inner circumferential groove 16 and the notches 17 face each other to form an annular space. A circular arc stopper 18 of a third circle is fitted in the annular space so as to be movable in the circumferential direction. Actually, after the stopper 18 is inserted into the inner peripheral groove 16 of the female spline joint 2 in advance, the male spline joint 6 is fitted, and each notch 17 faces the stopper 18.

  When the stopper 18 is provided with a short female spline 8 ′ on the inner surface thereof that matches the female spline 8 and is fitted in the inner circumferential groove 16, the stopper 18 moves in the circumferential direction. An alignment state in which the short female spline 8 ′ is aligned with the female spline 8 and an inconsistency state that is shifted by a half pitch in the circumferential direction can be taken.

  In order to move the stopper 18 in the circumferential direction, two elongated holes 19 are provided for each stopper 18 at a position corresponding to the inner circumferential groove 16 on the outer peripheral surface of the female spline joint 2. Then, screws 21 as stopper operating means inserted into the long holes 19 are screwed into the stoppers 18. The stopper 18 can be moved in the circumferential direction by a tool engaged with the screw 21 through the long hole 19. The long hole 19 is formed to a length that allows the stopper 18 to be moved by a half pitch. The screw 21 can fix the stopper 18 at a predetermined position by tightening the screw 21.

  Note that the above-described long hole 19 has the female spline 8 and 8 'at the alignment position when the screw 21 is at the right end (see FIG. 7), and is displaced by a half pitch when it is at the left end (see FIG. 8). The position is selected so as to be in alignment. After positioning in the inconsistent state, the long hole 19 is filled with the filler 30.

  As shown in FIG. 9, the stopper 18 and the inner peripheral groove 16 and the notch 17 that store the stopper 18 may be provided in two upper and lower stages, and the load may be supported in a distributed manner by the joint fixing parts of the upper and lower two stages. .

  Further, as shown in FIG. 10, the stopper 18 may have a dovetail shape in which a portion that fits into the notch 17 extends to the inner peripheral side, and the notch 17 has a cross-sectional shape corresponding to this. It is formed in a shape.

  The joint structure of the second embodiment is as described above. Similarly to the case of the first embodiment, the female spline joint 2 and the male spline joint 6 are previously welded to the lower steel pipe 1 and the upper steel pipe 5 by welding 4 and 10. When the upper steel pipe 5 is connected in advance, the press fitting of the lower steel pipe 1 is temporarily stopped, and three stoppers 18 are annularly fitted from the inner peripheral surface of the female spline joint 2 to the inner peripheral groove 16 thereof. Match. Further, screws 21 are inserted into the long holes 19 and screwed into the stoppers 18. Then, the tool is engaged with the screw 21 and the stopper 18 is moved to the right end of the long hole 19 so that the female splines 8 and 8 'are set in an aligned state. The stopper 18 may be fitted in the inner circumferential groove 16 in advance.

  Next, when the upper steel pipe 5 is suspended, the male spline joint 6 is fitted to the female spline joint 2 in alignment with the stopper 18, and then the stopper 18 is moved counterclockwise by a half pitch to be in an inconsistent state. Therefore, the male and female spline joints 2 and 6 are prevented from coming out in the vertical direction, and the screw 21 is further tightened, whereby the stopper 18 is fixed and the male and male spline joints 2 and 6 are fixed.

[Third Embodiment]
In the case of the third embodiment shown in FIGS. 11 and 12, the female spline joint 2 is fixed to the upper end of the lower steel pipe 1 as in the case of the first and second embodiments, and the lower end of the upper steel pipe 5. The male spline joint 6 is fixed to the part by welding 4 and 10, respectively. What is different is the joint fixing means between the two spline joints 2 and 6. The joint fixing means in this case is as follows.

  That is, a circumferential flange 22 is formed at the upper end of the outer peripheral surface of the female spline joint 2. The stopper 18 is formed in a semicircular shape, and a groove 23 that is movably fitted to the flange 22 is provided on the inner surface thereof. In addition, a short female spline 8 ′ which is placed on the upper end surface of the female spline joint 2 and matches the female spline 8 is formed on the upper portion of the groove 23. An inner peripheral step 20 is provided between the short female spline 8 ′ and the groove 23. A through hole 24 is provided in the groove 23 portion of the stopper 18, and a screw 25 as a stopper operating means is inserted into the through hole 24. The screw 25 is screwed into a screw hole 26 provided in the flange 22 described above.

  The joint structure of the third embodiment is as described above, and the female spline joint 2 and the male spline joint 6 are welded to the lower steel pipe 1 and the upper steel pipe 5 in advance in the same manner as in the above embodiments. In the middle of the press-fitting of the lower steel pipe 1, the press-fitting is temporarily stopped, and the inner peripheral step portions 20 of the two stoppers 18 are placed on the upper end surface of the female spline joint 2 and are annularly formed. In combination, the female spline 8 and the short female spline 8 'are set in an aligned state.

  Next, when the upper steel pipe 5 is suspended, the male spline joint 6 is fitted to the stopper 18 and the female spline joint 2 in the aligned state, and then the stopper 18 is moved to the left or right by a half pitch, the inconsistent state is obtained. Become. As a result, the male and female spline joints 2 and 6 are prevented from coming off in the vertical direction, and the screw 25 is further tightened, whereby the stopper 18 is fixed and the male and male spline joints 2 and 6 are fixed.

[Fourth Embodiment]
Also in the case of the fourth embodiment shown in FIGS. 13 and 14, the female spline joint 2 is fixed to the upper end portion of the lower steel pipe 1 and the male spline joint 6 is attached to the lower end portion of the upper steel pipe 5 in the same manner as the above embodiments. Are fixed by welding 4 and 10, respectively. What is different is the joint fixing means between the two spline joints 2 and 6. The joint fixing means in this case is as follows.

  That is, the short male spline 27 is provided on the outer peripheral surface of the upper end portion of the female spline joint 2. The stopper 18 is formed in an annular shape, its inner peripheral surface is divided into two upper and lower stages, and the upper stage side is formed with a small diameter. A notch 29 in the circumferential direction is provided at the lower upper end of the large-diameter side, and a short female spline 27 ′ that is fitted to the short male spline 27 at the same depth as the notch 29 is provided. The short male spline 27 is fitted in a circumferential annular space formed by the notches 29 and the upper ends of the short female splines 27 'so as to be movable in the circumferential direction.

  Further, a short female spline 8 ′ that matches the female spline 8 of the female spline joint 2 is provided on the upper side of the inner peripheral surface of the stopper 18. Is provided with an inner circumferential stepped portion 20. Further, the stopper 18 is provided with a through hole 24 of a screw 25, and a corresponding screw hole 26 is provided in the short male spline 27.

  The joint structure of the fourth embodiment is as described above, and the female spline joint 2 and the male spline joint 6 are welded to the lower steel pipe 1 and the upper steel pipe 5 in advance in the same manner as in the above embodiments. In the middle of the press-fitting of the lower steel pipe 1, the press-fitting is temporarily stopped, the inner peripheral step 20 of the annular stopper 18 is placed on the upper end of the female spline joint 2, and the short female spline 27 ′ Is fitted to the short male spline 27. In this state, the stopper 18 is moved in the circumferential direction to align the female spline 8 and the short female spline 8 '.

  Next, when the upper steel pipe 5 is suspended, the male spline joint 6 is fitted to the stopper 18 and the female spline joint 2 in the aligned state, and then the stopper 18 is moved to the left or right by a half pitch, the inconsistent state is obtained. Become. As a result, the male and female spline joints 2 and 6 are prevented from coming off in the vertical direction, and the screw 25 is further tightened, whereby the stopper 18 is fixed and the male and male spline joints 2 and 6 are fixed.

[Fifth Embodiment]
In the fifth embodiment shown in FIGS. 15 and 16, the female spline joint 2 is fixed to the upper end portion of the lower steel pipe 1 and the male spline joint 6 is attached to the lower end portion of the upper steel pipe 5 in the same manner as the previous embodiments. It is fixed by welding 4 and 10. A male screw 33 on the outer peripheral surface of the female spline joint 2 is formed.

  In this case, the stopper 18 is formed in an annular shape, and an internal thread 32 is formed on the inner peripheral surface thereof. A short female spline 8 ′ that matches the female spline 8 is provided on the upper part of the female screw 32 via the inner circumferential stepped portion 20.

  The joint structure of the fifth embodiment is as described above, and the female spline joint 2 and the male spline joint 6 are welded to the lower steel pipe 1 and the upper steel pipe 5 in advance in the same manner as in the above embodiments. In the middle of the press-fitting of the lower steel pipe 1, the press-fitting is temporarily stopped, the cylindrical stopper 18 is screwed into the female spline joint 2, and the inner peripheral step portion 20 is connected to the female spline joint 2. The female spline 8 and the short female spline 8 'are aligned while contacting or approaching the upper end surface.

  Next, when the upper steel pipe 5 is suspended, the male spline joint 6 is fitted to the stopper 18 and the female spline joint 2 in the aligned state, and then the stopper 18 is rotated in the circumferential direction by a half pitch, the inconsistent state is obtained. Become. This prevents the male and female spline joints 2 and 6 from coming out in the vertical direction and fixes them.

[Sixth Embodiment]
The sixth embodiment shown in FIGS. 17 to 24 is configured by combining the stopper 18 of each of the above-described embodiments and combining the outer periphery stopper 18a and the inner periphery stopper 18b. The outer peripheral stopper 18a is formed in the shape of a circular arc of one third of the circle, like the stopper 18 described above, and a short female spline 8 ′ that matches the female spline 8 is provided on the inner surface thereof. The inner peripheral stopper 18b is formed in an arc shape having the same central angle as the outer peripheral stopper 18a (see FIG. 18), and a short male spline 12 ′ that matches the male spline 12 is provided on the outer surface thereof. Accordingly, the short male spline 12 'and the short female spline 8' mesh with each other.

  The outer periphery stopper 18a is fitted in the inner peripheral groove 16 formed on the inner peripheral surface of the female spline joint 2 so as to be movable in the circumferential direction, as in the case described above. An outer peripheral groove 17 ′ deeper than the bottom of the male spline 12 is provided on the outer peripheral surface of the male spline joint 6, and an annular space is formed by the outer peripheral groove 17 ′ and the inner peripheral groove 16 facing each other inside and outside. In this annular space, the outer peripheral stopper 18a and the inner peripheral stopper 18b can mesh with each other and move together.

  At the position corresponding to the inner peripheral groove 16, two elongated holes 19 are provided for each outer peripheral stopper 18 a as in the case described above, and screws 21 are screwed into the outer peripheral stoppers 18 a from the elongated holes 19. Combined. The outer peripheral stopper 18a can be moved in the circumferential direction by the tool engaged with the screw 21 described above. Further, the outer peripheral stopper 18a can be fixed at a predetermined position by tightening the screw 21.

  The inner peripheral stopper 18b can move integrally with the outer peripheral stopper 18a. However, the inner peripheral stopper 18b is not fixed only by fixing the outer peripheral stopper 18a as described above. A fixing means unique to the stopper 18b is provided. That is, as shown in FIGS. 18 and 19, two dovetail grooves 34, 34 are provided in the outer peripheral groove 17 'of the male spline joint 6 for each inner peripheral stopper 18b. An inlet 35 is provided at one end of each dovetail 34 (see FIG. 19), a retaining piece 36 is accommodated from the inlet 35, and a bolt 38 inserted from the outside of a bolt hole 37 provided in the inner peripheral stopper 18b. The dovetail groove 34 is screwed into the retaining piece 36 so that the retaining piece 36 is engaged with the dovetail groove 34 at a portion other than the inlet 35 portion. When the bolt 38 is loosened, the inner periphery stopper 18 b can move within the range of the dovetail groove 34 together with the retaining piece 36.

  In order to operate the bolt 38, an insertion hole 39 is provided in the outer peripheral stopper 18 a at a position facing the bolt hole 37. The insertion hole 39 is provided in the 19 opening range.

  The above-described outer peripheral stopper 18a and inner peripheral stopper 18b are combined as described above and moved within the range of the elongated hole 39, and the female splines 8, 8 'and the male splines 12, 12' are aligned vertically. Are shown in FIGS. Further, inconsistency states are shown in FIGS.

  As is apparent from FIG. 23 showing the misalignment state, the convex teeth 8 ′ a of the female spline 8 ′ of the outer periphery stopper 18 a face the lower end surface of the male spline 12 vertically. Further, the convex teeth 12 ′ a of the male spline 12 ′ of the inner peripheral stopper 18 b face the lower end surface of the female spline 8 vertically. Thereby, it turns out that the load of the up-down direction concerning the whole joint part is distributedly supported by radial direction by the outer periphery stopper 18a and the inner periphery stopper 18b.

  In addition, as shown in FIG. 24, a load can be distributedly supported also in the up-down direction by providing the same structure as the above in two steps.

[Seventh Embodiment]
In the seventh embodiment shown in FIGS. 25 and 26, the joint structure is divided into two upper and lower stages, but the upper stage is the same as in the case of the second embodiment described above (see FIGS. 5 to 8), The outer peripheral stopper 18 a engages with the notch 17 of the male spline 12.

  The lower stage employs a structure (see FIGS. 19 and 20) in which the inner peripheral stopper 18b of the fifth embodiment is fitted in the outer peripheral groove 17 'of the male spline joint 6. The male spline 12 ′ of the inner peripheral stopper 18 b is fixed by screwing the bolt 38 inserted through the long hole 19 ′ and screwing it into the retaining piece 36 in the dovetail 34. Moreover, it can be moved in the circumferential direction by loosening the screwing.

  In the joint structure having the above configuration, the outer peripheral stopper 18a and the inner peripheral stopper 18b are independently operated to form the aligned state and the inconsistent state.

[Others]
FIG. 27 is a modification of the case of FIG. 9 described above (second embodiment). A flange 2a is provided on the inner peripheral surface of the lower end portion of the female spline joint 2, and the lower end surface of the male spline joint 6 is provided with the flange portion 2a. I am trying to receive it. Further, a flange portion 6a is provided on the outer peripheral surface of the upper end portion of the male spline joint 6 so as to protrude from the upper end surface of the female spline joint 2, and the flange portion 6a of the lower steel pipe 1, the female spline joint 2, the male spline joint 6 and the upper steel pipe. The outer peripheral surfaces of 5 are the same surface. By comprising in this way, the intensity | strength of an up-down direction and radial direction can be raised. This configuration can be equally applied to the other embodiments described above.

  28 and 29, the lower female spline 8 is omitted from the inner circumferential groove 16 of the female spline joint 2. FIG. Applicable when the torsional load is relatively small. Since the female spline 8 is partially omitted, the processing is simplified and the longitudinal dimension of the female spline joint 2 can be shortened. This modification can also be applied to the above-described embodiments.

Partially omitted exploded perspective view of the first embodiment Partial sectional view of the assembled state Sectional view taken along line III-III in FIG. (A) to (e) Partial sectional view showing an example of a spline Partially omitted exploded perspective view of the second embodiment Partial sectional view of the assembled state Sectional drawing of the alignment state of the VII-VII line of FIG. Sectional view of the mismatched state of line VII-VII in FIG. Partial sectional view of the above-described modification Partial sectional view of another modified example Partially omitted exploded perspective view of the third embodiment Partial sectional view of the assembled state Partially omitted exploded perspective view of the fourth embodiment Partial sectional view of the assembled state Partially omitted exploded perspective view of the fifth embodiment Partial sectional view of the assembled state Partially omitted exploded perspective view of the sixth embodiment Cross-sectional plan view of the assembled state Partially omitted exploded perspective view (A) Partially omitted cross-sectional plan view in the aligned state, (b) Cross-sectional view taken along line bb in FIG. Partially enlarged perspective view of the alignment state same as above (A) Partially omitted cross-sectional plan view of the above inconsistent state, (b) Cross-sectional view taken along line bb in (a), (c) Cross-sectional view taken along line cc in (a). Partially enlarged perspective view of the mismatched state Partial sectional view of the above-described modification Partial sectional view of the seventh embodiment Sectional view along line XX Cross section of the modification Cross section of another modification 28 is a partially exploded perspective view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower steel pipe 2 Female spline joint 2a Collar part 3 Engagement step part 4 Welding 5 Upper steel pipe 6 Male spline joint 6a Collar part 7 Engagement part 8 and 8 'Female spline 9 Countersink recess 10 Weld 11 Through hole 12, 12 'Male spline 13 Screw hole 14 Bolt 16 Inner peripheral groove 17 Notch 17' Outer peripheral groove 18 Stopper 18a Outer peripheral stopper 18b Inner peripheral stopper 19, 19 'Long hole 20 Inner peripheral step 21 Screw 22 鍔 23 Groove 24 Through hole 25 Screw 26 Threaded hole 27 Short male spline 28 Short female spline 29 Notch 30 Filler 32 Female thread 33 Male thread 34 Dovetail groove 35 Inlet 36 Stop piece 37 Bolt hole 38 Bolt 39 Insertion hole

Claims (4)

  A cylindrical female spline joint is fixed to the upper end of the lower steel pipe to be connected, and a cylindrical male spline joint is fixed to the lower end of the upper steel pipe to be connected, and the above spline joints are fitted to each other in the vertical direction. In the steel pipe joint structure in which the two spline joints are fixed by the joint fixing means, the joint fixing means includes a flange formed at the upper end of the outer peripheral surface of the female spline joint, and the female spline. An arc-shaped stopper that is installed on the upper end surface of the joint and is fitted to the collar so as to be movable in the circumferential direction, and a stopper fixing means, and the stopper is formed on the inner surface of the short spline that matches each spline of the female spline joint. A steel pipe joint structure characterized by having a female spline.   The steel pipe joint structure according to claim 1, wherein the stopper is formed in an arc shape having a length equal to or less than a half of a circle, and is used by combining at least two in an annular shape. A cylindrical female spline joint is fixed to the upper end of the lower steel pipe to be connected, and a cylindrical male spline joint is fixed to the lower end of the upper steel pipe to be connected, and the above spline joints are fitted to each other in the vertical direction. In the steel pipe joint structure in which the two spline joints are fixed by a joint fixing means, the joint fixing means includes a hook-shaped male spline formed at the upper end of the outer peripheral surface of the female spline joint, An annular stopper that is installed on the upper end surface of the female spline joint and is fitted to the saddle-shaped male spline so as to be movable in the circumferential direction, and a stopper fixing means. The inner surface of the stopper has a small diameter and a large diameter. An upper female spline that matches the female spline joint is formed on the upper stage, and a lower female spline that matches the saddle-shaped male spline is formed on the lower stage. Joint structure of the steel pipe characterized by comprising Te.   A cylindrical female spline joint is fixed to the upper end of the lower steel pipe to be connected, and a cylindrical male spline joint is fixed to the lower end of the upper steel pipe to be connected, and the above spline joints are fitted to each other in the vertical direction. In the steel pipe joint structure in which the two spline joints are fixed by the joint fixing means, the joint fixing means includes a male screw formed on the outer peripheral surface of the female spline joint and the female spline joint. It is composed of a female screw cylinder that is screwed with a male screw and a cylindrical stopper made of an inward flange formed on the upper end thereof, and the stopper is aligned with each spline of the female spline joint on the inner peripheral surface of the inward flange. A steel pipe joint structure comprising a female spline.

Images