JP6858513B2 - Steel pipe connection mechanism - Google Patents

Description

In the present invention, a box joint is provided on one of the steel pipe ends facing each other in the direction of the steel pipe axis, and a pin joint that can be fitted in the box joint on the other side of the steel pipe ends facing each other. Is provided, an inward groove portion along the circumferential direction is formed on the inner peripheral surface portion of the box joint, and an outward groove portion along the circumferential direction forms an outer peripheral surface portion of the pin joint on the outer peripheral surface portion of the pin joint. A plurality of dividing key members are formed so as to face the inward groove portion in a state of being fitted to the inner peripheral surface portion of the box joint, and a plurality of split key members are provided around the steel pipe axis in the inner circumference of the box joint in the inward groove portion. Each of the split key members in the accommodation position is provided in a state where the outer peripheral surface portion of the pin joint is fitted to the inner peripheral surface portion of the box joint. The present invention relates to a steel pipe connecting mechanism capable of pushing into a straddling position straddling the facing groove portion and the outward groove portion and connecting the steel pipe end portions facing each other of the adjacent steel pipes in a retaining state.

The steel pipe is used for various purposes such as building support piles, steel pipe piles, steel pipe sheet piles, landslide prevention piles, earth retaining column piles, and structural columns. In such applications, steel pipes are required to have a length of, for example, several tens of meters in order to drive into a support layer which is a hard ground under a soft ground.

Steel pipes are manufactured at the factory and transported from the factory to the site. At that time, there is a limit to the length that can be transported due to the convenience of transportation means, for example, road vehicles such as trucks.
Therefore, if a steel pipe with a length of several tens of meters is required, the factory manufactures multiple steel pipes with a length of several meters, transports them by truck, etc., and press-fits the brought-in steel pipe with a hydraulic hammer. While driving into the ground with a machine, a rotary press-fitting machine, etc., they are sequentially connected by a steel pipe connecting mechanism.

As a steel pipe connecting mechanism, as shown in Patent Document 1, a state in which an outer peripheral surface portion of a pin joint provided at the other steel pipe end portion is fitted to an inner peripheral surface portion of a box joint provided at one steel pipe end portion. Then, for each of the split key members housed in the accommodating position that is inserted into the inward groove portion provided on the inner peripheral surface portion of the box joint from the inner peripheral surface portion of the box joint, the set bolt that is the key operating member is used. By operating, it is pushed into a straddling position straddling the inward groove portion provided on the inner peripheral surface portion of the box joint and the outward groove portion provided on the outer peripheral surface portion of the pin joint, and the adjacent steel pipes face each other. An example is a configuration in which steel pipe ends are provided so as to be able to be connected to each other in a retaining state. The set bolt is provided on one end side thereof with a right-handed screw portion for screwing into each of a plurality of screw holes provided at intervals in the circumferential direction from the outer periphery of the box joint, and is provided on the other end side of each division key member. It is equipped with a left-handed screw that is screwed with a left-handed screw (reverse screw).

Before connecting the end portions of the steel pipes, the split key member is assembled in the inward groove portion provided on the inner peripheral surface portion of the box joint at a storage position that is inserted into the inner peripheral surface portion of the box joint.
When connecting adjacent steel pipe ends facing each other, the set bolt is placed in one direction (positive direction, from the outer peripheral surface side of the box joint) with the outer peripheral surface of the pin joint fitted to the inner peripheral surface of the box joint. By rotating in the right direction), the split key member is screwed from the inward groove side to the outward groove side, and the split key member in the accommodation position is pushed into the straddling position.
As a result, the ends of the steel pipes are connected to each other in a retaining state.
If it becomes necessary to release the retaining state of the split key member, rotate the key operation member from the outer peripheral surface side of the box joint in the other direction (reverse direction, left direction) to release the split key member. It is screwed from the outward groove side to the inward groove side, and the split key member at the straddling position is pulled back to the accommodation position.

Japanese Unexamined Patent Publication No. 2000-31987

As described above, steel pipes are used for various purposes such as building support piles, steel pipe piles, steel pipe sheet piles, landslide prevention piles, earth retaining column piles, and structural columns. In particular, a strong load acts on each split key member from the inward peripheral groove and the outward peripheral groove in the longitudinal direction and the circumferential direction of both steel pipes.

Since the inward peripheral groove and the outward peripheral groove have a slight clearance with respect to the split key member, the split key member has a longitudinal direction or a circumferential direction in the inward peripheral groove and the outward peripheral groove due to the load. Will be moved to.
At this time, the set bolt moves like scooping a screw hole of a split key member or a screw hole of a box joint.
Due to this movement, the screw between the set bolt and each screw hole may be loosened, the set bolt itself may be damaged, or each screw hole may be damaged.

If the set bolt is loosened or damaged, the split key member will move from the straddling position to the accommodating position, and it will not be possible to maintain the regulation of relative movement of both steel pipes in the longitudinal direction.
Further, if the screw hole of the set bolt is damaged, the set bolt cannot rotate, and the connected steel pipe ends cannot be separated from each other.

The present invention has been made in view of the above circumstances, and the mechanism for holding the split key member in the accommodation position and the mechanism for maintaining the split key member in the straddling position are physically separated from each other. It is an object of the present invention to provide a steel pipe connecting mechanism capable of solving the above problems.

A feature of the connecting structure according to the present invention is that a box joint is provided on one of the steel pipe ends facing each other in the direction of the steel pipe axis, and in the box joint on the other side of the steel pipe ends facing each other. A matable pin joint is provided, an inward groove portion along the circumferential direction is formed on the inner peripheral surface portion of the box joint, and an outward groove portion along the circumferential direction is formed on the outer peripheral surface portion of the pin joint. The outer peripheral surface portion of the pin joint is formed so as to face the inward groove portion in a state of being fitted to the inner peripheral surface portion of the box joint, and a plurality of split key members are formed in the inward groove portion around the steel pipe axis. The split key member at the accommodation position is provided so as to be accommodating in an accommodating position that is recessed from the inner peripheral surface portion of the box joint, and the outer peripheral surface portion of the pin joint is fitted to the inner peripheral surface portion of the box joint. It is a steel pipe connecting mechanism that can push each of the above into a straddling position straddling the inward groove portion and the outward groove portion, and connect the steel pipe end portions facing each other of the adjacent steel pipes in a retaining state. The box joint is provided with through holes for communicating with the inward groove portion from the outer peripheral surface portion of the box joint for each of the split key members, and the through holes are provided with the outer periphery of the pin joint. When the surface portion is fitted to the inner peripheral surface portion of the box joint, a maintenance mechanism that abuts on the surface of the split key member and maintains the split key member at the straddling position can be attached. When the split key member is maintained at the straddling position by the maintenance mechanism, the split key member is in a non-locking state with respect to the through hole in the radial direction of the through hole.

By attaching the maintenance mechanism to the through hole, the split key member can be maintained at the straddling position, so that the fitting of the steel pipe end portions is connected in a retaining state.
At this time, since the split key member is not locked with respect to the through hole in the radial direction of the through hole, the split key member is placed in the inward peripheral groove and the outward peripheral groove due to the load acting on the split key member. Even if it is moved in the longitudinal direction or the circumferential direction, the dividing key member and the through hole do not interfere with each other.
When it becomes necessary to release the retaining state of the steel pipe ends by the split key member, the maintenance mechanism is removed from the through hole to release the maintenance of the straddling position of the split key member.
When the maintenance mechanism is not attached to the through hole, the split key member at the accommodation position can be pushed into the straddle position from the outer peripheral surface side of the box joint through the through hole to accommodate the division key member at the straddle position. It can also be pulled back to the position.

In the present invention, when the maintenance mechanism maintains the split key member at the straddle position, a dropout prevention mechanism for preventing the maintenance mechanism from falling out of the through hole is provided in the through hole. It is preferable that the device is freely attached to the device.

Since the dropout prevention mechanism prevents the maintenance mechanism attached to the through hole from falling off, it is possible to avoid the possibility that the retaining state of the steel pipe ends is unintentionally released.

In the present invention, the through hole is provided with a female screw on the inner peripheral surface thereof, and the maintenance mechanism can be screwed into the female screw provided on the inner peripheral surface of the through hole and the female screw. It is preferable that the member is composed of a male screw member provided with a male screw.

The maintenance mechanism is realized by a simple configuration of a female screw provided on the inner peripheral surface of the through hole and a male screw member provided with a male screw that can be screwed into the female screw.

In the present invention, when the outer peripheral surface portion of the pin joint is not fitted to the inner peripheral surface portion of the box joint, the split key member is inserted from the outer peripheral surface portion side of the box joint through the through hole. It is preferable that a holding mechanism capable of holding the accommodation position is provided.

The holding mechanism can hold the split key member in the accommodating position from the outer peripheral surface side of the box joint through the through hole when the outer peripheral surface portion of the pin joint is not fitted to the inner peripheral surface portion of the box joint. is there. For example, in a factory or the like, the split key member can be assembled in advance at the accommodation position and transported to the site in that state. Further, in the steel pipe connecting work, the holding of the split key member at the accommodating position can be released from the outer peripheral surface side of the box joint only after the steel pipe ends are fitted to each other. You will be able to save time. When the split key member is not held in the accommodation position by the holding mechanism, or when the division key member is not held in the straddling position by the maintenance mechanism, the division key member can be freely moved between the accommodation position and the straddling position. It can be pushed in or pulled back.

In the present invention, the holding mechanism has a rod-shaped member or a string-shaped member whose one end is connected to the split key member and whose other end is freely insertable into the through hole, and the rod-shaped member or the string-shaped member. It is preferable that the other end side is provided with a gripping member that can be gripped from the outer peripheral surface side of the box joint.

With a simple configuration, the other end side of the rod-shaped member or string-shaped member, whose one end side is connected to the split key member housed in the inward groove portion of the box joint, is gripped from the outer peripheral surface side of the box joint by the gripping member. The split key member can be easily held in the accommodation position.

In the present invention, it is preferable that the male screw member is provided with a fitting portion into which a tool for screwing the male screw member can be fitted.

The male screw member can be easily screwed by the tool fitted in the fitting portion.

In the present invention, the fitting portion is formed by an opening formed at the center of the screwing axis of the male screw member, and the male screw member maintains the split key member at the straddling position. At a certain time, it is preferable that the rod-shaped member or the string-shaped member can be freely inserted into the opening.

Since the rod-shaped member or the string-shaped member can be freely inserted into the opening of the male screw member, the rod-shaped member or the string-shaped member can be inserted even when the split key member is maintained at the straddling position. , Can be left attached to the split key member.

In the present invention, it is preferable that the male screw member also functions as an operation mechanism capable of pushing the split key member at the accommodation position into the straddling position.

From the outer peripheral surface of the box joint, the split key member at the accommodation position can be pushed into the straddling position by the male screw member, and the split key member can be maintained at the straddling position as it is.

In the present invention, the rod-shaped member also functions as an operation mechanism capable of pushing and pulling the split key member from the outer peripheral surface side of the box joint through the through hole to the accommodation position and the straddling position. Then, it is preferable.

The split key member can be easily moved to the straddling position or the accommodating position by pushing and pulling the split key member from the outer peripheral surface portion of the box joint by the rod-shaped member passing through the through hole.

In the present invention, it is preferable that the string-shaped member also functions as an operation mechanism capable of pulling back the split key member at the straddling position to the accommodating position through the through hole from the outer peripheral surface side of the box joint.

By pulling the string-shaped member passing through the through hole from the outer peripheral surface portion of the box joint, the split key member can be pulled back and the split key member can be easily moved from the straddling position to the accommodation position.

Partial cross-sectional side view showing the connected state of steel pipes by the steel pipe connecting mechanism Side sectional view of the main part of the steel pipe connecting mechanism Enlarged sectional view of the main part of the steel pipe connecting mechanism Enlarged plan sectional view of the main part of the steel pipe connecting mechanism Side sectional view of steel pipe connecting mechanism Side sectional view of steel pipe connecting mechanism Side sectional view of steel pipe connecting mechanism Enlarged sectional view of the main part of the steel pipe connecting mechanism Side sectional view of steel pipe connecting mechanism Enlarged sectional view of the main part of the steel pipe connecting mechanism Planosection of the main part of the steel pipe connecting mechanism Enlarged plan sectional view of the main part of the steel pipe connecting mechanism Enlarged sectional view of the main part of the steel pipe connecting mechanism Enlarged sectional view of the main part of the steel pipe connecting mechanism Explanatory drawing of gripping member

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows steel pipe piles 1 (1A, 1B) used in the middle digging method in which the material is rotationally press-fitted into the ground while excavating with an auger.

In the steel pipe pile 1 (1A, 1B), a cylindrical box joint 3 is welded and connected to one pipe end of a steel pipe 2 such as a cylindrical spiral steel pipe, and a box joint is connected to the other pipe end of the steel pipe 2. A small-diameter cylindrical pin joint 4 that can be fitted to 3 is welded and connected to form a cylindrical shape having a substantially constant outer diameter over the entire length.

The steel pipe pile 1 (1A, 1B) is buried in the ground with the pin joint 4 facing upward. The pipe ends of the steel pipe piles 1 (1A, 1B) adjacent to each other in the axial X direction of the steel pipe pile 1 are connected to each other by the steel pipe connecting mechanism according to the present invention in a retaining state and a rotation preventing state. To.

The steel pipe connecting mechanism includes a box joint 3, a pin joint 4, a load transmission key 5, and a rotation suppression key 6. Hereinafter, they will be described in order.

First, the box joint 3 will be described.
As shown in FIG. 2, in the box joint 3, a ridge 7 is formed at the lower end thereof, and a plurality of tubular side notch recesses 8 are provided at intervals in the circumferential direction, and the box joint 3 is provided on the upper portion of the inner peripheral surface portion 9. A peripheral groove 10 is formed.
Further, on the inner peripheral surface portion 9, a plurality of inward groove portions 11 along the circumferential direction (two in the present embodiment) are formed in a series of annular shapes around the axial center X in a cross-sectional view along the respective axial center X. It is done.
As shown in FIG. 4, the groove depth D1 of each inward groove portion 11 is formed to be larger than the thickness t along the radial direction of the steel pipe pile 1 (1A, 1B) of the split key member 5A described later. As a result, the entire split key member 5A can be accommodated in the accommodating position in which the entire inner peripheral surface portion 9 is inserted.

Next, the pin joint 4 will be described.
As shown in FIG. 2, the pin joint 4 has a shaft such that the length of the outer peripheral surface portion 12 in the axial X direction is the same as the inner peripheral surface portion 9 of the box joint 3 and is in close contact with the inner peripheral surface portion 9. It is formed with a constant outer diameter along the core X.
On the lower end side of the pin joint 4, when the box joint 3 is fitted, each of the positions facing the cylinder side notch recess 8 provided in the box joint 3 has the same depth as the cylinder side notch recess 8. Shaft-side notch recesses 13 having a required length are provided at the top and bottom. A screw hole 14 is provided in the central portion of each shaft-side notch recess 13.
On the lower end side of the pin joint 4, between the notch recesses 13 on each shaft side, a peripheral groove 15 into which the ridge 7 included in the box joint 3 can be fitted is formed.
At the tip of the pin joint 4, a ridge 16 that can be fitted into the peripheral groove 10 included in the box joint 3 is provided.
When the outer peripheral surface portion 12 has a plurality of (two in the present embodiment) outward groove portions 17 along the circumferential direction in cross-sectional view along the axis X, and the outer peripheral surface portion 12 is fitted to the inner peripheral surface portion 9. In addition, a series of annular rings are formed around the axis X so as to face the inward groove portion 11.

Next, the load transmission key 5 will be described.
The load transmission key 5 is a member for connecting the box joint 3 and the pin joint 4 in a retaining state, and is composed of a plurality of (six in this embodiment) split key members 5A around the axis X. is there.
As shown in FIGS. 4 and 12, each of the divided key members 5A is a long body made of steel having a rectangular cross-sectional shape, and the inner peripheral surface of the key facing the groove bottom surface 17A side of the outward groove portion 17 is formed. The outward groove portion 17 is formed in a shape curved in an arc shape so as to have substantially the same curvature as the groove bottom surface 17A.

Each of the load transmission keys 5 housed in the inward groove portion 11 at the accommodating position inside the inner peripheral surface portion 9 is pushed from the outer peripheral surface side of the box joint 3 to the outward groove portion 17 side to be freely operated. As a result, by pushing into the straddling position straddling the inward groove portion 11 and the outward groove portion 17 facing each other, the fitting is fitted into the straddling position straddling the inward groove portion 11 and the outward groove portion 17 and fitted to each other. The box joint 3 and the pin joint 4 are connected in a retaining state.

As shown in FIG. 4, the groove depth D2 of the outward groove portion 17 is formed so as to be substantially half of the thickness t along the radial direction of the steel pipe pile 1 (1A, 1B) of the split key member 5A. There is.
As a result, as shown in FIG. 12, when the inner peripheral surface of each division key member 5A is pushed into the straddling position in contact with the groove bottom surface 17A of the outward groove portion 17 over the entire circumference, each division key member 5A is pushed into the straddling position. The overlapping area of the member 5A with respect to the inward groove portion 11 in the axial center X direction and the overlapping area of the outward groove portion 17 with respect to the axial center X direction are substantially the same area.

Next, the rotation suppression key 6 will be described.
The rotation suppression key 6 is a member for connecting the box joint 3 and the pin joint 4 in a non-rotating state, and is formed in a key arrangement portion composed of a cylinder-side notch recess 8 and a shaft-side notch recess 13 facing each other. It is formed in a corresponding shape.
As shown in FIG. 1, the rotation suppression key 6 is on the shaft side facing each cylinder-side notch recess 8 and its cylinder-side notch recess 8 when the box joint 3 and the pin joint 4 are fitted. By straddling the notch recess 13, the relative rotation of the steel pipe piles 1 (1A, 1B) connected to each other is prevented. The rotation restraint key 6 is fixed to the pin joint 4 side with the fixing bolt 19.

The operation mechanism 18 will be described.
As shown in FIGS. 1 to 4, in the box joint 3, through holes 21 having a circular cross section communicating from the outer peripheral surface 20 to the inside of the inward groove portion 11 are provided in the circumferential direction corresponding to each of the division key members 5A. It is provided at a plurality of locations (6 locations in the present embodiment) at intervals.

A rod-shaped member 22 is projected at a central position in the longitudinal direction and the height direction of the split key member 5A.
In the present embodiment, the rod-shaped member 22 is composed of a threaded rod, and one end side of the rod-shaped member 22 is screwed into a female screw formed on the split key member 5A.
Since the diameter of the rod-shaped member 22 is set to be smaller than the inner diameter of the through hole 21, the rod-shaped member 22 with respect to the through hole 21 even when the rod-shaped member 22 is inserted through the through hole 21. It is in an unlocked state.
By pushing and pulling the other end side of the rod-shaped member 22 that is idle with respect to the through hole 21 from the outer peripheral surface side of the box joint 3, the split key member 5A is pushed and pulled over the accommodation position and the straddling position. Be manipulated. Therefore, in the present embodiment, the rod-shaped member 22 also functions as the operation mechanism 18.

A gripping member 23 can be attached to the outer peripheral surface side of the box joint 3 of the through hole 21.
As shown in FIGS. 2 and 4, the gripping member 23 includes a body portion 23A that can be freely inserted into the through hole 21, a flange portion 23B that cannot be inserted into the through hole 21, and a tool or work such as a hexagon wrench. A head 23C for rotating the gripping member 23 with a member's finger is provided.
At the center of the body portion 23A, a hole portion 23D capable of screwing the other end side of the rod-shaped member 22 is provided.
The gripping member 23 moves in the direction along the axial direction of the rod-shaped member 22 by gripping the other end side of the rod-shaped member 22 that is idle with respect to the through hole 21 from the outer peripheral surface side of the box joint 3. To prevent. As a result, the split key member 5A is held in the accommodation position.
For example, in a factory or the like, the rod-shaped member 22 is gripped by the gripping member 23 in advance, the split key member 5A is assembled at the accommodation position, and the rod-shaped member 22 is transported to the site in that state to connect the steel pipe piles A (1A, 1B). In the above, since the holding of the split key member 5A at the accommodation position can be released only after the steel pipe piles A (1A, 1B) are fitted to each other, the amount of work and the work time at the site can be reduced. ..
In the present embodiment, the rod-shaped member 22 and the gripping member 23 form a holding mechanism capable of holding the split key member 5A in the accommodation position.

As shown in FIGS. 8, 10 and 12, a male screw portion 24A that can be screwed into the female screw portion 21A formed on the inner peripheral surface of the through hole 21 is provided in the through hole 21. A tubular male screw member 24 can be arranged.
At the center of the male screw member 24 in the radial direction, there is an opening into which the rod-shaped member 22 can be loosely inserted, and as a fitting portion into which a tool such as a hexagon wrench for screwing the male screw member 24 can be fitted. , A screwing operation hole 25 is provided.

As described above, the split key member 5A is moved from the accommodating position to the straddling position by pushing the other end side of the rod-shaped member 22 that is idle into the through hole 21 from the outer peripheral surface side of the box joint 3. It is pushed in. Then, while the rod-shaped member 22 provided in the split key member 5A is loosely inserted into the inside of the screwing operation hole 25 of the male screw member 24, the male screw member 24 is inserted into the female screw portion of the through hole 21. The split key member 5A is straddled by shallowly screwing into 21A, fitting a tool such as a hexagon wrench into the screwing operation hole 25, and screwing the male screw member 24 to press the split key member 5A. Maintained in position.

The rod-shaped member 22 does not push the split key member 5A from the accommodation position to the straddling position, but the male screw member 24 is screwed to press the division key member 5A to press the division key member 5A at the accommodation position. 5A may be pushed into the straddle position. In this case, the male screw member 24 also functions as the operating mechanism 18.

The male screw member 24 is screwed into the through hole 21 so that the box joint 3 and the pin joint 4 are fitted to each other, and the male screw member 24 comes into contact with the split key member 5A to maintain the split key member 5A in a straddling position. Configure a maintenance mechanism to do this.

The length of the male screw member 24 is configured so that it does not protrude from the outer peripheral surface of the box joint 3 when the split key member 5A is pushed into the straddling position. Therefore, after the male screw member 24 is screwed in, the male screw member 24 does not protrude from the outer peripheral surface of the steel pipe pile A (1A, 1B).

As shown in FIG. 10, a peripheral groove 27 is further formed in the through hole 21 near the outer peripheral surface of the box joint 3. A snap ring 28 for a hole can be freely attached to the peripheral groove 27. The peripheral groove 27 and the snap ring 28 constitute a dropout prevention mechanism that prevents the male screw member 24 from falling out of the through hole 21 when the split key member 5A is maintained at the straddling position. As a result, even if the male screw member 24 rotates due to vibration during the burying work of the steel pipe pile A (1A, 1B), the split key member 5A maintains the straddling position, and the box joint 3 and the pin joint 4 There is no risk that the connection will be broken.
A notch 24B is formed in the circumferential direction on the side of the male screw member 24 that does not face the split key member 5A so that the snap ring 28 can be easily attached.

The procedure for connecting the steel pipe piles 1 (1A, 1B) adjacent to each other on the upper and lower sides will be described below.
First, the lower steel pipe pile A2 is embedded first with the pin joint 4 facing upward.
A rod-shaped member 22 is loosely inserted into each inward groove portion 11 of the box joint 3 of the steel pipe pile A1 connected to the upper side, and each division key member 5A is accommodated inside the inner peripheral surface portion 9. Assemble to. At this time, the gripping member 23 is attached to the outer peripheral surface side of the box joint 3 of the through hole 21, and the other end side of the rod-shaped member 22 is gripped from the outer peripheral surface side of the box joint 3, so that the rod-shaped member 22 is in the axial direction. Prevent movement in the direction along the. As a result, the split key member 5A is held in the accommodation position.
In this state, the box joint 3 is turned downward and lifted by a crane, and the pin joint 4 is held upward so as to be substantially concentric with the lower steel pipe pile A2 embedded earlier.

Then, the upper steel pipe pile A1 is lowered so that the box joint 3 has each cylinder side notch recess 8 facing each shaft side notch recess 13, and the ridge 16 of the pin joint 4 is a peripheral groove of the box joint 3. It fits into the pin joint 4 of the lower steel pipe pile A2 so that the ridge 7 of the box joint 3 fits into the peripheral groove 15 of the pin joint 4.
The rotation restraint key 6 is fitted over each of the cylinder-side notch recesses 8 and the shaft-side notch recesses 13 and fixed to the pin joint 4 with the fixing bolts 19. As a result, the steel pipe piles 1 (1A, 1B) are connected to each other in a non-rotating state.

Before, after, or in parallel with the detenting work, the gripping member 23 is removed, and the rod-shaped member 22 is operated to cover the split key member 5A with the inner peripheral surface of the key extending all around the groove bottom surface 17A of the outward groove portion 17. Push it into the straddle position that comes into contact with.

The male screw member 24 is screwed into the female screw portion 21A of the through hole 21 to maintain each division key member 5A in the straddling position. As a result, the steel pipe piles 1 (1A, 1B) are connected to each other in a retaining state.

Finally, the snap ring 28 is attached to the peripheral groove 27 of the through hole 21. This prevents the male screw member 24 from falling out of the through hole 21.

If it becomes necessary to release the retaining state of the split key member 5A, the snap ring 28 and the male screw member 24 are removed, and the rod-shaped member 22 is pulled to accommodate each split key member 5A. Can be pulled back to.

In the above-described embodiment, the configuration in which the rod-shaped member 22 is attached to the split key member 5A even when the split key member 5A is in the straddling position has been described, but the present invention is not limited to this.
After removing the gripping member 23 from the through hole 21, the rod-shaped member 22 pushes the split key member 5A at the accommodating position into the straddling position, and the male screw member 24 is screwed into the female screw portion 21A of the through hole 21. The split key member 5A is fixed at the straddling position. After that, the rod-shaped member 22 may be removed from the split key member 5A.

Alternatively, after removing the gripping member 23 from the through hole 21, the rod-shaped member 22 is also removed from the split key member 5A, and then a male screwable to the female screw portion 21A formed on the inner peripheral surface of the through hole 21. The male screw member 24 provided with the screw portion may push the split key member 5A at the accommodation position into the straddle position, and the split key member 5A may be maintained at the straddle position as it is.
In this case, an opening for loosely inserting the rod-shaped member 22 is not required at the center of the male screw member 24 in the radial direction. However, it is necessary to provide the male screw member 24 with a fitting portion into which a tool such as a hexagon wrench for screwing the male screw member 24 can be fitted. The fitting portion may also have a configuration in which the notch portion 24B formed in the male screw member 24 is also used.
Other configurations are the same as those in the above-described embodiment.

In the above-described embodiment, the rod-shaped member 22 and the gripping member 23 are made of separate members, but the present invention is not limited to this. The rod-shaped member 22 and the gripping member 23 may be integrally formed. For example, the rod-shaped member 22 and the gripping member 23 are composed of hexagon bolts having a head having a size that cannot be inserted into the through hole 21. In this case, the hexagon bolt constitutes a holding mechanism capable of holding the split key member 5A in the accommodation position.
Other configurations are the same as those in the above-described embodiment.

In the above-described embodiment, the configuration in which the rod-shaped member 22 composed of the threaded rod is attached to the split key member 5A has been described, but the present invention is not limited to this example.
Instead of the rod-shaped member 22, a string-shaped member such as a wire may be attached to the central portion of the split key member 5A in the longitudinal direction, and the string-shaped member may be passed through the through hole 21.
When the split key member 5A is used to prevent the split key member 5A from coming off, the split key member 5A is assembled at the accommodation position, and the outer peripheral surface portion 12 is fitted to the inner peripheral surface portion 9, and the through hole is formed from the outer peripheral surface side of the box joint 3. The male screw member 24 is screwed into 21 to maintain the split key member 5A in the straddling position.
At this time, the string-shaped member is guided to the outer peripheral surface portion of the box joint 3 through the screwing operation hole portion 25 provided in the radial center of the male screw member 24.
Even with this configuration, when the split key member 5A is maintained at the straddling position by the male screw member 24, the split key member 5A is not engaged with the through hole 21 in the radial direction of the through hole 21. It is in a stopped state.

To release the retaining state of the split key member 5A, with the male screw member 24 removed, pull the string-shaped member connected to the split key member 5A from the outer peripheral surface side of the box joint 3 to straddle the box joint 3. The split key member 5A at the installation position can be pulled back to the accommodation position.
Other configurations are the same as those in the above-described embodiment.

In the above-described embodiment, the grip member 23 has a body portion 23A that can be freely inserted into the through hole 21, a flange portion 23B that cannot be inserted into the through hole 21, and a head for rotating with a hexagon wrench or the like. Although the configuration has been described in which the 23C is provided and the hole portion 23D capable of screwing the other end side of the rod-shaped member 22 is provided in the center of the body portion 23A, the present invention is not limited to this example.
As shown in FIG. 13, the gripping member 23 may be, for example, a key push nut 29 capable of gripping the other end side of the rod-shaped member 22. The key push nut 29 is provided with a claw portion 29A having an angled inner circumference, and the tip of the claw portion 29A bites into the outer periphery of the rod-shaped member 22 so that the rod-shaped member 22 can be gripped so as not to move. ..
Other configurations are the same as those in the above-described embodiment.

In the above-described embodiment, the holding mechanism is composed of a rod-shaped member 22 and a gripping member 23, and the gripping member 23 is provided with a body portion 23A, a flange portion 23B, and a head portion 23C, and a rod-shaped member is provided in the center of the body portion 23A. The case where the hole 23D capable of screwing the other end side of the 22 is provided has been described. However, the configuration of the grip member 23 is not limited to this.

For example, as shown in FIG. 15, the gripping member 23 may be a so-called laundry scissors or crocodile clip-shaped clip (or clamp) 30. By gripping the other end side of the rod-shaped member 22 that is idle with respect to the through hole 21 from the outer peripheral surface side of the box joint 3, such a clip 30 moves in the direction along the axial direction of the rod-shaped member 22. Can be blocked from moving. As a result, the split key member 5A is held in the accommodation position. In this case, the male screw may not be formed on the rod-shaped member 22. In any case, the holding mechanism is a split key from the outer peripheral surface side of the box joint 3 via the through hole 21 when the outer peripheral surface portion of the pin joint 4 is not fitted to the inner peripheral surface portion of the box joint 3. Any configuration may be used as long as the member 5A can be held in the accommodation position.

The steel pipe connecting mechanism according to the present invention can be used for various purposes such as building support piles, landslide prevention piles, earth retaining column piles such as steel pipe sheet piles, partition walls, revetment walls, and structural columns. , In addition to the middle digging method, the driving method that is performed by hitting, the pre-boring method that inserts into the existing drilling hole, the soil cement synthetic pile method that is rotationally buried while creating soil cement, or simply rotating and press-fitting ( It can be sunk using the rotary burial pile method or the like. The rotation suppression key 6 is not always necessary when the method is such that the driving of the steel pipe does not involve rotation.
The steel pipe pile 1 (1A, 1B) may be buried in the ground with either the box joint 3 or the pin joint 4 facing upward.
Further, the steel pipe connecting mechanism according to the present invention can be applied to UO pipes, bending pipes, cast steel pipes cast by centrifugal casting, and the like.

The above-described embodiments are all examples of the present invention, and the description does not limit the present invention, and the specific configuration of each part can be appropriately modified and designed within the range in which the effects of the present invention are exhibited. is there.

2: Steel pipe 3: Box joint 4: Pin joint 4a: Key member 5A: Split key member 9: Inner peripheral surface portion 11: Inward groove portion 12: Outer peripheral surface portion 17: Outer groove portion 18: Operation mechanism 20: Outer peripheral surface 21: Penetration Hole 22: Rod-shaped member 23: Gripping member 30: Clip (grip member)
X: Axis

Claims (10)

A box joint is provided on one of the steel pipe ends facing each other in the direction of the steel pipe axis, and a pin joint that can be fitted in the box joint is provided on the other side of the steel pipe ends facing each other.
An inward groove portion along the circumferential direction is formed on the inner peripheral surface portion of the box joint, and an outward groove portion along the circumferential direction is formed on the outer peripheral surface portion of the pin joint, and the outer peripheral surface portion of the pin joint is the box joint. It is formed so as to face the inward groove portion while being fitted to the inner peripheral surface portion.
A plurality of split key members are provided around the steel pipe axis so as to be accommodated in the accommodating position in which the inward groove portion is inserted into the inner peripheral surface portion of the box joint.
In a state where the outer peripheral surface portion of the pin joint is fitted to the inner peripheral surface portion of the box joint, each of the split key members at the accommodation position is straddled over the inward groove portion and the outward groove portion. It is a steel pipe connecting mechanism that can be pushed into and connected to each other of the adjacent steel pipes facing each other in a retaining state.
The box joint is provided with through holes that communicate from the outer peripheral surface portion of the box joint to the inward groove portion corresponding to each of the split key members.
In the through hole, when the outer peripheral surface portion of the pin joint is fitted to the inner peripheral surface portion of the box joint, the split key member abuts on the surface of the split key member and the split key member is placed at the straddling position. A maintenance mechanism to maintain can be attached,
When the split key member is maintained at the straddling position by the maintenance mechanism, the split key member is unlocked with respect to the through hole in the radial direction of the through hole. .. When the maintenance mechanism maintains the split key member at the straddle position,
The steel pipe connecting mechanism according to claim 1, wherein a dropout prevention mechanism for preventing the maintenance mechanism from falling out of the through hole is provided so as to be freely mounted in the through hole. The through hole is provided with a female screw on the inner peripheral surface thereof.
The maintenance mechanism according to claim 1 or 2, wherein the maintenance mechanism includes the female screw provided on the inner peripheral surface of the through hole and a male screw member provided with a male screw that can be screwed into the female screw. Steel pipe connecting mechanism. When the outer peripheral surface portion of the pin joint is not fitted to the inner peripheral surface portion of the box joint, the split key member is held at the accommodation position from the outer peripheral surface portion side of the box joint through the through hole. The steel pipe connecting mechanism according to any one of claims 1 to 3, further comprising a possible holding mechanism. The holding mechanism is
One end side is connected to the split key member, and the other end side is a rod-shaped member or a string-shaped member that can be freely inserted into the through hole.
The steel pipe connecting mechanism according to claim 4, further comprising a gripping member capable of gripping the other end side of the rod-shaped member or the string-shaped member from the outer peripheral surface side of the box joint. The male The threaded member, a steel pipe connecting mechanism according to claim 5 which indirectly quoted claim 3 tools that are equipped with mateable fitting portion for causing the screwing of the male screw member. The fitting portion is composed of an opening formed at the center of the screw-advancing axis of the male screw member.
The steel pipe according to claim 6, wherein the rod-shaped member or the string-shaped member can be loosely inserted into the opening when the male screw member maintains the split key member in the straddling position. Connecting mechanism. Any of claims 4 to 7, which directly or indirectly cites claim 3, wherein the male screw member also functions as an operation mechanism capable of pushing the split key member at the accommodation position into the straddling position. The steel pipe connecting mechanism according to paragraph 1.
The rod-shaped member is
Any one of claims 5 to 8 that also functions as an operating mechanism capable of pushing and pulling the split key member from the outer peripheral surface side of the box joint through the through hole to the accommodation position and the straddling position. The steel pipe connecting mechanism described in the section. The string-shaped member is
The item according to any one of claims 5 to 8, which also functions as an operation mechanism capable of pulling back the split key member at the straddling position to the accommodation position through the through hole from the outer peripheral surface side of the box joint. Steel pipe connecting mechanism.

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