JPH10306687A - Division part structure of tip device for pipe jacking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient flexural strength and to facilitate a division work even at a vertical shaft in a limited space, in the division structure of a tip device for pipe jacking to effect piping of a pipe for laying a cable in earth through a compaction and non-earth removal system. SOLUTION: A flange 2 is arranged at a joining end part between front and rear structures C2 and C3 and the flange 2 is fastened by a division ring 1 from an outer periphery. The division ring 1 is composed of a plurality of division pieces and provided with a groove 5 fitted in the flange 2. Coupling together of division pieces is effected such that the head part of a bolt 6 rotatably arranged at the division piece is engaged with a notch 9 and fastening is effected by the bolt 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a divided structure of a tip device for pipe propulsion in which a cable laying pipe, a water pipe, a water pipe, a gas pipe, and the like are laid in the soil without excavation in a compacted and non-discharged manner. It is.

[0002]

2. Description of the Related Art A procedure for laying pipes in a compacted and non-discharged manner by a small-diameter pipe propulsion method will be described with reference to FIGS. This is a method of digging first from the starting shaft A to the reaching shaft B with the tip device C, and laying the pipe E by pushing in while adding the pipe E. The tip device C can be divided into a front structure C2 and a rear structure C3 at the joint surface C4, and a head C1 for pre-digging is provided at the tip of the front structure C2, and the head C1 is built in with a built-in tip jack. Can extend and retract.

(1) A starting device D having a main pushing jack D1 and a tip device C for pipe propulsion are arranged in a starting shaft A (FIG. 7A). At this time, the rear structure C3 is arranged so that the rear end thereof can be pressed by the original pushing jack D1.

(2) The main push jack D1 is extended and the tip device C is pressed into the reaching shaft (FIG. 7B). (3) Pull back the jack D1, and secure an interval corresponding to the length of the pipe E between the rear end of the tip device C and the pressing surface of the main pushing jack D1 (FIG. 7C). (4) Insert the tube E into this space (FIG. 7D).

(5) The head C1 of the tip device is extended with a tip jack to dig first in the soil (FIG. 8A). (6) The main push jack D1 is extended, and the tip device C and the pipe E are pushed toward the arrival shaft by the length of the excavation (FIG. 8).
B). (7) As described above, the pipe E is laid while being added by repeating the steps of “first excavation → push-in of the pipe E and the tip device C → retraction of the main push jack D1 → placement of the next pipe → first excavation”. . The head C1 can slightly swing with respect to the front structure C2 (FIG. 8C), and performs excavation while correcting deviation in the propulsion direction (FIG. 8D).

(8) When the tip device C reaches the reaching shaft B (FIG. 9A), the front structure C2 and the rear structure C3 are separated at the joint surface C4, and the front structure C2 is moved to the reaching shaft B. (FIG. 9B). (9) Press the main push jack D1 until the rear structure C3 is completely exposed in the reaching shaft (FIG. 9C). (10) Then, the rear structure C3 is removed (FIG. 9D).

In the case of laying pipes by the above-mentioned consolidation and non-discharge method, since the pipes are not excavated and discharged during propulsion, the pressure resistance into the soil is very large. In particular, a large bending moment acts on the device itself when the direction is controlled by the tip device. Two structures shown in FIG. 10 and FIG. 11 are known as a divided portion structure of the tip device in consideration of such a bending moment.

The structure shown in FIG. 10 is a divided structure in which a front structure C2 and a rear structure C3 are joined using bolts G and nuts H. A plurality of bolts G are passed through the flanges at the joint ends of the front structure C2 and the rear structure C3, and the two structures C2 and C3 are joined by tightening with a nut H.

On the other hand, the structure shown in FIG. 11 is a divided structure in which the front structure C2 and the rear structure C3 are joined using the cap nut J. A male screw N is formed at a joint end of the front structure C2, and a flange O is formed at a joint end of the rear structure. One end is engaged with the flange O, and the other end is joined with a cap nut J having a female screw M screwed into the male screw N.

[0010]

However, the above-mentioned divided portion structure has the following problems. The split structure of FIG. 10 is not enough to withstand large bending moments. When a bending load acts on the lower part of the front structure in FIG. 10A, a tensile force acts on an upper part of the joint surface and a compressive force acts on a lower part thereof. At this time, the tensile force applied to the joint surface must be supported not by all bolts but only by bolts attached to the upper half of the pipe (FIG. 10B), which is not advantageous in terms of strength.

Although the structure of the division shown in FIG. 11 is advantageous in terms of strength against bending moment, it requires a large work space when dividing and removing the tip device. In this structure, when a bending load is applied below the front structure shown in FIG. 11, the tensile force applied to the upper part of the joint surface is supported by the upper half of the cross section of the cap nut, which is advantageous in terms of strength. However, as shown in FIG. 12, when the tip device is divided, it is necessary to rotate the cap nut to release the screw engagement with the front structure. At that time, since the front structure is moved in a direction away from the rear structure, an extra divided working space is required by a length corresponding to the screwing length. For this reason, when the inside of the reaching shaft is narrow, it may be difficult or impossible to divide the tip device.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a divided structure of a tip device having a sufficient bending strength and capable of easily performing a dividing operation even in a narrow shaft.

[0013]

SUMMARY OF THE INVENTION The present invention achieves the above object by providing a flange portion at a joint end of a front / rear structure, and attaching a split ring to the flange portion for joining. That is, the split ring has a groove fitted into the flange portion and is configured to be separable into a plurality of divided pieces, and each of the divided pieces has a connection mechanism with an adjacent divided piece. When dividing the tip device, the connection of the split pieces of the split ring may be released, and the split piece may be removed in the outer peripheral direction.

Here, the shape of the flange in both the front and rear structures is not particularly limited. However, it is preferable that the vertical cross-sectional shape of the flange portion in a state where both structures are joined is a trapezoid. When such a flange is tightened with a split ring from the outer periphery, the respective structures are pressed against each other in a joining direction, so that a higher bending strength can be obtained.

The groove of the split ring has a shape corresponding to the above-mentioned flange. Further, the number of divided pieces constituting the split ring is not particularly limited. As a connection mechanism of each divided piece,
A rotating shaft attached to one end of each divided piece, a rotatable bolt screwed to the rotating shaft, and a bolt head of an adjacent divided piece formed at the other end of each divided piece. One with a notch.

When a washer is used under the neck of the bolt,
It is preferable that the washer has a non-uniform thickness and a wedge-shaped cross section. Further, it is desirable that the engagement surface of the notch with which the washer under the bolt neck abuts is inclined at an acute angle with respect to the bottom surface of the notch. With these configurations, when the split ring is mounted on the flange and the bolt is tightened, the operation of turning the bolt with a decrease in the diameter of the split ring can be smooth.

[0017]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described based on Nos. FIG. 1A is a plan view showing a joined state of the divided portion structure of the present invention, FIG. 1B is a longitudinal sectional view thereof, and FIG. 2 is a transverse sectional view taken along line XX of FIG. 1B. 3 (A) is a plan view showing a separated state of the divided portion structure of the present invention, FIG. 3 (B) is a longitudinal sectional view thereof, and FIG. 4 is a view showing a state where a split ring is removed.
5 is a cross-sectional view taken along the line YY in FIG.

The split part structure of the present invention is a structure in which the front structure C2 and the rear structure C3 of the leading end device are abutted to each other, and the abutting portion is joined by tightening the outer periphery with the split ring 1.

The connecting end of the front structural body C2 and the rear structural body C3 has a substantially symmetrical structure, and has a flange 2 and a groove 3 (FIGS. 1A and 3). The flange 2 is an annular projection that projects outward from the joining surface C4, and the groove 3 is an annular recess that continues to the flange 1. In this embodiment, the outer diameter of the groove 3 is the smallest, the outer diameter of the flange 2 is the second largest, and the outer diameter of the front and rear structures other than the joint end is the largest. A circular groove is formed in the joint surface C4 of the front structure, and the O-ring 4 is inserted into this groove to prevent water from entering from the divided portion.

Here, the longitudinal sectional shape of the flange 2 when the two structures C2 and C3 were joined was a trapezoid (FIG. 1B). That is, the joined flange 2 has a wedge shape having an angle .theta.1, and the width is narrower on the outer peripheral side and wider on the inner peripheral side. As will be described later, the wedge shape can constitute a divided portion having a larger bending strength.

A split ring 1 is provided on the joint end of the two structures C2 and C3 (FIGS. 1B, 2 and 4). The split ring 1 is formed in an annular shape by connecting three arc-shaped divided pieces, and a groove 5 (FIG. 1B) into which the flange 2 is fitted is formed on the inner periphery, and both ends are adjacent to each other. It has a mechanism for connecting with the split pieces.

A rotatable hexagonal bolt 6 is used for this connection mechanism. Two grooves 7 are formed along the circumferential direction on the outer peripheral surface on one end side of each of the divided pieces, and the rotating shaft 8 is bridged in these grooves. A bolt 6 is screwed to the rotation shaft 8 in a direction perpendicular to the rotation shaft 8. On the other hand, the other end of each of the divided pieces has a notch 9 with which the head of the bolt 6 is engaged. The notch 9 has an L-shaped cross section formed while leaving the other end face of the divided piece, and is formed opposite to both sides of each divided piece to form an engagement surface 9A with a bolt head. The engagement surface 9A is provided with an inclination of an angle θ2 (FIG. 2). That is, the inner peripheral edge of the engagement surface 9A is close to the other end surface 1A of the divided piece, and the outer peripheral edge is inclined away from the other end surface 1A of the divided piece. And the engagement surface
A groove 10 is provided between 9A and the other end surface 1A of the divided piece, into which the shaft of the bolt 6 fits (FIG. 1B).

Further, in this embodiment, a square washer is provided under the neck of the bolt 6.
11 was attached. This square washer 15 is not uniform in thickness and has a wedge-shaped cross-sectional shape (FIGS. 2 and 4). The angle formed by the wedge-shaped cross section corresponded to the inclination angle θ2 of the engagement surface 9A. Due to the wedge-shaped square washer 11 and the inclination of the engagement surface 9A, when the split ring 1 is mounted on the flange 2 and the bolt 6 is tightened, the bolt head is rotated in the inner circumferential direction to secure the tightening. To

Although not shown, the front structure C2 is provided with a swingable head at the tip and a tip jack inside, and excavates the head by extending and retracting the head with the jack.

The procedure and operation for joining / dividing the above-mentioned divisions are as follows. (1) In the case of joining, both joining ends of the front structure C2 and the rear structure C3 are abutted, and the groove 5 of each divided piece is fitted to the flange 2 (FIGS. 1 and 2). (2) Each bolt 6 is rotated and engaged with the notch 9 of the adjacent divided piece. At this time, the square washer 11
The smaller one is aligned with the inner peripheral side of 9A and the outer peripheral side of engagement surface 9A.

(3) Each bolt 6 is screwed into the rotating shaft 8 and the adjacent divided pieces are tightened. The diameter of the split ring 1 becomes smaller as the bolt 6 is tightened, but the bolt 6 turns around the rotation shaft 8 to follow the change in the diameter.

(4) At the same time, when the square washer 11 slides along the engagement surface 9A, the head of the bolt 6 is smoothly fed to the inner peripheral side to facilitate the tightening. After tightening the bolt 6,
Engagement of the inclined engaging surface 9A and the wedge-shaped square washer 11 prevents the head of the bolt 6 from rotating to the outer peripheral side, so that the bolt 6 is hard to come off from the notch 9.

(5) When the trapezoidal flange 2 is tightened from the outer periphery with the split ring 1, the two structures C2 and C3 are pressed against each other, and sufficient joint strength is obtained even when a bending load is applied to the joint end. Can be secured.

(6) On the other hand, when separating, the bolts 6 are loosened from the state shown in FIGS. 1 and 2 (FIGS. 3 and 4). (7) After sufficiently loosening the bolt 6, the head of the bolt 6 is turned to the outer peripheral side to release the engagement with the notch 9, and the split ring 1 is divided into divided pieces.

(8) Then, the two structural bodies C2 and C3 are separated by removing each divided piece in the outer peripheral direction. When the split ring 1 is removed in this way, the two structures C2 and C3 can be separated from each other, and the front structure C2 can be pulled up directly. it can.

(Test Example) In order to confirm the strength of the above-mentioned divided portion structure, a prototype was manufactured and a strength test was performed. As shown in FIG. 5, the test method supported both ends of the tip device joined by the split part structure of the present invention, and applied a load to the central split part to check for deformation or breakage.

Distance between support points (L 1): 2 m Working point distance (L 1/2): 1 m Load (P 1): 48 TON When the test was performed under the above conditions, no deformation or breakage was observed in the prototype. , The normal form was retained. The bending moment (M1) at the point of action at this time is: M1 = (1/4) × P1 × L1 = (1/4) × 48 × 2
= 24 TON · m.

For comparison, the bending moment (M 2) acting on the divided portion of the tip device when the head of the tip device is extended by the tip jack to control the direction is obtained (FIG. 6).

Tip jack thrust (F2) built into the tip device: 100 TON Direction control angle (θ3): 1.5 ° Distance from the head to the junction of the tip device (L2): 2 m Bending direction component force (P) = 100 TON × sin1.5 ° × cos1.5 ° = 2.6TON Bending moment (M2) acting on the joint of the tip device = 2.6TON × 2m = 5.2TON · m

As described above, the divided structure of the present invention has a bending moment of about 4.
It was confirmed to have an extremely high strength of 6 times or more.

[0036]

As described above, according to the dividing structure of the present invention, the flange at the joint end is fastened by the split ring from the outer periphery, so that it has a high bending strength and can perform the dividing operation even when the reaching shaft is narrow. be able to.

Further, by making the shape of the flange a trapezoid, the front structure and the rear structure can be configured to be pressed against each other, so that a higher bending strength can be obtained.

Further, the cross section of the washer attached to the bolt is formed in a wedge shape, and the notch engaging surface with which the washer is engaged is also inclined, so that the rotation of the bolt is reduced due to the decrease in the diameter of the split ring which occurs when the bolt is tightened. It can be easily followed.

[Brief description of the drawings]

FIG. 1A is a plan view showing a joined state of a divided portion structure of the present invention, and FIG. 1B is a longitudinal sectional view thereof.

FIG. 2 is a partial cross-sectional view taken along arrow XX of FIG. 1B.

FIG. 3A is a plan view showing a separated state of the divided portion structure of the present invention, and FIG. 3B is a longitudinal sectional view thereof.

FIG. 4 is a cross-sectional view taken along the line YY of FIG. 3B showing a state in which a split ring is removed.

FIG. 5 is an explanatory view showing a test method of a strength test of the split part structure of the present invention.

FIG. 6 is an explanatory diagram for determining a bending moment acting on a dividing portion of the tip device.

FIG. 7 is an explanatory view of a pipe laying process of a consolidation non-discharge method using a tip device for pipe propulsion, wherein (A) is before excavation, (B) is when a main jack is extended, and (C) is a main jack. When retreating,
(D) shows the state when the pipe is attached to the main pushing device.

FIG. 8 is an explanatory view of a pipe laying process of a consolidation non-discharge method using a tip device for pipe propulsion, wherein (A) is for excavation, (B) is for extension of a main jack, and (C) is a tip device. When controlling the direction of
(D) shows when the tip device and the tube are pushed.

FIG. 9 is an explanatory view of a step of removing the tip device after reaching the reaching shaft, and (A) is a diagram when the tip device reaches the reaching shaft.
(B) shows the time of removal of the front structure, (C) shows the time of pushing the rear structure into the reaching shaft, and (D) shows the time of removal of the rear structure.

FIG. 10 shows a conventional divided portion structure using bolts,
(A) is a longitudinal sectional view, and (B) is a transverse sectional view.

FIG. 11 shows a conventional divided portion structure using a cap nut,
(A) is a longitudinal sectional view, and (B) is a transverse sectional view.

12 is a longitudinal sectional view showing a state in which the tip device of FIG. 11 is divided.

[Explanation of symbols]

1 split ring 2 flange 3 groove 4 O-ring
5 Groove 6 Bolt 7 Groove 8 Rotary shaft 9 Notch 9A Engagement surface 10 Groove
11 Square washer A Start shaft B Reach shaft C Tip device C1 Head C2 Front structure C3 Rear structure C4 Joint surface D Main push device D1 Main push jack E Pipe G Bolt H Nut IO Ring J Bag nut K O ring M Female thread N Male thread O Flange

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akio Kishi 1 Taya-cho, Sakae-ku, Yokohama-shi Inside Yokohama Works, Sumitomo Electric Industries, Ltd. (72) Inventor Minoru Tanaka 3-192-2 Nishishinjuku, Shinjuku-ku, Tokyo Japan Inside Telegraph and Telephone Co., Ltd. (72) Tetsuya Asano, Inventor 3-19-2, Nishishinjuku, Shinjuku-ku, Tokyo Japan Within Telegraph and Telephone Co., Ltd. (72) Junichi Shirakawa, 18-18, Moto-Asakusa 3-chome Moto Asakusa, Taito-ku, Tokyo (72) Inventor Toshio Akiyama 3-18-10 Motoasakusa, Taito-ku, Tokyo Inside IREC GIKEN

Claims (5)

[Claims] 1. A divided structure of a tube propulsion tip device for joining and separating a front structure and a rear structure, wherein each of the structures has a flange at a joint end thereof, and is fitted to the flange. The two structures are joined by a split ring having a mating groove, and the split ring is configured to be separable into a plurality of split pieces, and each split piece includes a coupling mechanism with an adjacent split piece. Split section structure of advanced equipment for pipe propulsion. 2. The vertical cross-sectional shape of the flange portion in a state where the front structure and the rear structure are joined to each other is trapezoidal, and the groove of the split ring has a shape corresponding to the flange. 2. A divided structure of the pipe propulsion tip device according to 1. 3. A coupling mechanism comprising: a rotating shaft attached to one end of each of the divided pieces; a rotatable bolt screwed to the rotating shaft; and a bolt head formed at the other end of an adjacent divided piece. 2. The split part structure of a tube propulsion tip device according to claim 1, further comprising a notch with which the part engages. 4. The splitting device according to claim 3, wherein a washer is fitted under the neck of the bolt, and the washer has a non-uniform thickness and a wedge-shaped cross section. Part structure. 5. The split part structure for a tube propulsion tip device according to claim 3, wherein a washer is fitted under the neck of the bolt, and a notch engaging surface with which the washer abuts has an inclination.