JP3167163B2 - Direction control mechanism of advanced equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot pipe laid in the first step of a propulsion method in the field of small-diameter propulsion method in which cable pipes, water and sewage pipes, gas pipes, etc. are laid in the soil without excavation. In the direction control mechanism of the tip device, which is a role of leading the above.

[0002]

2. Description of the Related Art FIGS. 3A to 3D are explanatory views showing an example of a procedure for laying a pipe by a small-diameter propulsion method. The main pushing device C is installed in the starting shaft A, the tip jack is extended and the tip head is pressed into the soil, and then the main pushing jack of the main pushing device C in the starting shaft A is extended to extend the leading device E and the pilot. The pipe D is press-fitted (FIGS. 1 and 2). Then, the pilot pipes D are sequentially screwed up one by one by a length corresponding to the propulsion length of the tip device E. The above steps correspond to the first step of the propulsion method.

[0003] In this way, the tip device E is moved to the arrival shaft B
Is reached, the tip device E is removed, and the pipe retraction device F is attached to the leading pilot tube D (FIG. 3C). Then, the pipe G to be laid is attached to the pipe retraction device F, and the pipe G is sequentially pulled in by the main pushing device C using the pilot pipe D as a guide (FIG. D). At this time, the pilot pipes D are sequentially removed one by one by unscrewing to recover the pipes G by a length corresponding to the drawing length of the pipes G.

FIGS. 4 and 5 are longitudinal sectional views of a direction control mechanism of a conventional tip device in the first step of the small-diameter propulsion method described above. FIG. 4 shows a straight-moving direction control state, in which the projection 5a formed on a part of the projection fitting 5 is engaged with the concave portion 6a provided at one place of the spherical seat 6, thereby holding the spherical seat 6 straight. are doing. Therefore, since the columnar head 7 formed integrally with the spherical seat 6 is straightened, a straight-moving direction control state is set.

FIG. 5 shows a state in which the inclination direction is controlled. The projection 5a of the projection fitting 5 is disengaged from the recess 6a of the spherical seat 6, and the projection 5a is pushed on the surface other than the recess 6a by the force of the hydraulic cylinder 1. The spherical seat 6 is inclined by being applied. Therefore,
Since the head 7 formed integrally with the spherical seat 6 is inclined, the inclination direction is controlled.

Next, the function of the hydraulic motor 2 will be described. The shaft of the hydraulic motor 2 has a double shaft 3, 9 structure,
One shaft 3 transmits the rotational force to the piston rod 4 of the hydraulic cylinder 1, but is connected in a structure that does not hinder the reciprocation of the piston rod 4, and the other shaft 9 detects the rotation angle of the hydraulic motor 2. It is connected to a potentiometer 8 as a sensor. Then, since the piston rod 4 of the hydraulic cylinder 1 is rotated by the rotation of the hydraulic motor 2, the protrusion 5 integrated with the tip of the piston rod 4 can be rotated.

Moreover, the one shaft 3 of the hydraulic motor 2 is connected in a structure that does not hinder the reciprocating movement of the piston rod 4 of the hydraulic cylinder 1, so that the piston rod 4 of the hydraulic cylinder 1 6 and can be separated. Therefore, the rotation of the hydraulic motor 2 allows the protrusion 5a of the protrusion 5 to be moved to an arbitrary position in the rotation direction, and can be controlled in the straight traveling direction and the inclination direction shown in FIGS. The hydraulic motor 2
By converting the voltage change value due to the rotation of the potentiometer 8 connected to the other shaft 9 into a rotation angle and displaying it remotely in a local area, it is possible to confirm in which direction the control is being performed on the ground.

[0008]

As described above, the direction control mechanism of the conventional tip device has a head formed in a cylindrical shape, and the tip of the head is made flat so that the resistance of the earth and sand is uniformly received. The emphasis was on improving the accuracy of straight-line control. For this reason, the control function in the straight traveling direction and the inclination direction was good in a certain hard ground (ground having a hardness up to about 15 N value). However, in a very soft place where the hardness of the ground is N value 0 or less, such as a reclaimed land or soft ground, the resistance received from the earth and sand during directional control is small, and the reaction force due to this is small, so the head can be used in the soil. There was a problem that simply moving in a floating state had no effect of cutting the earth and sand, and the direction could not be controlled.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a directional control mechanism of a tip device which exerts an appropriate directional control function even on a soft ground. A structure in which a hydraulic cylinder and a hydraulic motor are arranged in series inside the body, and the rotation of the hydraulic motor is transmitted to the tapered head via the piston rod of the hydraulic cylinder, and the tapered head is eccentric from the center position of the piston rod The pin is rotatably connected by a pin at the set position, and the thrust of the hydraulic cylinder is transmitted to the taper head by a push pin arranged eccentrically from the center position of the piston rod of the hydraulic cylinder, and further pushed to the taper head. The compression force of the spring is always applied through the Ri, and broken section tapered head projecting from the tube tip to the rotation about the pin is to taper head tip position is configured so as to protrude from the outside of the tube body in a tilted state.

[0010]

1 and 2 are longitudinal sectional views of a main part of a specific example of a directional control mechanism of a tip device according to the present invention. FIG. 1 shows a state of controlling a straight traveling direction, and FIG. 2 shows a state of controlling a tilt direction. ing. Also in the direction control mechanism of the present invention, a hydraulic cylinder and a hydraulic motor are arranged in series similarly to the above-described direction control mechanism of the conventional tip device, and reference numeral 4 denotes a piston rod of the hydraulic cylinder.

Reference numeral 10 denotes a distal end outer cylinder, which is connected to an intermediate outer cylinder 11 by screws, and a liner 12 is rotatably mounted inside these. A taper head 13 is rotatably connected to the head piston 19 and a pin 17 inside the liner 12, and the pin 17 is located at a position eccentric from the center position of the piston rod 4. A bending piston 20 is screwed to the tip of the piston rod 4 of the hydraulic cylinder, and a push pin 21 is screwed to the bending piston 20 at a position eccentric from the center position of the piston rod 4. I have. A spring case 22 is attached to the bent piston 20.
The piston 20 and the spring case 22
The spring 23 is housed in a compressed state in the space defined by. The push pin 21 is always pressed against the rear end face of the tapered head 13 through a hole formed in the head piston 19, and the compressive force of the spring 23 acts even when there is no acting force from the piston rod 4. I have.

[0012]

As described above, although not shown, the direction control mechanism of the present invention is also equipped with a hydraulic cylinder and a hydraulic motor in the same manner as the conventional direction control mechanism. 13 can be made to protrude or retract from the front end of the distal end cylinder 10. The taper head 13 can be rotated by rotating the piston rod by the hydraulic motor. Therefore, since the position is changed in the rotation direction of the taper head 13, the inclination direction can be changed in any direction.

FIG. 1 shows a straight-moving direction control state, in which the hydraulic cylinder is in a contraction limit state. Therefore, the tip of the tapered head 13 is in a state of being retracted from the front end of the tip outer cylinder 10, and the earth and sand is buried in the gap of the tip outer cylinder 10, and the front end of the tip outer cylinder 10 is formed flat by the earth and sand. Control in the straight traveling direction becomes possible.

FIG. 2 shows a state in which the inclination direction is controlled, in which the piston rod 4 of the hydraulic cylinder is extended by a predetermined stroke. The piston rod 4 pushes the bent piston 20, and the push pins 21 and the pins 17
Because it is located at a position eccentric from the center of
The taper head 13 bends about the pin 17 as a rotation center with the push pin 21 interposed therebetween, and the tilt direction is controlled.

However, when the ground is soft, the reaction force due to the earth and sand acting on the slope of the taper head 13 is small, and therefore, the component force for operating the taper head 13 in the inclination direction is also small. 13 does not tilt and projects straight. In such a state, the distal end position of the tapered head 13 does not protrude from the outside of the distal end outer cylinder 10, so there is no braking effect at the distal end of the tapered head 13,
The direction control effect is also reduced. to solve this problem,
By using the compressive force of the spring 23 and applying a force to move the taper head 13 always in the inclined direction via the push pin 21, the distal end position of the taper head 13 is moved outside the distal end by the dimension H shown in the drawing. It can protrude from the outside of the tube 10.

As another function, the bent portion is protected by the elastic material tube 15 and the filling material 16 so that earth and sand do not enter into the bent portion around the rotation center of the pin 17. Reference numerals 14 and 18 denote rings having a divided structure.
Are held by these rings 14 and 18.

[0017]

As described above, according to the directional control mechanism of the tip device of the present invention, in addition to the effect of shearing earth and sand by the tapered head, the braking effect by the bending operation of the tapered head, the soft ground Appropriate direction control is also possible for the tilt direction. Therefore, it is extremely effective in the field of the small-diameter propulsion method in which cable pipes, water and sewage systems, gas pipes and the like are laid without cutting, especially when used for directional control during propulsion on soft ground.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a specific example of a direction control mechanism of a tip device according to the present invention, showing a state of controlling a straight traveling direction.

FIG. 2 is a longitudinal sectional view of a main part of a specific example of a direction control mechanism of the tip device according to the present invention, showing a tilt direction control state.

FIGS. 3A to 3D are explanatory views of an example of a procedure for laying pipes by a small-diameter propulsion method.

FIG. 4 is a longitudinal sectional view of a direction control mechanism of a conventional tip device.
This shows a straight traveling direction control state.

FIG. 5 is a longitudinal sectional view of a direction control mechanism of a conventional tip device.
9 shows a tilt direction control state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic cylinder 2 Hydraulic motor 4 Piston rod 10 Tip outer cylinder 11 Intermediate outer cylinder 13 Taper head 15 Tube of elastic material 16 Filling material 17 Pin 19 Head piston 20 Articulated piston 21 Push pin 22 Spring case 23 Spring

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akira Sawaguchi 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-3-202591 (JP, A) JP-A Heisei 1-207597 (JP, A) Japanese Utility Model 62-7487 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/06 311

Claims (2)

(57) [Claims] 1. A structure in which a hydraulic cylinder and a hydraulic motor are arranged in series inside a tube, and the rotation of the hydraulic motor is transmitted to a tapered head via a piston rod of the hydraulic cylinder, and the tapered head is a piston rod. The pin is rotatably connected by a pin at a position eccentric from the center position of the hydraulic cylinder, and the thrust of the hydraulic cylinder is transmitted to the taper head by a push pin arranged at a position eccentric from the center position of the piston rod of the hydraulic cylinder. This structure is such that the compression force of the spring is always applied to the taper head with a push pin interposed between it. It is configured so that the tip of the tapered head protrudes from the outside of the tube when it is bent and inclined. A directional control mechanism for a leading device. 2. A directional control mechanism for a tip device according to claim 1, wherein the tapered head is protected by a tube of elastic material and a filling material to prevent intrusion of earth and sand into the bent portion of the tapered head.