JP3562978B2 - Mechanism for correcting the direction of excavation of the leading conduit - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a propulsion device used for a propulsion method such as a sewer pipe or an underground conduit, and more particularly to a digging direction correcting mechanism for maintaining a digging direction of a small diameter propulsion destination pipe in a set direction.
[0002]
[Prior art]
The propulsion method often used for the construction of sewers is to place a jack device for propulsion in a shaft that has been constructed in advance, and to thrust the leading conduit from the starting port opening in the shaft in the direction of excavation by this jack device. The excavation is performed by moving the excavator while giving it, and a propulsion pipe is constructed by connecting the propulsion pipes one by one to the leading pipe.
[0003]
In such a propulsion method, it is necessary to strictly control the traveling direction of the conduit ahead of the propulsion device so that the position and direction from the starting wellhead are maintained as designed. That is, when the front pipe excavates the ground by the thrust by the jack device and the rotation of the cutter at the tip, the traveling direction of the front pipe may be bent depending on the conditions of the ground and the characteristics of the propulsion machine. For this reason, it is necessary to continuously monitor the pointing direction of the leading pipe during the period until the completion of the excavation, and when it deviates from the traveling direction, by controlling the attitude of the leading pipe to be changed, the original set drilling direction and The correction operation is performed.
[0004]
As a method of correcting the excavation direction of such a front pipe, a swinging method or an oblique pipe method has been mainly used.
[0005]
In the swinging method, the tip of the leading pipe is connected to the body of the leading pipe by a spherical joint, and a hydraulic jack for swinging the tip of the leading pipe is arranged. The tip of the leading conduit for swinging can be divided into a method of moving the cutter head itself and a method of moving a hood arranged on the outer periphery of the cutter head.
[0006]
In such a swing type, the one that swings the cutter head itself is excellent in that the direction of excavation can be corrected reliably, but the one that swings the hood is said to have a slightly lower correction effect. ing.
[0007]
On the other hand, the inclined pipe system includes two systems using a pilot tube and using a hood. The pilot pipe system is equipped with a pilot pipe that is arranged coaxially with the cutter head, the tip of which is cut obliquely and closed by an inclined plate.When the propulsion unit goes straight, it rotates with the cutter head to correct the propulsion direction. In some cases, the pilot pipe is stopped so that the pilot pipe is located in a direction opposite to the direction in which the inclined surface at the tip is bent. During the period in which the rotation of the pilot pipe is stopped, the pilot pipe is bent and propelled in a direction that minimizes the earth pressure resistance because the diameter of the pilot pipe is small. Therefore, by detecting the direction of the inclined plane of the pilot pipe, the direction in which the excavation turns can be known. In the hood type, the tip of the hood provided at the tip of the leading conduit is beveled, and the cutter head can move out and out of the hood. When moving straight, the cutter head protrudes from the hood and excavates to kill the influence of the hood, and when correcting the direction, the cutter head is retracted into the hood, and the digging direction is corrected using the unequal length direction of the hood are doing.
[0008]
[Problems to be solved by the invention]
However, in the case of the swinging type, a hydraulic jack and a spherical joint are required in any configuration for swinging the cutter head or the hood. Therefore, the capacity occupied by the hydraulic jack and the spherical joint increases, and it is difficult to cope with the case of a small-diameter propulsion pipe. On the other hand, if the hydraulic jack is reduced in size, a high-pressure hydraulic circuit is necessary to obtain the required swinging torque, and leakage of hydraulic oil, stress of members, and the like pose new problems.
[0009]
In addition, the production cost of spherical joints is high and maintenance management is also complicated.If the gap becomes large due to wear or the like, the stroke of the hydraulic jack is absorbed by this gap, and the amount of swinging of the cutter head and hood is insufficient. And the swing angle cannot be detected sufficiently.
[0010]
On the other hand, in the case of using the inclined pipe type pilot pipe, the outer diameter of the pilot pipe is small, so that the propulsion resistance can be suppressed low. However, since the pilot pipe and the front pipe are driven in two stages, the structure becomes complicated. Prone. Also, in the case of a hood having a bevel, the function of correcting the direction is not sufficient in comparison with the swing type.
[0011]
The problem to be solved in the present invention is to provide a mechanism for correcting the direction of excavation in a propulsion device that has a simple structure and can be applied to a small-diameter propulsion device.
[0012]
The present invention is directed to a forward conduit propelled in a digging direction by a thrust from a propulsion device, wherein a cutter head is rotatably mounted at a tip of the forward conduit, and excavated from the cutter head via the forward conduit. The cutter head is a tapered , substantially partial cone , the tip of which includes the center of the cross section of the front conduit and has a fan-shaped peripheral surface extending toward the base end side. It is characterized by comprising a taper block and a bit for excavation arranged on a peripheral surface of the taper block.
[0013]
In such a configuration, a drive motor for rotationally driving the cutter head is disposed inside the front conduit, and is arranged coaxially with the center of rotation of the cutter head and around a rotation axis connected to the drive motor. The apparatus may further include a disk for detecting a rotation angle, and further include a detection unit configured to detect a rotation angle of the rotation shaft using an outer periphery of the disk as an observation surface.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic longitudinal sectional view showing a main part of a distal end portion of a propulsion device according to the present invention, and FIG. 2 is a front view seen from the distal end side.
[0015]
In the figure, a cylindrical front conduit 1 incorporates a drive motor 2 with a speed reducer at the distal end thereof, and a drive shaft 2b coaxially connected to an output shaft 2a of the drive motor 2 via a spline joint 2c. The head block 1a to be supported is fixed integrally.
[0016]
The forward conduit 1 is propelled by a propulsion pipe which is press-fitted from the starting shaft to the reaching shaft side by a propulsion jack, similarly to the propulsion device used in the conventional propulsion method. That is, the thrust of the propulsion device is applied from the starting port to the front pipe 1 through the propulsion pipe into the ground, and the ground is excavated. Then, the propulsion pipe is added and this press-fitting is repeated to construct a sewer. When the leading pipe 1 reaches the reaching shaft, only the leading pipe 1 is collected on the ground side.
[0017]
In such a propulsion method, it is important to monitor the propulsion direction of the leading conduit 1. In order to monitor the propulsion direction, a television camera 3a for measuring the displacement of the leading conduit 1 by receiving a laser from a laser projector (not shown) for monitoring the propulsion direction provided in the shaft on the starting side is used. A remote inclinometer 3b for measuring the inclination of the conduit 1 is arranged.
[0018]
The head block 1a of the front conduit 1 includes a bearing 1b for supporting the drive shaft 2b, a seal ring 1c for sealing, and an annularly formed earth discharging chamber 1d. A plurality of openings 1e are opened on the front side of the earth discharging chamber 1d, and an earth discharging pipe 1f is connected to the rear side. The discharge pipe 1f is connected to a compressed air supply pipe at the distal end side and a vacuum pump installed on the ground side at the distal end side, and discharges excavated earth and sand by supplying compressed air and evacuation as in the conventional case. I do.
[0019]
Further, a ring bank 1g protruding forward is provided on the outer peripheral edge of the front end surface of the head block 1a, and a cylindrical guide sleeve 1h is provided at the center. A drive shaft 2b is rotatably inserted into the guide sleeve 1h, and a cutter head 4 is coaxially connected to a hexagonal shaft 2b-1 at the tip of the drive shaft 2b. The cutter head 4 has an eccentric sleeve 4a at the portion rotatably inserted around the guide sleeve 1h, and a crusher 5 is fitted and fixed integrally to the outer periphery of the eccentric sleeve 4a.
[0020]
The crusher 5 is, for example, a conical cone with a tapered distal end, and the eccentricity of the eccentric sleeve 4a causes rotation between the outer peripheral surface of the crusher 5 and the inner peripheral surface of the ring bank 1g as shown in FIG. Crushing blocks such as rocks by spreading and narrowing. Of course, the radius of the crusher 5 on the base end side (the right end side in FIG. 1) should not be so large that the opening 1e of the head block 1a is closed. It flows into 1d by the propulsive force of the leading conduit and the suction force of the discharging pipe.
[0021]
As shown in FIG. 2, the cutter head 4 is provided with a tapered block 4b which is inferior in arc shape and has a central angle of 180 ° or less and is tapered, and two rows of cone-shaped bits 6a and 6b. The bits 6a and 6b are mounted so that the tip points in different rotation directions, and can be excavated in both the forward rotation direction and the reverse rotation direction of the cutter head 4; An overcut of about 5 to 10 mm from the outer periphery of the conduit 1 is made.
[0022]
Here, the cutter head 4 occupies only a subarc-shaped area with respect to the entire cross section of the front pipe 1, and the tapered block 4b is similar to the diagonal pilot pipe or hood described in the conventional example. Bias against pressure. Then, since the excavation direction of the leading pipe 1 is corrected by using this uneven contact, it is necessary to know the turning posture of the cutter head 4. For this purpose, as shown in FIG. 1, a proximity sensor 7 is provided inside the front conduit 1, and three disks 8a, 8b, 8c are attached to the output shaft 2a of the drive motor 2.
[0023]
FIG. 4 is a schematic diagram showing a positional arrangement relationship between the proximity sensor 7 and the three disks 8a to 8c. A protruding portion on the outer periphery of the disks 8a to 8c is defined as a peak 8d, and a recessed portion is defined as a valley 8e. In the case of the disk 8a, the central angle 180 ° is the peak 8d and the remaining 180 ° is the valley 8e. In the disk 8b, the peaks 8d and the valleys 8e having the central angle of 90 ° are alternately arranged. And valleys 8e are arranged alternately. If the proximity sensor 7 indicates ON when approaching the peak 8d, and indicates OFF when the proximity sensor 7 is in contact with the valley 8e, the rotation angle of the output shaft 2a is digitally displayed at 45 ° intervals. Can be.
[0024]
In the above configuration, the leading pipe 1 connected to the tip of the propulsion pipe (not shown) driven by the propulsion jack of the starting shaft excavates by excavating the cutter head 4 attached to the tip. At this time, the cutter head 4 at the tip of the front pipe 1 occupies a part of the rotation cross section of the front pipe 1 and is deviated in the radial direction. However, since the cutter head 4 excavates the ground uniformly by rotary excavation, Its excavation direction is not bent. Then, as shown in FIG. 5A, excavation is performed while forming an overcut around the front pipe 1 by the bits 6a and 6b as shown by hatching areas in the figure, and the ground at the cutter head 4 is almost completely removed. Drilled into a truncated cone.
[0025]
The rotation direction of the cutter head 4 can be switched by the control of the drive motor 2. In FIG. 2, when the cutter head 4 rotates in the clockwise direction, the excavation is performed by the bit 6a. Done. When the cutter head 4 rotates, the crusher 5 attached around the eccentric sleeve 4a also rotates. That is, in FIG. 3, the crusher 5 is biased downward with respect to the ring bank 1g, but the direction of the eccentricity gradually changes due to the rotation of the cutter head 4, and the gap between the link bank 1g and the peripheral surface of the crusher 5 is increased. It expands and contracts periodically. Therefore, the excavated rock mass or the like is compressed and crushed by the crusher 5 with the ring bank 1g, and the excavated earth and sand and the crushed portion are sent to the earth removal chamber 1d from the opening 1e and discharged from the earth discharge pipe 1f. You.
[0026]
Here, since the cutter head 4 may collide with a boulder or the like included in the ground while the excavation of the front pipe 1 is in progress, the propulsion direction may be bent, and thus such bending is corrected. For example, when the propulsion direction is detected to be tilted above a predetermined trajectory by imaging with the television camera 3a, the cutter head 4 is first moved as shown in FIGS. The conduit 1 is stopped at a position above the rotational section. The setting of the position of the cutter head 4 can be executed by using the proximity sensor 7 and the three disks 8a, 8b, 8c shown in FIG.
[0027]
Next, the propulsion jack of the starting shaft is driven to add thrust to the leading conduit 1. At this time, the ground portion into which the cutter head 4 enters enters is softened by the rotation of the cutter head 4 before the thrust is applied, and the soil is discharged, so that the density is low. That is, in FIG. 5A, the ground in the area indicated by hatching below the tapered block 4b of the cutter head 4 is soft and sparse, so that when thrust is applied to the front conduit 1, the cutter head 4 Reference numeral 4 changes the posture by applying a force in the direction of the arrow shown in FIG. Therefore, the conduit 1 gradually changes its axis obliquely downward, and its position also moves downward.
[0028]
After confirming with the television camera 3a that the position of the leading pipe 1 has been lowered in this way, the driving motor 2 is restarted to rotate the cutter head 4, and the excavation is resumed. At this time, the repaired state of the displacement is confirmed by imaging with the television camera 3a, and if the correction is not correct, the previous correction is repeated, and the leading pipe 1 is excavated based on the corrected posture. The excavation direction of 1 is corrected to the planned position.
[0029]
In addition, since the displacement of the leading pipe 1 in the propulsion direction has a more significant influence on the excavation than the displacement in the vertical direction than in the left and right directions, the displacement of the leading pipe 1 is calculated by the remote inclinometer 3b provided inside the leading pipe 1. Check the angle of inclination outside to ensure corrective action. That is, for vertical and horizontal displacements, the cutter head 4 is rotated to the same side as the displaced direction and stopped, and thereafter the excavation direction of the leading pipe 1 may be corrected in the manner described above. .
[0030]
FIGS. 6 to 8 show another example, in which a bit provided in the cutter head 4 is a commonly used excavation bit, and the rotation angle of the cutter head 4 can be detected in an analog manner. It is. The same components as those in the previous example are designated by the same reference numerals, and detailed description thereof will be omitted.
[0031]
As shown in FIGS. 6 and 7, three rows of bits 9 a, 9 b, and 9 c are attached to the tapered block 4 b of the cutter head 4. These bits 9a to 9c are commonly used in a conventional cutter for a leading pipe. A non-contact displacement sensor 10 is provided inside the front conduit 1, and a disk 11 for detecting the rotation posture of the cutter head 4 is attached to the output shaft 2 a of the drive motor 2.
[0032]
The non-contact displacement sensor 10 is of an optical or electric type and outputs a signal according to the distance between the sensor and the peripheral surface of the disk 11. As shown in FIG. 7, the disk 11 has an outer peripheral surface in which the radius of the entire circumference around the center changes uniformly, and the relationship between the rotation angle and the distance to the non-contact displacement sensor 10 is calculated in advance. By incorporating it in the system, the rotation angle of the disk 11 can be known. Therefore, the rotation angle of the cutter head 4 can be detected using the rotation posture of the disk 11 as in the previous example.
[0033]
Also in the configurations of FIGS. 6 to 8, when the excavation direction of the leading conduit 1 is shifted, the excavation direction can be corrected by setting the position of the cutter head 4 on the same side as the displacement direction.
[0034]
Note that the bits 9a to 9c have a shorter protruding length than the cone-shaped bits 6a and 6b in the above example, but the state of excavation around the cutter head 4 is slightly different. However, in the correction of the excavation direction of the leading conduit 1, no matter which bit is used, the direction is corrected using the fact that the earth and sand around the tapered block 4b is excavated and softened and becomes sparse due to earth removal. The difference does not determine the quality of the correction in the excavation direction, and a good correction operation can be performed in any case.
[0035]
【The invention's effect】
According to the first aspect of the present invention, since the excavation direction can be corrected only by forming a taper block on the cutter head, machining is difficult and an expensive swinging mechanism such as a spherical joint or a hydraulic jack or a sliding mechanism is not required. It can be made compact with a simple structure and can be optimally used for small-diameter propulsion machines.
[0036]
According to the second aspect of the present invention, the rotation angle of the rotating shaft in the front conduit can be known by the surrounding disk and the detection means arranged in the front conduit, so that the target can be detected by an optical means such as a telescope from the starting shaft, for example. Compared to the case of observing the rotation angle by observing, the rotation angle can be accurately grasped regardless of the distance of the target, and the posture of the cutter head can be optimized to correct the digging direction. In addition, since it is not necessary to provide a space through which light passes from the starting shaft to the leading conduit, it is easy to arrange pipes, electric wiring, strength members, and the like in the propulsion pipe.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a main part of a front conduit and a cutter head provided with a propulsion direction correcting mechanism of the present invention.
FIG. 2 is a front view of the leading conduit and the cutter head as viewed from the distal end side thereof.
FIG. 3 is a longitudinal sectional view of a main part showing an eccentric structure of a crusher around an eccentric sleeve.
FIG. 4 is a schematic diagram showing an arrangement of a proximity sensor and a disk.
FIGS. 5A and 5B are schematic diagrams of a digging state, wherein FIG. 5A shows straight digging and FIG. 5B shows correction of a propulsion direction after being displaced downward.
FIG. 6 is a longitudinal sectional view of a main part showing an example in which a conventional drill bit and a non-contact displacement sensor are provided.
FIG. 7 is a front view of the example of FIG. 6;
FIG. 8 is a schematic view showing an arrangement of a non-contact sensor and a disk.
[Explanation of symbols]
Reference Signs List 1 front conduit 1a head block 1d discharging chamber 1e opening 1f discharging pipe 1g ring bank 1h guide sleeve 2 drive motor 2a output shaft 2b drive shaft 2c spline joint 3a TV camera 3b remote inclinometer 4 cutter head 4a eccentric sleeve 4b taper block 5 Crusher 6a, 6b Bit 7 Proximity sensor 8a, 8b, 8c Disk 8d Peak 8e Valley 9a, 9b, 9c Bit 10 Non-contact displacement sensor 11 Disk

Claims (2)

In lead pipe is propelled excavation direction by thrust from the propulsion unit, a cutter head which can be rotationally driven attached to the distal end of the destination conduit, the earth and sand excavated by way of the destination conduit from said cutter head ground A cutter tube, which is a tapered block having a tapered substantially partial conical shape , a distal end portion including a cross-sectional center of the front conduit, and a peripheral surface developed in a fan shape toward a base end side, A mechanism for correcting the direction of advance of the leading conduit, comprising a drill bit disposed on the peripheral surface of the tapered block. A drive motor for rotationally driving the cutter head is disposed inside the front conduit, and a disk for detecting a rotation angle around a rotation axis coaxially arranged with the rotation center of the cutter head and connected to the drive motor. 2. The excavation direction correcting mechanism for a leading conduit according to claim 1, further comprising: a detection unit configured to detect a rotation angle of the rotation shaft using an outer periphery of the disk as an observation surface.

Images