JP4440811B2 - Tunnel excavator and tunnel excavation method - Google Patents

Description

  The present invention relates to a tunnel excavator provided with an underground obstacle detection device and a tunnel excavation method.

  In recent years, with the construction of drain pipes and the like in urban civil engineering and sewerage works, there are increasing cases of encountering underground obstacles (obstacles such as ground anchors and H-shaped steel). In order to fix the structure to the ground, the ground anchor fixes both ends of the tensile material (a bundle of a plurality of strands of PC steel) to the structure and the ground, and the middle part stretches and deforms. Is a general term for a structure composed of an anchor body, a tension member, and an anchor head.

In this case, with a general shield excavator, it is difficult to remove the obstacle for the following reasons, and therefore, a human has gone out to the face outside the machine and removed it directly by gas cutting or the like.
(1) If an obstacle during cutting moves, the cutter head may become entangled, the shield excavator may not be able to dig, and the cutter bit may be lost.
(2) The fishtail cutter at the center of the cutter head is severely damaged.
(3) When an obstacle is cut with a normal cutter bit for earth and sand cutting, it is chipped.
(4) When the obstruction pieces that have been cut are large, the cutter head or the screw conveyor may be entangled and the shield excavator may be unable to dig.

  Conventionally, the above-described obstacles are indirectly detected by a so-called underground radar using a reflected wave of a sound wave or an electromagnetic wave.

JP-A-10-169376

  However, in the conventional detection device described above, since the device is complicated, the cost is increased and the presence of an obstacle cannot be determined unless the data obtained indirectly is analyzed. There was a problem that it was bad and lacked responsiveness.

  By the way, in Patent Document 1, in a shield excavator, a copy cutter for an extra moat is driven by a hydraulic jack, and the push side of the hydraulic jack when the copy cutter in the extra moor is subjected to a sudden reaction force of a natural ground. When the oil pressure exceeds the set value, the pressure oil on the push side of the hydraulic jack is instantaneously discharged and the copy cutter is immersed in the cutter head, so that damage to the copy cutter can be avoided in advance. A so-called safety device is disclosed.

  The present invention is a tunnel excavator and tunnel equipped with an underground obstacle detection device with low cost and high detection accuracy, by further developing such a safety device as an underground obstacle detection device. An object is to provide a drilling method.

In order to achieve the above object, a tunnel excavator according to the present invention includes a tubular excavator body, a propulsion jack for advancing the excavator body, and excavating a face supported by the excavator body so as to be driven to rotate. An excavator equipped with an obstacle detection unit that detects the presence of an obstacle by directly contacting the detection member with the obstacle on the cutter head. A monitoring device is provided for monitoring the detection status, and the detection member is formed in a semicircular shape in the same shape as the cutter bit mounted on the cutter head, and the tip of a hydraulic jack that extends and contracts within the obstacle detection unit body This is a detection bit that has a cutting function and can be switched between an immersion state and a protruding state as necessary. Bits hydraulic jack when contacted with obstacle detecting the presence of obstacles by contracting with an external force, characterized in that.

  Further, as the detection status, the position, stroke and hydraulic pressure of the hydraulic jack are monitored.

  Further, the obstacle detection unit is provided at a plurality of locations in the radial direction of the cutter head.

  Further, the obstacle detection unit is provided at a plurality of locations in the circumferential direction of the cutter head.

  The obstacle detection unit further comprises a control mechanism for stopping the expansion and contraction of the propulsion jack and the rotation of the cutter head when the obstacle detection unit detects the presence of the obstacle.

The tunnel excavation method of the present invention for achieving the above-described object is the obstacle having the above-mentioned characteristics mounted on the cutter head when the cutter head is rotated and the excavator body is advanced by a propulsion jack to cut the face. The presence of the obstacle can be detected by directly contacting the obstacle with the detection member of the obstacle detection unit, and the detection status by the obstacle detection unit is monitored.

  According to the tunnel excavator and the tunnel excavation method of the present invention, since the presence of an obstacle is detected by directly contacting the obstacle with the obstacle without using an indirect means such as electromagnetic waves, the cost can be reduced by simplifying the structure. In addition to being able to down, the detection accuracy is also improved, and the presence or absence of an obstacle can be grasped reliably.

  In addition, the detection member is attached to the tip of a hydraulic jack that is formed in a semicircular shape and expands and contracts within the obstacle detection unit body, and the hydraulic jack contracts by an external force when the detection member contacts the obstacle. By detecting the presence of an obstacle, the hydraulic jack can contract quickly and smoothly when an external force (reaction force) is applied, and the detection accuracy can be increased. Moreover, since the detection member is a detection bit having a cutting function, durability of the detection member can be improved. Further, by monitoring the position, stroke, and hydraulic pressure of the hydraulic jack as the detection status, it is possible to more reliably determine the presence or absence of an obstacle. Moreover, the obstacle detection accuracy can be increased by providing a plurality of obstacle detection devices in the radial direction or circumferential direction of the cutter head. In addition, when the obstacle detection unit detects the presence of an obstacle, it has a control mechanism that stops the expansion and contraction of the propulsion jack and the rotation of the cutter head, so that the soundness of the tunnel excavator can be maintained well. .

  Hereinafter, a tunnel excavator and a tunnel excavation method according to the present invention will be described in detail with reference to the accompanying drawings.

  1 is a side sectional view of a mud pressure shield excavator showing an embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is an enlarged sectional view of an obstacle detection unit, and FIG. 4 is an operation state of the obstacle detection unit. 5 is an overall configuration diagram of the obstacle detection device, and FIG. 6 is an explanatory diagram of the monitor.

  As shown in FIGS. 1 and 2, a cutter head 4 is freely rotatable via a bearing or the like on a bulkhead 3 of the excavator body 1 that forms a cylindrical shape of a mud pressure shield excavator (tunnel excavator). It is attached to. Six cutter spokes 5 are fixed to the front surface of the cutter head 4 by radiating from the center of rotation of the cutter head 4 with a face plate 6 disposed therebetween. A large number of cutter bits 7 are mounted on the cutter pork 5 and the face plate 6, and an obstacle detection described later is provided at the tip of the three equally spaced cutter porks 5 (the outer peripheral end of the cutter head 4). The unit 30 is mounted. A fishtail cutter 8 is attached to the center of rotation of the cutter head 4. Further, an appropriate number (two in the figure) of copy cutters 10 are mounted so that they can be extended and retracted (in and out) by a hydraulic jack 9 in the radial direction of the cutter head 4. A ring gear 11 is fixed to the rear portion of the cutter head 4.

  On the other hand, a cutter turning motor 12 as a cutter head driving means is attached to the partition wall 3, and a drive gear 13 of the cutter turning motor 12 is engaged with the ring gear 11. Therefore, when the cutter turning motor 12 is operated to drive the drive gear 13 to rotate, the cutter head 4 is rotated via the ring gear 11. A rotary joint 14 is assembled at the center of the partition wall 3, and pressure oil is supplied and discharged from a hydraulic source (not shown) to the hydraulic jack 9 and the like of the copy cutter 10 through the rotary joint 14. It is like that.

  A screw conveyor 17 is disposed inside the excavator body 1 so that earth and sand excavated by the cutter head 4 can be discharged to the rear of the tunnel. That is, the front end portion (outlet) of the screw conveyor 17 passes through the lower part of the partition wall 3 and opens into the chamber chamber 18 defined by the cutter head 4 and the partition wall 3, and the discharge port ( (Opened and closed by the gate 20 driven by the jack 19) is opposed to a belt conveyor (not shown) arranged in the longitudinal direction in the tunnel. The screw conveyor 17 is configured such that screw blades 17c are mounted in a cylindrical tube 17a disposed so as to incline rearward so as to be rotatable by a drive motor 17b.

  On the inner peripheral portion of the excavator body 1, a propulsion jack 22 that can be expanded and contracted with respect to an existing segment S constructed (assembled) on the inner peripheral surface of the tunnel as a lining member is spaced apart by a predetermined distance in the circumferential direction. Many of them are arranged. Further, the rear end portion of the excavator body 1 is fitted to the outer periphery of the existing segment S via a tail seal 23. In addition, an erector 25 for assembling the segment S and a rear overhang base 24 are assembled to the rear part of the excavator body 1, and a segment adjuster 26 for holding a perfect circle of the segment S assembled on the rear overhang base 24 is equipped. .

  As shown in FIGS. 3 and 4, the obstacle detection unit 30 is provided in a casing 5 a on the back of the cutter spoke 5, and has a cylindrical unit main body 31 and a hydraulic jack 32 housed in the unit main body 31. And a detection bit (detection member) 33 fixed to the tip of the cylinder 32a of the hydraulic jack 32.

  The detection bit 33 is of the same type as the cutter bit 7 mounted on the cutter head 4. That is, the tip end angle is an obtuse angle, and it is formed in a semicircular shape symmetrical to the cutting direction (the circumferential direction of the cutter head 4), so that one bit can cope with both the left and right rotations of the cutter head 4. It is. Therefore, cutting efficiency and durability are higher than general earth and sand cutting bits. Further, in order to lengthen the arc length of the detection bit 33, the bit width W is set larger than that of the cutter bit 7 mounted on the cutter head 4 (for example, 200 mm → 270 mm).

  The hydraulic jack 32 is configured such that its cylinder 32 a can slide in the digging direction through the metal bearing 34 in the unit main body 31 and cannot be rotated by a detent 35. On the other hand, the rod tip of the piston 32b accommodated in the cylinder 32a protrudes outside the cylinder 32a and is coupled to the unit body 31.

  When hydraulic pressure is supplied from the contraction line 36 of the hydraulic system, the hydraulic jack 32 contracts to the contracted limit state shown in FIG. 3 (the cylinder 32a slides backward in the digging direction), and conversely, the hydraulic pressure from the extension line 37 increases. Is supplied, the hydraulic jack 32 is extended to the extended limit state shown in FIG. 4 (the cylinder 32a slides forward in the digging direction). In the contracted limit state, the detection bit 33 is, for example, 50 mm lower (immersion state) than the cutter bit 7 mounted on the cutter head 4 to prevent wear and reduce the load during normal excavation. In this case, the detection bit 33 is, for example, 100 mm higher (projecting state) than the cutter bit 7 mounted on the cutter head 4, and when an obstacle is present on the face, the detection bit 33 is first encountered.

  As shown in FIG. 5, the hydraulic system of the hydraulic jack 32 in each obstacle detection unit 30 is an independent system for the purpose of individual operation, and hydraulic pressure is supplied to the cutter head 4 via the rotary joint 14 described above. is doing.

  Each hydraulic system is connected to a pump 39 and a tank 40 via an electromagnetic valve 38, and a relief valve 41, a pressure gauge 42, a pressure oscillator 43 and a flow meter 44 are interposed in the extension line 37, respectively. The detection signals of the pressure oscillator 43 and the flow meter 44 are operated together with the detection signals of the rotary encoder (cutter head turning angle sensor) 45 installed in the ring gear 11 (which can also be installed in the rotary joint 14). The position is input to the operation panel 46, and the position (angle), stroke, and hydraulic pressure (detection status) of each obstacle detection unit 30 are displayed on a monitor (monitoring device) 47 (see FIG. 6). The position is derived from the rotary encoder 45, the stroke is derived from the flow meter 44, and the hydraulic pressure is derived from the pressure oscillator 43. Accordingly, the obstacle detection device is constituted by each obstacle detection unit 30, its hydraulic system, and the operation panel 46 including the monitor 47.

  As shown in FIG. 6, the monitor 47 includes a lamp display unit 47 a that displays (lights) the positions of the three obstacle detection units 30 of No. 1 to No. 3 in different colors as blinking lamps, and No. 1. Numerical display 47b for displaying the hydraulic pressure, stroke and position of the three obstacle detection units 30 of No. 3 by color-coded numerical values, and hydraulic pressure and stroke of the three obstacle detection units 30 of No. 1 to No. 3 And a graph display section 47c for displaying the position in two different colors (present and previous) of the cutter head 4 in a color-coded manner, and three obstacles No. 1 to No. 3 under automatic control. An alarm display unit 47d that warns of malfunction of the detection unit 30 is provided.

  Because of this configuration, when excavating with the mud pressure shield excavator, first, the cutter head motor 4 is operated by operating the cutter turning motor 12 at the initial position where all the propulsion jacks 22 are contracted (the state shown in FIG. 1). Rotate.

  Next, all or arbitrary propulsion jacks 22 are extended from the above state, and the excavator body 1 is propelled (moved forward) by one stroke. At this time, the propulsion reaction force is received by the existing segment S. As a result of this propulsion, a number of cutter bits 7 attached to the cutter head 4 excavate the ground in front. The excavated earth and sand are discharged from the chamber chamber 18 to the outside by the screw conveyor 17 or the like.

  Next, with the cutter head 4 stopped turning, the propulsion jack 22 is partially contracted sequentially to assemble the segment S by the erector 25 and the segment adjuster 26, and hold the true circle.

  Thereafter, the above-described steps are repeated to excavate and form a tunnel having a predetermined length.

  When an obstacle such as a ground anchor or H-shaped steel is likely to be encountered under excavation, the turning of the cutter head 4 and the extension of the propulsion jack 22 are temporarily stopped and the hydraulic jacks of the respective obstacle detection units 30 are stopped. 32 is extended to the extension limit (for example, 150 mm), and then excavation is resumed. At this time, the relief valve 41 in the hydraulic system of each obstacle detection unit 30 is set to a minimum pressure value that can maintain an elongation limit stroke (for example, 150 mm) during earth and sand excavation.

  When the detection bit 33 of each obstacle detection unit 30 encounters an obstacle, the hydraulic jack 32 is shrunk by an external force (reaction force), and the hydraulic oil is released from the relief valve 41 at that time. This flow of hydraulic oil is converted into a stroke by the flow meter 44 and displayed on the monitor 47 of the operation panel 46 described above. The change in hydraulic pressure at this time is also displayed on the monitor 47 via the pressure oscillator 43 described above. Since the position of each obstacle detection unit 30 is always displayed on the monitor 47 as described above, the position of the obstacle can be accurately grasped.

  At this time, since the detection bit 33 is formed in a semicircular shape in the cutting direction, the cylinder 32 a of the hydraulic jack 32 is supported by the unit body 31 over a length of more than half by the metal bearing 34. In combination, when an external force (reaction force) is applied, the hydraulic jack 32 can be quickly and smoothly contracted, and the detection accuracy can be increased.

In order to improve the accuracy of obstacle detection and to maintain the soundness of the mud pressure shield excavator well, it is preferable to equip the following interlock mechanism (control mechanism).
(1) When any of the obstacle detection units 30 contracts to a preset stroke, an alarm such as a buzzer sounds is issued.
(2) The turning (rotation) of the cutter head 4 and the extension of the propulsion jack 22 are stopped when any of the obstacle detection units 30 contracts to a preset stroke.
(3) After any obstacle detection unit 30 contracts to a preset stroke, it automatically recovers to an expansion limit stroke (for example, 150 mm).

  In this way, in this embodiment, since the presence of an obstacle is detected by directly contacting the obstacle with the detection bit 33 without using an indirect means such as an electromagnetic wave, the cost can be reduced by simplifying the structure. At the same time, the detection accuracy is improved. In this embodiment, since the detection is performed three times for one rotation of the cutter head, the detection accuracy is further improved.

  In the above embodiment, an example in which three obstacle detection units 30 are mounted has been shown. However, as shown by a chain line in FIG. 2, three places using a stirring bar, a cutter head support beam 4a, etc. (not shown) are used. × 3 rows may be provided by changing the circumferential position (angle) as appropriate. Further, it may be 1 place × 9 rows or the like without providing the same locus. In short, the obstacle detection accuracy can be increased by increasing the number of obstacle detection units 30 mounted.

  Moreover, although the detection bit 33 which can be cut is used as the detection member in order to enhance durability, a simple semicircular block body having durability may be used. Further, the tunnel excavator is not limited to the mud pressure shield excavator but may be a mud shield excavator or a tunnel boring machine.

It is a sectional side view of a mud pressure type shield excavator showing one embodiment of the present invention. It is also a front view. It is an expanded sectional view of an obstacle detection unit. It is an action state figure of an obstacle detection unit. It is a whole block diagram of an obstacle detection apparatus. It is explanatory drawing of a monitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavator body 3 Bulkhead 4 Cutter head 5 Cutter pork 5a Casing 6 Face plate 7 Cutter bit 8 Fish tail cutter 9 Hydraulic jack 10 Copy cutter 11 Ring gear 12 Cutter rotation motor 13 Drive gear 14 Rotary joint 17 Screw conveyor 18 Chamber chamber 19 Jack 20 Gate 22 Propulsion jack 23 Tail seal 24 Back extension 25 Electa 26 Segment adjuster 30 Obstacle detection unit 31 Unit body 32 Hydraulic jack 32a Cylinder 32b Piston 33 Detection bit 34 Metal bearing 35 Non-rotation 36 Contraction line 37 Extension line 38 Solenoid valve 39 Pump 40 Tank 41 Relief Valve 42 Pressure Gauge 43 Pressure Oscillator 44 Flow Meter 45 Rotary Encoder 46 Operation Panel 4 Monitor 47a lamp display unit 47b numerical value display portion 47c graph display unit 47d alarm display unit

Claims (6)

In a tunnel excavator comprising a tubular excavator main body, a propulsion jack that advances the excavator main body, and a cutter head that is supported by the excavator main body so as to be driven to rotate and excavate a face.
In addition to mounting an obstacle detection unit that detects the presence of an obstacle by bringing the detection member into direct contact with the obstacle on the cutter head, a monitoring device for monitoring the detection status by the obstacle detection unit is provided,
The detection member is formed in a semicircular shape in the same shape as the cutter bit mounted on the cutter head, and attached to the tip of a hydraulic jack that extends and contracts in the obstacle detection unit main body and has a cutting function. It is a bit and can be switched between an immersive state and a protruding state as necessary, and when the detection bit contacts an obstacle, the hydraulic jack contracts with an external force to detect the presence of the obstacle.
Tunnel excavator characterized by that. Examples detection situation, the position of the hydraulic jacks, tunnel boring machine according to claim 1, wherein the stroke and oil pressure, characterized in that it is monitored. 3. The tunnel excavator according to claim 1, wherein the obstacle detection unit is provided at a plurality of locations in a radial direction of the cutter head. The obstacle sensing unit tunneling machine according to claim 1, 2 or 3, wherein the provided plurality of locations in the circumferential direction of the cutter head. The tunnel excavation according to claim 1, 2, 3 or 4 , further comprising a control mechanism for stopping the extension of the propulsion jack and the rotation of the cutter head when the obstacle detection unit detects the presence of the obstacle. Machine. The obstacle of the obstacle detection unit according to any one of claims 1 to 5, wherein when the cutting head is cut by advancing the excavator main body with a propulsion jack while rotating the cutter head, the obstacle detection unit mounted on the cutter head is obstructed. A tunnel excavation method characterized in that the presence of an obstacle can be detected by bringing the object into direct contact with the object, and the detection state by the obstacle detection unit is monitored.

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