JP2013047444A - Shield machine and pipeline construction method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shield machine capable of reducing the size of an underground obstacle by shaving the underground obstacle and treating the underground obstacle together with mud by taking the underground obstacle into the shield machine.SOLUTION: In a shield machine 1, a front part of a skin plate 2 is provided with a rotatively-driven cutter plate 3, and a cutter bit 10 for excavation is provided on the front surface of the cutter plate 3. A large number of cutting bits 11 for shaving an underground obstacle are provided on the front surface of the cutter plate 3 in such a manner as to be arranged in a spiral pattern around the rotational axis of the cutter plate 3 as a center. The cutting bits 11 are arranged in such a manner that a cutting edge 11a of the cutting bit 11 protrudes forward with respect to a cutting edge 10b of the cutter bit 10.

Description

  The present invention relates to a shield excavator and a pipe construction method using the shield excavator, and more specifically, if there is an underground obstacle in the path during underground excavation, it is easily removed and excavated without performing ground improvement. The present invention relates to a shield machine and a pipe construction method.

  For example, there are a propulsion method and a shield method for constructing a general pipeline using a shield machine, and the former method involves connecting a propulsion pipe to the rear of the shield machine, pushing the propulsion pipe, The pipes are constructed by sequentially adding propulsion pipes by excavating with a machine, and the latter shield method is connected to the ground by assembling segments to the back of the underground excavation with the shield excavator. It is a construction method to construct a tunnel.

  By the way, when constructing the propulsion method or shield method in urban areas, there are underground obstacles such as sheet piles (sheet piles), steel frames, foundation piles, etc. in the forward path when underground excavation with a shield machine There is a case.

  If such an obstacle exists, the cutter bit of the shield machine will be damaged, resulting in a situation incapable of cutting. If it is found that something is present, stop the shield machine, improve the ground by injecting chemicals into the ground and solidify it, and then dug a cavity manually in the front of the shield machine The obstacle is exposed and the obstacle is removed by gas cutting or the like.

  However, such a processing method by human power is not only dangerous, but also requires a lot of labor and time, and causes the construction cost of pipes and tunnels to rise.

  In order to solve such inconvenience, a roller cutter is arranged at the rear position of the cutter plate in the shield machine, and when there is an obstacle in the ground, this roller cutter is pushed out to the front position of the cutter plate by a hydraulic cylinder, and the roller An obstacle processing shield machine that processes by cutting an obstacle with a cutter has been proposed (see, for example, Patent Document 1).

  In addition, an obstacle processing shield machine has been proposed in which a core boring machine is placed behind the cutter plate inside the shield machine, and the obstacles ahead in the ground are cut and processed by the extension of the core boring machine. (For example, refer to Patent Document 2).

  Aside from these, a high-pressure nozzle is placed in front of the shield machine, and when an obstacle is encountered, the ground improvement material is first jetted from the nozzle to improve the ground, and then the high-pressure fluid is jetted from the nozzle. A processing method for cutting and removing obstacles has also been proposed.

JP-A-8-319796 JP-A-6-336895

By the way, in the above-described conventional obstacle processing shield machine and processing method, both attempt to cut and process obstacles, but there is a limit to downsizing obstacles by cutting.
For this reason, it is practically difficult to take the cut obstacles into the shield machine and treat them with mud, which has become a bottleneck in the practical application of obstacle treatment shield machines and processing methods. However, the current situation is that it relies on human-powered processing methods.

  In addition, it is technically difficult to know in advance the existence of underground obstacles in the construction of conduits and tunnels by shield machine, and in the conventional obstacle treatment shield machine and treatment method described above, It is often the case that the existence of an obstacle is known when the excavation bit comes into contact with the obstacle and the shield machine cannot move forward, and this may cause the excavation bit to be damaged by the obstacle. become.

  Accordingly, the object of the present invention is to solve the above-mentioned problems, by reducing the ground obstacle by cutting it down, taking it into the shield machine and treating it with mud, and the obstacle treatment shield machine Another object of the present invention is to provide a shield machine and a pipe construction method using the shield machine capable of realizing the practical application of the processing method and effectively preventing the occurrence of breakage of the excavation bit due to the underground obstacle.

  In order to solve the problems as described above, the present invention provides a shield machine in which a cutter plate that is rotationally driven is provided at the front portion of the skin plate, and a cutter bit for excavation is provided on the front surface of the cutter plate. A bit for cutting obstacles in the ground is attached to the front surface of the cutter plate.

  The bit may be a cutting bit, and a large number of bits may be provided on the front surface of the cutter plate in a spiral arrangement centering on the rotation axis of the cutter plate.

  The cutting bit comprises a support base fixed to the cutter plate and a plurality of cemented carbide tips attached to the support base so as to be swingable. Each carbide tip has a cutting edge in a direction intersecting the swinging direction. The plurality of carbide tips are arranged in a stepped arrangement along the swing direction, and the cutting bit is rotated on the front surface of the cutter plate so that the swing direction of the carbide tip is rotated by the cutter plate. It can be fixed in an arrangement along the direction.

  The above bit uses a roller bit, and a plurality of roller bits are attached to the front surface of the cutter plate in such a manner that the rotation direction of the roller bit is along the rotation direction of the cutter plate, and the plurality of roller bits are positioned in the radial direction of the cutter plate. It is possible to adopt a structure with a different arrangement.

  The roller bit is formed in a gear shape in which a large number of linear cutting edges along the axial direction are provided at regular intervals in the circumferential direction, and a spiral groove is formed on the outer peripheral surface of the roller bit so as to divide each cutting edge. It may be provided.

  The bit may be arranged such that the bit located at the center of the cutter plate is located at the forefront, and the bit located at the outer peripheral portion is located at the rear.

  The above bit uses both a cutting bit and a roller bit, and this cutting bit is provided with a large number of spiral arrangements around the rotation axis of the cutter plate on the front surface of the cutter plate. A plurality of roller bits are mounted on the entire surface of the cutter plate in such a manner that the rotation direction is along the rotation direction of the cutter plate and the position is different in the radial direction of the cutter plate. ) The cutting edge has a shape in which a plurality of cutting edges are arranged in parallel in the axial direction, and the roller bit, cutting bit, and cutter bit have a forward protruding amount of the cutting edge of the roller bit> a protruding amount of the cutting edge of the cutting bit> a forward protruding amount of the cutting edge of the cutter bit It is preferable to arrange so as to be.

  The pipe construction method uses one of the shield machines described above, and if there are underground obstacles in the course of underground excavation, this is cut by a bit and taken into the shield machine. It is a thing.

  Here, the cutter plate of the shield machine is provided with a center bit for excavation at the front of the center portion and a cutter bit for excavation at least at the outer peripheral portion, and excavates the natural ground by rotating the cutter plate by a motor. The excavated material is taken into the chamber disposed at the rear of the cutter plate from the opening provided in the cutter plate.

  The bit can adopt either a rocking cutting bit, a fixed cutting bit, or a roller bit. In the case of a rocking cutting bit, a plurality of carbide tips are symmetrical on both sides in the rocking direction. Since the rocking direction is fixed with respect to the cutter plate along the rotation direction, the cutting function can be obtained by rotating the cutter plate in any direction, and a plurality of carbide tips. By making the cutting edge multi-stage, even if the cutting edge of the first hard tip is worn or damaged, cutting can be continued with the next hard tip.

  In the case of a fixed cutting bit, a plurality of cemented carbide tips are fixed in a symmetrical arrangement at the tip of a long support base along the rotation direction of the cutter plate with the center in the length direction of the support base interposed therebetween. By making the cutting edge of each carbide tip multi-stage, even if the cutting edge of the first hard tip is worn or damaged, cutting can be continued with the hard tip at the next position.

  The roller bit has a gear-like structure, and a plurality of the roller bits are rotatably attached to the front surface of the cutter plate, and are rotated by revolution by the rotation of the cutter plate in a state of receiving thrust and contacting an obstacle. The obstacle will be sharpened.

  According to the present invention, since the bit for cutting the obstacle in the ground is attached to the front surface of the cutter plate in the shield machine, the obstacle located in the course when the pipeline is constructed by the shield machine. Can be removed by cutting with a bit, and the obstacle becomes a small cut by shaving, and the obstacle can be taken into the shield machine together with the excavated earth and sand by downsizing the obstacle as such a small cut Therefore, the removal and processing of the obstacle can be automatically performed without stopping the shield machine, and the safety and work efficiency can be improved as compared with the processing of the obstacle by human power.

  In addition, by arranging the cutting bit blade edge to be the same or forwardly protruding with respect to the cutting edge of the cutter bit, the cutting bit comes into contact with the obstacle in the ground at the time of excavation by the shield machine, and cutting is performed. The cutter bit can be prevented from being damaged by the obstacle, and the excavation can be continued continuously even if the existence of the underground obstacle cannot be known in advance.

  Furthermore, in a cutting bit, if a plurality of carbide tips are arranged so that the cutting edges are arranged in a stepped shape, if the first carbide tip is worn or damaged, the next carbide tip can be used to remove obstacles. Cutting can be performed, and the working efficiency can be improved by reducing the replacement frequency of the cutting bit.

By using both a cutting bit and a roller bit, and the amount of forward protrusion of the cutting edge of the roller bit is larger than the amount of forward protruding of the cutting edge of the cutting bit, the arcuate cutting edge first appears in the axial direction on the obstacle in the path. It is possible to insert parallel streak grooves with the parallel roller bits and then scrape the remainder of the obstacle between the streak grooves with the cutting bit.
Thus, by cutting the obstacle stepwise, it is possible to prevent a large burden on the bit during cutting, and it is possible to suppress breakage and wear of the bit. In addition, inconveniences such as the bit biting into the obstacle and the entire shield machine rolling can be solved.

Longitudinal front view with a part of the entire structure showing the first embodiment of the shield machine according to the present invention using an oscillating cutting bit. 1 is an enlarged side view taken along arrow II-II in FIG. 1 showing the arrangement shape of the oscillating cutting bits as seen from the tip of the shield machine. 1 is an enlarged vertical side view taken along arrow III-III in FIG. The perspective view which shows partially the arrangement state of the rocking-type cutting bit attached to the cutter board in a shield machine (A) is a perspective view showing the external shape of a rocking-type cutting bit, (b) is a vertical front view of the rocking-type cutting bit, and (c) is a vertical side view of the same. (A) is a cross-sectional plan view showing a cutting state of a sheet pile that is an underground obstacle by a carbide tip of a rocking cutting bit, and (b) is a first carbide tip of the rocking cutting bit. Cross-sectional plan view showing the cutting state of the sheet pile with the second cemented carbide tip when damaged Longitudinal front view of the overall structure showing a second embodiment of a shield machine according to the present invention using a fixed cutting bit An enlarged cross-sectional plan view showing the cutting state of a sheet pile, which is an underground obstacle, with a cemented carbide bit of a fixed cutting bit Side view showing the arrangement of fixed cutting bits as seen from the tip of the shield machine (A) is a perspective view of a fixed cutting bit, (b) is a cross-sectional plan view of the same. Longitudinal front view of the overall structure showing a third embodiment of a shield machine according to the present invention using a roller bit An enlarged cross-sectional plan view showing the cutting state of a sheet pile that is an underground obstacle by a roller bit Side view showing the arrangement of roller bits as seen from the tip of the shield machine (A) is a perspective view of a roller bit, (b) is the same plan view Longitudinal front view of the overall structure showing a fourth embodiment of a shield machine according to the present invention using both a cutting bit and a roller bit Enlarged longitudinal front view of the main part of the shield machine Side view showing the arrangement of cutting bits and roller bits as seen from the tip of the shield machine (A) And (b) is the expanded cross-sectional top view which shows the stepwise cutting state of the sheet pile which is an underground obstruction by a cutting bit and a roller bit, (c) is a perspective view of a cutting bit.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows the overall structure of a shield machine 1 according to the present invention, wherein a disc-shaped cutter plate 3 is attached to a front portion of a cylindrical skin plate 2 and attached to a center shaft 5 supported by a partition wall 4. The cutter plate 3 is rotationally driven by a motor 6 arranged and interlocked with the center shaft 5, and a chamber 7 for taking in excavated earth and sand is formed between the cutter plate 3 and the partition wall 4, as shown in FIG. 8 and the mud pipe 9 are connected.

  As shown in FIG. 2, a cutter bit 10 for excavation and a number of bits 11 for cutting the underground obstacle A are attached to the front surface of the cutter plate 3, and the cutter bit 10 for excavation is a cutter. Provided in two rows in the radial direction on both sides in the radial direction across the center bit 12 provided at the center of the plate 3, the outermost one slightly protrudes from the outer diameter of the skin plate 2 From the portion of the opening 13 provided in the vicinity of the cutter bit 10 of the cutter plate 3, the ground bit is dug by the cutter bit 10 and the center bit 12 by the rotation of the cutter plate 3 by the motor 6. The excavated material is taken into the chamber 7.

  A large number of the cutting bits 11 are arranged in a spiral shape around the rotation axis of the cutter plate 3 at the positions on both sides of the front surface of the cutter plate 3 that are substantially semicircular except the portion of the cutter bit 10. As shown in FIG. 1, the cutting edge of the bit 11 protrudes forward with respect to the cutting edge 10 b of the cutter bit 10.

  1 to 6 show a first embodiment of a shield machine 1 using a rocking cutting bit 11A as the bit 11. As shown in FIG.

  FIG. 3 shows the structure of the oscillating cutting bit 11A. A bifurcated support base 14 fixed to the cutter plate 3 and a plurality of carbides attached to the support base 14 so as to be swingable by a shaft 15. Each carbide tip 16 has a cutting edge 11a in a direction intersecting with the swinging direction, and the plurality of carbide tips 16 have a stepped arrangement of the cutting edges 11a along the swinging direction. In the illustrated case, the two carbide chips 16a and 16b are arranged symmetrically on both sides of the shaft 15, and the cutting bit 11 is made of a cutter plate 3 as shown in FIG. The rocking direction of the cemented carbide chip 16 is fixed to the front surface of the cutter plate 3 along the rotational direction of the cutter plate 3.

  As shown in FIG. 2, the large number of oscillating cutting bits 11 </ b> A described above are fixed to the front surface of the cutter plate 3 on the condition that the oscillating direction is along the rotational direction of the cutter plate 3. From the position near the outer periphery of the center bit 12 to the outer periphery of the cutter plate 3 around the rotation axis of the plate 3, the spiral arrangement is a combination of two spirals.

  In the spiral arrangement of each oscillating cutting bit 11 </ b> A, the oscillating cutting bit 11 </ b> A in a positional relationship adjacent to the front and rear along the rotation direction of the cutter plate 3 is cut by the cutting edge 11 a of the carbide tip 16. Are arranged so that the side edges in the width direction coincide with each other but partially wrap, and the distance along the rotation direction of the oscillating cutting bit 11A and the spiral arrangement are within the diameter range of the cutter plate 3. The cutting function is obtained on the entire surface of the shield machine 1 so that no uncut residue of the obstacle A within the excavation range of the shield machine 1 occurs, and the oscillating cutting bit 11A is thus cut into the cutter. By randomly disposing the front surface of the plate 3, it is possible to reduce the load on the shield machine 1 when the obstacle A is cut.

  When the cutting edge 11a of the cemented carbide tip 16 abuts against the obstacle A during the excavation of the shield machine 1, the swing type cutting bit 11A rotates the cutter plate 3 with the width of the cutting edge 11a. Even if the obstacle A is steel, wire, or concrete, the scraped part will be thin and narrow, so it will be easily divided and downsized together with the excavated earth and sand. It can take in into the chamber 7 from the part of the opening 13 of the cutter board 3, and can take out on the ground by normal mud processing.

  In addition, when the obstacle A is hard like a steel material such as a sheet pile, it takes a certain amount of time to scrape off with the carbide tip 16, but the work time required for the construction of the above-described processing method by human power, That is, the operation of the shield machine is stopped, the time for injecting and solidifying the chemical into the ground, and the time for exposing the obstacle by manually digging a cavity in the front part of the shield machine, gas cutting this obstacle, etc. If the total time of removal is sufficient, it can be processed sufficiently, and there is no problem that the work time is excessively long.

  The shield machine 1 shown in FIG. 1 is a mud-type propulsion method in which a propulsion pipe 17 is connected to the rear end of the skin plate 2 and a plurality of direction correcting jacks 18 are provided in a part where the skin plate 2 is separated. However, it may be used for a semi-shielding method in which a space for assembling segments is provided at the rear part of the skin plate 2 and a propulsion jack is provided inside the skin plate 2.

  7 to 10 show a second embodiment of the shield machine 1 using the fixed cutting bit 11B as the bit 11. As shown in FIG. In addition, it replaces with description by attaching | subjecting the same code | symbol to the same part as above-mentioned 1st Embodiment. The same applies to the following embodiments.

  As shown in FIGS. 9 and 10, the fixed cutting bit 11 </ b> B sandwiches the center of the length of the support base 21 at the tip of the long support base 21 so as to draw an arc along the rotation direction of the cutter plate 3. The plurality of carbide tips 16 are fixed in a symmetrical arrangement, and the cutting edge 11a of each carbide tip 16 is arranged in multiple stages so that the center portion is the highest and becomes lower toward both ends.

  By doing in this way, even if the cutting edge 11a of the first hard tip 16 is worn or damaged, cutting can be continued with the carbide tip 16 at the next position.

  As shown in FIG. 9, the fixed cutting bit 11 </ b> B is fixed to the front surface of the cutter plate 3 in a single spiral arrangement around the rotation axis of the cutter plate 3, and the cutter plate 3 is fixed from the outer periphery. By adopting a conical cross-sectional shape that rises toward the center, the arrangement of the cutting edges 11a of the cemented carbide tips 16 in the all-fixed cutting bit 11B is such that the center part protrudes most forward in the propulsion direction, and on the outer periphery. The conical arrangement is located at the rear as the object is located, and the obstacle is cut from the center of the pipeline, and the obstacle is directed from the center of the pipeline toward the outer circumference so as not to reduce the holding power of the obstacle. Cutting is performed, and the opening by cutting is expanded from the center to the outer periphery.

  Such an arrangement of the cutting edges 11a of the fixed cutting bit 11B having a conical arrangement in which the central portion protrudes most forward is naturally applicable to the first embodiment described above.

  In the second embodiment described above, the excavating cutter bit 10 is a gauge bit 10a fixed at a position near the outer periphery of the cutter plate 3, and in the case of FIG. The cutting bits 11 that are long in the radial direction are fixed at positions on both sides.

  FIGS. 11 to 14 show a third embodiment of the shield machine 1 using a roller bit 11 </ b> C as the bit 11.

  The roller bit 11C is formed in a gear shape in which a large number of linear cutting edges 11a along the axial direction are provided in the circumferential direction on the outer circumferential surface of the circular shaft body 22 made of a super hard material, as shown in FIG. A plurality of roller bits 11C are mounted on the front surface of the cutter plate 3 formed in a conical cross-sectional shape that rises toward the center so as to be rotatable on the radial center line passing through the center of rotation. As described above, the number and mounting positions of the roller bits 11C on both sides along the radial direction across the rotation center of the cutter plate 3 are made different so that the entire surface can be cut by the rotation of the cutter plate 3, and each roller The bit 11 </ b> C is arranged such that the cutting edge 11 a follows the front cone of the cutter plate 3.

  In addition, the cutting roller bits 11C having the maximum diameter are attached in two positions on the outer periphery of the front surface of the cutter plate 3 at right angles to the above-described series of roller bits 11C arranged in series. A cutter bit 10 is provided at an inner position of the maximum diameter cutting roller bit.

  As shown in FIG. 14, the roller bit 11 </ b> C is formed in a gear shape in which a large number of linear cutting edges 11 a along the axial direction are provided at regular intervals in the circumferential direction on the outer peripheral surface. By providing a spiral groove 23 along the circumferential direction on the outer peripheral surface and dividing each blade edge 11a, the cutting ability to the obstacle is improved by improving the biting property of the edge portion by dividing each blade edge 11a. A material whose cutting efficiency is increased can be used.

FIGS. 15 to 18 show a fourth embodiment of the shield machine 1 in which the fixed cutting bit 11B and the roller bit 11C are used in combination with the bit 11. FIG.
Hereinafter, detailed description of the same configurations as those in the above embodiments will be omitted.

The fixed cutting bit 11B has a structure similar to that of the second embodiment in which the cemented carbide chip 16 is fixed to the support base 21 (see FIG. 18C).
The cutting edge (end face) 11a of the cemented carbide tip 16 is an acute angle that is not chamfered, and has a shape in which the improvement of cutting performance is given priority over the risk of breakage.
As shown in FIG. 17, it is fixed to the front surface of the cutter plate 3 in a substantially spiral arrangement around the rotation axis of the cutter plate 3, and a cutting function can be obtained on the entire surface within the diameter range of the cutter plate 3. It has become.
In place of the fixed cutting bit 11B, a swinging cutting bit 11A similar to that of the first embodiment can be used.

The roller bit 11 </ b> C has an arcuate (annular) cutting edge 11 a formed on the outer peripheral surface of the circular shaft body 22, and many of the cutting edges 11 a are arranged in parallel in the axial direction of the circular shaft body 22.
Each roller bit 11 </ b> C is attached to the cutter plate 3 so that the axis of the circular shaft body 22 coincides with the radial direction of the cutter plate 3. For this reason, the roller bit 11 </ b> C rotates along the rotation direction of the cutter plate 3.
Further, as shown in FIG. 17, the roller bit 11 </ b> C is arranged so that the position of the cutter plate 3 is different in the radial direction and does not overlap with the fixed cutting bit 11 </ b> B. Can be done.

  As shown in FIGS. 15 and 16, the cutter plate 3 is formed in a conical cross-sectional shape that increases from the outer peripheral edge toward the center, and the cutting edge 11 a of each fixed cutting bit 11 </ b> B and each roller bit 11 </ b> C. The blade edge 11a is arranged substantially along the conical shape on the front surface of the cutter plate 3.

Furthermore, as shown in FIG. 16, when comparing the height of the cutter bit 10, the fixed cutting bit 11B, and the roller bit 11C that are substantially equidistant from the center of the cutter plate 3, the blade edge 11a of the roller bit 11C protrudes most forward and is fixed. The cutting edge 11a of the type cutting bit 11B follows this, and the cutting edge of the cutter bit 10 is located at the rearmost position.
Therefore, when cutting an obstacle with the bit 11, the roller bit 11C first comes into contact with the obstacle and cuts it, and then the fixed cutting bit 11B comes into contact with the obstacle and cuts it. .

  Next, the construction method of the pipeline construction method according to the present invention will be described mainly using the shield machine 1 of the first embodiment described above.

  By rotating the cutter plate 3 of the shield machine 1 inserted into the ground and simultaneously applying thrust to the shield machine 1, the excavation cutter bit 10 and the cutting bit 11 are rotated to excavate the ground. The excavated soil is excavated by taking it into the chamber 7 from the opening 13, and a pipe line or tunnel by adding a propelling pipe 17 or a segment or connecting pipe or tunnel to the rear of the shield machine 1 Will build.

  When the shield machine 1 is excavated, if there are underground obstacles A such as sheet piles, steel frames, and foundation piles on the path, the cutting bit 11 comes into contact with the obstacles and the cutter plate 3 is rotating. At the same time, since the thrust in the forward direction is given to the shield machine 1, the cutting bit 11 cuts the obstacle A along the rotational direction of the cutter plate 3 with the cutting edge 11 a of the carbide tip 16.

FIG. 6A shows the cutting state of the cutting bit 11 when the underground obstacle A is a sheet pile, and the cutting bit 11 that can swing along the rotation direction a of the cutter plate 3 has a rotation direction. When the cutting edge 11a of the first cemented carbide tip 16a located in front of a comes into contact with the sheet pile, the cutting bit 11 tilts so that the cutting edge 11a bites into the sheet pile, and the surface of the sheet pile is made of the carbide chip. Sharpen with the width of the cutting edge 11a of 16a.

  Each cutting bit 11 is fixed to the front surface of the cutter plate 3 in two spiral arrangements, and the cutting bits 11 that are adjacent to each other along the rotation direction a of the cutter plate 3 are front and rear. Since the side edges in the width direction of the cutting width by the cutting edge 11a of the hard tip 16 coincide with each other but are arranged so as to partially wrap, a range corresponding to the outer diameter of the shield machine 1 with respect to the obstacle A is set. Can be sharpened.

  At this time, since the cutting edge 11a of the cemented carbide tip 16 in the cutting bit 11 is disposed so as to protrude forward from the excavating cutter bit 10, the excavating cutter bit 10 is damaged by coming into contact with an obstacle. There is no such thing.

  Since each of the cutting bits 11 has a structure in which a plurality of carbide tips 16 are arranged along the rotation direction a of the cutter plate 3, as shown in FIG. When 16a is worn or damaged, cutting can be continued by the second carbide tip 16b, and the carbide tip 16 is arranged symmetrically on both sides with the shaft 15 in between. When the carbide tip 16 on the side is worn or damaged, cutting can be continued with the carbide tip 16 on the other side by rotating the cutter plate 3 in the reverse direction.

  As described above, by continuing the rotation of the cutter plate 3 and the application of thrust to the shield machine 1, the cutting edge 11a of each cemented carbide tip 16 has the obstacle A within a range commensurate with the outer diameter of the shield machine 1. The object A that has been scraped off is thin and narrow, and is cut into small pieces by kneading with the excavated earth and sand. 7 can be taken in, and by using the existing mud discharge mechanism, both mud and soil can be taken out and processed.

  In this way, if the obstacle A is scraped off within a range commensurate with the outer diameter of the shield machine 1 while the shield machine 1 is continuously excavated, it is only necessary to construct a pipeline as a normal machine. Even if A exists, a pipeline can be constructed without interrupting excavation.

  In the construction of the pipe construction method described above, when the shield machine 1 of the second embodiment is used, when an underground obstacle is encountered, it is provided on the front surface of the cutter plate 3 by applying rotation and thrust. The obstacle is cut by the fixed cutting bit 11B. Since the fixed cutting bit 11B is arranged in a conical shape, the obstacle starts to be cut from the center of the pipe. By extending the cutting range from the outer periphery to the outer periphery, it is possible to prevent the holding power of the obstacles from being reduced, and to excavate so that the natural ground does not collapse.

  In addition, when the shield machine 1 of the third embodiment is used, the bit 11 is a roller bit 11C, so when encountering an obstacle in the ground, the roller bit 11C provided with rotation and thrust is It rotates while revolving, and the obstacle 11 is efficiently cut by the cutting edge 11a due to the twisting action accompanying the change in the rotation direction of the roller bit 11C.

Furthermore, when the shield machine 1 of the fourth embodiment is used, when the obstacle A in the ground is encountered, the blade edge 11a of the roller bit 11C first contacts the obstacle from the relationship of the protrusion amount of the blade edge described above. To do. Then, as shown in FIG. 18A, the obstacle is scraped off in a state where the streak-like grooves G are arranged in parallel by the arcuate cutting edge 11a arranged in parallel in the axial direction of the circular shaft body 22 of the roller bit 11C.
Next, the cutting edge 11a of the fixed cutting bit 11B comes into contact with the obstacle A, and as shown in FIG. 18B, the remaining portion between the streak-like grooves G formed by the roller bit 11C of the obstacle is cut off.
Thus, since the obstacle A is cut stepwise, the load applied to the bit 11 at the time of cutting can be reduced, and its wear can be prevented. In particular, by forming the streak-like grooves G parallel to each other by the roller bit 11C in the obstacle A, the obstacle is crushed and cut, so that the subsequent cutting with the fixed cutting bit 11B can be performed smoothly.

  In this invention, since the underground obstacle is cut with the rocking cutting bit 11A, the fixed cutting bit 11B or the roller bit 11C, even if the underground obstacle is made of metal or concrete, The resulting cut object is narrow and thin, and such a cut object can be discharged to the ground together with the excavated soil.

DESCRIPTION OF SYMBOLS 1 Shield machine 2 Skin plate 3 Cutter plate 4 Bulkhead 5 Center shaft 6 Motor 7 Chamber 8 Mud pipe 9 Mud pipe 10 Drilling cutter bit 11 Cutting bit 11A Oscillating cutting bit 11B Fixed cutting bit 11C Roller bit 12 Center bit 13 Opening 14 Support base 15 Shaft 16 Carbide tip 17 Propulsion pipe 18 Direction correction jack 21 Support base 22 Circular shaft body 23 Spiral groove A Obstacle G Obstacle groove

Claims (8)

  In a shield machine with a cutter plate that is rotationally driven at the front of the skin plate and provided with a cutter bit for excavation on the front surface of the cutter plate, an obstacle in the ground is cut on the front surface of the cutter plate. A shield machine that is equipped with a bit for the purpose.   2. The shield digging according to claim 1, wherein a plurality of the bits are provided in a spiral arrangement centering on the rotation axis of the cutter plate on the front surface of the cutter plate using a cutting bit. Machine.   The cutting bit comprises a support base fixed to the cutter plate and a plurality of cemented carbide tips attached to the support base so as to be swingable. Each carbide tip has a cutting edge in a direction intersecting the swinging direction. The plurality of carbide tips are arranged in a stepped arrangement along the swing direction, and the cutting bit is rotated on the front surface of the cutter plate so that the swing direction of the carbide tip is rotated by the cutter plate. The shield machine according to claim 2, wherein the shield machine is fixed in an arrangement along the direction.   The above bit uses a roller bit, and a plurality of roller bits are attached to the front surface of the cutter plate in such a manner that the rotation direction of the roller bit is along the rotation direction of the cutter plate, and the plurality of roller bits are positioned in the radial direction of the cutter plate. The shield machine according to claim 1, wherein the shield machine is arranged differently.   The roller bit is formed in a gear shape in which a large number of linear cutting edges along the axial direction are provided at regular intervals in the circumferential direction, and a spiral groove is formed on the outer peripheral surface of the roller bit so as to divide each cutting edge. The shield machine according to claim 4, wherein the shield machine is provided.   6. The bit according to any one of claims 1 to 5, characterized in that the bit located at the center of the cutter plate is located at the forefront, and the bit located at the outer periphery is located at the rear. The shield machine of crab. The above bit uses cutting bit and roller bit together,
A large number of the cutting bids are provided on the front surface of the cutter plate in a spiral arrangement around the rotation axis of the cutter plate,
A plurality of roller bits are attached to the entire surface of the cutter plate in an arrangement in which the rotation direction is along the rotation direction of the cutter plate and the position is different in the radial direction of the cutter plate,
The roller bit shall have a plurality of arcuate cutting edges along the circumferential direction in parallel in the axial direction,
The shield machine according to claim 1, wherein the roller bit, the cutting bit, and the cutter bit are arranged so as to satisfy the following formula.
Amount of forward protrusion of the cutting edge of the roller bit> Amount of forward protrusion of the cutting edge of the cutting bit> Amount of forward protrusion of the cutting edge of the cutter bit   A pipe which uses the shield machine according to any one of claims 1 to 7 and cuts a bit with a bit and takes it into the shield machine when there is an underground obstacle in the course of underground drilling. Road construction method.

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