Shield tunnel boring machine

Abstract: A shield tunnel boring machine having a parallel link excavator includes excess excavating cutters joined to the excavator as divided into a plurality of steps, the excess excavating cutters of the respective steps being coupled to separate ones of jacks respectively actuatable as controlled independently of each other, for allowing the position of the machine to be effectively controlled to be able to quickly correct any rolling.

Description: BACKGROUND OF THE INVENTION This invention relates to shield tunnel boring machines comprising a parallel link excavator which performs a rotary motion of parallel link arrangement, and an excess excavator disposed to externally enclose at least part of the parallel link excavator. DESCRIPTION OF RELATED ART Recently, the shield tunnel boring machines having the parallel link excavator have been provided, in place of such shield tunnel boring excavator provided with a plurality of radially extending cutter spokes with many cutter bits mounted thereon as been disclosed in U.S. Patent No. 4,607,889 to Hagimoto et al. and assigned to the present assignee. JP-4115095, assigned to the present assignee, shows an excess excavating cutter comprising a single vertical cutter spoke of a rectangular parallel link excavator. The cutter spoke is moved laterally by a jack. The tunnel boring machine is provided for the purpose of boring a curved tunnel, and it is sufficient to provide the excess excavating cutter only on a predetermined side on which the bored tunnel is to be curved. If the underground structure is unstable or complicated, the curvature of the boring direction may easily be caused to fluctuate to cause a rolling in leftward or rightward direction of the boring machine. According to the shield tunnel boring machine having the parallel link excavator of the kind referred to, it is made possible to render operational mode of the cutter spokes to be more various than in the case of the cutter spokes extending merely radially, and cutting action attainable by means of the cutter bits mounted on the cutter spokes can be eventually improved to a remarkable extent. In the shield tunnel boring machine of the kind referred to, on the other hand, there has been provided one having excess excavating cutters in addition to the parallel link excavator, but an excess excavation executed for the purpose of correcting a rolling occurred during the tunnel boring operation of the shied tunnel boring machine in particular has not reached as yet a sufficiently satisfiable level, and it has been demanded that a shield tunnel boring machine capable of realizing an effective excess excavation and of performing a position control in smooth manner to have the rolling effectively corrected is provided. SUMMARY OF THE INVENTION A primary object of the present invention is, therefore, to provide a shield tunnel boring machine which has eliminated the foregoing problem and is capable of executing the position control in smooth manner with the excess excavation effectively realized to quickly correct the rolling and, in addition, being usefully employable for constructing a tunnel in curved aspect. According to the present invention, the above object can be realized by means of a shield tunnel boring machine wherein a parallel link excavator including tunnel-face cutters consisting of cutter spokes to which many cutter bits are mounted is additionally provided with excess excavating cutters consisting of cutter spokes to which many cutter bits are mounted for enabling an excess excavation to be executed during the excavation at the tunnel face, characterized in that the excess excavating cutters are divided into a plurality of steps, the excess excavating cutters of the respective steps being coupled mutually separately to jacks which are coupled to means for adjusting mutually independently the excess excavation rate of the cutters at the respective steps. Other objects and advantages of the present invention shall be made clear in the following description of the invention detailed with reference to preferred embodiments shown in accompanying drawings. BRIEF EXPLANATION OF THE DRAWINGS FIGURE 1 is a front view of the shield tunnel boring machine in a first embodiment according to the present invention; FIG. 2 is a fragmentary front view as magnified of a major part of the shield tunnel boring machine of FIG. 1; FIG. 3 is a front view of the shield tunnel boring machine in a second embodiment according to the present invention; FIG. 4 is a fragmentary front view as magnified of a major part of the machine of FIG. 3; FIG. 5 is a fragmentary sectioned view as magnified of another major part in the machine of FIG. 3; FIG. 6 is an explanatory view for the operation of the machine of FIG. 3; and FIG. 7 is a front view of the shield tunnel boring machine in a third embodiment according to the present invention. While the present invention shall be described with reference to the respective embodiments shown in the accompanying drawings, it should be appreciated that the intention is not to limit the invention only to these embodiments shown but rather to include all alterations, modifications and equivalent arrangements possible within the scope of appended claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring here to FIG. 1, there is shown a first embodiment of the shield tunnel boring machine according to the present invention, in which the shield tunnel boring machine comprises a shield cylinder 1, a parallel link excavator 2, a mud discharger 11, and two sets of excess excavating cutters 12-14 and 15-17 disposed symmetrically on both sides of the parallel link excavator 2 with respect to rotary axis of the excavator 2, so as to externally enclose at least part of the excavator 2. In the present embodiment, the shield cylinder 1 is formed to have a cross section substantially of such squarish ellipse or rounded rectangular as a track of track-and-field events in its outline. The parallel link excavator 2 is constituted by a motive rotor 3, tunnel-face cutters 4, a large number of cutter bits 5 mounted to the cutters 4, follower rotors 6a-6h, and support shafts 7a-7d coupling between the cutters 4 and the respective follower rotors 6a-6h. The motive rotor 3 is coupled through reduction gears to an optimum rotary driving source mounted to an inner bulkhead of the shield cylinder 1. For these bulkhead, rotary driving source and reduction gears, it is possible to employ any known ones, and they are omitted from the drawings. The tunnel-face cutters 4 are constituted by a main part formed with a lattice formation of a plurality of horizontal cutter spokes 4a-4d arranged as mutually separated in vertical directions and a plurality of vertical cutter spokes 4e-4g arranged as mutually separated in horizontal directions, as well as a plurality of upper vertical cutter spokes 4h disposed on upper side of the topmost horizontal cutter spoke 4a as mutually separated at regular intervals, and a plurality of lower vertical cutter spokes 4i disposed on lower side of the lowermost horizontal cutter spoke 4d as mutually separated at regular intervals. In a range where the cutter device 4 is disposed, a muddying material jet 8 and a mud pressure gauge 10 are provided respectively one or more as occasion demands. Further, the large number of the cutter bits 5 are provided on front side face of the respective cutter spokes 4a-4i of the cutters 4 respectively at optimum intervals. The follower rotors 6a-6h are provided in two sets, each of which sets including four rotors 6a-6d and 6e-6h to be thus eight in total and being arranged in vertical direction on both lateral sides of the parallel link excavator 2 as viewed from the front side of FIG. 1, while the respective follower rotors 6a-6d and 6e-6h are coupled through such a power transmission system as a gear train (not which) to the motive rotor 3 and are made rotatable about "O" point as the rotary center mutually in synchronism and in the same direction. Kneading blades 9 for mixing excavated ground formation with a muddying material jetted out of the muddying material jets 8 are provided to all or part of the follower rotors 6a. Further, the support shafts 7a-7d are respectively mounted to an eccentric position of corresponding one of the follower rotors 6a, 6d, 6e and 6h. Here, the respective support shafts 7a-7d are so constituted as to realize a support which allows the parallel link excavator 2 to rotate as a whole within the shield cylinder 1 in the operational aspect of the parallel link, in cooperation with each other of the respective support shafts 7a-7d. The mud discharger 11 is provided in the shield cylinder 1 to open its mud inlet port in a tunnel face chamber (not shown) defined at front end of the shield tunnel boring machine between the tunnel face and the bulkhead, in which chamber the excavator 2 is provided. Further, the excess excavating cutters 12-14 and 15-17 on both lateral sides of the parallel link excavator 2 are provided as divided into a plurality of steps in the front side view of FIG. 1. The respective cutters 12-14 and 15-17 comprise cutter spokes 18a-18c and 18d-18f of both side rows, upward cutter spokes 18g at top position of the topmost side cutter spokes 18a and 18d, downward cutter spokes 18h at lower position of the lowermost side cutter spokes 18c and 18f, a large number of cutter bits 19 mounted to the cutter spokes 18a-18c and 18d-18f vertically oriented and upward and downward cutter spokes 18g and 18h, and jacks 20a-20c and 20d-20f provided in pairs with respect to the respective cutter spokes 18a-18c and 18d-18f, as coupled to an adjusting means (not shown) to be respectively mutually independently controllable. With this arrangement, the amount of excess excavation by means of the respective cutters 12-14 and 15-17 can be independently adjusted through expansion and contraction of the respective pairs of the jacks 20a-20c and 20d-20f. Next, the operation of the shield tunnel boring machine in the first embodiment constituted as has been described shall be explained. In boring a tunnel through a ground, the parallel link excavator 2 is actuated with an rotary output of the motive rotor 3, the eight follower rotors 6a-6d and 6e-6h are thereby driven through such power transmission system as the gear train to rotate mutually in synchronism and in the same direction. At this time, with the interposition of the support shafts 7a-7d mounted to the eccentric position of the follower rotors 6a, 6d and 6e, 6h, the cutter spokes 4a-4f of the cutters 4 execute the parallel link rotation in a predetermined direction while maintaining the parallel link coupling state, and the tunnel face ground is excavated by the number of the cutter bits 5 mounted to the cutters 4. At the same time, the excess excavating cutters 12-14 and 15-17 on the both lateral sides are caused to follow the motion of the parallel link excavator 2 to be thereby rotated, and the excess excavation can be attained in response to any demand with respect to the tunnel face ground by means of the number of the cutter bits 19. After the excavation of the tunnel face ground as has been referred to, a muddying material is jetted to excavated ground formation from the muddying material jet 8 as occasion demands, and the excavated ground formation is mixed with the muddying material by means of the kneading blades 9, to have the formation provided with a certain viscosity to become muddy, so that the discharge out of the shield tunnel boring machine will be easier. Further, the mud pressure within the tunnel face chamber at the front end of the shield tunnel boring machine is monitored by the mud pressure gauge 10, and the mud of the excavated ground formation is sequentially discharged by means of the mud discharger 11, while maintaining the mud pressure within the tunnel face chamber at a level capable of preventing the tunnel face from collapsing. After the excavation of the tunnel face ground for a predetermined zone, propelling jacks of general purpose type and incorporated in the shield cylinder 1 are expanded for a proper extent, and the shield cylinder 1 is propelled forward. With the foregoing operation sequentially executed by the shield tunnel boring machine actuated and propelled forward, the tunnel is bored while peripheral wall of the tunnel is covered with any known measure. In an event where a rolling has occurred in the shield tunnel boring machine during the tunnel boring operation, on the other hand, such position control of the shield tunnel boring machine as will be referred to in the following is executed, and the rolling can be optimumly corrected. That is, in an event where the rolling has taken place in leftward direction with respect the tunnel face, for example, the excess excavation rate of the excess excavating cutters 15 at upper right side and of the excess excavating cutters 14 at lower left side is made the largest by means of the jacks 20d,20d and 20c,20c in pairs as in FIG. 2, while the excess excavating rate of the excess excavating cutters 16 at middle right side and of the excess excavating cutters 15 at lower righ tside by means of the jacks 20e,20e and 20f,20f is gradually reduced stepwise, and the excess excavating rate of the excess excavating cutters 13 at middle left side and of the excess excavating cutters 12 at upper left side by means of the jacks 20b,20b and 20a,20a is gradually reduced stepwise, to execute the excess excavation under the control of the jack adjusting means. The position of the shield tunnel boring machine is thereby controlled onto the right side, and the leftward rolling can be corrected. In the case when the rolling of the shield tunnel boring machine takes place rightward in respect of the tunnel face, to the contrary, the excess excavation rate of the excess excavating cutters 12 at upper left side and of the excess excavating cutters 17 at lower right side are made to be the largest by means of the jacks 20a,20a and 20f,20f, while the excess excavation rate of the excess excavating cutters 13 at middle left side and of the excess excavating cutters 14 at lower left side is gradually reduced stepwide by means of the jacks 20b,20b and 20c,20c, the excess excavation rate of the excess excavating cutters 16 at middle right side and of the excess excavating cutters 15 at upper right side is gradually reduced stepwise by means of the jacks 20e,20e and 20d,20d, and the excess excavation is thus executed, whereby the position of the shield tunnel boring machine is controlled to be leftward so as to correct the rightward rolling. With the above operation performed, it is enabled to effectively realize the tunnel boring while reliably executing the position control of the shield tunnel boring machine even in the event where the rolling of the machine takes place either leftward or rightward, irrespective of the extent of the rolling. It should be further appreciated that the above arrangement for the position control is effectively applicable to the boring of curved tunnel. In FIGS. 3 to 6, there is shown a second embodiment of the shield tunnel boring machine according to the present invention, in which substantially the same constituent members as those in the foregoing embodiment of FIG. 1 are denoted by the same reference numbers. In the present second embodiment, the cutter spokes 18a, 18c, 18d and 18f of the cutters 12, 14, 15 and 17 corresponding to corner parts of the parallel link excavator 2, in the excess excavating cutters 12-17 are formed in an angle shape to be L-shaped. To outer surfaces of these cutter spokes 18a, 18c, 18d and 18f, that is, top and side surfaces of the cutter spokes 18a and 18d as well as the side the lower surfaces of the cutter spokes 18c and 18f, the cutter bits 19 are mounted respectively at optimum intervals. The upper and lower side horizontal cutter spokes 4a and 4d of the cutters 4 are provided respectively with an engaging groove 21 whereas the upper cutter spokes 18a and 18d and lower cutter spokes 18c and 18f are provided respectively with an engaging projection 22 engageable in the groove 21 of the upper and lower cutter spokes 4a and 4d, so that the upper and lower cutter spokes 4a and 4d will be slidably coupled to the upper and lower cutter spokes 18a,18d and 18c,18f. While in this second embodiment it is preferable to form the engaging groove 21 and engaging projection 22 as a dovetail groove and a dovetail, respectively, it is not required to always employ such dovetail joint but possible to adopt any other shape. Further, it is also possible to provide the engaging grooves 21 in the cutter spokes 18a, 18d, 18c and 18f and to form the engaging projections 22 on the side of the upper and lower cutter spokes 4a and 4d of the cutters 4. In the shield tunnel boring machine of this second embodiment, the excess excavating cutters are operated as controlled in a manner described below, in the event where the rolling has taken place during the tunnel boring operation of the shield machine and the position control is to be executed against the rolling. Provided here that the shield tunnel boring machine has involved the rolling in leftward direction with respect to the tunnel face, the excess excavation rate of the lower left side cutters 14 comprising the angle shaped cutter spoke 18c and cutter bits 19 mounted thereto and of the upper right side cutter 15 comprising the angle shaped cutter spoke 18d and cutter bits 19 mounted thereto is adjusted by the jacks 20c,20c and 20d,20d to be the largest, while the excess excavation rate of the cutters 13 and 12 at middle left side and upper left side and of the cutters 16 and 17 at middle right side and lower right side is adjusted by the jacks 20b,20b; 20a,20a; 20e,20e and 20f,20f to be gradually stepwise reduced. At this time, the excess excavation is attained at lower left side part of the tunnel being bored, by means of the cutter bits 19 mounted to the cutter spokes 18c in the upper left side excess excavating cutter 14, and at upper right side part of the tunnel being bored, by means of the cutter bits 19 mounted to the cutter spoke 18d in the upper right side excess excavating cutter 15. Preferably, this excess excavation is carried out in a range 23 of an outline shown by a dotted line in FIG. 6. Therefore, the foregoing position control can be reliably executed in respect of the shield tunnel boring machine. When the shield tunnel boring machine has caused the rightward rolling with respect to the tunnel face, to the contrary, the upper left side excess excavating cutter 12 comprising the angle shaped cutter spoke 18a and cutter bits 19 mounted thereto as well as the lower right side excess excavating cutter 17 comprising the angle shaped cutter spoke 18f and cutter bits 19 mounted thereto are adjusted by the jacks 20a,20a and 20f,20f to be the largest in the excess excavation rate, while the middle and lower left side excess excavating cutters 13 and 14 and the middle and upper right side excess excavating cutters 16 and 15 are so adjusted by the jacks 20b,20b; 20c,20c; 20e,20e and 20d,20d as to be gradually stepwise reduced in the excess excavation rate. Consequently, the excess excavation can be attained at the upper left side part of the tunnel being bored by means of the cutter bits 19 mounted to the cutter spoke 18a in the upper left side excess excavating cutter 12, and at the lower right side part of the tunnel being bored by means of the cutter bits 19 mounted to the cutter spoke 18f in the lower right side excess excavating cutter 17. Also in the present second embodiment as has been described, the shield tunnel boring machine can be optimumly subjected to the position control in the event of the rolling in either side of leftward and rightward, for correcting the rolling. Further, with this position control arrangement utilized, the machine is enabled to readily execute the boring of the curved tunnel. In the present second embodiment, in addition, it is made possible to control the excess excavation rate in smooth manner, by means of a slidable coupling through the engaging groove 21 and projection 22 between the upper left side and right side cutter spokes 4a and 4d of the cutters 4 and the cutter spokes 18a and 18d of the upper left side and right side excess excavating cutters 12 and 15, and by means of a slidable coupling between the lower left side and right side cutter spokes 4c and 4f of the cutters 4 and the cutter spokes 18c and 18f of the lower left side and right side excess excavating cutters 14 and 17. Other constituents and their functions in this second embodiment are substantially the same as those in the foregoing first embodiment. Further, while in the foregoing embodiments the left side and right side excess excavating cutters have been described as being divided into three stages in vertical direction, they are not required to be so limited but may be in two stages or in four or more stages. In FIG. 7, there is shown a third embodiment of the shield tunnel boring machine according to the present invention, in which the constituents performing substantially the same function as those in the foregoing embodiment of FIG. 1 are denoted by the same reference numbers but with a suffix "A" added. In this third embodiment, the parallel link excavator 2A is made to have a hexagonal outline, in which peripheral cutter spokes 4Aa-4Af and inner radial cutter spokes 4Ag-4Al are disposed respectively between adjacent ones of six corners and between each corner part and central part, and the cutters 4A for cutting the tunnel face ground are formed with these cutter spokes 4Aa-4Al. At the respective corners of the hexagonal shape, the follower rotors 6Aa-6Af are provided, and three of the cutter spokes jointed to the respective corner parts are pivoted thereto with the respective support shafts 7Aa-7Af. The cutter spokes 18Aa-18Ad forming the excess excavating cutters 12A surrounding the cutters 4A for the tunnel face are provided to be respectively arcuate, so as to form a circular shape in the outline as a whole. Between the cutters 4A for the tunnel face and the excess excavating cutters 12A, the jacks 20Aa-20Af are disposed as positioned at the corners of the hexagonal shape, and slide guides 24Aa-24Ad are disposed between both ends of the upper and lower cutter spokes 4Aa and 4Ad of the tunnel face cutter device 4A and two excess excavating cutter spokes 18Aa and 18Ac. Further, a number of the cutter bits 5A and 19A are mounted to the respective cutter spokes 4Aa-4Al and 18Aa-18Ad. In addition, the parallel link excavator 2A for cutting the tunnel face and the excess excavating cutters 12A are accommodated in the shield cylinder 1A as deviated as a whole from the center of the cylinder 1A to radially outward. As the motive rotor 3A is actuated in the construction of the third embodiment, the parallel link excavator 2A and excess excavating cutters 12A are rotated with their rotary center sequentially deviated within the shield cylinder 1, upon which the parallel link excavator 2A operated to rotate while maintaining the parallel link connection though slightly different in the aspect of the parallel link motion from that in the first and second embodiments, and the tunnel face ground is excavated by means of the many cutter bits 5A mounted to the cutters 4A. When the cutter spokes 18Aa-18Ad of the excess excavating cutters 12A are actuated simultaneously with the excavation of the tunnel face ground with the tunnel-face cutters 4A, the excess excavation is also executed. In an event where the leftward rolling of the shield tunnel boring machine has occurred during the boring operation, the excess excavation is executed with the excess excavation rate of the right side cutter spokes 18Ac made the largest, and with the excess excavation rate of the upper and lower cutter spokes 18Ad and 18Ab as well as the left side cutter spoke 18Aa gradually reduced stepwise, and the leftward rolling can be corrected. When the rolling takes place rightward, on the other hand, the excess excavation rate with the left side cutter spoke 18Aa is made the largest, while the excess excavation rate at the upper and lower cutter spokes 19Ad and 18Ab and the right side cutter spoke 18Ac is reduced gradually stepwise, and the excess excavation is thus performed, so as to be able to correct the rightward rolling. Further, with this position controlling arrangement utilized, the boring of the curved tunnel can be easily executed in the same manner as in the foregoing first and second embodiments. All other constituents and their functions in the present third embodiments are substantially the same as those in the foregoing first and second embodiments. Further, while in the third embodiment the arcuate cutter spokes of the excess excavating cutter 12A is described as divided into four sections, the arrangement is not required to be so limited but may be in three or less sections or five or more sections.

Claims: A shield tunnel boring machine wherein a parallel link excavator (2; 2A) including tunnel-face cutters (4; 4-A) consisting of a plurality of cutter spokes (4a-4g; 4Aa-4Al) to which many cutter bits (5; 5A) are mounted for a planar rotation through parallel movement of a plurality of driven-points, the excavator is additionally provided with at least an excess excavating cutter consisting of a cutter spoke (18; 18A) having many cutter bits (19; 19A) for contributing to normal tunnel excavation of the machine in a desired sectional tunnel shape and to an excess excavation executed for directional control of the tunnel excavation when the spoke (18; 18A) is moved by a jack (20; 20A) with respect to the parallel link excavator (2; 2A), characterized in that the excess excavating cutter comprises a plurality of cutter spokes (18a-18f; 18Aa-18Ad) respectively provided movably at parts of the periphery of the parallel link excavator (2; 2A), a plurality of the jacks (20a-20f; 20Aa-20Af) are coupled respectively to the cutter spokes (18a-18f; 18Aa-18Ad) of the excess excavating cutter and respectively driven independently, and means is coupled to the respective jocks (20a-20f; 20Aa-20Af) for independently selectively adjusting the jacks to project selected ones of the cutter spokes of the excess excavating cutters by a desired amount on a desired side of the axis of the desired sectional tunnel shape for executing an excess excavation for directional control of the tunnel excavation. The shield tunnel boring machine according to claim 1, characterized in that the respective cutter spokes (4a-4g) of the parallel link excavator (2) are provided to form a rectangular shape as a whole and the respective cutter spokes (18a-18f) are disposed symmetrically on both longer sides of the rectangular parallel link excavator (2). The shield tunnel boring machine according to claim 2, characterized in that some (18a, 18c, 18d, 18f) of the cutter spokes (18a-18f) of the excess excavating cutter which are disposed at corner portions of the rectangular shape of the parallel link excavator (2) are formed in an angled shape and are held slidably to corresponding cutter spokes (4a, 4d) of the parallel link excavator (2) at the corner portions. The shield tunnel boring machine according to claim 1, characterized in that the cutter spokes (4Aa-4Af) of the parallel link excavator (2A) are provided to form a hexagonal shape as a whole, and the cutter spokes (18Aa-18Ad) of the excess excavating cutter are provided to form a substantially circular shape along the periphery of the parallel link excavator (2A). The shield tunnel boring machine according to claim 4, characterized in that a pair of peripheral cutter spokes (18Aa, 18Ac or 18Ab, 18Ad) of the excess excavating cutter in the substantially circular shape are arranged in opposing diametrical relationship. The shield tunnel boring machine according to claim 4, characterized in that the cutter spokes of the excess excavating cutter in the substantially circular shape comprise two pairs of radial cutter spokes (18Aa, 18Ac and 18Ab, 18Ad) respectively opposing diametrally horizontal and vertical.

Inventors: INOUE MASAMI, KASHIMA YUTAKA, KONDO NORIO, INOUE, MASAMI, KASHIMA, YUTAKA, KONDO, NORIO
Applicants: DAIHO CORP, DAIHO CORPORATION
Application year: 1995
Main classification: E21D9
IPC codes: E21D9