JP6624608B2 - Excavator - Google Patents

Description

  The present invention relates to an excavator, and for example, relates to a technology that is effective when applied to an excavator that excavates the ground to construct a tunnel underground.

  An excavator is a device that constructs a tunnel while pushing a steel cylinder into the ground, and its main ones include a shield machine and a tunnel boring machine (Tunnel Boring Machines: hereinafter, referred to as TBM).

  Shield machines are mainly used for excavating relatively soft geology, such as those used in the formation of subways and sewers in urban areas. On the other hand, TBM is mainly used for excavating relatively hard geology, for example, for use in railways in mountainous areas and formation of a headrace for power generation. TBM has an advantage that the excavation speed is higher than other construction methods, and therefore, it is used for tunnel excavation work requiring an excavation speed.

  In any case, a cutter head is attached to the tip of the excavator in the traveling direction so as to be rotatable along the circumferential direction of the excavator. A plurality of excavating members such as a roller cutter are installed on the front surface of the cutter head. When excavating a tunnel, rock or the like is excavated by rotating the cutter head in a state where the excavating member on the front surface of the cutter head is pressed against a face (excavation surface) (for example, see Patent Documents 1 to 4).

JP 2004-19302 A JP-A-9-273388 JP-A-8-1999982 Japanese Patent No. 3954084

  By the way, in the cutter head of the excavator, the excavation performance with respect to the face at the front center is lower than that at the outer periphery. As a countermeasure, the cutter head has a double structure of the outer digging part and the central digging part (dual cutter head structure), and the central digging part is configured to be able to rotate at high speed independently of the outer digging part. Central excavation performance can be improved.

  However, even with the dual cutter head structure as described above, if the disk-type roller cutter 101 is disposed at the center of the front surface of the cutter head 100 as shown in FIG. 17, the track of the disk-type roller cutter 101 is steep. In many cases, rolling becomes impossible, and in particular, in hard rock (hard rock), the excavation efficiency at the center of the face decreases. As another problem, particularly when excavating a small-diameter tunnel, it is difficult to arrange a plurality of disk-shaped roller cutters 101 of a fixed size in the central excavation portion of the cutter head 100.

  Therefore, as a countermeasure, a cone-shaped roller cutter was installed in front of the central excavation part of the excavator, and the excavation method at the center of the face was made a crushing method. Thereby, the load in the thrust direction applied to the roller cutter of the central excavation part can be reduced, and the center of the face can be efficiently excavated.

  However, when excavating the face of the tunnel, the central excavator of the excavator receives an impact due to the protruding portion (unevenness) of the face, and as a result, there is a problem that the cone-shaped roller cutter of the central excavator is damaged. In particular, in the case of a cone-type roller cutter, since the excavating body is supported by a cantilever, the mechanical strength of the supporting portion is lower than that of a disk-type roller cutter, and a plurality of excavating chips are projected from the excavating body. Since the structure is installed in a state, the excavation tip is easily damaged as compared with the disc type roller cutter. For this reason, as a result of shortening the life of the cutter board of the excavator, correspondence to high-speed excavation and long-distance excavation is hindered.

  The present invention has been made in view of the above technical background, and an object of the present invention is to provide a technique capable of improving the life of a cutter panel constituting an excavator.

In order to solve the above-mentioned problem, an excavator according to the present invention according to claim 1 includes an outer peripheral excavation portion rotatably provided on an outer periphery of a front surface of an equipment body, and the outer peripheral excavation at a front center of the outer periphery excavation portion. A central excavation part provided in a rotatable state independently of the part, the outer peripheral excavation part includes a disk-type roller cutter provided on a front surface of the outer peripheral excavation part, A support member rotatably supporting the central excavation portion, a cone-shaped roller cutter rotatably provided on the front surface of the support member, and a state mechanically connected to the support member. Load adjusting means for adjusting the axial load applied to the cone-shaped roller cutter by allowing the cone-shaped roller cutter to move in the axial direction of the device body. , The outer peripheral excavation part The central excavation portion side is formed on an inclined surface inclined in a direction opposite to the excavation surface, and the disc-type roller cutter provided on the inclined surface has a support shaft such that the cutting edge on the excavation surface side faces inward. It is characterized by being inclined with respect to the excavation surface .

  According to a second aspect of the present invention, in the first aspect of the present invention, the load adjusting means includes a hydraulic cylinder mechanically connected to the rear of the support member, and a mechanically connected hydraulic cylinder. And a connected accumulator.

  According to a third aspect of the present invention, in the first or second aspect of the invention, at least the support member and the cone-type roller cutter of the central excavation portion are provided in a detachable state. And

  According to the first aspect of the present invention, even when the central excavation portion of the excavator receives excessive pressure due to the protruding portion (unevenness) of the face, the cone-shaped roller cutter is moved inward along the axial direction. As a result, excessive pressure applied to the cone-shaped roller cutter can be relieved, so that damage to the cone-shaped roller cutter can be suppressed or prevented. Therefore, it is possible to improve the life of the cutter panel constituting the excavator.

  According to the second aspect of the present invention, it is possible to adjust the load applied to the cone-shaped roller cutter in the central excavation portion of the cutter panel constituting the excavator with a simple structure.

  According to the third aspect of the present invention, it is possible to safely and easily perform inspection and replacement of the cone-shaped roller cutter in the central excavation portion of the cutter panel that constitutes the excavator.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic block diagram of the example which looked at the excavator which concerns on one Embodiment of this invention from the side. It is a front view of an example of the cutter head of the excavator of FIG. It is sectional drawing of the II line of FIG. FIG. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a sectional view taken along line III-III of FIG. 1. FIG. 4 is a sectional view taken along line IV-IV of FIG. 1. FIG. 2 is a perspective view of a cutter head and a front trunk of the excavator of FIG. 1. FIG. 8 is a sectional view taken along line VV of FIG. 7. FIG. 8 is a sectional view taken along line VI-VI in FIG. 7. It is an expanded sectional view of the load adjustment mechanism part of the excavator of FIG. FIG. 11 is an enlarged cross-sectional view when the pressure in the cylinder chamber of the hydraulic cylinder increases in the load adjustment mechanism of FIG. 10. FIG. 11 is an enlarged cross-sectional view when a pressure in a cylinder chamber of a hydraulic cylinder is reduced in the load adjustment mechanism section of FIG. 10. (A), (b) is sectional drawing of the excavator in the tunnel excavation processing process. (A), (b) is sectional drawing of the excavator in the tunnel excavation processing process following FIG. (A), (b) is sectional drawing of the excavator in the tunnel excavation processing process following FIG. It is an expanded sectional view of the load adjustment mechanism part of the excavator concerning other embodiments of the present invention. It is a front view of a cutter head.

  Hereinafter, an exemplary embodiment of the invention will be described in detail with reference to the drawings. In the drawings for describing the embodiments, the same components are denoted by the same reference numerals in principle, and the repeated description thereof will be omitted.

  First, a configuration example of an excavator according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of an example of an excavator according to an embodiment of the present invention viewed from a side, FIG. 2 is a front view of an example of a cutter head of the excavator of FIG. 1, and FIGS. FIG. 2 is a sectional view taken along lines II, II-II, III-III and IV-IV in FIG. 1. In each of the drawings, a center line Cx, Cy in the radial direction of the excavator 1 and a center line Cz in the height direction are shown.

  The excavator 1 of the present embodiment is, for example, a double-barreled shield-type TBM formed in an elongated cylindrical shape, and includes a cutter head (cutter board) 2 and a device main body 3 that supports the cutter head 2. I have.

  The cutter head 2 is an excavator for excavating the ground, and is installed at a tip end of the device main body 3 so as to be rotatable in both left and right directions. As shown in FIG. 2, a plurality of roller cutters (excavation members) 4a and 4b are installed on the front surface of the cutter head 2 in a rotatable state.

  The roller cutters 4a and 4b are members for excavating the face of the tunnel. Here, for example, a cone-shaped roller cutter 4a is installed at the center of the front surface of the cutter head 2, and, for example, a plurality of single-disk-type roller cutters 4b are installed around its outer periphery.

  Further, a through hole 5 is formed in the front surface of the cutter head 2 so as to penetrate between the front and rear surfaces. This through hole 5 is a hole for taking excavated earth and sand excavated by the cutter head 2 into the excavator 1. The structure of the cutter head 2 will be described later in detail.

  The equipment main body 3 includes, for example, three skin plates 7a, 7b, 7c that form the outer shell of the excavator 1. These skin plates 7a, 7b, 7c are formed of, for example, cylindrical steel pipes, and are arranged in series in a state where adjacent ones along the axial direction of the excavator 1 are engaged with each other. I have.

  In the front skin plate 7a, a partition wall 8 that divides a hollow space in the device main body 3 into a face side and an inside of the machine is provided at a position retracted inward from the front end of the skin plate 7a. A hopper 9 is installed below the face side (that is, between the cutter head 2 and the partition 8) in the hollow space of the device main body 3. The hopper 9 is a storage section for temporarily storing excavated earth and sand taken into the excavator 1 through the through hole 5 of the cutter head 2.

  The hopper 9 is mechanically connected to a discharge pipe 10. The discharging pipe 10 extends along the axial direction of the excavator 1 and is mechanically connected to a discharging tank (not shown) outside the mine, and further, a suction apparatus (vacuum method) using air and a vacuum discharging method (vacuum method). (Not shown). The excavated soil stored in the hopper 9 is sucked by the suction device and stored in the earth discharging tank through the earth discharging pipe 10.

  On the other hand, a front fuselage gripper 12, an outer peripheral drive unit 13, a direction correcting jack 14, a propulsion jack 15, a rear fuselage gripper 16, a slip-prevention jack 17 and the like are installed inside the machine in the hollow space of the device body 3.

  The front fuselage gripper 12 is a mechanism for temporarily fixing the front part of the excavator 1 in the tunnel, and as shown in FIG. 3, for example, along the circumferential direction of the skin plate 7a in the skin plate 7a. Are installed at four locations. Each front fuselage gripper 12 is provided with a fixing member 12a which can expand and contract in the radial direction of the skin plate 7a, and fixes the excavator 1 in the tunnel by extending the fixing member 12a and pressing against the anti-wall of the tunnel. Has become possible.

  The outer peripheral drive unit 13 is a rotary drive unit that rotates an outer peripheral excavation unit 2a, which will be described later, of the cutter head 2, and includes a rotary motor 13a, a transmission gear 13b, and a support shaft 13c, as shown in FIG. . The rotary motors 13a are, for example, hydraulic or electric rotary drive sources. As shown in FIG. 3, for example, two rotary motors 13a are installed symmetrically in the skin plate 7a. The transmission gear 13b is a gear that transmits the rotational driving force of the rotary motor 13a to the support shaft 13c. The support shaft 13c is a member that rotatably supports the outer peripheral excavation portion 2a of the cutter head 2 by mechanically connecting the outer peripheral drive portion 13 and the outer peripheral excavation portion 2a of the cutter head 2.

  The direction correcting jack 14 is a mechanism that corrects the direction of excavation of the excavator 1 and is installed in the skin plates 7a and 7b at a position straddling the skin plates 7a and 7b so as to connect the skin plates 7a and 7b. In addition, for example, they are installed in a state of being dispersed at four locations along the circumferential direction of the skin plates 7a and 7b. Pressure oil is supplied from a hydraulic device to the direction correcting jack 14, and the excavator 1 is propelled in a state where the skin plates 7a and 7b are bent in a predetermined direction and angle, thereby excavating the excavator 1 Can be controlled.

  The propulsion jack 15 is a mechanism for propelling the excavator 1, and is installed in the skin plates 7b, 7c at a position straddling the skin plates 7b, 7c so as to connect the skin plates 7b, 7c. As shown in FIG. 4, for example, they are installed at four locations along the circumferential direction of the skin plates 7b and 7c. Each propulsion jack 15 is configured to be extendable and contractable along the axial direction of the excavator 1.

  The rear trunk gripper 16 is a mechanism for obtaining a propulsion reaction force by temporarily fixing a rear portion of the excavator 1 to a tunnel during excavation work. As shown in FIG. Of the skin plate 7c. Each rear trunk gripper 16 is provided with a fixing member 16a that can expand and contract in the radial direction of the skin plate 7c. The excavator 1 is temporarily moved into the tunnel by extending the fixing member 16a and pressing the fixing member 16a against the tunnel wall. It is possible to fix it.

  The slip-off prevention jack 17 is a mechanism for preventing the excavator 1 from slipping down, and is installed at the rear of the excavator 1 so as to be able to expand and contract along the axial direction of the excavator 1. As shown in FIGS. 5 and 6, the slip-down preventing jacks 17 are installed at, for example, two lower positions in the skin plate 7c. Thereby, when it is difficult to secure the reaction force by the rear trunk gripper 16 in the geologically inferior part, it is possible to obtain the reaction force by pressing the slide prevention jack 17 against the segment SG installed behind the excavator 1. It has become. As described above, the manner in which the propulsion reaction force of the excavator 1 is taken can be changed according to the geological condition or the like, so that the tunnel can be formed safely and in a short period of time.

  Next, an example of the structure of the cutter head 2 will be described with reference to FIGS. 1 to 3 and FIGS. 7 is a perspective view of the cutter head and the front body of the excavator of FIG. 1, FIG. 8 is a cross-sectional view taken along line VV of FIG. 7, FIG. 9 is a cross-sectional view taken along line VI-VI of FIG. It is an expanded sectional view of the load adjustment mechanism part of the excavator of FIG.

  The cutter head 2 includes an outer peripheral excavation portion 2a on the outer periphery of the front surface and a central excavation portion 2b at the center of the front surface of the cutter head 2. The outer peripheral excavation portion 2 a is a portion that contributes to excavation of the in-plane outer peripheral portion of the face, and is configured by the outer peripheral portion of the cutter head 2. The outer peripheral excavation portion 2a is rotatable in both left and right directions by the outer peripheral driving portion 13. As shown in FIGS. 2 and 7, a plurality of disk-type roller cutters 4b are rotatably provided on the front surface (the surface facing the face) of the outer peripheral excavation portion 2a with the cutting edge on the outer surface facing the face. It is installed in the state of. The diameter of the disk-type roller cutter 4b is, for example, about 40 cm.

  At the center of the front surface of the cutter head 2, as shown in FIGS. 1, 2, 8 and 9, a through hole 2 c penetrating the front and rear surfaces of the cutter head 2 is formed. , A central excavation part 2b is installed. The central excavation portion 2b is a portion that contributes to excavation of the in-plane central portion of the face, and is installed so as to be rotatable in both left and right directions independently of the outer peripheral excavation portion 2a. As described above, in the excavator 1 of the present embodiment, the central excavation portion 2b is provided so as to be rotatable independently of the outer peripheral excavation portion 2a. Excavation can be improved.

  The central excavation unit 2b includes a support member 20, a cone-shaped roller cutter 4a, a central drive unit 21, and a load adjustment mechanism (load adjustment unit) 22. The support member 20 is a member that supports the central excavation portion 2b in a rotatable state. The support member 20 is formed, for example, in a cylindrical shape, and is rotatably installed in the through hole 2c at the center of the front surface of the cutter head 2 and the cylindrical tube 23 behind the same. Note that the cylindrical tube 23 is installed in the skin plate 7a behind the cutter head 2 with the center axis aligned with the through hole 2c. A ring-shaped seal member 24 is interposed between the inner periphery of the cylindrical tube 23 and the outer periphery of the support member 20.

  For example, two cone-shaped cone-shaped roller cutters 4a, 4a are provided on the front end surface (the surface facing the face) of the support member 20 in the axial direction. And the support shafts of the cone-shaped roller cutters 4a, 4a are inclined with respect to the face so that their outer peripheral surfaces face the face (excavation surface). The cone-shaped roller cutters 4a, 4a are supported in a cantilever manner so as to be rotatable about a support shaft. Each cone-shaped roller cutter 4a is configured by embedding a plurality of excavation chips 4a1 made of cemented carbide or the like in a conical drum. As described above, in the excavator 1 of the present embodiment, the excavation method for the in-plane center of the face is not a separation and crushing method using a disk-type roller cutter, but a crushing method using a cone-type roller cutter. Since the load in the thrust direction applied to the central excavation part 2b can be reduced, it is possible to prevent the excavation from stopping. For this reason, the excavator 1 can improve the excavation property in the center of the face of the excavator 1 and the excavation efficiency can be improved, so that high-speed excavation can be performed and the construction period can be shortened. it can. Although it is difficult to arrange a disk-type roller cutter in the central excavation part 2b (see FIG. 17), the arrangement of the cone-type roller cutter 4a can solve the problem of the arrangement of the excavation member. it can. However, the arrangement number of the cone-shaped roller cutters 4a is not limited to two, but can be variously changed, for example, three.

  On the other hand, a central drive unit 21 is mechanically connected to the rear end surface of the support member 20 in the axial direction. The central drive unit 21 is configured by a rotation motor that rotates the central excavation unit 2b independently of the outer peripheral excavation unit 2a. The central drive unit 21 is, for example, a hydraulic or electric rotary drive source, and is configured to be able to rotate at a higher speed than the rotary motor 13 a of the outer peripheral drive unit 13. At the time of excavation, the rotation speed of the outer peripheral drive unit 13 and the central drive unit 21 is set so that the peripheral speed of the outer periphery of the outer peripheral excavation unit 2a and the peripheral speed of the outer periphery of the central excavation unit 2b match.

  8 and 9, a small diameter portion 20a is formed at the rear end in the axial direction of the support member 20, and a step portion 20b is formed along the outer periphery thereof. As shown in FIGS. 3, 8 and 9, a flat ring-shaped support plate 25 is fitted into the axially rear end of the support member 20 so as to be movable in the axial direction of the support member 20. I have. The inner peripheral portion of the support plate 25 extends to the small-diameter portion 20a of the support member 20 so as to overlap the step portion 20b of the support member 20, but the support member 20 does not hinder the rotation of the support member 20. (The small diameter portion 20a and the step portion 20b) are not joined. A recess extending in the center direction of the support plate 25 is formed at a position symmetrical with respect to the center opening on the outer periphery of the support plate 25. On the other hand, as shown in FIG. 3 and FIG. 9, a pair of frames 26 extending in the axial direction of the excavator 1 are located at symmetrical positions across the support member 20 in the frame body 26 located on the outer periphery of the rear end of the support member 20. Guide plates 27, 27 are erected. The support plate 25 fits the small-diameter portion 20a of the support member 20 into the opening at the center of the support plate 25, and also fits the guide plates 27, 27 into the respective recesses on the outer periphery of the support plate 25, so that the support member 20 can move in the axial direction of the support member 20. It is supported so that it can move along.

  Further, in the vicinity of the outer periphery of the rear end portion in the axial direction of the support member 20, for example, two load adjustment mechanism units 22 are vertically symmetrically installed as shown in FIGS. Each of the load adjusting mechanisms 22, 22 adjusts the axial load applied to the cone-shaped roller cutter 4a by allowing the cone-shaped roller cutter 4a to move in the axial direction of the device body 3. It is. Each load adjusting mechanism 22 includes hydraulic cylinders 22ac, 22ac, and accumulators 22b, 22b, respectively. Thus, the load applied to the cone-shaped roller cutter 4a of the central excavation portion 2b of the cutter head 2 constituting the excavator 1 can be adjusted with a simple structure.

  As shown in FIGS. 8 and 10, the hydraulic cylinder 22a includes a cylinder 22ac, a plunger 22ap, and a hydraulic oil 22af. The cylinders 22ac, 22ac of the hydraulic cylinders 22a, 22a are connected to a common support plate 25. By connecting the two cylinders 22ac, 22ac to the common support plate 25 in this manner, the two cylinders 22ac, 22ac can be smoothly moved along the axial direction of the support member 20.

  The cylinders 22ac, 22ac are detachably connected to the support plate 25. The cone-shaped roller cutter 4a, the support member 20, and the central drive unit 21 are detachably installed, and can be integrally taken out from the inside of the machine or mounted. Thereby, when the cone-shaped roller cutter 4a is inspected or replaced, only the cone-shaped roller cutter 4a, the supporting member 20 and the central drive unit 21 can be taken out from the inside of the machine, so that the cone-shaped roller cutter 4a can be safely and easily obtained. Inspection and replacement of the roller cutter 4a can be performed. Therefore, it is possible to shorten the construction period and flexibly cope with long-distance excavation work.

  Hydraulic oil 22af is filled in the cylinders 22ac of the hydraulic cylinders 22a, and a part of the plungers 22ap is slidably accommodated in the axial direction of the cylinder 22ac. Have been. Here, the portions of the plungers 22ap, 22ap protruding outside the cylinders 22ac, 22ac are fixed to the frame body 26, so that the cylinders 22ac, 22ac are installed so as to be movable in the axial direction. By making the plunger 22ap detachable, the entire central excavation portion 2b (the cone-shaped roller cutter 4a, the support member 20, the central drive unit 21, and the load adjustment mechanism unit 22) may be detachable.

  On the other hand, as shown in FIG. 10, the accumulator 22b is an operating device utilizing the property that gas is compressed by hydraulic pressure. The hollow chamber 22br of the main body 22bb constituting the accumulator 22b is connected to the chamber of the cylinder 22ac through the communication pipe 22c so that the hydraulic oil 22af of the hydraulic cylinder 22a can flow therein. The communication pipe 22c is provided with a supply / discharge oil valve that acts to supply and discharge the hydraulic oil 22af.

  Further, a prada 22bp is accommodated in the hollow chamber 22br of the main body 22bb. The prada 22bp is made of, for example, a flexible member such as rubber, and the inside thereof is filled with a gas such as nitrogen gas through the sealing port 22bf. The prada 22bp is a diaphragm that separates the gas filled therein from the working oil 22af that has flowed into the hollow chamber 22br, and stores the pressurized oil at a compression ratio of the gas in the ladder 22bp. I have. Note that an air supply valve is provided in the sealing port 22bf.

  Here, an operation example of the load adjustment mechanism unit 22 will be described with reference to FIGS. FIG. 11 is an enlarged cross-sectional view when the pressure in the cylinder chamber of the hydraulic cylinder is increased in the load adjustment mechanism section of FIG. 10, and FIG. 12 is a view when the pressure in the cylinder chamber of the hydraulic cylinder is reduced in the load adjustment mechanism section of FIG. It is an expanded sectional view.

  First, FIG. 10 shows the accumulator 22b in an initial setting state. In this state, no force is applied to the cone-shaped roller cutter 4a of the central excavation section 2b in the axial direction toward the inside of the excavator 1. In this case, the ladder 22bp of the accumulator 22b is swelled in the hollow chamber 22br of the main body 22bb. Therefore, the axial movement of the support member 20 is suppressed by the hydraulic pressure in the cylinder 22ac of the hydraulic cylinder 22a. As a result, the cone-shaped roller cutter 4a of the central excavation portion 2b hits the face with a sufficient pressure, so that the face can be well excavated. For this reason, it is possible to improve the excavating ability of the in-plane center of the face of the excavator 1 and improve the excavating efficiency.

  Subsequently, as shown in FIG. 11, when a force is applied to the cone-shaped roller cutter 4 a of the central excavating portion 2 b in the axial direction toward the inside of the excavator 1, the force is applied to the accumulator 22 b by the prada. When the pressure is smaller than the gas filling pressure within 22 bp, the movement of the support member 20 in the axial direction is suppressed by the hydraulic pressure in the cylinder 22ac of the hydraulic cylinder 22a. On the other hand, when an excessive pressure equal to or more than the gas filling pressure in the pladder 22bp of the accumulator 22b is applied to the cone-shaped roller cutter 4a of the central excavating portion 2b in the axial direction toward the inside of the excavator 1, the The gas inside is compressed and the hydraulic oil 22af in the cylinder 22ac flows into the hollow chamber 22br of the accumulator 22b. As a result, the hydraulic pressure in the cylinder 22ac decreases, and the restraining force of the support member 20 due to the hydraulic pressure in the cylinder 22ac is released. As a result, the support member 20 and the cone-shaped roller cutter 4a also move toward the inside of the machine. As described above, in the present embodiment, even when the central excavation portion 2b of the excavator 1 receives an excessive pressure due to the protruding portion (unevenness) of the face, the cone-shaped roller cutter 4a is moved in the machine direction along the axial direction. And the excessive pressure applied to the cone-shaped roller cutter 4a can be reduced, so that breakage of the cone-shaped roller cutter 4a can be suppressed or prevented. Therefore, the life of the cutter head 2 of the excavator 1 can be improved, so that the construction period can be shortened, and the excavator 1 can flexibly cope with long-distance excavation work.

  Subsequently, as shown in FIG. 12, the force applied to the cone-shaped roller cutter 4a of the central excavation part 2b in the axial direction toward the inside of the excavator 1 is weakened, and becomes lower than the sealing pressure in the accumulator 22b in the pladder 22bp. Then, the gas in the ladder 22bp of the accumulator 22b expands, and the hydraulic oil 22af in the hollow chamber 22br flows into the cylinder 22ac chamber. Thereby, the cylinder 22ac moves to the original position by the hydraulic pressure of the hydraulic oil 22af flowing into the cylinder 22ac, and the support plate 25 connected to the cylinder 22ac also moves to the original position. For this reason, the support member 20 engaged with the support plate 25 also moves to the original position. As a result, the cone-shaped roller cutter 4a of the central excavation portion 2b hits the face with a sufficient pressure, so that the face can be well excavated. For this reason, it is possible to improve the excavating ability of the in-plane center of the face of the excavator 1 and improve the excavating efficiency.

  Next, an example of the tunnel excavation method of the present embodiment will be described with reference to FIGS. 13 to 15 are sectional views of the excavator 1 during a tunnel excavation process. The symbol SG in the drawing indicates a segment. 13 and 15, the fixing member 16a of the rear trunk gripper 16 is shown above and below the excavator 1 for explanation.

  Here, for example, an excavation work of a small-diameter upward oblique tunnel such as a water channel for small and medium-sized hydroelectric power generation (a hydraulic pipeline, a headrace channel or a discharge channel), a wide-area gas pipeline, or the like will be described as an example. The rock strength is, for example, 100 MPa or more, the excavation outer diameter is, for example, 1500 to 2500 mm, and the excavation extension is, for example, 1000 m or more.

  First, as shown in FIG. 13A, the fixing member 16a of the rear trunk gripper 16 of the excavator 1 is extended outward from the outer periphery of the excavator 1 and pressed against the tunnel wall, and the excavator 1 The rear slip prevention jack 17 is pressed against the segment SG. Thereby, the excavator 1 is fixed in the tunnel.

  Subsequently, as shown in FIG. 13B, the propulsion jack 15 is extended forward in the axial direction of the excavator 1 and the roller cutter 4 on the front surface of the cutter head 2 is pressed against the ground, and the outer peripheral excavation portion of the cutter head 2 is pressed. The ground of the face of the tunnel is excavated by rotating the central excavation part 2a and the central excavation part 2b. At this time, the peripheral speed of the outer peripheral excavation part 2a and the central velocity of the central excavation part 2b are set to match.

  Next, when the propulsion jack 15 of the excavator 1 is fully extended, the rotation of the outer peripheral excavation portion 2a and the central excavation portion 2b of the cutter head 2 is stopped, and the rear trunk gripper 16 obtains a reaction force, and FIG. As shown in (1), the fixing member 12a of the front fuselage gripper 12 is extended outward from the outer periphery of the excavator 1 and pressed against the tunnel wall to fix the excavator 1.

  Subsequently, the fixing member 16a of the rear trunk gripper 16 is contracted toward the inside of the excavator 1 to release the fixing state by the rear trunk gripper 16, and then, as shown in FIG. To pull the rear skin plate 7c of the excavator 1 toward the front skin plates 7a and 7b, and extend the slip-prevention jack 17 for preventing the excavator 1 from sliding down in the axially rearward direction of the excavator 1. The skin plate 7c is pushed forward.

  Next, as shown in FIG. 15A, while the excavator 1 is fixed by the front trunk gripper 12, the fixing member 16a of the rear trunk gripper 16 is extended toward the anti-wall of the tunnel and pressed against the anti-wall to thereby excavate the excavator. Fix 1

  Subsequently, with the excavator 1 fixed by the front fuselage gripper 12 and the rear fuselage gripper 16, the slip-prevention jack 17 is contracted, and a new segment SG is installed in a free space behind the slip-prevention jack 17.

  Thereafter, as shown in FIG. 15B, the fixing member 12a of the front fuselage gripper 12 is contracted toward the inside of the excavator 1, and the fixing state of the excavator 1 by the front fuselage gripper 12 is released. Thereafter, the entire tunnel is formed by repeating the operations described with reference to FIGS.

  As described above, in the present embodiment, excavation work can be performed safely and at high speed even in an oblique tunnel. In addition, by providing a central excavation portion 2b that can be driven to rotate independently of the outer peripheral excavation portion 2a at the center of the cutter head 2, excavation of the face can be improved. In addition, by installing the cone-shaped roller cutter 4a in front of the central excavating portion 2b of the cutter head 2, it is possible to prevent the excavator 1 from stopping excavation, and thus to improve the excavation efficiency of the face of the excavator 1. be able to. Furthermore, even when the central excavating portion 2b of the excavator 1 receives excessive pressure due to the protruding portion (unevenness) of the face, the cone-shaped roller cutter 4a can be moved inward along the axial direction, and Since excessive pressure applied to the mold roller cutter 4a can be reduced, breakage of the cone-type roller cutter 4a can be suppressed or prevented. As a result, it is possible to shorten the construction period of the excavation work and flexibly cope with long-distance excavation work.

  As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the embodiment disclosed in the present specification is an example in all points, and is limited to the disclosed technology. Not something. That is, the technical scope of the present invention is not to be interpreted in a limited manner based on the description in the above embodiment, but should be interpreted in accordance with the description of the claims. And any modifications that do not depart from the gist of the claims and the technology equivalent to the described technology.

  For example, a configuration is possible in which the central excavation portion 2b of the cutter head 2 of the excavator 1 can be moved back and forth along the axial direction of the excavator 1. In this case, for example, as shown in FIG. 16, in the initial stage of the excavator 1, a space is provided between the end face of the flange head of the plunger 22ap and the inner wall surface of the cylinder 22ac, and the frame body 26 and the A space is left between the front end surface of the cylinder 2ac and the front surface of the cylinder 2ac. Further, a communication pipe 30 for supplying the working oil 22af into the chamber of the cylinder 22ac is provided in the cylinder 22ac, and a control valve is provided in the communication pipe 30. A control valve is provided in the communication pipe 22c on the accumulator 22b side. When it is desired to project the central excavation portion 2b, the communication pipe 22c on the accumulator 22b side is closed by a control valve, and then the hydraulic oil 22af is supplied into the chamber of the cylinder 22ac through the communication pipe 30, as indicated by an arrow PP. Then, since the cylinder 22ac moves leftward in FIG. 16 by the hydraulic pressure, the support plate 25 connected to the cylinder 22ac also moves leftward in FIG. As a result, the rear portion of the central excavated portion 2b is pushed leftward by the support plate 25, and the tip end of the central excavated portion 2b projects toward the face. This makes it possible to carry out excavation in accordance with the ground, for example, by excavating only the central portion of the face in advance by the central excavation part 2b depending on the state of the ground. In a situation where the accumulator 22b is operated, the control valve on the communication pipe 30 side is closed. Further, in FIG. 16, the mechanism of the accumulator 22b and the projecting mechanism of the central excavation part 2b are shared, but the invention is not limited to this. It may be provided separately from the accumulator 22b behind the excavation part 2b.

  The present invention is not limited to the application to the TBM, but can be applied to, for example, an excavator used in a propulsion method or a shield method.

DESCRIPTION OF SYMBOLS 1 Excavator 2 Cutter head 2a Peripheral excavation part 2b Central excavation part 2c Through hole 3 Equipment main body 4a Cone type roller cutter 4a1 Drilling tip 4b Disk type roller cutter 5 Through holes 7a, 7b, 7c Skin plate 8 Partition wall 9 Hopper 10 Discharge pipe 12 Front body gripper 12a Fixed member 13 Cutter drive unit 13a Rotary motor 13b Transmission gear 13c Support shaft 14 Direction correction jack 15 Propulsion jack 16 Rear body gripper 16a Fixed member 17 Slipping prevention jack 20 Support member 20a Small diameter portion 20b Step 21 Central drive unit 22 Load adjustment mechanism unit 22a Hydraulic cylinder 22ac Cylinder 22ap Plunger 22af Hydraulic oil 22b Accumulator 22bb Main unit 22bp Pradder 22bf Enclosure port 22c Communication tube 23 Cylindrical tube 24 Seal member 25 Support plate 26 Frame 27 Id plate 30 communicating tube

Claims (3)

An outer peripheral excavation part rotatably provided on the outer periphery of the front surface of the equipment body,
A central excavation portion provided at a front center of the outer peripheral excavation portion so as to be rotatable independently of the outer peripheral excavation portion,
With
The outer peripheral excavation part,
A disk-type roller cutter provided on the front surface of the outer peripheral excavation portion,
The central excavation part,
A support member for supporting the central excavation portion in a rotatable state,
A cone-shaped roller cutter rotatably provided on the front surface of the support member,
The cone-type roller cutter is provided in a state of being mechanically connected to the support member, and is configured to allow the cone-type roller cutter to move in the axial direction of the device main body, so that an axial direction applied to the cone-type roller cutter is increased. Load adjusting means for adjusting the load;
Equipped with a,
The central excavation portion side of the outer peripheral excavation portion is formed on an inclined surface inclined in a direction opposite to the excavation surface, and the disc type roller cutter provided on the inclined surface has a cutting edge on the excavation surface side facing inward. So that the support shaft is inclined with respect to the excavation surface,
An excavator, characterized in that: The load adjusting means includes:
A hydraulic cylinder mechanically connected behind the support member,
An accumulator mechanically connected to the hydraulic cylinder,
The excavator according to claim 1, further comprising:   The excavator according to claim 1 or 2, wherein at least the support member and the cone-shaped roller cutter of the central excavation portion are provided in a detachable state.

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