JP3550443B2 - Mud discharging mechanism in mud pressure shield machine - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a shield machine belonging to the technical field of civil engineering, and more particularly to a mud pressure type shield machine having an improved mechanism for discharging a mud material.
[0002]
[Prior art]
As is well known, many shield methods are provided, and these are widely practiced in the field of civil engineering.
[0003]
This shield method is roughly divided into a manual excavation type and a mechanical excavation type. Machine digging types are further classified into mechanical digging shields (open type), mud pressure shields (closed type), and earth pressure system shields (closed type). By the way, the mud pressure shield method belongs to the earth pressure type shield method.
[0004]
In the case of the above-mentioned mud pressure shield method, a lubricating material called mud material, mud material, mud material, etc. is injected into the front of the cutter of the shield machine, and the mud material and excavated sand are forcibly mixed. The excavated soil is made into a muddy state with plastic fluidity and impermeability. When the inside of the cutter chamber and screw conveyor is filled with mud of such properties and maintained at an operating pressure (mud pressure) that can counteract the groundwater pressure and face pressure, the face is stable without collapse I do. Therefore, the mud pressure shield construction method can be effectively implemented for soils exceeding the applicable range of the shield, such as excess sand content, hard soil, excessive liquidity index, and gravel content.
[0005]
The shield machine used in the mud pressure type shield method has two systems of mud flow paths using the internal shaft and the external shaft (both hollow) of the rotary cutter as a means for injecting and discharging the mud material. I have. One mud flow path extends from the inlet on the rear end side of the internal shaft to the discharge port near the center of the cutter head via the internal shaft, and the other mud flow path on the rear end side of the external shaft. It extends from the injection port to the discharge port near the outer periphery of the cutter head through the space between the inner shaft and the outer shaft. When using these mud channels, the mud material can be discharged from the vicinity of the center or outer periphery of the cutter head to the front of the cutter in synchronization with the ground excavation in order to bring the excavated soil into the aforementioned mud state.
[0006]
In general, in the case of construction that relies on the shield method, it is essential to adapt to various ground conditions in order to proceed the construction safely and promptly. This is the same in the mud pressure shield method. Especially in the case of the mud pressure shield method applied to the ground under bad conditions such as sand and gravel layers, the discharge site of the mud material to the face greatly affects the stability of the face. Therefore, it is desired to inject and discharge a mud material capable of effectively preventing the face from collapsing.
[0007]
[Problems to be solved by the invention]
When the existing mud pressure shield machine is examined from the above viewpoint, the following problems remain. That is, in the case of the conventional machine in which the discharge port of the mud material is provided near the center or the outer circumference of the rotating cutter head, the discharge position of the mud material with respect to the face is set at the discharge port near the outer circumference of the cutter head. Even if a face that is likely to collapse during ground excavation appears because it is confined to the locus circle or the center of the cutter head and these positions cannot be changed, It is difficult to prevent the collapse of the face by supplying the mud material to the surface.
[0008]
As a desirable countermeasure in this case, it is conceivable to specify and / or change the ejection region of the mud material to any of the upper face, the lower face, the right face, and the left face of the face according to the condition of the face. However, since the discharge port provided in the cutter head only rotates on a predetermined trajectory circle when the cutter head rotates, it is not possible to specify or change the discharge region of the mud material.
[0009]
As another countermeasure, it is conceivable to attach a discharge port for the mud material to a non-rotating portion on the tip side of the shield machine. In such a case, it seems that the discharge region of the mud material can be specified, and that the discharge region of the mud material can be changed by changing the mounting position of the discharge port. However, the position of the discharge port cannot be freely selected on the distal end side of the shield machine because various mechanisms are intricate, and there is a great restriction in appropriately setting the position of the discharge port. In addition, since the construction must be interrupted every time the position of the discharge port is changed, the excavation work tends to be stagnant.
[0010]
[Object of the invention]
The present invention has been made to solve various technical problems found in existing mud pressure shield machines. That is, according to the present invention, in the mud pressure type shield machine, identification and change of the mud material discharge area for ensuring the stability of the face can be performed with safe and simple operation, and furthermore, when the mud material discharge area is changed, the construction is stagnant. It is an object of the present invention to provide a mechanism for ejecting a mud material that does not cause a problem.
[0011]
[Means for Solving the Problems]
The mud material discharging mechanism in the mud pressure shield machine of the present invention is characterized by the following means for solving the problem in order to achieve such an object. That is, the thing of the present invention is provided with a shield main body, a cutter for excavating the ground, a supply system for the mud material, and a screw conveyor for discharging mud, and the vertical partition plate has a cylindrical structure. Mud pressure type that assumes that it is installed in the shield body, and that the screw conveyor for discharging mud is placed in the shield body and the mud intake of the screw conveyor is inserted into the cutter chamber In the shield machine, the cutter for excavating the ground has a hollow boss at its axis, and the supply system of the muddy material is located on the outer peripheral surface of the hollow boss and has a plurality of connections distributed in the circumferential direction. An orifice, a plurality of distribution outlets distributed in a circumferential direction in a cutter front area extending from an outer peripheral portion of the hollow boss to an outer peripheral portion of the cutter, a first supply pipe for the mud material, and a communication for the mud material. Tube and That each distribution outlet of the cutter front area and each communication port of the hollow boss are connected to each other via a communication pipe for the mud material, and from the front area of the shield main body. A cutter disposed over the inside thereof is rotatably supported by a bearing in the shield body, and a cutter chamber is interposed between a partition plate in the shield body and a rear surface of the cutter. A hollow external shaft penetrating the partition plate is attached to the rear surface of the hollow boss, these external shafts and the hollow boss communicate with each other, and a supply pipe for the mud material is connected to the external shaft, Also, make sure that the non-rotating inner shaft is inserted from inside the outer shaft to inside the hollow boss. And and A cylindrical distribution valve having a distribution port on the surface and a through hole on the rear surface is attached to the outer peripheral surface of the internal shaft in the hollow boss, and these distribution valves are used for mud material between the inner and outer peripheral surfaces of the internal shaft. Is formed, and the outer peripheral surface of the distribution valve and the inner peripheral surface of the hollow boss are in close contact with each other.
[0012]
the above Of the present invention Each embodiment of the mud material discharge mechanism is as follows. In one embodiment, the hollow boss has a central discharge port on its front surface, the internal shaft is formed of a hollow shaft, and the central discharge port of the hollow boss and the hollow portion of the internal shaft communicate with each other. For mud material Second The supply pipe is connected. In another embodiment, the distribution valve has a distribution port that is long in the circumferential direction, and a circumferential spread angle of the distribution port on the peripheral surface of the distribution valve is 180 degrees or less. In yet another embodiment, a cylindrical bush is mounted on the inner peripheral surface of the hollow boss and interposed between the inner peripheral surface of the hollow boss and the distribution valve. In another embodiment other than these, the stopper is attached to the rear end side of the internal shaft, and the operation lever corresponding to the stopper so as to collide with the stopper is fixed to a non-rotating member close to the rear end side of the internal shaft. .
[0013]
[Action]
In the construction using a mud pressure shield machine, in order to ensure the stability of the face, the muddy material and excavated earth and sand are mixed to create mud with plastic fluidity and impermeability, and this is introduced into the cutter chamber. Then, the inside of the cutter chamber or screw conveyor is filled with such mud. The screw conveyor discharges the mud to the outside of the cutter chamber while maintaining the inside of the cutter chamber at a predetermined working pressure (mud pressure).
[0014]
The muddy material discharge mechanism according to the present invention includes two muddy material supply systems when this embodiment is included. One of them is a flow path extending from the supply pipe to the inside of the internal shaft to the center discharge port (the front surface of the hollow boss). The other one is a supply pipe → between the inner and outer peripheral surfaces of the outer shaft and the inner shaft → inside the hollow boss → a port (the rear surface of the distribution valve) → introduction space (inside the distribution valve) → a distribution port (the periphery of the distribution valve). Surface) → each communication port (peripheral surface of the hollow boss) → each communication pipe → each distribution outlet (the front face of the cutter).
[0015]
In the latter, the latter feeds the mud only from the communication port communicating with the distribution port of the distribution valve. For example, when the distribution port of the distribution valve is set upward, the mud material passes through the latter flow path each time the cutter is rotationally displaced and each connection port of the hollow boss coincides with the upward distribution port. It is discharged only to the upper part of the face. When discharging the muddy material toward the lower part of the face, the right part of the face, the left part of the face, etc., the distribution port of the distribution valve is set or changed to downward, rightward, leftward, etc.
[0016]
The mud material in the above becomes "discharge" when the cutter side is used as a reference, and becomes "injection" when the face side is used as a reference.
[0017]
As described above, when the crushed material is discharged from the front of the cutter toward a predetermined portion of the face (the portion that easily collapses), the easily crushable face portion is primarily supported by the injection pressure of the crushed material. In addition, it is difficult to cause partial collapse of the face and overall collapse of the face linked thereto.
[0018]
【Example】
The mud material discharging mechanism of the mud pressure shield machine according to the present invention will be described based on the illustrated embodiment.
[0019]
The mud pressure type shield machine illustrated in FIGS. 1 to 4 includes a shield main body 11, a ground excavating cutter 31, and a mud material supply system (a central discharge port 32c, a communication port 32d, a distribution discharge port 33b, and a communication pipe described later). 32f, supply pipes 55 and 66) and a screw conveyor 71 for discharging mud.
[0020]
As is apparent from FIG. 1, the two front cylinders 12a and 12b forming a part of the shield body 11 are integrally connected in the front-rear direction with a support plate 12c interposed between these connection portions. Have been. The partition plate 12d has a cylindrical body 12e fixed to the outer peripheral surface. A partitioning plate 12d having a vertical shape in one of the front cylinders 12a is attached to the front surface of a supporting plate 12c via an attachment member 12f. A ring-shaped bearing 12g having an inner diameter larger than the outer diameter of the partition plate 12d is also directly mounted on the front surface of the support plate 12c. The support plate 12c is opened at each part of its plate surface, and the partition plate 12d is also opened at each part of its plate surface. In the other front cylinder 12b, a mounting plate 12h is attached to a corner extending between the upper rear surface of the support plate 12c and the upper inner peripheral surface of the front cylinder 12b. Further, the mounting plate 12i is mounted on the upper inner peripheral surface of the front cylindrical body 12b and behind the mounting plate 12h.
[0021]
A motor 14 for the cutter is mounted in one opening of the support plate 12c. A gear (pinion) 15 attached to the output shaft of the motor 14 projects into the front cylinder 12a. An earth pressure gauge 16 is attached to the partition plate 12d such that one opening is closed from the rear side of the partition plate 12d.
[0022]
As is clear with reference to FIG. 1, the rear cylinder 13 that forms another part of the shield main body 11 follows the front cylinder 11b. A support plate 13a is attached to the front end of the rear tubular body 13, and a cylindrical member 13b protruding forward from inside the front end is also attached. In addition, a mounting plate 13c is attached to a corner between the upper front surface of the support plate 13a and the upper inner peripheral surface of the cylindrical member 13b in the rear cylindrical body 13.
[0023]
The front cylinder 11b and the rear cylinder 13 correspond to the cylinder 13b on the side of the rear cylinder 13 fitted into the front cylinder 11b so as to be able to flex and expand relatively. A bending / stretching jack (center bending jack) 17 for relatively bending and stretching the front cylindrical body 11b and the rear cylindrical body 13 is attached to both mounting plates 12i and 13c.
[0024]
As is apparent from FIG. 1, a shield jack 18, an elector driving device 19, an elector sliding jack 20, an elector elevating jack 21, and the like are provided in the rear cylindrical body 13. Among them, the shield jack 18 is located at a lower portion in the rear cylinder 13 and one end thereof protrudes toward the front cylinder 11b. The erector driving device 19 is located in the upper part in the rear cylinder 13. Further, the erector sliding jack 20 and the erector lifting jack 21 are also installed at predetermined positions on the rear side in the rear cylindrical body 13.
[0025]
As apparent from FIGS. 1 and 2, the cutter 31 for excavating the ground is of an open type. The cutter 31 includes a hollow boss 32, a plurality of spokes 33, a cylindrical frame 34, a cylindrical body 35, a ring plate 36, a ring member 37, a ring-shaped internal gear 38, a ring plate 39, and others. It is a thing.
[0026]
Referring to FIGS. 1 to 4, hollow boss 32 has a hollow structure including a cylinder and a lid closing a front end face and a rear end face thereof. The center of the front surface of the hollow boss 32 is opened for fitting an inner shaft 61 and a cap 63 described later, and two front and rear ring members (for example, made of rubber) 32a and 32b are fitted into the front opening portion. . Of the two ring members 32a and 32b, the front ring member 32a projects from the front surface of the hollow boss 32 to the outside of the hollow boss 32 to form a central discharge port 32c. A plurality of communication ports 32d are formed in the cylindrical peripheral wall of the hollow boss 32 at equal intervals in the circumferential direction. That is, the hollow boss 32 has a plurality of communication ports 32d which are distributed while being kept at equal intervals in the circumferential direction. One end of each communication pipe 32e is connected to each of the communication ports 32d from the outer peripheral surface side of the hollow boss 32. Further, a cutter bit 32f made of a pointed blade is attached to the front surface of the hollow boss 32. The cutter bit 32f has a large number of excavating chips on its front surface. A recess is formed in the center of the rear surface of the cutter bit 32f, and the cutter bit 32f straddles the ring member 32a on the front surface of the hollow boss via the recess.
[0027]
Referring to FIGS. 1 and 2, each of the spokes 33 of the cutter 31 has a large number of cutter bits 33a attached to the front surface thereof. Each of the spokes 33 is formed with a distribution outlet 33b. Therefore, the cutter 31 has a plurality of distribution outlets 33b in the front area thereof and distributed in the circumferential direction. The other end of each communication pipe 32e is connected to each of the distribution outlets 33b. Each connecting pipe 32e has one end connected to each connecting port 32d of the hollow boss 32 and the other end connected to each distribution outlet 33b of the cutter 31 as described above. And the distribution outlets 33b are communicated with each other through the communication pipes 32e.
[0028]
The cylindrical frame 34 is mounted on the rear side of each spoke 33, and the cylindrical body 35 is mounted on the rear side of the cylindrical frame 34. The two ring plates 36 and 39 are arranged inside the cylindrical body 35 while maintaining a front-rear interval, and are mounted inside the cylindrical body 35. Further, the ring member 37 is held by and fixed to both ring plates 36 and 39, and the internal gear 38 is mounted on the rear surface of the ring member 37 and protrudes out of the cylindrical body 35.
[0029]
In addition, a copy cutter 40 is also provided inside the cylindrical frame 34. The copy cutter 40 is provided with a hydraulic operating means 41, and the cutter portion projects from the peripheral surface of the cylindrical frame 34 to the outside of the cylindrical frame 34.
[0030]
The ground digging composed of the hollow boss 32, the spokes 33, the cylindrical frame 34, the cylindrical body 35, the ring plate 36, the ring member 37, the internal gear 38, the ring plate 39, etc. The cutter 31 is arranged on the front surface of the front cylinder 12a as shown in FIG. 1, and the rear side (the cylinder 35 side) is inserted into the front cylinder 12a and assembled to the shield main body 11. In this assembling mode, the cylindrical body 35 and the front cylindrical body 12a are closely fitted inside and outside, and the cylindrical body 12e and the ring member 37 are closely fitted inside and outside. The outer peripheral portion of the internal gear 38 is received in the ring bearing 12g, and the internal gear 38 and the gear 15 on the motor 14 mesh with each other. Thus, the cutter 31 for excavating the ground is rotatably supported by the front cylindrical body 12 a of the shield body 11, and is rotated by receiving the power of the motor 14. A cutter chamber 42 is interposed between the rear surface of the cutter 31 and the partition plate 12d in the front cylindrical body 12a.
[0031]
1 and 3, a hollow outer shaft 51 is attached to the rear surface of the hollow boss 32, and the outer shaft 51 and the hollow boss 32 communicate with each other. The rear side of the external shaft 51 passes through the partition plate 12d. More specifically, the external shaft 51 passes through the boss 52 attached to the central opening of the partition plate 12d. A swivel joint 54 having an inlet 53 is fitted around the outer periphery of the rear end of the outer shaft 51, and a supply pipe 55 for a mud material is connected to the inlet 53. The swivel joint 54 is fixed to an arm 56 extending from the rear surface of the partition plate 12d to support the swivel joint 54 so as not to rotate, and an end of the supply pipe 55 communicates with a mud material supply source (not shown).
[0032]
As is clear from FIGS. 1 and 3, a cap 63 having a plurality of small holes 62 is attached to the tip of an inner shaft 61 composed of a hollow shaft. The inner shaft 61 penetrates through the shaft center of the swivel joint 54, the inside of the outer shaft 51, the inside of the hollow boss 32, and the like, and the cap 63 at the tip thereof is inserted into the ring member 32a of the front wall of the hollow boss. I have. There is a gap between the inner and outer peripheral surfaces of the ring member 32a and the cap 63. Therefore, the inner shaft 61 communicates with the inside of the ring member 32a having the central discharge port 32c. A swivel joint 65 having an inlet 64 is attached to the rear end of the inner shaft 61, and a supply pipe 66 for a mud material is connected to the inlet 64. The end of the supply pipe 66 also communicates with a mud material supply source (not shown).
[0033]
The screw conveyor 71 for discharging mud has a screw 72 for discharging soil built-in, as is obvious. The screw conveyor 71 has a mud intake port 73 at the tip end and operates a shutter 76 for opening and closing the screw motor 75 and the mud discharge port 74 at the rear end side having the mud discharge port 74. A gate jack 77 for the The screw conveyor 71 is arranged from the inside of the rear cylinder 13 of the shield main body 11 to the inside of the front cylinders 12 a and 12 b, and the mud intake 73 is inserted into the cutter chamber 42. The screw conveyor 71 mounted on a predetermined portion in the shield body 11 in this manner is suspended from the mounting plate 77 attached to the upper outer peripheral surface thereof to the mounting plate 12h provided on the upper inner peripheral surface of the front cylindrical body 12b. It is held at an appropriate inclination angle via a supporting jack 78.
[0034]
The above-mentioned mud pressure type shield machine is known or well-known. Accordingly, devices, mechanisms, members, parts, etc., which are necessary and related to the mud pressure type shield machine and whose description and illustration are omitted, may be known or known. In such a shield machine, a metal material having excellent mechanical properties is used as a component requiring particularly high strength. For the other parts, metal, rubber, synthetic resin (including FRP), wood, ceramic, or a composite material of these materials is used at the right place. In addition, as a power machine such as a jack motor, a hydraulic machine is mainly used in order to obtain a stable high output, but an electric motor may be used as the motor. This shield machine is assembled by well-known means such as bolts, nuts, connection fittings, and welding. At this time, seal parts are applied to parts that require airtightness and liquid tightness, and bearings and slide parts are attached as necessary to parts that rotate / linearly move to smooth these movements Can be The foregoing is self-evident in this type of technical field.
[0035]
The muddy material discharge mechanism according to the present invention is configured as follows, with the distribution valve 81 as the main component, in the above-described mud pressure shield machine. That is, as is apparent with reference to FIGS. 1, 3 and 4, a cylindrical distribution valve 81 having a distribution port 82 on the peripheral surface and a communication port 83 on the rear surface is disposed in the hollow boss 32. It is mounted on the outer peripheral surface of the inner shaft 61. More specifically, the rear wall having the opening 83 of the distribution valve 81 and the flange 67 provided on the outer peripheral surface of the inner shaft 61 abut against each other, and are fixed with a stopper (eg, a bolt).
[0036]
The distribution valve 81 attached to the outer peripheral surface of the internal shaft 61 in this manner serves as an introduction space 84 for the muddy material, and the front surface of the introduction space 84 (when the distribution valve 83 is opened). Front surface) hits the inner front surface of the hollow boss 32 and is closed.
[0037]
The distribution port 82 opens the upper peripheral surface of the distribution valve 81 in the illustrated example. The distribution port 82 is long in the circumferential direction, and the circumferential spread angle α is 180 degrees or less, for example, 90 degrees. The distribution port 82 has a plurality of holes circumferentially adjacent to each other on the upper peripheral surface of the distribution valve 81, or has a large number of holes arranged in the peripheral direction on the upper peripheral surface of the distribution valve 81. May be. Like the upper peripheral surface and the lower peripheral surface of the distribution valve 81, the distribution valve 81 may have distribution ports 82 at two places. In such a case, the spread angle α is set to, for example, 90 degrees or less.
[0038]
The opening 83 only needs to open the rear surface of the distribution valve 81. Therefore, it can be said that the shape and size of the communication port 83 may be set arbitrarily, but it is desirable that the rear face of the distribution valve 81 is opened as much as possible.
[0039]
It is desirable that the inner peripheral surface of the hollow boss 32 and the outer peripheral surface of the distribution valve 81 are in close contact with each other in such a manner that a relative slip occurs, so that a cylindrical bush 85 is attached to the inner peripheral surface of the hollow boss 32. And between the inner and outer peripheral surfaces of the hollow boss 32 and the distribution valve 81. A plurality of communication ports 86 are formed on the peripheral surface of the bush 85, and these communication ports 86 coincide with the respective communication ports 32 d of the hollow boss 32.
[0040]
In order to fix or change the direction of the distribution port 82, means including a stopper 91 and an operation lever 93 are combined with the distribution valve 81 integrated with the internal shaft 61. As is clear from FIGS. 1 and 3, the stopper 91 made of a straight bar has a fixed ring 92 at its base end. The operation lever 93 made of a bent bar also has a fixed ring plate 94 at its base end.
[0041]
The manner in which the stopper 91 and the operation lever 93 are attached is clearly shown in FIG. Referring to FIG. 3, in the case of stopper 91, after fixing ring 92 is fitted on the outer periphery of the rear end of inner shaft 61, fixing ring 92 is fixed to the outer peripheral surface of inner shaft 61 (for example, with screws). Thereby, it is attached to the rear end side of the inner shaft 61. In the case of the operation lever 93, the fixing ring plate 94 is fitted on the outer periphery of the rear end of the inner shaft 61 and is brought into contact with the rear surface of the swivel joint 54. Thereafter, the fixing ring plate 94 is fixed to the swivel joint 54 (for example, bolted). By doing so, it is attached to the non-rotating member (the swivel joint 54) close to the rear end side of the internal shaft 61. The stopper 91 and the operating lever 93 attached to a predetermined location in this way project in a predetermined direction and collide with each other. In mounting these components, first, the operation lever 93 is mounted, and then the stopper 91 is mounted.
[0042]
The stopper 91 having the fixed ring 92 and the operation lever 93 having the fixed ring plate 94 are made of a material that does not undergo low elastic deformation or plastic deformation. A typical example thereof is a metal-made one.
[0043]
When excavating underground (ground) using the mud pressure shield machine shown in the embodiment of the present invention, the motor 14 is driven by a power transmission path such as the motor 14 → gear 15 → internal gear 38 → cutter 31. The power is transmitted to the cutter 31. The cutter 31 which rotates by receiving the power of the motor 14 excavates the ground through the cutter bits 32 f and 33 a on the front surface thereof, and removes the earth and sand generated by the excavation into the cutter chamber 42 from between the open portions of the cutter 31. take in.
[0044]
In synchronization with the excavation of the ground, the supply system (two systems) of the mud material injects a well-known mud material toward the face as follows. That is, one supply system discharges the mud material near the center of the face through a flow path such as a not-shown mud material supply source → supply pipe 66 → the inside of the inner shaft 61 → the center discharge port 32c, and the other. One supply system is a mud material supply source (not shown) → supply pipe 55 → between the inner and outer peripheral surfaces of the outer shaft 51 and the inner shaft 61 → inside the hollow boss 32 → through port 83 → introduction space 84 (inside the distribution valve 81) → The mud material is discharged to a predetermined portion of the face through a flow path such as the distribution port 82 → the communication port 86 of the bush 85 → the communication port 32d of the hollow boss 32 → the communication pipe 32e → the distribution discharge port 33b.
[0045]
When the mud material is supplied in such a manner at the time of ground excavation, the cutter 31 takes in these into the cutter chamber 42 while kneading the mud material and the excavated earth and sand with the cutter bits 32f and 33a on the front surface thereof, Even in the process where the mud material and the excavated earth and sand flow into the cutter chamber 42, they are kneaded by the spokes (cutter frames) 33. Therefore, the kneaded material of the mud material and the excavated earth and sand introduced into the cutter chamber 42 exhibits a homogeneous mud state having plastic fluidity and water impermeability. When the insides of the cutter chamber 42 and the screw conveyor 71 are filled with such mud, the mud pressure acts on the face to ensure the stability of the face.
[0046]
The earth pressure gauge 16 constantly measures the mud pressure in the cutter chamber 42. Further, a control means (control panel including a computer not shown) which operates in response to the measurement signal controls the screw conveyor 71 so as to maintain the conveyor unloading amount per unit time at a predetermined value. Accordingly, the screw conveyor 71 driven by the power of the motor 75 discharges the mud to the outside of the cutter chamber 42 in accordance with the shield propulsion amount, and also appropriately holds the mud pressure in the cutter chamber 42.
[0047]
When the mud pressure shield machine is in the above-described operation state, the internal shaft 61 and the distribution valve 81 do not rotate, but the hollow boss 32 of the cutter 31 rotates as obvious. In such a relationship between rotation and non-rotation, each of the communication ports 32d of the hollow boss 32 orbiting on the outer peripheral surface of the distribution valve 81 coincides with the distribution port 82 of the distribution valve 81, and these communication ports 32d are introduced. The space 84 (inside the distribution valve 81) communicates. Moreover, each communication port 32d is connected to each distribution discharge port 33b of the cutter 31 via a communication pipe 32e. Therefore, only when each communication port 32d coincides with the distribution port 82, the mud material is supplied to each distribution discharge port 33b, and each distribution discharge port 33b when each communication port 32d and the distribution port 82 are in a mismatch state. Is not supplied with mud. Therefore, the region where the mud material is injected into the face through each distribution outlet 33b is limited. By the way, when the distribution port 82 of the distribution valve 81 is set to the upward state as shown in FIGS. 3 and 4, each of the communication ports 32d of the hollow boss 32 reaches the α region in FIG. Since the mud material is discharged from each distribution discharge port 33b only during the interval, the mud material is mainly injected toward the upper face of the face. When the mud material is injected into the upper side of the face in this way, the distance from the injection point to the mud intake 73 of the screw conveyor 71 becomes longer in terms of distance and time, so that excavated earth and sand are removed. The mud material is sufficiently stirred and kneaded.
[0048]
When changing the discharge direction (injection area) of the mud material to the face, for example, when mainly injecting the mud material toward the lower part of the face, the operation lever 93 facing upward in FIG. It is detached from the joint 54 and attached downward. In this case, the internal shaft 61 is temporarily rotated (rotational displacement of 180 degrees) until the stopper 91 collides with the downward operation lever 93. Therefore, the distribution valve 81 attached to the inner shaft 61 also rotates by 180 degrees, so that the distribution port 82 faces downward. When the distribution port 82 of the distribution valve 81 faces downward, the contaminated material is mainly injected toward the upper part of the face, contrary to the above. When injecting the mud material into the left face and right face of the face, the distribution port 82 may be changed to the left or right by the operation similar to the above. The orientation of the distribution port 82 can also be changed by changing the attachment angle of the stopper 91 with respect to the internal shaft 61 instead of the operation lever 93.
[0049]
As described above, when injecting the muddy material to the face side with the specific portion of the face (the portion that easily collapses) as a target, the face portion is mainly supported by the injection pressure of the muddy material. It is unlikely that a serious face collapse or an overall face collapse linked to this will occur.
[0050]
The mud material discharging mechanism according to the present invention can be applied to various types of mud pressure shield machines equipped with an open type cutter 31. The open-type cutter 31 includes a cutter having a kneading blade on the rear surface of the cutter. The distribution valve 81 may have its front surface closed. When the inner peripheral surface of the hollow boss 32 and the outer peripheral surface of the distribution valve 81 are directly in close contact, the bush 85 may be omitted. The direction of the distribution port 82 of the distribution valve 81 is determined by the stopper 91 and the operation lever 93, and the fixing of the stopper 91 to the internal shaft 61 and the fixing of the operation lever 93 to the swivel joint 54 use a lock pin and a lock hole. Simple operation means such as fitting, fitting using unevenness, and tightening with a double nut may be employed. When the direction of the distribution port 82 is fixed to any of upward, downward, rightward, and leftward, the stopper 91 and the operation lever 93 are omitted, and the internal shaft 61 is simply fixed (non-rotationally held). Good.
[0051]
In other embodiments, a solid (non-hollow) inner shaft 61 may also be employed. In this case, there is only one supply system for the mud material. Therefore, the supply pipe 66 for the mud material, the swivel joint 65, and the like are omitted, and the holes and the ports on the front side of the cutter, which communicate with the internal shaft 61 in the above, are also omitted (closed).
[0052]
【The invention's effect】
The mud material discharge mechanism according to the present invention has the following effects in a mud pressure shield machine.
[0053]
One of them is that the mud material can be mainly injected into a predetermined portion of the face (a portion that easily collapses) depending on the distribution valve. In the case where such measures can be taken, the face portion that easily collapses is supported and stabilized by the injection pressure of the mud material. Therefore, partial collapse of the face and overall collapse of the face linked thereto are unlikely to occur. In particular, when pouring the muddy material into the upper part of the face, the distance from the injection point to the muddy soil intake of the screw conveyor becomes longer in terms of distance and time, so that the excavated sediment and muddy material are sufficient. Since it is homogeneously stirred and kneaded, the mud effect is further enhanced.
[0054]
Another is that the direction of the distribution valve (distribution port) changes only by rotating and displacing the internal shaft. Therefore, the change of the mud material discharge area (injection area) according to the face condition can be performed by a simple operation. In addition, there is no need to interrupt the construction for such an operation, so that the construction does not stagnate.
[0055]
Still another one is that the operation of the distribution valve for changing the direction of the distribution port, that is, the operation of the distribution valve in the hollow boss, can be performed on the rear end side of the internal shaft (away from the cutter). That is. If such remote control can be performed, there is no danger of touching a dangerous cutter, and therefore, no injury is caused.
[0056]
Still another is that it is sufficient to simply add a simple distribution valve to a ready-made shield machine as a main component. Therefore, measures for maintaining the stability of the face at a higher level can be taken at low cost.
[Brief description of the drawings]
FIG. 1 is a vertical sectional side view showing an embodiment of a mud material discharging mechanism according to the present invention.
FIG. 2 is a front view showing one embodiment of a mud material discharging mechanism according to the present invention.
FIG. 3 is a longitudinal sectional side view showing an enlarged main part of the mud material discharging mechanism according to the present invention.
FIG. 4 is an enlarged vertical sectional front view of a main part of the mud material discharging mechanism according to the present invention.
[Explanation of symbols]
11 Shield body
12a Front cylinder
12b front cylinder
12d partition plate
12g bearing
13 Rear cylinder
31 Cutter for ground excavation
32 hollow boss
32c Central outlet
32d contact
32e connecting pipe
33 Cutter spokes
33b Distribution outlet
42 cutter chamber
51 External axis
54 Swivel joint (non-rotating member)
55 Supply pipe for mud material
61 inner shaft
66 Supply pipe for mud material
71 Screw conveyor for mud discharge
74 Inlet entrance for screw conveyor
81 Distributing valve
82 distribution port
83 entrance
84 Introducing space for mud material
85 Bush
91 Stopper
93 Control lever

Claims (5)

A shield body, a cutter for excavating the ground, a supply system for mud material, and a screw conveyor for discharging mud, and a vertical partition plate is mounted in the shield body having a tubular structure. In the mud pressure type shield machine that assumes that the screw conveyor for mud discharge is placed in the shield body and the mud intake of the screw conveyor is inserted in the cutter chamber, The cutter has a hollow boss at the axis thereof, and a supply system for the mud material is provided on the outer peripheral surface of the hollow boss and a plurality of communication ports distributed in a circumferential direction, and an outer peripheral portion of the hollow boss. A plurality of distribution outlets distributed in a circumferential direction in a cutter front area extending from the outer peripheral portion of the cutter to a first supply pipe for a mud material, and a communication pipe for a mud material, and, The distribution outlets and the communication ports of the hollow bosses are connected to each other via a connecting pipe for the mud material, and are arranged from the front area of the shield body to the inside thereof. The cutter is rotatably supported by a bearing in the shield body, a cutter chamber is interposed between the partition plate in the shield body and the rear surface of the cutter, and a hollow penetrating the partition plate in the shield body. The external shaft of the hollow boss is attached to the rear surface of the hollow boss, the external shaft and the hollow boss communicate with each other, and the supply pipe for the mud material is connected to the external shaft, and the non-rotating type and this internal shaft is inserted over the interior of the hollow boss from inside the outer shaft, and has a dispensing port on the circumferential surface, a cylindrical dispensing valve having a through opening in the rear surface of the inner shaft within the hollow boss On the outer surface The distributing valve, the introduction space for the mud material is formed between the inner and outer peripheral surfaces of the inner shaft, and the outer peripheral surface of the distributing valve and the inner peripheral surface of the hollow boss are in close contact with each other. And a mud discharge mechanism. The hollow boss has a central discharge port on the front surface thereof, the internal shaft is formed of a hollow shaft, the central discharge port of the hollow boss communicates with the inside of the internal shaft, and the internal shaft has a second The mud material discharge mechanism according to claim 1 , wherein the supply pipe is connected to the feed pipe. 2. The mud material discharging mechanism according to claim 1, wherein the distribution valve has a distribution port that is long in the circumferential direction, and a circumferential spread angle of the distribution port on the peripheral surface of the distribution valve is 180 degrees or less. 2. The mud material discharging mechanism according to claim 1, wherein a cylindrical bush is attached to an inner peripheral surface of the hollow boss and is interposed between the inner peripheral surface of the hollow boss and the distribution valve. The mud material according to claim 1, wherein the stopper is attached to a rear end side of the inner shaft, and an operation lever corresponding to the stopper so as to collide with the stopper is fixed to a non-rotating member adjacent to the rear end side of the inner shaft. Discharge mechanism.

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