JPH04160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a large-diameter shield machine used when constructing a horizontal shaft such as a tunnel underground. (Prior art and its problems) In a cutter rotating mechanical shield machine,
The outermost bits are the most susceptible to wear, especially when digging through gravel or over long distances. Therefore, in order to arrange a large number of bits on the outer periphery, a ring was attached to the outermost periphery of the spoke-shaped cutter, and the bits could be placed on that ring, thereby reducing the burden on each bit. Shield machines are already available. However, when the conditions for the bit are particularly severe, such as when the ground is very hard or contains a large amount of large-diameter gravel, the bit must be replaced while digging. In this case, as shown in Fig. 5, after improving the ground by injecting chemicals in area A of the front face G to prevent groundwater from flowing in and collapsing the ground, people can He went out to the face side and replaced bit 7'. However, this method requires a large amount of money to improve the ground and is also dangerous during the work. In addition, since it is difficult to improve the ground from the sea, especially when drilling under the seabed, it is necessary to resort to injecting chemicals from inside the machine, which is costly and has the drawback of poor workability. (Object of the Invention) The present invention has been proposed in view of the above points, and its purpose is to enable the bits on the outer periphery of cutter spokes to be easily replaced from within the machine, thereby eliminating the need for ground improvement work and reducing the cost. An object of the present invention is to provide a shield machine that saves energy and improves safety during work. (Means for Solving the Problems) That is, in order to achieve the above object, the present invention provides a large-diameter shield machine that is rotatable and has a hollow shape inside which can communicate with the inside of the mine. A center shaft in which a working space is formed, a cutter spoke connected to the center shaft and also having a hollow shape, and an outer peripheral ring provided on the outer periphery of the cutter spoke and having the same hollow shape. , the bit provided in the outer circumferential ring is replaceable from the working space side within the outer circumferential ring. (Function) In the present invention, the center shaft of the cutter is made hollow with a large diameter so that the inside becomes a working chamber, and the cutter spokes and outer ring are made with a large diameter hollow structure that allows a person to pass through the center shaft. This allows the bits on the outer ring to be replaced from inside the machine. (Embodiments) Preferred embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B show a front view and a partial side sectional view showing the internal structure of a first embodiment of the present invention. 1 in the figure is a large-diameter shield cylinder, and a face-side chamber 3 is defined through a partition wall 2 formed in the front part of the shield cylinder. A cutter 4 with a rotatable diameter is provided. This cutter 4 is a large hollow cutter that extends radially toward the outer periphery of the shield tube 1, has a bit 7 on the front side, and has a working space inside which a worker can enter and exit. A ring-shaped large cross-section outer circumference ring 6 which connects the spoke 5 and the outer circumference of the cutter spoke 5 and has a bit 7 on the front side and a working space formed inside, and the cutter spoke The base end of the shaft 5 is connected to the front end, and the center shaft 9 has a substantially bottomed cylindrical shape and a large diameter and is rotatable by the drive of a drive motor 8. The inside of this large-diameter center shaft 9 is hollow, and there is a partition wall 2 in the center of the partition wall 2.
The interior of the chamber is constructed so as to function as a working chamber. Furthermore, an opening 9a is provided at an appropriate location on the large-diameter center shaft 9 through which a person can enter and exit the interior.
It goes without saying that a reinforcing material (not shown) may be provided inside the hollow center shaft 9 as necessary to increase its rigidity. Reference numeral 10 denotes a central cutter that is driven independently of the large cutter 4 described above, and is used to excavate the front surface of the large diameter center shaft 9 that is not excavated by the cutter 4 . The center cutter 10 has a proximal end fixed to a boss 12 at the tip of a center shaft 11 that is provided through the approximate center of the large-diameter center shaft 9, and has a plurality of holes extending radially toward the outer periphery of the shield tube 1. A cutter spoke 13, a large number of bits 14 provided on the front side of the cutter spoke 13, and a center shaft 11.
It consists of a fishtail-shaped bit 15 etc. provided at the tip. Further, the rear part of the center shaft 11 is connected to a cutter drive motor 17 via a rotation transmission mechanism 16, and by driving the cutter drive motor 17, the center cutter 10 is rotated to excavate the ground. ing. Note that the rear end of the center shaft 11 is supported via a bearing 18 and a support member 19. Thus, the earth and sand excavated by the central cutter 10 stays in the chamber 3 together with the earth and sand excavated by the large cutter 4 , and is discharged by the discharge mechanism 20 . That is, this discharge mechanism 20 has a well-known screw conveyor configuration in which a screw 22 is built in a casing 21 whose tip penetrates the partition wall 2 and communicates with the chamber 3, and discharges the earth and sand in the chamber 3 to the outside. It is for. Note that the drive motors 8 and 17 are provided on support members 23 and 19, respectively. In addition, the large diameter center shaft 9 is mounted on a bearing 24.
A support member 25 provided inside the shield tube 1 via
It is supported by et al. Furthermore, a manhole 27 for people to enter and exit the chamber 3 from the mine side 26 is provided in the partition wall 2 and the partition/support member 2A provided behind it. In addition, 2
8 is a seal, 29 is behind spoke 5, and
Reference numeral 30 denotes mixing blades provided at the rear of the spokes 13, respectively. Thus, during excavation work, excavation of the ground is performed by the large cutter 4 and the central cutter 10 , and excavated earth and sand are taken into the chamber 3. In addition, depending on the nature of the ground during this process, although not particularly shown in the diagram, a mud material injection mechanism for injecting mud material, such as bentonite solution, into the ground or chamber 3 may be installed on the shield machine. In some cases, the excavated earth and sand are mixed with mixing blades 29, 30, etc., and converted into so-called mud.
This excavated earth and sand is then discharged to the outside via the earth removal mechanism 20 . However, in this excavation work, the outer ring 6
If the bit 7 provided in the center shaft 9 is worn out or damaged, the present invention has a structure in which the center shaft 9 is hollow and the inside serves as a working chamber.
The cutter spokes 5 and the outer circumferential ring 6 also have a hollow structure with a large diameter so that a person can pass through them. For this reason, for example, in order to replace the bit 7 attached to the outer ring 6, a person enters the work chamber inside the center shaft 9 through the center shaft opening 9a leading to the mine side 26, and from there inserts the large diameter cutter spoke. 5. Pass through the large diameter outer ring 6 to reach the position of the bit 7 to be replaced. Then, as shown in FIG. 2A, remove the bit fixing plate 7a provided in the outer circumferential ring 6, and after cutting the welded part a of the bit 7, as shown in FIG. 2B, Attach the insertion guide 7b and apply the new replacement bit 7A to the rear of the existing bit 7. Next, the replacement bit 7A is pushed forward by a hydraulic jack 31 placed behind the replacement bit 7', and the existing bit 7 is pushed out of the cutter spoke 5. The extruded bits 7 can also be recovered from the screw conveyor. After pushing the replacement bit 7A to a predetermined position, the bit 7A is fixed to the outer ring 6 by welding from inside the outer ring 6. After that, the hydraulic jack 31 and the bit insertion guide 7b are removed, and the bit fixing plate 7a is again attached to the rear of the new bit 7A as shown in FIG. At this time, bit 7
A is fixed to the bit fixing plate 7a by bolts, welding, or the like. With this method, the bit 7 of the outer ring 6 can be easily replaced with a new bit 7A from inside the shield machine, eliminating the need for conventional ground improvement, reducing costs, and allowing people to replace the shield machine. There is no need to go outside, so the risk is lower. Furthermore, the time required for replacement can be shortened. Note that the bits provided on the outer ring 6 can be replaced not only with the bits 7 that protrude toward the face side, but also with the bits 7 that protrude from the outer end of the outer ring 6 in the radial direction of the cutter 4 , as shown in FIG. The bit 70 fixed by the bit fixing plate 70a can also be replaced in the same way. In addition, although the above describes an example of a so-called large-diameter mud pressurized shield machine,
As shown in FIG. 4, even in shields with cutter face plates such as mud water pressure shields, earth pressure balance shields, and mud shields, there is a passage 3 behind the face plate 31.
2, the outermost bit 33 can be replaced from within the machine. (Effects of the Invention) As described above, according to the present invention, the bits of the outer ring can be easily replaced from inside the shield machine without going outside the machine. This is no longer necessary, and costs can be reduced accordingly. (b) Since the worker does not need to go outside the shield machine, the danger of work is reduced and safety is improved. (c) Bits can be easily replaced from inside the shield machine, reducing the time required for replacement. There are other effects.

[Brief explanation of drawings]

FIG. 1A is a front view of an embodiment of the shield machine according to the present invention, B is a partial side sectional view showing the internal structure of the same, FIGS. FIG. 3 shows another example of the outer ring bit of the present invention, and FIG. 4 shows another example of the outer ring bit of the present invention.
FIG. 5 shows a conventional example. 5... cutter spoke, 6... outer ring,
7,7A...bit, 9...center shaft.

Claims (1)

[Claims] 1. A large-diameter shield machine has a center shaft that is rotatable and has a hollow working space that can communicate with the inside of the mine, and a center shaft that is connected to the center shaft and that is also hollow. The cutter spoke is provided with a shaped cutter spoke and a hollow outer ring provided on the outer periphery of the cutter spoke, and the bit provided in the outer ring is replaceable from the working space side in the outer ring. A shield machine characterized by the following.