JPH0762983A - Outbreak device for shield excavator - Google Patents

Abstract

PURPOSE:To reduce the abrasion of a cutter bit and prolong its life. CONSTITUTION:This marginal excavation device is constituted of an outbreak cutter 5 having a shank 7 and a cutter bit 6 fixed with cemented carbide chips 6a and a hydraulic jack 8 reciprocating the cutter 5, the cutter 5 is stored in the cutter head 3 of a shield excavator, and it is protruded from the outer periphery of the cutter head 3 by the hydraulic jack 8 to excavate the natural ground at the time of a marginal excavation. In this marginal excavation device of the shield excavator, the cutter 5 is stored in the cutter head 3 so that it can be freely rotated centering on the axis when it is protruded from the outer periphery of the cutter head 3. Many cemented carbide chips 6a and redially fixed to the cylindrical cutter bit 6, and the cutter bit 6 is naturally rotated at the time of an excavation so that no specific cemented carbide chip 6a is used too hard.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when a shield machine is curved, excavates a ground on the curved side by projecting a digging cutter stored in the cutter head in a radial direction from the cutter head. The present invention relates to an overexcavation device for a shield machine.

[0002]

2. Description of the Related Art A shield machine is a machine for excavating a face by a cutter provided on a cutter head in front of the shield body while applying thrust to the shield body with a shield jack, and excavates an underground pit. In some cases, such as when excavating a curved tunnel, it is necessary to change the excavation direction and make a curving. In such a case, it has been generally practiced in the past to overdug the ground on the curved side by projecting an overcutting cutter called an overcutter stored in the outer peripheral portion of the cutter head in the radial direction from the cutter head. There is. That is, while rotating the cutter head at the front of the shield body, only when the overcutting cutter comes to the curving side, this is projected to excavate the natural ground, and only the portion of the natural rock on the curving side is slightly larger. The overdrilling method of excavating to the diameter is generally used. As a result of this over excavation, the resistance of the ground on the curved side can be reduced, and the shield machine can be curved in the direction of the overburden. As for this overcutting cutter, various structures are shown in, for example, Japanese Utility Model Laid-Open No. 61-121293, and a typical structure thereof is as shown in FIGS. 6 and 7. ing. FIG. 6 is a plan view of a conventional general overburden cutter, and FIG. 7 is a front view of the overburden cutter of FIG. 6. The overburden cutter is a shank a and a cemented carbide tip attached to the upper part of the shank a. It is composed of a cutter bit b to which c is fixed, and its carbide tip c
Are fixed to the tops on both sides of the cutter bit b as shown in the figure. That is, the cemented carbide tip c is provided on both edges of the cutter bit b in the forward and reverse cutting directions indicated by arrows in FIG. 7, in other words, in the rotation direction of the cutter head, and is provided with directionality. It was When excavating while excavating the natural ground with this carbide tip c, if the cutter for excess excavation may rotate even a little about the axis of the shank a, the carbide tip c Since the above-mentioned directionality given to it is lost, it has always been done to prevent the overcutting cutter from rotating. As a known document describing the method for preventing the rotation in the overcutting device of the shield machine, that is, the overcutter device, there is, for example, Japanese Utility Model Laid-Open No. 63-41697.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned conventional overexcavation device for shield machine, the ground is cut only by the two cemented carbide tips provided on both edges of the top of the bit, and these specific tips are cut. Carbide tips are subject to heavy wear and short life. Further, even if an attempt is made to replace the worn carbide tip, it is difficult to replace it from the inside of the shield body, and maintenance requires a lot of time and labor.

In view of the above problems of the prior art, the present invention aims to provide an overdrilling device for a shield machine which can reduce the wear of the cutter bit and prolong its life. To do.

[0005]

The object of the present invention is to provide a "excavation cutter having a shank and a cutter bit attached to the shank, and a driving device for reciprocating the excavation cutter. In the excavator cutter of a shield machine, which stores the overcut cutter in the cutter head of the shield machine and excavates the ground by projecting from the outer periphery of the cutter head by the drive unit during the overcut, Is housed in the cutter head so that it can be freely rotated around its axis when it is projected from the outer periphery of the cutter head, and a large number of chips are radially mounted on the cutter bit to improve wear resistance. This is achieved by a shield excavator overdrilling device as claimed in the claims.

[0006]

The overexcavation device for a shield machine according to the present invention has such a structure. Therefore, when the shield machine is to be bent, the cutter head is rotated and the cutter head is excavated. The excavation cutter stored in the outer peripheral part is made to project only when the cutter comes to the curving side by the drive device, and it is made to enter the natural ground while cutting the natural ground with the chip for natural ground cutting To do. When cutting the ground with this tip, the cutter bit cuts the ground with the tip for rock cutting while pressing its front part against the cutting face, and at the same time it revolves with the rotation of the cutter head. The front part of the bit receives the frictional resistance of the face of the face during its revolution, and the frictional resistance of the face of the face during its revolution causes it to rotate by itself as if it receives a rotational force as if it were rolled on the face of the face, As a result of the rotation of this cutter bit,
Since the ground cutting is not handled in one direction of the cutter bit and is shared over the entire circumference, wear resistance is improved and cutting performance is maintained for a long time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view showing a state when the overexcavation device for a shield machine according to an embodiment of the present invention is inoperative, and FIG.
FIG. 3 is a vertical cross-sectional view showing the operating state of the shield excavator excess machine of the present invention, and FIG. 3 is a partial cutaway view of the shield excavator extra machine of the present invention. FIG. 4 is a rear view showing the internal structure thereof, FIG. 4 is a plan view of an overburden cutter relating to the overburden device of the shield machine of the embodiment of the present invention, and FIG. 5 is a side view of the overburden cutter.

1 to 5, 1 is a shield body of a shield machine, 2 is a center shaft which is rotationally driven by a cutter drive device, 3 is a cutter of a shield machine which has a cutter bit mounted on the front surface and excavates a face. Head, 4
Is a boss at the center of the cutter head provided at the front end of the center shaft. The cutter head 3 has a boss 4 at the center thereof.
It is attached to the center shaft 2 via the shaft and is rotationally driven through the shaft 2 by a cutter driving device (not shown). 3a is a ring-shaped outer peripheral frame forming the outer periphery of the cutter head, and 3b is this outer peripheral frame 3a.
With the Kattas pork that connects the cutter and the center boss 4 of the cutter,
A plurality of bosses 4 are provided radially like a spoke of a bicycle. The skeleton of the cutter head 3 is formed by the outer peripheral frame 3a and the cutas pork 3b.

Reference numeral 5 denotes an overcutting cutter stored in the cutas pork 3b, 6 denotes a cylindrical cutter bit of the overcutting cutter 5, and 6a is for improving abrasion resistance fixed to the cutter bit 6. Is a cylindrical shank slightly larger in diameter than the cutter bit 6 of the overcutting cutter 5. The overcutting cutter 5 has a structure as shown in FIGS. 4 and 5, and a large number of cemented carbide tips 6a are embedded in a cylindrical cutter bit 6 so as to reach the top at radial intervals. The base material of the cutter bit 6 and a large number of these carbide tips 6a cooperate with each other to cut the ground as a whole. The large number of carbide tips 6a radially embedded in the cylindrical cutter bit 6 mainly serve to improve the wear resistance of the entire cutter bit 6, but also contribute to the improvement of the cutting property. In this way, not only the shank 7 but also the cutter bit 6 is formed in a circular cross section, and a large number of cemented carbide tips 6a are radially fixed to the circumference to improve wear resistance. This is a point not found in technology. As will be described later, the extra excavator cutter 5 also adopts a configuration in which it can freely rotate about its axis when it is projected from the outer periphery of the cutter head, as will be described later. Therefore, these configurations are unique to this embodiment.

Reference numeral 8 designates a hydraulic jack for reciprocating the excess excavation cutter 5 so as to project or store it from the cutter head 3, and 8a designates a cylinder of the hydraulic jack 8.
b is the rod end of the piston rod of the hydraulic jack 8, 9
Is a hydraulic hose for driving the hydraulic jack 8 and supplying the hydraulic pressure to the jack 8 and discharging the hydraulic pressure from the jack 8. Although not shown in the figure, the hydraulic jack 8
A piston connected to a piston rod having a rod end 8b is slidably fitted in the cylinder 8a. The bottom of the cylinder 8a is fixed to the fixing member 14 for fixing the hydraulic jack 8 with the pin 13a, and the rod end 8b of the piston rod is fixed to the bottom of the shank 7 with the pin 1a.
It is attached at 3b. Since the piston fitted into the cylinder 8a of the hydraulic jack 8 is slidably fitted, it freely rotates when a rotational force about the shaft center is applied to the cutter bit 6. Since the directionality given to the above-mentioned carbide tip is lost, the conventional device was provided with a detent, but the device of the present embodiment does not have such a detent at all.

Reference numeral 10 has a columnar shank storage space for slidably guiding the shank 7 of the overcutting cutter 5, and 11 is a guide member mounted in the Kattus pork 3b. 10 and overcutting cutter 5
Sealing member for sealing between the cutter bit 6 and
Is a shank sliding bush that is attached to the upper portion of the guide member 10 in the cutas pork 3b, has the same function as the member 10, and has the same cross-sectional shape. The guide member 10 is attached to a position corresponding to the shank 7 when the overexcavation cutter 5 is not projected, and similarly, the shank sliding bush 12 is attached to a position corresponding to the cutter bit 6, and any of these members is attached. Not only guide the shank 7 to slide up and down when the extra excavation cutter 5 projects from the cutter head 3 or is housed in the cutter head 3, but also protrudes the extra excavation cutter 5. At times, it also functions to guide the shank 7 to rotate smoothly. In addition, in the Katta pork 3b,
An opening is formed to facilitate the work of incorporating the overcutting cutter 5 into the cutas pork 3b, and the opening is closed by the lid 15 when the work is completed.

Since the apparatus according to the embodiment of the present invention adopts the above-described structure, when the shield machine is to be bent, the cutter head 3 is rotated and the cutter head is advanced. The excavation cutter 5 stored in the outer peripheral portion of No. 3 is caused to project only when the cutter 5 comes to the curving side by operating the hydraulic jack 8 and the bit base material is allowed to project into the ground while the projection is made. The ground is cut by and the carbide tip 6a. When cutting the ground with the cutter bit 6 in this way, the cutter bit 6 cuts the ground while pressing its front part against the face, and at the same time revolves with the rotation of the cutter head 3. Bit 6
, The front part of the bit receives the frictional resistance of the face when it revolves, and the front face of the bit receives the frictional resistance of the facet,
It receives a rotating force as if it were rolled on the face.
In that case, at the rear part of the cutter bit 6, apart from when the extra excavation cutter is thrusting into the natural ground, as the excavation progresses, almost no friction occurs, so that a frictional force that cancels the rotational force. Does not occur. Then, as described above, the overexcavation cutter 5 in the present embodiment is "a cutter bit 6 is formed in a circular cross section so that a large number of cemented carbide tips 6a are radially fixed to the circumferential portion thereof". , "It is housed in the cutter head so that it can be freely rotated around its axis when it is projected from the outer periphery of the cutter head." ,
Due to the combination of these configurations, the cutter bit 6 is rotated by itself by the above-mentioned rotational force, and as a result of the rotation of the cutter bit 6, the cutting portion of the cutter bit 6 contacting the face is occasionally replaced, which results in a stable ground. Since the cutting is not carried out only by the specific portion of the cutter bit 6 but is shared by the entire circumference thereof, unlike the conventional device, only the specific cemented carbide tip 6a is not overused, and the cutting bit 6 does not have to be overused. The wear resistance can be improved and the cutting performance can be maintained for a long time.

As described above, in the present embodiment, attention is paid to the phenomenon that the cutter bit 6 of the overcutting cutter 5 receives the rotational force due to the frictional force of the face when the cutter head 3 revolves, and it is skillfully utilized. Cutter bit 6
It is possible to obtain the practical effect of reducing wear and prolonging its life, as well as omitting the rotation stop of the overcutting cutter 5 that was indispensable in the conventional technology, which is a field technology. It has an excellent effect. In short, by not providing the rotation stop of the overcutting cutter 5 which is naturally provided in the conventional technique, the effect superior to that of the conventional technique is exerted.

[0014]

As is apparent from the above description, the present invention relates to the construction described in the claims, particularly, "when the overcutting cutter is projected from the outer periphery of the cutter head, its axial center is changed. It is stored in the cutter head so that it can be freely rotated around the center, and a large number of chips are radially fixed to the cutter bit to improve wear resistance. At the time of turning by itself, there is no such thing as a specific rock excavating tip being overused like the conventional technology, the rock is cut using the entire circumference of the cutter bit, As a result, it is possible to provide an overexcavation device for a shield machine that can reduce the wear of the cutter bit and prolong its life. further,
It is not necessary to add a turning stopper for the overexcavation cutter to give directionality to the chips for natural ground excavation, which has been applied to the conventional technology, and a variety of effects can be simultaneously achieved with a simplified configuration. be able to.

The present invention has a basic idea of preventing the cutter bit from rotating,
The idea was to improve by the opposite idea of positively utilizing the rotation of the cutter bit, and the idea is novel.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a non-operation state of an overexcavation device for a shield machine according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state during operation of the overexcavation device for the shield machine according to the embodiment of the present invention.

FIG. 3 is a rear view showing the internal structure of a shield excavator according to an embodiment of the present invention by cutting away a part of the overexcavation device.

FIG. 4 is a plan view of an overburden cutter relating to the overburden device of the shield machine according to the embodiment of the present invention.

FIG. 5 is a side view of an overburden cutter relating to the overburden device of the shield machine according to the embodiment of the present invention.

FIG. 6 is a plan view of a general overburden cutter relating to the overburden device of the conventional shield machine.

FIG. 7 is a front view of the overcutting cutter of FIG. 6.

[Explanation of symbols]

 1 Shield excavator shield body 2 Shield excavator center shaft 3 Shield excavator cutter head 3a Cutter head outer peripheral frame 3b Cutter spoke 4 Shield excavator boss 5 Cutter bit 6 Cutter bit 6a Carbide tip 7 Shank 8 Hydraulic jack 10 Guide member 12 Shank sliding bush

Claims (1)

[Claims] 1. A shank and a cutter for excavation having a cutter bit attached to the shank, and a drive device for reciprocally driving the cutter for excavation. The cutter for excavation is provided in a cutter head of a shield machine. In a digging device for a shield machine that is stored in a digging machine and excavates the ground by driving it from the outer periphery of the cutter head when digging, the axis of the digging cutter when the digging cutter is projected from the outer periphery of the cutter head. An excavator for a shield machine, which is housed in a cutter head so that it can be freely rotated around its center, and a number of chips for improving abrasion resistance are radially fixed to a cutter bit. .