JP2928435B2 - Excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator for excavating a ground, and more particularly to an excavator capable of preventing a face from collapsing and easily correcting a direction when excavating a collapsible ground with few fine grains. It is about.

[0002]

2. Description of the Related Art When laying a sewer pipe or a water pipe, an excavator is disposed at the head, and a pipe such as a fume pipe or an iron pipe is continuously provided at the rear end of the excavator and propelled by a main pushing device. The semi-shield method is often adopted. In this method, an excavator is placed on a main pushing device that is installed in line with the design line of the pipeline, and the cutter head of the excavator is driven to excavate the ground and discharge the excavated earth and sand to the outside. While the propulsion is being performed by the main pushing device, the excavator is further propelled by sequentially following a plurality of pipes.

The excavator used in the above construction method has a plurality of spokes each having a bit attached to a conical rotating body which can be eccentrically rotated with respect to the axis of the excavator, in front of the excavator in the traveling direction. The inner wall of the main body corresponding to the location where the cutter is disposed is formed in a conical shape whose diameter increases toward the front.

When excavating the ground with the above excavator,
The face is excavated by a cutter, the excavated earth and gravel are taken in between the rotating body and the inner wall, and the excavated earth and sand is condensed between the rotating body and the inner wall. The face is prevented from collapsing by setting it higher than the water pressure. Excavated earth and sand and gravels crushed between the rotating body and the inner wall are discharged to the ground by fluid transport. Then, the excavator moves forward according to the thrust given by the main pushing device in the excavation process.

[0005]

When the above-mentioned excavator is used, it takes a considerable amount of time to crush the cobblestones and gravel on the ground having a high content of cobblestones and gravel and a small fine grain content.
There is a problem that the surface between the rotating body and the inner wall is in a rough state, stabilizing the face is difficult, and the face may collapse. As a result, the density of the portion corresponding to the upper part of the excavator becomes coarse, so that the excavator rides upward and cannot correct the downward direction, which causes a problem that the propulsion accuracy is deteriorated.

That is, as shown in FIG. 4, when a slack portion is formed above the face, the resistance of the ground acting on the excavator 51 greatly changes above and below the excavator 51, and is applied in the direction of the arrow. The tip of the excavator 51 rises obliquely upward with little resistance in accordance with the thrust being applied. For this reason, even if the forward direction of the excavator 51 is corrected downward, the excavator 51 advances upward with little resistance regardless of this correction. Therefore, it becomes impossible to correct the direction of the excavator, and it becomes impossible to lay a pipeline along the plan line.

An object of the present invention is to provide an excavator capable of preventing a face from collapsing and easily correcting the direction.

[0008]

In order to solve the above-mentioned problems, an excavator according to the present invention has a plurality of spokes in which a shield body is divided into a front chamber and a rear chamber by a partition wall, and a bit is attached to the front chamber. And a conical rotator that can be eccentrically rotated with respect to the axis of the shield body, and the inner wall of the front chamber is formed in a conical shape whose diameter increases toward the front, and the gravel taken into the front chamber is used as the rotator. In an excavator configured to be crushed and ejected to the outside by cooperation with an inner wall, the excavator has an outer peripheral bit selected between the plurality of spokes and has a predetermined inclination with respect to the axis of the rotating body. It is configured by providing a face plate having an angle.

[0009]

According to the above-mentioned excavator, it is possible to prevent the face from collapsing and easily correct the direction even on the ground having a high gravel rate and a low fine grain content.

That is, since a face plate having an outer peripheral bit is selectively mounted at a predetermined angle with respect to the axis of the rotating body between a plurality of spokes, the face plate is secured by a mountain to prevent collapse of the face. You can do it. Further, since the face plate is inclined with respect to the axis of the rotating body, when looseness occurs above the face, the weight of the loosened earth and sand acts on the face plate to prevent the tip of the excavator from rising.

For this reason, when the excavator advances in accordance with the applied thrust, resistance due to earth and sand is generated on the face plate, and the excavator advances straight without traveling upward. Even when the excavator moves upward with little resistance, when the traveling direction of the excavator is corrected, the excavator generates resistance along with the correction and moves forward in the correction direction. Therefore, the direction of the excavator can be easily corrected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the excavator will be described below with reference to the drawings. FIG. 1 is a side sectional view of the excavator, FIG. 2 is a front view of the excavator, and FIG. 3 is a diagram illustrating the direction of a force acting on the excavator when a face is loosened.

In FIGS. 1 and 2, an excavator A includes a shield body (main body) 1 provided at a tip end in a traveling direction, and a first tail shield (first tail) 2 substantially integrated with the main body 1.
And a second tail shield (second tail) 4 fitted to the first tail 2 and connected to the tail 2 via a plurality of direction correcting jacks 3.

The main body 1 and the first tail 2 are connected by bolts 5 and integrated. Further, a partition 2a is provided on the first tail 2, and the front chamber 6 is formed by the partition 2a.
a and a rear chamber 6b. A cutter 7 is arranged in the front chamber 6a, a motor 8 for driving the cutter 7 in the rear chamber 6b, a pipe 9a for supplying mud with controlled specific gravity and pressure, and discharging excavated earth and sand together with the mud. Equipment for controlling the propulsion of the pipe 9b and the excavator A is arranged.

The cutter 7 includes a conical rotating body 10 whose diameter decreases toward the tip of the excavator A, and a rotating body 10.
Are formed by a plurality of spokes 11 provided at the distal end of the vehicle 1 and a face plate 12 selectively provided between the spokes 11. In the present embodiment, four spokes 11 are provided on the rotating body 10, and two spokes 11 are provided between the spokes 11 and at opposing positions.
Two face plates 12 are provided.

An outer peripheral bit 11a is attached to each spoke 11 at the outermost position, and a plurality of bits 11b are attached on the end face of the spoke 11 at different radii. These bits 11a and 11b have a function of excavating the face by the applied thrust and the eccentric rotation of the cutter 7. Also, as shown in FIG. 2, the maximum diameter of the cobble that can be taken into the excavator A is set according to the size between the adjacent spokes 11, that is, the area of the opening between the spokes 11.

The face plate 12 is joined to the side surfaces of a pair of adjacent spokes 11 at a predetermined inclination angle θ with respect to the axis 7a of the cutter 7 by welding or other means over the entire length. Therefore, when earth pressure acts on the face plate 12,
A component force in the radial direction of the excavator A is generated according to the value of the earth pressure and the inclination angle. Therefore, when the same earth pressure acts on the two face plates 12, the component forces in the radial direction cancel each other, and only resistance in the direction of the thrust acts.

A plurality of outer peripheral bits 12a are fixed on the outermost surface of the face plate 12. The bit 12a has a function of breaking the boulder by the applied thrust and the eccentric rotation of the cutter 7 when a boulder having a large diameter is present on the face.

The cutter 7 is rotatably provided on an eccentric shaft 7a having a predetermined amount of eccentricity with respect to the axis 1a of the main body 1. Therefore, the cutter 7 is configured to be rotatable eccentrically about the axis 1a and rotatable about the eccentric shaft 7a. And during normal excavation, the axis 1 of the body 1
a eccentric rotation centered on the eccentric shaft 7a
A forced rotation around is performed.

An inner wall 13 at the tip of the main body 1 and facing the cutter 7 is formed in a conical shape whose diameter increases toward the tip, and the tip of the excavator A is attached to the tip of the excavator A by the inner wall 13 and the rotating body 10. A crushing chamber 14 whose cross-sectional area decreases from the side toward the rear is configured. Accordingly, the gravel taken into the crushing chamber 14 is gradually sent rearward as the excavator A advances, and is crushed by the eccentric rotating body when it is sandwiched between the inner wall 13 and the rotating body 10 in this process. You.

In the excavator A configured as described above, when excavating the easily collapsible ground, the face is supported by the face plate 12 provided between the spokes 11 to prevent collapse. Is possible. Crushing room by face plate 12
The opening area of 14 can be reduced, and the crushing chamber
A large amount of excavated earth and sand is not taken into 14, so that excessive torque does not act on the cutter 7.

As shown in FIG. 3, the excavation of the ground sometimes causes a slack portion C to be formed on the face B above the excavator A in the traveling direction. In this case, the resistance of the earth and sand acting on the portion of the excavator A that is in contact with the loosened portion C on the distal end side is smaller than the resistance acting below the excavator A. Accordingly, when the thrust in the direction of arrow a acts on the excavator A, the excavator A receives an arrow b indicating the difference between the resistance value acting on the upper side and the resistance value acting on the lower side.
Attempts to move in the direction of arrow c, which is the combined direction of the directional force and the thrust. However, the direction of movement of the excavator A (the direction of arrow c)
Is not necessarily in a fixed direction but in a different direction depending on the nature of the looseness and the soil properties.

When the slack portion C is formed on the face B, the slack portion C
And the part opposite to this part (below the face B) has a different resistance. Therefore, the cutter 7 rotates and the one face plate 12A
When the water enters a portion having a large resistance, the earth pressure in the direction of arrow d and the thrust in the direction of arrow a due to the earth and sand act on the face plate 12A, and as a result, a downward radial force is applied to the face plate 12A, that is,
A force acts in the direction of arrow e to hold the excavator A at the tip. At this time, the other face plate facing the face plate 12A
12B is located above the crushing chamber 14, and almost no earth pressure acts on the face plate 12B.

Further, since the cutter 7 performs eccentric rotation about the axis 1a, the face plate 12 performs a vertical movement equal to the eccentric amount every rotation. For this reason, when the face plate 12 invades a portion of the excavator A below which has a high resistance, the earth and sand in the portion tends to move upward, and a downward force f is generated. This downward force f is added to the force e.

Therefore, an upward or downward force corresponding to the difference between the force in the direction of the arrow b and the force in the directions of the arrows e and f acts on the tip of the excavator A. Further, even when the force in the direction of arrow b is large and the tip of the excavator A rises due to the applied thrust, the direction correcting jack 3 is operated to cause the excavator A to move downward due to the resistance between the face plate 12 and the earth and sand. A force can be generated, and the traveling direction of the excavator A can be easily and reliably corrected.

[0026]

As described above in detail, in the excavator according to the present invention, when excavating the ground having a small amount of fine particles which are easily collapsed, the face plate prevents the collapse of the face and takes in a large amount of earth and sand. It is possible to perform stable excavation without any trouble.

Also, even if the face is loosened,
By the earth pressure of the earth and sand acting only on the face plate below, it is possible to apply a downward force to the excavator by this earth pressure, and it is possible to prevent the excavator from lifting and easily correct the direction. It has such features as possible.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an excavator.

FIG. 2 is a front view of the excavator.

FIG. 3 is a diagram illustrating the direction of a force acting on an excavator when a face is loosened.

FIG. 4 is a diagram illustrating a problem.

[Explanation of symbols]

 Reference Signs List A excavator B face C cavity 1 shield body (main body) 2 first tail shield (first tail) 3 direction correction jack 4 second tail shield (second tail) 7 cutter 8 motor 10 rotating body 11 spoke 11a outer peripheral bit 11b Bit 12 Face plate 12a Outer peripheral bit 13 Inner wall 14 Crushing room

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Kozoyama 5-14-10-310 Sagamigaoka, Zama City, Kanagawa Prefecture (56) References JP-A-4-357295 (JP, A) JP-A-4-272392 ( JP, A) JP-A-2-88885 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E21D 9/06 311 E21D 9/06 301 E21D 9/08 E21D 9/12

Claims (1)

(57) [Claims] 1. A conical rotator having a shield body divided into a front chamber and a rear chamber by a partition, having a plurality of spokes each having a bit attached to the front chamber, and being rotatable eccentrically with respect to the axis of the shield body. Excavation that is provided and the inner wall of the anterior chamber is formed in a conical shape whose diameter increases toward the front, and the gravel taken into the anterior chamber can be crushed by the cooperation of the rotating body and the inner wall and discharged to the outside An excavator, wherein the excavator is provided with a face plate having an outer peripheral bit for selecting between the plurality of spokes and having a predetermined inclination angle with respect to the axis of the rotating body.