KR0175171B1 - Cutter head of tunnel boring machine - Google Patents

Abstract

It aims at reducing the unloading load added to the disk cutter, improving the life of the bearing supporting the disk cutter, and preventing uneven wear of the disk cutter.

In a tunnel excavator which supports a plurality of disk cutters 2 on the front of the cutter head 1 rotatably provided on the front face of the excavator main body, when the cutter head 1 is rotated. Set the rotation axis vector (grab in the right direction screw direction) when the cutter 2 is in contact with the ground to be excavated and rotated (B), and the central axis vector (grab in the direction from the excavator toward the cutting blade side) of the cutter head. (C) and the disk cutter (2) from the rotation center axis (1a) of the cutter head (1) orthogonal to both the rotation axis vector (B) of the disk cutter (2) and the center axis vector (C) of the cutter head. When the vector heading toward the rotation axis 2a of (e) is (E), the internal product F = E × B of (E) and (B) and the internal product F * C = (E x) of the central axis vector (C) of the cutter head. The rotating shaft 2a of the disc cutter 2 is arrange | positioned so that B) * C may become positive (+) value, and the lateral load applied to the inside of the disc cutter 2 is Since small and, it is also, at the same time forming a lateral load is balanced in the inside and the outside, which is also smaller distributed load itself, by a lateral bearing is broken at an early stage, or it is possible to prevent the disc cutter uneven wear.

Description

Cutter head device of tunnel excavator

1 is a front view of a conventional tunnel excavator.

2 is an explanatory diagram for explaining the operation of the conventional disc cutter.

3 is a front view of a tunnel excavator which is an embodiment of the present invention.

4 is an explanatory diagram of a vector definition of a disc cutter device which is one embodiment of the present invention, and seen from the front side (cutting blade side) of the tunnel excavator.

5 is an explanatory diagram of a vector definition of a disc cutter device according to an embodiment of the present invention, and is a cross-sectional view along the line G-G in FIG.

6 is an explanatory view of the operation of the disc cutter device according to one embodiment of the present invention.

7 is a diagram comparing lateral loads acting on each part of a disc cutter and a conventional disc cutter, which is an embodiment of the present invention.

8 is a diagram showing an average of lateral loads of a disc cutter, which is an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: Cutter head 1a: Center of rotation axis

2: disc cutter 2a: center of rotation axis

α: offset amount B: rotation axis vector of the disc cutter

C: Center axis vector of cutter head D: Outer diameter of disc cutter

E: Vector from the center of rotation of the cutter head toward the axis of rotation of the disc cutter

F: Cross product of E and B

The present invention relates to a cutter head of a tunnel excavator for excavating a tunnel.

As a conventional tunnel excavator, for example, Japanese Patent Application Laid-Open No. 62-133792 or Japanese Patent Laid-Open No. 62-273394, Japanese Patent Application No. 63-171496, Japanese Patent Application Laid-Open No. 1-164394, Japanese Patent Application Laid-Open No. 2-217593 As described in Japanese Patent Application Laid-Open No. 3-115699, Japanese Patent Laid-Open No. 3-1806690, Japanese Patent Laid-Open No. 4-47096, and Japanese Patent Laid-Open No. 4-64691, the entire rotation of the excavator body is performed. It is known that a plurality of disc cutters are rotatably supported on the front surface of a cutter head which is freely provided.

For example, Japanese Patent Application Laid-Open No. 62-133792 discloses that a plurality of disc cutters rotate on a front surface of a cutter device detachable from a cutter drive shaft so that the center of rotation intersects the center of the cutter drive shaft described above. It is attached to the structure.

In addition, in Japanese Patent Application Laid-Open No. 63-171496, a rotary detector is provided so as to face a tip of a roller cutter supported on a cutter wheel, and the indicator light is turned on by a signal detected by the rotary detector. The center of rotation of each roller cutter is arranged to intersect the center of rotation of the cutter wheel.

In Japanese Patent Application Laid-Open No. 1-164394, the shaft supporting the cutter at one end in the axial direction of the cutter is attached to the chamber so as to be inclined so as to extend from the opening side to the outside, and the cutter of this publication also has a center of rotation. It is arranged to intersect the center of rotation of the cutter disc.

In Unexamined-Japanese-Patent No. 2-93390, it arrange | positions on the rotational track of the disc cutter provided in the front of a cutter head, and puts the earth and sand into the opening part alternately along the rotation direction of a cutter head, and puts in front of a cutter head. A plurality of bits are provided at regular intervals along the radial direction and at arbitrary intervals in the circumferential direction. The disc cutter is arranged so that the center of rotation of the disc cutter crosses the center of rotation of the cutter head. have.

In any other publication, as shown in FIG. 1, the center of rotation shaft b of the disc cutter a, which is rotatably provided in front of the cutter head c, is the center of rotation of the cutter head c. It is arrange | positioned so that it may cross | intersect d), and it is comprised so that a cutting blade may excavate while rotating according to rotation of the cutter head c.

In the conventional disc cutter, however, as the cutter head c rotates in the direction of the arrow d as shown in FIG. 2, the disc cutter (c) rotates in the direction of the arrow e. The front half of a) wants to enter the inside of the rotation, and the rear half wants to go out of the rotation.

Therefore, the front half of the disc cutter a receives the transverse load from the inner circumferential side and the rear half from the outer circumferential side.

However, although the front half of the disc cutter (the oblique part in FIG. 2) is in contact with the ground to be excavated, the rear half of the disc cutter is already in the excavated groove because the front half of the disc cutter (a) has already been excavated. Rarely touches.

Therefore, the front half of the disc cutter a receives a greater lateral load than the inner circumferential side, whereas the rear half receives almost no lateral load, so the lateral load distribution of the disc cutter a becomes like the diagram on the right in FIG.

That is, during tunnel excavation, a large unloading load always acts on the front half of the disc cutter a than the inner circumferential side, and as a result, there is a drawback that the life of the bearing supporting the shaft of the disc cutter a is prematurely reduced. have.

In addition, the disc cutter a is twisted by the ground while receiving a large lateral load from the inner circumferential surface side, so that a relative lateral sliding motion occurs between the blade edge of the disc cutter a and the ground. Abrasion is not uniform on the outer circumferential side, so-called uneven wear occurs.

Due to this uneven wear, the life of the disc cutter a is shortened, and this phenomenon is remarkable in the disc cutter a having a small radius of rotation provided near the center of the cutter head c.

Since the disc cutter a on the outer circumferential side is in a state close to linear digging, uneven wear due to unloading is not easily generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the disk cutter apparatus of a tunnel pulverizer which reduces the side load acting on the disc cutter by offsetting (rotating) the center axis of rotation of the disc cutter from the center of rotation of the cutter head is provided. It aims at providing the life improvement of a disk cutter by providing it.

In order to achieve the above object, the present invention relates to a tunnel excavator in which a plurality of disc cutters are rotatably supported on a front surface of a cutter head rotatably provided in a front portion of an excavator body, wherein the cutter head is rotated. (B), and the center axis vector of the cutter head (from the excavator shaft toward the cutting blade side) when the disc cutter comes into contact with the ground to be excavated and rotates. C) When the vector E is orthogonal to both the rotation axis vector B of the disc cutter and the center axis vector C of the cutter head and is directed from the center axis of the cutter head to the rotation axis of the disc cutter, (E) Of the at least one disc cutter so that the internal product F = E × B and the internal product F · C = (E × B) · C of the cutter head's rotation axis vector (C) are positive. It is to arrange the rotation axis.

With the above configuration, the lateral load applied to the inside of the disc cutter is reduced, the lateral load is substantially balanced at the inside and the outside, and the size of the load itself to be distributed is also reduced, so that the disc cutter is supported by the lateral load. This can prevent the bearing from prematurely breaking or uneven wear of the disc cutter.

EXAMPLE

An embodiment of the present invention will be described in detail with reference to the drawings shown below in FIG.

FIG. 3 is a front view of the tunnel excavator, and reference numeral 1 in this figure is a cutter head rotatably installed in the direction of an arrow A on the front surface of the excavator body, which is not shown in the drawing, (2) Denotes a plurality of disc cutters rotatably supported on the front surface of the cutter head 1.

These disc cutters 2 have a main plate egg shape in which the outer circumferential portion is formed in a substantially mountain shape, and is disposed on the entire surface of the cutter head 1 as follows.

That is, as shown in FIGS. 4 and 5, when the cutter head 1 rotates in the direction of the arrow A, the rotation axis vector when the disc cutter 2 contacts and rotates on the ground to be excavated ( (B) and the rotation axis vector (B) of the disc cutter (2) and the cutter (1) in the direction of the central axis vector of the cutter head 1 (toward the cutting blade from the excavator side). When (E) is a vector orthogonal to both of the center axis vectors C of the head and directed from the center axis 1a of the cutter head 1 to the center of rotation axis 2a of the disc cutter 2, ( E) and the disc cutter (C) such that the internal product F (E x B) and C of (B) the product F (E x B) and the center axis vector C of the cutter head 1 are positive. The rotation center axis 2a of 2) is arrange | positioned.

That is, as shown in FIG. 3, only α is rearward with respect to the rotation direction A so that the rotation center axis 2a of the disc cutter 2 does not intersect the rotation center axis 1a of the cutter head 1. It is offset and rotatably supported by the bearing which is not shown in figure.

At this time, the offset amount α is the shortest distance between the straight line passing through the center axis 1a of the cutter head 1 and the straight line passing through the rotation center axis 2a of the disc cutter 2, and the disc cutter ( The rotation center axis 2a of the disc cutter 2 is orthogonal to both the rotation axis vector B of 2) and the center axis vector C of the cutter head 1 from the center axis 1a of the cutter head 1. It is equal to the length of the vector (E) towards).

As the offset amount α increases, the lateral load acting on the inner side of the dicker cutter decreases, and the lateral load on the outer side increases.

Therefore, in order to balance the left and right lateral loads, when the outer diameter of the disc cutter 2 is set to (D), 0.01 α / D About 0.2 (a is made into 1%-20% of outer diameter D) is the most suitable.

Next, the operation will be described. When the cutter head 1 is excavated while being rotated in the direction of the arrow A, the rotation center axis 2a of the disc cutter does not intersect with the rotation center axis 1a of the cutter head 1. Since only the α is offset rearward with respect to the rotation direction A, as shown in FIG. 6, the lateral load applied to the inside of the disc cutter 2 (the central axis of the cutter head 1) is reduced, Lateral loads are approximately balanced on the outside and inside.

On the right side of FIG. 6, the distribution of the lateral loads received by the disc cutter 2 is shown. Compared with the conventional one shown in FIG. 1, the absolute value of the lateral loads is smaller, and the lateral loads are balanced on both the left and right sides. have.

Thereby, it is possible to prevent the disc cutter 2 from unevenly worn or the bearing from being damaged early due to the uneven load.

FIG. 7 is a diagram comparing the distribution of the lateral load acting on the blade edge of the disc cutter 2 with the present invention and the non-offset (conventional). FIG. 8 shows the disc cutter 2 Is a diagram indicating that the combined force of the lateral load is reduced by offsetting the horizontal load. In FIG. 8, the abscissa is the ratio of the offset amount to the disc diameter, and the ordinate is the normalized value. The average of the lateral load is displayed, and the case where the diameter of the disc cutter 2 is 305 mm and the cutting depth is 8 mm is shown.

As evident in FIG. 8, by appropriately setting the offset amount α of the disc cutter 2, the average of the lateral loads can be made approximately zero, and the maximum value of the lateral loads can be reduced.

In the above embodiment, the whole of the disc cutter 2 is offset, but it is also possible to offset a part of the disc cutter 2, in particular, by offsetting the disc cutter 2 on the center side of the cutter head 1 that is likely to cause uneven wear. The disc cutter 2 on the outer circumferential side may be attached without offset as in the prior art.

The present invention, as described in detail above, is applied to the inside of the disc cutter by attaching the disc cutter to the front of the cutter head so that the center of rotation of the cutter head and the center of rotation of the disc cutter do not intersect. Lateral loads are reduced, while lateral loads are approximately balanced at the inside and outside, and the magnitude of the loads being distributed is also small.

As a result, it is possible to prevent the bearings supporting the disc cutters from rotating prematurely due to the uneven load, and the disc cutters are not to be worn out unevenly, thereby improving the life of the disc cutters.

In addition, since the number of times of replacement of bearings and disc cutters is reduced, the time and labor required for replacement can be reduced, and the operation rate of the excavator is increased, so that the construction period can be shortened.

Claims (2)

In a tunnel excavator in which a plurality of disc cutters 2 are rotatably supported on the front surface of the cutter head 1 rotatably provided in the front part of the excavator body, when the cutter head 1 is rotated, the disc cutter is rotated. The rotation axis vector (holding in the right screw direction) when rotating in contact with the ground to be excavated by (2) is set to (B), and the central axis vector of the cutter head (holding in the direction from the excavator side to the cutting blade side) is ( C), the disk cutter 2 of the disk cutter 2 is rotated at right angles to both the rotation axis vector B of the disk cutter 2 and the center axis vector C of the cutter head. When the vector toward the rotation axis 2a is (E), the internal product F = E × B of (E) and (B) and the internal product F * C = (E × B) of the central axis vector (C) of the cutter head. Tunnel drilling characterized in that at least one rotation axis 2a of the disc cutter 2 is disposed so that C is a positive value. Of the cutter head. The outer diameter of the disc cutter 2 according to claim 1, wherein the shortest distance between the straight line passing through the center axis 1a of the cutter head 1 and the straight line passing through the center of rotation axis 2a of the disc cutter 2 is determined. A cutter head device for a tunnel excavator, comprising 1% to 2% of (D).