JPH0442392Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a drum cutter for an underground excavator, which is suitable for use in constructing, for example, an extremely thick and deep underground continuous wall.

[Conventional technology]

In FIG. 4, what is generally designated by the reference numeral 1 is an underground excavator. This underground excavator (hereinafter abbreviated as "excavator") 1 is equipped with a drum cutter 2 for ground excavation at the bottom, and is suspended and moved vertically downward with the drum cutter 2 facing downward. An excavation groove H is excavated in the ground G by this method. Although not shown, the excavator 1 is suspended from a movable platform such as a tower, for example, on the ground. By the way, Figure 4 shows the construction of an ultra-thick-walled, deep underground continuous wall, and the following element E ₂ is formed between the two preceding elements E ₁ and E ₁ that have already been formed. The figure shows the ground G between the preceding elements _E1 being excavated by the excavator 1. This excavation is performed in stabilized liquid A, and after the excavation, concrete is poured into the excavated trench H that has been formed. By joining the elements E in the lateral direction in this way, a diaphragm wall is constructed. The preceding element _E1 was also constructed by excavating the ground G with the excavator 1 and pouring concrete C into the excavated groove H. Also, like this, the preceding element
When excavating for the trailing element E 2 between E _{1 and 2} , in order to strengthen the integration between the leading element E ₁ and the trailing element E ₂ , excavate the ground G at the same time as excavating both the leading elements E. ₁ , and the connecting end face of concrete C that constitutes _E1 will also be cut.

Conventional drum cutter 2 in the excavator 1
As shown in Figure 5 (bottom view), there are two parallel
It is composed of a drum body 3 that rotates around book shafts 6, 6, and a plurality of blade bodies 4 protruding from the outer peripheral surface 3a of the drum body 3. By rotating the drum body 3, the blades 4 rotates and the ground G is excavated.
In the illustrated example, the drum cutter 2 has respective shafts 6,
There are 2 for each 6, that is, 4 in total. The blade body 4 provided on the outer circumferential surface 3a of the drum body 3 is a plate-shaped body formed in a shape suitable for cutting as shown in FIG. 6, and has a cutting edge 5 formed at its tip. The drum body 3 is arranged spirally as shown in FIG. Further, the two shafts 6 are designed to rotate in opposite directions to each other as shown by the arrows in FIGS. 4 and 5, and together with the action of the helical arrangement of the blade 4, a Debris, etc. are discharged in the 6 direction of the axis 4
The drum cutters 2 are arranged so that they can easily gather at the center of each drum cutter 2. A suction port 10 of a discharge pipe 9 is opened in the center of the four drum cutters 2 to suck up gravel and the like generated by cutting to the ground together with the stabilizing liquid A.

Furthermore, ring cutters 7, 7 and wing cutters 8, 8 are provided between the two drum cutters 2, 2 provided coaxially to take charge of excavating the ground in areas not excavated by both drum cutters 2. However, the explanation of these items will be omitted here.

[Problem that the invention attempts to solve]

By the way, the conventional drum cutter 2 described above has the following disadvantages.

That is, the blade body 4 of the drum cutter 2 is plate-shaped as described above, and the drum body 3
Since the entire part is fixed to the cutting edge 5,
In addition to the fact that certain parts are constantly worn and durability is poor, the vibrations caused by the blade body 4 are directly transmitted to the excavator 1, causing large vibrations in the entire excavator 1 and adversely affecting various control devices, etc. Furthermore, since the blade body 4 is attached to the drum body 3 by welding such as brazing, repair and replacement are time-consuming.

In addition, at least two blade bodies 4 are arranged on the same circumferential line so that even if one of the blade bodies 4 is damaged during cutting, there will be no uncut portion. In other words, to explain using FIG. 5 as an example, the circumferential line c on which a certain blade 4a is arranged
In addition to this blade 4a, at least one other blade 4b is provided on the top. In addition, the plate-shaped blade 4 has a relatively large length, that is, a dimension in the direction of rotation, in order to ensure its strength. That is, a large number of wide blade bodies 4 are provided on the outer circumferential surface 3a of the drum body 3, and due to these effects, the movement of the cutting debris in the axial direction is hindered, and the ground G is of soft soil. In particular, if the material is clay-like, the clay, etc. will adhere to the side surface of the blade 4, and will eventually adhere thickly to the outer periphery of the drum body 3, resulting in an extremely low excavation efficiency. It was happening.

This idea was made in view of the above circumstances.
The object of the present invention is to provide a drum cutter for an underground excavator that not only exhibits excellent cutting performance but also has excellent durability, the blade body is easy to repair, and generates as little vibration as possible. .

[Means for solving problems]

The present invention provides a drum cutter for an underground excavator that includes a drum body that rotates around an axis and a plurality of blade bodies that protrude from the outer peripheral surface of the drum body to excavate the ground. a conical bit having a conical body with a conical front end and a cutting edge at its tip; and a holder for holding the conical bit at a predetermined angle with respect to the outer peripheral surface of the drum body. Further, the cutting edge is formed to be eccentric with respect to the holding part of the conical bit held by the holding body, and the conical bit is rotatable about the axis of the holding part and rotated around the axis of the holding part. It is characterized by being held in a state that allows movement in the direction.

[Effect]

Conical bits generate vibrations in the axial direction when they collide with the workpiece during cutting (excavation), which produces a hammer effect, and at the same time absorbs the impact during cutting to suppress chatter vibrations and the like. Further, the eccentrically formed blade body receives a rotational moment due to the eccentricity during cutting, causing the conical bit to rotate around the axis, thereby delaying wear of the cutting blade. Furthermore, the conical bit can be attached to and detached from the holder, making it easy to repair and replace.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a part of a drum cutter 12 for an underground excavator according to an embodiment of the present invention. An example of application to an excavator 1 is shown.

The drum cutter for an underground excavator (hereinafter abbreviated as "drum cutter") 12 includes a drum body 3 which has a cylindrical shape and is driven to rotate around its central axis, and a drum body 3 disposed on the outer circumferential surface 3a of the drum body 3. multiple blade bodies 1
It is composed of 3. The drum cutter 12 is
Similar to the conventional drum cutter 2 constituting the underground excavator 1 in this embodiment, it is designed to rotate around two parallel shafts 6, 6, and has two parallel shafts 6, 6. There are four in total.

As shown in FIG. 2, the blade body 13 has a conical front end and a cutting edge 14 at the tip.
The conical bit 15 is comprised of a conical bit 15 having a diameter of 15 mm, and a holder 16 for holding the conical bit 15 at a predetermined angle with respect to the outer circumferential surface 3a of the drum body 3. Here, the cutting edge 1
4 is a conical bit 15 formed eccentrically with respect to a holding portion 15a held by the holding body 16. The holding body 16 is the drum body 3
It is firmly fixed to the outer circumferential surface 3a by means such as welding. Further, as shown in FIG. 2, the conical bit 15 is prevented from coming off by forming a stepped portion 17 at the front end of the holding portion 15a and by attaching a ring pin 18 near the rear end. However, the step portion 17 and the ring pin 18
By setting the dimension between them to be slightly larger than the holding length by the holding body 16, the conical bit 15 can freely rotate around the axis in its holding part 15a, and is allowed to move slightly in the axial direction. It is configured like this. Further, in this embodiment, the conical bit 15 of the blade body 13 has an angle α of 55° with respect to a tangent of the outer circumferential surface 3a at the attachment portion of the conical bit 15, as shown in FIG.

Next, FIG. 3 shows the blade 1 constructed as described above.
The manner in which the drum bodies 3 are arranged on the outer circumferential surface 3a of No. 3 is shown with the outer circumferential surface 3a developed into a planar shape. In this way, the blade bodies 13 are arranged in two spirals with respect to the drum body 3, and the interval between the blade bodies 13 in the lateral direction (width direction of the outer circumferential surface 3a) is one revolution of the drum body 3. When this is done, it is set so that the cutting surface (cutting surface) corresponding to the outer circumferential surface 3a is uniformly cut without leaving any uncut parts. As can be seen from the figure, only one blade body 13 is provided on the same circumferential line. Furthermore, in this embodiment, the angle β formed by the blade body 13 with respect to the rotating direction of the drum body 3 is 8°.
It is set to .

Next, the operation when excavating the ground G with the drum cutter 12 for an underground excavator having the above structure will be explained.

As the drum body 3 rotates, its outer peripheral surface 3
A plurality of blade bodies 13 provided at a rotate, and the conical bit 15 excavates (cuts) the face of the ground G one after another. At this time, conical bit 1
Since the conical bit 5 is held by the holder 16 in a state where it is allowed to move in the axial direction as described above, the impact when the conical bit 15 collides with the face causes the conical bit 15 to vibrate in the axial direction. This so-called hammer action accelerates cutting and realizes extremely efficient cutting. This action is caused by the conical bit 15 functioning as a vibrating body.
However, it is shaped like a round bar with a conical end.
Since it has a certain amount of mass, it appears more noticeable. Moreover, cutting vibrations such as so-called chatter are caused by this conical bit 15.
The vibrations absorbed by the axial movement and transmitted throughout the device are significantly reduced compared to conventional configurations. Furthermore, the conical bit 15 is attached to the holding body 16.
Since the conical bit 15 is rotatable, it rotates due to friction with the cutting rock when it collides with the face. Moreover, here, since the cutting edge 14 at the tip of the conical bit 15 is eccentrically formed with respect to the holding part 15a, a rotational moment is generated in the conical bit 15 due to this eccentricity, and a larger rotational force is generated in addition to the rotation due to the friction described above. can be obtained. Needless to say, the rotation of the conical bit 15 referred to here does not mean that the conical bit 15 makes a circular motion of one rotation or more, but rather that it changes the angle around its axis by several tens of degrees to half a turn. There is. By constantly rotating the conical bit 15 randomly in this way, the cutting edge 1 of the conical bit 15
4, constant wear of certain parts is prevented and the cutting ability can be exhibited for a long period of time.
Furthermore, in the embodiment, the conical bit 15 is
Since the shaft is configured to have a predetermined angle β with respect to the rotational direction of the drum body 3, the rotation of the conical bit 15 is further promoted. Due to the improved durability and cutting ability of the blade body 13, the blade body 13 has a third
As shown in the figure, it is possible to arrange only one on the same circumferential line. In other words, the number of blade bodies 13 can be significantly reduced compared to the number of conventional blade bodies 4. Also, conical bit 15
can be easily removed from the holder 16 by removing the ring pin 18, and its repair and replacement are extremely easy.

By the way, in this embodiment, the drum cutter 1
2 is configured to have two shafts as described above, and the two shafts 6, 6 rotate in opposite directions to each other so as to rotate inwardly. In other words, together with the effect of the spiral arrangement of the blades 13, the cutting debris such as gravel is collected at the center of the four drum cutters 12 where the discharge pipes 9 are located. At this time, the excavated debris moves across the outer peripheral surface 3a of the drum body 3 in its width direction (axis 6 direction). The conventional drum cutter 2
In this case, the blade 4 was plate-shaped and two or more pieces were arranged on the same circumferential line, which not only hindered the lateral movement of the cutting chips but also caused clay etc. to adhere to the sides of the blade 4. Eventually, a thick layer was formed over the entire outer circumferential surface 3a, leading to a decrease in cutting efficiency. However, according to the blade 13, in addition to the reduction in the total number of layers, the three-dimensional and curved side shape of the blade prevents the adhesion of clay. is prevented as much as possible, and a decrease in cutting performance caused by this can be prevented. In addition, when cutting debris moves laterally as described above, this horizontally moving cutting debris
Conical bit 15 with eccentric configuration of cutting edge 14
is given a rotation due to the eccentric configuration, and
Particularly when the ground G to be cut is hard, such as rock, the lateral moving gravel, etc.
by applying vibration to the conical bit 15 and the holding body 16.
It is possible to prevent adhesion.

As mentioned above, the drum cutter 12 according to the present invention is suitable for being attached to an underground excavator used especially when constructing a deep underground continuous wall. When building,
As described above, the ground G is excavated while cutting the hard concrete C on both sides. It is assumed that the ground G is mainly soft, but in any case, it must be able to fully demonstrate its function on both soft and hard surfaces. 12
can exhibit excellent cutting performance in both cases.

In addition, in the example, conical bit 15
is set at an angle of 55° with respect to the outer circumferential surface of the drum body 3 and 8° with respect to the rotational direction of the outer circumferential surface of the drum body 4, which was obtained through experiments by the applicant and others. This is based on the knowledge obtained from 2 above.
Particularly excellent cutting performance can be obtained by approximately setting the two angles α and β to the above values. However, the values of the angles α and β are not limited to these values. In addition, the excavator 1 shown in the above embodiment
Although the drum cutter 12 includes a ring cutter 7 and a wing cutter 8, a blade body similar to the blade body 13 constituting the drum cutter 12 may be provided on the ring cutter 7, etc., for example. Further, in this embodiment, an example is shown in which the drum cutter 12 is applied to the underground excavator 1, but the drum cutter for an underground excavator according to the present invention is not limited to that of the underground excavator 1. Needless to say.

[Effect of idea]

As explained above, according to the drum cutter for an underground excavator according to the present invention, when excavating the ground,
The conical bit generates axial vibration to promote cutting by hammer action, and this axial movement absorbs chatter vibrations during cutting and prevents vibrations of the entire excavator. Moreover, due to the eccentric formation of the cutting edge, conical bits receive rotational moment during cutting, causing rotation around the axis, which delays the wear of the cutting edge and provides excellent cutting performance and durability. In addition, since the conical bit can be attached to and removed from the holder, it can be repaired very easily, and has various other excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a part of a drum cutter for an underground excavator according to an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged side view showing a blade body of a drum cutter for an underground excavator according to an embodiment, and shows the manner in which the blade bodies are arranged on the outer peripheral surface of the drum body when the drum body is unfolded in a flat state. The plan view and FIG. 4 are an overall front view showing an underground excavator according to an embodiment together with the ground etc.;
FIG. 5 is a bottom view showing an example of a conventional drum cutter for an underground excavator, and FIG. 6 is a front view showing a part of the conventional drum cutter for an underground excavator. 1... Underground excavator, 3... Drum body, 3a...
Outer peripheral surface, 6... Shaft, 12... Drum cutter for underground excavator, 13... Blade body, 14... Cutting blade, 15...
Conical bit, 15a...holding part, 16...holding body, G...ground.

Claims (1)

[Scope of utility model registration request] A drum cutter for an underground excavator configured with a drum body that rotates around an axis and a plurality of blade bodies that protrude from the outer peripheral surface of the drum body and excavate the ground, the blade bodies having a front end The conical bit is formed into a conical shape and has a cutting edge at its tip, and a holder that holds the conical bit at a predetermined angle with respect to the outer peripheral surface of the drum body, Furthermore, the cutting edge is formed eccentrically with respect to the holding part of the conical bit held by the holding body, and the conical bit is rotatable about the axis of the holding part and in the axial direction of the holding part. A drum cutter for an underground excavator, characterized in that it is maintained in a state that allows movement.