JPH02210187A - Multishaft excavator - Google Patents

Abstract

PURPOSE:To enable facilitation of excavation by a method wherein a multishaft excevator is provided at its tip with an excavating head, and a plurality of excavating shafts movable vertically in parallel, and the head of the excavating shaft of a central part is protruded and vertically expandable. CONSTITUTION:A plurality of excavating shafts are provided, and an expansion and contraction part 6 having structure in which when a plurality of continuous holes are bored at a time, rotational drive from a drive part 4 is transmittable as at least an excavating shaft at a central part is elevated by means of an oil pressure is provided. Through operation of the expansion and contraction part 6 formed with a hollow piston, a piston ring, a cylinder case, and a transmission pipe. an excavating head 2 at the tip of the excavating shaft at the central part is further protruded than other excavating heads 2 to bore a small hole ahead of other holes. This constitution improves vertical precision during excavation of a subsequent large hole, and enables the smooth progress of a work in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-shaft excavator that has a plurality of auger shafts and is capable of drilling a plurality of consecutive holes at once in foundation work and the like.

[Prior art]

Conventionally, in this type of multi-shaft excavator, each excavation head at the tip of each excavation shaft is mounted at a different position in the vertical direction of the excavation shaft in the vicinity of the respective excavation heads. It is generally known that excavation cross sections can be overlapped with each other to allow excavation of a large cross section at a time.

[Problems to be solved by this invention]

However, each excavation head of this conventional multi-axis excavator performs excavation with its excavation cross sections largely overlapping each other at nearby positions. As a result, a hole with a large cross section is excavated all at once, which increases the resistance, making it difficult and difficult to perform excavation particularly in hard ground, making the work of drilling a hole with a large cross section time-consuming.

In addition, if each drilling head performs drilling with its excavation cross-section largely overlapping each other, the tip of each drilling head will have a large clearance, which causes problems such as worsening the vertical accuracy of the hole. .

This invention was devised in view of the above-mentioned circumstances, and its purpose is to be able to perform the drilling work of large-section holes in a short time, to improve the vertical accuracy of the holes, and to improve the vertical accuracy of the holes. An object of the present invention is to provide a multi-axis excavator that can reliably perform the following operations.

[Means to solve the problem]

According to the present invention, at least the central excavation shaft of the multi-axis excavator is disposed to protrude from the excavation tip of each excavation head, and is freely expandable and retractable in the vertical direction.

The protruding drilling head of the drilling shaft can be used to drill a small-diameter hole in advance, and the surrounding area of the small-diameter hole can be used as soft soil to facilitate drilling with the remaining drilling shafts. It has been made possible to do so.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

A multi-shaft excavator 1 (see FIG. 1) includes a plurality of excavating shafts 3 having excavating heads 2 at their tips, which are arranged parallel to each other along the vertical direction. At least the central excavation shaft 3 is arranged to protrude from the excavation tip of each excavation head 2, and is configured to be freely expandable and contractible in the vertical direction.

In this embodiment, three excavation shafts 3 are arranged and attached to the drive unit 4 at the upper end, with excavation shafts 3.3 on both sides and a telescopic excavation shaft 3.3 in the center. , the direction of rotation is changed as shown by the arrow. Also, each excavation axis 3
Both spacing holding parts 5, 5 directly above and above the excavation head 2 of
In between, there are stirring screws 1 whose stirring cross sections overlap each other.
4 (a stirring blade may also be used).

The central telescopic excavation shaft 3° is telescopic by a telescopic part 6 provided below the drive part 4.

That is, the excavation shaft 3' below the extendable part 6 is movable in the vertical direction. Along with this vertical movement, the excavation shaft 3' (see Fig. 2), on which the stirring screw 14 between the two spacing holding parts 5, 5 is provided, changes the excavation axis 3° and the excavation axis 3'. It is provided on the outer periphery of ", and has a double pipe type including an outer pipe 7 in which the stirring screw 4 is formed.

In addition, the abutment surface between the excavation shaft 3' and the outer tube 7 is formed in a hexagonal shape, allowing the excavation shaft 3' to move independently of the outer tube 7 and transmitting the rotational force of the excavation shaft 3' to the outer tube 7. It is now possible to transmit.

The telescopic part 6 (see Fig. 3) includes a hollow piston 8 into which the excavation shaft 3° is fitted and whose upper end is connected to the rotating shaft 4a from the drive part 4, and a hollow piston 8 provided in the center of the hollow piston 8. A cylinder case 10 is provided at the upper position of the hollow piston 8 and houses the piston ring 9, and a cylinder case 10 is provided at the lower end of the cylinder case 10 and is located below the hollow piston 8. It consists of a transmission vibrator 11 connected at 3 degrees.

The abutment surface between the excavation shaft 3° and the hollow piston 8 is formed in a hexagonal shape, allowing the excavation shaft 3° to move independently of the hollow piston 8 and to transfer the rotational force of the hollow piston 8 to the excavation shaft 3°. It is now possible to transmit. Further, by injecting pressure oil or the like into the cylinder case 1θ, the excavation shaft 3' can be changed from the shortened state shown in FIG. 1 to the extended state shown in FIG.

To explain in detail the expansion and contraction movement of this excavation axis 3°, when pressure oil etc. is injected into the cylinder case 10 below the piston ring 9 (see Fig. 4), the hollow piston connected to the rotating shaft 4a of the drive unit 4 Since the piston ring 9 of 8 is fixed, the cylinder case 10 moves downward. When the cylinder case 10 moves downward, the excavation shaft 3' moves downward via the transmission vibrator 11 attached to the lower end of the cylinder case 10, thereby performing an extension operation.

Conversely, the cylinder case 1 above the piston ring 9
When pressurized oil or the like is injected into the cylinder case 10 (see Fig. 3), the piston ring 9 of the hollow piston 8 connected to the rotating shaft 4a of the drive unit 4 is fixed.
moves upward. When the cylinder case 10 moves upward, the excavation shaft 3' moves downward via the transmission vibrator 11 attached to its lower end, thereby performing a shortening operation.

Drilling using the multi-axis excavator 1 having such a configuration is first carried out in soft soil 12 by suspending the multi-axis excavator 1 and rotating each excavation shaft 3, as shown in FIG. It will be done. When the soft ground 12 is excavated in this manner and the hard ground 13 is reached, the central excavation shaft 3' is extended (moved downward) by the operation of the above-mentioned telescopic portion 6.

Next, as shown in FIG. 6, a small diameter hole is pre-drilled at an angle of 3° with the excavation axis, and the excavation axis 3' is shortened (moved upward) while blowing out cement milk from a cement milk blowing part (not shown).

Next, as shown in Fig. 7, the excavation shaft 3.
Drill a large diameter hole. At this time, since a small-diameter hole has been previously excavated with the drilling shaft 3, the area around the small-diameter hole becomes soft and has little resistance, allowing the large-diameter hole to be excavated smoothly.

Next, as shown in FIG. 8, the excavation shaft 3' is moved downward again to pre-drill a small diameter hole, and as described above, a large diameter hole is excavated using the excavation shafts 3 on both sides.

By repeating this kind of excavation work,
Excavation of large diameter holes can be carried out smoothly and in a short time.

In addition, the rotation direction is different between the drilling shafts 3.3 on both sides and the central drilling shaft 3', and the drilling shafts 3.3 and 3' are guided into the small diameter hole previously drilled with the drilling shaft 3°. This eliminates this problem and improves the vertical accuracy of the drill hole.

Although the multi-shaft excavator of the present invention has three excavation shafts in the above-described embodiment, it may have more than three excavation shafts. In addition, the drilling shaft for drilling the preceding small diameter hole is not limited to the one in the center as in the above-mentioned embodiment.
Multiple pieces on both sides may be used.

〔Effect of the invention〕

In the multi-axis excavator of the present invention, at least the central excavation shaft of each of the excavation heads provided at the tips of the plurality of excavation axes arranged parallel to each other along the vertical direction is connected to each excavation shaft. It is characterized by being arranged so as to protrude from the excavation tip of the head and being able to expand and contract in the vertical direction.

According to this configuration, by expanding and contracting the excavation head of the protruding excavation shaft, a small diameter hole can be excavated in advance.

Therefore, the surrounding area of the small diameter hole is made soft, and the remaining excavation shafts can easily perform excavation. As a result, large-diameter holes can be excavated smoothly and in a short time using a multi-shaft excavator without increasing the resistance caused by the multi-shafts and making it difficult to dig.

Furthermore, since a small diameter hole can be drilled in advance using the protruding drilling shaft, the remaining drilling heads can be guided by the small diameter hole without slippage, and the vertical accuracy of the large diameter hole can be improved.

As described above, according to the present invention, a hole having a large cross section can be reliably excavated smoothly and in a short time without deteriorating the vertical accuracy.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted front view showing a multi-shaft excavator of the present invention;
2 is an enlarged sectional view taken along the line A-A in FIG. 1, FIG. 3 is an enlarged sectional view of section B in FIG. 5 to 8 are process diagrams showing excavation work by the multi-shaft excavator of the present invention. 1...Multi-axis excavator, 2...Drilling head, 3,3°・
... Excavation axis, 4... Drive section, 5... Spacing holding section, 6
... Telescopic part, 7 ... Outer tube, 8 ... Hollow piston,
9... Piston ring, 10... Cylinder case, 11... Transmission pipe, 12... Soft soil, 13.
...Hard ground, 14...Stirring screw chart chart chart chart chart chart chart

Claims (1)

[Scope of Claims] In a multi-shaft excavator in which a plurality of excavation shafts each having an excavation head at the tip are arranged parallel to each other along the vertical direction, at least the excavation shaft in the central portion is connected to each of the excavation heads. A multi-axis excavator characterized by being arranged so as to protrude from the tip of the excavator and being able to expand and contract in the vertical direction.