JP2012172373A - Ground excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground excavator for uniformly agitating and mixing the inside of an excavation well with a large diameter.SOLUTION: A plurality of agitation blades 6 provided at the tip of an excavator is rotated in an opposite direction to a main shaft 2 through a multi-spindle rotation mechanism 5 by a planetary gear mechanism.

Description

  The present invention relates to a ground excavating machine for excavating the ground in order to construct a soil cement columnar body used in a foundation or the like of a structure in the ground.

In soft ground, etc. where sufficient bearing capacity cannot be expected by using ready-made piles, a soil cement columnar body is constructed in the ground by excavating the ground and stirring and hardening the excavated soil and cement milk. It is common to do.
To excavate the ground, an excavating machine such as an auger machine (also called an earth auger) is usually used. However, if the excavation diameter is large, moving the position many times and excavating will increase the construction cost, so a single motor drives multiple augers and excavates a large diameter with one setup. Various attempts have been made to do it. At that time, if multiple excavation shafts rotate in the same direction, agitation and mixing of the excavated earth and cement milk become non-uniform regardless of excavation, so it is necessary to devise to rotate the multiple excavation shafts in opposite directions. It is.

  Patent Document 1 describes a mechanism that reversely rotates a stirring blade between a tip end portion and an upper portion thereof by a counterclockwise stirring device provided in the vicinity of an excavation head, although it is a single shaft. This will be briefly described with reference to the drawings. In FIG. 6, 2 is a main shaft of the excavating machine, 3 is a blade for excavation at its tip, 6 is a blade for stirring, 7 is a reverse stirring device, and 71 is a reverse stirring blade attached to the outer periphery thereof. Although details are omitted, a reverse rotation mechanism using a planetary gear is built in the reverse rotation stirring device 7, and the reverse rotation stirring blade 71 rotates reversely to the stirring blade 6 attached to the main shaft. . Thereby, excavated earth and sand and cement milk are mixed homogeneously. Patent Document 1 also describes an example in which power is branched from three motor sections of a drilling machine to three auger shafts arranged in a straight line, and the ground is excavated into three cylindrical shapes that lap each other.

  When excavating two adjacent columnar bodies by wrapping each other as in the case of constructing underground walls, the rotation of the auger shaft is synchronized to prevent the respective excavating blades from interfering and damaging. It is necessary to make it. Patent Document 2 describes a mechanism that synchronizes the rotation of two auger shafts driven by their own motors. This will be briefly described with reference to the drawings.

  FIG. 7 is a cross-sectional view of the tuning unit 8 described in Patent Document 2. 2A and 2B are auger shafts, 81 is a bevel gear, 82 is a driven shaft, and 83 is a connecting sleeve. That is, splines are cut at the ends of the driven shafts 82 and 82 of the bevel gears 81 and 81 meshing with the bevel gears attached to the respective auger shafts 2A and 2B. The rotation of the shafts 2A and 2B is synchronized.

Patent Document 3 describes a bucket-shaped movable bottom forming body suspended inside a cylindrical casing body built in the ground, each having an excavation body equipped with a drive motor attached thereto. ing.
Further, Patent Document 4 describes an underground excavator provided with a crushing bit that revolves while rotating, although it is horizontal excavation. FIG. 8 is an explanatory view showing the revolution mechanism, wherein 9 is a planetary gear mechanism, 91 is a rotating body, 92 is a ring gear, and 93 is a pinion gear. When the ring gear 92 is fixed by some means and the rotating body 91 is rotated, the plurality of pinion gears 93 that support the rotating shaft of the rotating body 91 revolve while rotating.

JP-A-10-195923 Japanese Patent Application Laid-Open No. 2002-256587 JP 2003-342946 A JP 2002-138895 A

As described above, there are various mechanisms for rotating in reverse while synchronizing a plurality of axes. However, the counterclockwise stirring device described in Patent Document 1 is a reverse rotation mechanism for one axis, and the purpose is to make the formation vertical in the vertical direction. Thus, it is not directly useful for uniformizing a plurality of axes in the same height plane.
The tuning unit described in Patent Document 2 is an effective technique for a multi-column such as an underground wall, but is not very effective in the case of a single circle large-diameter soil cement columnar body.

Although the structure described in Patent Document 3 is simple in configuration, it requires a large number of motors as many as the number of shafts, which is not preferable in terms of cost.
The planetary gear mechanism described in Patent Document 4 is effective in the case of tunnel excavation where the ring gear can be fixed by pressing against the ground, but there is no suitable ring gear fixing means, and the planetary gear mechanism is excavated. Also from the point that it must be provided at the tip, it cannot be applied when excavating a columnar body in the vertical direction on soft ground.

  An object of the present invention is to solve such problems and to realize a ground excavation machine capable of efficiently performing excavation, agitation, and mixing at low cost by rotating a stirring blade with a plurality of shafts.

  The present invention according to claim 1 is a ground excavating machine used when a soil cement columnar body is constructed by excavating the ground into a columnar shape and curing the soil cement formed by stirring the excavated sediment and cement milk. In addition, one or more stirring blades that can be rotated differently from the main rotation shaft are provided at the tip of the main rotation shaft that is driven by a ground motor and performs excavation by rotation of the excavation blade. It is a ground excavating machine characterized by

The present invention according to claim 2 is the ground excavating machine according to claim 1, wherein the stirring blade rotates through a multi-axis rotating mechanism driven by the main rotating shaft. .
According to a third aspect of the present invention, the multi-axis rotation mechanism includes a gripping means capable of gripping and releasing the main rotation shaft, a sun gear attached to the main rotation shaft, a planetary gear meshing with the sun gear, and these A casing that is rotatable with respect to a main rotating shaft that accommodates a gripping means, a sun gear, and a planetary gear, and a stirring blade is connected to a tip end side of the rotating shaft of the planetary gear, and an outer periphery of the casing The ground excavating machine according to claim 2, wherein a blade for excavation is attached.

  According to the present invention, a ground excavation machine capable of performing excavation, agitation, and mixing efficiently and at low cost by rotating the agitating blades in a direction opposite to the main axis by a plurality of axes is realized. Since the inside of a well having a diameter can be stirred and mixed uniformly, the foundation work in soft ground and the like is made more efficient.

It is a front view which shows the whole ground excavation machine of an Example. It is a longitudinal direction sectional view showing the multi-axis rotation mechanism which is the principal part of the ground excavating machine of the example. It is horizontal direction sectional drawing of the gear part in the multi-axis | shaft rotation mechanism of an Example. It is explanatory drawing which shows the excavation condition in an Example. It is explanatory drawing which shows the stirring condition in an Example. It is a front view near excavation blades showing an example of conventional technology. It is a partial cross section front view of the excavation blade | wing vicinity in the other example of the prior art. It is explanatory drawing which shows the rotation mechanism of the excavation shaft in the further another example of a prior art.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the entire ground excavating machine of the embodiment, P is a drilling well, 1 is a motor provided on the ground portion, 2 is a main shaft (main rotating shaft), 3 is provided at the tip and intermediate portion of the main shaft 2 4 is a soil cement obtained by stirring and mixing excavated earth and cement milk, 5 is a multi-axis rotating mechanism provided at the tip of the main shaft 2, and 6 is provided at the bottom of the multi-axis rotating mechanism 5. The configuration of the stirring blade other than the multi-axis rotating mechanism 5 and the stirring blade 6 is the same as that of the conventional auger machine.

  FIG. 2 is a longitudinal sectional view of the multi-axis rotating mechanism 5 which is a main part of the ground excavating machine according to the embodiment. Reference numeral 51 denotes upper and lower bearings with respect to the main shaft 2, 52 denotes a gripping mechanism, 53 denotes a retaining member, and 54 denotes the main shaft 2. The sun gear 55 is attached to the planetary gear 55, the planetary gear 55 meshing with the sun gear, and the planetary gear 56 is connected to the lower part (tip) of the stirring blade 6 at the rotating shaft. Excavation blades 3 are fixed to the outer surface of the casing of the multi-axis rotating mechanism 5 by welding or the like in a desired direction such as a horizontal direction or a diagonally downward direction. The retaining member 53 is a disk or the like attached to the main shaft 2, and a member for locking the retaining member 53 is provided on the casing side of the multi-axis rotating mechanism 5. FIG. 2 shows an example in which the sun gear 54 has two upper and lower stages, but the same plane may be used as long as the planetary gears 55 do not interfere with each other depending on the reduction ratio.

  The gripping mechanism 52 is arbitrary such as a hydraulic system or a mechanical system, but the multi-axis rotating mechanism 5 is a mechanism that grips or releases the main shaft 2. In the case of a hydraulic system, the spindle 2 is gripped (clamped) using, for example, a hydraulic cylinder device. The multi-axis rotating mechanism 5 rotates integrally with the main shaft 2 in the gripping state, and is free in the released state. Examples of the mechanical system include a known ratchet mechanism. Depending on the direction of the ratchet, it can be synchronized in the forward rotation and free in the reverse rotation. Since forward / reverse conversion of the motor is easy, this method is effective.

  FIG. 3 is a horizontal sectional view of the gear portion. Since the multi-axis rotation mechanism 5 rotates integrally with the main shaft 2 in the gripping state, these gears do not rotate, but in the released state, the planetary gear 55 revolves around the sun gear 54. Actually, the planetary gears 55 rotate in the same position as the sun gear 54 rotates. That is, in FIG. 2, the excavation blade 3 does not rotate due to the resistance of the surrounding soil cement, and only the stirring blade 6 rotates.

  4A and 4B are explanatory views showing a situation when the holding mechanism 52 is holding the main shaft, where FIG. 4A is an explanatory view schematically showing the inside of the excavation well P, and FIG. That is, when the gripping mechanism 52 is gripping the main shaft, the multi-axis rotation mechanism 5 rotates integrally with the main shaft 2, so that predetermined excavation is performed by the outer excavation blade 3. The stirring blades 6 do not rotate, and are urged to excavate in the same direction.

  When the gripping mechanism 52 releases the main shaft 2, even if the main shaft 2 is rotated, the multi-axis rotation mechanism 5 does not rotate due to the surrounding resistance, so that the stirring blade 6 rotates at each position. This situation is shown in FIG. As in FIG. 4, (a) is an explanatory view schematically showing the blade portion, and (b) is an explanatory view schematically showing the inside of the excavation well P. Since stirring is performed not only in the circumferential direction but also in the radial direction, uniform stirring of the soil cement throughout the drilling well is realized.

It is also possible to increase the size of the stirring blade 6 and also use it for excavation. Further, since the position of the stirring blade 6 does not change at the time of release, the mixing condition of the soil cement may be uniform, but this can be solved by frequently switching the mode from gripping to release to gripping.
The gear ratio between the sun gear 54 and the planetary gear 55 may be determined according to the torque required for stirring and the rotational speed. The larger the gear diameter of the sun gear 54, the higher the rotational speed of the stirring blade 6; Further, by replacing the planetary gear with a continuously variable transmission using a chain or a belt, it is possible to change the torque and the number of revolutions and to perform automatic control.

  In addition, although the case where the rotating shaft of the stirring blade 6 is three was shown, at least one stirring blade 6 rotating in the direction opposite to the main shaft is necessary, and the number is arbitrary.

  According to the present invention, a ground excavation machine capable of performing excavation, agitation, and mixing efficiently and at low cost by rotating the agitating blades in a direction opposite to the main axis by a plurality of axes is realized. Since the inside of a well having a diameter can be uniformly stirred and mixed, the foundation work on soft ground and the like is made more efficient, so that it has a remarkable industrial effect.

1 Motor 2 Main shaft
DESCRIPTION OF SYMBOLS 3 Excavation blade 4 Soil cement 5 Multi-axis rotation mechanism 6 Stirring blade 7 Reverse rotation stirring device 8 Tuning unit 9 Planetary gear mechanism 51 Bearing 52 Holding mechanism 53 Retaining member 54 Sun gear 55 Planetary gear 56 Stirring shaft 71 Reverse rotation stirring Blade 81 Bevel gear 82 Drive shaft 83 Connection sleeve 91 Rotating body 92 Ring gear 93 Pinion gear P Drilling well

Claims (3)

  It is a ground excavation machine that is used when building a soil cement columnar body by curing the soil cement formed by excavating the ground into a columnar shape and stirring the excavated earth and cement milk, driven by a ground motor, A ground excavation machine, wherein one or a plurality of stirring blades capable of rotating different from the main rotation shaft are provided at a tip portion of a main rotation shaft that performs excavation by rotation of the excavation blade.   The ground excavation machine according to claim 1, wherein the stirring blade is rotated via a multi-axis rotation mechanism driven by the main rotation shaft.   The multi-axis rotation mechanism includes a gripping means that can grip and release the main rotation shaft, a sun gear attached to the main rotation shaft, a planetary gear meshing with the sun gear, and the gripping means, the sun gear, and the planetary gear. And a casing blade that is rotatable with respect to the main rotating shaft, a stirring blade is connected to a tip end side of the rotating shaft of the planetary gear, and an excavation blade is attached to the outer periphery of the casing. The ground excavation machine according to 2.

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