JP4197479B2 - Drilling stirrer - Google Patents

Description

  The present invention relates to an excavation and agitation device used when excavating and agitating a pile hole and pushing a pile into the hole to create a support pile.

  When installing underground piles, there is an excavation construction technique in which a stirring portion is formed in the ground and the pile is pushed into the stirring portion. In this technology, using a drilling shaft consisting of a drill bit, earth auger, drilling stirrer, etc., the drilling fluid is injected into the construction ground while drilling to a predetermined depth by forward rotation, Form. The drilling fluid reduces excavation resistance of the ground and mud in the hole to prevent the collapse of the hole wall. After repeatedly raising and lowering the excavating shaft, a rooting bulb is built at the bottom of the excavation while injecting a root hardening liquid at a predetermined depth.

  Next, a soil cement-like stirring part is formed in the ground while the excavating shaft is pulled up and the pile periphery fixing liquid is injected and stirred. The stirrer generated by stirring and mixing the pile periphery fixing liquid and excavated soil fills the space between the hole wall and the pile peripheral surface, and ensures the frictional force and horizontal resistance force of the pile peripheral surface. Push the pile into the excavation hole, fix the tip of the pile to reach the bulb position, and install the pile.

  In the above prior art, since the earth auger moves up and down in the ground while rotating the spiral blade, the earth and sand slides on the surface of the auger blade, and the stratum simply slides on the spiral surface, and thus receives almost a stirring action. Absent. Therefore, a sufficient stirring part cannot be formed in the ground. For this reason, lump of earth and sand etc. intervene, uniaxial compressive strength as a hardened body of pile circumference fixing liquid is reduced, adhesion between the pile and the ground around the pile is inferior, and expected sufficient bearing capacity is expected There was a problem that I couldn't. There is an underground pile creation method that solves such problems (for example, see Patent Document 1).

  The technology reverses the rotation of the agitating blades protruding from the outer periphery of the excavating shaft, injects the pile periphery fixing liquid, agitates the ground, and places the agitating part where the underground pile should be laid in the ground It is the formation method of the underground pile which forms and then sinks a pile in this stirring part. According to this method, a very well stirred portion can be formed in the ground.

There is also a stirring blade that rotates forward and backward with a single shaft used for ground improvement work (see, for example, Patent Document 2). Specifically, the technology replaces the conventional excavation blade shaft and uses it at the lower end of the excavation shaft, and interposes the intermediate portion of the excavation shaft to bring the ground around the pile into close contact with the pile. It is not intended for the purpose of forming the bulb bottom. In addition, the driving gear, the intermediate gear, and the driven gear have a structure in which the three gears are directly meshed with each other, and it is difficult to accurately secure and maintain such gear meshing with an excavation shaft with impact, With this structure, it is difficult to seal, and it is not easy to prevent intrusion and biting of foreign matter and liquid, and there is a problem in practical use.
Application for Japanese Patent Application No. 2002-079116 JP 7-197446 A (page 1-2, FIG. 1)

  As mentioned above, there is a stirring blade that rotates forward and backward with a single shaft used for ground improvement work as described above, but it is not for attaching the ground around the pile to the pile by interposing it in the middle part of the drilling shaft The gear train has a structure in which the gear train is directly meshed, which is not suitable for use in an excavation shaft with impact, and there is a problem that it is not easy to prevent foreign matter and liquid from entering and biting.

  The present invention improves on such a device, injects the above-mentioned pile circumference fixing liquid, stirs the ground, and brings the pile circumference of underground piles such as node piles into close contact with the ground to increase the support force. It aims at providing the excavation stirring apparatus which can be used suitably.

  The technical means of the present invention for solving the above-mentioned problems is a device interposed in an intermediate portion of a drilling shaft for rotating excavation of a pile hole, the chain wheel mounted on the main shaft of the device, and the chain A driven vehicle driven from a vehicle via a chain, a pinion coaxial with the driven vehicle, a large gear meshing with the pinion and rotatably fitted on the main shaft, and a stirring blade attached to the large gear; An excavation and agitation device comprising a casing that covers the chain wheel, a driven vehicle, a pinion, and a large gear, and that is externally fitted to the main shaft via a seal device and has a reaction force supporting blade projecting on an outer surface.

  According to the present invention, an excavation stirring device that rotates in reverse with respect to the rotation of the excavation shaft is attached to an intermediate portion of the excavation shaft, and a stirring portion in which the pile periphery fixing liquid is uniformly and sufficiently mixed is formed in the ground. Since a pile is sunk in this stirring part, the adhesiveness of a pile periphery and the ground is excellent, and a pile with a large bearing capacity can be constructed.

  The excavation and agitation device of the present invention uses a chain and a chain wheel for transmitting the rotational force, and uses a mechanism that provides a margin for the transmission mechanism and absorbs the impact, so that the durability of the device is high and smooth excavation and agitation is performed. Can do. In addition, this apparatus has a tight seal structure, mud or the like does not enter the apparatus, and maintenance work is minimized.

  Since the excavation hole is mud during pile construction, it is easy to insert the pile, there is no complicated construction process, and construction management is easy. In addition, the pile laying method using the excavating and stirring device of the present invention is a complete non-striking method, which has low vibration and low noise and does not adversely affect the environment, and can be applied to various ground properties. There is an excellent effect of being able to.

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

  The side view and longitudinal cross-sectional view of the excavation stirring apparatus 10 of this invention were shown in FIG. The excavating and agitating apparatus 10 of the present invention incorporates a main shaft 13 having a male joint 11 at the upper end and a female joint 12 at the lower end. The main shaft 13 is inserted and connected to an intermediate portion of the excavating shaft so as to provide a vertical rotational force. To communicate.

  In the excavation and agitation apparatus 10 of the present invention, a chain wheel 21 is fixed to a main shaft 13 and transmits a rotational force to a driven vehicle 22 via the chain. The chain conduction is preferable because it allows some play in the transmission mechanism, absorbs shock, and does not apply excessive force. A pinion 24 is coaxially attached to the driven vehicle 22. The driven wheel 22 and the shaft 25 of the pinion 24 are supported by bearings provided in the casing 31. The pinion 24 meshes with the large gear 26. The large gear 26 is externally fitted to the main shaft 13 via the bearing 14 and rotates separately from the main shaft 13. A stirring blade 41 is attached to the large gear 26.

  The casing 31 includes a fitting portion 32 that is rotatably fitted to the main shaft 13. The fitting portion 32 slides and rotates on a sleeve 28 that is hard-chrome plated on the shaft side and is sealed by a seal ring 34. It is tightly sealed. Further, the casing 31 is fitted on the boss 27 of the large gear 26 so as to be relatively rotatable, and is completely sealed by a seal ring 33. A pair of reaction force support wings 35 project from the outer periphery of the casing 31.

  When the excavation shaft rotates forward, the main shaft 13 integrally connected to the excavation shaft at the upper and lower ends also rotates in the same manner, and the chain wheel 21 rotates the driven vehicle 22 through the chain. A pinion 24 coaxial with the driven wheel 22 rotates the large gear 26. At this time, if the pair of reaction force support blades 35 are stationary in the soil, the stirring blade 41 attached to the large gear 26 rotates in reverse with respect to the main shaft 13.

  When the pile peripheral liquid is supplied to the reverse rotating portion of the stirring blade 41, a mud-like stirring portion is formed in the pile peripheral portion, and when the pile is subsequently submerged into the ground, the outer periphery of the pile and the ground are firmly bonded. The adhesion and supporting force of the pile can be increased.

It is the side view and longitudinal cross-sectional view which show the excavation stirring apparatus of the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Excavation stirring apparatus 11 Male joint 12 Female joint 13 Main shaft 14 Bearing 21 Chain wheel 22 Driven wheel 24 Pinion 25 Shaft 26 Large gear 27 Boss 28 Sleeve 31 Casing 32 Fitting part 33, 34 Seal ring 35 Reaction force support blade 41 Stirring blade

Claims (1)

  A device interposed in an intermediate portion of a drilling shaft for rotating excavation of a pile hole, a chain wheel mounted on a main shaft of the device, a driven vehicle driven from the chain wheel via a chain, and the driven A pinion coaxial with the car, a large gear meshing with the pinion and rotatably fitted on the main shaft, a stirring blade attached to the large gear, the chain wheel, the driven wheel, the pinion, and the large gear A drilling and agitation device comprising: a casing externally fitted to a main shaft via a seal device and a reaction force supporting blade projecting on an outer surface.

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