JP3996925B2 - Telescopic rod for ground improvement equipment - Google Patents

Description

  The present invention relates to a telescopic excavation rod for a ground improvement device used when ground improvement is performed by injecting a ground improvement material into soft ground.

  The conventional telescopic drilling rod has an inner tube on the lower side and an outer tube on the upper side, and the inner tube is inserted into the outer tube in a telescopic manner, and an improved material supply pipe provided inside the outer tube is attached to the head of the inner tube. The tube is sealed and inserted so that it can be inserted into an improved material supply pipe connected to the lower side of the head.

In addition, the upper inner rod is inserted into the lower outer rod so as to be extendable and the lower chemical guide tube provided inside the outer rod is inserted into the upper chemical guide tube inside the inner rod, and the lower chemical guide is provided. Some have a sealing material around the tip of the tube.
JP-A-63-89722 JP-A-9-31965

In the prior art, the material of the inner pipe is steel, so even if the inner surface of the pipe is honed, ground improvement materials such as cement milk and bentonite are always circulated in the pipe. It often occurs or adhesion of ground improvement material occurs.
In addition, even if the V packing used in many cases is applied to the seal of the inner tube, the V packing is compressed by applying a certain pressure with a bolt during assembly, and the seal is easily sealed. Since it is necessary to maintain a sealing property by being in close contact with the surface, leakage due to loosening of the V-packing is likely to occur even if it is used as a seal for an expansion / contraction inner pipe that is not continuously applied with pressure.

  The present invention has been conceived to solve the leakage of the ground improvement material in the inner pipe, and the object thereof is to seal the outer peripheral surface of the tubular body by the seal member having the inner pipe material and packing. Accordingly, an object of the present invention is to provide a new ground improvement device telescopic excavation rod that can prevent leakage of the ground improvement material.

The present invention according to the above object is provided with an outer rod, an inner rod that is inserted into the outer rod so as to be extendable and fixed to the outer rod by a connecting pin, and an expansion and contraction that becomes a passage for a ground improvement material provided at the inner center of the inner and outer rod configure the drill rod by a freely inner tube, the inner tube, within the reach length of the inner rod upper end, a lower tube body outer rod side attached with the seal member of the cylinder to the upper end, the It consists of an upper tube with a stainless steel tube subjected to outer surface grinding of the rod side that is inserted into the lower tube through the seal member, the seal member, and the threaded end of the lower tube into one end of the cylindrical body A threaded portion to be screwed, an annular grease reservoir formed at the center of the inner surface excluding the threaded portion, an annular groove provided in multiple stages with an annular wear ring before and after the grease reservoir, and an annular groove dense outer peripheral surface of the interior and upper tube Is that formed by composed of a sealing rod seal packing ,,.

In the above configuration, the outer peripheral surface of the upper tubular body is tightly sealed by the rod seal packing that is built in multiple stages in the seal member, so that the sealing performance can be maintained with a small pressure and the durability of the seal is increased, so it can be used for a long time. Even so, leakage of ground improvement materials is prevented.
In addition, since the expansion and contraction of the upper tubular body is performed in a state where the outer periphery is supported by a cylindrical seal member, the friction with the lower tubular body is reduced, and the lubricity of the upper tubular body of the stainless steel pipe subjected to the outer surface polishing is reduced. Combined with the prevention of adhesion of the ground improvement material, an unreasonable burden is not applied to the packing, and the expansion and contraction operation can be performed smoothly.

  1 to 4 show the telescopic excavation rod of the present invention, wherein 1 is an outer rod, and 2 is an inner rod that is telescopically inserted into the outer rod 1. Reference numeral 3 denotes a telescopic inner pipe serving as a passage for the ground improvement material. The lower pipe 3a is provided through a lower pipe 3a provided in the center of the outer rod 1 and a seal member 4 attached to the upper end outside the lower pipe 3a. It consists of an upper tube 3b at the center of the inner rod 2 inserted into 3a. The upper tubular body 3b is made of stainless steel subjected to outer surface polishing. In some cases, the lower tube 3a may also be stainless steel.

  The outer rod 1 is composed of a cylindrical outer joint 12 provided at the upper end of the steel pipe 11 and having a hexagonal inner peripheral surface and an outer coupling 13 provided at the lower end of the steel pipe 11. The lower end of the tube 3a is attached. The lower tubular body 3a has a length such that the upper end reaches the inside of the inner rod 2 through the outer joint 12.

  The inner rod 2 has a steel pipe 21 having a smaller diameter than the steel pipe 11 of the outer rod 1, a hexagonal outer periphery covering the steel pipe 21, and a guide pipe 22 adapted to the outer joint 12, An upper rod 24 formed on the inner joint 23 that is hollow and has a hexagonal lower end connected to the upper end, and an outer peripheral surface provided on the lower ends of both pipes is provided on the upper end of the hexagonal inner joint 25 and the upper rod 24. The upper end of the upper tube 3b is connected to the inner coupling 26 so that a ground improvement material such as cement milk flows into the inner tube 3 from the inner coupling 26.

  The outer joint 12 and the inner joints 23 and 25 have laterally long semicircular grooves that form pin holes on both sides of the fitting surface, and are inserted from the side into the pin holes generated by the fitting of both joints. The connecting rod 27 has a normal structure in which the inner rod 2 is fixed to the outer rod 1. This pin hole is formed by the stoppers 28 and 29 provided on the lower end of the inner joint 23 and the rod side surface of the upper part of the inner joint 25 so that the positions of the semicircular grooves coincide with each other.

  As shown in FIG. 3, the seal member 4 has an inner diameter with a thickness obtained by adding an insertion clearance to the outer diameter of the upper tubular body 3b, and is a screw that is screwed into an end of the lower tubular body 3a in one end. Is given. An annular grease reservoir 42 is formed at the center of the inner surface excluding the threaded portion 41, and an annular wear ring 43 is sandwiched between the grease reservoir 42 and the outer circumferential surface of the upper tubular body 3b. Rod seal packings 44 are provided in multiple stages in an annular groove 45. This rod seal packing 44 is made of a rubber ring having a protrusion 44a on the packing contact surface, and can suppress the phenomenon that the seal portion escapes into the groove by the pressure applied to the lip of the protrusion 44a. And the durability of the seal is increased.

  In the telescopic excavation rod having the above configuration, as shown in FIG. 1, the inner rod 2 is inserted into the outer rod 1 until the stopper 29 on the side surface of the upper rod 24 contacts the upper surface of the outer joint 12 at the upper end of the outer rod. Thus, the excavating rod can be reduced, and the reduced state can be maintained by being fixed to the pin holes of the inner and outer joints 12 and 23 generated by the fitting by the connecting pin 27 inserted from the side. It is like that.

  Further, after the connecting pin 27 is pulled out to release the fixing, the inner rod 2 is moved from the inside of the outer rod 1 until the lower end of the inner rod 2 comes into contact with the lower surface of the outer joint 12 at the upper end of the outer rod, as shown in FIG. It can be pulled out and extended, and the extended state can be fixed and maintained in the pin holes of the inner and outer joints 12 and 23 generated by the fitting by the connecting pin 27 inserted from the side again.

  Corresponding to the expansion and contraction of the inner rod 2, the lower tube 3 a is moved in and out while sliding the rod seal packing 44 that is in close contact with the periphery of the tube while the upper tube 3 b is supported by the seal member 4 in the inner tube 3. Expand and contract. As a result, the inner tube 3 does not become an obstacle to the expansion and contraction of the inner rod 2, and the upper tube 3b that moves relative to the lower tube 2a is made of stainless steel that has been subjected to external polishing, so that the frictional resistance is low. Combined with the lubricity due to the grease (not shown) in the grease reservoir 42, the inner rod 2 can be expanded and contracted extremely smoothly.

  In the case of stainless steel subjected to external polishing, wear of the rod seal packing 44 is reduced and rust is not generated, so that it can be used for a longer period of time than in the case of conventional steel pipes. Further, since the cylindrical sealing member 4 is attached to the upper end of the lower tubular body 3a outside the upper tubular body 3b, the attaching portion is always located above the lower end opening of the upper tubular body 3b and is covered by the tubular wall. Since it is in a broken state, the cement milk of the ground improvement material flowing down the inner pipe 3 does not leak from the seal member 4.

  The telescopic excavation rod having the above configuration can be used in a single or multiple state. 5 and 6 show an embodiment when used as a quadruple telescopic excavation rod.

  As for the assembly, first, the above-mentioned four telescopic excavation rods are connected to the swivel 7 of the rotary drive device 6 accommodated and fixed individually in the quadrilateral support frame 5a by the inner coupling 26 at the upper end. To do. Further, a drilling head 10 (see FIG. 7) provided with a drilling stirring blade at the lower end of the outer rod 1 is fitted to the outer coupling 13 and connected integrally. Next, the support frames 5a are connected to each other in a single quadrilateral shape to form a support block 5 having a hanging bracket, and a guide plate 8 is attached to the support block 5. Further, when the pitch between the excavation rods is increased, as shown in FIG. 6, it is only necessary to dispose the spacer 5b between the support frame bodies 5a.

  As shown in FIG. 7, the four telescopic excavation rods are suspended by fitting a guide plate (not shown in the figure) on the guide 9a of the main unit 9 of the main unit using a crawler so as to be raised and lowered. It can be used by being suspended on the support block 5 by the wire 9b.

7 and 8 show the mixing and stirring process of a deep layer (for example, a depth of 25 to 35 m) by the telescopic excavation rod in the order of steps.
7A. First, the inner rod 2 is inserted into the outer rod 1 so that the upper stopper 29 comes into contact with the upper surface of the outer joint 12 of the outer rod 1 and is contracted. The connecting pin 27 causes the outer rod 1 and the inner rod 12 to be reduced. Is fixed (see FIG. 1).

  Next, the outer rod 1 and the excavation head 10 are rotated together with the inner rod 2 in the contracted state to penetrate the excavation rod into the soft ground. The penetration depth is set to such a depth that the connecting pin does not enter the ground and can be inserted and removed (hereinafter referred to as pin depth).

FIG. 8 (A) When the penetration reaches the pin depth, the rotation is stopped, the connecting pin is pulled out, and the fixation of the outer rod 1 and the inner rod 2 is released. Then, the inner rod 2 is pulled up to a position where the stopper 28 contacts the outer joint 12 of the outer rod 1 (see FIG. 2).
Fig. 8 (B) After the extension, the outer rod 1 and the inner rod 12 are fixed together with the connecting pin, and the cement milk is pumped to the inner pipe in the extended state, and the cement milk is discharged from the excavation head 10 to penetrate to the target depth. Continue to improve the ground.

  After improving to the target depth, it is pulled up to the pin depth in the stretched state as it is (see FIG. 8A). At the lifted position, the connecting pin is removed to release the fixation, the inner rod 2 is inserted into the outer rod 1 to be reduced, and the connection pin is again fixed to the outer rod 1. Thereafter, the outer rod 1 is pulled out from the ground to complete the construction.

  As described above, if mixing and agitating treatment by quadruple construction is performed using the telescopic excavation rod of the present invention, deep construction can be performed and the stability of the main body machine by head heavy is also increased. There is no need to use improved equipment, and it also contributes to the safety environment at the construction site.

It is a longitudinal cross-sectional view at the time of reduction of the expansion-contraction type excavation rod of the ground improvement apparatus concerning this invention. It is the longitudinal cross-sectional view at the time of expansion | extension similarly. It is a longitudinal cross-sectional view which expands and shows a principal part of this invention. FIG. 4 is a plan sectional view of a seal member portion in FIG. 3. It is a perspective view of the support block of quadruple excavation. It is a perspective view of the support block of quadruple excavation of other embodiment. It is explanatory drawing of the primary process of the mixing stirring process using the expansion | extension type | formula excavation rod of this invention. It is explanatory drawing of the secondary process of a mixing stirring process similarly.

Explanation of symbols

1 outer rod 2 inner rod 3 inner tube 3a lower tube 3b upper tube 4 seal member 12 outer joint 23 upper inner joint 24 upper rod 25 lower inner joint 27 connecting pin 41 threaded portion of seal member
42 grease reservoir
43 Wear Ring 44 Rod Seal Packing
44a packing protrusion
45 annular groove

Claims (1)

Drilling and outer rod, fitted telescopically into the outer rod, and the rod among fixed to the outer rod by a connecting pin, by a telescopic inner tube serving as a passage for soil improvement material provided inside the center of the inner and outer rod Make up the rod,
The inner tube, the length of the upper end reaches the inside of the inner rod, the lower tube body outer rod side attached with the seal member of the cylinder to the upper end, the rod-side inner inserted into the lower tube through the sealing member consist of an upper tube with a stainless steel tube subjected to outer surface grinding,
A screw part that engages with the screw at the end of the lower tubular body in one end of the cylindrical body, an annular grease reservoir formed at the center of the inner surface excluding the screw portion, and before and after the grease reservoir in an annular groove provided in multiple stages across the annular wear ring, the soil improvement apparatus characterized by being constituted by a rod seal packing which is in close contact seal an outer circumferential surface of the upper tube that interior to the annular groove Telescopic drill rod.

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