JP2005105582A - Soil investigating method and vibration damper used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent having influence of noises on a worker as a low noise, by carrying a vibration damper in a soil investigating site by passing through a narrow space of a degree capable of passing a person. <P>SOLUTION: An air damper 20 is equipped on both sides of a drive head 2, and a spindle 21 is vertically movably arranged to the drive head 2 in the center of the drive head 2, to transmit rotation of the drive head. The spindle 21 is installed in a vibrator 1, and vibration generated by the vibrator 1 is directly transmitted to the spindle 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a soil survey method in a place where the soil survey or excavation site is narrow or the access path to the site is narrow and it is difficult to carry in the soil survey machine, and a vibrator-type hand-held soil survey used in the method The present invention relates to a vibration damping device that cushions vibrations of a machine and a vibrator.

  If the place where the soil is surveyed is small, a large survey machine cannot be carried in. Conventionally, a hand-held vibration type soil survey machine with a core sampling tool attached to an engine breaker or the like using a gasoline engine as a drive source shown in FIG. 10 is used. I was dealing with it. However, this vibration type soil surveying machine is supposed to be operated by human power at all times, the excavation capacity is small and efficient excavation work cannot be performed, and the vibration generation method uses a gasoline engine as the drive source, There was a problem that the noise was loud.

In addition, there is a drill (product name Neko drill) equipped with an electric motor as a drive source on a frame having wheels, but the device is simply downsized, the device is disassembled, and the drive unit is separated to be a hand-held device. There was no idea of excavating the soil, and it was not possible to conduct an efficient soil survey by incorporating the drive source into a frame with a feed device.
It was uneconomical to prepare these small soil excavators separately.
JP 2001-207435 A

  In recent years, there has been a growing interest in environmental issues and the continuous detection of pollutants from the site of factories, and investigations have become essential as regulations on contaminated soil have been tightened. Against this background, the investigation of pollutants in soil, which has been conducted in the former site of the factory, has come to be carried out in the factory in operation.

  There is a problem that the soil inspection machine that was not a big problem in the survey of vacant lots where there is no structure such as factory ruins can not be carried in smoothly due to the existence of the structure due to the presence of the structure. I got up. In addition, because the soil survey is carried out in the factory premises that are in operation, the conventional hand-held soil survey machine has a problem that the sound generated is noisy for working employees and adversely affects the performance of work. .

For this reason, it is possible to move in a narrow space that allows humans to pass through, and there is an increasing need for conducting a soil survey with low noise so as not to affect the noise of humans during work.
In order to meet such needs, the present invention provides a soil survey method that can be disassembled and operated by hand as necessary.

The vibrator can be removed from the soil surveying machine body, allowing it to pass through a narrow space, allowing the soil surveying machine to be carried into a narrow space, and attaching a vibration buffering device that enables hand-held operation to form a handheld soil surveying machine. In addition to being able to be used, the soil survey can be performed more efficiently than a conventional hand-held soil survey machine.
The vibrator is driven by a hydraulic motor, and does not emit noise like conventional hand-held soil survey machines, and is low in noise, so that even a factory in operation can be surveyed without affecting normal operations. Became.

  On the other hand, in places where there is room in the soil survey site, the vibrator should be attached to the soil survey machine body and have a frame and feed device to efficiently perform soil survey work and reduce the burden on the operator Can do.

  As shown in FIG. 1, the soil investigation machine 10 can apply vibration and rotation to the boring rod 3, and the drive head 2 is attached to the frame 6 or the mast so as to be movable up and down. Air dampers 20 are provided on both sides of the drive head 2 to buffer the vibration of the vibrator 1 from being transmitted to the frame 6.

As shown in FIGS. 2 and 3, an eccentric weight type vibrator 1 driven by a hydraulic motor M <b> 2 is fixed to the upper portion of the drive head 2 with a bolt 11.
A spindle 21 is attached to the drive head 2, and the rotation of the hydraulic motor M1 is transmitted via a speed reducer. Further, the vibration of the vibrator 1 is transmitted to the spindle 21 via the drive head 2.

The rotation and vertical vibrations transmitted to the spindle 21 are transmitted to the boring rod 3 connected to the tip of the spindle 21 and excavated into the ground, and a soil sample is taken into a sampler (not shown) attached to the tip of the boring rod 3. It is.
Further, since the drive head 2 can be moved in the vertical direction along the frame 6 by a feed cylinder provided on the back surface of the frame 6, a downward pressing force can be applied to the boring rod 3.
If there is a large space to the soil survey site, the soil survey machine 10 including the frame 6 is carried directly to the survey site without disassembly, and the sampler is efficiently put into the ground by adding rotation and vibration to the boring rod. Excavate and perform soil sampling work.

  On the other hand, when a narrow passage exists in the middle of the soil survey site and the soil survey machine 10 cannot be carried into the survey site, the bolt 11 for fixing the vibrator 1 is loosened and the pin 13 of the air damper 20 is removed. Remove the vibrator 1 from the main body.

The vibrator 1 removed from the drive head 2 is attached to the vibration damper 4 shown in FIG. 4 so that the operator can hold the vibrator 1 and perform soil sampling work.
The vibrator 1 is capable of generating vibrations up to about 60 Hz, and holding it directly by an operator may cause health problems due to vibration, so it is necessary to prevent the vibration from being transmitted to the operator. In other words, it is necessary to attach a vibration damper (damper) for buffering vibration.

The vibration damper 4 will be described with reference to FIGS.
Although the spring body is displayed as a coil spring, the spring body is not limited to the coil spring, and any spring body may be used. The band-shaped rubber can be procured at a low cost and is light in weight so that it can be easily transported and is preferable as a spring body for a shock absorber of a small hand-held soil surveying machine.

As shown in FIG. 4, in the vibration damper 4, a circular outer frame 40 and an inner frame 41 are concentrically arranged, and both frames are connected by a belt-like rubber 42 that is a spring body. The outer frame 40 can be moved up and down by the elasticity of the rubber 42.
The inner frame 41 is provided with a fixing base 43 for fixing the vibrator 1, and the vibrator 1 that has been removed and carried in can be fixed with a bolt. This bolt uses the thing which fixed the vibrator 1 and the drive head 2 in the soil investigation machine 10. FIG.

In order to make it a lightweight and simple type that can be operated by a hand by an operator, the boring rod is not rotated, but the boring rod is dug into the ground only by the vibration of the vibrator 1 to sample the soil.
6 and 7 show a state in which the rubber of the spring body is not attached. FIG. 6 shows a state in which only the outer frame 40 is provided, and FIG. 7 shows a state in which the inner frame 41 is disposed in the outer frame 40.
The handle 12 for the operator to hold the soil survey device is formed by bending the pipe into a quadrangle and is connected to the outer frame 40 by a connecting member 44. Since it is rectangular, the worker can hold the handle 12 from four directions.
As shown in FIG. 7, the fixing base 43 to which the vibrator 1 is attached is attached to an inner stay 45 extending in the center direction from the inner frame 41, and moves up and down with the inner frame 41 relative to the outer frame 40.

  Further, a centering guide 47 is supported at the center of the outer frame 40 by an outer stay 46 extending in the center direction. The centering guide 47 has a hollow portion, and extends from a drive head connected to the vibrator 1 to the hollow portion. A drive rod is inserted, and a boring rod is connected to the drive rod. A rubber stopper 5 is provided outside the centering guide 47 to limit the drive head ascending. In a normal state, the stopper 5 hits the inner stay 45 to prevent the drive head from rising.

FIG. 8 shows a state in which the vibrator 1 and the vibration damper 4 are assembled by the worker, the boring rod 3 with a sampler attached to the tip is connected to the drive rod, and the ground is excavated for collecting a soil sample. Show.
The worker holds the handle 12 and applies a force for pulling it down and operates the vibrator 1 to push the bit at the tip of the boring rod against the ground for excavation. The force with which the operator pulls down the handle 12 is the force with which the outer frame 40 is directly pulled down. A centering guide 47 having a drive rod insertion portion is attached to the inner side of the outer frame 40 via an outer stay 46, and the centering guide 47 can move up and down with respect to the drive rod 30.

When an operator applies a downward force to the handle 12, the force is transmitted to the outer frame 40 via the connecting member 44, and is applied to the inner frame 41 via a belt-shaped rubber 42 that connects the outer frame 40 and the inner frame 41. Further, the signal is transmitted to the inner stay 45 and the drive rod 30 is pushed down. When the tip of the boring rod 3 connected to the drive rod 30 is pressed against the ground and the reaction force becomes larger than the elastic force of the rubber 42 of the vibration damping device 4, the rubber 42 extends and the outer frame 40 becomes the inner frame 41. Is lowered against.
As the outer frame 40 descends, the centering guide 47 connected to the outer stay 46 is pulled down and separated from the rubber upper stopper 5.

  When the operator operates the vibrator 1 with a pressing force applied to the handle 12, the generated vibration is transmitted to the boring rod 3 through the drive rod 30 and excavated, and is supported by vertical vibration and human power support. A sampler attached to the boring rod 3 is dug into the ground to sample a soil sample. A part of the vibration is transmitted to the handle 12 through the outer frame 40, but this vibration is absorbed by the vibration damper 4, and the vibration is hardly transmitted to the worker holding the handle 12.

The principle of the buffer action of the vibration damper 4 will be described below with reference to FIG. 9 showing a dynamic model of the vibration damper of the present invention.
The natural frequency ω of a system composed of a spring having a spring coefficient k and a mass m can be expressed by the following equation.
ω = (k / m) ^1/2
k: Spring coefficient m: Mass to vibrate From the above equation, it can be seen that the natural frequency ω can be kept low by reducing the spring coefficient k.

A in the central portion indicates an inner portion including an object (vibrator) for suppressing vibration, B indicates an outer portion, and both are connected by a plurality (n pieces) of springs having a length L with a spring coefficient Ks. . In a state where the inner portion A receives a force and is displaced by S in the vertical direction, the force Fs acting on the spring is expressed as follows:
Fs = Ks · ΔL (1)
Geometrically ΔL is ΔL = L / cos θ−L
= L / cos θ · (1-cos θ) (2)
Further, if the spring coefficient of the vibration damper as a whole is Kt and the number of springs is n, and the vertical component of the force Fs in the axial direction of the spring is Fv,
Kt = n · Fv / S (3)
Fv = Fs · sin θ (4)
Geometrically the vertical displacement S is S = L · tan θ (5)
From the above, when the expressions (4) and (5) are substituted into the expression (3) and further the expressions (1) and (2) are substituted, the expression (3) becomes as follows.
Kt = n · Ks · (1−cos θ) (6)

  From Equation (6), the second term of Equation (6) can be brought close to 0 by reducing the angle θ. Therefore, the overall spring coefficient Kt can be kept small, the natural frequency of the whole apparatus can be kept low, and the effect as a vibration damper can be exhibited.

As described above, the vibrator can be detached from the main body, and the handle and the vibration damping device are additionally attached, so that the vibrator can be carried into the site by human power even in a passage that allows humans to pass through. It is possible to do soil sampling by human power at the survey site.
In addition, since the vibration drive source of the vibrator is a hydraulic motor, the noise is lower than that of a conventional hand-held vibration-type soil sampler, and the influence of noise on workers is low. It was possible.
If there is room in the soil survey site, the vibrator that has been removed and carried in can be attached to the main body and operated as a soil survey machine with a frame and feed device, enabling efficient soil survey work. The burden can be reduced.

The front view of the soil investigation machine which has a frame. The detailed front view of the attachment part of a vibrator and a drive head. The detailed side view of the attachment part of a vibrator and a drive head. The top view of the principal part of a vibration damper. The front view of the state which attached the vibrator to the vibration damper. The top view of an outer frame. The top view of the state which has arrange | positioned the inner frame in an outer frame. Explanatory drawing of the use state of a hand-held soil survey machine. Mechanical model of the shock absorber. The front view of the conventional handheld soil investigation machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibrator 11 Bolt 12 Handle 2 Drive head 20 Air damper 21 Spindle 3 Boring rod 30 Drive rod 4 Vibration damping device 40 Outer frame 41 Inner frame 42 Rubber (spring body)
6 frames

Claims (3)

A soil survey method in which a vibrator of a soil surveying machine in which a vibrator is attached to the frame so as to be movable up and down is removed, and a vibration buffering device and a handle are attached to the vibrator to form a hand-held soil surveying machine. In the first aspect of the present invention, the vibration damper has a fixed base disposed in the outer frame, the outer frame and the fixed base are connected by a plurality of radially arranged spring bodies, and the fixed base is displaceable with respect to the outer frame. A soil survey method that samples the soil manually. A vibration damping device in which a fixed base is disposed in an outer frame, the outer frame and the fixed base are connected by a plurality of spring bodies, and the fixed base is displaceable with respect to the outer frame.

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