JPH0675039A - Ground investigation unit for excavating equipment - Google Patents

Abstract

PURPOSE:To allow accurate measurement of sound velocity or attenuation of sound pressure in the ground required for determination of the acoustic characteristics of soil by projecting a shaft into the ground to be dug in front of a shield partition and grounding a transmitter located at the tip thereof. CONSTITUTION:A cutter head 4 is provided on the front of an excavating equipment 1 having a center shaft 3 and a cutter 10 is provided on the front face thereof, i.e., a shield face plate 2. A shaft 5 is projected from the center shaft 3 into the ground to be dug in front of the shield face plate 2 by means of pushing, boring or drilling with a transmitter 7 being incorporated at the tip thereof. The tip transmitter 7 is connected through an acoustic communication with an oscillation sensor housed in a sensor housing. Since sound wave from the tip transmitter 7 can be received directly by means of a receiver, quality of soil to be dug can be measured accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for exploring the ground in front of an excavator.

[0002]

2. Description of the Related Art A wave transmitter and a wave receiver are installed in parallel on a shield face plate of an excavator, and sound waves are emitted from the wave transmitter toward obstacles such as buried objects in the ground and the boundary of the stratum. By reflecting, the signal received by the wave receiver was used as a signal waveform to search the ground in front of the excavator.

[0003]

However, in the above-mentioned conventional example, the position of the ground characteristic in front of the excavator could be searched by the signal waveform obtained by the sound wave being reflected by the obstacle or the stratum boundary in the ground. Since the corrugators were installed in parallel on the shield face plate, it was not possible to obtain accurate sound wave characteristics of the soil in front of the excavator. In order to know the exact position of the reflective surface (obstacle or stratum boundary), it is necessary to know the sound velocity in the soil correctly. Conventionally, the sound velocity of the ground between the two boring holes was investigated in advance. This is obtained by using the time difference of the direct wave that directly reaches the wave receiver from the wave transmitter. However, the method based on the preliminary survey is labor-intensive and it is difficult to deal with the case where the ground condition changes during the process.In addition, the method using the direct wave causes the ground in front of the transmitter / receiver to be disturbed as the excavation proceeds. And that there are multiple paths of sound waves that propagate directly through the machine body (metal) to which the transducer is attached,
Since it was difficult to separate the sound wave propagating in the soil and the sound wave propagating in the machine, any method had a problem in measuring the accurate sound velocity over the entire ground.

In addition, it is theoretically difficult in any of the above methods to measure the degree of attenuation of sound waves in the soil, which is necessary for knowing the search limit distance by the sound wave detection method.

Therefore, in the present invention, it is possible to measure the accurate sound wave velocity in the soil and the degree of attenuation of the sound pressure necessary to know the sound wave characteristics of the soil, and the direct wave propagating through the main body of the excavator can be measured. It is an object of the present invention to provide a ground exploration device for an excavator that can remove the influence.

[0006]

The present invention has been made in view of the above object, and its gist is a ground exploration device for an excavator, which includes a transmitter and a wave receiver attached to the excavator. The shield face plate of the excavator, together with the wave transmitter, or separately from the shield face plate, has a shaft projecting into the ground to be excavated from the front of the shield face plate, and a forward transmission having a transmission sensor at the tip of the shaft. It is a ground exploration device for an excavator, which is characterized by the installation of a wave implement.

Here, the shaft protruding from the shield face plate may be one which is provided by welding or the like from the beginning, but when measuring, it may be projected from the shield face plate by boring, a drill, or depending on the ground depending on the pressure. It is more convenient to use the one that does not interfere with the digging.
A known technique is used for displaying the wave form of the wave transmitter / receiver itself and the wave generation and wave reception signal of each device. Further, a plurality of wave receivers may be provided to make the sound wave reception from the wave transmitter and the destination wave transmitter more accurate.

[0008]

In the device of the present invention, the sound wave from the forward wave transmitter can be directly received by installing the forward wave transmitter in the soil in front of the excavator to be excavated. Therefore, the soil quality to be excavated from now can be accurately measured. In this case, the sound wave from the forward transmitter may be reflected by an obstacle in front and received by the receiver, but the reception time of each is different and does not affect the measurement of soil quality.

Since the receiving sensor is the same in both the measurement from the front transmitter and the measurement from the transmitter attached to the face plate, the received waveform is confused. Therefore, it is necessary to measure separately. In addition, depending on the nature of the ground,
It is also possible to perform measurement from the forward transmitter during excavation, improving work efficiency.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ground exploration device for an excavator according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory view showing the apparatus of the present invention in a longitudinal section, and FIG. 2 is an enlarged view of the forward transmitter in FIG. FIG. 3 is an enlarged explanatory view of a forward transmission device different from that of FIG. FIG. 4 is an enlarged explanatory view of the wave receiver of FIG. FIG. 5 is a waveform received by the conventional device obtained by the transducer on the shield face plate of the excavator, FIG. 6 is a waveform measured by a vibrometer, and FIG. 7 is a waveform obtained by subtracting the waveform of FIG. 6 from the waveform of FIG. It is a corrugated waveform.

1 to 4, there is a cutter head 4 at the front of the excavator 1, a center shaft 3 is provided at the center of the machine, and a cutter face 10 is provided on a shield face plate 2 which is the front face.

As in the prior art, the shield face plate 2 has a wave transmitter 6 for transmitting a sound wave and a wave receiver for receiving a signal returned by reflecting the transmitted sound wave on an obstacle such as rock in the earth and sand. 8 and 8 are arranged in sensor storage boxes 16 and 18, respectively.

On the other hand, the forward wave transmitter 7, which is one of the features of the device of the present invention, has a shaft 5 protruding from the center shaft 3 by a known method such as pressing, boring or drilling into the ground. It is placed and built into the tip. Further, a communication cable 9 for transmitting and transmitting sound waves is arranged on the destination wave transmitter 7 and is connected to a transmission sensor in the sensor storage box 17.

As shown in FIGS. 2 and 3, the details of the forward wave transmitter 7 are such that a receiving sensor is put in a sensor storage box arranged at the tip of the shaft 5 protruding from the shield face plate 2. Although this shaft 5 may be fixed to the shield face plate in a protruding state, it actually interferes with the excavation of the ground. Therefore, the screwed tip cone 12 shown in FIG. 3 is rotated to move inside the ground. It is preferable that the shaft 5 housed in the center shaft 3 is protruded while being connected to the shaft 5 by a screw 11 or the like after being propelled to be protruded or drilled in advance by boring or drilling.

Further, as for the details of the wave receiver 8, as shown in FIG. 4, a sensor storage box 16 is provided in the shield face plate 2, and the reception sensor 13 is fixed in the box 16 with bolts 14 and the front space thereof is oiled. It's full of liquid. In addition, the reception sensor 13
The sound waves from the communication cable 20 through the data converter 19
To the computer and display.
Further, in the vicinity of the bolt 14 to which the reception sensor 13 is fixed, a vibrometer 15 for catching vibration from the shield face plate 2 is fixed via a sensor storage box 16, and a signal from the vibrometer is converted to the theta converter described above. It is connected to 19 and is received in parallel with the signal from the reception sensor 13. 21 is a sound wave propagation medium as a liquid, and 22 is a sound wave insulator made of air.

The sensor storage box 16 is a vibration isolator made of seismic-proof metal so that noise such as driving sound of the excavator and working noise can be directly or completely eliminated, thereby exploring the ground. The accuracy of measurement can be improved. Further, the wave transmitter 6 and the wave receiver 8 have the same structure, although they have different transmission and reception sensors. Therefore, even if the wave transmitters / receivers 6 and 8 are replaced or a plurality of wave receivers are arranged. Can be measured.

A ground exploration method as another invention using the device of the present invention having the above-mentioned structure will be described below.

A sound wave is transmitted to the front of the excavator 1 by the wave transmitter 6. The transmitted sound wave is reflected by an obstacle such as an artificial structure buried object in the ground and returned by the wave receiver 8. At this time, from the wave transmitter 6 to the shield face plate 2
It also includes the sound waves that travel above. Although this unnecessary wave enters the reception sensor 13 together with the sound wave reflected from the obstacle, it is also measured by the vibrometer 15. The sound wave measured in this way shows a waveform including various other things such as a reflected wave from the front, a sound wave transmitted through the shield face plate, or a vibration of the excavator body (FIG. 5). Therefore, by subtracting the waveform (FIG. 6) measured by the vibrometer from such a waveform by calculation, an accurate measurement waveform (FIG. 1) excluding unnecessary vibrations as shown in FIG. 7 can be obtained. Therefore, more accurate ground exploration measurement determination can be obtained.

Next, the reflected wave returns to the wave receiver 8 in the wave receiver, and in the method using the direct wave, the ground in front of the wave receiver is disturbed by the excavation, and There are multiple paths of sound waves that directly propagate through the main body of the promoter (metal) to which the wave machine is attached, and it is difficult to separate the sound waves that propagate in the soil from the sound waves that propagate in the machine. Therefore, in the present invention, the tip cone 12 is pushed out while rotating the shaft 5 housed in the center shaft 3 described above forward.
The shaft is connected with a screw 11 depending on the pushed length.

When the tip of the shaft 5 reaches a predetermined position on the ground, a sound wave is transmitted from the forward transmitter 7. This sound wave
Since it reaches the receiver 8 directly, the transmitter 8 to the receiver 8
Up to the soil quality can be judged by the accurate sound wave velocity and the degree of attenuation of the transmitted sound wave. Further, the sound wave from the forward transmitter 7 is also received by the wave receiver 8 as a reflected wave from an obstacle in front, but since it is clearly delayed in time from the waveform of the directly received sound wave. There is no problem in measurement.

[0022]

According to the device of the present invention, the forward transmitter having the transmission sensor is installed at the tip of the shaft projecting into the ground to be excavated in front of the shield face plate of the excavator. Since sound waves can be received directly from the sensor to the wave receiver attached to the machine, it is possible to clearly distinguish between sound waves propagating in the soil and sound waves propagating in the machine.
Since the sound wave propagating in the soil is different in magnitude from the noise emitted from the excavator body, the sound wave can be clearly extracted. For this reason, the properties of the soil (acoustic characteristics) can be accurately measured by directly receiving the sound waves emitted from the transmission sensor attached to the tip of the shaft. It should be noted that the time required for soil measurement, the transmission frequency and the distance (constant) between transmission and reception, which are factors other than the sound pressure, other than the sound pressure are predetermined, and there is no problem in measurement.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a device of the present invention.

FIG. 2 is an enlarged view of a main part of the destination wave transmitter in FIG.

FIG. 3 is an enlarged view of an essential part showing another embodiment different from FIG.

FIG. 4 is an enlarged view of a main part of the wave receiver of FIG.

FIG. 5 is a waveform received by a wave receiver as a conventional device.

FIG. 6 is a waveform measured by the vibrometer of FIG.

FIG. 7 is a waveform obtained by subtracting FIGS. 5 to 6 by calculation.

[Explanation of symbols]

 1 excavator 2 shield face plate 5 shaft 6 wave transmitter 7 forward wave transmitter 8 wave receiver

Front page continuation (72) Inventor Tatsuji Osamu 2-5-8 Kitaoaoyama, Minato-ku, Tokyo In-house (72) Inventor Masao Kinoshita 5-3-28 Nishikujo, Konohana-ku, Osaka, Japan Hitachi Zosen Incorporated (72) Inventor Toshiaki Morii 5-3-8 Nishi-Kujo, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd.

Claims (1)

[Claims] 1. A ground exploration device for an excavator, which comprises a transmitter and a wave receiver attached to the excavator, wherein a shield face plate of the excavator is provided with or without the transmitter. A ground exploration device for an excavator, characterized in that a shaft is projected into the ground to be excavated from the front of the face plate, and a forward transmitter having a transmission sensor is installed at the tip of the shaft.