JP2010242343A - Ground investigation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground investigation apparatus which can measure a feeding force, striking force and rotation torque, applied to a rod driven by a rotary percussion drill. <P>SOLUTION: This soil investigation apparatus includes: a hydraulic sensor which is attached to each of a hydraulic actuator equipped with the rotary percussion drill and providing a rod with the feeding force, a hydraulically-driven hammer providing the striking force with the rod, and a hydraulic motor providing the rotation torque with the rod; a load cell which is attached to the lower portion of the rod so as to measure the feeding force, a striking force or rotation torque of the rod; a loading unit which is detachably and continuously attached to the lower end of the rod; and a control section which makes the rod driven in the continuously attached state of the loading unit, and which collects date on the measurement of hydraulic pressure, obtained from the hydraulic sensor, and data on the measurement of the feeding force, the striking force or the rotation torque, obtained from the load cell. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ground survey device, and more particularly, to a ground survey device capable of measuring a force applied to a rod driven by a rotary percussion drill by connecting a load unit simulating the ground to a rod.

  FIG. 6 shows a ground survey vehicle equipped with a conventional ground survey device. As shown in FIG. 6, the ground survey vehicle 1 has a rotary percussion (RPD) drill head 6 attached to an upper portion of a columnar guide 50, and the ground is drilled with a rod 4 to measure the strength of the ground. Extendable and retractable legs 3 are provided on the front and rear of the vehicle body, and the columnar guide 50 is erected on the installation base 20. (Patent Document 1)

  In such a ground investigation vehicle, the ground is drilled with a rotary percussion drill, hydraulic data at the time of drilling is collected, and substituted into an equation representing the converted N value to obtain an indicator of whether the ground is hard or soft. Yes. Among the converted N value variables, the feed force (kN), impact energy (kN · m), and rotational torque (kN · m) are the hydraulic pressure of the hydraulic motor that moves the drill head up and down, the rod head in the drill head The hydraulic pressure of the hammer and the hydraulic pressure of the hydraulic motor that rotates the rod in the drill head are measured with a hydraulic sensor and multiplied by the working area. The number of strikes (times / minute) is also detected by a hydraulic sensor, and the drilling speed (cm / minute) is detected by the rotation angle of a rotary encoder provided in a hydraulic motor that moves the drill head up and down.

  According to the example of the ground drilled with the rotary percussion drill (see FIG. 1 of Patent Document 1), the conversion value of the feeding force does not change greatly depending on the drilling depth and is about 1800 kgf (18 kN), The conversion value of the impact energy is a constant 50 kgf · m (500 N · m), and the conversion value of the rotational torque varies depending on the drilling depth, 100 kgf · m to 300 kgf · m (1 kN · m to 3 kN · m), etc. It has become. These values are calculated based on hydraulic pressure measurement data, and mechanical loss is not considered. Also, when the rotary percussion drill changes over time, the drilling force will be weaker than the original, but in that case the drilling force will be weak even if the hydraulic pressure is the same. Will be considered. That is, in the conventional ground investigation vehicle, there is no means for confirming how much drilling force is actually exerted by the hydraulic pressure of the rotary percussion drill. In addition, it is desirable that multiple ground survey vehicles are adjusted to have the same drilling force. However, in conventional ground survey vehicles, the hydraulic pressure can be adjusted, but the amount of feed force, striking energy, and rotation of the rod can be adjusted. There was no way to check if torque was applied.

JP-A-8-210075

  An object of the present invention is to provide a ground investigation device capable of accurately measuring the feeding force, striking force and rotational torque applied to a rod driven by a rotary percussion drill without actually drilling the ground. It is in.

  The ground survey device according to the present invention is equipped with a hydraulic sensor mounted on each of a hydraulic actuator that is mounted with a rotary percussion drill and that provides a feeding force to a rod, a hydraulically driven hammer that provides a striking force, and a hydraulic motor that provides a rotational torque. A load cell that is detachably attached to the lower portion of the rod and that measures a feeding force or striking force or rotational torque of the rod, a load unit that is detachably connected to the lower end of the rod, and the load unit is provided continuously. A control unit that drives the rod in a state of being collected and collects measurement data of hydraulic pressure obtained from the hydraulic sensor and measurement data of feed force, striking force, or rotational torque obtained from the load cell. .

  It is preferable that the controller is provided with a comparator that compares the value of the feeding force, the striking force, or the rotational torque generated by the hydraulic pressure with the reference feeding force, the striking force, or the rotational torque.

  It is preferable that the load unit includes a hydraulic cylinder mechanism for measuring a feeding force, a shock absorber for measuring a striking force, and a hydraulic pump mechanism for measuring a rotational torque.

  It is preferable that the hydraulic cylinder mechanism and the hydraulic pump mechanism are provided with a relief valve capable of adjusting a relief pressure.

  According to the ground survey device according to the present invention, a load unit for providing a reference load at the time of drilling operation is provided at the lower end of the rod, a load cell is attached to the lower portion of the rod, a hydraulic actuator for providing a driving force, and an impact force The hydraulic pressure and load cell measurement data were collected in combination with the hydraulic drive hammer and the hydraulic sensor installed in the hydraulic motor that gives the rotational force, so the hydraulic pressure and rod feed force and striking force prior to drilling the ground And the relationship between rotational torques. As a result, the feed force, impact energy, and rotational torque can be accurately converted from the hydraulic pressure measurement data measured during the actual drilling operation.

  In addition, since the control unit is provided with a comparator that compares whether the measurement value collected by the load cell has reached the standard, it is determined whether the hydraulic pressure for obtaining the predetermined feed force, impact energy, and rotational torque is appropriate. it can. By adjusting the hydraulic pressure of the hydraulic equipment in this way, the feed force, impact energy, and rotational torque can be made the same by a plurality of ground survey devices.

  Furthermore, since the load unit can be switched according to the measurement of the feeding force, the striking force, and the rotational torque, it can be quickly attached to and detached from the rod. The load unit of the feeding force consisting of a hydraulic cylinder mechanism increases the hydraulic pressure of the hydraulic cylinder to fix the rod, and measures the static load applied to the rod. It is possible to slide (length is limited by a hydraulic cylinder) and measure the dynamic load on the rod. The rotational torque load unit consisting of a hydraulic pump mechanism fixes the rod by increasing the hydraulic pressure of the hydraulic pump and measures the static load applied to the rod. It can also be rotated to measure the dynamic load on the rod.

  Furthermore, since the relief valve is provided in the hydraulic cylinder mechanism and the hydraulic motor mechanism, the relationship between the magnitude of the load (that is, the hardness of the ground) and the feed force or rotational torque can be grasped by adjusting the relief valve. Can do.

It is a basic lineblock diagram of the ground investigation device by the present invention. (Example 1) It is a graph which shows the relationship between each value (*) of the advance force, impact force, and rotational torque (*) measured with the load cell of a rod tip, and each value ((circle)) of reference advance force, impact force, and rotational torque . (Example 1) FIG. 1 is a ground surveying device configured to measure a feeding force applied to a rod. (Example 1) In FIG. 1, there is a ground investigation device configured to measure a striking force applied to a rod. (Example 1) FIG. 1 is a ground surveying device configured to measure rotational torque applied to a rod. (Example 1) It is a side view of the conventional ground investigation vehicle.

  Hereinafter, a ground investigation device according to the present invention will be described with reference to the drawings. In addition, the same code | symbol was used for the component of this invention mounted in the conventional ground investigation vehicle.

  FIG. 1 is a basic configuration diagram of a ground investigation device according to the present invention. The ground survey device 60 uses a rotary percussion drill to measure the feeding force, striking force, and rotational torque applied to the rod. As shown in FIG. 1, in the ground investigation device 60, a columnar guide 50 is erected on an installation base 20 (refer to FIG. 6 for the position) that can be lowered so as to contact the ground surface. At the top of the columnar guide 50, a hydraulic motor 14 (see FIG. 3) is provided as a hydraulic actuator for the feeding force. When the driving force of the hydraulic motor 14 is transmitted to the chain 10 and the chain 10 moves, the slide table 11 moves up and down depending on whether the hydraulic motor 14 rotates forward or backward. The hydraulic actuator for the feeding force is not limited to the hydraulic motor, and a hydraulic cylinder may be used. The drill head 6 is mounted on the slide table 11 and includes a hydraulic hammer mechanism 15 for impact (see FIG. 4) and a hydraulic motor 16 for rotation that rotates the rod 4 (see FIG. 5). Outputs of the hydraulic force sensor 7 for detecting the feeding force, the hydraulic force sensor 8 for detecting the impact force, and the hydraulic sensor 9 for detecting the rotational torque are sent to the control unit 30.

  As shown in FIG. 1, the load cell is detachably attached to the lower portion of the rod 4. The output of the load cell 5 is sent to the control unit 30. A load unit 12 is detachably connected to the lower end of the load cell 5. In a state where the load cell 5 and the load unit 12 are removed sideways, the rod 4 is pushed through the through-hole of the installation base 20 into the ground. The control unit 30 collects and records measurement data of the hydraulic sensors 7, 8, 9. Also, the output of the load cell 5 is collected and recorded. Further, as shown on the right side of FIG. 1, the relationship between the hydraulic pressure of the hydraulic sensor 7 and the driving force of the load cell 5, the relationship between the hydraulic pressure of the hydraulic sensor 8 and the impact force of the load cell 5, and the hydraulic pressure of the hydraulic sensor 9 and the load cell 5. Grasp the relationship with the rotational torque.

  When actually drilling the ground with the rod 4, the hydraulic pressure of the hydraulic sensors 7, 8, 9 is recorded by the control unit 30. The feed force, striking force, and rotational torque when calculating the converted N value can be obtained from the measured hydraulic pressure using the graph of FIG. In the converted N value, the impact energy is used, and the impact energy can be obtained by integrating the change in the impact force on the time axis.

  FIG. 2 shows the values of the feeding force, striking force and rotational torque (indicated by *) measured by the load cell at the end of the rod according to the present invention, and the values of the standard feeding force, striking force and rotational torque (◯). It is the graph which compared with. For comparison, as shown in the control unit 30 of FIG. 1, the reference value 13 of the feeding force, the striking force and the rotational torque and the feeding force, the striking force and the rotational torque obtained from the output value of the load cell 5 are compared with the comparator 13a. It is done by comparing with. As a result of the comparison, it is found that the feeding force, the striking force, and the rotational torque are excessive or insufficient. For example, if the feed force is lower than the expected value for the applied oil pressure, that is, the reference value, it can be calibrated to increase the oil pressure of the hydraulic device. If such adjustment is performed for each ground surveying device, the force applied to the rod during drilling can be set to be the same even if there is a difference in years of use among the ground surveying devices. In that case, the same result can be obtained regardless of the ground investigation device if the ground has the same hardness.

  FIG. 3 shows a ground investigation device 60a configured to measure the feeding force applied to the rod. Strain gauges 5a and 5b are attached inside the load cell 5 for detecting the feeding force. The strain gauges 5a and 5b are formed by bundling a plurality of gauge lines having a cross-sectional area A. If a strain gauge having a length L is stretched by ΔL in the longitudinal direction, the strain ε is ε = ΔL / L. At this time, the feeding force P for compressing the load cell 5 up and down can be calculated from P = E × (ΔL / L) × A. E is Young's modulus. On the other hand, ΔL / L is obtained by measuring a change in the resistance R of the strain gauge with a Wheatstone bridge circuit and using ΔR / R = k × ΔL / L. The strain gauge 5a is a compression type in which the longitudinal direction is provided vertically. The strain gauge 5b is a tension type in which the longitudinal direction is horizontally provided.

  As shown in FIG. 3, the load unit 12 includes a hydraulic cylinder mechanism including a cylinder 12d and a piston 12e, and the piston 12e is connected to a connecting rod 12g. Oil is sent from the control valve 12a to the upper chamber and the lower chamber of the cylinder 12d. Usually, the control valve 12a is formed with a crossing passage as shown on the right side, and oil is sent from the lower side of the check valve 12c to the lower chamber of the cylinder 12d by a pump (indicated by P). The piston 12e rises to a predetermined pressure. In this case, the piston 12e is pushed downward by the rod 4, but since there is a check valve, there is no place for oil to escape, and when the hydraulic pressure reaches a predetermined high pressure, the relief valve 12b is released and the oil is released to the oil tank 12f. Configured as follows. The relief valve 12b is a type that can be set to a predetermined relief pressure. If the relief pressure is set high, the load unit is compatible with hard ground, and if the relief pressure is set low, the load unit is compatible with soft ground. Measurement data corresponding to this can also be obtained.

  When the hydraulic motor 14 for feeding force is operated in a state where the lower chamber of the cylinder 12d is filled with oil and locked, the chain 10 is driven and the drill head 6 tries to descend, but the piston 12e is locked. Therefore, the rod 4 is distorted, and the feeding force can be measured by the load cell 5. If the hydraulic pressure of the cylinder 12d is increased and the piston 12e is fixed, the rod 4 is also fixed and does not descend, so that a static load can be measured. If the hydraulic pressure of the cylinder 12d is kept low and a strong feed force is applied to the rod 4, the piston 12e moves down in the cylinder 12d and the rod 4 slides, so the dynamic load applied to the rod 4 must be measured. Can do.

  FIG. 4 shows a ground investigation device 60b configured to measure the striking force applied to the rod. The load cell 5 is a load cell for detecting a striking force, and has the same measuring mechanism as the load cell for detecting a feeding force. The striking force is applied in a pulsed manner, and the feeding force is applied in levels, but the configuration of the measurement elements is the same. When measuring the impact force, the load unit 12 is switched to the shock absorber 12h. When the hitting hydraulic hammer mechanism 15 is actuated hydraulically, the hammer is pushed down and hits the top of the rod 4. Although the drill head 6 and the rod 4 are about to descend, the tip of the rod 4 is blocked by the shock absorber 12 h of the load unit 12, so that the rod 4 is distorted and the impact force can be measured by the load cell 5. The shock absorber 12h can be made of rubber as an example. The load received by the shock absorber 12h is received by the installation base 20 in contact with the ground surface. By changing the characteristics of the shock absorber 12h, it is possible to simulate the striking force from soft ground to hard ground.

  FIG. 5 shows a ground survey device 60c configured to measure the rotational torque applied to the rod. As shown in the drawing circle C1, strain gauges 5c and 5d are attached inside the load cell 5 for detecting rotational torque. The strain gauge 5c is a tension type in which the longitudinal direction is provided in the upper right diagonal direction. The strain gauge 5d is a compression type in which the longitudinal direction is provided in the upper left diagonal direction.

  When measuring the rotational torque, the load unit 12 is switched to the hydraulic pump 12i. As shown in a drawing circle C2, the hydraulic pump 12i has a partition blade 12k rotatably attached to the shaft of the connecting rod 12g to divide the interior into two oil chambers. In a state where one oil chamber is filled with oil, the partition blade 12k presses in the direction opposite to the rotation direction of the rod 4. Therefore, when the hydraulic motor 16 for rotating the drill head 6 is operated, the rod 4 is distorted along the circumferential direction, and the rotational torque can be measured by the load cell 5. If the hydraulic pressure of the hydraulic pump 12i is increased and the partition blade 12k is fixed, the rod 4 does not rotate, so that a static load can be measured. If the hydraulic pressure of the hydraulic pump 12i is kept low and a strong rotation is applied to the rod 4, the partition blade 12k rotates overcoming the hydraulic pressure, and the rod 4 also rotates, so the dynamic load applied to the rod 4 is measured. can do. When a rotational torque exceeding the set pressure of the relief valve 12b is generated, the relief valve 12b releases oil, so that the rod 4 rotates under a constant load.

  The load cell 5 and the load unit 12 are detachably provided at the position of the lower end of the rod 4. When actually excavating the ground, it is removed from the position of the lower end of the rod 4 so as not to disturb the insertion of the rod 4 into the ground.

  A load unit 12 including a hydraulic cylinder mechanism for measuring a feeding force, a shock absorber for measuring a striking force, and a hydraulic pump mechanism for measuring a rotational torque is installed in a switchable manner on a movable table. Thereby, the load unit 12 can be quickly attached and detached.

  INDUSTRIAL APPLICABILITY The present invention is suitable as a ground investigation device that can grasp the drilling force applied to the rod of a rotary percussion drill and can investigate the ground under the same conditions.

DESCRIPTION OF SYMBOLS 1 Ground investigation vehicle 2 Body frame 3 Leg 4 Rod 5 Load cell 5a, 5b Strain gauge in the load cell for detection of advancing force or impact force 5c, 5d Strain gauge in the load cell for detection of rotational torque 6 Drill head 7 Advance Hydraulic sensor for detecting force 8 Hydraulic sensor for detecting impact force 9 Hydraulic sensor for detecting rotational torque 10 Chain 11 Slide table 12 Load unit 12a Control valve 12b Relief valve 12c Check valve 12d Cylinder 12e Piston 12f Oil tank 12g Connecting rod 12h Shock absorber 12i Hydraulic pump 12k Partition blade 13 Reference value 13a Comparator 14 Hydraulic motor for feeding force 15 Hydraulic hammer mechanism for impact 15a Hammer 16 Hydraulic motor for rotation 20 Installation base 30 Control unit 50 Columnar guide 60 Ground survey Dress 60a Ground surveying device configured to measure the feeding force 60b Ground surveying device configured to measure the striking force 60c Ground surveying device configured to measure rotational torque

Claims (4)

A hydraulic sensor mounted on each of a hydraulic actuator that is equipped with a rotary percussion drill and that provides a feeding force to the rod, a hydraulically driven hammer that provides a striking force, and a hydraulic motor that provides rotational torque;
A load cell that is detachably attached to the lower portion of the rod, and that measures a feeding force or striking force or rotational torque of the rod;
A load unit detachably connected to the lower end of the rod;
A control unit that drives the rod in a state where the load unit is continuously provided, and collects measurement data of hydraulic pressure obtained from the hydraulic sensor and measurement data of feeding force, striking force, or rotational torque obtained from the load cell; The ground investigation device characterized by comprising.
The control unit is provided with a comparator that compares a value of a feed force, a striking force, or a rotational torque generated by hydraulic pressure with a reference power force, a striking force, or a rotational torque. Item 1. The ground survey device according to item 1.
The load unit includes a hydraulic cylinder mechanism for measuring a feeding force, a shock absorber for measuring a striking force, and a hydraulic pump mechanism for measuring a rotational torque, which are provided so as to be switchable. Ground survey equipment.
The ground investigation device according to claim 3, wherein the hydraulic cylinder mechanism and the hydraulic pump mechanism are provided with a relief valve capable of adjusting a relief pressure.

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