Excavator

Abstract

To prevent a drilling head and a rod from falling into a drilling hole due to operator's erroneous operation.SOLUTION: A drilling machine that drills the ground with a drilling head while applying rotational force and vertical vibration to a rod having the drilling head connected to its tip comprises: a clamp device for gripping the rod; a clamp control unit for controlling the operation of the clamp device; an elevating device for elevating the rod; and movement detection means for detecting movement of the elevating device. The clamp control unit is configured to maintain the gripping state of the rod when an upward movement of the elevating device is detected based on the movement detection means while the rod is gripped by the clamp device.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an excavator for excavating the ground.

Background Art

[0002] For example, Patent Document 1 discloses a drilling and mixing device used when constructing soil-cement columns in the ground. The drilling and mixing device includes a rod with a drilling bit connected to its tip, and while a steel pipe is added to this rod, the drilling bit is rotationally pressed into the ground. At the same time, by discharging cement milk from the tip of the drilling bit, the ground is drilled while constructing a soil-cement column in the drilled hole.

[0003] Specifically, as shown in FIG. 6, a rod 150 is connected to a rotating means 130 that slides along a guiding member 110 provided in the drilling and mixing device 100 via a swivel joint 140, and a drilling bit 二百 is connected to the tip of the rod 150. Then, the rod 150 is rotated via the rotating means 130 and lowered along the guiding member 110 to be pushed into the ground, and the ground is drilled and mixed with the drilling bit 200 provided at the tip of the rod 150.

[0004] When the rotating means 130 reaches the lower end of the guiding member 110, the operation of the rotating means 130 is temporarily stopped, and the rod 150 is gripped by a chuck mechanism 120 provided at the lower end of the guiding member 110. Next, the connection state between the swivel joint 140 and the rod 150 is released, and the rotating means 130 is slid upward along the guiding member 110. After that, a steel pipe 160 for addition is placed between the rod 150 and the swivel joint 140, its upper end is connected to the swivel joint 140, and its lower end is connected to the upper end of the rod 150.

[0005] It should be noted that there seems to be an error in the original text where "掘削ビット200" is written as "二百" in the translation of line 16. It should be corrected to "200" in the English translation.In this state, after releasing the grip of the rod 150 by the chuck mechanism 120, the rod 150 is again rotated via the rotating means 130 and lowered along the guide member 110, pushing the drilling bit 200 into the ground again. In this way, by drilling and stirring while sequentially adding extension steel pipes, a soil cement column is created in the ground to a predetermined depth. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-252349 [Overview of the project] [Problems that the invention aims to solve]

[0007] According to Patent Document 1, it is possible to construct a soil-cement column P of a desired depth by sequentially extending steel pipes 160, even in low-headroom environments. However, as the length of the soil-cement column P to be constructed increases, the number of times steel pipes 160 need to be extended increases, which makes it easy for workers to make mistakes.

[0008] Specifically, errors are likely to occur, such as releasing the chuck mechanism 120 even though the rod 150 is being held solely by the chuck mechanism 120. If such an error occurs, the rod 150 will fall into the borehole filled with drilling mud along with the drilling bit 200. As a result, it becomes difficult to visually confirm the fallen drilling bit 200 and rod 150, making it difficult to lift them up by rigging. Even if rigging is possible, the retrieval process is extremely time-consuming, as the drilling bit 200 may come into contact with the borehole wall.

[0009] Furthermore, if the drilling bits 200 and rods 150 cannot be recovered, not only will they have to be left buried permanently, but the resulting holes cannot be used to construct the soil-cement columns P, requiring design changes. These issues tend to lead to delays in the construction period and increased costs, and have a significant impact on the project, so measures to reduce worker errors were desired.

[0010] The present invention has been made in view of the above problems, and its main purpose is to prevent the drilling head and rod from falling into the drilled hole. [Means for solving the problem]

[0011] To achieve this objective, the excavator of the present invention is It consists of multiple rod bodies connected via a joint structure, An excavator that excavates the ground with a drilling head while applying rotational force and vertical vibration to a rod to which a drilling head is connected at the tip, comprising: a clamping device for gripping the rod; a clamping control unit for controlling the operation of the clamping device; and a lifting device for raising and lowering the rod. An excavator control unit that controls the operation of the lifting device, The clamp control unit comprises a movement detection means for detecting the movement of the lifting device, Before performing the opening operation of the clamp device, the lifting device is raised via the excavator control unit. When the upward movement of the lifting device is detected based on the movement detection means, It is determined that the rod is being held only by the clamping device, The device is characterized by being configured to maintain the gripping state of the rod.

[0013] According to the excavator of the present invention described above, even if the clamp control unit receives an operation signal to release the grip on the rod, it maintains the grip on the rod by the clamp device as long as it detects the upward movement of the lifting device based on the movement detection means. Therefore, even if an operation signal to release the grip on the rod is sent due to operator error or unforeseen circumstances while the rod is gripped only by the clamp device, the phenomenon of the rod and drilling head falling into the borehole can be suppressed. This makes it possible to improve the workability of drilling operations. [Effects of the Invention]

[0014] According to the present invention, even if an operation signal is sent to release the grip on the rod due to operator error or unforeseen circumstances while the rod is gripped only by the clamping device, it is possible to prevent the drilling head and rod from falling into the drilled hole. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows a schematic diagram of an excavator according to an embodiment of the present invention. [Figure 2] This figure (Part 1) shows the procedure for drilling underground using an excavator according to an embodiment of the present invention. [Figure 3] This figure (part 2) shows the procedure for drilling underground using an excavator according to an embodiment of the present invention. [Figure 4] This figure shows a clamp control unit that controls the operation of a clamping device in an embodiment of the present invention. [Figure 5] This diagram shows the flow when an operation signal to release the grip of the rod is transmitted to the clamp control unit in an embodiment of the present invention. [Figure 6] This diagram shows how to drill into the ground using a conventional drilling and stirring device. [Modes for carrying out the invention]

[0016] The excavator of the present invention will be described in detail with reference to Figures 1 to 5. In this embodiment, the case of constructing a borehole is given as an example, but the excavator can also construct soil-cement columns.

[0017] <<<Excavator>>> As shown in Figure 1, the excavator 1 used to excavate the target ground comprises a crawler-type vehicle 2, an upper rotating body 3 mounted on the crawler-type vehicle 2, and a leader 4 that is supported to be able to be raised and lowered.

[0018] The leader 4 includes a guide 41 extending vertically on its front side in the standing posture, and a lifting device 42 is provided to move up and down along the guide 41. On the back side, two telescopic devices 43 and 44 are provided, and through these, the leader 4 and the upper swing body 3 are connected. By the telescopic operation of the telescopic devices 43 and 44, each posture of the leader 4 in the upright and reclined positions can be made freely adjustable.

[0019] Also, at the lower end of the leader 4, a clamping device 45 for gripping the rod 20 is provided. The clamping device 45 includes a through-hole through which the rod 20 passes, and a clamp body 451 that can protrude and retract toward this through-hole. By protruding the clamp body 451 so as to close the through-hole, the rod 20 is gripped. On the other hand, by housing the clamp body 451 so as to open the through-hole, the gripping of the rod 20 is released.

[0020] Hereinafter, the operation and state of gripping the rod 20 are referred to as the closing operation and the closed state, and the operation and state of releasing are referred to as the opening operation and the open state. For the clamp body 451, for example, a hydraulic jack or the like can be adopted, but it is not limited thereto, and any device may be adopted as long as it has a configuration capable of gripping the rod 20. Also, the clamping device 45 does not necessarily have to be mounted on the leader 4.

[0021] The excavator 1 further includes a vibration device 9 mounted on the lifting device 42, a rotating device 8 connected to the lower part of the vibration device 9, and a drive shaft 7 that penetrates the rotating device 8 and has its proximal end connected to the vibration device 9. Also, the excavator 1 includes a rod 二十 that is connected to the distal end of the drive shaft 7, and an excavation head 10 that is connected to the distal end of the rod 二十.

[0022] The vibration device 9 is a device that generates a vertical vibration force by rotating an eccentric weight, and moves along the guide 41 via the lifting device 42, so that it moves in the lifting direction when the leader 4 is upright. Note that any vibration device 9 may be adopted as long as it can generate a vibration force capable of transmitting a vibration including a vertical component to the drive shaft 7.

[0023] The rotating device 8 is installed on the lifting device 42 and connected to the vibration generator 9, and moves together with the vibration generator 9 along the upright leader 4. Inside it is a drive shaft locking part (not shown) which locks the circumferential surface of the drive shaft 7 and applies a rotational force in the forward or reverse direction around the shaft.

[0024] The drive shaft 7 is a single pipe with a hollow section, and a swivel joint 6 is attached in the middle to which a fluid supply pipe 5, such as a cement grout supply pipe or a stabilizing fluid supply pipe, is connected. This allows fluids such as cement grout and stabilizing fluid S supplied from the fluid supply pipe 5 to be supplied to the rod 20 via the drive shaft 7 through the swivel joint 6. Figure 1 shows an example where stabilizing fluid S is supplied.

[0025] ≪≪Rod and drilling head≫≫ The rod 20 has its base end connected to the drive shaft 7 via a joint structure 50, and its tip end connected to the drilling head 10 via a joint structure 50. The rod consists of a rod body 30 and a joint structure 50 that connects the rod body 30 in the axial direction.

[0026] As shown in Figure 3(b), the rod body 30 comprises a pipe 31, a convex joint 32 provided at one end, and a concave joint 33 provided at the other end that engages with the convex joint 32. The joint structure 50, as shown in Figure 1, is composed of a connecting pin 34 that penetrates both the convex joint 32 of the lower rod body 30 and the concave joint 33 of the upper rod body 30, with the concave joint 33 of the upper rod body 30 engaged with the convex joint 32 of the lower rod body 30.

[0027] The above-described joint structure 50 is used not only for connecting the rod bodies 30 to each other, but also for connecting the rod 20 to the drive shaft 7 and the rod 20 to the drilling head 10, as shown in Figure 1.

[0028] The drilling head 10 is connected to the tip of the rod 20 and comprises a shaft portion 11 made of a single pipe with a hollow section, a drilling blade body 13 attached to the tip of the shaft portion 11 so as to extend laterally, and a bit 14 attached to the drilling blade body 13. In addition, a plurality of stirring blades 12 extending radially are installed on the shaft portion 11 at a position spaced above the drilling blade body 13, and a tip bit 15 and a fluid discharge port 16 are provided at the tip of the shaft portion 11.

[0029] The bits 14 and 15 have a shape that allows them to excavate the ground regardless of whether the drilling head 10 rotates in the forward or reverse direction around the rod axis. The fluid discharge port 16 discharges the fluid supplied from the fluid supply pipe 5 to the shaft portion 11 via the swivel joint 6, drive shaft 7, and rod 20 toward the ground. In this embodiment, since a borehole H is being excavated, the fluid discharged from the fluid supply pipe 5 is a stabilizing fluid S. However, if cement grout is used as the fluid, it is also possible to construct a soil-cement column instead of a borehole H.

[0030] Furthermore, the stirring blades 12 provided on the drilling head 10 are used when constructing a soil-cement column as described above, by discharging cement grout from the fluid discharge port 16 while excavating the ground, or when, after constructing a borehole H, a cement-based solidifying agent is supplied to the borehole H and mixed with the stabilizing liquid.

[0031] ≪≪Procedure for underground drilling using an excavator≫≫ The procedure for drilling a borehole H in the ground using the excavator 1 having the above configuration will be explained with reference to Figures 2 and 3.

[0032] As shown in Figure 2(a), the excavator 1 is set up at the planned location for construction of the borehole H, and ground drilling is started. Ground drilling is performed by transmitting a forward rotational force from the rotating device 8 and vertical vibrations from the vibration generator 9 from the drive shaft 7 to the drilling head 10 via the rod 20. At this time, the clamp body 451 of the clamping device 45 is in the open state.

[0033] During drilling, stabilizing fluid S is supplied from the fluid supply pipe 5 to the drive shaft 7 via the swivel joint 6, and then discharged into the borehole H from the fluid discharge port 16 via the rod 20 and the shaft portion 11 of the drilling head 10. The stabilizing fluid S filling the borehole H is discharged using a vacuum hose V inserted into the borehole.

[0034] As shown in Figure 2(b), as excavation progresses, the excavation head 10 descends along with the lifting device 42, and when the joint structure 50 of the rod 20 approaches the vicinity of the upper end of the clamping device 45, the operation of the rotating device 8 and the vibration exciter 9 is temporarily stopped. After this, the process of adding a new rod body 30 to the rod 20 begins.

[0035] The extension work begins by switching the clamp body 451 of the clamping device 45 to the closed position, gripping the rod 20 which is inserted into the borehole H. Next, the connecting pin 34 of the joint structure 50 is removed, releasing the connection between the convex joint 32 and the concave joint 33. After this, the lifting device 42 is driven, and the lifting device 42, on which the rotating device 8 and vibration generator 9 are mounted, is raised along the guide 41.

[0036] As shown in Figure 3(a), a working space is formed between the upper end of the rod 20 gripped by the clamping device 45 and the drive shaft 7 which rises along with the rise of the lifting device 42. A new rod body 30 is added using this working space. Specifically, as shown in Figure 3(b), the convex joint 32 of the rod body 30 gripped by the clamping device 45 is fitted with the concave joint 33 of the newly added rod body 30, and a connecting pin 34 is attached to them to form a joint structure 50, as shown in Figure 1.

[0037] Next, the drive shaft 7 is lowered together with the lifting device 42, and the concave joint 33 of the drive shaft 7 is fitted with the convex joint 32 of the newly added rod body 30. In the same manner, the connecting pin 34 is attached to form the joint structure 50. As a result, the length of the rod 20 is extended and it is connected to the drive shaft 7. At this time, the clamp body 451 of the clamping device 45 remains in the closed state.

[0038] Next, the clamp body 451 of the clamping device 45 is switched to the open position, and the rod 20 is suspended via the drive shaft 7 as shown in Figure 1. After these operations are completed, the rotating device 8 and the vibration device 9 are activated, and drilling operations by the drilling head 10 are resumed. By repeating the operations of drilling the ground and extending the rod body 30 in this manner, a borehole H with the desired depth is constructed in the ground.

[0039] ≪≪Error prevention function≫≫ Incidentally, during the extension work described above, as shown in Figures 3(a) and 3(b), there is a period of time when the rod 20 inserted into the borehole H is held only by the clamp body 451 of the clamping device 45. If the clamp body 451 opens during this period, there is a risk that the rod 20 will fall into the borehole H together with the drilling head 10.

[0040] Therefore, the excavator 1 is equipped with a function to prevent accidental operation by the worker or unforeseen circumstances, in order to avoid the situation in which the rod 20 falls into the borehole H together with the drilling head 10. The details of the configuration related to the operation of the excavator 1, including the function to prevent accidental operation, will be explained below with reference to Figure 4.

[0041] <Configuration related to the operation of excavator 1> As shown in Figure 4, the excavator 1 is equipped with a clamp control panel 17 and a clamp control unit 18 operated by a worker, and an excavator control panel 191 and an excavator control unit 192.

[0042] The excavator control panel 191 is a control panel that transmits operation signals to control the operation of the vibration generator 9, the rotating device 8, and the lifting device 42. The excavator control unit 192 receives these operation signals and controls the operation of the vibration generator 9, the rotating device 8, and the lifting device 42.

[0043] The clamp control panel 17 is a control panel that transmits operation signals to control the opening and closing operation of the clamp body 451, and is equipped with, for example, an open button and a close button that can be operated by a worker. The clamp control unit 18 receives the operation signals and controls the opening and closing operation of the clamp body 451 based on them.

[0044] ≪Clamp Control Unit 18≫ The configuration and operation of the clamp control unit 18 will be described in detail below with reference to Figure 4.

[0045] As shown in Figure 4, the clamp control unit 18 comprises an input unit 181, a calculation control unit 182, and an output unit 183. The input unit 181 and the output unit 183 exchange signals with the clamp operation panel 17, the display 171 on the clamp operation panel 17, the encoder 42a on the leader 4, the clamp body 451, and the excavator control unit 192.

[0046] The encoder 42a is a sensor that measures the distance traveled in the vertical direction of the lifting device 42. In this embodiment, as shown in Figure 1, it measures the distance between the head of the leader 4 and the upper end of the lifting device 42. The placement is not limited to this; it can be placed in any position where the amount of movement when the lifting device 42 moves up or down from a stationary state can be measured.

[0047] When the arithmetic control unit 182 receives a closing operation signal for the clamp body 451 from the clamp operation panel 17, it controls the clamp body 451 to close. On the other hand, when it receives an opening operation signal for the clamp body 451 from the clamp operation panel 17, it determines whether the operation that sent the opening operation signal was an error. Based on the determination result, it controls whether to execute or not execute the opening operation of the clamp body 451.

[0048] ≪Procedure for detecting user error≫ The operation of the clamp control unit 18 when a worker presses the open button on the clamp control panel 17 will be explained below with reference to Figures 4 and 5.

[0049] First, when a worker presses the open button on the clamp control panel 17 to request the opening operation, an opening operation signal for the clamp body 451 is transmitted to the clamp control unit 18. Upon receiving the opening operation signal via the input unit 181, the clamp control unit 182 transmits an information signal to the excavator control unit 192 via the output unit 183 from the calculation control unit 182 to raise or lower the lifting device 42.

[0050] Upon receiving the information signal, the excavator control unit 192 controls the operation of the lifting device 42 to raise it. Then, the clamp control unit 18 performs calculations in the calculation control unit 182 based on the measurement data from the encoder 42a, which is received in real time via the input unit 181, and the previously stored allowable upper limit value.

[0051] The calculation involves determining the amount of movement of the lifting device 42 after receiving the upward signal, based on the measurement data, and comparing this amount of movement with a pre-stored allowable upper limit. The allowable upper limit is the upper limit of movement at which it can be determined that no movement has occurred after the upward signal has been transmitted to the lifting device 42. This is set considering that even when no movement occurs in the lifting device 42, movement may be measured due to various conditions such as the amount of expansion and contraction of the rod 20 caused by temperature differences in the outside air, the amount of play in the joint structure 50, and the resolution of the encoder 42a.

[0052] Therefore, when setting the permissible upper limit, the above conditions should be taken into consideration according to the site conditions and set appropriately. Note that the state in which there is no movement of the lifting device 42 means that the rod 20 is connected to the drive shaft 7 and is gripped by the clamping device 45, and the rod bodies 30 constituting the rod 20 are soundly connected to each other via the joint structure 50.

[0053] ≪When the lifting device moves upward: In case of misoperation≫ If the amount of upward movement of the lifting device 42 is greater than the allowable upper limit, it can be detected that the rod 20, which is inserted into the borehole H, is being held only by the clamp body 451 of the clamping device 45. In other words, it can be detected that the situation is as shown in Figure 3(a), or, as shown in Figure 2(b), that the connecting pin 34 of the joint structure 50 located above the clamping device 45 has been removed, and the connection between the convex joint 32 and the concave joint 33 has been released.

[0054] The arithmetic control unit 182 then determines that the open operation signal for the clamp body 451 transmitted from the clamp operation panel 17 is an error and does not perform the open operation. At the same time, it sends an error display command to the clamp operation panel 17 via the output unit 183, for example, and displays an error image on the display 171 provided on the clamp operation panel 17 to notify the system that the operation was not performed.

[0055] Thus, when the rod 20 is gripped by the clamping device 45, and the lifting device 42 detects an upward movement exceeding the allowable upward value based on the measurement data from the encoder 42a, the clamping control unit 18 is configured to refrain from opening the rod 20 and maintain the gripping state. This makes it possible to prevent the drilling head 10 and rod 20 from falling into the drilling hole H even if an opening signal to release the grip on the rod 20 is sent from the clamping control panel 17 due to operator error or unforeseen circumstances.

[0056] ≪If the lifting device does not move upward: If there is no error in operation≫ If the amount of upward movement of the lifting device 42 is less than the allowable upper limit, the calculation control unit 182 can detect that the rod 20 inserted into the borehole H is connected to the drive shaft 7 and gripped by the clamping device 45, and that the rod bodies 30 constituting the rod 20 are properly connected to each other via the joint structure 50. In this case, the calculation control unit 182 determines that the opening operation signal of the clamp body 451 transmitted from the clamp operation panel 17 is a correct operation and executes the opening operation of the clamp body 451.

[0057] The excavator of the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0058] In this embodiment, an encoder 42a is used as the movement detection means, but the invention is not limited to this, and any device capable of detecting the upward and downward movement of the lifting device 42, such as a distance sensor, may be used. Furthermore, it is not necessary to directly measure the distance traveled. For example, if a hydraulic lifting system is used for the lifting device 42, a pressure sensor may be provided as the movement detection means, and the upward and downward movement of the lifting device 42 may be detected based on the pressure sensor.

[0059] Furthermore, in this embodiment, a so-called hexagonal joint pin type joint structure 50 is used as the joint structure 50, employing a hexagonal tube for the convex joint 32, but it is not limited to this. Any configuration that allows the pipe material 31 to be connected in the axial direction may be adopted.

[0060] Furthermore, in this embodiment, if the open operation signal of the clamp body 451 transmitted from the clamp operation panel 17 to the clamp control unit 18 is determined to be an error, an error image is displayed on the display 171 to notify that the operation was not performed. However, any method or means of notification may be adopted.

[0061] 1. Excavator 2 Crawler Track 3. Upper rotating body 4 Leaders 41 Guide 42 Lifting device 42a Encoder (movement detection means) 43 Telescopic device 44 Telescopic device 45 Clamping device 451 Clamp body 5 Fluid supply pipe 6 Swivel joints 7 Drive shaft 8 Rotating device 9 Excitation device 10 drilling heads 11 Shaft 12 Stirring blade 13. Excavation blade body 14-bit 15 tip bits 16 Fluid outlet 17. Clamp control panel 171 displays 18 Clamp control unit 181 Input section 182 Arithmetic Control Unit 183 Output section 191 Excavator control panel 192 Excavator Control Unit 20 rods 30 Rod body 31 Piping material 32 Convex joint 33 Recessed joint 34 connection pins 50 Joint Structure H drilled hole V Vacuum Hose S Stabilizing Solution 100 Drilling stirring device 110 Guide member 120 Chuck mechanism 130 Rotating means 140 Swivel Fittings 150 rods 160 steel pipe 200 drilling bits P Soil Cement Column

Claims

[Claim 1] An excavator comprising a plurality of rod bodies connected via a joint structure, each having an excavation head attached to its tip, wherein rotational force and vertical vibration are applied to the rod while the excavation head excavates the ground, A clamping device for gripping the aforementioned rod, A clamp control unit that controls the operation of the clamping device, A lifting device for raising and lowering the aforementioned rod, An excavator control unit that controls the operation of the lifting device, The device comprises a movement detection means for detecting the movement of the lifting device, The clamp control unit is Before performing the opening operation of the clamp device, the lifting device is raised via the excavator control unit, and the upward movement of the lifting device is detected based on the movement detection means, An excavator characterized by determining that the rod is gripped only by the clamping device and being configured to maintain the gripping state of the rod.

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