Drilling method and drilling device

Abstract

To propose a drilling method and a drilling device capable of grasping a drilling length more accurately and without labor as compared with conventional ones.SOLUTION: A drilling method for drilling a hole in the ground to a desired drilling length using a drilling device equipped with a hammer, a measuring unit, a clamp, a memory unit, and a control unit, includes: a step of measuring a drilling start position; a step of calculating a first drilling length; a first addition step of adding a new casing and adding 1 to the number N of casing additions if an amount of change from a first drilling end position to a first addition position is equal to or greater than a predetermined comparison value; a second or subsequent addition step of adding a new casing, measuring an addition position of the hammer in this state, and adding 1 to the number N of casing additions if the amount of change from the drilling end position to the addition position is equal to or greater than a predetermined comparison value, the second or subsequent addition step of performing the addition step A times; a step of grasping the drilling length just before a completion of drilling; and a step of drilling the ground until the drilling length just before the completion of drilling becomes the desired drilling length.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a hole drilling method and a hole drilling apparatus, and more particularly to a hole drilling method and a hole drilling apparatus capable of grasping the hole drilling length. [Background technology]

[0002] For example, when drilling a hole in a sloping ground, a drilling device as shown in FIG. 11 of Patent Document 1 is used. This type of drilling device includes a guide cell, a hammer that can move back and forth relative to the guide cell and has a casing attached to its tip (in Patent Document 1, it is configured to include a shank rod 3A that connects a drifter 3 and a swivel 5, and a swivel shoe 6), and a clamp (tip guide 7). The hammer is driven with the clamp open, and the casing is rotated and advanced to drill a hole. After drilling to a certain length, a new casing is added between the casing attached to the drilling device and the hammer, and drilling is continued, so that the ground can be drilled to the desired length.

[0003] When drilling a hole, it is necessary to check whether it has been drilled to the intended length. Conventionally, the drilled length has been checked by inserting a gauge rod into the casing after drilling and having the worker read the scale on the gauge rod, or by counting the number of casings used by the worker to calculate the total length of the casing and measuring the remaining length of the casing protruding from the ground after drilling, and then calculating the difference between the total length of the casing and the remaining length of the casing protruding from the ground. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 3-63383 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method using a measuring stick requires a separate task after drilling, which increases the number of man-hours and requires a lot of time. Also, if the total length of the casing is determined by the number of casings added, it is not only time-consuming but also there is a risk of miscounting. Also, whether using a measuring stick or measuring the remaining length of the casing, there is a risk of misreading the scale.

[0006] It is possible to provide a measuring means for measuring the movement of the hammer in the drilling device as shown in Patent Document 1, calculate the drilling length per casing from the movement of the hammer that moves with the casing, and calculate the total drilling length by accumulating the drilling length of each casing obtained each time a casing is added. However, the inventors of the present application confirmed that this method generates a large error.

[0007] As described above, the hammer has a shank rod connecting the drifter and the swivel, and there is a play (about 1 to 2 cm) between them in the length direction. When the inventor confirmed that the casing being drilled, which was held by the clamp when the casing was added, behaved in such a way that it would extend by this play due to its own weight when a new casing was added and the clamp was released. In other words, there is a risk of an error of about 1 to 2 cm occurring each time the casing is added. For this reason, for example, when drilling holes using 40 casings each 1.5 m long, there is a risk of an error of about 40 to 80 cm occurring with respect to the target drilling length of 60 m.

[0008] In view of these problems, the present invention aims to propose a hole-drilling method and a hole-drilling device that can grasp the hole-drilling length more accurately and with less effort than conventional methods. [Means for solving the problem]

[0009] The present invention provides a drilling method for drilling a hole in the ground to a desired drilling length with the casing by using a drilling device including a guide cell, a hammer that is movable back and forth relative to the guide cell, has a casing attached to its tip, and applies a force from the rear to the front together with a rotational force to the casing, a measuring unit that measures the position of the hammer in the forward and backward directions relative to the guide cell, a clamp that is provided on the guide cell and can hold the casing, a memory unit that stores various information including a casing length that is the length of the casing and a number N of casing extensions that is the number of casings to be added during drilling (wherein N is an integer whose initial value is 0), and a control unit that controls the driving of the hammer and the clamp and performs calculations based on information from the measuring unit and the various information stored in the memory unit, the method comprising the steps of: holding the casing by the clamp with the tip of the casing in contact with the ground or with a predetermined gap therebetween, and measuring the hole drilling start position of the hammer in this state with the measuring unit; and releasing the holding of the casing by the clamp and measuring the hole drilling start position of the hammer by the measuring unit. a step of driving the hammer to drill a hole in the ground, drilling to a predetermined length, and then holding the casing with the clamp, measuring a first drilling end position of the hammer in this state with the measuring unit, and calculating a first drilling length from the drilling start position and the first drilling end position with the control unit, and further storing the first drilling length in the memory unit; a step of retracting the hammer to add a new casing to the rear end of the casing held by the clamp, and moving the hammer forward to attach the new casing to the front end, and a first replenishment step in which the first replenishment position of the hammer is measured by the measuring unit, and if the amount of change from the first drilling end position to the first replenishment position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number of casing replenishments N stored in the memory unit; the clamp is released from holding the casing, the hammer is driven to drill a hole in the ground, and after drilling to a predetermined length, the casing is held by the clamp, and the hammer's drilling end position in this state is measured by the measuring unit; anda second or subsequent casing addition process in which the hammer is retracted to add a new casing to the rear end of the casing held by the clamp, and then the hammer is advanced to attach the new casing to the front end, and the hammer's addition position in this state is measured by the measuring unit, and if the amount of change from the end position of the hole drilling to the addition position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number N of casing additions stored in the memory unit; and After the second or subsequent addition process, when drilling the ground to the desired length, a process of determining the drilling length just before the completion of drilling by the following formula (1); Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the replenishment position when executed A times - the first replenishment position) (1) and releasing the clamp from its hold on the casing to drive the hammer, thereby drilling the ground until the hole length just before completion of drilling becomes the desired hole length.

[0010] In such a drilling method, the memory unit further stores a second casing length, which is the length of the second casing, and a number M of second casings to be added during drilling (wherein M is an integer with an initial value of 0), and the second and subsequent adding steps include releasing the clamp from holding the casing and driving the hammer to drill a hole in the ground, drilling to a predetermined length, holding the casing with the clamp, measuring a drilling end position of the hammer in this state with the measuring unit, and then a step of retracting the hammer to add a new casing to the rear end of the casing held by the clamp, and then moving the hammer forward to attach the new casing to the front end, measuring the add-on position of the hammer in this state with the measuring unit, and adding 1 to the number N of casings to be added stored in the memory unit when the amount of change from the end position of the hole drilling to the add-on position is equal to or greater than a predetermined comparison value in the control unit, and executing the add-on step (AB) times (where B is A> B), releasing the clamp from holding the casing and driving the hammer to drill a hole in the ground, drilling to a predetermined length and then holding the casing with the clamp, measuring the additional drilling end position of the hammer in this state with the measuring unit, then retreating the hammer to add the second casing to the rear end of the casing held by the clamp, and then moving the hammer forward to attach the second casing to the front end, measuring the additional addition position of the hammer in this state with the measuring unit, and if the amount of change from the additional drilling end position to the additional addition position is equal to or greater than a predetermined comparison value, adding 1 to the number M of second casing additions stored in the memory unit, and performing the additional addition process B times. In this case, it is preferable that the step of determining the drilling length immediately before the completion of drilling is performed by determining the drilling length immediately before the completion of drilling using the following formula (2) when drilling the ground to the desired length after the second and subsequent addition processes. Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the second casing length × M) + (the additional replenishment position when executed B times - the first replenishment position) (2)

[0011] The present invention also provides a drilling device comprising a guide cell, a hammer that is movable back and forth relative to the guide cell, has a casing attached to its tip, and applies a force from the rear to the front together with a rotational force to the casing, a measurement unit that measures the position of the hammer in the forward and backward directions relative to the guide cell, a clamp that is provided on the guide cell and can hold the casing, a memory unit that stores various information including a casing length that is the length of the casing and a number N of casing extensions that is the number of casings to be added during drilling (where N is an integer with an initial value of 0), and a control unit that controls the driving of the hammer and the clamp and performs calculations based on information from the measurement unit and the various information stored in the memory unit, wherein the control unit performs the steps of holding the casing with the clamp with the tip of the casing in contact with the ground or with a predetermined gap therebetween, and measuring the drilling start position of the hammer in this state with the measurement unit, and releasing the clamp from holding the casing and driving the hammer to drill a hole in the ground. a step of holding the casing with the clamp after drilling to a predetermined length, measuring a first drilling end position of the hammer in this state with the measuring unit, calculating a first drilling length from the drilling start position and the first drilling end position with the control unit, and storing the first drilling length in the memory unit; a step of retracting the hammer to add a new casing to the rear end of the casing held by the clamp and moving the hammer forward to attach the new casing to the front end, and a first replenishment step in which the first replenishment position of the casing is measured by the measuring unit, and if the amount of change from the first drilling end position to the first replenishment position by the control unit is equal to or greater than a predetermined comparison value, the casing is released from the clamp's hold on the casing, the hammer is driven to drill a hole in the ground, the casing is held by the clamp after drilling to a predetermined length, and the hammer's drilling end position in this state is measured by the measuring unit, and thenThe hammer is retreated to add a new casing to the rear end of the casing held by the clamp, and then the hammer is advanced to attach the new casing to the front end. The measuring unit measures the add-on position of the hammer in this state, and if the control unit determines that the amount of change from the drilling end position to the add-on position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number of casings N stored in the memory unit. This add-on process is a second or subsequent add-on process in which the add-on process is performed A times (where A is an integer equal to or greater than 1), and after the second or subsequent add-on process, when drilling the ground to the desired length, a process of determining the drilling length immediately before the completion of drilling using the following formula (1): Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the replenishment position when executed A times - the first replenishment position) (1) The drilling device also carries out a step of releasing the clamp from its hold on the casing and driving the hammer to drill a hole in the ground until the hole length just before completion of drilling reaches the desired hole length. Effect of the Invention

[0012] According to the above-mentioned drilling method of the present invention, it is possible to confirm that the casing has been extended by checking that the amount of change from the first drilling end position to the first replenishment position, and from the drilling end position to the replenishment position, are equal to or greater than a predetermined comparison value. Furthermore, the drilling length is calculated using the number of casings for which replenishment has been confirmed and the casing length, and since errors due to play between the components that make up the hammer are not accumulated, the drilling length can be accurately determined. Furthermore, since the drilling length is calculated when drilling, it is possible to know the drilling length without any hassle. [Brief description of the drawings]

[0013] [Figure 1A] 1 is a schematic diagram showing one embodiment of a hole drilling device according to the present invention; [Figure 1B] 1B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 1A. [Diagram 2] 1B is a diagram showing the display unit of the hole drilling device shown in FIG. 1A in an initial state. [Diagram 3] FIG. 1B is a diagram showing an operation flow of the hole drilling device shown in FIG. 1A. [Figure 4A] FIG. 1B is an explanatory diagram of the hole drilling method performed subsequent to FIG. 1A. [Figure 4B] 4B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 4A. [Figure 5A] FIG. 4B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 4A. [Figure 5B] 5B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 5A. [Figure 6A] FIG. 5B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 5A. [Figure 6B] 6B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 6A. [Figure 7A] FIG. 6B is an explanatory diagram of the hole drilling method performed subsequent to FIG. 6A. [Figure 7B] 7B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 7A. [Figure 8A] FIG. 7B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 7A. [Figure 8B] 8B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 8A. [Figure 9A] FIG. 8B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 8A. [Figure 9B] 9B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 9A. [Figure 10A] FIG. 9B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 9A. [Figure 10B] 10B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 10A. [Figure 11A] FIG. 10B is an explanatory diagram of the hole-drilling method performed subsequent to FIG. 10A. [Figure 11B] 11B is a diagram showing the display unit during operation of the hole drilling device shown in FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of a hole drilling method and a hole drilling device according to the present invention will be described with reference to the drawings.

[0015] Fig. 1A is a schematic diagram of a hole-drilling device 1 which is one embodiment of the hole-drilling device according to the present invention. The hole-drilling device 1 of this embodiment includes a guide cell 2, a hammer 3, a measuring unit 4, a clamp 5, and a breaker 6. The hole-drilling device 1 also includes a display unit 7 shown in Fig. 1B, as well as a control unit, a storage unit, and an input unit, none of which are shown.

[0016] The guide cell 2 extends linearly and has a long shape. The guide cell 2 of this embodiment is supported by a base installed on the ground extending in the horizontal direction as shown in the figure so as to form a predetermined angle (for example, perpendicular to the inclined slope) with respect to the inclined ground G where the hole is to be drilled.

[0017] The hammer 3 is configured using members such as a drifter, a swivel, a shank rod, and a swivel shoe, for example, as shown in Patent Document 1. The hammer 3 is supported so as to be movable along the longitudinal direction of the guide cell 2. The hammer 3 can move forward and backward with respect to the guide cell 2 by driving a moving means (for example, a hydraulic or electric motor) not shown. A tip portion 3a is provided in front of the hammer 3 to which a casing (a first casing C1 and a second casing C2, which will be described later in this embodiment) is attached. A thread portion (one is a male thread portion and the other is a female thread portion) is provided on the rear end portion and the tip portion 3a of the casing, and the casing is attached to the tip portion 3a by screwing the two together. The hammer 3 can apply a force from the rear to the front to the casing attached to the tip portion 3a by driving a force applying means (for example, a hydraulic rotational force, thrust, or impact force applying mechanism) not shown.

[0018] The measuring unit 4 is attached to the guide cell 2 behind the hammer 3. The measuring unit 4 in this embodiment is a laser range finder, and can measure the position of the hammer 3 in the forward / backward direction relative to the guide cell 2 by irradiating the hammer 3 with a laser and receiving the reflected light.

[0019] The clamps 5 are attached to the front of the guide cell 2. The clamps 5 in this embodiment are provided so as to face each other across the casing attached to the hammer 3, and each clamp 5 is provided with a rod that can move forward and backward relative to the casing. The casing can be clamped and held by driving a rod moving means (e.g., a hydraulic cylinder) not shown.

[0020] The breaker 6 is attached to the guide cell 2 behind the clamp 5. The breaker 6 is also provided facing the casing attached to the hammer 3, and can clamp the casing with a rod that can move back and forth relative to the casing. The breaker 6 can also rotate about the central axis of the casing relative to the clamp 5. With such a breaker 6, the rear end of the casing is held by the clamp 5, and the breaker 6 holding the tip 3a is rotated to release the screw engagement between the two, so that a new casing can be added to the rear end of the casing after the hammer 3 is retracted.

[0021] The display unit 7 has a function of displaying information relating to, for example, the operation of the drilling device 1. The display unit 7 is realized by, for example, a liquid crystal display or an organic EL display. In the initial state, the display unit 7 of this embodiment displays information as shown in Fig. 2, and during operation, displays information as shown in Fig. 1B.

[0022] The control unit has a function of controlling the hole drilling device 1 to execute various operations. The control unit is embodied by a computer such as a PLC (Programmable Logic Controller) or a PC (Personal Computer). The storage unit has a function of storing a program for operating the hole drilling device 1 and various information related to the hole drilling device 1. The storage unit is embodied by an internal storage device of the computer or an external storage device connected thereto. The input unit has a function of inputting various information related to the hole drilling device 1 to the control unit or the storage unit. The input unit is embodied by a keyboard, a mouse, or a touch panel. The input unit also includes a means for inputting information using boxes such as text boxes, combo boxes, and check boxes displayed on a display or the like, and a means for inputting information by clicking a displayed icon or the like with a mouse.

[0023] The control unit of this embodiment is electrically connected to the above-mentioned moving means, force applying means, rod moving means, measuring unit 4, display unit 7, input unit and memory unit. Here, the control unit has the function of reading the programs related to various operations of the hole drilling device 1 stored in the memory unit, sending signals to the moving means, force applying means and rod moving means based on the programs, thereby driving these means. The control unit also has the function of grasping the driving state of these means based on signals sent from these means, and the function of storing information obtained from these means in the memory unit. Furthermore, the control unit also has the function of displaying information related to the operation of the hole drilling device 1 on the display unit 7, and storing information input from the input unit in the memory unit.

[0024] The memory unit of this embodiment has the function of storing programs related to the various operations of the above-mentioned drilling device 1, the length of the casings to be used (the casing length, which is the length of the first casing C1, and the second casing length, which is the length of the second casing C2), the number of casings to be used (the number of first casings C1 and the number of second casings C2), the number of casings to be added during drilling (the number of casing additions N, which is the number of first casings to be added during drilling (where N is an integer whose initial value is 0), and the number of second casing additions M, which is the number of second casings to be added during drilling (where M is an integer whose initial value is 0)), as well as information obtained from various means equipped with the drilling device 1.

[0025] Next, an embodiment of a hole drilling method using the above-mentioned hole drilling device 1 will be described.

[0026] First, when starting drilling with the hole-drilling device 1, a casing is attached to the hole-drilling device 1 (step S1 shown in FIG. 3). In this embodiment, two types of casings are used: a first casing C1 shown in FIG. 1A and a second casing C2 shown in FIG. 10A. When starting drilling, two first casings C1 are attached to the hole-drilling device 1 as shown in FIG. 1A. In the following description, for convenience, the first casing C1 and the second casing C2 are numbered (1), (2), ... (28) in the order of use in drilling. In the state shown in FIG. 1A, the first first casing C1(1) is held by the clamp 5, and the second first casing C1(2) is attached to the rear end of the first casing C1(1). The tip 3a of the hammer 3 is attached to the rear end of the second first casing C1(2). At this time, the tip of the first casing C1(1) is in contact with the ground G where drilling is to be performed.

[0027] In addition, when starting drilling, initial information is input from the input unit (step S2 shown in FIG. 3). When the initial information is input, the control unit stores the initial information in the storage unit and also displays the initial information on the display unit 7 as shown in FIG. 2. In this embodiment, drilling is performed with a design value of a drilling length of 40.00 m and a drilling angle of 30.0°. In addition, in drilling, a total of 27 first casings C1 and a total of 1 second casing C2 are used. The length of the first casing C1 is 1.50 m, and the length of the second casing C2 is 1.00 m. In this embodiment, after all the first casings C1 are used in drilling, the second casing C2 is used. Here, the initial number of casings shown in FIG. 2 is the number of casings attached to the drilling device 1 at the stage of starting drilling as shown in FIG. 1A. In this embodiment, the first casing C1(1) and the first casing C1(2) are attached to the drilling device 1, so the initial number of casings is two. The control unit also calculates the total casing length from the length and number of the first casing C1 and the length and number of the second casing C2, and calculates the remaining length of the casing protruding from the ground after drilling by subtracting the design value of the drilling length from the total casing length, and displays the total casing length and remaining length on the display unit 7 as shown in Figure 2.

[0028] Next, the measuring unit 4 measures the position of the hammer 3 in the advancing / retracting direction relative to the guide cell 2 (step S3 shown in FIG. 3). In this embodiment, the position of the hammer 3 in the advancing / retracting direction when the first casing C1(1) is held by the clamp 5 as shown in FIG. 1A (the hole-drilling start position of the hammer 3) is 0.90 m. The control unit stores in the memory unit that the hole-drilling start position of the hammer 3 is 0.90 m. The control unit also displays on the display unit 7 that the current value is 0.90 m as the current position of the hammer 3 in the advancing / retracting direction as shown in FIG. 1B. The control unit also displays on the display unit 7 that the hole-drilling length is 0.00 m because the hole-drilling has not yet started. Furthermore, the control unit displays on the display unit 7 that the number of casings currently attached to the hole-drilling device 1 is two because the initial number of casings input by the input unit is two.

[0029] In the state shown in Fig. 1A, the tip of the first casing C1(1) may be in a state where a predetermined gap is opened with respect to the ground G where the hole is to be drilled. In this case, however, the hole drilling device 1 is provided with a function to subtract this gap from the hole drilling length shown in Fig. 1B (for example, if the gap is 0.20 m, the hole drilling length in Fig. 1A is set to -0.20 m), so that this gap is reflected in the hole drilling length.

[0030] Next, when the start button (not shown) is pressed, the control unit releases the clamp 5 from holding the first casing C1(1), and further drives the hammer 3 to drill the ground G with the first casing C1(1) to a predetermined length, for example, as shown in FIG. 4A. In the state shown in FIG. 4A, the rear end of the first casing C1(2) is held by the clamp 5, and the tip 3a is held by the breaker 6. When the breaker 6 is rotated relative to the clamp 5 in this state, the screw engagement between the rear end of the first casing C1(2) and the tip 3a is released. In this state, the measurement unit 4 measures the position of the hammer 3 (first drilling end position). The measured first drilling end position of the hammer 3 is stored in the memory unit. The control unit then calculates the first drilling length from the drilling start position and the first drilling end position of the hammer 3 stored in the memory unit, and further stores the first drilling length in the memory unit (step S4 shown in FIG. 3).

[0031] To explain the above process in detail, the position of the hammer 3 measured by the measuring unit 4 in the state shown in Fig. 4A (first drilling end position) is 2.58 m as shown in Fig. 4B. Here, the control unit calculates the amount of change (2.58-0.90=1.68) from the drilling start position of the hammer 3 stored in the memory unit (0.90 m shown in Fig. 1B) and the first drilling end position (2.58 m), and stores this value in the memory unit as the first drilling length. The control unit also displays the calculated amount of change as the current drilling length (1.68 m) as shown in Fig. 4B.

[0032] After that, the breaker 6 is rotated relative to the clamp 5 to release the screw engagement between the rear end of the first casing C1(2) and the tip 3a, and the hammer 3 is moved backward as shown in FIG. 5A. The hammer 3 shown in FIG. 5A is located 0.50 m from the measuring unit 4 as shown in FIG. 5B. Then, a new casing, the first casing C1(3), is added to the rear end of the first casing C1(2) held by the clamp 5, and the hammer 3 is advanced as shown in FIG. 6A to attach the rear end of the first casing C1(3) to the tip 3a. In this state, the measuring unit 4 measures the position of the hammer 3 (first addition position). The measured first addition position of the hammer 3 is stored in the memory unit. Then, the control unit calculates the amount of change from the first drilling end position of the hammer 3 stored in the memory unit to the first addition position, and judges whether this amount of change is equal to or greater than a predetermined comparison value. This process by the control unit is performed to determine whether a new casing has been added, and the predetermined comparison value is set according to the length of the casing to be added and various errors (errors during measurement by the measuring unit 4 and errors in the overall length when the casing is added). The predetermined comparison value is stored in the memory unit. If the amount of change is equal to or greater than the predetermined comparison value, 1 is added to the number N of casings to be added that is stored in the memory unit. In this specification, the above process is referred to as the first addition process (process S5 shown in FIG. 3).

[0033] To explain the above process in detail, in the state where the rear end of the first casing C1(3) is attached to the tip 3a as shown in FIG. 6A, the first casing addition position of the hammer 3 measured by the measuring unit 4 is 1.08 m as shown in FIG. 6B. Here, the control unit calculates the change amount (2.58-1.08=1.50) from the first drilling end position (2.58 m) of the hammer 3 stored in the memory unit to the first casing addition position (1.08 m). In the memory unit of this embodiment, a value (1.43) of about 95% of the length of the first casing C1 is stored as a predetermined comparison value. Then, the control unit adds 1 to the number of casing additions N stored in the memory unit when the change amount (1.50) is equal to or greater than the predetermined comparison value (1.43). That is, since the initial value of the number of casing additions N is 0, the number of casing additions N becomes 1 after this process is executed. Furthermore, the control unit also adds 1 to the number of casings displayed on the display unit 7, so that the number of casings displayed becomes 3, as shown in Fig. 6B. The control unit also determines that the hole drilling length in the state shown in Fig. 5A (1.68 m as shown in Fig. 5B) will increase to 1.50 m as the first casing C1(3) is extended and drilling continues, and causes the display unit 7 to display the hole drilling length as 1.68 to 3.18 m, as shown in Fig. 6B.

[0034] The drilling device 1 may also have a function of issuing a warning (for example, a function of displaying on the display unit 7 a message indicating that the casing is not correctly attached or of emitting an alarm sound) if the amount of change in the hammer 3 from the first drilling end position to the first addition position is smaller than a predetermined comparison value (for example, if the first casing C1 (3) is not attached).

[0035] After the first casing addition process (first addition process) is performed as described above, the second and subsequent addition processes are performed (process S6 shown in FIG. 3). In the second and subsequent addition processes, the clamp 5 releases the casing from its hold, drives the hammer 3 to drill a hole in the ground G with the casing, and after drilling to a predetermined length, the clamp 5 holds the casing. The position of the hammer 3 in this state (hole drilling end position) is measured by the measuring unit 4. Next, the hammer 3 is moved backward to add a new casing to the rear end of the casing held by the clamp 5, and then the hammer 3 is moved forward to attach the new casing to the tip 3a. The position of the hammer 3 in this state (addition position) is measured by the measuring unit 4, and if the amount of change from the hole drilling end position to the addition position in the control unit is equal to or greater than a predetermined comparison value, the addition process is performed one or more times to add 1 to the number N of casings to be added stored in the memory unit.

[0036] To explain the above steps in detail, after executing the first addition step shown in FIG. 6A, the control unit releases the clamp 5 from holding the first casing C1(2) and further drives the hammer 3 to drill the ground G to a predetermined length, for example, as shown in FIG. 7A. In the state shown in FIG. 7A, the rear end of the first casing C1(3) is held by the clamp 5 and the tip 3a is held by the breaker 6. When the breaker 6 is rotated relative to the clamp 5 in this state, the screw engagement between the rear end of the first casing C1(3) and the tip 3a is released. In this state, the position of the hammer 3 measured by the measuring unit 4 (the end position of the second drilling) is 2.60 m as shown in FIG. 7B. Next, the breaker 6 is rotated relative to the clamp 5 to release the screw engagement between the rear end of the first casing C1(3) and the front end 3a, the hammer 3 is moved backward, and a new casing, the first casing C1(4), is added to the rear end of the first casing C1(3) held by the clamp 5 as shown in FIG. 8A, and then the hammer 3 is moved forward to attach the rear end of the first casing C1(4) to the front end 3a. In this state, the measuring unit 4 measures the position of the hammer 3 (the second addition position). In this embodiment, the second addition position of the hammer 3 is 1.10 m as shown in FIG. 8B. The measured second addition position of the hammer 3 is recorded in the memory unit. Here, the control unit calculates the amount of change (2.60-1.10=1.50) from the second drilling end position (2.60m) of the hammer 3 stored in the memory unit to the second replenishment position (1.10m). Then, since the amount of change is equal to or greater than the above-mentioned comparison value (1.43), it is determined that the first casing C1 (4) has been replenished, and 1 is added to the number of casings replenished N stored in the memory unit. That is, in this state, the number of casings replenished N becomes 2. Furthermore, the control unit also adds 1 to the number of casings displayed on the display unit 7, and the number of casings displayed becomes 4 as shown in FIG. 8B. Also, the control unit determines that the drilling length in the state shown in FIG. 8A will be further extended to 1.50m if drilling is continued in the future due to the replenishment of the first casing C1 (4), and causes the display unit 7 to display the drilling length as 3.18-4.68m as shown in FIG. 8B. Such an adding step is executed A times or more (where A is an integer equal to or greater than 1) (step S6a shown in FIG. 3). In this embodiment, the adding step is executed 24 times.

[0037] FIG. 9A shows a state in which, after the extension process is performed 24 times, the clamp 5 releases the first casing C1 (27) from its hold, the hammer 3 is driven to drill the ground G, and the clamp 5 holds the first casing C1 (27) after drilling to a predetermined length. In the state shown in FIG. 9A, the rear end of the first casing C1 (27) is held by the clamp 5 and the tip 3a is held by the breaker 6. When the breaker 6 is rotated relative to the clamp 5, the screw engagement between the rear end of the first casing C1 (27) and the tip 3a is released. In this state, the position of the hammer 3 measured by the measuring unit 4 (additional drilling end position) is 2.61 m as shown in FIG. 9B. Next, the breaker 6 is rotated relative to the clamp 5 to release the screw engagement between the rear end of the first casing C1 (27) and the front end 3a, the hammer 3 is moved backward, and a new casing, the second casing C2 (28), is added to the rear end of the first casing C1 (27) held by the clamp 5 as shown in FIG. 10A. Then, the hammer 3 is moved forward to attach the rear end of the second casing C2 (28) to the front end 3a. In this state, the measuring unit 4 measures the position of the hammer 3 (additional addition position). In this embodiment, the addition position of the hammer 3 is 1.61 m as shown in FIG. 10B. The measured addition position of the hammer 3 is recorded in the memory unit. Here, the control unit calculates the change amount (2.61-1.61=1.00) from the additional drilling end position (2.61m) of the hammer 3 stored in the memory unit to the additional addition position (1.61m). Then, it is judged whether the change amount is equal to or greater than a predetermined comparison value. In the memory unit of this embodiment, a value of 95% (0.95) of the length of the second casing C2 is stored as the predetermined comparison value. Then, the control unit determines that the second casing C2 (28) has been added because the change amount (1.00) is equal to or greater than the predetermined comparison value (0.95), and adds 1 to the number M of second casing additions stored in the memory unit. That is, since the initial value of the number M of second casing additions is 0, after this process is executed, the number M of second casing additions becomes 1. Furthermore, the control unit also adds 1 to the number of casings displayed so far as the number of casings displayed on the display unit 7, and the number of casings displayed becomes 28 as shown in FIG. 10B. The length of the hole in the display unit 7 shown in FIG. 10B will be described later.

[0038] The process (additional extension process) described with reference to Figures 9A and 10A uses one second casing C2 in this embodiment, and this process is performed once, but when multiple second casings C2 are used to drill holes, the additional extension process is performed a number of times corresponding to the number of second casings C2 (process S6b shown in Figure 3).

[0039] Here, the control unit calculates the hole drilling length (the hole drilling length immediately before the completion of drilling) after performing the additional addition process B times (where B is an integer of 1 or more such that A>B when the second and subsequent addition processes are set to A times as described above) based on the following formula (step S7 shown in Figure 3).

[0040] Drilling length just before drilling is completed = 1st drilling length + (casing length × (N-1)) + (2nd casing length × M) + (additional replenishment position when the additional replenishment process is performed B times - 1st replenishment position) Here, "N" is the number of first casings C1 to be added during drilling as described above, and "M" is the number of second casings C2 to be added during drilling. As is clear from the above formula, when calculating the hole drilling length immediately before the completion of drilling (in this embodiment, the hole drilling length from the state in which the tip of the first casing C1 (1) shown in FIG. 1A contacts the ground G to the state in which the rear end of the first casing C1 (27) is held by the clamp 5 shown in FIG. 10A), from the state shown in FIG. 4A onwards, the hole drilling length is calculated based on the casing length, which is the length of the first casing C1, and the number of the first casings C1 added during drilling, and the second casing length, which is the length of the second casing C2, and the number of the second casings C2 added during drilling. In other words, since errors due to play between the members constituting the hammer 3 are not accumulated, the hole drilling length can be grasped more accurately. In addition, the position of the hammer 3 just before the last casing is added (as shown in FIG. 9A, the rear end of the first casing C1 (27) is held by the clamp 5 and the tip 3a of the hammer 3 is held by the breaker 6) may not match the position at which the first drilling is completed (as shown in FIG. 4A and FIG. 5A, in this embodiment). In other words, the hole length will change depending on this difference in position. For this reason, when calculating the hole length just before the completion of drilling, the influence of the above-mentioned difference in position is eliminated by including "the additional addition position when the additional addition process is performed B times - the first addition position" as described above.

[0041] Regarding the above-mentioned drilling length immediately before completion of drilling, in this embodiment, the first drilling length is 1.68 m (see FIG. 4B), the casing length (length of the first casing C1) is 1.50 m, N is 25, M is 1, the additional addition position when the additional addition process is performed once is 1.61 m (see FIG. 10B), and the first addition position is 1.08 m (see FIG. 6B), so the drilling length immediately before completion of drilling is 39.21 m. The control unit stores in the memory unit that the drilling length immediately before completion of drilling is 39.21 m. The control unit also displays on the display unit 7, as shown in FIG. 10B, that the current drilling length (the drilling length immediately before completion of drilling) is 39.21 m.

[0042] Thereafter, as shown in FIG. 11A, the clamp 5 releases the second casing C2 (28) from its hold, and the hammer 3 is driven to drill the ground G until the hole length immediately before the completion of the hole drilling described above becomes the desired hole length (step S8 shown in FIG. 3). In this embodiment, in order to provide a slight margin with respect to the design value of 40.00 m (see FIG. 2), the control unit drives the hammer 3 until the hole length becomes 40.30 m as shown in FIG. 11B. Note that the state shown in FIG. 11A is a state in which the rear end of the second casing C2 (28) is held by the clamp 5, and the tip 3a is held by the breaker 6. When the breaker 6 is rotated relative to the clamp 5, the screw engagement between the rear end of the second casing C2 (28) and the tip 3a can be released.

[0043] By using the hole-drilling device 1 to perform the above-described hole-drilling operation, the hole-drilling length can be determined more accurately and with less effort than in the past.

[0044] In the above embodiment, the drilling is performed using two types of casings (the first casing C1 and the second casing C2), but the casing may be of one type (for example, only the first casing C1). When drilling is performed using only the first casing C1, the drilling length just before the completion of the above-mentioned drilling is calculated based on the following formula. Drilling length just before drilling is completed = 1st drilling length + (casing length x (N-1)) + (addition position when the replenishment process is executed A times (where A is an integer of 1 or more) from the 2nd time onwards - 1st replenishment position) Here, "N" is the number of first casings C1 to be added during drilling, as described above.

[0045] Thereafter, the clamp 5 is released from holding the first casing C1, and the hammer 3 is driven to drill the ground G until the hole length just before the completion of drilling described above becomes the desired hole length.

[0046] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the spirit of the present invention described in the claims unless otherwise specifically limited in the above description. For example, the configuration of the above-mentioned embodiment can be appropriately added or deleted, and the configuration of one embodiment can be applied to another embodiment. Furthermore, the effects of the above-mentioned embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-mentioned effects.

[0047] For example, the measuring unit 4 described above was a laser range finder, but it is also possible to use a wire encoder that measures the position of the hammer 3 in the forward and backward direction based on the length of a wire, or to use an encoder that measures the amount of rotation of a moving means that moves the hammer 3 forward and backward, and calculate the position of the hammer 3 in the forward and backward direction from this amount of rotation. [Explanation of symbols]

[0048] 1: Drilling equipment 2: Guide cell 3: Hammer 3a:Tip 4: Measurement section 5: Clamp 6: Breaker 7: Display section C1: First casing C2: Second casing G: Ground

Claims

1. a hammer that can move back and forth relative to the guide cell and has a casing attached to its tip, and that applies a force from the rear to the front along with a rotational force to the casing; a measuring unit that measures the position of the hammer in the direction of movement relative to the guide cell; a clamp that is provided on the guide cell and can hold the casing; a memory unit that stores various information including a casing length that is the length of the casing and a number N of casing extensions that is the number of casings to be added during drilling (where N is an integer with an initial value of 0); and a control unit that controls the drive of the hammer and the clamp and performs calculations based on information from the measuring unit and the various information stored in the memory unit, A step of holding the casing by the clamp with the tip of the casing in contact with the ground or with a predetermined gap therebetween, and measuring the drilling start position of the hammer in this state with the measuring unit; a step of releasing the clamp from holding the casing and driving the hammer to drill a hole in the ground, and after drilling to a predetermined length, holding the casing with the clamp, measuring a first drilling end position of the hammer in this state with the measuring unit, and calculating a first drilling length from the drilling start position and the first drilling end position with the control unit, and further storing the first drilling length in the memory unit; a first addition process in which the hammer is retracted to add a new casing to the rear end of the casing held by the clamp and the hammer is advanced to attach the new casing to the front end, the first addition position of the hammer in this state is measured by the measuring unit, and if the amount of change from the first drilling end position to the first addition position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number N of casing additions stored in the memory unit; The clamp is released from holding the casing, and the hammer is driven to drill a hole in the ground. After drilling to a predetermined length, the casing is held by the clamp. The measurement unit measures the end position of the hammer in this state. The hammer is then moved backward to add a new casing to the rear end of the casing held by the clamp, and the hammer is then moved forward to attach the new casing to the front end. The measurement unit measures the add-on position of the hammer in this state, and if the amount of change from the end position of the drilling to the add-on position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number N of casings to be added that is stored in the memory unit. This is a second or subsequent add-on process in which the add-on process is performed A times (wherein A is an integer equal to or greater than 1). After the second or subsequent addition process, when drilling the ground to the desired length, a process of grasping the drilling length just before the completion of drilling by the following formula (1); Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the replenishment position when A times are performed - the first replenishment position) ... (1) and releasing the clamp from its hold on the casing to drive the hammer, thereby drilling the ground until the hole length just before completion of drilling becomes the desired hole length.

2. The memory unit further stores a second casing length, which is the length of the second casing, and a number M of second casing extensions, which is the number of pieces of the second casing to be extended during drilling (wherein M is an integer whose initial value is 0); The second and subsequent replenishment steps are The clamp is released from the casing to drive the hammer to drill a hole in the ground, and the casing is held by the clamp after drilling to a predetermined length. The measurement unit measures the end position of the hammer in this state, and then the hammer is moved backward to add a new casing to the rear end of the casing held by the clamp, and then the hammer is moved forward to attach the new casing to the front end. The measurement unit measures the add-on position of the hammer in this state, and the control unit adds 1 to the number N of casings to be added stored in the memory unit if the amount of change from the end position of the drilling to the add-on position is equal to or greater than a predetermined comparison value. The add-on process is performed (A-B) times (wherein B is an integer equal to or greater than 1 that satisfies A>B). the clamp is released from holding the casing, the hammer is driven to drill a hole in the ground, the casing is held by the clamp after drilling to a predetermined length, the measuring unit measures the additional hole drilling end position of the hammer in this state, the hammer is then moved backward to add the second casing to the rear end of the casing held by the clamp, the hammer is then moved forward to attach the second casing to the front end, the measuring unit measures the additional addition position of the hammer in this state, and if the amount of change from the additional hole drilling end position to the additional addition position is equal to or greater than a predetermined comparison value in the control unit, 1 is added to the number M of second casing additions stored in the memory unit, and the additional addition process is performed B times, The drilling method according to claim 1, wherein the step of determining the drilling length immediately before completion of drilling is performed by determining the drilling length immediately before completion of drilling using the following formula (2) when drilling the ground to the desired length after the second or subsequent extension step. Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the second casing length × M) + (the additional replenishment position when executed B times - the first replenishment position) ... (2)

3. a hammer that can move back and forth relative to the guide cell, has a casing attached to its tip, and applies a force from the rear to the front to the casing together with a rotational force; a measuring unit that measures the position of the hammer in the forward and backward directions relative to the guide cell; a clamp that is provided on the guide cell and can hold the casing; a memory unit that stores various information including a casing length, which is the length of the casing, and a number N of casing additions, which is the number of casings to be added during drilling (where N is an integer with an initial value of 0); and a control unit that controls the drive of the hammer and the clamp, and performs calculations based on information from the measuring unit and the various information stored in the memory unit, The control unit is A step of holding the casing by the clamp with the tip of the casing in contact with the ground or with a predetermined gap therebetween, and measuring the drilling start position of the hammer in this state with the measuring unit; a step of releasing the clamp from holding the casing and driving the hammer to drill a hole in the ground, and after drilling to a predetermined length, holding the casing with the clamp, measuring a first drilling end position of the hammer in this state with the measuring unit, and calculating a first drilling length from the drilling start position and the first drilling end position with the control unit, and further storing the first drilling length in the memory unit; a first addition process in which the hammer is retracted to add a new casing to the rear end of the casing held by the clamp and the hammer is advanced to attach the new casing to the front end, the first addition position of the hammer in this state is measured by the measuring unit, and if the amount of change from the first drilling end position to the first addition position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number N of casing additions stored in the memory unit; The clamp is released from holding the casing to drive the hammer to drill a hole in the ground, and after drilling to a predetermined length, the clamp holds the casing. The measurement unit measures the end position of the hammer in this state, and then the hammer is moved backward to add a new casing to the rear end of the casing held by the clamp, and then the hammer is moved forward to attach the new casing to the front end. The measurement unit measures the add-on position of the hammer in this state, and if the amount of change from the end position of the drilling to the add-on position is equal to or greater than a predetermined comparison value, the control unit adds 1 to the number N of casings to be added that is stored in the memory unit. This is a second or subsequent add-on process in which the add-on process is performed A times (wherein A is an integer equal to or greater than 1). After the second or subsequent addition process, when drilling the ground to the desired length, a process of grasping the drilling length just before the completion of drilling by the following formula (1); Drilling length just before completion of drilling = the first drilling length + (the casing length × (N-1)) + (the replenishment position when A times are performed - the first replenishment position) ... (1) The drilling device executes the steps of releasing the clamp from its hold on the casing and driving the hammer to drill a hole in the ground until the hole length just before completion of drilling becomes the desired hole length.

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