Automatic standard penetration test device and boring machine including the same

Abstract

To provide a striking device in which the entire device is made into a compact unit as a single device.SOLUTION: A hammer 201, a catcher 202, and a guide rod 203 are stored in a bucket 207. On an inner peripheral surface of the bucket 207, a pair of catcher slide rails 206 on which the catcher 202 slides is provided on opposing surfaces respectively. On an outer peripheral surface of the bucket 207, a catcher slide cylinder 204 which moves the catcher 202 up / down is provided in parallel with the guide rod 203, and a pair of bucket engagement pieces 210 where a bucket slide cylinder support mechanism 209 moves up / down is provided in parallel with the guide rod 203. In a bucket slide cylinder 208, a tip of the guide rod is fixed to the outer peripheral surface of the bucket 207, and a cylinder portion is fixed to the bucket slide cylinder support mechanism 209. The bucket slide cylinder support mechanism 209 is fixed to turning mechanisms 211, 212 for turning the bucket 207.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an automatic standard penetration test device and a boring machine system equipped with the same. More specifically, the entire device is compactly unitized as a single device and can be detachably attached to all boring machines from small to large, regardless of whether they are self-propelled or stationary. It can realize a smooth lifting and lowering operation with little shaking for the hammer up to a specified height. Furthermore, it relates to an automatic standard penetration test device that can automatically and efficiently perform a standard penetration test in a short time without the risk of borehole wall collapse for the test hole into which the SPT sampler is inserted, and a boring machine system equipped with the same.

Background Art

[0002] An index called "N value" is adopted as an index for quantitatively representing the hardness of the ground. The "N value" refers to the number of blows required to drive the SPT sampler 300 mm into the ground after the SPT sampler has been penetrated by its own weight or preliminary driving in a test where a hammer with a mass of 63.5 kg ± 0.5 kg is dropped onto an anvil from a height of 760 mm ± 10 mm. Note that the standard penetration test for measuring the above "N value" is defined in Japanese Industrial Standard JIS A-1219. It is stipulated that the penetration amount in preliminary driving should not exceed 150 mm from the bottom of the test hole. When setting the hammer drop height high, it is possible to complete the preliminary driving in a short time, but there is a risk of exceeding 150 mm when the ground is soft. Therefore, the skills and experience of the operator are required for preliminary driving.

[0003] Also, inventions related to standard penetration test devices for performing such standard penetration tests are known (see, for example, Patent Documents 1 to 6).

[0004] In the standard penetration test apparatus described in Patent Document 1, the hammer is configured to be vertically movable along the guide rod, and a knocking head is attached to the lower end of the guide rod. Further, a rod with a different-diameter cross-section is connected to the lower end of the knocking head, and a "boring rod" provided with a boring bit or a "test rod" provided with a sampler is selectively connected to the lower end of the rod with a different-diameter cross-section. Furthermore, a support column is installed in parallel with the guide rod, and a lifting body is attached to the support column so as to be vertically movable along the support column. A "rotating means for rotating the boring rod" is attached to the lifting body so as to be pivotable about an axis via a connecting body.

[0005] When excavating a boring hole (test hole), the rotating means is pivoted by the lifting body and disposed on the axis of the guide rod. A rod with a different-diameter cross-section to which the boring rod is connected is inserted into the rotating means, and the rotating means rotationally drives the boring rod while being struck by the hammer.

[0006] On the other hand, after excavating the boring hole, the boring rod is removed from the rod with a different-diameter cross-section, and the rotating means is lifted and pivoted by the lifting body to be retracted. Then, the test rod is connected to the rod with a different-diameter cross-section.

[0007] In the standard penetration test apparatuses described in Patent Documents 3 and 4, a rod support mechanism, a boring mechanism, and a striking mechanism are arranged at predetermined intervals in the lateral direction on the base machine, and the striking mechanism is attached to be pivotable around a pivot column.

[0008] When excavating a boring hole (test hole), the striking mechanism is retracted from the measurement position, the boring mechanism is arranged at the measurement position, and a boring rod with a boring blade attached to its tip is lifted by the rod support mechanism and set in the boring mechanism to start excavation.

[0009] On one hand, after drilling the boring hole (test hole), the holding of the drilling rod by the drilling mechanism is released, and the drilling rod is pulled up to the ground by the rod support mechanism and retracted upward. Then, a test rod with a sampler attached to its tip is installed in the boring hole (test hole), the striking mechanism is rotated and positioned at the measurement position, and the test rod will be connected to the guide rod. Then, the striking mechanism will drop the hammer freely from a specified height to strike the test rod.

[0010] By the way, regarding the hammer lifting mechanism that lifts the hammer to a specified height, in the case of the standard penetration test device described in Patent Documents 2 and 6, a rope is hung on the chuck, and the mechanism is to wind up the rope with a winch (for example, see Patent Document 2

[0011] ). Although Patent Document 1 does not have a direct description of the hammer lifting mechanism, since a pulley and a winch are depicted above the hammer's head, it is considered to be a mechanism that winds up the rope with a winch or the like.

[0011] Similarly, in the case of the standard penetration test device described in Patent Documents 3 and 4, the hammer lifting mechanism is composed of an endless chain to which the hammer chuck is fixed, a sprocket that runs the endless chain, etc. As the endless chain runs, the hammer chuck is raised and lowered along the guide rod reader. (For example, see Patent Document 3

[0013] ). That is, the hammer chuck is driven to move up and down by a guide rod reader equipped with an endless chain.

[0012] Also, in the case of the standard penetration test device described in Patent Document 6, the hammer lifting mechanism is composed of a hydraulic cylinder (for example, see Patent Document 6

[0015] ).

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

[0014] In the case described in the above patent documents, after drilling the boring hole (test hole) with a drilling rod, in order to insert the test rod with the SPT sampler into the boring hole (test hole), a process of pulling out the drilling rod from the boring hole (test hole) is separately required.

[0015] When pulling out the drilling rod from the boring hole, there is a risk that the hole wall of the boring hole (test hole) may collapse. Therefore, it had to be carefully done manually over time so as not to damage the hole wall with the cutting edge. Accordingly, a certain level of skill and experience was required of the operator, and the work load was not small.

[0016] Also, as described above, for the hammer lifting mechanism that lifts the hammer to a specified height, a lifting mechanism such as a rope winding / unwinding mechanism by a winch, an endless chain mechanism by a guide rod leader, or a hydraulic cylinder mechanism is adopted.

[0017] In any case of the hammer lifting mechanism, a column or mast for supporting the hammer lifting mechanism is required separately. In particular, in the case of a self-propelled boring machine equipped with the drilling mechanism of Patent Document 3 or 4 above, since a space for setting a swivel column for supporting the striking mechanism (guide leader) is required, the boring machine to which the hammer lifting mechanism is attached is limited to a large boring machine.

[0018] In addition, since there is mechanical play between the hammer and the guide rod, the smooth lifting and lowering by the above lifting mechanism is inhibited by this mechanical play.

[0019] Therefore, the present invention has been made in view of the problems of the above prior art, and its object is to unitize the entire device as a single device in a compact manner, and to be detachably attached to all boring machines from small to large, regardless of whether they are self-propelled or stationary types, and to realize a smooth lifting and lowering operation with little shaking of the hammer up to a specified height. Furthermore, it is to provide an automatic standard penetration test device that can automatically and efficiently perform a standard penetration test in a short time without the risk of hole wall collapse for a test hole into which an SPT sampler is inserted, and a boring machine system equipped with the same.

Means for Solving the Problems

[0020] An automatic standard penetration test apparatus according to the present invention for achieving the above object includes a hammer (201) for applying an impact force to an SPT sampler rod (1'), a gripping and dropping mechanism (202) for gripping the hammer (201) and dropping it from a specified height (760 mm), a guide rod (203) for moving the hammer (201) and the gripping and dropping mechanism (202) coaxially, a first cylinder mechanism (204) for raising and lowering the gripping and dropping mechanism (202), and a control device (300) for controlling the first cylinder mechanism (204), and is an automatic standard penetration test apparatus (200) capable of automatically performing a standard penetration test (SPT) defined by Japanese Industrial Standards (JIS). The hammer (201), the gripping and dropping mechanism (202), and the guide rod (203) are stored inside a vertically long hollow prism structure (207) so as to be movable in the vertical direction with respect to the hollow prism structure (207), and the first cylinder mechanism (204) is integrated with the hollow prism structure (207). The hollow prism structure (207) is rotatable around a predetermined rotation axis (211c, 212c) by a rotation mechanism (211, 212) and is movable in the vertical direction with respect to the rotation mechanism (211, 212).

[0021] In the above configuration, the main components (201, 202, 203) for conducting the standard penetration test (SPT) are to be stored inside the vertically long hollow prism structure (207). Therefore, the first cylinder mechanism (204) for raising and lowering the gripping and dropping mechanism (202) is arranged on the side surface, and the swivel mechanism (211, 212) can be engaged on another side surface. As a result, the entire device is compactly integrated and can be unitized as a single device. Consequently, the SPT device (200) can be rotatably attached to the existing boring device (100). Thus, when the boring device (100) is drilling, the SPT device (200) is made to wait at a standby position where it does not interfere with the drilling by the swivel mechanism (211, 212), while during the standard penetration test, it can be installed at a position (test start position) where an impact force can be applied to the SPT sampler rod (1') from a specified height (760 mm). Accordingly, it becomes possible to efficiently conduct the standard penetration test defined by JIS by utilizing the drilling function of the boring device (100).

[0022] The second feature of the automatic standard penetration test device according to the present invention is that the hollow prism structure (207) is supported so as to be vertically movable by a second cylinder mechanism (208) fixed to the swivel mechanism (211, 212), and the second cylinder mechanism (208) is supported inside a tunnel plate structure (209) with both ends open and fixed to the swivel mechanism (211, 212).

[0023] In the above configuration, by lowering the hollow prism structure (207) by the second cylinder mechanism (208), regardless of the penetration amount of the SPT sampler rod (1'), it is possible to ensure the dropping height (760 mm) of the hammer (201) inside the hollow prism structure (207) without the guide rod (203) interfering with the hollow prism structure (207).

[0024] Also, since the second cylinder mechanism (208) is stored inside the tunnel plate structure (209), it contributes to the unitization of the entire device.

[0025] The third feature of the automatic standard penetration test device according to the present invention is that the turning mechanism (211, 212) includes a third cylinder mechanism (222) for turning the hollow prism structure (207) around the turning shafts (211c, 212c).

[0026] In the above configuration, when the SPT device (200) is attached to the boring device (100), the SPT device (200) can be selectively installed either at a "standby position" that does not interfere with boring or at a "test start position" where an impact force can be applied to the SPT sampler rod (1') from a specified height (760 mm).

[0027] The fourth feature of the automatic standard penetration test device according to the present invention is that on the inner surface of the hollow prism structure (207), two pairs of vertically long first right-angle pieces (206, 206) with which the gripping and dropping mechanism (202) slidably engages are provided facing each other, and on the head of the gripping and dropping mechanism (202), two slide pieces (202i) that slidably engage with the pair of first right-angle pieces (206, 206) are provided facing each other.

[0028] In the above configuration, when the gripping and dropping mechanism (202) moves up and down, it is possible to prevent the sway of the gripping and dropping mechanism (202) from the advancing direction by the pair of first right-angle pieces (206, 206). As a result, the gripping and dropping mechanism (202) can be smoothly raised to a specified height (760 mm) at which the hammer (201) is dropped, and can be smoothly lowered to grip the hammer (201).

[0029] The fifth feature of the automatic standard penetration test device according to the present invention is that on the outer surface of the hollow prism structure (207), a pair of vertically long second right-angle pieces (210, 210) that slidably engage on both sides of the tunnel plate structure (209) are provided.

[0030] In the above configuration, when the hollow prism structure (207) moves up and down with respect to the guide rod (203), it is possible to prevent the hollow prism structure (207) from swaying in the traveling direction by the pair of second right-angled pieces (210, 210). As a result, the hollow prism frame structure (207) can be smoothly moved in the vertical direction.

[0031] A sixth feature of the automatic standard penetration test device according to the present invention is that the hollow prism structure (207) includes a first wire encoder (214) having a tip of a wire connected to a rod tip portion (205) of the first cylinder mechanism (204).

[0032] In the above configuration, it is possible to accurately measure the relative height position of the gripping and dropping mechanism (202) with respect to the hollow prism structure (207).

[0033] A seventh feature of the automatic standard penetration test device according to the present invention is that the rod tip portion of the first slider mechanism (204) is connected to the gripping and dropping mechanism (202) by a plate-shaped support mechanism (205).

[0034] In the above configuration, the sliding amount of the first cylinder mechanism (204) and the moving amount of the gripping and dropping mechanism (202) correspond one-to-one. As a result, the controllability of the automatic control for raising the hammer (201) to a specified height (760 mm) is improved.

[0035] An eighth feature of the automatic standard penetration test device according to the present invention is that a protruding piece (223) protruding laterally is fixed to the STP sampler rod (1'), and the tunnel plate structure (209) supports a second wire encoder (215) "having a tip of a wire connected to the protruding piece (223)".

[0036] In the above configuration, it is possible to fix the tip of the wire in the direction vertically downward from the second wire encoder (215). As a result, it is possible to accurately measure the penetration amount of the SPT sampler rod (1') into the ground.

[0037] The ninth feature of the automatic standard penetration test device according to the present invention is that the gripping and dropping mechanism (202) has a hammer detection sensor (219) for detecting the hammer (201).

[0038] In the above configuration, when the hammer detection sensor (219) switches from the state of "detecting the hammer (201)" to the state of "not detecting the hammer (201)", it can be regarded that the hammer (201) has freely fallen and struck the SPT sampler rod (1'), so that the number of strikes can be counted by the hammer detection sensor (219).

[0039] The tenth feature of the automatic standard penetration test device according to the present invention is that the hollow prism structure (207) is provided with a target (227) indicating a reference height position of the hollow prism structure (207) so as not to interfere with the top of the guide rod (203) (213), and the tunnel plate structure (209) supports a target detection sensor (218) for "detecting the target (227)".

[0040] In the above configuration, it is possible to automatically lower the hollow prism structure (207) to a height position that does not interfere with the top of the guide rod (203) (213).

[0041] The eleventh feature of the automatic standard penetration test device according to the present invention is that the control device (300) calculates the average value of the "penetration amount per drop height" for the hammer drop height, and based on the average value of the "penetration amount per drop height", estimates the "next hammer drop height (mm)" required to penetrate the "remaining distance for preliminary driving (mm)" by one strike, and when the estimated "next hammer drop height (mm)" exceeds a predetermined upper limit value (760 mm), sets it to the upper limit value (760 mm), so as to ensure that the cumulative penetration amount during preliminary driving does not exceed the specified penetration amount (150 mm).

[0042] With the above configuration, it is possible to end the "preliminary driving" so that the "cumulative penetration amount during preliminary driving" does not exceed the specified penetration amount (150 mm) with the minimum necessary number of blows.

[0043] The twelfth feature of the automatic standard penetration test device according to the present invention is that the control device (300) sets a plurality of stepped heights (50 mm, 100 mm, 200 mm) lower than the specified height (760 mm) for the hammer drop height, and increases or decreases the next hammer drop height stepwise according to the penetration amount of the SPT sampler rod (1') per the previous single blow. When the remaining distance (mm) of the preliminary driving becomes less than or equal to the penetration amount (mm) per the previous single blow, the next hammer drop height is decreased step by step so that the cumulative penetration amount during the preliminary driving does not exceed the specified penetration amount (150 mm).

[0044] With the above configuration, it is possible to increase or decrease the hammer drop height step by step while checking the penetration amount per single blow so that the cumulative penetration amount of the SPT sampler rod (1') does not exceed the specified penetration amount.

[0045] The boring machine system according to the present invention for achieving the above object is an automatic standard penetration test device (200) having all or part of the above-described first to eleventh features, a boring rod (1) with an open tip for boring the ground, an upper part (2a) locked to the inner peripheral surface of the boring rod (1), and a core barrel (2) consisting of "a hollow cylindrical lower part (2b) that is rotatable relative to the upper part (2a) and has an open end", an overshot (3) for recovering the core barrel (2), a feeding device (30) for feeding the boring rod (1) in a predetermined direction, a rotational drive device (40) for rotating the boring rod (1), a water supply device (50) for supplying boring water to the boring rod (1), a lifting device (34, 35) for lifting the core barrel (2) to the ground, a first clamping mechanism (31) capable of gripping the SPT sampler rod (1'), and a second clamping mechanism (32) capable of gripping the boring rod (1). In the boring machine system (100), the automatic standard penetration test device (200) is rotatably attached to the feeding device (30) or a fixing member, and the test hole for inserting the SPT sampler rod (1') is configured to be bored by a core barrel assembly in which the core barrel (2) is mounted on the inner peripheral surface of the boring rod (1).

[0046] In the above configuration, a test hole reaching the test target section from the ground surface is bored by a core barrel assembly (wire line method), and then the core barrel (2) is recovered by the overshot (3). Thus, the boring rod (1) remaining in the ground can be used as a test hole for inserting the SPT sampler rod (1'). That is, as a post-treatment after boring, it is not necessary to lift the boring rod (1) to the ground. Further, since the hole wall of the test hole is protected by the boring rod (1), the risk of hole wall collapse is eliminated.

[0047] A second feature of the boring machine system according to the present invention is that the first clamping mechanism (31) is attachable / detachable with a sub-chuck (228) that enables gripping of the SPT sampler rod (1').

[0048] In the above configuration, it is possible to selectively perform hole drilling by means of core barrel assembly (wire line method) and standard penetration test (SPT).

Advantages of the Invention

[0049] According to the automatic standard penetration test device of the present invention, the entire device is compactly unitized as a single device, and can be detachably attached to all types of boring machines from small to large, regardless of whether they are self-propelled or stationary. Moreover, it is possible to realize a smooth lifting and lowering operation with little shaking for the catcher holding the hammer up to a specified height.

[0050] In addition, according to the boring machine system of the present invention, it becomes possible to automatically and efficiently perform the standard penetration test in a short time for the test hole into which the SPT sampler is inserted without the risk of hole wall collapse.

Brief Description of the Drawings

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Modes for Carrying Out the Invention

[0052] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0053] FIGS. 1 and 2 are explanatory views showing a boring device 100 to which a striking device 200 according to the present invention is rotatably attached. FIG. 1 represents a front view of the boring device 100 in a state where both the swivel head 40 and the striking device 200 are arranged at the standby positions. FIG. 2 represents a left side view of FIG. 1. For convenience of explanation, in FIG. 2, the striking device 200 is arranged at the test start position.

[0054] This boring device 100 excavates a test hole for inserting an SPT sampler rod 1' to a predetermined depth by a core barrel assembly (boring rod 1 + core barrel 2), and then only the core barrel 2 is recovered by an overshot 3, leaving the boring rod 1 as the test hole. The SPT sampler rod 1' is inserted into the boring rod 1, and subsequently, a standard penetration test (JIS A 1219) for measuring the N value can be automatically performed.

[0055] As shown in FIG. 26, the above-mentioned "core barrel assembly" means a so-called sleeve-type triple tube composed of an "outer tube part" (boring rod 1) that rotates integrally with a casing rod (not shown) having openings at both ends and a boring blade (bit) at the tip, and an "inner tube part" (core barrel 2) having a space for accommodating the core, where the lower part 2b is rotatable relative to the head part 2a while the head part 2a is locked to the inner peripheral surface of the outer tube part.

[0056] Further, the striking device 200 is compactly unitized as a single device, and is detachably and rotatably attached to the leader device 30 of the boring device 100 without the need for a dedicated support column. The striking device 200 realizes a smooth lifting and lowering operation with little shaking up to a specified height for the upward movement of the catcher 202 (FIG. 3) holding the hammer 201 (FIG. 3) and the downward movement of the catcher 202 (FIG. 3) alone. Details of this striking device 200 will be described later with reference to FIGS. 3 to 10.

[0057] As shown in FIG. 1, the mechanical configuration of the boring device 100 includes a crawler device 10 for moving the vehicle body 20 forward and backward, a vehicle body 20 in which a power chamber for housing an internal combustion engine, a hydraulic pump, and their control devices is arranged, a leader device (feed device) 30 for raising and lowering a swivel head (rotary drive device) 40, a swivel head (rotary drive device) 40 for applying a rotational torque to a boring rod 1, a water supply pump 50 (FIG. 2) for supplying boring water to the boring rod 1, and a striking device 200 for conducting a standard penetration test. Incidentally, taking an example of the dimensions and weight of the boring device 100, the overall width is 1200 mm, which is shorter than the standard of a light motor vehicle, the overall length during transportation is 3870 mm, which is shorter than the standard of a normal passenger car, and the overall height during transportation is also 2220 mm, which is shorter than the standard of a normal passenger car. Also, the weight is, for example, 3.1 tons. Therefore, the boring device 100 can be loaded onto a transport vehicle in the 4-ton class. Hereinafter, each configuration will be described.

[0058] As shown in FIG. 2, the crawler device 10 has left and right independent traveling motors (not shown), left and right independent drive wheels 11, 11 directly connected to each traveling motor, left and right independent idler wheels 12, 12 that can rotate, left and right independent endless tracks 13, 13 wound between the drive wheels 11 and the idler wheels 12, and a plurality of rotatable left and right independent roller wheels 14 arranged between the drive wheels 11 and the idler wheels 12 to hold the tension of the endless track 13, and moves the vehicle body 20 forward, backward, and left and right.

[0059] In addition to the above power chamber, the vehicle body 20 is separately provided with a leader tilting mechanism 24 for raising or tilting a leader body 33, a leader sliding mechanism 25 for sliding the leader body 33 up and down, and a swivel motor (not shown) for swiveling the vehicle body 20 around the vertical direction.

[0060] The leader device 30 includes a first clamping mechanism 31 for clamping the SPT sampler rod 1', a second clamping mechanism 32 for clamping the boring rod 1, a leader body 33 that serves as a moving rail for the swivel head 40 to move up and down along the vertical direction, a sheave 34 for lifting the boring rod 1 or the STP sampler rod 1', and a winch 35 for winding up the wire.

[0061] In particular, the outer diameter of the boring rod 1 is about 88 mm, while the outer diameter of the SPT sampler rod 1' is about 51 mm. In the normal state, the first clamping mechanism 31 cannot grip the SPT sampler rod 1'. Therefore, a sub-chuck 228 (Fig. 27) is attached to the first clamping mechanism 31 so that the first clamping mechanism 31 can grip the SPT sampler rod 1'.

[0062] Also, the leader body 33 is provided with a hydraulic cylinder 36 (Fig. 1) for moving the swivel head 40 up and down. The hydraulic cylinder 36 is provided in a vertical groove 33a formed along the central longitudinal direction of the leader body 33. Therefore, it is possible to push down the boring rod 1 driven to rotate by the swivel head 40 into the ground or pull it up from the ground by the hydraulic cylinder 36.

[0063] The leader device 30 also includes a head slide mechanism 37 for sliding the swivel head 40 in the left-right direction (lateral direction) and a mast slide mechanism 38 for sliding the sheave 34 up and down.

[0064] The swivel head 40 includes a head end 41 for connecting the boring rod 1, a rotary motor 42 for generating rotational torque, a head rotating part 43 for rotating the head end 41, and a spindle 44 for transmitting the rotational torque of the rotary motor 42 to the head rotating part end 43.

[0065] FIG. 3 is an explanatory view showing the mechanism part of the striking device 200 according to the present invention. For convenience of explanation, some parts such as the bucket 207 are drawn as semi-transparent figures so that the internal mechanism can be understood. Further, the sensor part attached to the striking device 200 will be described later with reference to FIGS. 6 and 7.

[0066] This striking device 200 is rotatably attached to the leader main body 33 (FIG. 2) via two turning mechanisms 211, 212. The striking device 200 is rotated around the rotation axes 211c, 212c by a swing cylinder 222 (FIG. 7) and is selectively positioned at either the "standby position" or the "test start position".

[0067] In the "standby position", the striking device 200 does not interfere with the rotation of the swivel head 40 and the elevation of the leader device 30. On the other hand, in the "test start position", the striking device 200 is positioned on the axis of the SPT sampler rod 1' and the hammer 201 can apply an impact from a specified height to the anvil 224.

[0068] As the configuration of the striking device 200, there are a hammer 201 that applies an impact to the SPT sampler rod 1', a catcher 202 that holds the hammer 201 at a specified height and allows it to fall freely, a guide rod 203 that moves the hammer 201 and the catcher 202 coaxially, a catcher slide cylinder 204 that raises and lowers the catcher 202 along the guide rod 203, a catcher support mechanism 205 that integrates the catcher slide cylinder 204 and the catcher 202, four catcher slide rails 206 on which the catcher 202 slides, a bucket 207 with a hollow square column frame structure that houses the "hammer 201, catcher 202, and guide rod 203", a bucket slide cylinder 208 whose rod is integrated with the bucket 207 and moves the bucket 207 in the vertical direction, a bucket slide cylinder support mechanism 209 that supports the cylinder part of the bucket slide cylinder 208, four bucket engaging pieces 210 that are fixed to the corners of the outer surface of the bucket 207 and engage and slide on both sides of the bucket slide cylinder support mechanism 209, a first turning mechanism 211 that turns the bucket 207 around the first turning axis 211c, a second turning mechanism 212 that turns the bucket 207 around the second turning axis 212c, and a rod locking part 213 that locks the guide rod 203 to the upper surface of the bucket 207. Hereinafter, each configuration will be further described.

[0069] The hammer 201 has a shape conforming to JIS A1219.

[0070] The catcher 202 is configured to release (release) the hammer 201 by hydraulic pressure and hold the hammer 201 by releasing the hydraulic pressure. Details of the catcher 202 will be described later with reference to FIGS. 4 and 5.

[0071] The guide rod 203 has the hammer 201 and the catcher 202 inserted therethrough, with a rod locking part 213 connected to the upper end, and the SPT sampler rod 1' connected to the lower end via an anvil 224 (FIG. 8).

[0072] The catcher slide cylinder 204 is fixed to the bucket 207 by a fastener (screw) parallel to the guide rod 203.

[0073] The catcher support mechanism 205 has a vertically long plate structure. The catcher slide cylinder 204 is connected to the upper vertical part thereof, and the catcher 202 is connected to the lower vertical part thereof via a connecting piece 202j (Fig. 4).

[0074] The catcher slide rail 206 has an L-shaped cross-sectional shape and a vertically long prism structure. Two catcher slide rails 206 are provided as a set, and two sets of catcher slide rails 206 are fixed to the inner surface of the bucket 207 by fasteners (screws) in a facing manner. Two slide pieces 202i (Fig. 4) that slide on the two sets of catcher slide rails 206 are attached to the head of the catcher 202. When the catcher 202 moves up and down along the guide rod 203 by the two sets of catcher slide rails 206, the swing of the catcher 202 due to mechanical play is suppressed, and the up and down movement of the catcher 202 becomes smooth.

[0075] The bucket 207 has a vertically long hollow square prism frame structure (box-shaped structure). Through holes (not shown) through which the guide rod 203 penetrates are provided on the upper and lower surfaces of the bucket 207, respectively. A bucket engaging piece 210 (four in this embodiment), a catcher slide cylinder 204, the rod tip of the bucket slide cylinder 208, and a first wire encoder (Fig. 6) for measuring the movement amount of the catcher 202 are attached to the outer surface of the bucket 207, respectively.

[0076] The bucket slide cylinder 208 has a rod tip fixed to the outer surface of the bucket 207 and a cylinder portion fixed to the bucket slide cylinder support mechanism 209. The bucket slide cylinder support mechanism 209 is fixed to the first turning mechanism 211 and the second turning mechanism 212. The packet slide cylinder 208 causes the packet 207 to move relative to the first turning mechanism 211 and the second turning mechanism 212.

[0077] The bucket engaging piece 210 has an L-shaped cross-sectional shape and forms a vertically long prism structure, and is attached to a corner portion of the outer surface of the bucket 207. The bucket engaging piece 210 engages with a side portion of the bucket slide cylinder support mechanism 209 and restricts the lateral swing of the bucket 207 when the bucket 207 moves up and down. As a result, the bucket 207 can be smoothly moved up and down.

[0078] The first turning mechanism 211 includes a fixed portion 211a, a turning portion 211b, and a turning shaft 211c that rotatably connects the fixed portion 211a and the turning portion 211b. The fixed portion 211a is fixed to the leader main body 33 (FIG. 2). The turning portion 211b is fixed to the bucket slide cylinder support mechanism 209. The cylinder portion of a bucket swing cylinder (FIG. 7) is connected to the fixed portion 211a, and the rod tip is connected to the turning portion 211b. Therefore, when the bucket swing cylinder (FIG. 7) contracts, the turning portion 211b turns to the standby position, and when the bucket swing cylinder extends, the turning portion 211b turns to the test start position.

[0079] The second turning mechanism 212, similar to the first turning mechanism 211, includes a fixed portion 211a, a turning portion 211b, and a turning shaft 211c that rotatably connects the fixed portion 211a and the turning portion 211b. The fixed portion 211a is fixed to the leader main body 33 (FIG. 2). The turning portion 211b is fixed to the bucket slide cylinder support mechanism 209.

[0080] The rod locking portion 213 is attached to the tip of the guide rod 203 to prevent the guide rod 203 from falling off the bucket 207.

[0081] Figures 4 and 5 are explanatory diagrams showing the cross-section of the main part of the catcher 202 according to the present invention. Figure 4 shows the state where the catcher 202 holds the hammer 201, and Figure 5 shows the state where the catcher 202 releases the hammer 201.

[0082] As shown in Figure 4, the mechanical structure of the catcher 202 includes a cylindrical portion 202a with both ends open, a fixed sleeve 202b through which the guide rod 203 is inserted and seals the larger opening of the cylindrical portion 202a, a movable sleeve 202c arranged concentrically with the fixed sleeve 202b and slidable on the outer peripheral surface of the fixed sleeve 202b, a return spring 202d that biases the movable sleeve 202c in the direction to return it to the initial position, a cam 202e that drives the catcher claw 202f to open, a catcher claw 202f that engages with the head step portion 201a of the hammer 201, a closing biasing spring 202g that biases the catcher claw 202f in the closing direction, a casing 202h that houses the catcher claw 202f and the closing biasing spring 202g, a slide piece 202i that slides on the catcher slide rail 206 (Figure 3), a connecting piece 202j that connects to the catcher support mechanism 205, and an O-ring 202k that prevents the leakage of hydraulic oil.

[0083] As shown in Figure 5, the space surrounded by the cylindrical portion 202a, the fixed sleeve 202b, and the movable sleeve 202c forms a variable-volume oil chamber. When hydraulic oil flows into the oil chamber, the movable sleeve 202c is moved downward against the return spring 202d by the hydraulic pressure, the cam 202e engages with the catcher claw 202f, and the catcher claw 202f is pushed open against the closing biasing spring 202g. As a result, the engagement between the catcher claw 202f and the head step portion 201a is released, and the hammer 201 falls freely.

[0084] Conversely, when the hydraulic oil flows out from the oil chamber, the movable sleeve 202c is moved upward by the return spring 202d, the engagement of the cam 202e with the catcher claw gradually weakens, and finally the engagement of the cam 202e with the catcher claw 202f disappears. As a result, the catcher claw 202 is closed by the closing biasing spring 202g and engages with the head step portion 201a of the hammer 201.

[0085] The oil chamber is sealed by three O-rings 202k.

[0086] The cam 202e is fixed to the tip of the movable sleeve 202c by a fastener.

[0087] When the catcher 202 holds the hammer 201, there is play between the catcher 202 and the hammer 201.

[0088] Figures 6 and 7 are explanatory diagrams showing the mounting positions of the sensors for the striking device 200. Figure 6 shows the mounting positions of the first wire encoder 214 for measuring the height of the catcher 202 and the second wire encoder 215 for measuring the penetration amount of the SPT sampler rod 1', respectively. Figure 7 shows the mounting positions of the first magnetic switch 216 and the second magnetic switch 217 of the swing cylinder 222, respectively.

[0089] As shown in Figure 6, the first wire encoder 214 for measuring the height of the catcher 202 is fixed to the outer surface of the bucket 207. The wire of the first wire encoder 214 is attached to the catcher support mechanism 205.

[0090] On the other hand, the second wire encoder 215 for measuring the penetration amount of the SPT sampler rod 1' is not fixed to the outer surface of the bucket 207 and is fixed to the first turning mechanism 211 via a connecting member 226 (Figure 7).

[0091] Also, on the upper part of the second wire encoder 215, a first proximity sensor 218 for detecting the height position (target 227) of the bucket 207 so that the bucket 207 does not interfere with the rod locking portion 213 of the guide rod 203 is fixed. Further, a target 227 that reacts to the first proximity sensor 218 is fixed to the side of the bucket 207 facing the first proximity sensor 218.

[0092] As shown in FIG. 7, for the swing cylinder 222 that swings the bucket 207 to either the "standby position" or the "test start position", a magnet is embedded in the piston (not shown). The first magnetic switch 216 detects the position where the piston is displaced maximally to the right side in the drawing. The position where the piston is displaced maximally to the right side in the drawing corresponds to the "test start position" of the bucket 207.

[0093] On the other hand, the second magnetic switch 217 detects the position where the piston is displaced maximally to the left side in the drawing. The position where the piston is displaced maximally to the left side in the drawing corresponds to the "standby position" of the bucket 207.

[0094] Regarding the bucket slide cylinder 208 that changes the height position of the bucket 207, a magnet is also embedded in the piston (not shown). The third magnetic switch 220 (not shown) detects the position where the piston is displaced maximally upward in the drawing. On the other hand, the fourth magnetic switch 221 (not shown) detects the position where the piston is displaced maximally downward in the drawing. Note that the third magnetic switch 220 and the fourth magnetic switch 221 are attached to the cylinder of the bucket slide cylinder 208.

[0095] FIG. 8 is an explanatory diagram showing the penetration measurement jig 223. The penetration measurement jig 223 has a shape that protrudes horizontally from the lower coupling 225L of the anvil 224 and bends upward. Regarding the configuration of the penetration measurement jig 223, it is composed of a left half ring piece 223a, a right half ring piece 223b that tightens the lower coupling 225L together with the left half ring piece 223a, an L-shaped piece 223c for hanging the wire vertically downward, a U-shaped piece 223d for locking the wire, and a female screw piece 223e for fixing a bolt that penetrates the U-shaped piece 223d.

[0096] The left half ring piece 223a and the right half ring piece 223b fasten the lower coupling 225L with two sets of bolts and nuts, so that the penetration measurement jig 223 is fixed to the lower coupling 225L.

[0097] The wire hanging from the second wire encoder 215 is fixed to the penetration measurement jig 223 by locking the through hole of the hook to the bolt.

[0098] Figure 9 is a perspective explanatory diagram showing the catcher 202. A second proximity sensor 219 for detecting the hammer 201 is attached to the lower surface of the casing 202h of the catcher 202.

[0099] Figure 10 is a block diagram showing the configuration of the SPT control unit 300 of the striking device 200. This SPT control unit 300 includes a management monitor unit 310 for the operator to set and monitor various operating conditions related to the standard penetration test, a control unit 320 for controlling the corresponding cylinders 204, 208, 222 based on the various operating conditions set by the operator, and an SPT remote control 330 for the operator to remotely operate the standard penetration test. The following describes each configuration.

[0100] The management monitor unit 310 can be configured by, for example, a tablet-type portable terminal device, a storage-type terminal device, or an embedded-type terminal device that can be attached to the vehicle body 20. Details of the management monitor unit 310 will be described later with reference to FIG. 11.

[0101] The control unit 320 can be configured by a control device such as a PLC (= Programmable Logic Controller). The control unit 320 is wired-connected to a first wire encoder 214 that measures the height of the catcher 202, a second wire encoder 215 that measures the penetration amount of the SPT sampler rod 1', a first magnetic switch 216 that detects the extension of the swing cylinder 222, a second magnetic switch 217 that detects the contraction of the swing cylinder 222, a first proximity sensor 218 that detects the "testable position" of the packet 207, a second proximity sensor 219 that detects the "grabbing position" of the hammer 201 by the catcher 202, a third magnetic switch 220 that detects the upper limit position of the bucket 207, and a fourth magnetic switch 221 that detects the lower limit position of the bucket 207.

[0102] The control unit 320 is configured to be able to perform a standard penetration test defined by Japanese Industrial Standards in automatic mode by operating a hydraulic control valve 222a for the swing cylinder, a hydraulic control valve 204a for the catcher slide cylinder, or a hydraulic control valve 208a for the bucket slide cylinder based on the above sensor information. This automatic mode will be described later with reference to FIGS. 12 to 16.

[0103] The SPT remote controller 330 transmits a command to the control unit 320 via a wire. In this embodiment, the SPT remote controller 330 and the control unit 320 are connected by a wire, but they can also be connected wirelessly such as by Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0104] FIG. 11 is an explanatory diagram showing the management monitor unit 310 of the SPT control unit 300. "Boring Depth (m)" indicates the final depth at which boring was performed. "Number of Blows" indicates the cumulative number of blows from the start to the end of the test. "Penetration per Blow (mm)" indicates the amount of penetration with each blow. "Cumulative Penetration (mm)" indicates the amount of penetration from the start to the end of the test. "Rod Self-Settlement (mm)" indicates the amount of penetration during rod self-settlement. "Hammer Self-Settlement (mm)" indicates the amount of penetration during hammer self-settlement. "Pre-Strike Number of Blows" indicates the number of blows during the pre-strike period. "Total Penetration" indicates the amount of penetration from self-settlement to pre-strike.

[0105] "0 - 100mm" indicates the number of blows and the amount of penetration during the "0 - 100m" section of the main strike. "100 - 200mm" indicates the number of blows and the amount of penetration during the "100 - 200mm" section of the main strike. "200 - 300mm" indicates the number of blows and the amount of penetration during the "200 - 300mm" section of the main strike. "Total Penetration" indicates the number of blows and the amount of penetration during the main strike section.

[0106] In the "Operation Display", for the first clamp mechanism 31, it indicates whether it is in the open state (open state) or the gripping state (closed state). For the bucket 207, it indicates whether it has risen or fallen. For the catcher 202, it indicates whether it has risen or fallen to the specified height. For the catcher claw 202f, it indicates whether it is in the closed state or the open state. For the height of the catcher 202, it indicates the measured value (mm) by the first wire encoder 214.

[0107] Figures 12 to 16 are flowcharts showing the automatic control of the standard penetration test by the SPT control unit 300. The shaded part represents manual operation. Also, Figures 18 to 25 are explanatory diagrams showing the respective operations of the boring device 100 or the striking device 200 corresponding to each flow. For convenience of explanation, the hollow casing rod connected to the boring rod 1 for extending the axial length is not shown in the illustration.

[0108] As shown in step S0 of FIG. 12, first, preparations for the standard penetration test are carried out.

[0109] Regarding the preparations, as shown in FIG. 18, first, a test hole TH is drilled by a core barrel assembly (drilling rod 1 + core barrel 2). After the drilling of the test hole TH is completed, an overshot 3 is dropped inside the drilling rod 1 to recover the core barrel 2 inside the hole. In this case, the lifting dog (FIG. 26) of the overshot 3 fits into the spear head (FIG. 26) of the core barrel 2, and the overshot 3 and the core barrel 2 are connected.

[0110] Next, the overshot 3 is pulled up by the winch 35 to recover the core barrel 2. As a result, a test hole TH with a predetermined depth (1 m in this embodiment) is formed, where the hole wall (the inner peripheral surface of the test hole TH) is protected by the drilling rod 1 and there is no risk of hole wall collapse.

[0111] Next, in order to grip the SPT sampler rod 1' with the first clamping mechanism 31, a sub-chuck 228 is attached to the first clamping mechanism 31. Then, while suspending the SPT sampler rod 1' by the wire WL, it is placed statically at the bottom of the test hole TH through the opening of the sub-chuck 228. Then, the first clamping mechanism 31 is closed to fix the SPT sampler rod 1' by the first clamping mechanism 31.

[0112] Next, as shown in FIG. 19, the wire WL is removed from the SPT sampler rod 1'. Then, the bucket 207 is raised by +600 mm. This bucket height position corresponds to the uppermost extended position of the bucket slide cylinder 208 (the position detected by the third magnetic switch 220). Next, the swing cylinder 222 is driven in the extending direction to swing the packet 207 to the "test start position". The guide rod 203 is arranged on the axis of the SPT sampler rod 1'.

[0113] As shown in item 9 of FIG. 20, an in - penetration amount measuring jig 223 is attached to the SPT sampler rod 1'. The hook of the wire of the second wire encoder 215 (FIG. 8) is locked to the U - shaped piece part 223d (FIG. 8) of the in - penetration amount measuring jig 223. The above is the test preparation process.

[0114] Returning to FIG. 12, in step S1, press the test start button. The test start button is installed on the SPT remote controller 330 (FIG. 10).

[0115] Next, in step S2, open the first clamp mechanism 31.

[0116] Next, in step S3, rod self - settlement is measured by the second wire encoder 215. This step S3 and the above step S2 correspond to item 10 of FIG. 20.

[0117] Next, in step S4, it is determined whether the in - penetration amount in 0.3 seconds is 3 mm or less. If the in - penetration amount in 0.3 seconds is 3 mm or less (YES), step S5 is executed. On the other hand, if the in - penetration amount in 0.3 seconds exceeds 3 mm (NO), the rod self - settlement measurement is continued. Note that the reference value (the above 3 mm) of the in - penetration amount per a predetermined time (the above 0.3 seconds) can be appropriately changed in the management monitor unit 310 (FIG. 11).

[0118] Next, in step S5, the rod self - settlement measurement by the second wire encoder 215 is terminated.

[0119] Next, in step S6, the first clamp mechanism 31 is closed to fix the SPT sampler rod 1' so that the SPT sampler rod 1' cannot be pushed down by the weights of the hammer 201, the catcher 2, and the anvil 224.

[0120] Next, in step S7, it is determined whether or not the penetration amount is less than 450 mm from the bottom of the test hole. If the penetration amount is less than 450 mm from the bottom of the test hole (YES), step S8 is executed. On the other hand, if the penetration amount exceeds 450 mm from the bottom of the test hole (NO), the standard penetration test is terminated. This "450 mm" penetration amount means the total value of the upper limit value (150 mm) of the penetration amount in "pre-drilling" and the upper limit value (300 mm) of the penetration amount in "main drilling".

[0121] Next, in step S8, the bucket 207 is lowered by 100 mm, and the anvil 224 and the SPT sampler rod 1' are connected. This step S8 corresponds to item 11 in FIG. 20.

[0122] The anvil 224 is pre-connected to the lower end of the guide rod 203 by an upper coupling 225U (FIG. 8). The anvil 224 and the SPT sampler rod 1' are connected by a lower coupling 225L (FIG. 8). Note that a through hole (not shown) through which the guide rod 203 and the anvil 224 can pass is formed at the bottom of the bucket 207. The hammer 201 is configured not to be able to pass through the through hole.

[0123] Next, in step S9, the standard penetration test is resumed. The standard penetration test is resumed by pressing the test start button on the SPT remote controller 330 (FIG. 10).

[0124] Next, in step S10, a bucket avoidance position is selected. The "bucket avoidance position" means the height position of the bucket 207 at which the bucket 207 does not interfere with the moving parts (the catcher 202 and the guide rod 203) through the hammer self-sinking → pre-drilling → main drilling. In the present embodiment, two (the "initial bucket avoidance position" and the "lower bucket avoidance position") are prepared as the bucket avoidance positions. The following is the process for determining which of the two to adopt.

[0125] Next, in step S11, it is determined whether the penetration amount due to the self-sinking of the rod is less than 80 mm from the bottom of the test hole. If the penetration amount due to the self-sinking of the rod is less than 80 mm from the bottom of the test hole (YES), step S12-1 is executed. On the other hand, if the penetration amount due to the self-sinking of the rod exceeds 80 mm from the bottom of the test hole (NO), step S12-2 is executed.

[0126] In step S12-1, the catcher 202 is raised. The rising distance is the value obtained by subtracting the "penetration amount due to the self-sinking of the rod" from "400 mm". The catcher 202 holds the hammer 201.

[0127] In step S13-1, the bucket 207 is lowered. The lowering position is the position where the first proximity sensor 218 detects the target 207 fixed to the bucket 207 (hereinafter referred to as the "initial bucket avoidance position"). This step S13-1 corresponds to item 12 in FIG. 21.

[0128] On the other hand, in step S12-2, the catcher 202 is raised. The rising distance is the value obtained by subtracting the "penetration amount due to the self-sinking of the rod" from "500 mm". The catcher 202 holds the hammer 201.

[0129] In step S13-2, the bucket 207 is lowered. The lowering position is the lowest end position where the bucket slide cylinder 208 is most contracted (the position detected by the fourth magnetic switch 221). The above position will be hereinafter referred to as the "lower bucket avoidance position".

[0130] In step S14, the catcher 202 is released. In this case, although the self-weight of the hammer 201 is loaded on the anvil 224, since the SPT sampler rod 1' is held and fixed by the first clamping mechanism 31, the self-weight of the hammer 201 is not loaded on the SPT sampler rod 1'.

[0131] In step S15, the catcher 202 is raised by 800 m. The reason for raising it by 800 m is to consider the mechanical play (slack) between the hammer 201 and the catcher 202 in addition to the lifting height (760 mm) of the hammer 201.

[0132] In step S16, the selection of the bucket avoidance position is completed.

[0133] In step S17, the first clamp mechanism 31 is opened.

[0134] In step S18, the self-sinking of the hammer is measured. In this case, in addition to the hammer 201, the weight of the guide rod 203 is also loaded on the SPT sampler rod 1'. This step S18 and the above step S17 correspond to item 13 in FIG. 21.

[0135] In step S19, it is determined whether the penetration amount in 0.3 seconds is 3 mm or less. If the penetration amount in 0.3 seconds is 3 mm or less (YES), step S20-1 is executed. On the other hand, if the penetration amount in 0.3 seconds exceeds 3 mm (NO), step S20-2 is executed.

[0136] In step S20-1, it is determined whether the bucket 207 is stopped. If the bucket 207 is stopped (YES), step S21-1 (measurement end of the self-sinking of the hammer) is executed. On the other hand, if the bucket 207 is not stopped (NO), step S21-2 is executed.

[0137] In step S21-2, the bucket 207 is lowered to the "lower end position for bucket avoidance" and returns to step S18 (measurement of the self-sinking of the hammer).

[0138] In step S20-2, it is determined whether the penetration amount is 80 mm or more from the bottom of the test hole. If the penetration amount is 80 mm or more from the bottom of the test hole (YES), it proceeds to step S21-2 and the bucket 207 is lowered to the "lower end position for bucket avoidance". On the other hand, if the penetration amount is less than 80 mm from the bottom of the test hole (NO), it returns to step S18 (measurement of the self-sinking of the hammer).

[0139] In step S22, it is determined whether the total penetration amount including the hammer self-sinking is less than 450 mm from the bottom of the test hole. If the total penetration amount including the hammer self-sinking is less than 450 mm from the bottom of the test hole (YES), step S22 is executed. On the other hand, if the penetration amount due to the hammer self-sinking is 450 mm or more from the bottom of the test hole (NO), the standard penetration test is terminated.

[0140] In step S23, it is determined whether the total penetration amount including the hammer self-sinking is less than 150 mm from the bottom of the test hole. If the total penetration amount including the hammer self-sinking is less than 150 mm from the bottom of the test hole (YES), step S24 is executed. On the other hand, if the penetration amount due to the hammer self-sinking is 150 mm or more from the bottom of the test hole (NO), "main driving" is started.

[0141] In step S24, "preliminary driving" is started. This corresponds to item 14 in FIG. 21 and item 15 in FIG. 22.

[0142] In step S25, the hammer drop height is set in one step. When the hammer drop height is the specified height (760 mm) and the target section of the standard penetration test is soft ground, the penetration amount (mm) per blow becomes large, and there is a risk that the cumulative penetration amount in the preliminary driving exceeds the specified penetration amount (150 mm). Therefore, regarding the hammer drop height, while gradually changing the hammer drop height step by step from the lowest step, the cumulative penetration amount (mm) in the preliminary driving is made not to exceed the specified penetration amount (150 mm). Note that the next hammer drop height is determined based on the penetration amount (mm) of the immediately preceding blow and the remaining distance of the preliminary driving (= 150 mm - current cumulative penetration amount). This will be described with reference to FIG. 17.

[0143] Figure 17 is an explanatory diagram showing the light striking operation process during preliminary striking. Figure 17(a) shows the calculation of the next hammer drop height based on the "remaining distance of preliminary striking (mm)" and the "penetration amount per drop height". The vertical axis shows both the "cumulative penetration amount (mm)" and the "remaining distance of preliminary striking (mm)", and the horizontal axis represents the number of strikes (number of times). Therefore, the black circles indicate the "cumulative penetration amount (mm)" and the "remaining distance of preliminary striking (mm)" immediately after the strike, and the vertical difference between adjacent black circles represents the "penetration amount per strike (mm)".

[0144] Figure 17(b) shows the transition of the hammer drop height stages at each number of strikes (number of times). The light striking operation process during preliminary striking is calculated by dividing the "remaining distance of preliminary striking (mm)" by the "penetration amount per drop height". When the next hammer drop height exceeds 760 mm (upper limit value), the next hammer drop height is set to 760 mm. Hereinafter, it will be described in detail with reference to the drawings.

[0145] As shown in Figure 17(b), the hammer drop height at the first preliminary strike is set to be the lowest stage of "50 mm". As shown in Figure 17(a), the penetration amount at the first preliminary strike is "5 mm", and the "penetration amount per drop height" is 0.1 (= 5 mm ÷ 50 mm). Also, the "remaining distance of preliminary striking (mm)" after the first preliminary strike is "145 mm". Therefore, the hammer drop height at the second preliminary strike is "1450 mm" (= 145 mm ÷ 0.1).

[0146] However, since this "1450 mm" exceeds "760 mm", the next hammer drop height is "760 mm".

[0147] Subsequently, the penetration amount of the second preliminary strike is "80 mm", and the "penetration amount per drop height" is 0.105 (= 80 mm ÷ 760 mm). Therefore, the "average value of the penetration amount per drop height" for the first and second preliminary strikes is 0.103 (= (0.1 + 0.105) ÷ 2). Also, the "remaining distance of the preliminary strike (mm)" after the second preliminary strike is "65 mm". Thus, the hammer drop height for the third preliminary strike is "631 mm" (= 65 mm ÷ 0.103).

[0148] Subsequently, the penetration amount of the third preliminary strike is "55 mm", and the "penetration amount per drop height" is 0.087 (= 55 mm ÷ 631 mm). Therefore, the "average value of the penetration amount per drop height" from the first to the third preliminary strikes is 0.097 (= (0.1 + 0.105 + 0.087) ÷ 3). Also, the "remaining distance of the preliminary strike (mm)" after the third preliminary strike is "10 mm". Thus, the hammer drop height for the fourth preliminary strike is "103 mm" (= 10 mm ÷ 0.097).

[0149] The penetration amount of the fourth preliminary strike is "10 mm", and the "penetration amount per drop height" is 0.097 (= 10 mm ÷ 103 mm). Therefore, the "average value of the penetration amount per drop height" from the first to the fourth preliminary strikes is 0.097 (= (0.1 + 0.105 + 0.087 + 0.097) ÷ 4). Also, the "remaining distance of the preliminary strike (mm)" after the fourth preliminary strike is "0 mm". Thus, the preliminary strike ends with the fourth strike, and the next hammer drop height (mm) is not calculated.

[0150] Thus, the "penetration amount per blow (mm)" is proportional to the potential energy E (= mgh) of the hammer 201 to be dropped, and the potential energy E is proportional to the hammer drop height h (mm). That is, the "penetration amount per blow (mm)" is proportional to the hammer drop height h (mm). Therefore, by calculating the "penetration amount per drop height", the "next hammer drop height (mm)" (= "remaining pre-drilling distance" ÷ "penetration amount per drop height") required to penetrate the "remaining pre-drilling distance (mm)" by one blow can be estimated. When the "next hammer drop height (mm)" exceeds the upper limit value (760 mm), it is set to the upper limit value (760 mm), so that the cumulative penetration amount during pre-drilling does not exceed the specified penetration amount (150 mm) with the minimum required number of blows.

[0151] In addition, as a light hammering operation process during pre-drilling other than the above, a plurality of stepped heights lower than the specified height (760 mm) (for example, 1 step = 50 mm, 2 steps = 100 mm, 3 steps = 200 mm) are set, and the next hammer drop height is increased or decreased step by step according to the penetration amount of the previous blow. When the remaining pre-drilling distance (mm) becomes less than or equal to the penetration amount of the previous blow (mm), it is also possible to reduce the next hammer drop height step by step so that the cumulative penetration amount during pre-drilling does not exceed the specified penetration amount (150 mm). This stepped light hammering process will be described later with reference to FIG. 32.

[0152] Returning to FIG. 13, in step S26, the hammering operation flow is executed. The hammering operation flow will be described with reference to FIG. 15.

[0153] FIG. 15 is an explanatory diagram showing the hammering operation flow by the hammering device 200. First, in step SS1, the catcher 202 is lowered. The catcher 202 is lowered by the catcher slide cylinder 204. The lowering distance of the catcher 202 is measured by the first wire encoder 214.

[0154] In step SS2, the lower limit position of the catcher is detected. The "lower limit position of the catcher" is a position where the catcher 202 can grasp the hammer 201 without colliding with the hammer 201, and is detected by the second proximity sensor 219 (Fig. 9).

[0155] In step SS3, the catcher 202 is raised. The catcher 202 is in a state of grasping the hammer 201. Also, the rising distance or falling distance of the catcher 202 is measured by the first wire encoder 214 (Fig. 6).

[0156] In step SS4, it is detected that the hammer 201 has reached the hammer drop height. As described above with reference to Fig. 17, the hammer drop height in the preliminary strike is gradually increased or decreased according to the penetration amount of one strike and the remaining distance of the preliminary strike. Note that the hammer drop height in the "main strike" and "after strike" described later is 760 mm. Also, in order to stably raise the hammer 201 to the specified hammer drop height by the catcher 202 and then grasp the naturally falling hammer 201 without load at the lower limit position of the catcher, the main striking device 200 raises and lowers the hammer 201 to the specified hammer drop height by PID control. The PID control of this hammer drop height will be described later with reference to Figs. 28 to 31.

[0157] In step SS5, the catcher claw 202f is opened. In this case, the hydraulic oil (oil) flows into the oil chamber (Fig. 5) through the hydraulic port 202P, and the movable sleeve 202c (Fig. 5) is displaced downward. As a result, the cam 202e (Fig. 5) pushes open the catcher claw 202f, and the catcher claw 202f no longer engages with the head step portion 201a (Fig. 5). Thereby, the hammer 201 falls naturally along the guide rod 203.

[0158] In step SS6, the free fall of the hammer 201 is detected. When the signal of the second proximity sensor 219 (Fig. 9) changes from ON to OFF, the control unit 320 (Fig. 10) determines that the hammer 201 is in free fall and counts it as the number of strikes.

[0159] In step SS7, the penetration amount of one strike is measured. The penetration amount of one strike is the value obtained by subtracting the measured value of the second wire encoder 215 in step SS2 from the measured value of the second wire encoder 215 immediately after the strike.

[0160] In step SS8, it is determined whether the total penetration amount is 80 mm or more from the bottom of the test hole. If the total penetration amount is 80 mm or more from the bottom of the test hole (YES), step SS10 is executed. On the other hand, if the total cumulative penetration amount is less than 80 mm from the bottom of the test hole (NO), step SS1 is executed again. Note that this step SS9 is skipped in the "main strike" and "after strike" described later.

[0161] In step SS9, it is determined whether the bucket position is the "bucket avoidance lower end position". If the bucket position is the "bucket avoidance lower end position" (YES), step SS1 is executed again. On the other hand, if the bucket position is not the "bucket avoidance lower end position" (NO), step SS11 is executed.

[0162] In step SS10, the bucket 207 is lowered to the "bucket avoidance lower end position". The "bucket avoidance lower end position" corresponds to the position where the bucket slide cylinder 208 is most contracted and is detected by the fourth magnetic switch 221 (Fig. 10). The above steps SS1 to SS10 correspond to items 14 in Fig. 21 to item 16 in Fig. 22.

[0163] Returning to FIG. 13 again, in step S27, it is determined whether the cumulative penetration amount is 150 mm or more from the bottom of the test hole. If the cumulative penetration amount is 150 mm or more from the bottom of the test hole (YES), the process proceeds to step S28-1 and the "pre-driving" is terminated. On the other hand, if the cumulative penetration amount is less than 150 mm from the bottom of the test hole (NO), step S28-2 is executed.

[0164] In step S28-2, it is determined whether the number of blows at a hammer drop height of 760 is 50 or more. If the number of blows at a hammer drop height of 760 is 50 or more (YES), the process proceeds to [Test Interruption / Continuation Judgment]. This [Test Interruption / Continuation Judgment] will be described with reference to FIG. 16. On the other hand, if the number of blows at a hammer drop height of 760 is less than 50 (NO), steps S28-3, S28-4, and S28-5 are executed, and step S26 is executed again.

[0165] In step S29, it is determined whether the cumulative penetration amount is less than 450 mm from the bottom of the test hole. If the cumulative penetration amount is less than 450 mm from the bottom of the test hole (YES), the process proceeds to step S30 and the "main driving" is started. On the other hand, if the cumulative penetration amount is 450 mm or more from the bottom of the test hole (NO), the standard penetration test is terminated.

[0166] Note that instead of the light hammering process shown in FIG. 17, it is also possible to calculate the next hammer drop height by the light hammering process shown in FIG. 33.

[0167] As described above, when the cumulative penetration amount is 150 mm or more from the bottom of the test hole, the "pre-driving" is terminated. Even if the cumulative penetration amount is less than 150 mm from the bottom of the test hole, if the number of blows at a hammer drop height of 760 mm is 50 or more, the process proceeds to [Test Interruption / Continuation Judgment] (step 28-7) described later. Next, the "main driving" will be described.

[0168] As shown in FIG. 14, in step S30, the "main driving" is started.

[0169] In step S31, the hammer 201 is lifted to a hammer drop height of 760 mm.

[0170] In step S32, the striking operation flow is executed.

[0171] In step S33, it is determined whether the cumulative penetration amount is 450 mm or more from the bottom of the test hole. If the cumulative penetration amount is 450 mm or more from the bottom of the test hole (YES), the process proceeds to step S34 and "main driving" ends. On the other hand, if the cumulative penetration amount is less than 450 mm from the bottom of the test hole (NO), step S35 is executed.

[0172] In step S35, it is determined whether the cumulative number of strikes is 50 or more. If the cumulative number of strikes is 50 or more (YES), the process proceeds to [Test Interruption / Continuation Judgment] in step S28-7. This [Test Interruption / Continuation Judgment] will be described with reference to FIG. 16. On the other hand, if the cumulative number of strikes is less than 50 (NO), step S30 is executed again. Note that the above steps S30 to S35 correspond to items 17 to 19 in FIG. 22.

[0173] As described above, when the cumulative penetration amount is 450 mm or more from the bottom of the test hole, "main driving" ends. Even if the cumulative penetration amount is less than 450 mm from the bottom of the test hole, if the cumulative number of strikes at a hammer drop height of 760 mm is 50 or more, the process proceeds to [Test Interruption / Continuation Judgment] (step 28-7) described later. Subsequently, "after driving" will be described.

[0174] In step S36, it is determined whether to perform after driving or not. If not performing after driving (YES), the standard penetration test ends. On the other hand, if performing after driving (NO), the process proceeds to step S37 and "after driving" is started.

[0175] In step S37, "after driving" is started

[0176] In step S38, the hammer 201 is lifted to a hammer drop height of 760 mm.

[0177] In step S39, a striking operation is performed.

[0178] In step S40, it is determined whether the cumulative penetration amount is 500 mm or more from the bottom of the test hole. If the cumulative penetration amount is 500 mm or more from the bottom of the test hole (YES), the standard penetration test is terminated. On the other hand, if the cumulative penetration amount is less than 500 mm from the bottom of the test hole (NO), step S41 is executed.

[0179] In step S41, it is determined whether the cumulative number of strikes is 50 or more. If the cumulative number of strikes is 50 or more (YES), proceed to [Test Interruption / Continuation Judgment]. [Test Interruption / Continuation Judgment] will be described with reference to FIG. 16. On the other hand, if the cumulative number of strikes is less than 50 (NO), step S37 (rear strike start) is executed again. Note that the above steps S37 to the above step 41 correspond to items 20 to 22 of FIG. 24.

[0180] As described above, when the cumulative penetration amount is 500 mm or more from the bottom of the test hole, the "rear strike" ends. Even if the cumulative penetration amount is less than 500 mm from the bottom of the test hole, if the cumulative number of strikes at a hammer drop height of 760 mm is 50 or more, the process proceeds to [Test Interruption / Continuation Judgment] (step 28-7) described later. Subsequently, [Test Interruption / Continuation Judgment] will be described.

[0181] FIG. 16 is a flowchart showing the process of [Test Interruption / Continuation Judgment]. First, in step S28-6, it is determined whether the total penetration amount in the previous 50 strikes is less than 10 mm. If the cumulative penetration amount in the previous 50 strikes is less than 10 mm (YES), proceed to step S28-7 and interrupt the test. On the other hand, if the cumulative penetration amount in the previous 50 strikes is 10 mm or more, step S28-8 is executed.

[0182] In step S28-8, it is determined whether "pre-striking" is in operation. If "pre-striking" is in operation (YES), step S28-9 is executed. On the other hand, if "pre-striking" is not in operation (NO), the process proceeds to step S28-13 to determine whether it is the "main strike operation". If the "main strike" is in operation (YES), the process proceeds to step S28-14 to determine whether the number of main strike hits has reached 50. If the number of main strike hits has reached 50 (YES), the test is interrupted. On the other hand, if the number of hits is less than 50 (NO), the "main strike" operation continues.

[0183] In step S28-9, it is determined whether it is possible to switch from "pre-striking" to "main striking". If the number of strikes in the pre-striking interval reaches 50 (hammer drop height 760 mm), the N value is assumed to be 50 and it is possible to switch to the main strike. If it is possible to switch from "pre-striking" to "main striking" (YES), the main strike operation (step S30) is performed. On the other hand, if it is not possible to switch from "pre-striking" to "main striking" (NO), step S28-10 is executed.

[0184] In step S28-10, it is determined whether the cumulative number of strikes is equal to or exceeds the number of strike stops. The "number of strike stops" is the target value of the number of strikes to stop the striking operation automatically so as not to overstrike, and it is set by inputting the number of times. If the cumulative number of strikes is equal to or exceeds the number of strike stops (YES), the process proceeds to step S28-11 to interrupt the test. On the other hand, if the cumulative number of strikes is less than the number of strike stops (NO), the process proceeds to step S28-12 to perform either "pre-striking" or "post-striking".

[0185] By the way, after interrupting the test in step S28-7, the process proceeds to step S28-7-1 to determine whether to start the additional strike operation. If it is to start the additional strike operation (YES), the process proceeds to step S28-7-2 to execute the strike operation flow (Figure 15) until the number of additional strikes reaches the predetermined number. Then, the process returns to step S28-7. If it is not to start the additional strike operation (NO), the standard penetration test is terminated.

[0186] Similarly, after the test is interrupted in step S28-11, the process proceeds to step S28-11-1 to determine whether to start the additional striking operation. If it is determined to start the additional striking operation (YES), the process proceeds to step S28-11-2 and the striking operation flow (Figure 15) is executed until the number of additional strikes is reached. Thereafter, the process returns to step S28-11. If it is determined not to start the additional striking operation (NO), the process proceeds to step S28-11-4. If "pre-striking" is in operation (YES), the process returns to step S30 to perform the "main strike" operation. On the other hand, if "pre-striking" is not in operation (NO), the standard penetration test is terminated.

[0187] To terminate the standard penetration test, the operator presses the "test end button" on the SPT remote controller 330 (Figure 10). Thereby, the measurement data is saved.

[0188] Also, as shown in item 23 of Figure 25, the penetration measurement jig 223 is removed from the SPT sampler rod 1'. Thereafter, as shown in item 24 of Figure 25, the anvil 224 is detached from the SPT sampler rod 1', and the bucket 207 is raised by 100 mm.

[0189] Furthermore, as shown in item 25 of Figure 25, the bucket 207 is pivotally moved to the "standby position", and the wire WL is connected to the SPT sampler rod 1'. Thereafter, the first clamp mechanism 31 is opened, and the SPT sampler rod 1' is recovered by lifting it with the winch 35.

[0190] Figures 28 to 32 are explanatory diagrams showing PID control for hammer drop height installation by the SPT control unit 300. Figure 28 shows the valve position of the hydraulic control valve 204a for the catcher slide cylinder when the catcher 202 is rising. Figure 29 shows the valve position of the hydraulic control valve 202L for catcher release when the catcher claw 202f is open. Figure 30 shows the valve position of the hydraulic control valve 202L for catcher release when the catcher claw 202f is closed. Figure 31 shows the valve position of the hydraulic control valve 204a for the catcher slide cylinder when the catcher 202 is descending. Figure 32 shows the configuration related to feedback control for the hammer drop height using a PID controller, as well as the correlations between the catcher rising speed, valve opening degree, and hammer drop height, respectively.

[0191] As shown in Figure 28, when the catcher 202 is raised to install the hammer 201 at a specified hammer drop height, the hydraulic control valve 204a for the catcher slide cylinder switches the valve position to the extending side. As a result, the hydraulic oil (oil) pumped from the hydraulic pump flows into the piston-side cylinder 204c, causing the piston to displace upward. At the same time, the hydraulic oil in the rod-side cylinder 204b is pushed out by the piston and drained into the oil tank 204g through the hydraulic control valve 204a for the catcher slide cylinder. In this case, the hydraulic control valve 202L for catcher release switches the valve position to the stop side. Therefore, no hydraulic oil flows from the hydraulic pump into the oil chamber (Figure 5) of the catcher 202. The movable sleeve 202c is displaced upward by being pushed by the return spring 202d (Figure 5). As a result, the catcher claw 202f is pushed by the closing biasing spring 202g (Figure 5) and is in a closed state. The catcher 202 is in a state of gripping the hammer 201.

[0192] As shown in FIG. 29, when the catcher claw 202f is opened and the hammer 201 is allowed to fall freely, the hydraulic control valve 202L for catcher release switches the valve position to the extension side. As a result, the hydraulic oil (oil) pumped from the hydraulic pump flows into the oil chamber (FIG. 5), the movable sleeve 202c is displaced downward, and the cam 202e (FIG. 5) attached to the movable sleeve 202c engages with the catcher claw 202f, causing the catcher claw 202f to open outward. Thereby, the hammer 201 falls naturally. In this case, the hydraulic control valve 204a for the catcher slide cylinder switches the valve position to the stop side. As a result, the movement of the catcher slide cylinder 204 stops.

[0193] As shown in FIG. 30, when the catcher claw 202f is closed, the hydraulic control valve 202L for catcher release switches the valve position to the retraction side. As a result, the hydraulic oil (oil) flows out of the oil chamber (FIG. 5) by the return spring 202d, the movable sleeve 202c is displaced upward, and the cam 202e (FIG. 5) attached to the movable sleeve 202c no longer engages with the catcher claw 202f. Thereby, the catcher claw 202f is pushed by the closing bias spring 202g (FIG. 5) and closes. In this case, the hydraulic control valve 204a for the catcher slide cylinder switches the valve position to the stop side. As a result, the movement of the catcher slide cylinder 204 stops.

[0194] As shown in FIG. 31, when the catcher 202 is lowered to the hammer gripping position (the position where the second proximity sensor 219 detects the hammer 201), the hydraulic control valve 204a for the catcher slide cylinder switches the valve position to the retracted side. As a result, the hydraulic oil (oil) pumped from the hydraulic pump flows into the rod-side cylinder 204b and the piston is displaced downward. On the other hand, the hydraulic oil in the piston-side cylinder 204c is pushed out by the piston and drained to the oil tank 204g through the hydraulic control valve 204a for the catcher slide cylinder. In this case, the hydraulic control valve 202L for catcher release switches the valve position to the stop side. As a result, the hydraulic oil in the oil chamber (FIG. 5) of the catcher 202 is sealed, the movable sleeve 202c is stationary, and the catcher claw 202f maintains the closed state.

[0195] As shown in FIG. 32(a), in the control system related to the hammer drop height, the current hammer height H is fed back with respect to the target value H of the hammer drop height * to obtain the deviation e (= H * - H), and the deviation e is input to the PID controller to calculate the operation value u for the hydraulic control valve 204a of the catcher slide cylinder. The valve position of the hydraulic control valve 204a for the catcher slide cylinder is switched to the extended / retracted side by the operation value u, and thereby the catcher 202 (catcher slide cylinder 204) rises / descends. Therefore, the output value of this control system is the valve opening of the hydraulic control valve 204a for the catcher slide cylinder, the current hammer height, and the catcher rising / descending speed. And among the output values, the current hammer height H is fed back.

[0196] As shown in Fig. 32(b), for example, when raising the hammer from the catcher lower limit position (hammer gripping position) to the specified hammer drop height (760 mm), the voltage applied to the hydraulic control valve 204a for the catcher slide cylinder is maximized when the current hammer height is 0 (mm), and while maintaining the maximum voltage, the valve opening degree is set to 100% so that the rising speed of the catcher is the fastest, and when the current hammer height is 760 (mm), the valve opening degree becomes 0% and the control unit 320 (Fig. 10) controls the applied voltage so that the rising speed of the catcher 202 becomes zero.

[0197] Fig. 33 is an explanatory diagram showing another example of the light hitting operation process in preliminary hitting. Fig. 33(a) shows the stepwise increase / decrease determination of the hammer drop height based on the "penetration amount (mm) of the immediately previous hit" and the "remaining distance of preliminary hitting (mm)". The vertical axis shows the cumulative penetration amount (mm) and the remaining distance of preliminary hitting (mm) together, and the horizontal axis represents the number of hits (times). Therefore, the black circles indicate the cumulative penetration amount (mm) and the remaining distance of preliminary hitting (mm) immediately after hitting, and the vertical difference between adjacent black circles represents the penetration amount (mm) of one hit.

[0198] Fig. 33(b) shows the transition of the stages of the hammer drop height at each number of hits (times). In the light hitting operation process in preliminary hitting, the hammer drop height is stepwise increased or decreased according to the determination criteria within the range where the "penetration amount (mm) of the immediately previous hit" is smaller than the "remaining distance of preliminary hitting (mm)", while it is stepwise decreased within the range where the "penetration amount (mm) of the immediately previous hit" is equal to or larger than the "remaining distance of preliminary hitting (mm)". The following will be described in detail with reference to the drawings.

[0199] As shown in Fig. 33(b), the hammer drop height at the first preliminary hit is set to be at the lowest stage of "50 mm". As shown in Fig. 33(a), the penetration amount at the first preliminary hit is "5 mm", and this "5 mm" corresponds to "10 mm or less" in the [stepwise increase] determination. Therefore, the hammer drop height at the second preliminary hit becomes "100 mm" at the second stage with a one-stage increase.

[0200] Subsequently, the penetration amount of the second preliminary strike is "15 mm", and this "15 mm" corresponds to "more than 10 mm and less than 20 mm" in the [stage invariant] determination. Therefore, the hammer drop height of the third preliminary strike is the same two-stage "100 mm" as the second time.

[0201] The penetration amount of the third preliminary strike is "8 mm", and this "8 mm" corresponds to "10 mm or less" in the [stage increase] determination. Therefore, the hammer drop height of the fourth preliminary strike is the three-stage "200 mm" increased by one stage from the third time.

[0202] The penetration amount of the fourth preliminary strike is "8 mm", and this "8 mm" corresponds to "10 mm or less" in the [stage increase] determination. Therefore, the hammer drop height of the fifth preliminary strike is the four-stage "760 mm" increased by one stage from the fourth time.

[0203] The penetration amount of the fifth preliminary strike is "14 mm", and this "14 mm" corresponds to "more than 10 mm and less than 20 mm" in the [stage invariant] determination. Therefore, the hammer drop height of the sixth preliminary strike is the same four-stage "760 mm" as the fifth time.

[0204] The penetration amount of the sixth preliminary strike is "22 mm", and this "22 mm" corresponds to "20 mm or more" in the [stage decrease] determination. Therefore, the hammer drop height of the seventh preliminary strike is the three-stage "200 mm" decreased by one stage from the sixth time.

[0205] The penetration amount of the seventh preliminary strike is "14 mm", and this "14 mm" corresponds to "more than 10 mm and less than 20 mm" in the [stage invariant] determination. Therefore, the hammer drop height of the eighth preliminary strike is the same three-stage "200 mm" as the seventh time.

[0206] The penetration amount of the eighth preliminary strike is "17 mm", and this "17 mm" corresponds to "more than 10 mm and less than 20 mm" in the [stage invariant] determination. Therefore, the hammer drop height of the ninth preliminary strike is the same three-stage "200 mm" as the eighth time.

[0207] The penetration amount at the 9th preliminary strike is "25 mm", and this "25 mm" corresponds to "20 mm or more" in the [step-down] determination. Therefore, the hammer drop height at the 10th preliminary strike is "100 mm" at the second level, which is reduced by one level from the 9th time.

[0208] The penetration amount at the 10th preliminary strike is "11 mm", and this "11 mm" corresponds to "more than 10 mm and less than 20 mm" in the [step-unchanged] determination. Therefore, the hammer drop height at the 11th preliminary strike is "100 mm" at the second level, which is the same as the 10th time.

[0209] However, the penetration amount at the 10th preliminary strike (11 mm) is equal to the remaining distance of the preliminary strike (11 mm). Therefore, when the hammer drop height is "100 mm" at the second level, there is a risk that the cumulative penetration amount exceeds the specified penetration amount (150 mm) in the preliminary strike. Therefore, the hammer drop height at the 11th preliminary strike is "50 mm" at the first level, which is reduced by one level from the 10th time.

[0210] The penetration amount at the 11th preliminary strike is "7 mm", and "7 mm" corresponds to "10 mm or less" in the [step-up] determination. Therefore, the hammer drop height at the 12th preliminary strike is "100 mm" at the second level, which is increased by one level from the 11th time.

[0211] However, the penetration amount at the 11th preliminary strike (7 mm) is larger than the remaining distance of the preliminary strike (4 mm). Therefore, when the hammer drop height is "100 mm" at the second level, there is a risk that the cumulative penetration amount exceeds the specified penetration amount (150 mm) in the preliminary strike. Therefore, the hammer drop height at the 12th preliminary strike is "50 mm" at the first level, which is the same as the 11th time.

[0212] Thus, regarding the hammer drop height during preliminary driving, instead of setting it to the specified height (760 mm) from the beginning, a plurality of stepped heights lower than the specified height (760 mm) are set (1 step = 50 mm, 2 steps = 100 mm, 3 steps = 200 mm). The next hammer drop height is gradually increased or decreased according to the penetration amount of the previous strike. When the remaining distance (mm) of the preliminary driving becomes less than or equal to the penetration amount (mm) of the previous strike, the next hammer drop height is decreased step by step so that the cumulative penetration amount during the preliminary driving does not exceed the specified penetration amount (150 mm).

[0213] Note that the number of steps (4 steps) to reach the specified height (760 mm), each stepped height (1 step = 50 mm, 2 steps = 100 mm, 3 steps = 200 mm, 4 steps = 760 mm), and the determination reference values related to step increase / decrease (20 mm or more, 10 mm or less) are examples and can be appropriately set and changed according to the situation.

[0214] As described above, according to the striking device 200 according to the present invention, the entire device is compactly unitized as a single device and can be detachably attached to all bowling machines from small to large, whether self-propelled or stationary. Moreover, it is possible to realize a smooth lifting and lowering operation with little shaking up to the specified height for the catcher holding the hammer.

[0215] Also, according to the bowling device 100 according to the present invention, it becomes possible to automatically and efficiently perform a standard penetration test for a test hole into which an SPT sampler is inserted without the risk of hole wall collapse in a short time.

Explanation of Reference Numerals

[0216] 1 Boring rod 2 Core barrel 3 Overshot 10 Crawler device 11 Driving wheel 12 Idler wheel 13 Endless track 14 Rollover wheel 20 Vehicle body 24 Leader tilting mechanism 25 Leader slide mechanism 30 Leader device (feeding device) 31 First clamping mechanism 32 Second clamping mechanism 33 Leader body 33a Vertical groove 34 Sheave 35 Winch (lifting device) 36 Hydraulic cylinder 37 Head slide mechanism 38 Mast slide mechanism 40 Swivel head (rotary drive device) 41 Head end 42 Rotary motor 43 Head rotation part 44 Spindle 50 Water supply pump (water supply device) 100 Boring device (boring machine system) 200 Impact device (automatic standard penetration test device) 201 Hammer 202 Catcher (grasping and dropping mechanism) 202a Cylindrical part 202b Fixed sleeve 202c Movable sleeve 202d Return spring 202e Cam 202f Catcher claw 202g Closing bias spring 202h Casing 202i Slide piece 202j Connecting piece 202k O-ring 202L Catcher release hydraulic control valve 203 Guide rod 204 Catcher slide cylinder (first cylinder mechanism) 204a Hydraulic control valve for catcher slide cylinder 204b Rod side cylinder 204c Piston side cylinder 205 Catcher support mechanism 206 Catcher slide rail (first right-angled piece) 207 Bucket (hollow prism structure) 208 Bucket slide cylinder (second cylinder mechanism) 208a Hydraulic control valve for bucket slide cylinder 209 Bucket slide cylinder support mechanism (tunnel plate structure) 210 Bucket engaging piece (second right-angled piece) 211 First turning mechanism (turning mechanism) 211a Fixed part 211b Turning part 211c Turning shaft 212 Second turning mechanism (turning mechanism) 212a Fixed part 212b Turning part 212c Turning shaft 213 Rod locking part 214 First wire encoder 215 Second wire encoder 216 First magnetic switch 217 Second magnetic switch 218 First proximity sensor (target detection sensor) 219 Second proximity sensor (hammer detection sensor) 220 Third magnetic switch 221 Fourth magnetic switch 222 Swing cylinder 222a Hydraulic control valve for swing cylinder 223 Penetration measurement jig (projecting piece) 223a Left half ring piece part 223b Right half ring piece part 223c L-shaped piece part 223d U-shaped piece part 223e Female screw piece part 224 Anvil 225U Upper coupling 225L Lower coupling 226 Connecting member 227 Target 228 Sub-chuck 300 SPT Control Unit 310 Management Monitor Unit (Data Input Unit) 320 Control Unit 330 SPT Remote Control (Remote Operating Device) WL Wire TH Test Hole

Claims

1. A hammer (201) for applying an impact force to an SPT sampler rod (1'), a gripping and dropping mechanism (202) for gripping the hammer (201) and dropping it from a specified height (760 mm), a guide rod (203) for moving the hammer (201) and the gripping and dropping mechanism (202) coaxially, a first cylinder mechanism (204) for raising and lowering the gripping and dropping mechanism (202), and a control device (300) for controlling the first cylinder mechanism (204), An automatic standard penetration test device (200) capable of automatically performing a standard penetration test (SPT) defined by Japanese Industrial Standards (JIS), wherein the hammer (201), the gripping and dropping mechanism (202), and the guide rod (203) are stored inside a vertically long hollow prism structure (207) so as to be movable in the vertical direction with respect to the hollow prism structure (207), and the first cylinder mechanism (204) is integrated with the hollow prism structure (207), the hollow prism structure (207) is rotatable around a predetermined rotation axis (211c, 212c) by a rotation mechanism (211, 212), and is movable in the vertical direction with respect to the rotation mechanism (211, 212) An automatic standard penetration test device characterized by the above.

2. In the automatic standard penetration test device according to Claim 1, the hollow prism structure (207) is supported so as to be movable up and down by a second cylinder mechanism (208) fixed to the rotation mechanism (211, 212), and the second cylinder mechanism (208) is supported inside a tunnel plate structure (209) with both ends open and fixed to the rotation mechanism (211, 212) An automatic standard penetration test device characterized by the above.

3. In the automatic standard penetration test device according to Claim 1, the rotation mechanism (211, 212) includes a third cylinder mechanism (222) for rotating the hollow prism structure (207) around the rotation axis (211c, 212c) An automatic standard penetration test device characterized by the above.

4. In the automatic standard penetration test device according to Claim 1, on the inner surface of the hollow prism structure (207), two pairs of vertically long first right-angle pieces (206, 206) with which the gripping and dropping mechanism (202) slidably engages are provided in a facing manner, and on the head of the gripping and dropping mechanism (202), two slide pieces (202i) that slidably engage with the pair of first right-angle pieces (206, 206) are provided in a facing manner. An automatic standard penetration test device characterized by the above.

5. In the automatic standard penetration test device according to claim 2, On the outer surface of the hollow prism structure (207), a pair of vertically long second right-angled pieces (210, 210) that slide and engage on both sides of the tunnel plate structure (209) are provided. An automatic standard penetration test device characterized by the above.

6. In the automatic standard penetration test device according to claim 1, The hollow prism structure (207) includes a first wire encoder (214) with the tip of a wire connected to the rod tip of the first cylinder mechanism (204). An automatic standard penetration test device characterized by the above.

7. In the automatic standard penetration test device according to claim 6, The rod tip is connected to the gripping and dropping mechanism (202) by a plate-shaped support mechanism (205). An automatic standard penetration test device characterized by the above.

8. In the automatic standard penetration test device according to claim 2, A protruding piece (223) that protrudes laterally is fixed to the STP sampler rod (1'), and the tunnel plate structure (209) supports a second wire encoder (215) "with the tip of a wire connected to the protruding piece (223)". An automatic standard penetration test device characterized by the above.

9. In the automatic standard penetration test device according to claim 1, The gripping and dropping mechanism (202) has a hammer detection sensor (219) for detecting the hammer (201). An automatic standard penetration test device characterized by the above.

10. In the automatic standard penetration test device according to claim 1, The hollow prism structure (207) is provided with a target (227) indicating a reference height position of the hollow prism structure (207) so as not to interfere with the top (213) of the guide rod (203), and The tunnel plate structure (209) supports a target detection sensor (218) "for detecting the target (227)". An automatic standard penetration test device characterized by the above.

11. In the automatic standard penetration test device according to claim 1, The control device (300) calculates the average value of the "penetration amount per drop height" for the hammer drop height, estimates the "next hammer drop height (mm)" required to penetrate the "remaining pre-drilling distance (mm)" by one strike based on the average value of the "penetration amount per drop height", and when the estimated "next hammer drop height (mm)" exceeds a predetermined upper limit value (760 mm), sets it to the upper limit value (760 mm), so that the cumulative penetration amount during pre-drilling does not exceed the specified penetration amount (150 mm). An automatic standard penetration test device characterized by the above.

12. In the automatic standard penetration test device according to Claim 1, the control device (300) sets a plurality of stepped heights (50 mm, 100 mm, 200 mm) lower than a specified height (760 mm) for the hammer drop height, increases or decreases the next hammer drop height stepwise according to the penetration amount of the SPT sampler rod (1') per the previous strike, when the remaining pre-drilling distance (mm) becomes less than or equal to the penetration amount (mm) per the previous strike, decreases the next hammer drop height step by step so that the cumulative penetration amount during pre-drilling does not exceed the specified penetration amount (150 mm). An automatic standard penetration test device characterized by the above.

13. The automatic standard penetration test device (200) according to Claim 1, a drilling rod (1) with an open tip for drilling the ground, a core barrel (2) composed of an upper part (2a) locked to the inner peripheral surface of the drilling rod (1) and a "hollow cylindrical lower part (2b) that is rotatable relative to the upper part (2a) and has an open end", an overshot (3) for recovering the core barrel (2), a feeding device (30) for feeding the drilling rod (1) in a predetermined direction, a rotary drive device (40) for rotating the drilling rod (1), a water supply device (50) for supplying drilling water to the drilling rod (1), a lifting device (34, 35) for lifting the core barrel (2) to the ground, a first clamping mechanism (31) capable of gripping the SPT sampler rod (1'), a boring machine system (100) comprising a second clamping mechanism (32) capable of gripping the drilling rod (1), wherein the automatic standard penetration test device (200) is rotatably attached to the feeding device (30) or a fixing member. The test hole into which the SPT sampler rod (1') is inserted is configured to be drilled by a core barrel assembly in which the core barrel (2) is attached to the inner peripheral surface of the drilling rod (1). A boring machine system characterized by this.

14. In the boring machine system according to claim 13, The first clamping mechanism (31) is capable of attaching a sub-chuck (228) that can grip the SPT sampler rod (1'). A boring machine system characterized by this.

Images