Pile hole penetration test machine

Abstract

To provide a pile hole penetration tester capable of normally performing a measurement test even if the depth of the ground to be measured becomes deep. [Solution] An inner casing 3 held in an outer casing 2 so as to be able to rise and fall freely is provided with a penetration rod 6 together with a knocking block 37. The inner casing 3 is provided with a guide portion 35 and a weight 38 which is provided in the guide portion 35 so as to be able to rise and fall freely and which strikes the knocking block 37. The inner casing 3 is further provided with a geared motor 30, and a first pulley 31, a second pulley 32, a first drive belt 33, and a second drive belt 34 which, when driven by the geared motor 30, promote the raising and lowering of the weight 38.

Description

[Technical field]

[0001] The present invention relates to a pile hole penetration test machine. [Background technology]

[0002] A conventional pile hole penetration test machine is, for example, that described in Patent Document 1. The invention described in Patent Document 1 is configured as follows.

[0003] That is, in the conventional pile hole penetration test machine, a vertical cylindrical inner casing is held in a vertical cylindrical outer casing so as to be freely raised and lowered. A penetration rod hanging from the lower end of the inner casing penetrates the lower end of the outer casing and protrudes downward to the outside, a knocking block integrated with the penetration rod is fixed to the lower end of the inner casing, and a drive hammer is provided inside the inner casing to strike the knocking block by free fall. Furthermore, a lifting mechanism is provided to lift the drive hammer after the fall and lower it at a predetermined height, and the support strength is measured from the number of strikes of the drive hammer required for the penetration rod to penetrate from the bottom of the hole to a predetermined depth. The lifting mechanism is composed of a hydraulic cylinder arranged at the upper part of the inner casing, a slide guide frame provided at the tip of a piston rod protruding downward from the hydraulic cylinder, a pair of clamping pieces held by the slide guide frame so as to be freely slidable in the radial direction, a spring member that urges both clamping pieces in a mutual approach direction, and a clamp release member provided on the upper side of the inner casing. The lifting mechanism configured in this manner clamps the knob protruding from the drive hammer between both clamping pieces, lifts the drive hammer by shortening the piston rod, and when the clamping pieces are pressed against the clamp release member at their upper limit position, they move apart against the force of the spring member, releasing the drive hammer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6242466 Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, although the above-mentioned pile hole penetration test machine can provide a pile hole penetration test machine having excellent operational stability and durability of the lifting mechanism, there are the following problems.

[0006] The pile hole penetration test machine described above uses a hydraulic cylinder to operate the lifting mechanism, so when the ground to be measured becomes deeper (e.g., 50 m), the hydraulic hose that supplies hydraulic pressure to the hydraulic cylinder begins to sag. If the hydraulic hose sags, the pressure is reduced when hydraulic pressure is supplied to the hydraulic hose, and the lifting mechanism may not operate normally. This may result in a problem that the measurement test may not be performed normally.

[0007] In view of the above problems, the present invention aims to provide a pile hole penetration test machine that can perform measurement tests normally even when the depth of the ground to be measured becomes deep. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following means. Note that the parentheses indicate reference symbols of the embodiments described below, but the present invention is not limited thereto.

[0009] According to the invention of claim 1, in a pile hole penetration test machine (1) in which an inner casing (3) is held in an outer casing (2) so as to be capable of moving up and down, and a penetration rod (6) is provided together with a knocking block (37), Located at the center of the inner casing (3) A guide portion (35); The inner casing (3) is provided therein, The guide portion (35) is provided with a movable member. and is provided at the lower part of the guide portion (35). A weight (38) that strikes the knocking block (37); a stopper (36) provided in the inner casing (3) and on an upper portion of the guide portion (35); The inner casing (3) is provided with A motor (geared motor 30), a first pulley (31) provided in the inner casing (3) and connected to the motor (geared motor 30) via a first drive belt (33); a second pulley (32) provided in the inner casing (3) and connected to the first pulley (31) via a second drive belt (34), the first pulley (31) and the second pulley (32) are disposed in the inner casing (3) at positions parallel to a direction in which the weight (38) moves up and down; The weight (38) is provided between the stopper (36) and the knocking block (37), and has a recess (locking portion 38a) on its side. The second drive belt (34) is provided with a protrusion (a latched portion 34a) that protrudes outward and is integrally formed therewith, When the motor (geared motor 30) is driven, the first pulley (31) rotates via the first drive belt (33), and the second pulley (32) rotates via the second drive belt (34). As a result, the protrusion (engaged portion 34a) on the second drive belt (34) is inserted into a recess (engaging portion 38a) on the weight (38) and engaged therewith, thereby lifting the weight (38) along the guide portion (35). At this time, as the weight (38) rises, it comes into contact with the stopper (36) and its rise is restricted. However, since the second drive belt (34) continues to move, the protrusion (engaged portion 34a) engaged in the recess (engaging portion 38a) comes out of the recess (engaging portion 38a), thereby releasing the engagement. Thereafter, the weight (38) descends along the guide portion (35) and strikes the knocking block (37). It is characterized by the following. Effect of the Invention

[0012] Next, the effects of the present invention will be described with reference to the drawings. Note that the reference symbols in the parentheses are those of the embodiments described below, but the present invention is not limited thereto.

[0013] According to the invention of claim 1, When the motor (geared motor 30) is driven, the first pulley (31) rotates via the first drive belt (33), and the second pulley (32) rotates via the second drive belt (34). As a result, the protrusion (engaged portion 34a) of the second drive belt (34) is inserted into and engaged with the recess (engaging portion 38a) of the weight (38), allowing the weight (38) to rise along the guide portion (35). At this time, as the weight (38) rises, the weight (38) comes into contact with the stopper (36) and is restricted from rising, but the second drive belt (34) continues to move, so that the protrusion (engaged portion 34a) engaged with the recess (engaging portion 38a) comes out of the recess (engaging portion 38a). This releases the lock, after which the weight (38) descends along the guide portion (35) and strikes the knocking block (37). Therefore, there is no need to use a hydraulic cylinder as in the conventional method for raising and lowering the weight (38), and the problems as in the conventional method do not occur.

[0014] Therefore, according to the present invention, even if the depth of the ground (G) to be measured increases, the measurement test can be performed normally.

[0015] Also, Claim 1 According to the invention ,mechanism This simplifies the process, thereby significantly improving the time required for measurement and testing.

[0016] moreover, Claim 1 According to the present invention, the weight (38) can be easily Raise and lower It is possible. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a vertical sectional front view of a pile hole penetration test machine according to an embodiment of the present invention. [Diagram 2]10A and 10B are explanatory diagrams for explaining a method of lowering the weight according to the embodiment, in which (a) shows a state in which the weight is raised to the position of the stopper, and (b) shows a state in which the weight is lowered from the position of (a) to the position of the knocking block. [Diagram 3] 11A and 11B are explanatory diagrams for explaining a method of raising the weight in accordance with the embodiment, in which (a) shows a state in which the weight is about to rise from the position of the knocking block, and (b) shows a state in which the weight is about to rise to the position of the stopper. [Figure 4] 1A shows the operation of the pile hole penetration test machine according to the embodiment during a penetration test, in which (a) shows the state where the penetration rod abuts against the bottom of the hole, (b) shows the state at the start of the test, and (c) is a front view showing the state where the penetration rod has penetrated the ground at the bottom of the hole. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] <Explanation of pile hole penetration test machine> Hereinafter, an embodiment of a pile hole penetration test machine according to the present invention will be described in detail with reference to the drawings. In the following description, when directions such as up, down, left and right are indicated, they refer to up, down, left and right when viewed from the front of the figure.

[0019] As shown in Fig. 1, the pile hole penetration test machine 1 according to this embodiment includes a vertical cylindrical outer casing 2. As shown in Fig. 1, the outer casing 2 is provided with an attachment part 20 having a vertically elongated semi-elliptical shape in a front view, which is integrally provided in the central position of the upper part 2a and faces upward in the figure. Furthermore, as shown in Fig. 1, the upper part 2a of the outer casing 2 is provided with a power cord adapter 21 on the left side of the attachment part 20 in the figure.

[0020] 1, legs 22 each having a vertically elongated rectangular shape when viewed from the front are integrally provided on each of the left side surface 2c and right side surface 2d of the lower portion 2b of the outer casing 2. Furthermore, as shown in FIG. 1, stabilizers 23 each having a horizontally elongated semicircular shape when viewed from the front are integrally provided on each of the left side surface 2c and right side surface 2d of the outer casing 2 so as to protrude outward.

[0021] Thus, as shown in Fig. 1, a vertically tubular inner casing 3 is concentrically loaded within the outer casing 2 configured as described above so as to be movable up and down. As shown in Figs. 1 to 3, a geared motor 30 is attached and fixed to the inner wall surface on the left side surface 3d of the upper portion 3a of the inner casing 3. A power cord 4 for supplying power to the geared motor 30 is connected to the geared motor 30 via a power cord adapter 21, as shown in Figs. 1 to 3.

[0022] Furthermore, inside the inner casing 3, as shown in Figures 1 to 3, a first pulley 31 is attached and fixed to the inner wall surface on the right side 3c side of the upper part 3a of the inner casing. And, inside the inner casing 3, as shown in Figures 1 to 3, a second pulley 32 is attached and fixed to the inner wall surface on the right side 3c side of the lower part 3b of the inner casing. Note that, as shown in Figures 1 to 3, the first pulley 31 and the second pulley 32 are provided at a distance from each other so as to be parallel to each other in the vertical direction in the figures.

[0023] 1 to 3, a first drive belt 33 formed of a chain or the like is wound between the geared motor 30 and the first pulley 31. Furthermore, as shown in Figs. 1 to 3, a second drive belt 34 formed of a chain or the like is wound between the first pulley 31 and the second pulley 32. As a result, when the geared motor 30 is driven to rotate, the first pulley 31 rotates via the first drive belt 33, and when the first pulley 31 rotates, the second pulley 32 rotates via the second drive belt 34.

[0024] 1 to 3, a guide portion 35 having a long and thin rod shape in a front view and extending in the vertical direction from the inner wall surface of the upper portion 3a toward the inner wall surface of the lower portion 3b is provided at a central position inside the inner casing 3. Note that, as shown in FIGS. 1 to 3, this guide portion 35 is provided so as to be parallel to the arrangement position between the first pulley 31 and the second pulley 32.

[0025] 1 to 3, an upper portion 35a of the guide portion 35 is attached and fixed to a stopper 36 having an inverted trapezoidal shape when viewed from the front. The stopper 36 is attached and fixed to the inner wall surface of the inner casing 3 on the upper portion 3a side, as shown in FIG.

[0026] 1 to 3, a lower portion 35b of the guide portion 35 is attached and fixed to a knocking block 37 having a rectangular shape when viewed from the front. The knocking block 37 is attached and fixed to the lower portion 3b side of the inner casing 3, as shown in FIG.

[0027] Thus, the weight 38 is provided so as to be able to rise and fall in the guide portion 35 configured as above, as shown in Figures 1 to 3. To explain in more detail, the weight 38 is provided so as to be able to rise and fall in the guide portion 35 located between the stopper 36 and the knocking block 37, as shown in Figures 1 to 3. As a result, the weight 38 rises to the position of the stopper 36, as shown in Figure 2(a), and descends to the position of the knocking block 37, as shown in Figure 2(b).

[0028] The weight 38 is formed with a mass of 63.5±0.5 kg in accordance with the standard penetration test stipulated in JIS A 1219, and as shown in Figs. 1 to 3, a recessed locking portion 38a is provided on the upper side of the left and right sides when viewed from the front. As shown in Fig. 3, a rectangular locked portion 34a that is integrally provided on the second drive belt 34 and protrudes outward can be locked to the locking portion 38a. Thus, when the locked portion 34a is locked to the locking portion 38a as shown in Fig. 3, the weight 38 rises along the guide portion 35 due to the rotation of the second drive belt 34. On the other hand, when the locked portion 34a is released from the locking portion 38a as shown in Fig. 2, the weight 38 descends along the guide portion 35 due to its own weight as shown in Fig. 2(b).

[0029] Thus, the various members as described above are provided inside the inner casing 3.

[0030] 1 to 3, an encoder 5 is attached and fixed to the inner wall surface of the upper part 2a of the outer casing 2. Then, as shown in FIGS. 1 to 3, a measurement cord 5a extending from this encoder 5 is attached and fixed to the center position of the upper part 3a of the inner casing 3. This enables the encoder 5 to measure the amount of descent of the inner casing 3 relative to the outer casing 2.

[0031] On the other hand, as shown in Figs. 1 to 3, a penetration rod 6 is provided in the lower part 3b of the inner casing 3. To explain in more detail, as shown in Fig. 1, the penetration rod 6 is formed in an elongated rod shape extending in the vertical direction as viewed from the front. As shown in Fig. 1, the upper part 6a of the penetration rod 6 is inserted into the knocking block 37. Thus, in this state, when the fixing ring 7 shown in Figs. 1 and 3 is screwed and fixed to the penetration rod 6 and the knocking block 37, the penetration rod 6 is provided in the lower part 3b of the inner casing 3.

[0032] On the other hand, as shown in Fig. 1, the lower part 6b of the penetration rod 6 is provided to penetrate the accumulator 8 provided in the outer casing 2 and protrude outward. Note that a sampler 6b1 that can be split into two for collecting geological samples is provided at the tip side of the lower part 6b of the penetration rod 6 shown in Fig. 1.

[0033] The inside of the accumulator 8 is under high pressure due to the inclusion of compressed air. The accumulator 8 prevents muddy water and earth and sand from entering the outer casing 2 through the penetration part of the penetration rod 6 during drilling due to its internal pressure, and is detachably bolted to the lower part 2b of the outer casing 2 as an independent member. As shown in FIG. 1, the penetration rod 6 is airtightly inserted through the openings of the upper part 8a and the lower part 8b of the accumulator 8 via bearing members 8c and 8d with inner peripheral O-rings. As shown by the imaginary line in FIG. 1, the lower end of the inner casing 3, i.e., the knocking block 37, is adapted to abut against the upper bearing member 8c. As a result, the lower limit position of the inner casing 3 in the outer casing 2 is this position.

[0034] The above is a description of the pile hole penetration test machine 1 according to this embodiment.

[0035] <Explanation of examples of use of pile hole penetration tester> Next, a usage example of the pile hole penetration test machine 1 according to the present embodiment described above will be described.

[0036] When measuring the bearing strength of the ground at the bottom of the hole by the pile hole penetration test machine 1, first, the mounting part 20 of the outer casing 2 is fitted and pinned into the lower end opening (not shown) of the kelly bar K held by the earth drill machine (not shown) as shown in FIG. 4(a). In this way, the pile hole penetration test machine 1 is connected to the lower end of the kelly bar K. In this connected state, the pile hole penetration test machine 1 is supported by the kelly bar K on the outer casing 2 side, so that the inner casing 3 is placed at the lowest position in the outer casing 2 by its own weight as shown in FIG. 4(a). As a result, the protruding length of the penetration rod 6 from the lower part 2b (see FIG. 1) of the outer casing 2 becomes maximum as shown in FIG. 4(a).

[0037] Thus, the pile hole penetration test machine 1 connected to the lower end of the Kelly bar K lowers the Kelly bar K without rotating, and inserts it into the pile hole H previously formed, as shown in FIG. 4(a), and lowers it so as not to contact the hole wall, so that the tip of the penetration rod 6 abuts against the hole bottom Ha. However, as shown in FIG. 4(a), when the tip of the penetration rod 6 abuts against the hole bottom Ha, the descent of the inner casing 3 stops. However, since the outer casing 2 can be raised and lowered relatively to the inner casing 3, the penetration rod 6 retreats into the outer casing 2 as shown in FIG. 4(b), and the outer casing 2 descends together with the Kelly bar K. Then, as shown in FIG. 4(b), when the leg 22 provided on the outer casing 2 abuts against the hole bottom Ha, the descent of the outer casing 2 and the Kelly bar K stops, and the protruding length of the penetration rod 6 from the lower part 2b (see FIG. 1) of the outer casing 2 becomes minimum. In this state, the kelly bar K is fixed so that it cannot be raised or lowered, and a measurement test is carried out using the pile hole penetration tester 1 as follows.

[0038] In the measurement test, first, the geared motor 30 shown in FIG. 2(a) is rotated. As a result, the first pulley 31 rotates via the first drive belt 33, and when the first pulley 31 rotates, the second pulley 32 rotates via the second drive belt 34. Accordingly, with this rotation, the second drive belt 34 moves in the direction of the arrow Y1 as shown in FIG. 2(a). As a result, the locked portion 34a, which was locked by the locking portion 38a as shown in FIG. 2(a), is released from the lock as shown in FIG. 2(b). Accordingly, the weight 38 descends by its own weight along the guide portion 35 as shown in FIG. 2(b) (see arrow Y2). Thus, due to this descent, the weight 38 strikes the knocking block 37 as shown in FIG. 2(b). This striking force causes the inner casing 3 to descend, and the penetration rod 6 penetrates into the ground G at the bottom of the hole Ha, as shown in FIG. 4(c).

[0039] On the other hand, when the second drive belt 34 moves further, the locked portion 34a is locked again by the locking portion 38a as shown in FIG. 3(a). Thus, when the second drive belt 34 moves in the direction of the arrow Y3 (upward in the figure) as shown in FIG. 3(a), the locked portion 34a moves in the direction of the arrow Y3 (upward in the figure) while remaining locked by the locking portion 38a. As a result, the weight 38 rises along the guide portion 35 as shown in FIG. 3(b), and rises to the position of the stopper 36 as shown in FIG. 2(a). Then, again, as described above, the locked portion 34a that was locked by the locking portion 38a is released from the lock as shown in FIG. 2(b), and the weight 38 strikes the knocking block 37.

[0040] In this manner, the above process is repeated in the same manner, and the striking operation is repeated. In this manner, the number of strikes required for the penetration rod 6 to penetrate from the hole bottom Ha to a predetermined depth is measured, and based on the number of strikes, it is determined whether the bearing strength of the ground G at the hole bottom Ha is equal to or greater than a predetermined value.

[0041] The number of strikes (N value) of the weight 38 can be calculated by checking the number of revolutions of the geared motor 30, because the position of the locked portion 34a can be known by the number of revolutions of the geared motor 30. The amount of penetration of the penetration rod 6 into the ground G at the hole bottom Ha is measured by the encoder 5 as the amount of descent of the inner casing 3. The measurement signal from this encoder 5 is sent to an automatic measuring device (not shown) on the ground, and the amount of subsidence per strike, i.e., the amount of penetration of the penetration rod 6 into the ground G and the cumulative amount of penetration, are recorded and displayed together with the number of strikes (N value). In the standard penetration test stipulated in JISA1219, a weight 38 having a mass of 63.5±0.5 kg is allowed to fall freely 76±1 cm to strike the knocking block 37, and the number of strikes required for the penetration rod 6 having an outer diameter of 51±1 mm and an inner diameter of 35±1 mm to penetrate 30 cm into the ground is expressed as an N-value. Therefore, with this pile hole penetration test machine 1, the support strength can be grasped as an N-value in accordance with the above-mentioned standard penetration test.

[0042] Thus, the measurement test is carried out in this manner.

[0043] The above description is an example of the use of the pile hole penetration test machine 1 according to this embodiment.

[0044] Therefore, by using the pile hole penetration test machine 1 described above, there is no need to use a hydraulic cylinder as in the conventional method to raise and lower the weight 38, and therefore no problems as in the conventional method occur. Therefore, according to this embodiment, even if the depth of the ground G to be measured becomes deep, the measurement test can be performed normally.

[0045] <Description of Modifications> The above detailed description is the pile hole penetration tester 1 and its use example in this embodiment. However, the shape and the like shown in this embodiment are merely an example, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. For example, in this embodiment, an example is shown in which the mechanism of the first pulley 31, the second pulley 32, the first drive belt 33, and the second drive belt 34 is used to promote the elevation and lowering of the weight 38, but the present invention is not limited to this, and any mechanism may be used as long as it can promote the elevation and lowering of the weight 38 with the rotational drive of the geared motor 30. However, it is preferable to use the mechanism shown in this embodiment. This mechanism is simpler than the conventional mechanism in which the drive hammer is clamped, lifted, released, and then clamped again, and therefore the working time of the measurement test is greatly improved.

[0046] In the present embodiment, an example has been shown in which the second drive belt 34 is provided with the locked portion 34a and the weight 38 is provided with the locking portion 38a, and the weight 38 is prompted to ascend and descend by whether or not the locked portion 34a is locked to the locking portion 38a, but the present invention is not limited to this, and any configuration may be used as long as it can facilitate the elevation and descending of the weight 38. However, the configuration shown in the present embodiment is preferable, because such a configuration can easily facilitate the elevation and descending of the weight 38.

[0047] In the present embodiment, an example has been shown in which one mechanism including the geared motor 30, the first pulley 31, the second pulley 32, the first drive belt 33, and the second drive belt 34 is provided, but a plurality of such mechanisms may be provided.

[0048] Further, in the present embodiment, an example has been shown in which the second drive belt 34 is provided with one locked portion 34a, but the present invention is not limited to this, and a plurality of locked portions 34a may be provided.

[0049] Further, in this embodiment, the geared motor 30 is exemplified, but the present invention is not limited to this and any type of motor may be used. [Explanation of symbols]

[0050] 1. Pile hole penetration test machine 2 Outer casing 3 Inner casing 6 Penetrating Rod 30 Geared motor (motor) 31 First pulley (operating mechanism) 32 Second pulley (operating mechanism) 33 First drive belt (operating mechanism) 34 Second drive belt (operating mechanism) 34a Locked part 35 Guide section 37 Knocking Block 38 Weight 38a Locking part G. Ground

Claims

[Claim 1] In a pile hole penetration test machine, an inner casing is held in an outer casing so as to be able to rise and fall, and a penetration rod is provided together with a knocking block. A guide portion provided at a central position within the inner casing; a weight provided in the inner casing, and provided on the guide portion so as to be capable of ascending and descending, for striking the knocking block provided on a lower portion of the guide portion; a stopper provided in the inner casing and on an upper portion of the guide portion; A motor provided within the inner casing; a first pulley provided in the inner casing and connected to the motor via a first drive belt; a second pulley provided within the inner casing and connected to the first pulley via a second drive belt; the first pulley and the second pulley are disposed in the inner casing at positions parallel to a direction in which the weight moves up and down; The weight is provided between the stopper and the knocking block, and has a recess on a side surface thereof. The second drive belt is provided with a protrusion that protrudes outward and is integrally provided thereon, When the motor is driven, the first pulley rotates via the first drive belt, and further, the second pulley rotates via the second drive belt, whereby the protrusion on the second drive belt is inserted into and engaged with a recessed hole in the weight, allowing the weight to be raised along the guide portion. At this time, as the weight rises, it comes into contact with the stopper and its rise is restricted, but as the second drive belt continues to move, the protrusion engaged in the recessed hole comes out of the recessed hole, thereby releasing the engagement, and the weight then descends along the guide portion and strikes the knocking block. This is a pile hole penetration test machine.

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