JP3371998B2 - Penetration testing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a penetration tester for investigating soil properties by a penetration test.

[0002]

2. Description of the Related Art Conventionally, a penetration tester has been used for a penetration test for investigating soil properties. This penetration tester has a loading platform that can move up and down along the frame, and this loading platform is equipped with a motor and a chuck unit that rotates by receiving the drive of this motor. Are rotatably held together. This penetrating rod generally has a structure in which a substantially conical penetrating body is attached to the tip of a shaft-shaped member having no irregularities on the outer peripheral surface.

[0003]

Since the penetrating rod is composed of a shaft-shaped member having no unevenness on the outer peripheral surface, the chuck unit used to hold the penetrating rod is
For example, only a chuck unit that holds an axial component such as a hammer chuck that is originally used in a lathe of a component cutting machine can be applied, and slip occurs between the chuck unit and the chuck unit during the penetration test, resulting in accurate rotation of the penetration rod. There are problems such as the inability to measure quantities. In addition, in the type of penetration tester that measures the rotational load torque that various soils exert on the penetration body during the penetration test, the accurate torque must be stably measured due to the slip between the chuck unit and the penetration rod. There are problems such as difficulty in

The present invention has been made in view of the above problems, and an object of the present invention is to provide a penetration tester which does not cause slippage between the penetration rod and the chuck unit.

[0005]

In order to achieve the above object, the present invention provides a loading platform that can be raised and lowered along a frame.
A chuck unit that is rotatably arranged on the loading table and has an inner hole that penetrates through the entire length and that has an engaging means that is provided so as to always project into the inner hole; and a chuck unit that is rotationally driven. In a penetration testing machine including a drive source section for driving the chuck unit and a penetration rod held by the chuck unit, the penetration rod is a main body shaft section formed of a shaft-shaped member that can be inserted through an inner hole of the chuck unit. A penetrating body is attached to one end of the main body shaft portion, and an extension rod can be connected to the other end, and the other end of the main body shaft portion projects from the inner hole of the chuck unit on the main body shaft portion. It is characterized in that it is provided with a long groove-shaped engaging portion which is engageable with the engaging means in the chuck unit and has a long length with respect to the engaging means. In addition, it is desirable that a plurality of the engaging portions are arranged by equally dividing the outer periphery of the main body shaft portion. Further, the engaging portion has an arc-shaped cross section, and the engaging means engages with the engaging portion. It is desirable that the steel balls fit together.

[0006]

According to the present invention, the main body shaft portion is held in the chuck unit by inserting the main body shaft portion into the inner hole of the chuck unit and engaging the engaging portion of the chuck unit with the engaging portion of the main body shaft portion. As a result, it is possible to prevent slippage between the penetrating rod and the chuck unit. Further, since the locking portion is formed in a long groove shape, workability when mounting the penetrating rod on the chuck unit is improved, and further, by forming the locking portion in an arc-shaped cross section, By using steel balls as the engaging means of the unit, it is possible to prevent stress concentration on the locking portion due to rotational load torque or the like.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 4, 10 is a penetration tester, which has a pair of frames 11 having an inverted T-shape on the side, and a loading platform 12 is fitted in the frames 11 so as to be movable up and down. This loading platform 1
2, a motor 13 which is a drive source, a chuck unit 15 which is connected to the motor 13 by a chain 14 and which is driven by the motor 13 to rotate, and a weight 16 of various weights for applying a heavy load to the loading table 12. Hanging 1 to suspend
7 and a sprocket 18 that meshes with a chain 14 that connects the motor 13 and the chuck unit 15 to each other.
The chuck unit 15 holds the penetrating rod 1.

The chuck unit 15 in this penetration testing machine has a mounting plate 21 mounted on the loading table 12 as shown in FIG. 5, and the lower surface of the mounting plate 21 is a bearing case protruding toward the lower surface of the loading table 12. A bearing 22 is fixed, a thrust bearing and a radial bearing are housed in the bearing case 22, and a hollow cylindrical lower end sleeve 23 is inserted through the bearings. A sprocket 24 around which the chain 14 is wound is arranged below the lower end sleeve 23, and a relay sleeve 25 having a through-hole similar to the lower sleeve 23 is integrally rotatably arranged at the upper end. The bottom sleeve 23
A guide sleeve 26 having a through-hole continuous therethrough is integrally rotatably attached.

A storage hole 26a is formed in the upper part of the guide sleeve 26 by dividing the outer circumference into three equal parts and the inner hole side is narrowed to a slightly smaller diameter. A steel ball 27 is formed in the storage hole 26a. It is stored on the side so that it can protrude a predetermined amount. A spring 28 is fitted on the outer peripheral surface of the guide sleeve 26, and a hollow cylindrical sliding sleeve 29, which is constantly urged upward by the spring 28, is inserted through the sliding sleeve 29. The upper part of the hole has a larger diameter than the others.

The penetrating rod 1 is inserted through the chuck unit 14. As shown in FIG. 1, the penetrating rod 1 is integrally formed with a shaft-like main body shaft portion 2, a substantially conical penetrating body 3 provided at one end of the main body shaft portion 2, and the other end of the main body shaft portion 2. On the outer periphery formed of the male screw portion 4 and on the other end side of the main body shaft portion 2 where the male screw portion 4 is not formed, a locking portion 5 having the same length is formed by dividing the outer periphery into three equal parts.

As shown in FIG. 2, the engaging portion 5 is a long groove having a circular cross section, and the chuck unit 15 described above is used.
Of the steel ball is formed to have a depth suitable for engaging with the protrusion. In the penetration test, the extension rod 6 shown in FIG. 3 is prepared because the length of the penetration rod 1 is insufficient. The extension rod 6 is formed at one end with a female screw portion 7 that is screwed into the male screw portion of the penetrating rod 1, and at the other end, is integrally formed with the male screw portion 4 and the locking portion 5 like the penetrating rod 1. The extension rod 6 is formed by forming a female screw portion 7 in place of the penetrating body 3 of the penetrating rod 1.

When conducting a penetration test using the penetration tester 10, first, the loading table 12 is raised to a predetermined position along the frame 11. In this state, the chuck unit 15
When the sliding sleeve 29 is pulled down, the upper inner hole reaches the position of the steel ball 27 of the guide sleeve 26, and the steel ball 27 can be operated in the storage hole 26a. Then, when the penetrating rod 1 is inserted into the chuck unit 15 while keeping the sliding sleeve 29 pulled down, the steel ball 27 is pushed into the accommodation hole 26a by the penetrating rod 1 and the guide sleeve 2
6 Project from the outer peripheral surface.

In this state, when the pulling down force of the sliding sleeve 29 is released, the sliding sleeve 29 tries to slide upward by the restoring force of the spring 28, but the steel ball 27 causes the locking portion 5 of the penetrating rod 1 to move. If not, the steel ball 27 abuts on the boundary between the upper inner hole and the inner hole continuous with the upper hole, that is, the stepped portion due to the difference in diameter, so that the sliding sleeve 29 slides further upward. It cannot move and stops at that position. When the penetrating rod 1 is operated so that the engaging portion 5 of the penetrating rod 1 moves to the storage hole 26a position of the guide sleeve 26 from this state, the steel ball 27 is pressed by the sliding sleeve 29, so that the engaging portion When it coincides with 5, the engaging portion 5 is quickly engaged, and accordingly, the sliding sleeve 29 slides upward, and the accommodation hole 26a is covered with the inner hole to close the operation of the steel ball 27. As a result, the penetrating rod 1 is held by the chuck unit 15.

After the holding of the penetrating rod 1 is completed, a weight 16 having a predetermined weight is hung on the weight hanging 17 and the loading platform 12 is lowered until the tip of the penetrating body 3 of the penetrating rod 1 comes into contact with the ground surface.
From this state, the loading platform 12 is lowered by its own weight combined with the weight of the weight 16, and the motor 13 is driven to rotate the chuck unit 15 to penetrate the ground while rotating the penetrating body 3. The rotational load torque received by the penetrating body 3 is detected by the torque detection unit 20, and the amount of rotation of the penetrating body 3 for each predetermined penetrating amount is also recorded sequentially, and these data are used as soil determination data.

At this time, since the engaging portion 5 is formed on the outer peripheral surface of the penetrating rod 1, the chuck unit 15 can be provided with the steel ball 27 fitted into the engaging portion 5, and the penetrating rod 1 can be provided. 1 can be reliably held by the chuck unit 15, and by this, the drive of the motor 13 can be reliably transmitted to the penetrating rod 1, and the rotational load torque received by the penetrating body 3 can be reliably taken out. Is possible. Further, since the locking portion 5 of the penetrating rod 1 has a circular cross-sectional shape, it has a large contact area with the steel ball 27 and prevents concentration of stress due to rotational load torque or the like.

Since the above-mentioned penetration test is generally performed up to a depth of about 15 m, the extension rod 6 is replenished several times during the test. Here, the operation of joining the extension rod 6 to the penetrating rod 1 will be described, but the same is true for the subsequent addition of the extension rods 6 to each other. When connecting the extension rod 6 to the penetrating rod 1, first, the driving of the motor 13 is stopped, and the female screw portion 7 of the extension rod 6 is screwed into the male screw portion 4 of the penetrating rod 1 penetrating into the ground. Next, while sliding the sliding sleeve 29 of the chuck unit 15 downward, the chuck unit 15 is moved until the steel ball 27 is disengaged from the locking portion 5.
When is rotated, the sliding sleeve 29 is blocked by the steel ball 27 and cannot return upward as described above. Subsequently, when the loading platform 12 is lifted from this state to move the chuck unit 15 to the vicinity of the locking portion 5 of the extension rod 6 and the chuck unit 15 is rotated again, the steel ball 27 moves to the extension rod 6
The extension rod 6 is held by being fitted to the locking portion 5 of.

[0017]

According to the penetration tester of the present invention, the penetration rod is provided with the engaging portion of the chuck unit, which is engaged with the engaging means of the chuck unit, and has a long groove-like engaging portion having a length longer than that of the engaging means. Therefore, it is possible to prevent the chuck unit and the penetrating rod from slipping and firmly hold the penetrating rod in the chuck unit. Therefore, in the penetration test, the rotation amount of the penetration rod can be reliably measured, and the rotational load torque that acts on the penetration body in the ground can be reliably transmitted to the chuck unit, enabling accurate torque measurement. There are advantages such as Further, there is also an advantage that the extension rod can be added without removing the penetrating rod from the chuck unit, and the workability required for adding the rod is improved.

Further, since the engaging portion is formed in a long groove shape, when the penetrating rod is held in the chuck unit, the steel ball position on the chuck unit side and the engaging portion on the penetrating rod side are not accurately aligned. In addition, it is possible to improve workability.

Further, since the cross-sectional shape of the engaging portion is arcuate, when a steel ball is used as the engaging means of the chuck unit, the contact area with the steel ball is increased, and rotational load torque or the like acts. When doing so, it is possible to prevent concentration of stress and prevent damage to the locking portion.

[Brief description of drawings]

FIG. 1 is a front view of a penetrating rod according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front view of an extension rod.

FIG. 4 is a side view of the penetration tester.

FIG. 5 is a sectional view of the chuck unit showing a state in which the penetrating rod according to the present invention is held.

[Explanation of symbols]

1 Penetration rod 2 Body shaft 3 Penetration body 4 Male thread 5 Locking part 6 Extension rod 7 Female thread 8 ………… 9 ………… 10 Penetration testing machine 11 frames 12 loading platform 13 motor 14 chains 15 Chuck unit 16 weights 17 hanging 18 sprockets 19 Input axis 20 Torque detector 21 Mounting plate 22 Bearing case 23 Bottom sleeve 24 sprockets 25 Relay sleeve 26 Guide sleeve 26a storage hole 27 steel balls 28 springs 29 Sliding sleeve

   ─────────────────────────────────────────────────── ─── Continued front page       (56) References Fukui Kaihei 4-78321 (JP, U)                 Actual Kaihei 1-118604 (JP, U)                 Actual development Sho 48-1701 (JP, U)                 Actual Kaihei 5-77390 (JP, U)

Claims (3)

(57) [Claims] 1. A loading platform that can be moved up and down along a frame, and an inner hole that is rotatably arranged on the loading platform and penetrates the entire length of the loading platform so that the loading platform always projects into the inner hole.
A chuck unit having an engagement means provided, a drive unit for rotating the chuck unit, said tea
Penetration test with a penetration rod held by a lock unit
In the tester, the penetrating rod has a main body shaft portion formed of a shaft-shaped member that can be inserted through the inner hole of the chuck unit, and the penetrating body is attached to one end of the main body shaft portion and the other end is attached to the main body shaft portion. An extension rod is connectable, and the main body shaft portion is engageable with the engaging means in the chuck unit at a position where the other end of the main body shaft portion projects from the inner hole of the chuck unit, and Long groove-like locking part
A penetration testing machine characterized by being equipped with . 2. A plurality of locking parts are provided by equally dividing the outer circumference of the main body shaft part.
Penetration test according to claim 1, characterized in that the location
Machine . 3. The penetration according to claim 1 or 2, wherein the engaging portion has an arcuate cross-sectional shape, and the engaging means is a steel ball engaging with the engaging portion. Testing machine .