JP2582047B2 - Drilling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling device for drilling underground, ground and rock by applying a rotary impact in civil engineering construction work.

[0002]

2. Description of the Related Art In a conventional drilling machine of this type, a rod is inserted into a casing, a bit is attached to the tip of the rod, and the upper end of the rod is hit and rotated, and the bit is rotated and hit against rock and ground. Drilling. In this conventional drilling device, the bit is sized so as to fit in the casing, so that the bit can be moved in and out of the casing by the rod, and the bit can be raised and recovered through the casing. For this reason, it was difficult to drill the bit larger than the casing inner diameter and larger than the casing outer diameter. Holes large enough to insert the casing and widened holes could not be formed, resulting in poor drilling efficiency. Further, there is a drilling device in which a bit having a diameter larger than the outer diameter of the casing is attached to the tip of the rod in advance. However, the bit rod cannot be pulled up through the casing and collected. When the casing was buried while being left under the ground, the bits could not be collected.

[0003] An eccentric drilling tool disclosed in Japanese Patent Publication No. 51-25101 is an example of a drilling device that improves this point.
In this tool, a pilot bit smaller than the inside diameter of the casing is attached to the tip of the rod in the casing, and a guide for preventing lateral movement of the rod is provided at the lower part of the casing, and the rod part between the guide and the pilot bit is eccentric. The reamer bit is rotatably attached to the outside of the eccentric rod portion, and an engaging portion is provided at a rear portion of the pilot bit and a front portion of the reamer bit to rotate the reamer bit. When the rod is rotated in the drilling direction, the reamer bit does not rotate or rotates less due to the resistance to the drilling, the pilot bit and the reamer bit rotate relatively, and the engaging portion between the pilot bit and the reamer bit is rotated. The reamer bit is forcibly rotated together with the pilot bit where it is integrated. At the time of this engagement, the outer peripheral end of the reamer bit is made to protrude outward from the outer diameter of the casing, so that the reamer bit can be drilled with a diameter larger than the outer diameter of the casing by rotating the rod in the drilling direction. Things. To raise the bit, rotate the rod in the direction opposite to the drilling direction. The reamer bit comes to rest due to the resistance to the hole wall, and the reamer bit rotates around the relatively eccentric rod portion, so that the reamer bit is in a phase state that can be accommodated in the casing. When the rod is pulled up in this phase state, the pilot bit and the reamer bit can be pulled up and collected in the casing.

However, in the tool disclosed in this publication, when the pilot bit and the reamer bit are raised, when the resistance of the underground hole wall acting on the reamer bit is small, the friction between the eccentric rod outer periphery and the fitting surface of the reamer bit is smaller. As it grows, the reamer bit rotates with the rod
The reamer bit does not relatively rotate around the eccentric rod portion, so that the phase of the reamer bit cannot be accommodated in the casing, and the pilot bit and the reamer bit cannot be lifted and collected.

[0005]

The problem to be solved by the present invention is to solve these problems of the prior art and to allow a part of the bit to be widened so that a hole having a diameter larger than the casing can be formed. Another object of the present invention is to provide a drilling device in which a bit can be forcibly stored in a casing and the bit is reliably collected.

[0006]

According to the structure of the present invention which solves the above problems, a rod is inserted into a casing, a pilot bit having a diameter smaller than the inner diameter of the casing is attached to the tip of the rod, and the pilot bit is attached to the casing. In a drilling machine that drills the ground with the pilot bit at the tip by rotating and hitting the rod while being located below, a guide that contacts the inner surface of the casing at the bottom of the rod and prevents lateral movement of the rod is provided. The rod part between the guide and the pilot bit is eccentric and has a circular cross section. At a predetermined rotation phase, a part of the peripheral end is widened outward from the outer periphery of the casing outside the eccentric part and another required part A reamer bit that fits inside the casing in the rotation phase is rotatably inserted, and the reamer bit rotates against the rotation of the pilot bit in the drilling direction. Rotational engagement parts for rotating the reamer bit by engaging the phase in the expanded phase are provided at the rear part of the pilot bit and the front part of the reamer bit, and a forcible return cam is protruded at the lower end of the casing, at the rear part of the reamer bit. The drilling device according to claim 1, further comprising an engagement step for engaging with the reamer bit forced return cam.

[0007]

According to the present invention, when the rod is rotated in one direction in a state where the reamer bit is exposed from the lower end of the casing in the ground, the reamer bit does not rotate much due to the resistance against the hole wall of the ground hole, and the pilot bit and the rod are not rotated. The eccentric part of rotates. When the pilot bit rotates, the engaging portion between the rear part of the pilot bit and the front part of the reamer bit is locked, the torque of the pilot bit is transmitted to the reamer bit, and the reamer bit rotates with the pilot bit rod. In addition, the phase of the reamer bit at this time is such that one peripheral end of the reamer bit protrudes outward from the outer diameter of the casing, so that the hole diameter that can be drilled by rotation of the reamer bit becomes larger than the outer diameter of the casing. The movement and deflection in the lateral direction (radial direction) due to the rotation impact of the rod are prevented by the guide.

Next, when the reamer bit is not used or when the pilot bit and the reamer bit are stored in the casing,
To raise the rod, rotate the rod in the opposite direction.If there is sufficient resistance between the reamer bit and the hole wall, the reamer bit does not rotate much due to the resistance between the hole and the pilot bit. The pilot bit and the reamer bit rotate relative to each other, and the reamer bit rotates around the eccentric portion of the rod, so that the phase is such that the reamer bit is housed in the casing. When the rod is pulled up in this state, the pilot bit and the reamer bit are lifted. The pilot bit and the reamer bit are both housed in the casing and can be pulled up with the pulling up of the rod.

If the resistance between the reamer bit and the drilled hole wall is weak and the friction of the rotating surface (fitting surface) between the reamer bit and the eccentric rod portion is larger, the rod
When the pilot bit is reversely rotated, the frictional force causes the reamer bit to rotate together with the rod / pilot bit in the same direction, so that the reamer bit does not come into the phase accommodated in the casing. In this case, when the rod is slightly lifted upward and the rod is slightly rotated in the opposite direction, the reamer bit forced return cam at the lower end of the casing engages with the engagement step of the reamer bit slightly raised together with the rod, and the reamer bit of the reamer bit is engaged. Stop rotation and rotate only the rod. The reamer bit rotates relatively around the eccentric rod, and can be in a phase that can be stored in the casing. If the rod is pulled up in this state, the pilot bit and the reamer bit are pulled up through the casing and collected.

As another bit raising method in the above case, the rod is slightly lifted upward without rotating the rod / pilot bit, and the casing is rotated in the drilling direction. Then, the reamer bit forcibly returning cam at the lower end of the casing and the engagement step portion of the reamer bit slightly raised together with the rod are engaged to apply rotation to the reamer bit, thereby achieving a phase in which the reamer bit can be stored in the casing. If the rod is pulled up in this state, the pilot bit and the reamer bit are pulled up through the casing and collected.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view showing a drilled state of a main part of the embodiment, FIG. 2 is a partially cutaway front view showing a state where a reamer bit is taken in the main part of the embodiment, and FIG. 3 is a reamer of a main part of the embodiment. FIG. 4 is a left side view of a main part in the state of FIG. 1, FIG. 5 is a left side view of a main part in the state of FIG.
FIG. 6 is a left side view of the main part in the state of FIG. 3, and FIG.
FIG. 8 is a sectional view taken along the line BB of FIG. 2, and FIG. 9 is a sectional view taken along the line CC of FIG. In the drawing, 1 is a casing, 2 is a rod, 2a is the axis of the rod, 3 is a pilot bit attached to the tip of the rod, 4 is a guide for preventing lateral movement attached to the lower part of the rod 2, and 5 is a rod 2 A lower eccentric portion, 5a is the center of the eccentric portion 5, 6 is a reamer bit, 7 is a front protrusion of the reamer bit 6 having an engaging portion 7b, 7a and 7b are engaging portions, and 8 is a lower end of the casing 1. The provided reaming bit forcibly returning cam, 9 is an engagement step portion which engages with the cam, 10 is a water injection hole drilled in the center of the rod 2, 1
1 is a cutout portion of the reamer bit 6, 12a and 12b are cutting blades of each bit, and 13 is a step preventing movement of the guide 4.

In this embodiment, when a drilling operation is performed underground, on the ground, on the bedrock, or the like, the state is as shown in FIGS. That is, the rod 2 is rotated clockwise, the pilot bit 3 rotates clockwise, and the engaging portion 7a at the rear of the pilot bit 3 engages with the engaging portion 7b of the protruding portion 7 at the front of the reamer bit 6. Then, with the rotation of the pilot bit 3, the reamer bit 6 is rotated via the engaging portions 7a and 7b. The phase reamer bit 6 in this state is shown in FIGS.
As shown in the figure, one peripheral end of the reamer bit 6 protrudes from the outer periphery of the casing 1. Therefore, when the reamer bit 6 is rotated in this state, the reamer bit 6 drills in the ground with a diameter larger than the outer circumference of the casing 1.

Next, when taking in the reamer bit, if the rotation of the rod 2 is rotated to the left, the rotation of the reamer bit 6 is reduced when the resistance from the hole wall acts on the reamer bit 6 greatly. The engagement of the joints 7a, 7b is released, and the reamer bit 6 relatively rotates around the eccentric portion 5 of the rod 2, and from the state of FIGS.
The state changes to 5, 8 reamer bit capture state. Further, when the reamer bit 6 rotates, the state shown in FIGS. 6 and 9 is reached, and the reamer bit 6 is in the phase state accommodated in the casing 1. When the rod 2 is pulled up in this state, the pilot bit 3 and the reamer bit 6 are accommodated in the casing 1. ,
The casing can be lifted and pulled out.

Here, when the resistance of the hole wall acting on the reamer bit 6 is small and the rotational friction of the rod portion eccentric to the reamer bit 6 is larger, when the rod 2 is rotated reversely, the large friction causes the reamer bit 6 to rotate. Rod 2
Rotate with. Here, when the rod 2 is slightly pulled up, the engaging step 9 at the rear of the reamer bit 6 is engaged with the reamer bit forced return cam 8 at the lower end of the casing. Since the underground hole wall and the casing 1 having a large resistance do not rotate, the reamer bit 6 engaged with it does not rotate, and only the eccentric rod portion 5 rotates, so that the reamer bit 6 advances and retreats in the radial direction due to the eccentricity. The reamer bit 6 can be set to a phase that can be stored in the casing 1. If the rod 2 is pulled up in a state where the reamer bit 6 can be stored in the casing, the pilot bit 3 and the reamer bit 6 can be pulled up and collected.

The casing can be buried underground.

[0016]

As described above, according to the present invention, the reamer bit is attached to the outer periphery of the eccentric portion of the rod, and the reamer bit is rotated at the engaging portion with the pilot bit so that the outer peripheral end of the reamer bit comes out of the outer diameter of the casing. Since it is possible to maintain the phase of the closed state and the state of being housed in the casing, the drilling by the bit can be drilled with a diameter larger than the outer diameter of the casing, and the drilling work efficiency is improved. Further, the bit widened by the reamer bit forcibly returning cam at the lower end of the casing and the engaging step portion is stored in the casing in a contracted state and the bit can be pulled out, so that the bit can be reliably collected.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a drilled state of a main part of an embodiment.

FIG. 2 is a partially cutaway front view showing a reamer bit capturing state of a main part of the embodiment.

FIG. 3 is a partially cutaway front view showing a state where a reamer is pulled out of a main part of the embodiment.

FIG. 4 is a left side view of a main part in the state of FIG. 1;

FIG. 5 is a left side view of a main part in the state of FIG. 2;

FIG. 6 is a left side view of a main part in the state of FIG. 3;

FIG. 7 is an explanatory sectional view taken along the line AA of FIG. 1;

FIG. 8 is a sectional view taken along the line BB of FIG. 2;

FIG. 9 is a cross-sectional explanatory view taken along the line CC in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Rod 2a Shaft center 3 Pilot bit 4 Guide 5 Eccentric part 5a Center 6 Reaming bit 7 Projection part 7a Engagement part 7b Engagement part 8 Cam 9 Engagement step part 10 Water pouring hole 11 Notch part 12a Cutting blade 12b Cutting blade 13 Movement prevention step

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichi Yoshida 2-3 Kandajimachi, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (72) Inventor Hiroyuki Watanabe 98-10 Oku Tokuhisa, Chikugo-shi, Fukuoka (72) Inventor Hirokazu Nakazawa 18-14 Futabacho, Jobandaira, Matsudo-shi, Chiba (56) References Japanese Utility Model Application Hei 6-24088 (JP, U)

Claims (1)

(57) [Claims] 1. A rod is inserted into a casing, a pilot bit having a diameter smaller than the inner diameter of the casing is attached to a tip of the rod, and the rod is rotationally hit with the pilot bit positioned below the casing to form a tip. In a drilling machine that drills the ground with a pilot bit, a guide is attached to the lower part of the rod to contact the inner surface of the casing to prevent lateral movement of the rod, and the rod part between the guide and the pilot bit is eccentric. A reamer bit having a circular cross-section and having a shape in which a part of its peripheral end is widened outward from the outer periphery of the casing at a predetermined rotation phase and fits inside the casing at another required rotation phase outside the eccentric portion is rotatable. The reamer bit is engaged by rotating the pilot bit in the drilling direction and engaging Rotational engagement parts to be provided are provided at the rear part of the pilot bit and the front part of the reamer bit, and a reamer bit forced return cam is protruded at the lower end of the casing, and an engagement step is provided at the rear part of the reamer bit to engage with the reamer bit forced return cam. A drilling device characterized by the above-mentioned.