JP2001323769A - Joint of drilling rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint that can be fully applied to the flexible joint of a drilling rod that is used in the ground and can transfer a large compression load, pull, and rotary force between drilling rods with simple structure. SOLUTION: A flexible structure body 4 includes an annular box 10 that is fitted to the outer periphery of a connection shaft part 3 so that it can travel freely in the direction of an axial line, and an annular retainer 11 that is fitted to and fixed to the outer periphery of the connection shaft part 3 and retains a box 10, a cup part 2 is detachably connected to the outer periphery of the box 10 while it receives the box 10 and the retainer 11 inside, and the connection shaft 3 and the box 10 can be subjected to angle displacement within a specific angle range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boring rod joint, and more particularly, to a flexible joint in which a boring rod is not subjected to a bending load when excavating a curved hole.

[0002]

2. Description of the Related Art In boring work, it may be required to excavate a curved hole. In such a case, if a normal boring rod whose tool joint is simply screwed is used, a large repeated bending load will be applied to the tool joint, which may cause a boring rod breakage accident due to fatigue failure. Many.

In order to perform a curved excavation, a flexible joint may be used as a tool joint of a boring rod. However, if a universal joint generally used for a power transmission joint is applied as a flexible joint, its components will be exposed, so that it is not suitable for excavation in the soil. Further, such a universal joint has a complicated structure, and cannot withstand a large compression, tensile load, or rotational force in boring excavation. Moreover, they have a short life, are expensive, and are not practical.

[0004]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above technical background, and has the following objects. An object of the present invention is to provide a joint which can be sufficiently used as a flexible joint of a boring rod used in soil. A further object of the present invention is to provide a joint which can transmit a large compressive load, a tensile load, and a rotational force between boring rods with a simple structure and has excellent durability.

[0005]

The present invention employs the following means to achieve the above object. That is, the present invention relates to a joint for connecting two boring rods, wherein the cup portion is provided at one end of the boring rod, and the cup portion is provided at the other end of the boring rod. And a connecting shaft portion inserted into the boring, wherein a flexible structure for connecting the two boring rods so as to be angularly displaceable is included between the cup portion and the connecting shaft portion. At the rod joint.

The flexible structure has a mechanism for transmitting an axial force in the pulling direction between the two boring rods and a mechanism for transmitting an axial force in the compression direction as separate mechanisms.

[0007] More specifically, the flexible structure is, more specifically, an annular box movably fitted in the axial direction on the outer periphery of the connecting shaft portion, and fitted and fixed on the outer periphery of the connecting shaft portion. An annular retainer for holding a box, wherein the cup portion is removably coupled to an outer periphery of the box in a state in which the box and the retainer are received inside, and the connection shaft portion and the box have a predetermined shape. The box and the retainer are capable of angular displacement in an angular range, and each have a fitting surface capable of transmitting rotational torque to each other, and the box and the retainer are in surface contact with each other following the angular displacement,
And a contact surface capable of transmitting an axial force in a pulling direction between the two boring rods, the connecting shaft portion and the cup portion making a surface contact following the angular displacement, and The boring rod has a contact surface capable of transmitting an axial force in the compression direction to each other.

Each fitting surface of the connecting shaft portion and the box is defined by a polygonal cross section, and the fitting surface of the box has an inclined surface whose fitting cross-sectional area gradually increases from an intermediate portion to both end portions. It has become. Further, a contact surface between the box and the retainer, and a contact surface between the connection shaft portion and the cup portion are each defined by a spherical surface.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial sectional view showing a boring rod joint according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. The joint 1 includes a cup 2 provided at one end of the boring rod R.
And a connecting shaft 3 provided at the other end of the boring rod R and inserted into the cup 2. A flexible structure 4 is included between the cup 2 and the connecting shaft 3. I have. In this embodiment, the cup portion 2 and the connection shaft portion 3 are separately formed from the tube portion 5 of the boring rod R, and are joined to the tube portion 5 by friction welding. S is
The joining surface is shown.

FIG. 3 is a plan view of the connecting shaft 3, FIG. 4 is a sectional view taken along line BB of FIG. 3, and FIG. 5 is a sectional view taken along line CC of FIG. The connecting shaft portion 3 includes a base portion 6 having the same diameter as the tube portion 5 of the boring rod R, a prism portion 7 extending from the base portion 6, and a column portion 8 extending from the prism portion 7. The prism portion 7 has a square cross section in the illustrated example, but is not limited to this, and may have another polygonal cross section. The cylindrical portion 8 is provided with a pin hole 22, and the distal end surface of the cylindrical portion 8 is formed as a convex spherical surface 9. On the other hand, the bottom surface (rear surface) of the cup portion 2 is formed as a concave spherical surface 16 which abuts against the convex spherical surface 9 and forms a spherical pair (see FIG. 1).

An annular box 10 and an annular retainer 11 for holding the box are fitted to the connecting shaft 3. The box 10 is fitted to the prism 7 of the connecting shaft 3 so as to be movable in the axial direction. 6 is an axial sectional view of the box 10, FIG. 7 is a view taken along a line DD in FIG. 6, and FIG. 8 is a view taken along a line EE in FIG. The box 10 is fitted to the prism 7 by a fitting hole 12 having the same cross-sectional shape as the prism 7 of the connecting shaft 3, that is, a square cross section. It is possible.

The fitting surface defined by the inner periphery of the fitting hole 12 is inclined surfaces 14, 15 whose fitting sectional area gradually increases from the intermediate portion 13 to both ends. The portion 3 can be angularly displaced within the range of the inclination angles of the inclined surfaces 14 and 15. A screw portion 17 for coupling to the inner periphery of the cup portion 2 is provided on the outer periphery of the box 10.
Are formed. Further, the front end surface of the box 10 is formed as a convex spherical surface 18, and an outwardly facing annular step 19 is formed at the rear end. A cylindrical flexible cover 20 is fixed between the annular step portion 19 and the connection shaft portion 3 (see FIG. 1), and oils and fats 21 for lubrication are sealed in a space sealed by the cover 20. Have been.

The retainer 11 is fitted to the column 8 of the connecting shaft 3 and is fixed by a pin 23 inserted into a pin hole 22. The rear end face of the retainer 11 is formed as a concave spherical surface 24 that abuts against the convex spherical surface 18 of the box 10 and forms a spherical pair. As is apparent from the above description, the flexible structure 4 has the box 10 and the retainer 11 as main components, and furthermore, the form in which the box 10 and the connecting shaft 3 are fitted to each other, and the contact between the box 10 and the retainer 11. The contact form and the contact form between the connecting shaft 3 and the cup 2 are included.

Next, the operation of the above embodiment will be described. The two boring rods R, R
The cups 2 are connected to each other by connecting the cups 2 to the outer peripheries thereof with the screw portions 17. Box 10 in this state
And the retainer 11 is received inside the cup part 2, and the annular step 19 of the box 10 engages with the end face of the cup part 2. The rotational torque is transmitted between the two boring rods R via the box 10 and the connecting shaft 3.

When an axial force acts in the pulling direction between the two boring rods R, the convex spherical surface 18 of the box 10 comes into contact with the concave spherical surface 24 of the retainer 11, and the axial force is reduced by the box 10 and the retainer. 11 to each other. In this state, even if an angular displacement occurs between the connecting shaft 3 and the box 10, the box 10 and the retainer 11
Are in surface contact with the spherical surfaces 18 and 24,
It follows the angular displacement.

On the other hand, when an axial force in the compression direction acts between the two boring rods R, R, the convex spherical surface 9
And the concave spherical surface 16 of the cup 2 abuts, and the axial force is transmitted directly from the cup 2 to the connecting shaft 3. In this state, even if an angular displacement occurs between the connecting shaft 3 and the box 10, the cup 2 and the connecting shaft 3 follow the angular displacement because they are in surface contact with the spherical surfaces 9 and 16. Will be.

According to the joint as described above, the flexible structure 4 is included between the cup 2 and the connecting shaft 3 and is not exposed to the outside. It is sufficiently applicable as a boring rod flexible joint and does not cause excavation trouble. Further, since the rotational torque is transmitted by fitting the box 10 to the connecting shaft 3, a large rotational torque can be transmitted.

A mechanism for transmitting the axial force in the pulling direction (abutment between the box 10 and the retainer 11) and a mechanism for transmitting the axial force in the compression direction (the connection between the cup 2 and the connecting shaft 3). Since the abutment) is a separate mechanism, it is possible to take an optimal form for transmitting the axial force and to endure a large axial force. For this reason, not only rotation, compression, and pulling force but also impact force and vibration force can be transmitted. Further, the whole structure is simple, the pin 23 can be disassembled only by extracting it, and no special tool is required, so that maintenance is easy.

Next, an example of boring using a boring rod having the above joint will be described. FIG.
Is an example of widening the existing pipeline 50 having a curved portion,
(A) shows a case where the hole 51 widened by pulling the boring rod R inserted into the existing pipeline 50 is excavated.
(B) shows a case where the hole 51 widened by pushing the boring rod R into the existing pipeline 50 is excavated.

FIG. 10 is a plan view showing an example of a bit used, and FIG. 11 is a sectional view taken along line FF of FIG. The bit 30 includes a cylindrical main body 31 and a plurality of wings 32 extending radially from the main body 31, and the wings 32 are provided with a carbide tip 33. Further, screw portions 34, 35, 36 are formed on the inner periphery of the front end portion and the inner periphery of the rear end portion of the main body 31, respectively.

FIG. 12 shows the connection between the leading boring rod R and the bit 30. FIG. 12A shows the case of the pulling work, in which the screw portion 36 of the bit 30 is screwed to the cup portion 2 of the leading boring rod R. In addition, a bit adapter 37 is screwed to the screw portion 34 of the bit 30, and a swivel joint 38 is coupled to the bit adapter 37.
Further, a water pipe 40 for sending a liquid for cooling the bit is connected via the adapter 39.

FIG. 12 (B) shows the case of the push-in operation, in which the bit 30 is turned in the opposite direction to the case of the pull-in operation, and the adapter 41 is screwed to the screw portion 34 of the bit 30, and the leading boring rod The R cup portion 2 is screwed. A bit adapter 37, a swivel joint 38, an adapter 39, and a water pipe 40 are sequentially connected to the screw portion 35 of the bit 30 in the same manner as in the case of the pulling work.

Referring to FIG. 9 again, in the case of the pulling work (A), the boring rod R is inserted into the existing pipeline 50 while successively extending, and the boring rod R is inserted into the leading boring rod R in a vertical shaft (not shown) with reference to FIG. The bit 30 is mounted as described above. Then, the boring machine 53 installed in the shaft 52 rotates and pulls (pulls out).
Is transmitted to the bit 30 via the boring rod R to excavate. At this time, even if there is a curved portion in the existing pipeline 50, the boring rod R is connected by the flexible joint 1, so that the boring rod R bends following the curved portion shape and no bending force is applied.

In the case of the push-in operation (B), the boring machine 53 transmits the rotational force and the compressive force (push-in force) to the bit 30 via the boring rod R and excavates. Also in this case, even if the existing pipeline 50 has a curved portion, the boring rod R bends following the curved portion shape and no bending force is applied.

FIG. 13 shows an operation process for one boring rod in the case of pulling work. When the excavation of one boring rod is completed after the start of excavation shown in (A) (B), the rod clamp 54 and the rod breaker 55 of the boring machine 53 are operated in the same manner as a normal boring method, and the boring rods are connected to each other. The connection screw 17 and the connection screw 17 (the screw portion 17 shown in FIG. 1) with the boring machine 53 are released (C). Then, one boring rod R is extracted, and the process of entering the next excavation is repeated (D).

Thus, a boring rod having a joint according to the present invention can be handled in the same manner as a conventional boring rod. If it is effective to hit the bit to improve the excavation speed,
By attaching a striking mechanism to the boring machine 53, FIG.
A hit can be added in the state of (A) or (B).

[0027]

As described above, according to the present invention, the present invention can be put to practical use as a flexible joint for a boring rod used in soil. In addition, a simple structure allows a large compressive load, a tensile load, and a rotational force to be transmitted between the boring rods, and is a joint excellent in durability.

[Brief description of the drawings]

FIG. 1 is an axial sectional view showing a joint of a boring rod according to the present invention.

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

FIG. 3 is a plan view of a connecting shaft portion.

FIG. 4 is a view taken along line BB of FIG. 3;

FIG. 5 is a sectional view taken along line CC of FIG. 3;

FIG. 6 is an axial sectional view of the box.

FIG. 7 is a view taken along the line DD in FIG. 6;

FIG. 8 is a view taken in the direction of the arrows EE in FIG. 6;

FIG. 9 is a diagram showing an example of a boring operation using a boring rod having a joint according to the present invention.

FIG. 10 is a plan view showing an example of bits used.

FIG. 11 is a sectional view taken along line FF of FIG. 10;

FIG. 12 is a diagram showing a connection between a leading boring rod and a bit.

FIG. 13 is a diagram showing an operation process for one boring rod in the case of pulling work.

[Explanation of symbols]

 1: Joint 2: Cup part 3: Connection shaft part 4: Flexible structure 7: Prismatic part 8: Cylindrical part 9: Convex spherical surface 10: Box 11: Retainer 12: Fitting hole 13: Middle part 14: Inclined surface 15 : Inclined surface 16: concave spherical surface 18: convex spherical surface 20: flexible cover 22: pin hole 23: pin 24: concave spherical surface 30: bit 50: existing pipeline 53: boring machine R: boring rod

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor: Yutaka Kaneko 1-29-15-1 Chuo, Nakano-ku, Tokyo Inside Minken Kogyo Co., Ltd. (72) Inventor Tetsuya Endo 1-29-15 Chuo, Nakano-ku, Tokyo (72) Inventor Takeshi Manri 1-29-15 Chuo, Nakano-ku, Tokyo Inside Minken Co., Ltd.

Claims (6)

[Claims] 1. A joint for connecting two boring rods, comprising: a cup provided at one end of the boring rod; and a cup provided at the other end of the boring rod. A boring rod, comprising: a connecting shaft portion to be inserted; and a flexible structure for connecting the two boring rods so as to be angularly displaceable between the cup portion and the connecting shaft portion. Joint. 2. The flexible structure has a mechanism for transmitting an axial force in a tensile direction between the two boring rods and a mechanism for transmitting an axial force in a compression direction as separate mechanisms. The joint of a boring rod according to claim 1, wherein 3. The flexible structure comprises: an annular box fitted to the outer periphery of the connecting shaft portion so as to be movable in the axial direction; and a fitting and fixed to the outer periphery of the connecting shaft portion to hold the box. An annular retainer, wherein the cup portion is detachably coupled to an outer periphery of the box with the box and the retainer received therein, and the connection shaft portion and the box have an angle within a predetermined angle range. The box and the retainer are displaceable and each have a fitting surface capable of transmitting rotational torque to each other, the box and the retainer are in surface contact following the angular displacement, and a pulling direction is provided between the two boring rods. The coupling shaft portion and the cup portion are in surface contact with each other following the angular displacement, and between the two boring rods. Joint boring rod according to claim 1, wherein the axial force of the compression direction has a mutually transferable contact surface. 4. The boring rod joint according to claim 3, wherein each fitting surface between said connecting shaft portion and said box is defined by a polygonal cross section. 5. The boring rod joint according to claim 4, wherein the fitting surface of the box is an inclined surface whose fitting cross-sectional area gradually increases from an intermediate portion to both end portions. 6. A contact surface between the box and the retainer,
6. The boring rod joint according to claim 3, wherein a contact surface between the connection shaft portion and the cup portion is defined by a spherical surface.