JPH0758032B2 - Drill pipe connecting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe connecting device,
In particular, the present invention relates to a connecting device for excavating pipes that sequentially excavate pipes to advance underground.

[0002]

2. Description of the Related Art A boring operation or the like is carried out by sequentially connecting excavation pipes having a constant length and excavating in the ground. And
Generally, the connection between the drill pipes differs depending on whether the drill pipe has a small diameter or a large diameter. That is, when the digging pipe has a small diameter, a male screw is formed at the tip of the digging pipe and a female screw is formed at the rear end of the digging pipe. Link. If the drill pipe has a large diameter, a flange is formed on the front and rear ends of the pipe, and the flanges on the front and rear ends of the pipes are connected with bolts so that the pipes are coaxially aligned. Connect to. Alternatively, a spline or polygonal column joint, for example, a male hexagonal pin is formed at one end of a digging pipe, and a hexagonal box is formed at the other end to fit the digging pipes together.

After the fitting, a pin or the like is inserted into the fitting portion from the outside of the drill pipe to maintain the axial force.

[0004]

However, although the pipes can be connected to each other by means of screws in a short time, an excessive torque is required to remove the pipes after the excavation. Therefore, there is a problem that it takes time to remove the drill pipes from each other. Further, in the case of flange connection, there is a problem that it takes a long time to attach and detach because the flange is tightened with several bolts to be connected.

On the other hand, when connecting a plurality of juxtaposed multi-axis drilling pipes at one time, it takes more time for positioning and centering and is technically difficult than connecting a single-axis drilling pipe. Therefore, automation was impossible. Also, in this case, using a conventional connecting method in which a male hexagonal pin is formed at one end of the drill pipe and a female hexagonal box is formed at the other end to fit the drill pipes together Of the pipes, for example, if one digging pipe does not fit because the uneven parts of the hexagons do not fit,
Adjust by rotating the pipe that does not fit. However, when this digging pipe is rotated, the other digging pipes are also rotated, so that there is a disadvantage that the other digging pipes do not fit. For this reason, it is necessary to change the rotational position many times to find a position where the multiple shafts are fitted at the same time.

Further, the hexagonal joint or the ordinary spline joint has a drawback that the manufacturing cost becomes high because the cutting process must be performed for each tooth.
The present invention has been made in view of the above circumstances, and it is possible to manufacture at a low cost, connect and disconnect the drill pipes in a short time, and provide a plurality of juxtaposed multi-axis drill pipes. Another object of the present invention is to provide a drill pipe connecting device that can be easily attached and detached.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a drilling pipe for digging into the ground while sequentially connecting unit drilling pipes of a fixed length and applying rotation and feed by a driving device. In the coupling device, a male shaft having a male involute spline formed on one end of the drill pipe, and a female shaft having a female involute spline formed on the other end of the drill pipe. It is characterized in that the male and female shafts are engaged with each other by engaging the involute splines with each other, and the rotational force is transmitted to the drill pipes.

[0008]

According to the present invention, first, the male involute spline formed at one end of the drill pipe is fitted to the female involute spline formed at the other end of the connecting pipe. The involute spline is a kind of gear and is composed of a female internal gear and a male external gear fitted to the female internal gear. Therefore, the number of teeth can be set to be several times as large as that of the conventional spline, so that the positions of the teeth can be easily aligned and the fitting can be easily performed. Further, since the involute spline teeth are processed by the gear cutting device, the total number of teeth can be uniformly cut with high accuracy, and the processing cost can be reduced.

Further, at the time of fitting, the tooth irregularities contact each other,
Even if the concavo-convex parts of the involute splines do not match, by forming a chamfer on both sides of each tip of the male and female involute splines, pushing the male involute spline into the female involute spline will result in a male involute spline. Since the tapered surface of the spline teeth presses the tapered surface of the female involute spline, and the male involute spline is pushed along the tapered surface of the female involute spline,
The drill pipes can be fitted together. Therefore, when connecting the multi-axis drill pipes, it is advantageous because no alignment is required.

Further, since the digging pipe is fitted with the involute spline, the digging pipes can be easily removed from each other simply by pulling it out. Therefore, it is possible to connect and disconnect the drill pipes in a short time, and it is possible to easily connect a plurality of juxtaposed multiaxial pipes by the effect of the involute spline.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a drill pipe connecting device according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a drill pipe connecting device 10 according to the present invention. Upper and lower drill pipes 1 connected by this pipe connecting device 10.
The reference numerals 2 and 12 are formed to have a constant length, and a female shaft 14 as a connecting member is fixed to the lower end of the digging pipe 12 on the upper side in the drawing. The female shaft 14 is formed in a tubular shape and arranged coaxially with the drill pipe 12, and an involute spline 16 shown in FIG. Further, as shown in FIG. 3, the involute spline 16 has chamfered tapered surfaces 16B and 16B formed on both sides of the tip of each tooth 16A, 16A.

The involute spline 16 is formed on the axis of the digging pipe 12 shown in FIG. 1, and the involute spline 20 formed on the male shaft 18 as a connecting member is shown in FIG. Is splined to. As a result, the drill pipe 12 on the upper side in the figure
Is transmitted to the drill pipe 12 on the lower side in the figure. The male shaft 18 is fixedly disposed coaxially with the drill pipe 12 on the lower side in the drawing. In addition, the involute spline 2
Similar to the involute spline 16, tapered surfaces are formed on both sides of the tip of each tooth of 0. Further, the packing 22 prevents the injection liquid from entering the connecting portion when the injection liquid such as cement milk is ejected from the tip of the bit 42 shown in FIG. It is provided to prevent it.

On the other hand, as shown in FIG. 1, an involute spline 24 is formed on the outer peripheral portion of the lower end of the female shaft 14, and square holes 26, 26 ... Are shown in FIG. 4 in the lower part of the involute spline 24. Thus, the openings are formed at 45 ° intervals. This hole 26 is the central axis 1 of the male shaft 18.
The taper shape is formed toward 8a. Also, each hole 2
6, 26 ... have connection blocks 28, 2 having a substantially trapezoidal cross section.
8 are mounted slidably in the radial direction of the female shaft 14.

An annular groove 30 is formed on the outer peripheral portion of the male shaft 18.
Is formed. The groove 30 is provided with the connecting blocks 28, 28, ... When the male shaft 18 is spline-fitted to the female shaft 14.
Is formed at a position corresponding to. As shown in FIG. 1, the side surface of the groove 30 is formed with a tapered surface so that it can be locked with the tapered surface of the connecting block 28. The female shaft 1
A cylindrical body 32 is inserted into the outer periphery of the cylindrical body 4, and the cylindrical body 32 is attached so as to be vertically movable in the axial direction of the digging pipe 12 as indicated by an arrow in the figure. Further, an involute spline 34 is formed on the inner peripheral surface of the cylindrical body 32. The involute spline 34 is formed in the axial direction of the digging pipe 12 and has an uneven shape so as to be spline-fitted with the involute spline 24 of the female shaft 14. The involute splines 24 and 34 are provided to prevent the cylindrical body 32 from rotating due to the resistance of earth and sand or the like and damaging the packing.

On the outer periphery of the female shaft 14, a packing 3 as a stopper for the cylindrical body 32 and as a sealing material for preventing muddy water from entering.
6, 39 are provided, whereby the cylindrical body 32 and the female shaft 14 are held in a sealed state. Further, one end surface of the cylindrical body 32 is connected to the packings 35, 38 provided on the male shaft 18 in a connected state.
Since the cylindrical body 32 and the male shaft 18 are kept in a sealed state, it is possible to prevent muddy water from entering the connecting portion from the outside, and the packing 35 prevents water pressure on the drill pipe 12 on the upper surface of the cylindrical body 32. Since the cylinder 32 is pressed downward in FIG. 1, the cylinder 32 can be prevented from coming off during excavation together with the frictional resistance transmitted to the connecting block 28. Furthermore, the packing 36 is used when the drill pipe 12 is attached or detached.
It has a role of holding the cylindrical body 32 in a state in which 2 is moved upward in the drawing (FIG. 6). That is, when one of the drill pipes 12 is lifted, a part of the connecting block 28 enters the inner diameter storage portion 33 of the cylindrical body 32 due to the tapered surface of the groove 30 of the male shaft 18, and the drill pipe 1
It is possible to attach and detach two or twelve members.

A drill pipe connecting device 10 constructed as described above.
The action of will be described. First, the power pipe swivel 40 of the base machine 38 shown in FIG. 5 is attached with the drill pipe 12 provided with the drill pipe connecting device 10, and a bit 42 that is a drilling blade is provided at the tip to add the drill pipe 12 to cement cement milk. The injection liquid such as is ejected from the tip of the bit 42 to excavate the ground. An auger 44 is attached to the digging pipe 12. Next, the length of one digging pipe 12 is excavated, and then the new digging pipe 12 is connected by the digging pipe connecting device 10 and added.

As shown in FIG. 6, the male shaft 18 is held by the holder 48 so that the drill pipe 12 (lower side in the drawing) used for excavation does not drop into the drill hole 46. Four
It is fixed so that it is located above 6. And the male shaft 18
The digging pipe 12 (upper side in the drawing) is inserted into the involute spline 20 of (1) and the involute spline 16 of the female shaft 14 is spline-fitted to connect the rotational directions. At this time, since the tapered chamfers are formed on both the tip end surfaces of the teeth of the involute splines 16 and 20, as described above, the female shaft 14 is guided and inserted into the male shaft 18 along the respective chamfers. As a result, the involute spline 20 can be easily installed without aligning the fitting portion.
Can be inserted and fitted to the involute spline 16. That is, as shown in FIG. 7A, the tapered surface 20 of the tooth 20A of the involute spline 20 of the male shaft 18 is shown.
B presses the taper surface 16B (shown in FIG. 3) of the teeth 16A of the female involute spline 16, and the male involute spline 20 follows the taper surface 16B of the female involute spline 16 in the figure (b). Since it is pushed in as shown in Fig. 1, there is no need for alignment and the drill pipe 1
2, 12 can be easily spline-fitted to each other.

After fitting the involute spline, a not-shown fork or the like is hooked in the groove 37 of the outer shape of the cylindrical body 32, and the cylindrical body 32 is moved downward from the position shown in FIG. 6 by this fork. When the cylindrical body 32 is moved downward, the inner peripheral tapered surface 32a of the cylindrical body 32 contacts the outer peripheral tapered surface 28a of the connecting block 28, and the outer peripheral tapered surface 28a is pushed by the inner peripheral tapered surface 32a. Block 28
Slide in the direction of the arrow in the figure, that is, in the direction of the central axis 18a (shown in FIG. 4) of the male shaft 18. When the connecting block 28 slides, the inner peripheral portion of the connecting block 28, as shown in FIG.
It is locked in the groove 30 of the male shaft 18 and is coupled in the axial direction. As a result, the axial force between the digging pipes 12, 12 is held and the connection is completed.

When removing the dug pipes 12, 12, the cylindrical body 32 is moved to a position shown in FIG. 6 by a not shown fork or the like, and then the female shaft 14 is pulled out from the male shaft 18. When the female shaft 18 is pulled out, the inner peripheral tapered surface 28b of the connecting block 28 is pushed by the tapered surface of the groove 30,
The connecting block 28 slides in the direction of retracting from the groove 30. As a result, the connection between the drill pipes can be released.

Further, the groove 30 of the male shaft 18 and the connecting block 2
8 is not necessary, so it can be fitted at any position of multiple teeth of the involute spline, and it is easier and shorter than the conventional drill pipe connecting device that requires alignment. Can be done in time. Furthermore, it is possible to similarly connect a plurality of juxtaposed multiaxial pipes.

FIG. 8 shows another embodiment of the axial force holding mechanism for the drill pipes 12, 12 connected to each other. According to FIG.
A pair of through holes 50 formed in the fitting of the drill pipes 12, 12.
The connecting pins 54 and 56 are inserted into 52, and the ends thereof are covered with spring holders 58 and 60 shown in FIG. 9 so that the connecting pins 54 and 56 do not fall out. The pair of through holes 50, 52 are formed by fitting grooves formed in the female shaft 14 and the male shaft 18 by involute spline fitting, and are formed orthogonal to the connecting direction of the drill pipe 12. . As a result, the axial force of the drill pipes 12, 12 can be maintained without using the connecting block 28 and the cylindrical body 32 shown in FIG. The connecting pins 54 and 56 may be polygonal columns or columns.

In the present embodiment, an example of excavating in the vertical direction has been shown, but the present invention is not limited to this and can be used in the case of excavating in the horizontal direction.

[0023]

As described above, according to the drill pipe connecting apparatus of the present invention, a male involute spline is provided at one end of the drill pipe, and a female involute is provided at the other end of the connecting pipe. Since each spline is formed, it can be easily joined without requiring alignment. In addition, even if the concavo-convex parts of the involute splines do not match when mating, if the male involute spline is pushed into the female involute spline,
The male tapered surface of the involute spline teeth presses the tapered surface of the female involute spline, and the male involute spline is pushed along the tapered surface of the female involute spline, so that the pipes can be easily fitted to each other. You can

Therefore, since the structure is simple and the connecting and disconnecting of the excavating pipes can be carried out in a short time, it is possible to easily connect a plurality of juxtaposed multi-axial excavating pipes and to automatically attach and detach them. Is also possible easily. Further, by providing an involute spline in place of the conventional spline, the number of teeth is increased to facilitate fitting, and automatic gear cutting can be performed, so that the processing accuracy is improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a drill pipe connecting device according to the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a perspective view of a main part showing an example of chamfering a tapered tip of a female involute spline.

FIG. 4 is a sectional view taken along the line BB in FIG.

FIG. 5 is an explanatory view showing a state of excavating the underground using a drill pipe connected by a drill pipe connecting device according to the present invention.

FIG. 6 is a cross-sectional view showing an embodiment at the time of attaching and detaching the connecting device for a drill pipe according to the present invention.

FIG. 7 is an explanatory view showing a state where male and female involute splines are inserted and fitted.

FIG. 8 is a cross-sectional view showing another embodiment of the axial force holding mechanism for a digging pipe.

9 is a sectional view of the tank on the line AA in FIG.

[Explanation of symbols]

 10 ... Drill pipe connecting device 12 ... Drill pipe 14 ... Female shaft 16 ... Female involute spline 18 ... Male shaft 20 ... Male involute spline 26 ... Hole 28 ... Connection block 30 ... Groove 32 ... Cylindrical body

Claims (2)

[Claims] 1. A drill pipe connecting device for sequentially connecting unit drill pipes of a constant length and driving and rotating and feeding the drill pipes into the ground, wherein a male pipe is provided at one end of the pipe. A male shaft having an involute spline formed therein, and a female shaft having a female involute spline formed at the other end of the drill pipe, wherein the male and female shaft involute splines are meshed with each other. A connecting device for a drill pipe, characterized in that the two are fitted to each other and a rotational force is transmitted to the drill pipe. 2. The drill pipe connecting device according to claim 1, wherein tapered chamfers are formed on both front end portions of each tooth of the male and female shaft involute splines.