JPH0334493Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a connecting device for a lead pipe laid underground by a pipe burying machine.

BACKGROUND ART Conventionally, as a method for burying small-diameter pipes underground with high precision, the pipe burying methods shown in FIGS. 4 to 6 are known.

In the pipe burying method described above, first, the pipe burying machine 2 installed in the starting bit 1 propels the leading pipe 4 toward the arrival bit 3. A pilot head 5 having a direction control function as shown in FIG. By changing the leading pipe 4
The structure is such that the direction of propulsion can be controlled.

When the pilot head 5 reaches the arrival bit 3, the pilot head 5 is separated from the tip of the leading pipe 4, and the buried pipe 9 is connected to the leading end of the leading pipe 4.
The underground pipe 9 is laid underground by drawing the underground pipe 9 into the ground through the leading pipe 4 by the pipe burying machine 2 as shown in FIG.

Problems to be Solved by the Invention In the conventional pipe burying method described above, a threaded joint is provided at the end of each lead pipe 4, and the lead pipes 4 are successively added using the threaded joint.

For this reason, the operator has to rotate the heavy leading pipe 4 inside the starting bit 1, which requires a lot of time and effort for the connection work, resulting in poor work efficiency and the possibility of dust getting stuck in the connection part. Because the guide pipe 4 was rotated without realizing that the lead pipe 4 was in the correct position, problems such as seizure of the connecting portion and the like, which made it difficult to connect, often occurred.

This invention was made for the purpose of improving the above-mentioned problems.

Means and action for solving the problem In a system in which a pilot pipe with a pilot head with a direction control function connected to the tip is propelled underground by a pipe burying machine installed on the starting bit side, both ends of each pilot pipe are A male joint and a female joint each having a plurality of engaging protrusions with an inclined surface protruding from one end in the circumferential direction are provided, and the leading pipe to be connected can be connected by only slightly rotating it. Conduit connection device.

Embodiment This invention will be described in detail with reference to an embodiment shown in FIGS. 1 to 3. In the figure, 10 is a leading pipe that is propelled underground by a pipe burying machine 2, and a male joint is attached to one end. 11, and the male joint 1 on the other end side.
1 is provided with a female joint 12 into which it can be freely fitted.

The male joint 11 has a small diameter portion 11a that is smaller in diameter than the outer diameter of the leading pipe 10.
Locking protrusions 11b are protruded from the outer circumferential surface at equal intervals in the circumferential direction. As shown in FIG. 1, the locking protrusion 11b has an elongated block shape in the axial direction, and one end is set back slightly from the tip of the small diameter portion 11a, and the end surface is parallel to the end surface of the small diameter portion 11a. It's becoming like that.

Further, the other end side of the locking protrusion 11b is an inclined surface 11c that slopes in the same direction as each of the locking protrusions 11b.

On the other hand, a female joint 12 with which the male joint 11 engages
A fitting part 12a into which the small diameter part 11a of the male joint 11 can be fitted is formed on the inner peripheral part of the other end of the leading pipe 10, and a part is formed on the inner peripheral surface of the fitting part 12a in the circumferential direction. Engagement protrusions 12b are provided protrudingly at equal intervals. These engaging protrusions 12b have the same size as the engaging protrusions 11b of the male joint 11, and each of the engaging protrusions 11
A gap 11d, 12d is provided between the engagement projections 12b, 12b through which the engagement projections 12b, 11b can pass. An inclined surface 12c is formed in surface contact with the surface 11c.

Next, to explain the operation, when propelling the leading pipe 10 underground, the pilot head 5 is connected to the tip 10 of the leading leading pipe as in the conventional case, and the pipe burying machine 2 installed in the starting bit 1 is used to propel the pilot pipe underground. Propel it inward (see Figure 1). After advancing the length of the leading pipe 10, the female joint 12 of the leading pipe 10, which is added to the male joint 11 provided at the rear end of the leading pipe 10, is inserted into the second
As shown in the figure, it is inserted in the direction of arrow A, and the leading tube 10 on the supplementary side is rotated in the direction of arrow B, as shown in FIG. As a result, the inclined surface 11c of the engaging protrusion 11a protrudingly provided on the male type joint 11 causes the inclined surface 12 of the engaging protrusion 12a protrudingly provided on the female type joint 12.
c contact each other, and the inclined surface 1 of the engagement protrusion 11a
1c advances the engagement protrusion 12a in the direction of arrow C, the end face of the replenishment-side leading pipe 10 is strongly pressed against the stepped portion 11e of the leading pipe 10 that has already been pushed into the ground, completing the connection of both leading pipes 10. do.

Thereafter, the above operation is repeated every time the leading pipe 10 is propelled one pitch, and the leading pipes 10 are successively added, so that each connection part does not loosen even if the leading pipe 10 is rotated in the direction of arrow B during propulsion. From this, it is also possible to correct the rolling of the pilot head 5 by rotating the guide pipe 10 on the side of the starting bit 1.

In the above embodiment, a case has been described in which the female joint 12 is connected to the male joint 11 of the preceding leading pipe 10, but of course the reverse may be used.

Effects of the invention As detailed above, this invention provides a male joint 11 and a female joint 12 at both ends of the leading pipe 10, and by simply slightly rotating the leading pipe 10 to be added,
Since the leading pipe 10 can be connected, there is no need to rotate the leading pipe 10 many times as in conventional threaded joints. With this, the leading pipe 10
Connection work can be done more efficiently in a shorter time, and reliability is also improved because there is less chance of dirt getting caught.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the state before connection of a leading pipe which is an embodiment of this invention, Figs. 2 and 3 are explanatory diagrams of the operation at the time of connection, and Figs. 4 to 6 are views of conventional pipes. It is an explanatory view showing a burying method. 1 is a starting bit, 2 is a pipe embedding machine, 10 is a leading pipe, 11 is a male type joint, 12 is a female type joint, 11a,
12a is an engaging protrusion, and 11c and 12c are inclined surfaces.

Claims (1)

[Scope of utility model registration request] A pilot pipe 10 with a pilot head 12 having a direction control function connected to the tip thereof is propelled underground by a pipe burying machine 2 installed on the starting bit 1 side. Slope 1
A leading pipe connecting device comprising a male joint 11 and a female joint 12 each having a plurality of engagement protrusions 11a and 12a projecting in the circumferential direction.