JPH0229122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field to Which the Invention Pertains) The present invention relates to a device for detecting co-lifting of drain material when pulling up a mandrel.

(Problems to be solved by the invention and its features) In the drain construction method, a drain material such as drain paper is inserted into a mandrel and penetrates into the ground, and then only the mandrel is pulled up to the ground while leaving the drain material in the ground. The drain material is installed underground, but sometimes the drain material rises together with the mandrel.

To detect this co-rising, it is sufficient to detect the state of movement of the drain material relative to the mandrel during the process of pulling up the mandrel.One way to do this is to attach objects to be detected, such as metal pieces, to the drain material at predetermined intervals. The present applicant has already proposed that the object to be detected be detected by means of a detection means installed at an appropriate position on a mandrel (Japanese Patent Application No. 77257/1983), but this prior art does not allow detection of objects to be detected in large quantities. However, there is a problem in that it is economically disadvantageous to use it once and make it disposable.

An object of the present invention is to provide a new device that can reliably detect the co-rising phenomenon of drain material without making the object to be detected disposable or without using the object to be detected at all. , its structural features are as described in the claims.

Detection of co-lifting of drain material by each device of the present invention is performed by examining the detection signal sent from the detection means to the observation device or recording device on the ground and detecting the state of movement of the drain material relative to the mandrel. It is something.

In each device of the present invention, the protrusion provided on the circumferential surface of the roller is for ensuring engagement between the roller and the drain material, that is, the protrusion provided on the circumferential surface of the roller is provided to ensure engagement between the roller and the drain material, that is, the protrusion is provided in a relatively downward direction while in contact with the roller and its circumferential surface. This is to prevent slippage between the moving drain material and to rotate the roller in accordance with the movement of the drain material.
It is preferable to provide an auxiliary roller on the front surface of the roller provided with the protrusion, which cooperates with the roller to sandwich the drain material.

As in the prior art, the object to be detected in the first invention uses a magnet, a reflector, etc. in addition to an ordinary metal piece. The number is usually plural, but it may be one, and in the case of plural, it is preferable to provide them at equal intervals in the circumferential direction of the roller.

A potentiometer or a synchronizer is used as the detection means of the second invention, and the second invention detects the rotation angle of the roller.

(Explanation based on the drawing) The drawing shows the lower end of the mandrel for installing the drain paper, and the drain paper 1 is
As shown in the figure, after the mandrel 2 is inserted into the ground, only the mandrel 2 is pulled up to the ground and installed at a predetermined position underground.

In FIGS. 1 and 2 showing an embodiment of the first invention, 3 is a non-metallic roller attached to the inner wall of the lower end of the mandrel 2 via a horizontal shaft 4;
Detected objects 5 such as a plurality of metal pieces are attached to the circumferential surface of the sensor by means of adhesive or the like.

An auxiliary roller 6 is provided in front of the roller 3 with a slight gap, and one side of the drain paper 1 sandwiched between the roller 3 and the auxiliary roller 6 is always in contact with the roller 3. When the paper moves downward relative to the mandrel 2, the roller 3 rotates in response to this movement, and the drain paper 1 and roller 3 at this time rotate.
A large number of protrusions 7 are provided on the circumferential surface of the roller 3 to ensure engagement with the roller 3.

In this embodiment, the roller 3 has a sensing object 5 and a protrusion 7.
However, it is also possible to provide only the protrusion 7 on the roller 3 and provide the detected object 5 on another roller attached to the horizontal shaft 4.

8 is a detection means attached to the mandrel 2 in a posture perpendicular to the circumferential surface of the roller (roller 3 in the illustrated embodiment) to which the detected object 5 is attached;
This detection means 8 is designed to emit a detection signal (pulse) every time the object to be detected 5 passes in front of it. Therefore, the interval between the detection signals indicates the state of movement of the drain paper 1 with respect to the mandrel 2, and by examining this, it is possible to know whether or not the drain paper 1 is rising together.

In FIGS. 3 and 4 showing an embodiment of the second invention, 3' is a roller that contacts one side of the drain paper 1, 4' is the rotating shaft of the roller 3', and 7' is the periphery of the roller 3'. A projection 9 provided on the surface is a detection means provided at one end of the rotating shaft 4'.

The detection means 9 is a potentiometer or a synchronizer, and in this case, the state of movement of the drain paper 1 with respect to the mandrel 2 is detected by the rotation angle of the rotation shaft 4'. There is no need for a detected object like this.

Although not directly related to the present invention, reference numeral 10 in FIGS. 1 and 3 indicates the lower end of the mandrel 2 in order to prevent ground soil from entering the mandrel 2 when the mandrel 2 penetrates into the ground. 11 is an arch-shaped recess provided in the opening, and 11 is a recess 10 in order to suppress the drain paper 1 from rising together.
It is a rotating piece provided on the outside of the

(Effects of the Invention) Since the present invention is as described above, the state of movement of the drain material relative to the mandrel can be reliably converted into the rotation of the roller and detected, and in the first invention, Although this involves the use of a detection object, unlike the prior art, a large amount of detection objects are not thrown away, and in the first invention, no detection object is used at all, so it is extremely economical. It is possible to detect co-rising of drain material.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the first invention;
Figure 2 is a sectional view taken along the line X-X in Figure 1, and Figure 3 is a cross-sectional view of Figure 2.
FIG. 4 is a longitudinal cross-sectional view showing one embodiment of the invention, and FIG. 4 is a cross-sectional view taken along the line Y--Y in FIG. 3. In the figure, 1: drain paper, 2: mandrel, 3, 3': rollers, 5: object to be detected, 6: auxiliary roller, 7: protrusion, 8, 9: detection means, etc.

Claims (1)

[Claims] 1. A roller having a protrusion on the circumferential surface to ensure engagement with the drain material is attached to the lower inside of the mandrel, and the circumferential surface of the roller or another roller interlocking with the roller is attached. Detection of co-raised drain material, characterized in that an object to be detected such as a metal piece is attached to the surface of the mandrel, and means for detecting the object to be detected is provided at a location of the mandrel facing the roller to which the object to be detected is attached. Device. 2. A roller having protrusions on the circumferential surface to ensure engagement with the drain material is attached to the lower inside of the mandrel, and a detection means for detecting the rotation angle of the roller is provided on the rotation axis of the roller. A system for detecting the rising of drain material.