JPS61292514A - Bent hole measuring apparatus - Google Patents

Abstract

PURPOSE:To enable reduction of counting frequency of the apparatus and improvement of measuring accuracy, by arranging supporting points of the measuring tube in such a way that the supporting points can be distributed covering the longest distance. CONSTITUTION:A preliminary measurement is performed, by shortening an arm 22 of rotating rollers 20a, 20b, 20c on both ends and supporting a measuring tube 14 with supporting points in equal distance with the shortest distances, A1-A3. Next, from results of the preliminary measurement rough bend and radius of curvature of the excavating hole 24 are obtained and deviation of the axial direction of the hole 24 is examined and the longest distance L1+L2 of the supporting points relative to the deviation is determined. Next, the arm 22 is extended according to the distance L1+L2 between the supporting points and after changing the supporting points from A1 A1', and A3 A3' for the repeated measurement. Thus, as the distance between the supporting points has become longer as compared with that of the preliminary measurement, even if the bend of the same excavating hole 24 is measured, a drastic reduction of measurement frequency can be accomplished for decreasing the cumulative error and thus for improvement of the measuring accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hole curvature measuring device, and particularly to a device for measuring the degree of curvature of an excavated hole.

(Prior art) Normally, holes drilled with a boring machine etc. do not have perfect straightness and are curved in either direction, and horizontally drilled holes in particular are forced downward due to the gravity acting on the boring machine. It tends to be sloping.

By the way, for relatively small-diameter drilling holes such as advanced pilot holes in oil fields, wells, and tunnels, it is necessary to measure the curvature of the pilot hole because it is necessary to accurately determine the positional relationship with the main pile. Must be.

For this reason, conventionally, a measurement tube is used, which is made by connecting two cylinders containing a laser oscillator and a television camera with a flexible member, and this is inserted into the excavation hole, and the measurement tube is placed in front and behind the visibility member. A measuring device was used that used a laser beam and a television camera to detect the difference in inclination angle between the cylinders.

This type of measuring device takes measurements while sequentially moving inside the borehole, but the movement was done in an inchworm-like manner so that the optical axis of the previous measurement was used as the reference optical axis for the next measurement. .

(Problems to be Solved by the Invention) In the conventional measuring device described above, since the transfer is done in the shape of an inchworm, the length of the excavation hole to be measured is approximately 1/1/1 of the length of the measuring pipe.
Over a number of times divided by 2.

Therefore, there is a problem in that errors from each measurement are accumulated, resulting in a decrease in measurement accuracy.

In order to reduce the number of measurements, the total length of the 11 pipes can be reduced, but the degree of curvature of the borehole varies widely.
If it is made infinitely long, the inclination will be absorbed by the cylindrical part, making it impossible to accurately measure the hole surface.

This invention has been made in view of the above-mentioned problems, and its purpose is to provide a hole surface measuring device that can reduce the number of measurements and improve measurement accuracy. .

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a measurement tube which rotatably connects one end of a pair of cylindrical bodies to be inserted into an excavation hole, and A measuring device in which a light receiving displacement detecting device and a laser emitting device are each built in on the other end side, and the measuring tube is supported at three points at equal intervals, and a traveling device is disposed at each of the supporting points. It is characterized in that the distance between the support points is variable.

(Function) Since the distance between the support points of the measurement pipe is variable, for example, take a preliminary measurement at the shortest support point distance to understand the outline of the bend in the excavation hole, and then set the distance between the support points optimally. If the main measurement is performed after this, the number of measurements will be reduced and the bend can be measured with high precision.

(Example) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a hole surface measuring device according to the present invention.

The hole surface measurement position (vt), which is not shown in the same figure, is a ball joint 12 in which a through hole is formed centering on one end of a pair of hollow cylindrical bodies 10, 108, as shown in its entirety in FIG. C, C, and O provided near the tip of one cylindrical body 10 so as to be orthogonal to the same axis.
It has a target 16 and a laser beam emitting device 18 provided on the cylinder axis near the rear end of the other cylinder 10a, and the target 16 has C, C, and D elements arranged in a two-dimensional direction. It has a planar shape, and is adjusted so that when the measuring tube 14 is placed in a horizontal state, the laser beam projected from the emitting device 18 irradiates the origin.

Below the cylindrical body 10.10a, there is a lever 3. driven by an electric motor or the like. III (1) Rotating row-7-20a, 20b
, 20C are provided, and rollers 20a, 20 on both sides are provided.
b.

20c are respectively attached to arms 22.22 housed inside the cylindrical body 10.10a, and are extendable and retractable between the solid and imaginary lines in FIG.

The measurement tube 14 is inserted into an excavation hole 24 that is dug approximately horizontally, and a vibrator 26 is inserted into the excavation hole 24 in advance.

The vibrator 26 is flexible enough to deform along the curve of the excavated hole 24, and is suitably made of, for example, a vinyl chloride pipe or a relatively thin aluminum pipe.

Furthermore, a narrow rail 28 is installed inside the pipe 26 and extends along the axial direction of the pipe 26.
7-20a, 20b, 20c 1. t, is placed on the col rail 28, and is supported at three points where the rollers 20a, 20b, 20c and the rail 28 contact.

The principle of the measuring device is that a bend in the drilled hole 24 appears on the vibrator 26 and the rail 28, and the relationship between the laser beam of the emitting device 18 and the target 16, whose origin has been adjusted in advance, deviates at the bend. The radius of curvature of the borehole 24 can be calculated by repeating measurements in an inchworm-like manner along the axial direction of the borehole 24 and finding each offset position.

In the measuring device of the present invention, first, as shown by solid lines in FIG. 1, the rotating rollers 20a and 20b at both ends.

The arm 22 of 20c is shortened and the measurement tube 14 is supported at short support points (A5, A2, A3) from R at equal intervals L+,
Perform preliminary measurements.

When the approximate curve and radius of curvature of the excavated hole 24 are determined as a result of preliminary measurements, the axial deviation of the hole 24 is examined, and the longest distance between supporting points Ll +12 is determined according to the deviation.

When the distance Ll +12 between support points is determined, the arm 22 is extended correspondingly, and the support points on both sides are changed from Δ1→A+',
Change from A3 to A3' and measure again.

In the main measurement, the distance between the support points is larger than in the preliminary measurement, so even if the bend in the same borehole 24 is measured, the number of measurements is significantly reduced, the cumulative error is reduced, and therefore Measurement accuracy is improved.

Note that the measuring tube 14 can be moved by pushing the entire measuring tube from the rear, but it is also possible to move the measuring tube 14 by pushing the entire measuring tube from the rear.
It is desirable to drive c with a stepping motor, for example, and move it by a constant length.

(Effects of the Invention) As described above in detail in the embodiments, according to the hole surface measuring device according to the present invention, the support point of the measuring tube can be set to the longest length depending on the degree of curvature of the hole. This has the effect of reducing the number of measurements and greatly improving measurement accuracy.
It will be done.

[Brief explanation of the drawing]

FIG. 1 is an overall explanatory diagram showing one embodiment of the device of the present invention, and FIG.
The figure is a sectional view of FIG. 1. 10.108・・・Cylinder

Claims (1)

[Claims] A measurement tube rotatably connected to one end of a pair of cylinders to be inserted into the borehole, and a light receiving displacement detecting device and a laser emitting device respectively built in the other end of the cylinders,
A hole bending measuring device in which the measuring tube is supported at three points at equal intervals, wherein a traveling device is provided at each of the supporting points, and the distance between the supporting points is variable. .