JPH0547761B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic distance measuring device that measures the distance between two points or the amount of change thereof.

When constructing a tunnel, the ground inside the tunnel is extremely unstable immediately after excavation, and its cross-sectional diameter decreases over time.

Therefore, in order to cast inner concrete,
This was carried out at a time when the changes in the ground had subsided to some extent.

In order to determine the timing, it is necessary to measure the cross-sectional dimensions of the tunnel or the amount of change thereof over time, and conventionally, measurements have been carried out using the following methods.

In other words, a steel tape with a scale is used, a constant tension is applied to the tape, the scale of the tape is measured at two measurement points set on the ground where the amount of change is to be measured, and temperature correction is performed. and calculate the measured value.

The above operations were repeated at regular intervals, and the data was aggregated each time to determine the amount of change.

However, such conventional measurement methods have the following problems.

<A> The reliability of the measured values was low because measurements could not be made with a constant tension applied to the steel tape.

<B> Highly accurate measurements were not possible because the steel tape did not have a vernier device that could read it with a high resolution of mm or less.

In particular, in order to understand the timing of pouring inner concrete in a tunnel, the accuracy of measuring the amount of change in the ground is 1/10 mm.
A very high degree of accuracy is required.

<C> It takes a lot of effort and time to actually determine the amount of change, such as reading the scale on the steel tape, writing in the field notebook, subsequent temperature correction, and data processing.

<d> The above-mentioned problems are similar to those in other accurate distance measurements such as reference line measurement in triangulation.

The present invention was made to solve these conventional problems, and it is an object of the present invention to provide a distance automatic device that does not require time and effort for measurement and has high measurement accuracy.

Next, an example will be described.

<A> Overall configuration One end of the moving frame 3 is connected and positioned with a load cell 43 inside the outer box 8.

The movable frame 3 is supported by rollers 81 protruding within the outer box 8 so as to be movable in the direction of expansion and contraction of the load cell 43.

The free end of the steel tape 4 wound around the moving frame 3 is exposed to the outside of the outer box 8 from a position symmetrical to the load cell 43.

<A> Tape winding section As shown in Fig. 1, a tape reel 41 is built into the movable frame 3, and a steel tape 4 wound in a roll is wound around this tape reel 41. One end is pulled out to the outside of the outer box 8.

The outer surface of the outer box 8 on the side where the load cell 43 is attached is provided with a fixture 42a for attaching the device to the measurement ground.

The steel tape 4 is a narrow tape made of a known material, and the tape surface has precise regular intervals, for example, 5
Slits 44 are opened at equal intervals of cm to 10 cm.

One end of an L-shaped handle 5 is integrally connected to the center of the tape reel 41, and a foldable grip 51 is connected to the other end of the handle 5. tape 4
The structure is such that it is possible to wind up the material.

The grip 51 is configured to allow folding only in the direction of rotation of the handle 5 at its midpoint position;
The end of the grip 51 is threaded.

Furthermore, a ratchet gear 31 having a gear formed inside a ring around the handle 5 is fixed to the side surface of the moving frame 3 on the side where the grip 51 is attached.

Furthermore, a large number of insertion holes 32 (eight locations in the drawing) are provided inside the ratchet gear 31 at equally divided points on the circumference.

Further, in order to fix the ratchet gear 31 and finely adjust the rotation of the handle 5, a stopper 6 having a pawl 61 as shown in FIG. 2 is used.

The stopper 6 has a reaction arm 6 on one side of the short axis 63 passing through the claw 61 and extending in a direction intersecting the short axis 63.
2 is attached, and a notch 64 is made in the plate surface of the reaction arm 62.

To briefly explain how to use the stopper 6, insert the short shaft 63 into the hole 3 at the position where the notch 64 of the stopper 6 is closest to the vertically folded grip 51.
2, pull out the pipe fitted in the grip 51, insert it into the notch 64, and fix it with an adjustment nut 65.

As a result, the pawl 61 engages with the ratchet gear 31 to restrict rotation of the stopper 6 and handle 5.

If it is simply to restrict the rotation of the handle 5 in the opposite direction, there is no need to arrange the stopper 6, etc., and it is sufficient to adopt only the ratchet structure, but the reason for using the stopper 6 is as described below. This is because by tightening the adjustment nut 65, the tension force applied to the steel tape 4 can be finely adjusted without being affected by the one-pitch gear of the ratchet gear 31.

<B> Tape Counter Two pairs of light-receiving elements 11 and light-emitting elements 12 are disposed facing each other in the middle of the moving frame 3 of the steel tape 4 pulled out from the tape reel 41.

When the steel tape 4 moves between the light receiving element 11 and the light emitting element 12 in either direction, the light receiving element 11
The structure is such that the light emitted from the light passes through the slit 44 and is received by the light emitting element 12, and the number of times this light is sensed can be stored.

That is, by storing the number of passes of the slit 44 that passed between the light receiving element 11 and the light emitting element 12, the amount of movement of the steel tape 4 is obtained by multiplying the number of passes by the interval between the slits 44.

The reason why two pairs of the light receiving element 11 and the light emitting element 12 are provided is that the moving direction of the steel tape 4 (normal rotation or This is to confirm the reversal.

Further, a thermometer 7 is installed in the outer box 8 for the purpose of collecting data for temperature correction.

<C> Vernier device If only the tape counter 1 described above is used, the minimum unit of movement of the steel tape 4 is large, and it is not possible to accurately measure it down to the millimeter level.

Therefore, as shown in FIG. 5, an encoder 21 of a known structure is used in the middle of the steel tape 4 pulled out from the tape reel 41 into the moving frame 3, and the roller 22 of the encoder 21 is placed in contact with the steel tape 4. do.

In addition to lining the circumferential surface of the steel tape 4 with hard rubber to prevent it from slipping on the roller 22, a pinch roller 23 also lined with hard rubber is arranged on the back side of the steel tape 4.

Note that the elasticity of a spring may be used to obtain high adhesion between the rollers 22 and 23.

By employing the encoder 21 in this way, the resolution can be increased to, for example, the encoder 21 divided into 2000 parts.
When using slits 44, if the interval between the slits 44 is 5 cm, the minimum unit is 50/2000=1/40, that is, it is possible to measure up to 0.025 mm.

<d> Computer section A microcomputer 9 is built into the movable frame 3.

As the microcomputer 9, a known one is used which can comprehensively process data by receiving, recording and storing measured values, analyzing and plotting, etc.

Specifically, the load cell 43, the encoder 21,
Contact each part of tape counter 1 and thermometer 7,
The system is configured to collect necessary data from each of these parts and process it automatically.

Next, a measurement method for measuring the amount of change in the ground inside a tunnel will be explained.

<B> Installation of the device After confirming the operating status of each part of the device of the above structure, determine two measurement points at opposing positions on the ground in the tunnel to be measured, and install both fixtures 42a, 42b respectively.

When drawing out the steel tape 4, the steel tape 4 is first set to zero with the steel tape 4 completely wound around the tape reel 41, and then the steel tape 4 is drawn out while reading and memorizing the slit 44 with the tape counter 1.

<B> Winding up the steel tape After connecting both fixtures 42a and 42b to the measurement point, continue applying tension to the slightly slack steel tape 4 by rotating the handle 5.

When winding the steel tape 4, the tension applied to the steel tape 4 is usually around 8Kg to 10Kg, so if you simply turn the winding handle of a general steel tape, the steel tape 4
It is difficult to measure by one person because it shakes and requires a large amount of human power to rotate, and it is also difficult to measure with high precision.

Therefore, when winding the steel tape 4 as in the device of the present invention, after winding it with the handle 5 to an extent that does not reach a predetermined tension, the grip 51 connected to the handle 5 is connected to the ratchet gear 31 as described above. Fold it down in parallel, and also insert the short shaft 63 of the stopper 6 into the insertion hole 32 at a predetermined position to fix the reaction arm 62 and cut out the notch 64.
Screw the grip 51 on and tighten the adjustment nut 65.
By tightening, rotational force can be applied to the handle 5 without applying any force to the moving frame 3.

<C> Measurement The microcomputer 9 is set in advance so that measurement is performed when a certain tension is applied to the load cell 43, so when the handle 5 is continued to be wound, a predetermined tension is applied to the load cell 43 between predetermined measurement points. When this occurs, the microcomputer 9 instantaneously issues a reading stop signal to the tape counter 1 and encoder 21.

Upon receiving this signal, the tape counter 1 and encoder 21 immediately stop reading, and the immediately preceding value becomes the measured value.

Repeat the above work after half a day or several days and measure the amount of change in the ground.

Since the present invention is as explained above, the following effects can be expected.

<B> Because the encoder is combined with a tape counter, for example, when using a 2000-division encoder, the reading resolution ability can read down to 1/40 mm (0.025 mm), and errors due to slippage of the steel tape and elastic deformation of the roller and pinch roller can be avoided. Even if such factors are subtracted, the measurement accuracy can be trusted to within 1/20mm (0.05mm).

<B> By adopting a foldable handle and an independent stopper, tension can be easily applied to the steel tape quietly and with little effort without adding vibration to the tape.

<C> By automating tension management and using a digital display with no reading errors, the measurer does not need to be an expert like in the past, and can perform measurement analysis and plotting by himself.

<D> Automatic reading and memorization are possible, so if a wireless transmitter is installed in this device, it can be input into a computer located in an office or other location far from the site for analysis and drawing, and the next construction decision can be made on the spot. I can do it.

<E> By automating temperature correction, correction values can be obtained on the spot, so there is no need to perform correction after measurement is completed, resulting in labor savings.

<F> Conventional device (Utility Model Application Publication No. 186806/1983)
Some types of tape include a clamp mechanism that grips one end of a perforated tape with a scale, a tension mechanism that slides this clamp mechanism, and a dial gauge that is integrated with the tension mechanism.

With this device, the scales on the tape and dial gauge are read visually by the worker, which can lead to errors in measurement values, resulting in a decrease in accuracy.

Further, when using this device for measurement, there are many manual steps, which is complicated and leads to a decrease in accuracy.

However, the present invention requires almost no manual work, does not require visual measurements, and can automatically perform measurements quickly and easily.

[Brief explanation of the drawing]

Fig. 1: An explanatory diagram of an embodiment of the device according to the present invention, Figs. 2 and 3: An explanatory diagram of a tape winding section, Fig. 4
Figure: Cross-sectional diagram of tape counter, Figure 5: Diagram of vernier device 1: Tape counter, 2: Vernier device, 3: Moving frame, 4: Steel tape, 21: Encoder, 4
4: Slits.

Claims (1)

[Scope of Claims] 1. An outer box having a fixture that can be attached to one measurement point, a moving frame movably housed in the outer box, and an outer box and a moving frame capable of expanding and contracting in the moving direction of the moving frame. A load cell connected between the two, a tape reel installed in the moving frame, a tape with holes at regular intervals that can be wound up by the tape reel and one end of which can be pulled out to the outside of the outer box, and an outer box. A mounting device that can be attached to the other measurement point is attached to the end of the tape pulled out to the outside, and a light-receiving element and a light-emitting element are placed in the moving frame with the pulled-out tape in between, and the holes in the tape are used to detect and emit light. There is a tape counter that stores the number of times the tape has passed between elements, an encoder that holds the pulled out tape between a pair of rollers installed in a moving frame and measures the distance the tape moves from the amount of rotation of the rollers, and a tape reel. The tension of the tape pulled out by the load cell is measured in response to a reaction force for winding the tape, and when the tension of the load cell reaches a certain value, a reading stop signal is sent to the tape counter and encoder, and the tape counter and An automatic distance measuring device that consists of a computer section that processes data from the encoder and automatically calculates the tape pull-out distance immediately before reading stops.