JPS6253054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a height measuring device that measures height using an electrical method.

Conventionally known height meters are composed of a column with a scale and an overhead board that can be moved along the column. The scale is measured by touching the top of the head.

Since such conventionally known height meters measure the scale, they suffer from measurement errors and have the disadvantage that highly accurate height measurements cannot be performed.

The present invention seeks to realize a height measuring instrument that does not have these drawbacks.

Fig. 1 is an outline drawing showing one embodiment of the present invention, Fig. 2 is an outline drawing showing an embodiment of the present invention;
The figure is a perspective view of the main part, and FIG. 3 is an electrical block diagram. In these figures, 1 is the base, 2
is a column, 3 is an overhead board that moves along the column, 4 is a magnetostrictive wire stretched parallel to the column 2, and its ends 41,
42 is lightly supported so that mechanical vibrations are not transmitted, and is configured so that the ultrasonic signal generated within the magnetostrictive wire is reflected. Reference numeral 5 denotes an excitation and reception means that moves together with the overhead plate 3 and couples to the magnetostrictive wire 4, which generates an ultrasonic signal within the magnetostrictive wire 4 and also receives the ultrasonic signal reflected at both ends 41 and 42 of the magnetostrictive wire. Receive. Note that although an example is shown here in which excitation and reception are performed by one coil, these may be performed separately.

OS is an excitation pulse generator operated by a push button PB, and its output pulse is applied to the excitation receiving means 5 via a diode DO. FF
Both 1 and FF2 are flip-flop circuits,
Output pulses from the excitation pulse generators OS are respectively applied to the set terminals S via comparators. Further, the received signal from the excitation receiving means 5 is applied to the reset terminal R via comparators OP ₁ and OP ₂ and preset counters PC ₁ and PC ₂ , respectively. CK is flip-flop circuit FF1,
an arithmetic circuit to which the time width signal from FF2 is applied;
IN is an indicator that displays the calculation results of the calculation circuit CK in analog or digital form. Each flip-flop circuit FF1, FF2, arithmetic circuit CK, and indicator IN are all mounted on the overhead board 3.

The operation of the apparatus configured in this way will be described next.

The person to be measured MH is made to stand upright on the base 1, and the overhead board 3 is brought into contact with the top of the head of the person to be measured. This operation is similar to the measuring method of a conventionally known height meter. In this state, the push button switch PB is used to operate the excitation pulse generator OS, which outputs excitation pulses at regular intervals. When an excitation pulse is applied to the excitation receiving means 5, a so-called Joule
Due to the effect, the position of the excitation means 5 and the magnetostrictive wire 4
Ultrasonic signals are generated inside the In such an operation of generating an ultrasonic signal, the excitation receiving means 5 receives the magnetostrictive wire 4.
It is performed under the same conditions no matter where it is placed in the throat. The pulses from the excitation pulse generator OS generate ultrasonic signals within the magnetostrictive line 4 at the position of the excitation receiving means 5 via an excitation receiving means 5 movable along the magnetostrictive line 4, and Each flip-flop circuit FF1, FF2 is set to a set state via a comparator.

The ultrasonic signal generated within the magnetostrictive wire 4 at the position of the excitation receiving means 5 propagates toward both ends of the magnetostrictive wire 4 as a propagation path, and reaches both ends 41 and 42.
, propagates again through the magnetostrictive line 4 and is detected by the excitation receiving means 5 . In this embodiment, a coil is used as the excitation receiving means, so when an ultrasonic signal passes through the magnetostrictive wire 4 close to this coil, a pulse-like voltage e ₁ , e ₂ occurs. Comparator OP ₁ ,
OP ₂ distinguishes between the excitation pulse from the excitation pulse generator OS and the received pulse from the excitation receiving means 5 (the excitation pulse and the received pulse are different in polarity and amplitude), selects only the received pulse, Further, preset counters PC ₁ and PC ₂ select the first and second received pulses, respectively. Therefore, for example, the first received pulse is applied to the reset terminal R of the flip-flop circuit FF1, and the second received pulse is applied to the reset terminal R of the flip-flop circuit FF2. Assuming that an ultrasonic signal is generated at the position of the excitation receiving means 5 at the same time as the excitation pulse is applied, this ultrasonic signal propagates through the magnetostrictive line 4 and is reflected at both ends 41 and 42 of the ultrasonic signal.
The propagation times t ₁ and t ₂ for excitation and reciprocation to the position of the receiving means 5 can be expressed by equations (1) and (2).

t ₁ = 2x/v _s (1) t ₂ = 2(L-x)/v _s (2) where, v _s : Speed at which the ultrasonic signal propagates within the magnetostrictive wire 4 x : Measured height (excitation reception (distance between the means 5 and the reflective end 41) L: length of the magnetostrictive line 4; here L-x is chosen so that it is always larger than x;

Each of the flip-flop circuits FF1 and FF2 is set by an excitation pulse and reset by a received pulse, and from this point on, the flip-flop circuits have a time width corresponding to the round-trip propagation times t ₁ and t ₂ described above. Pulse width signals are obtained and these signals are applied to the arithmetic circuit CK. The arithmetic circuit CK inputs these two time width signals t ₁ and t ₂ and calculates the height x by calculating, for example, equation (3).

t ₁ −t ₂ /t ₁ +t ₂ =2x−L/L x=L/2(t ₁ −t ₂ /t ₁ +t ₂ +1) (3) The advantage of performing such calculation is that The height x can be measured without being affected by the signal propagation velocity v _s (this propagation velocity v _s changes due to changes in ambient temperature, etc.). Then, the indicator IN indicates the result of this calculation. Since this display is made on the overhead board 3, touching the overhead board 3 to the top of the head, giving measurement instructions, and reading the indicated value can be easily performed as in the conventional case.

In the above embodiment, the excitation means and the reception means are shared, and are made of a coil wound around the magnetostrictive wire, but other structures may be used, and permanent magnets may be placed near these means. The magnetostrictive wires may be arranged so as to bias the magnetostrictive wires and increase the excitation or reception efficiency. Moreover, although the case of measuring height has been described here as an example, it is of course applicable to measuring sitting height and other lengths.

As described above, according to the present invention, it is easy to digitally display measured values, there is no measurement error, and there is no influence of ambient temperature, etc., so it is possible to realize a height measuring device with high measurement accuracy.

[Brief explanation of the drawing]

Fig. 1 is an outline drawing showing one embodiment of the present invention, Fig. 2 is an outline drawing showing an embodiment of the present invention;
The figure is a perspective view of the main part, and FIG. 3 is its electrical block diagram. 1... Base, 2... Support, 3... Overhead board, 4...
...Magnetostrictive wire, 5...Excitation receiving means, FF1, FF2...
...Flip-flop circuit, CK... Arithmetic circuit, OS
...Pulse generator, IN...Indicator.

Claims (1)

[Scope of Claims] 1. A height measuring device consisting of a support and an overhead plate movable along the support, which is extended approximately parallel to the support and configured to reflect ultrasonic signals at both ends thereof. a magnetostrictive wire, and an excitation and receiving means that moves with the head plate and couples to the magnetostrictive wire to generate an ultrasonic signal within the magnetostrictive wire and receives the ultrasonic signal reflected at both ends of the magnetostrictive wire; circuit means for obtaining round-trip propagation times t ₁ and t ₂ for the ultrasonic signal generated in the magnetostrictive wire by the excitation means to reflect at both ends of the magnetostrictive wire and reach the receiving means; and the round-trip propagation. Input signals related to times t ₁ , t ₂ , at least t ₁ −t ₂ /t ₁ +t
An arithmetic circuit for performing arithmetic operations including _{the second} arithmetic operation to determine the height, and an indicator for displaying the arithmetic results of the arithmetic circuit are provided, and the circuit means, the arithmetic circuit, and the indicator are mounted on the overhead board. A height measuring device characterized by: