JPS5931417A - Liquid level switch - Google Patents

Abstract

PURPOSE:To display stable performance which hardly causes an error in measurement, by detecting the oscillation frequency variation of an oscillator consisting of one side of a voltage vibrator and an amplifier by the resonance characteristic of the other side of the voltage vibrator. CONSTITUTION:A liquid level switch has the 1st piezoelectric vibrator 10 and the 2nd piezoelectric vibrator 12 which have mutually uniform characteristics, and the vibrating surface 14 of the 1st piezoelectric vibrator 10 is positioned where detection is performed; the oscillator 18 consists of the 1st piezoelectric vibrator 10 and the 1st amplifier 16, the oscillation output of the oscillator 18 is supplied to the 2nd vibrator 12, and the resonance output of the 2nd vibrator 12 is regarded as a detection output. Then, the oscillation frequency variation of the oscillator 18 is detected by the resonance characteristic of the 2nd piezoelectric vibrator 12 to display the stable performance which hardly causes an error in measurement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid level switch (1), which converts liquid level information +li in a special number J container into an electrical signal. -Related 1゜What is the conventional means for sending out the liquid level 18 report of this second to the outside? i-type tALLl wave j(.

)I':I -l-Such formula q of uni-unimany 1
11 stages are provided.

But if. These 6 formulas were 6th order, 11° and 9 right.

! I), the capacitance type is very narrow bz-s!
Using a pair of small poles forming a t-tube, we determine whether this voltage (the capacitance between the vessels (d) is J in the medium, and (detects a change J t), If foreign matter or moisture is (-1'l'l'IJ), then the measured difference is /
However, the ultrasonic method uses an optical Ikj device and a receiver δ device, and takes advantage of the fact that the propagation time of the ultrasonic wave is different depending on the medium v' (C). Measurement target 1 Gino 2-1
Measured 11 by degree or presence of lewdness? j difference is 41
It was also significantly affected by the sound of foreign rice ♀ II, such as when directly or when the object to be measured was input.

So-C) [1-to switch set is) self-1. floating,
When the first place number changed, J: turned the mechanical contact directly 1g drive 1 nozuru b
So (, 1 - there is no mentioned drawback - t), the crosspiece (1
One disadvantage is that it has a large size, which limits the installation position of the device.

Eliminating these problems with conventional liquid level detection means, IJ'/
The Buno method takes advantage of the fact that the resonant frequency of a barium material such as halium tannate/-X changes depending on the surrounding medium! I! M'c5 h'X, 1 stage to detect the change in resonance layer f skin number in air and liquid, JAQE frequency frequency optical first class circuit 42Driru l for comparison, ：Meni electrical configuration／）＜ ? J! &If, I”) h
jl M output object 1" ill! I constant JW 1m (7
):W1α change (Jl・]() is the compound weight!+-,
I'll add 61 points to the ft1 circuit and adjust the %.) If necessary, I'll address the problems. (I L:.

This defense was made in view of the above problems, and the purpose of this explanation is that it is not possible to achieve the objective in 1j, but the liquid level is very high, and a3 is high. The configuration of the target object is ``(31 Object to be detected 11 Iill'
l';i''ring 1 no'i q) i Todoro a /α change, foreign name field (for one disturbance of +7 - (1lllll 'j'Q
It was easy to avoid errors, but I inserted the fifi into the object to be detected and the installation location. The surface level switch is located at (-6).

Achieving this goal 1-1: I, this invention is waiting for the same ↑
] 1 to Vi 7J, two electric currents are connected to one vibration amplifier, and the other piezoelectric oscillation M ) If this other If'fIi oscillator's co-pregnancy special ↑
1 is characterized by J, t-(detected J, sea urchin).

(7) For example,
Please refer to Attachment 1 A.1 Drawing (!) for explanation.

FIG. 1 shows a liquid level novel switch according to the present invention.
This is an example. In this example, for jJ3, the oil level L/
/\/l/ Sui i7 f t, L #2 I1.1
: 141'l 17) IIyl-) 7. , : &
11 (1) Move the piezoelectric vibrator 12 of I-1'゛City Shinpaku 10) 2, position the vibrating surface 14 of the 1st monthly electric power (Pak 10) at the detection point, and The first piezoelectric vibrator 1o and the first amplifier 16 constitute an oscillator 18, and the oscillation output of this oscillator 18 is given to the second piezoelectric vibrator 12, and the resonance output of the second piezoelectric vibrator 12 is State (3rd
V) shown in the lower column of the figure is the detection nozzle J and the -(゛).

The first piezoelectric vibrator 1o has a piezoelectric body 2o made of barium ditanate or the like having a predetermined shape, and a metal elastic thin plate 22.
11. h'+ is achieved by pasting m with adhesive or the like.

Preferably, this first piezoelectric body 20 is properly housed inside a case 24 which has a hollow shape and has a hollow interior, and this case is placed against the wall surface of the liquid container 26 of the tank. Penetration), shape (79, 0 ring difficulty j
11 Patch 1゛2 Insert o and 971-304 table Y
While preventing the leakage of the JIJ liquid 32 (+1-L), the vibration surface 1-'I is used as the object to be detected:+2
+: Contact ability i7'f I! There is Shime-C.

1) Shake the bar 18. It, l! A small number of electrodes 32 formed by a method such as steaming on the Gekiden 1420 and the Bulletin Usune 22 constituting the first piezoelectric vibrator 10 and the first amplifier 16. Connect with 3/l wire (
1 has been achieved.

Then, the oscillation output tJ of this oscillator 18 is sent to the second piezoelectric sensor 12 as fl! There is a list of things that can be said about jis, this second one
1 [As the electric vibrator 12 (well, the above first n: the electric vibrator 10 has the same resonant frequency characteristics, h
Is it most desirable that it is made of l-material, j [lj
-'4Si l'l If it is right, other vibrations f
C(J, A(If the purpose of the invention is accomplished (;1 possible f+h.

In history, this implementation 1'y'l (Jd; 1st Chapter 2nd It 71 JAQ disturbance (12(: +5: issued!,,
:The output lij village is manually powered by the negative]2 amplifier each 36,
The output of the sea urchin (1-1) is manually inputted to the level switch 1 circuit 38 and sent to the outside from the level switch 1 circuit 38. Shii's love tUt-outside? ill IZ m
It is the four masterpieces of the above first month Z turtle ° shaking v J Ryo 10 /1~, -1 bullet 111 tb IN 22 is air (Well, as shown in Figure 12a, the piezoelectric body 20
The Jξ vibrational frequency determined by the external shape, thickness, etc. is 0 vibration.

When the elastic iW plate 22 is in a liquid, the mechanical impedance is different due to the difference in viscosity between the oil body and air, as shown in FIG.
The vibration is captured at the same frequency rl.

Such a change in the Jl-silver layer wave number of the first piezoelectric vibrator 10 corresponds to a change in the frequency of the oscillator 1ε30 light 1h'v, as shown in the middle column of FIG. 3, and the state of this change. is applied to the second piezoelectric vibration 1''12.

This second) f-electric vibrator 12 is shown in the lower column of FIG.
, ``The resonant frequency characteristics are determined by b, and the resonant frequency characteristics are determined by -)'
-('l' Rt shaker 'I B h day's I
F, if the JAG frequency is [0, i.e., the first pressure transducer 10 is in the air, then the best t) is the IJ in the matching state, the monthly electric station r゛12 no JcL
ri' (J) Figure 1/column J-Uii＾Electric 1u (Vl)
Then, the frequency from the optical amplifier '18 is [
1, that is, the first r + electric vibration '4 j'r
1 (v2) Do f ru 1゜This J, I: iiL: Nail (The monthly electric vibration of 1 is the resonance frequency change lj between the detected saliva and the air.
, the second iF: ``J to the fli oscillator 72''
It is converted into a change of ri j+'t. The potential change on the lever is amplified at a constant level by the amplifier 36 of the control circuit 2, and is input to the level switch circuit 3B.

This one-novel switch circuit 38 is constituted by an inverter, etc., and inverts the human input signal from the amplifier 36.
1(IJ(,='; j-shi is output from i2+b, and when the '1st piezoelectric first impulse f10 is in the air, the output is I1(impedance "[") sending out,
When the first monthly power activation end 10 is in dH, the output is -C high impedance "11'°."
Y, -) (For example, 1 novel switch f circuit 38 continues 18 series on the exit horn side. C only sounds the series δu1 The liquid level control in the liquid batter 26 is 1.
It becomes Noh.

Note that the detection of the liquid level of 48 f is performed based on the change in the resonant frequency when the electric withdrawal ends in contact with the body and body, so the object to be detected is limited to water, etc. Because it will be done (7)
For example, it can be applied to gasoline, etc., which may catch fire.

As a matter of fact, the liquid double level switch of this invention uses a piezoelectric vibrator to detect the liquid level condition. If you realize your gender
By converting changes in the liquid level state using an electric motor into changes in the electric motor, a special signal valve 11 circuit unlike the conventional one is no longer required, and liquid level information can be converted with a relatively simple configuration. Not only that, but also the piezoelectric vibrator for liquid level detection and the electric vibration for conversion? h-body iAA I'1. 'l 1]
1. Easily match! Therefore, special measures are required for 1Aa changes in the detected object and measurement environment.
−F stage ili': Digit i: < , 81Hj:
The stable motion r1 without the error 2j- becomes the i+J function. .

The moon-electrical vibration that detects the liquid surface state fji<1.1,
j; i t) + C O V] 5" shimono tongue (-
J I 1 is defense 11, D 1, J (' ＜= ＜ ,
There is a liquid level switch that responds quickly to changes in the liquid level in the liquid level switch (f-()) and has a responsiveness f1.

4. Figure 1 of the drawings shows the fruit of this invention/JI! Accepting the example (this is a schematic diagram, Figure 2 (
Figure 3 shows the resonance frequency characteristic 14 of the first piezoelectric vibration m = t]. The lower column shows the frequency characteristics of the second piezoelectric vibrator, and the middle column shows the output of the oscillator.
1: It can accept the output of electric vibration.

Claims (1)

[Claims] The first, second
The first JT +
The second amplifier and an oscillator (14) are used to detect the optical frequency change (J'C8k) of the oscillator, and the oscillation output of the oscillator is is applied to the second piezoelectric vibration -r, and the second piezoelectric vibration -'J]
The state of the resonant output of the child is the detection output. J. A liquid level switch characterized by sea urchin.