Displacement transmitted large rate microform and vibratory string different variation mechanism
The present invention relates to a kind of type vibration wire displacement transducer, particularly a kind of type vibration wire displacement transducer large rate microform and displacement difference dynamic sensor structure of being used for.
Sensor be can bear the specified measuring range amount and according to certain rule convert to can output signal device, existing type vibration wire displacement transducer mostly adopts spring as the first displacement receiving element, the conversion of---power---displacement that the displacement of spring one end is done displacement through spring body, the other end at spring obtains a proportional less displacement, vibratory string obtains the displacement of an equivalent thus, and portion obtains a corresponding STRESS VARIATION within it, exports a corresponding vibration frequency value of STRESS VARIATION therewith through electrical converter.Since spring shaft to intrinsic entity size, when meeting great-scale displacement output, the axial dimension of spring will be very big, add upper spring self and have twice linear error in the existence of---power---displacement conversion in displacement, simultaneously presence bit moves past in the journey adverse effect because of factors such as frictional resistance, and all multifactor restrictions such as quality problems in the spring manufacturing process.Therefore, (it is unstable that 100～500mm) displacement transducers exist long-term use inevitably, and repeatability is poor, and nonlinearity is big, open defects such as poor sensitivity for existing wide range.Simultaneously, traditional displacement transducer is finished by spring because of the displacement transmission, and all is that smooth single sensing element realizes that induction changes, thereby the measurand temperature influence can't be eliminated.Vibrating string type sensor working film after the improvement is provided with the string wire of its insulation and eliminates the measurand temperature influence, " vibrating-string type single-coil current sensor and energizer " (number of patent application: 98122129.7) of Inst. of Instruments, Shandong Mining College invention for example, its structure is the string wire that has on the working film in housing with its insulation, next door, string wire middle part is provided with a magnetic induction loop, the two ends of string wire and the two ends of coil are connected in respectively on the energizer of being made up of elements such as differential amplifiers, and energizer is arranged in the secondary instrument or is arranged in the housing; Its advantage is that the working sensor electric current is very little, and string can be very short, and volume can be very little, and no frequency multiplication is disturbed, reliability height, but complex structure, and manufacture difficulty is big, and incompatibility is used for wide range.
The purpose of this invention is to provide a kind of measured value (zero point and measurement range) long-term stability, good reproducibility, nonlinearity is little, great-scale displacement sensor highly sensitive, simple in structure, particularly displacement transmitted large rate microform and vibratory string different variation mechanism.
The present invention realizes like this, in the housing of sensor, be provided with two groups of differential change vibratory string experience same displacement input quantity, concrete structure is: a slope is set in the housing of sensor, be provided with the displacement axis of rolling in the slope, coaxial lever A and the lever B of being with of the axis of rolling, the other end of lever A and lever B respectively has a balance pivot, and moving axially by rigid displacement transmission bar of lever A and lever B and the displacement axis of rolling transmitted; The balance pivot place of lever A and lever B is provided with string wire, and the other end of string wire and signal excitation and pick device connect firmly, and signal excitation and pick device are exported signal by output line; Be provided with seat in the housing, be used for determining the axial location of other part in the housing.Owing to have lever A and lever B in the slope, to roll respectively by the displacement axis of rolling, produce differentially in the transmittance process, therefore, transmittance process does not have potent influence, can not be subjected to all multifactor influences such as friction force, temperature yet.
Below in conjunction with accompanying drawing the present invention is further described.
Accompanying drawing is the structural representation of one of the utility model embodiment.
Accompanying drawing is one embodiment of the present of invention, and 1 is that rigid displacement transmits bar, the 2nd, the displacement axis of rolling, the 3rd, lever A in the accompanying drawing, the 4th, lever B, the 5th, balance pivot, the 6th, be signal excitation and pick device, 7 string wires, the 8th, output line, the 9th, slope, the 10th, sensor housing, the 11st, seat.
In the housing (10) of vibrating string type sensor, be provided with two groups of differential change vibratory string experience same displacement input quantity, concrete structure is: in the housing (10) of sensor a slope (9) is set, be provided with the displacement axis of rolling (2) in the slope (9), coaxial lever A (3) and the lever B (4) of being with of the displacement axis of rolling (2), the other end of lever A (3) and lever B (4) respectively has a balance pivot (5); Moving axially by rigid displacement transmission bar (1) of lever A (3) and lever B (4) and the displacement axis of rolling (2) transmitted; The balance pivot (5) of lever A (3) and lever B (4) locates to be provided with string wire (7), and the other end of string wire (7) and signal excitation and pick device (6) connect firmly, and signal excitation and pick device (6) are exported signal by output line (8); Housing is provided with seat in (10), and (11) are used for determining the axial location of other part in the housing (10).Owing to have lever A (3) and lever B (4) in slope (9), to roll respectively, produce differential in the transmittance process by the displacement axis of rolling (2).The miniature mechanism of secondary mechanical of connecting with lever A (3) and lever B (4) through slope (9) transmits the miniature effect of realization 〉=1000: 1, quote this structure, thoroughly abandoned traditional elastic body enlarger, changing original mechanism, to be difficult to reach wide range miniature, and realized that the constant force displacement transmits, effectively improved the technical indicators such as linearity, composition error of sensor simultaneously.Adopt this structure also can conveniently realize the principle of differential sensing, the sensitivity of sensor is doubled, temperature effect is fallen at the end greatly, is one of current ideal wide range sensor.
