CN104454789B - A kind of field calibration method of electro-hydraulic servo valve test flow system flow parameter - Google Patents

Abstract

This method is the field calibration method of a kind of electro-hydraulic servo valve test flow system flow parameter；Use standard electric flow quantity servo valve that the lower range section of electro-hydraulic servo valve test flow system flow parameter carries out the field calibration of linearity error；Linearity error in the range of obtaining by calibration system flow parameter 10%～10%；There is compared with conventional calibration method the features such as easy and simple to handle, calibration cycle is short, data process is fast, ensure that by the concordance of calibration system align mode with the state of use simultaneously.

Description

A kind of field calibration method of electro-hydraulic servo valve test flow system flow parameter

Art

This technology belongs to flow measurement field, relates to the field calibration method of a kind of electro-hydraulic servo valve test flow system flow parameter.

Goal of the invention

The purpose of the present invention is as follows:

1, flow field calibration problem is solved；

2, the bidirectional linear calibration of electro-hydraulic servo valve test flow system flow parameter lower range section is realized；

3, the problem that the linearity error of electro-hydraulic servo valve test flow system flow parameter zero point cannot be calibrated is solved；

4, a kind of low cost, short cycle, simple and efficient on-the-spot flow calibration steps are found.

Background technology

Electro-hydraulic servo valve test system is developed specially according to electrohydraulic servo valve special technology condition, for testing the special equipment of flow valve various performance parameters.To the internal hemorrhage due to trauma of electro-hydraulic serving volume valve, zero partially, the important performance such as resolution, overlap test time, actual flow is less than the 10% of the electro-hydraulic servo valve test systematic survey upper limit, and for twocouese use.

Traditional calibration steps be effusion meter is removed after unload and send laboratory investment, there are the following problems for the method:

1, the required precision of effusion meter itself is higher, to reach to reach this, laboratory is generally selected by 10%～the 100% of the school flowmeter survey upper limit as its range ability, therefore gained linearity error does not comprise the lower range section particularly zero point of less than 10%, and the zero of valve product partially and internal hemorrhage due to trauma characteristic is all to record at zero crossings, zero point cannot be calibrated, just cannot ensure the accuracy of this feature measurement；

2, laboratory investment only carries out unidirectional calibration, and actually used for two-way, and align mode there are differences with use state；

3, the volume of effusion meter is big, Heavy Weight, and repeated disassembled and assembled and transport are not only difficult but also easily damage, and the censorship cycle is long, has a strong impact on product delivery progress.

In sum, in real work, the phenomenon that the test result of same deck valve product is differed greatly and can not pay in time because of system censorship product by different tests platform often occurs.

This programme is that emphasis solves two-way calibration, zero point and linearly calibrates for error and the problem such as field calibration.The capital equipment that the program is used includes standard electric flow quantity servo valve, static tester, test-bed body, X-Y recorder.Standard electric flow quantity servo valve output flow range is-the 10%～10% of scope of being measured by calibration system, maximum tolerance is less than by the 1/3 of calibration system maximum tolerance, meet volume passes requirement, and its repeatability and stability, all through making strict assessment, meet the condition as standardized product；Volume is little, lightweight simultaneously, it is simple to carry, and removes and installs conveniently, and pole is applicable to field calibration；This programme is simple to operate, and data process easy, quick, can directly obtain by the linearity error of school flow parameter lower range section, have extremely strong practical value.

Technical scheme: the standard electric specified output flow of flow quantity servo valve selected by this method is by the 10% of the calibration system flow measurement upper limit, because its range is little, therefore be substantially reduced with absolute error compared with calibration system, its maximum tolerance is less than by the 1/3 of calibration system maximum tolerance；Whole calibration process has only to the method for testing according to product, records the no load discharge output characteristics of standard electric flow quantity servo valve, slightly deals with gained characteristic curve, just can directly obtain by school flow parameter in the linearity error of this range section.Concrete operation step is as follows: the field calibration method of a kind of electro-hydraulic servo valve test flow system flow parameter, it is characterised in that comprise the following steps:

Step 1, standard electric flow quantity servo valve is correctly installed in electro-hydraulic servo valve test system, and static tester control signal output lead is connected with standard electric flow quantity servo valve terminals, flow simulation outfan is connected with X-Y recorder Y input, standard electric flow quantity servo valve current output terminal is connected with X-Y recorder X input terminal；

Step 2, regulation each valve of electro-hydraulic servo valve test system, electric switch, be set to no load discharge characteristic test state；

Step 3, regulation static tester are output as triangular signal, and amplitude corresponds to standard electric flow quantity servo valve rated current, and frequency is 1Hz, and then static tester is set to automatically export gear；

Step 4, by graph paper, be laid in X-Y recorder drawing area, centering is also fixed, and adjusts test pencil to origin position, adjusts X, Y-axis gear, make test pencil stroke take whole graph paper as far as possible；

Step 5, the triangular signal in control static tester one cycle of output, draw out the no load discharge characteristic curve in standard electric one cycle of flow quantity servo valve, and in winding shape, a cycle is-100% → 0 → 100% → 0 →-100%；

Step 6, drafting nominal flow capacity curve, the i.e. midpoint line of winding sigmoid curves, then with 100% rated current on no load discharge characteristic curve and-100% rated current corresponding point as end points, the straight line connecting two-end-point gained is name flow gain curve, reading nominal flow capacity curve and the maximum deviation of nominal flow capacity gain curve on graph paper, linearity error is calculated as follows:

${\mathrm{\λ}}_L=\frac{\mathrm{\Δ}{I}_{\mathrm{LM}}}{2I_n}\×100\%$

Wherein: λ_LLinearity error；

ΔI_LMNominal flow capacity curve and the maximum deviation of nominal flow capacity gain line；

I_nThe rated current of standard electric flow quantity servo valve；

Step 7, when gained linearity error less than this type valve product linearity allowable error time, i.e. can determine that this electro-hydraulic servo valve test flow system flow parameter-10%～10% range section linearity meet use requirement.

Beneficial effect:

When operating by this method, each ingredient of electro-hydraulic servo valve test system is in duty, is a kind of on-line calibration method, can guarantee that the concordance of align mode and the state of use；Simultaneously the most in a calibration process, the measurement apparatus such as the flow of electro-hydraulic servo valve test system, electric current, pressure, temperature and TT&C system are required to participate in, and have both calibrated the flow parameter of electro-hydraulic servo valve test system, and have been able to verify that again its combination property, and had killed two birds with one stone；

Use the calibration of standard electric flow quantity servo valve, it is not necessary to dismounting effusion meter, easy and simple to handle, the most reliably, utilize on-the-spot oil sources to realize calibration, not only economize on resources but also reduce calibration difficulty, moreover it is possible to be greatly shortened prover time；

Standard electric flow quantity servo valve volume is little, lightweight, it is simple to carry, it is not necessary to other planning standard equipment, is extremely suitable for field calibration.

Detailed description of the invention:

In the inventive method, specifically there is a feature highlighted below:

1, use standard electric flow quantity servo valve that electro-hydraulic servo valve test flow system flow parameter is carried out field calibration；

2, the specified output flow of standard electric flow quantity servo valve is 10% reached the standard grade by calibration system measurement；

3, the no load discharge characteristic curve of standard electric flow quantity servo valve is drawn, it is achieved calibrated by the bidirectional linear of school flow parameter；

4, the no load discharge characteristic curve of standard electric flow quantity servo valve, by zero point, therefore can obtain the linearity error at zero point；

5, using X-Y recorder to carry out data record, process in graph paper enterprising row data simple, quick, linearization error value can directly read and obtain.

The each critical component used is described below:

Static tester: be made up of parts such as direct current amplifier, digital-to-analogue conversion amplifier, differential amplifiers, for Flow Characteristics of Electrohydraulic Servo Valve, the display of pressure characteristic, change and export, and the test equipment of DC current needed for performance test is provided for electrohydraulic servo valve.

Test-bed body: develop specially for electro-hydraulic serving volume valve performance test, imitates the test equipment of valve product actual condition；The tested media with certain pressure and flow is provided for tested valve product；And possess flow, pressure, temperature test and output function.

X-Y recorder: be again pen recorder, can be depicted as function curve by the analogue signal of input.In this method, draw the no load discharge characteristic curve of standard electric flow quantity servo valve with it.

Choose a particular situation below, the detailed description of the invention of the present invention be described in detail as follows:

By school electro-hydraulic servo valve test system:

Model: SC09；

Measure the upper limit: 150L/min；

Maximum tolerance: 1.5L/min；

Standard electric flow quantity servo valve

Model: FF102/10

Metered flow: 10L/min

Maximum tolerance: 0.4L/min；

Rated current: 10mA；

Linearity error: be not more than 4%

Step 1, standard electric flow quantity servo valve is correctly installed in electro-hydraulic servo valve test system, and static tester control signal output lead is connected with standard electric flow quantity servo valve terminals, flow simulation outfan is connected with X-Y recorder Y input, standard electric flow quantity servo valve current output terminal is connected with X-Y recorder X input terminal；

Step 2, open electro-hydraulic servo valve test system oil inlet valve, oil return valve is opened to maximum, opens static tester, and its test parameter selection knob is adjusted to " Q-I " state, observes static tester upward pressure, temperature, flow indication the most normal；

Step 3, regulation static tester are output as triangular signal, and output amplitude is 10V, is 10mA corresponding to standard electric flow quantity servo valve rated current, and frequency is 1Hz, and then static tester is set to automatically export gear；

Step 4, it is the graph paper of 1mm by 20cm × 40cm, minimum indexing lattice, it is laid in X-Y recorder drawing area, fixing after centering, adjust test pencil alignment origin position, adjusting X-axis gear makes its resolution be about 0.5mA/cm, adjusts Y-axis gear and makes its resolution be 1L/min/cm；

Step 5, start test, control static tester output triangular signal, output order be-100%I_n→ 0 → 100%I_n→ 0 →-100%I_n, draw out the no load discharge characteristic curve in standard electric one cycle of flow quantity servo valve, in winding shape；

Step 6, drawing out nominal flow capacity curve and nominal flow capacity gain curve, it has been observed that maximum deviation is positioned at output flow is at 0.8L/min, read the maximum deviation of two curves herein differs about 4 minimum indexing lattice, being calculated the linearity error at this is:

${\mathrm{\λ}}_L=\frac{4\×10/200}{2\×10}\×100\%=1\%$

I.e. its linearity error is less than the linearity error permissible value of this type valve product, i.e. can determine that this electro-hydraulic servo valve test flow system flow parameter-10%～10% range section linearity meets and uses requirement.

Whole experimentation has two people to coordinate, do not remove the electro-hydraulic servo any equipment of valve test system, again by electro-hydraulic servo valve test system recovery to upstate used time 1.5 hours altogether from preparing to reaching a conclusion, the ruuning situation observing each measurement equipment therebetween is the most normal.

In electrohydraulic servo valve product submitted for test later, electro-hydraulic servo valve test stable system performance, valve product zero partially, the characteristic curve such as internal hemorrhage due to trauma, resolution clear and legible, result of the test is the most credible, obtains client's accreditation.

Claims (1)

1. the field calibration method of an electro-hydraulic servo valve test flow system flow parameter, it is characterised in that bag Include following steps:

Step 1, standard electric flow quantity servo valve is correctly installed in electro-hydraulic servo valve test system, and will Static tester control signal output lead is connected with standard electric flow quantity servo valve terminals, and flow simulation exports End is connected with X-Y recorder Y input, standard electric flow quantity servo valve current output terminal and X-Y recorder X input terminal is connected；

Step 2, regulation each valve of electro-hydraulic servo valve test system, electric switch, be set to zero load Discharge characteristic test mode；

Step 3, regulation static tester are output as triangular signal, and amplitude is watched corresponding to standard electric flow quantity Taking valve rated current, frequency is 1Hz, and then static tester is set to automatically export gear；

Step 4, by graph paper, be laid in X-Y recorder drawing area, centering is also fixed, adjust test pencil To origin position, adjust X, Y-axis gear, make test pencil stroke take whole graph paper as far as possible；

Step 5, the triangular signal in control static tester one cycle of output, draw out standard electric liquid stream The no load discharge characteristic curve in amount one cycle of servo valve, in winding shape, cycle is-100% → 0 → 100% → 0 →-100%；

Step 6, the midpoint line of drafting nominal flow capacity curve, i.e. winding sigmoid curves, then with zero load stream On rating curve, 100% rated current and-100% rated current corresponding point are end points, connect two-end-point gained Straight line be name flow gain curve, graph paper reads nominal flow capacity curve and nominal flow capacity gain bent The maximum deviation of line, linearity error is calculated as follows:

${\mathrm{\λ}}_L=\frac{\mathrm{\Δ}{I}_{\mathrm{LM}}}{2I_n}\×100\%$

Wherein: λ_LLinearity error；

ΔI_LMNominal flow capacity curve and the maximum deviation of nominal flow capacity gain line；

I_nThe rated current of standard electric flow quantity servo valve；

Step 7, when gained linearity error less than this type valve product linearity allowable error time, i.e. can determine that this Electro-hydraulic servo valve test flow system flow parameter-the 10%～10% range section linearity meets use requirement.