Detailed description of the invention
Below in conjunction with the accompanying drawings embodiments of the invention are described in detail.
The present invention is to utilize two rotary angle stroke double-acting pneumatic actuators as double acting intelligent valve positioner 1
The air pressure-loading valve positioner testing stand of test load.
This testing stand includes a controlling organization pneumatic actuator 2 the most supporting with tested intelligent valve positioner 1,
The air pressure loading system that one small-sized executor reversely used simulating the load of controlled valve is constituted, also includes one for soon
Speed connects the gas circuit quick assembling mechanism of the air cavity of pneumatic actuator 2 and the air-path interface of tested valve door holder 1, and one is used for eliminating
The elimination return difference mechanism in gap is turned round between tested valve door holder and pneumatic actuator.
As shown in Figure 1 and Figure 2, its principle is the structure of rotary angle stroke double-acting pneumatic actuator, cylinder two-chamber A/B
Between pressure reduction promote piston, and the moment of torsion output of rotary shaft thrust become by rack geared, and then band movable valve
Carry out corresponding spinning movement.Fig. 1 represents counterclockwise rotation, and compressed air is inputted entrance center by A mouth, makes left and right piston
Moving in outward direction, rotary shaft counterclockwise rotates, and the air outside two-piston is discharged by B mouth;Fig. 2 represents side clockwise
To rotation, compressed air is entered both sides by the input of B mouth, makes left and right piston move to center, and rotary shaft is rotated clockwise, and two
Air in the middle of piston is discharged by A mouth.
The mounting structure of testing stand is as shown in Figure 5.Tested valve door holder 1 is placed on a sheet metal structural support 23,
Support fastened by screw is on pneumatic actuator 2.Select the rotary angle stroke pneumatic executor 2 of cylinder diameter 210mm fixed with valve
The position supporting connection of device 1, the resetting shaft of tested valve door holder 1 bottom rotates with the output of rotary angle stroke pneumatic executor 2
The upper end of axle connects, it is to be noted that the rotary shaft of pneumatic actuator to be ensured 2 is concentric with the resetting shaft of valve positioner 1.
For the simulated field various pipeline flow of controlled valve, the rotary angle row selecting another cylinder diameter to be 105mm
Journey pneumatic actuator reversely uses, and constitutes reverse execution device 3.The rotary shaft of reverse execution device controls with tested valve door holder 1
Pneumatic actuator 2 output rotary shaft lower end connect, to reverse execution device air cavity provide adjustable loading air pressure, be used for
The various pipeline flow of the controlled valve of simulated field, as the mechanical load of pneumatic actuator 2 during test.Double acting is pneumatic
One critically important feature of executor is, under constant air pressure, in whole rotary course, moment of torsion keeps constant.So this load
Just the demand of test is met.
As it is shown in figure 5, use the square tube of 100 × 100 to do Change-over frame 24 in echelon, reverse execution device 3 is inverted
In lifting testing stand, it is positioned at the underface of pneumatic actuator 2.The bottom of the rotary shaft of pneumatic actuator has an anise to sink
Hole, is suitable for placing foursquare axle, can be spaced 45 ° and put into.The anistree counterbore of the rotary shaft upper end of reverse execution device 3, the most right
The anistree counterbore of the rotary shaft bottom of pneumatic actuator 2.Make a foursquare bridge shaft, by the rotation of two pneumatic actuators
Axle couples together, and notes ensureing that two pneumatic actuator rotary shafts are concentric.
When the rotary shaft of pneumatic actuator 2 rotates motion, the rotary shaft of reverse execution device 3 will be driven to revolve together
Turn.It is passed through constant air pressure at this moment to the corresponding air cavity of reverse execution device 3, causes constant reactive torque to rotating, be the formation of
The constant load of process of the test.
The system block diagram of testing stand is as it is shown on figure 3, regulate the signal source (4~20mA) of detection case, tested valve door holder 1
By the deviation size and Orientation of the actual value according to pneumatic actuator 2 rotary shaft corner with the set-point of detection case output, output
Corresponding control command, is i.e. converted into gas signal and controls the electric conversion module of tested valve location by controlling the signal of telecommunication, and by
Electric conversion module output gas signal drives air inlet or the aerofluxus of pneumatic actuator 2 two-chamber A/B.And according to pneumatic actuator 2
Mechanical position feedback, tested valve door holder 1 controls the air inlet of given pneumatic actuator 2 two-chamber.Pneumatic actuator 2 is due to internal
Two-chamber A/B enters the pressure reduction of gas so that it moves clockwise or counterclockwise.
In input air pressure path, before test regulation component 4 is connected to double-purpose valve door holder 1, play simulated field
Situation during various air pressure, usual 0.4~7Bar is adjustable.Before load regulation component 5 is connected to reverse execution device 3, play tune
The effect of the size and Orientation of the reactive torque of joint reverse execution device 3.
As shown in the pneumatic schematic diagram of Fig. 4 embodiment, source of the gas accesses testing stand from 2/2-way manual ball valve 8, then divides
Three tunnels are respectively supplied to the Direct Travel cylinder 19 of gas circuit quick assembling mechanism 6, tested valve door holder 1 and the controlled valve operating mode of simulation
The reverse execution device 3 of air pressure loading system.
Source of the gas the first branch enters Direct Travel cylinder 19 by a 3-position 4-way hand-operated valve 18.3-position 4-way hand-operated valve 18
Air inlet P can the switching of two states be connected with two plunger shaft of Direct Travel cylinder 19 respectively.
When P-A path connected by 3-position 4-way hand-operated valve 18, the piston big chamber A air inlet of Direct Travel cylinder 19, air pressure promotes
Piston advances forward, the B-R path that the piston loculus B of Direct Travel cylinder 19 is connected by 3-position 4-way hand-operated valve 18 is outwardly arranged
Gas;When P-B path connected by 3-position 4-way hand-operated valve 18, the piston loculus B air inlet of Direct Travel cylinder 19, air pressure promote piston to
Rear motion, the A-R path outwardly aerofluxus that the piston big chamber A of Direct Travel cylinder 19 is connected by 3-position 4-way hand-operated valve 18.
A gas contiguous block 20 is connected, in test job, by manipulation three in the piston rod front end of Direct Travel cylinder 19
Four-way hand-operated valve 18, straight stroke air cylinder 19 just can quickly promote and retract gas contiguous block 20 so that gas contiguous block 20 is with tested
Pressing of valve positioner 1 connects and sharp separation, installs the workload of tested valve door holder 1 sum, also drop before reducing test
Low each installation tested valve door holder 1 will reconnect the workload of gas circuit.
Source of the gas the second branch enters double-purpose valve door holder 1.
As shown in Fig. 4 pneumatic schematic diagram, source of the gas, before supply tested valve door holder 1, is introduced into the defeated of regulation component 4
Entering end, the outfan of regulation component 4 is connected with the air pressure input port of tested valve door holder 1.Three gas of regulation component 4 parallel connection
The low pressure gas circuit of road, respectively low pressure regulating pressure valve 10 and low tension switch 9 series connection, middle pressure pressure regulator valve 12 and Medium voltage switch or circuit breaker 11 series connection
Middle pressure gas channel, source of the gas and the straight-through high-pressure gas circuit of high-voltage switch gear 13.Select to be suitable for by three baroswitches in three gas circuits
Test air pressure.
Test air pressure is introduced into tested valve door holder 1, and valve positioner 1 controls to enter 2 two air cavitys of pneumatic actuator
The air pressure of A/B.Valve positioner 1 is by detecting the machine feedback of pneumatic actuator 2 so that pneumatic actuator 2 is positioned at one
Given position.
The time length difference that three kinds of different test air pressure plays to make pneumatic actuator move to anchor point, observable valve
Door holder 1 to control and feedback signal gather hysteresis and sensitivity.
In order to improve the testing efficiency of testing stand, the several pressure of Test-bed Design, low pressure, medium and high pressure be set as respectively
2Bar, 4Bar and total head (7Bar).Although this function can be got final product easily by the given signal of telecommunication by a current to pneumatic converter
Switching, and also each little variable quantity air pressure can be obtained.But the price of a usual electric converter is common more than 10
Air relief valve, and actual test is not required to diversified air pressure, as long as so consider low pressure that simulated field is likely to occur, in
Pressure, high pressure are designed, and need not add air relief valve again under high-pressure situations, lead directly to just.Calm the anger basic, normal, high
Road is loaded onto air circuit breaker respectively, can open or close the most respectively.
In order to identify the air pressure being actually reached tested valve door holder 1, we have installed a Pressure gauge 14 additional determined
In gas circuit before the device of position, convenient reading actual pressure value.
1 two air pressure interfaces of tested valve door holder connect respectively the filling of two air cavity A/B air pressure of pneumatic actuator 2,
Venting, controls the pressure of two air cavity A/B of pneumatic actuator 2 by valve positioner 1.For observing tested valve door holder 1
Output is to the atmospheric pressure value of the A/B air cavity of pneumatic actuator 2, at tested valve door holder output pressure to the two of pneumatic actuator 2
Gas circuit designs two air gauges 21,22.And separately design gas vent in this two gas circuit, and accessing two air circuit breakers 25, it is made
With being: after having tested, quickly the air pressure in the A/B air cavity of pneumatic actuator 2 is discharged, it is to avoid when unloading valve positioner
There is the huge sound in the release of this air pressure, blows away some gas circuits and seal finding, such as O etc..
Source of the gas the 3rd branch has entered the reverse execution device 3 of reactive torque.
The load pressure regulator valve 15 first passing through load regulation component 5 adjusts bleed pressure and obtains stable air pressure, air pressure now
Value can be read out by Pressure gauge 16, is then determined the phase entering reverse execution device 3 by two five-way hand-operated direction valves 17
Answer air cavity, so that it is determined that the reactive torque that reverse execution device 3 causes for pneumatic actuator 2.
According to the direction of motion of actual pneumatic actuator 2, determine to give the direction of reverse execution device 3 air pressure.Such as Fig. 4 institute
Show, when valve positioner 1 drives pneumatic actuator 2 to rotate counterclockwise, hand-operated direction valve 17 pull P mouth to A mouth ventilate, B mouth to
EB mouth aerofluxus, reverse execution device 3 loads clockwise.When valve positioner 1 drives pneumatic actuator 2 to turn clockwise, hands
Dynamic reversal valve 17 is pulled P mouth and is ventilated to B mouth, and A mouth counterclockwise loads to EA mouth aerofluxus, reverse execution device 3, reverse execution device
The reactive torque of 3 pairs of pneumatic actuators 2 is constant.And air pressure constant, reactive torque is constant.
As shown in Figure 6, Figure 7, for reducing the time installing tested valve door holder 1, improving production efficiency, this testing stand sets
Put a gas circuit quick assembling mechanism 6 quickly connecting tested valve door holder air-path interface.The right of tested valve door holder 1 uses one
Individual Direct Travel cylinder 19, compresses and loosens the gas contiguous block 20 that the air pressure interface with localizer is in close contact by it, reduces
Tested valve door holder 1 is installed every time and will again connect the workload of gas.
This gas circuit quick assembling mechanism 6 is main by the gas contiguous block 20 being connected with two air cavity A/B of pneumatic actuator 2,
Quick-installation bolt 27, cylinder contiguous block 29, for being switched fast the intermediate mass 28 for different size measured piece, Direct Travel cylinder 19
Form with 3-position 4-way hand-operated valve 18.Wherein Direct Travel cylinder 19 and the combined integrated use of 3-position 4-way hand-operated valve 18, i.e. pass through
3-position 4-way hand-operated valve 18 directly controls the motion mode of Direct Travel cylinder 19.
According to aforementioned source of the gas the first branch, in tested localizer installation process, if as it is shown in fig. 7, manually pulling three four
When the handle of logical hand-operated valve 18 is toward H position, the A air inlet of Direct Travel cylinder 19 piston big chamber, piston loculus B aerofluxus, air pressure promotes piston
Motion, the piston rod of Direct Travel cylinder 19 promotes gas contiguous block 20 to compress tested valve door holder 1, two of valve positioner 1
Air pressure interface is connected with two air cavity A/B of pneumatic actuator 2 respectively by gas contiguous block 20.If manually pulling 3-position 4-way hands
When the handle of dynamic valve 18 is toward Q position, Direct Travel cylinder 19 piston loculus B air inlet, the A aerofluxus of piston big chamber, air pressure promotes piston reverses direction
Motion, the piston rod of Direct Travel cylinder 19 pulls gas contiguous block 20 to depart from tested valve door holder 1.
Owing to tested valve door holder has band Pressure gauge assembly and the specification without Pressure gauge assembly, therefore by whether install additional
The intermediate mass 28 of quick assembling mechanism 6, i.e. can be used to calibration tape Pressure gauge assembly and the specification valve positioner without Pressure gauge assembly
1.Concrete operations are: if tested localizer is without Pressure gauge assembly, then this quick assembling mechanism is installed as shown in Figure 6, Figure 7.If
Tested localizer band Pressure gauge assembly, the most first extracts Quick-installation bolt 27, then is taken out by intermediate mass 28, then directly by cylinder even
Connect block 29 to insert in gas contiguous block 20 pilot hole, then lock, as shown in Figure 8 and Figure 9 with a Quick-installation bolt 27.
Due to the existence of manufacturing and fixing error, the resetting shaft of tested valve door holder 1 and the rotary shaft of pneumatic actuator 2
Between have fit clearance, then will necessarily produce test return difference.Return difference hour, does not have the biggest problem, very during stand-alone debugging
To being not discovered.When reaching one, two percentage points, just it is very easy to find at valve wide open closed positions, shows as, actual valve
Position has arrived at but value of feedback but shows the most far short of what is expected.Such as it is found problems when debugging, should process in time, once throw
Enter to run, during onsite application, in the workshop section that technological requirement is higher, oscillatory occurences easily occurs.
Given this phenomenon, testing stand arranges just like the elimination return difference mechanism 26 shown in Figure 10, Figure 11, Figure 12, is used for eliminating
The return difference produced in test process.In tested valve door holder 1 installation process, the resetting shaft of localizer 1 is by eliminating return difference machine
Structure 26 is connected with the rotary shaft of pneumatic actuator 2.During installation, first will eliminate the locating shaft base 31 of return difference mechanism with a screw 30
It is fixed on the top of the rotary shaft of pneumatic actuator 2, then with 2 alignment pins 32, spacing locating shaft 33 is installed at the bottom of locating shaft
On seat 31.2 alignment pins 32 all have close-fitting requirement with locating shaft base 31 and spacing locating shaft 33, locating shaft base of ascending the throne
31 can not have gap and relative rotation after the installation of spacing locating shaft 33.
The action principle of return difference mechanism 26 is: the resetting shaft of tested valve door holder 1 inserts spacing locating shaft 33 top
In circular hole, acting on the lower end of compact heap 34 by the elastic force of stage clip 35, the upper end of compact heap 34 compresses tested valve location
The resetting shaft of device 1.Therefore i.e. without rotating against between resetting shaft and the spacing locating shaft 33 of tested valve door holder in test process,
Test return difference is eliminated.
The power supply of valve positioner 1 and signal feeding, signal feedback are controlled by the detection case 7 of testing stand upper left side and show
Show.Detection case 7 is mainly made up of a signal source, and the electric control signal of the exportable 4-20mA of this signal source is used for controlling tested valve
The location of door holder 1, meanwhile, the actual position value that controlled valve feeds back is believed by the output of tested valve door holder 1
Number also show on this detection case 7.Figure 13 is the tested valve door holder 1 that the detection case 7 with the embodiment of the present invention is connected
The logic block-diagram of control circuit.
A, the operation principle of tested valve door holder 1
As shown in figure 14, intelligent valve positioner 1 operation principle is to compare set-point and controlled by Micro-processor MCV
The actual value that valve feeds back, and utilize deviation signal to control to enter the air inflow of pneumatic actuator air cavity, thus reach
To being accurately positioned.
Micro-processor MCV receives the set-point signal of 4-20mA, with the actual valve of the position sensor feedback of controlled valve
Place value compares, if be detected that deviation, exports an automatically controlled instruction to two controls according to the size and Orientation of deviation immediately
Valve processed, one of them control valve air inlet, another control valve aerofluxus, thus regulate the air mass flow entering actuator air chamber,
It is to say, control instruction is converted into pneumatic displacement increment by control valve.(the height when actual valve position and setting value deviation are the biggest
Speed district), valve positioner 1 exports a continuous signal, controls its electric conversion module and inflates toward executor's air cavity continuously or put
Gas, makes valve position quickly near setting value;As deviation is little (low regime), valve positioner 1 is by output pulse signal;When deviation very
Hour (self adaptation or adjustable dead band state), then do not have framing signal to export, and now, actual controlled valve arrives setting value, machine
Structure reaches poised state, the corresponding certain valve location of the most certain setting value electric current.
Even if valve positioner testing stand is installed controlled valve and also is difficult to arrange such as on-the-spot various pipeline flows, institute
As long as typically to simulate controlled valve to the moment used by an off under various flow effects.
In order to simulate real work situation, valve flow load selects a miniature pneumatic executor reversely to install, its machine
The rotary shaft of tool outfan uses as mechanical input, referred to as reverse execution device 3, also gives a stable air pressure, as
The load of pneumatic actuator 2.Because may there be difference, mould the time that pneumatic actuator 2 bringing onto load runs with the no-load running time
Intend real work situation and be more beneficial for testing hysteresis and the susceptiveness of product.
When test, give tested localizer 1 accurate according to the logic block-diagram of Figure 13 tested valve door holder 1 control circuit
Connect wire, and to the logical upper source of the gas of testing stand, the signal source of regulation detection case 7 gets final product the function of simulation test valve positioner 1.
B, valve positioner 1 Function detection
Whether met by this test assessment product basic function, can normally work.
Detection project: the Shou automatic switching function of valve positioner 1, Zheng reverse function, Duan Qi signal holding function,
Warning function, self-diagnostic function.
Test procedure:
A. press valve positioner 1 hands automatically switch, audit function is the most normal.
B., after correct wiring, make valve positioner 1 total travel run, input signal 0%, 25%, 50%, 75%,
100%, carry out a circulation, observe pneumatic actuator 2 and the operation conditions of reverse execution device 3.
C. sudden shut off input signal, observe whether valve positioner 1 keeps.
D. sudden shut off source of the gas, observe whether valve positioner 1 keeps.
E. the self diagnosis flow process of valve positioner 1, the parameters of record self diagnosis are run.
F. run valve positioner 1 self-defined valve characteristic curve function time, by curve mistake be defined as non-monotonic
Rise decline, observe the most correct display alarm of valve positioner 1.
When g. initializing, by parameter error be arranged to prescribed limit outside, observe valve positioner 1 the most correctly show
Report to the police.
H., during input > 100% or <-10% signal, the most correct display alarm of valve positioner 1 is observed.
I. make valve positioner 1 stall when not arriving appointment position, observe valve positioner 1 and the most correctly show report
Alert.
Note: a be hands automatic functional testing;B be positive reverse function test;C-d for die break signal keep function survey
Examination;E is self-diagnostic function test;F-i is warning function test.If valve positioner 1 does not has alarm module, do not report to the police
Functional test.
C, valve positioner 1 linearity, cardinal extremity conformity error, repeatability error detects
By regulating the signal source of detection case 7, changing input signal, the amplitude with 10% is in direction up and down extremely
Test three times, record the output signal value that each input point is corresponding less, the error amount recorded according to each testing site, computational accuracy
(repeatability error), return difference.
During experiment, input signal should approach testing site slowly by the same direction of initial change, was not allow for punching existing
As.During test, input signal should keep stable, until tested parameter stability.
D, valve positioner 1 step response test
The signal source of regulation detection case 7, applies a series of Spline smoothing signal in the input of valve positioner 1, with
Compared by the response time of electricity testing device.
E, valve positioner 1 input signal cross range detection
A. will be adjusted to 28mA by valve positioner 1 input signal, for time 1min, observe valve positioner 1 overburden shape
State.
B. return to the 50% of input range, after stablizing 5min, measure exporting change amount.
C. input signal is adjusted to zero, repeats above-mentioned test, measure exporting change amount.
The functional parameter of the test bed embodiment of valve positioner of the present invention:
1. basic function
A, detection valve positioner various functions parameter
B, the detection valve positioner linearity, cardinal extremity conformity error, repeatability error
C, detection valve positioner step response
Scope test crossed by D, valve positioner
2. specifications parameter
Overall dimensions |
700W × 300D × 400H (without detection case) |
Detection case size |
235W×165D×160H |
Air pressure range |
0~7Bar |
Gas source connector |
G1/4 |
Use voltage |
220VAC |
Control mode |
Local operation controls |
Corresponding to the rotary angle stroke double-acting pneumatic actuator originally tested valve door holder that the present invention uses
The controlled object of configuration, is that any valve positioner manufacturer is as standard articles essential to Simulation field test.
Use the adjustable constant load of conduct of a small size double acting pneumatic actuator, the energy and tested mechanism controls
Object identical, it is not necessary to another oil (gas) filling device.Standardized product, moderate, design and installation is convenient, and compact conformation is suitable for 90 °
The perfect load mode that rotary test uses.
The key point of the present invention is to utilize double acting pneumatic actuator moment of torsion during whole execution to keep constant
Specific, as the constant load in process of the test, by adjusting bleed pressure, it is achieved load change.
Rotary angle stroke double-acting pneumatic actuator, is the conventional products in pneumatic actuator, and this testing stand is to gas
The reverse utilization of dynamic executor's operation principle, double pneumatic actuator superpositions use, and technology is single, uses more convenient.