Summary: The article puts forward the synchronism of much oil cylinder of a kind of long distance to check new method, replace sensor of traditional and many Cheng absolutely displacement measurement technique, realized real time to detect, practice makes clear, the method is direct, reliable, have value of remarkable technology economy and wide application perspective. The test job that synchronism of 1 introductive hydraulic pressure runs is very main, because this is the method that assesses to the science of systematic performance, the installation at an early date that also is pair of place development is exposed be handled blemish, in time or improve, improve quality, ensure the practical and significant important step of dependability. Because test job is,undertake below imitate operating condition, can utmost ground the element that fails to consider in the design " join " in the experiment, technical economy value nots allow to ignore. The application of system of long distance oil cylinder is very wide, special use in large, heavy equipment extremely general (if large clough hoist, marine project, engineering is mechanical,wait for) . Load of equipment moving China and foreign countries always is in lopsided with random change condition, the synchronous demand to long distance oil cylinder is so high, cause equipment performance otherwise inferior, serious even damage, break down invalidation. To growing journey much oil cylinder, if use traditional method to undertake be measuringed to displacement absolutely detecting, must use the displacement sensor of a large number of Cheng, economy of apparent both neither, installation is very difficult also, incommensurate imitate test reachs the need that the spot detects. Via old research and practice, the synchronous moving position that the article raises to undertake length journey much oil cylinder with relative standard is online detect, obtain favorable result in scientific research and manufacturing practice at present, narrate as follows to the point. If the graph is shown 1 times,sensor of system of test of synchronism of principle of 2 tests job and join of synchronous oil cylinder decorate working principle. This system checks the grating sensor that uses smallish route to serve as detecting element relative to displacement. Grating displacement sensor by scale 7 with head of reading of slide 8 () composition, scale and slide are installed respectively go up in lever of piston of different oil cylinder, when the system works, scale and lever of piston of slide be accompanying move together. When synchronism of lever of piston of two oil cylinder moves, did not move relatively between scale and slide, reading head does not have signal output; When different situation runs staff of piston of two oil cylinder, there is opposite campaign between scale and slide, reading head has output of displacement error signal. Graph in 1 moving process, to protect grating deputy will not damage as a result of accident reason, the security that designed grating protects a structure. Graph 1 in, 1 the canister that it is a crock, magnet 4, join board 3 with piston lever 2 fixed coupling, scale 7 with piston lever 9 fixed join, as a result of magnet 4 with guide magnetism board the magnetism attraction of 5 generation, slide 8 will follow piston lever 2 motion. Make lever of piston of two oil cylinder opposite when accident reason when displacement is bigger, guide slide of magnetism board 5() come up against block iron 6 and cannot continue to move, and magnet 4, join board 3, piston lever 2 because secure coupling to continue to move,cause magnet 4 with guide magnetism board 5 break away from a contact, protected grating deputy safety. In the test, degree of consistency of moving position of staff of piston of two oil cylinder is interested most, also be the most essential problem, afore-mentioned methods can perfect the synchronism of long distance much oil cylinder to check system testing to ask. The exchange of 3 signal pursues 2 it is signal commutation and computer detect principle block diagram. The displacement signal that reading head outputs is sine wave, and signal is weaker, detect plant shift circuit needs according to actual application, should have following basic signal to handle a function: The enlarge processing of faint signal, rise defend oneself the argue of displacement of direction of positive and negative of feet of the fractionize circuit of rate, divisional grating writes down number to show circuit, improvement to what circuit, real time observes what systematic dependability and signal protect a function is absolutely the circuit such as 0 potential. Handle concerned technology point to discuss as follows with respect to grating signal now: Graph argue of 2 fractionize to form circuit with pulse: Grating feet has very high reticle density, the 25 lines that introduce like this system / Mm, the requirement is obtained detect taller defend oneself rate, use little bar to be apart from, transparent technology difficulty is mixed is not economical economically. Use electronic fractionize technology to rise defend oneself leading is to use the widest method at present, have the fractionize method such as fourfold frequency, bridge, phasic modulation, Suo Xiangpin commonly usedly. This system uses fourfold frequency direct fractionize law, it is the signal that is 90 ° through two when grating sensor outputs phasic difference, the course is differential, get 4 phasic difference ordinal the pulse signal that is 90 ° , implementation rises defend oneself rate. To 25 lines / the grating of Mm is attainable digital reading of 10 μ M defend oneself rate, can satisfy the requirement that synchronous precision tests. Move in synchronous system in, oil cylinder way of shift of two pistons lever is opposite at null be change, for differentiate shift direction (the symbolic) of the error, the two-way that must use grating sensor is phasic the output signal that needs 90 ° . Two sine that the phasic difference that the S in the graph and C output namely is 90 ° and cosine signal, make some way when bone feet when shift, π of C lead S / 2, the tall n of the pulse that S signal produces via differentiating circuit and C signal is in with the door 1 in get along with and obtain pulse output; And the low n of the believes date place arises instead pulse of S and C signal is in with the door 2 get along with, output low n. Manage together, when slide makes retrorse shift, π of S lead C / 2, with the door 2 output pulse, with the door 1 output low n, with the door 1 or with the door the pulse signal of 2 output controls tally respectively add decrease computation pulse, the output position of tally can mirror grating correctly deputy namely oil cylinder direction of shift of two pistons lever. Absolutely circuit of 0 potential function: The system runs a course actually in, appear interrupt move, stopping machine, power cut to wait is inevitable, this will bring about missing or wrong measurement result. When most grating is designed, place favour all is installed null labels, called at 0 o'clock with be being offerred in the job solved afore-mentioned problems at 0 o'clock absolutely. For this, due and corresponding absolutely null circuit, also namely null pulse forms circuit. To get used to key light bar to differ times frequency asks and assure null pulse and computation pulse synchronism, the primitive null signal that cannot use grating to output directly regards null as pulse, and the square wave after must choosing times frequency appropriately and the square wave get along with after primitive null signature manages, serve as with the weaveform with times frequency identical width choose a condition, the computation pulse that takes out from this regards null pulse as signal. 4 computers are online detect the simultaneous error signal of grating sensor collect, sentence through enlarge plastics, fractionize to pulse signal becomes to enter tally after waiting for circuit 8253, control the register of data send out in logic and shift register, convey digital signal chip 8250 interface circuit, have communication through RS-232 bus line and computer, data of compositive computer simultaneous error is automatic testing system. Below computer programme controll, real time, accurate, detect automatically simultaneous error data is recorded, for data analytic processing is used. The basis uses requirement and test research, this systematic program has following basic functions: (1) shows on video screen synchronism runs data in real time; (2) total travel or beforehand buy journey detects synchronous moving data; (3) begs average error and error fluctuant limits; (Moving curve of synchronism of 4) record scale and make data file. This program uses VB5. 0 languages are written, use the Mscomm that sets only to accuse the serial data between an implementation appearance and computer to correspond, use function process and child data of exemple Cheng implementation is collected, of the program such as scale of synchronous moving curve, data processing call. Graph 3 it is order flow block diagram. Graph the opposite displacement of lever of piston of two oil cylinder mirrorred the imitating test that 5 synchronism of 3 run synchronous system performance, and install the scale on lever of piston of two oil cylinder and slide to serve as detecting element respectively, adopt afore-mentioned testing system, the data that shows in real time, ground of direct real time mirrorred the opposite displacement between two pistons lever, namely synchronous moving circumstance. So, detect with relative standard the displacement between two pistons lever accords with operating condition completely. The principle of imitating test job that synchronism runs is shown 4 times like the graph. Get on stage of imitating test of park of oil cylinder of experiment of two long distances, feel draft lever of piston of oil cylinder of operating mode to load and experiment to grow lever of piston of journey oil cylinder to be formed through joining the car binds " to carrying oil cylinder on the head " , join car contains the gyro wheel that takes bearing, the car rolls on slideway the edge falls in order to make sure lever of piston of to load oil cylinder and experiment grow lever of piston of journey oil cylinder to move point-blank in force of very small attrition. Of oil cylinder of experiment long distance outside load is to adjust the mouth of throttle to spend respectively, the load outside forming what certain back pressure generation differs, the laden difference with be caused certain comes the real work state that the model appears long distance oil cylinder. When long distance oil cylinder is differred because of load or other element causes different condition, install the grating displacement sensor on lever of a place of strategic importance of oil cylinder of two long distances to have signal output. Signal is collected via all of commutation circuit, computation, computer science department, show, the processing, data that print, moving curve scale, make data file and grant memory and wait for postposition analysis processing. The different situation data of process of whole imitate operating mode collects processing to wait to undertake below computer programme controll, what achieve moving status automatically is online detect. Graph 4 use afore-mentioned imitating test systems, undertake to synchronous system load lays imitating test differring, graph 5 it is the simultaneous error curve that to load pressure detects in real time for 15MPa, synchronous the biggest error is 0.
18mm, accord with design requirement, show synchronous system has better synchronous performance. Afore-mentioned imitating test systems, a powerful person that forms back pressure the mouth is spent convert electronic-controlled manner varies by some rule or press random change, those who produce change outside laden, the synchronism that can move load in order to undertake experiments, study the dynamic performance of synchronous system. Graph the test method of the long distance oil cylinder that the article offers 6 last words of 5 , replace traditional absolutely displacement successfully to measure, have marked characteristic: (1) replaces many Cheng sensor with grain Cheng sensor, practical strong, simple and easy and feasible, it solved the oil cylinder with particularly long distance (be like 2 meters of above) purchase reach the technical difficult problem that when installing many Cheng sensor, encounters; (2) economic benefits is obvious, grain Cheng sensor is charge of many Cheng sensor ten or fewer, and serve as detecting element with grating sensor, check simultaneous error with relative standard function of synchronism of the directest, intuitionistic report, and can save sensor of a grating. Adaptability is strong, yi Ke is used at the synchronous moving test of oil cylinder of many long distances; (The installation that 3) magnetism sucks a structure to be able to realize sensor conveniently, adjust, when systematic occurrence breakdown, protect action to the safety since sensor; (4) computer testing system has the advantage with perfect function of fast, processing, online monitoring provided the test research that is an error and spot synchronism performance effective tool. Current, the test of much to growing the journey oil cylinder considers to still belong to basic blank condition, this research is had catholicity and practical, produce wide applied perspective. CNC Milling