Electro-hydraulic servo dynamic and static universal testing machine is widely used in dynamic and static mechanical properties test of materials and parts, including tensile, compression, low cycle and high cycle fatigue test of materials and parts.
1. Introduction:
Electro-hydraulic servo dynamic and static universal testing machine is widely used in dynamic and static mechanical properties test of materials and parts, including tensile, compression, low cycle and high cycle fatigue test of materials and parts. High and low temperature mechanical test can be carried out with high and low temperature chamber.
During the development and development process of electro-hydraulic servo dynamic and static universal testing machine series, it adopts the development experience of internationally famous electro-hydraulic servo dynamic testing machine company, adopts the development concept of "unization, modularization and standardization", absorbs the international advanced electro-hydraulic servo dynamic testing machine technology, and is designed according to the actual use situation of domestic users. The key supporting components of the electro-hydraulic servo dynamic testing machine are selected from famous brands of similar international and domestic products. The stability and reliability of the system are greatly improved, the key units and components of the system are manufactured with today's international advanced technology, and the overall performance of the whole test system is equivalent to the technical level of the internationally famous dynamic testing machine company. This series of products has the characteristics of easy to use, high control precision, good reliability and so on.
Embedded channel fatigue testing machine is one of the series of static and dynamic universal testing machine products developed by our company. Testing machine host, constant pressure servo pump station, hydraulic clamp and other key components are designed and manufactured for our company, servo valves, seals and other key purchased parts are selected international and domestic similar products of famous brand products, greatly improve the stability and reliability of the system, the overall performance of the testing machine and the international advanced product technology level. It meets the requirements of TBT/T3329-2013, X1-J1-2017, TBT/T2074-2010 and other relevant standards.
2. Program description:
The 50kN electro-hydraulic servo dynamic and static universal testing machine is mainly composed of a main machine (50kN servo linear actuator), hydraulic chuck and its hydraulic drive module, a set of constant pressure servo pump station (flow rate 36L/min, system pressure 21MPa), full digital single-channel servo controller and computer printer, related test software, other necessary accessories.
See FIG. 1 and 2 for the working principle diagram and control block diagram.
Figure 1 System working principle diagram
Figure 2 System control block diagram
Figure 3: Photo of the host computer (subject to the actual object)
1, the main machine: the main machine is a double column frame structure, 50kN servo linear actuator is placed inside the main machine frame. The forced hydraulic chuck is mounted on the top of the beam and the actuator rod respectively. The host beam adjustment adopts hydraulic lifting, hydraulic clamping, elastic release structure, to ensure that the beam is stable and reliable during the test, and to ensure that the beam remains locked in the non-test state. The outer surface of the column is treated with hard chromium plating, which can effectively increase the anti-wear ability of the column, improve the anti-corrosion ability, and increase the beauty of the main body.
The main machine of the testing machine has the characteristics of compact structure, easy lifting of the beam, high stiffness of the frame, reliable clamping of the specimen, good neutrality, convenient clamping, etc., and can be equipped with various fixtures and environmental test devices to expand the test function.
1.1, the main machine is a four-column frame structure, the outer surface of the four columns adopts hard chromium plating to further improve the appearance of the aesthetic degree, while improving the anti-corrosion ability;
1.2, the beam can be lifted to adjust the test space, the beam adjustment adopts hydraulic lifting, hydraulic clamping, elastic release structure, to ensure that the test is stable and reliable, and ensure that the beam remains locked in the non-test state;
1.3. The beam movement (lifting and locking) is controlled by the beam drive module, two clamping cylinders and two lifting cylinders are coordinated to complete the work, and the drive module is controlled by a special manual rotary valve with zero leakage, which can ensure the reliability of the test;
1.4, the load sensor is installed on the bottom end of the beam for measuring the test load.
1.5. The sample clamping, beam movement and emergency stop operation buttons are designed in front of the main machine workbench to facilitate the easy operation of the tester.
2. Actuator:
The servo linear actuator is the core component of the testing machine, and the testing machine outputs the test force through the actuator. The actuator is built in the lower part of the main engine and is composed of the actuator body, hydraulic control module and sensor.
2.1. The actuator uses a servo linear actuator and adopts a symmetrical four-way servo valve control pair called the actuator principle. The actuator is designed and manufactured with the concept of unit, modularization and standardization, and adopts multi-stage flexible support combination guide mechanism, which has the characteristics of low damping, high response, high life and large gap design. Zero starting pressure, no crawling.
2.2, the actuator piston seal adopts the gap seal mode, adopts the imported sealing ring support, large gap design, high resistance to side force, and has the characteristics of high-speed non-sintering self-lubrication. Combined seal, high pressure seal, low pressure seal and gap leakage pipe, actuator assembly to make no leakage oil. The above sealing method can effectively reduce the internal friction resistance of the actuator, improve the test accuracy of the testing machine and the service life of the actuator. Servo linear actuator frequency response is not less than 100Hz.
2.3, servo linear actuator amplitude limit position design hydraulic buffer to avoid running out of control damage.
2.4, the servo linear actuator displacement sensor movement is flexible without external interference, the piston rod adopts super finishing, the surface plating and polishing up to Rα0.4u.
2.5. The actuator is equipped with a hydraulic module composed of a precision oil filter with a filtration accuracy of 0.003mm, an inlet and return oil circuit accumulator with pulse elimination and energy storage functions, and a two-stage electro-hydraulic servo valve for the dynamic testing machine of MOOG Company in the United States. The precision oil filter is installed in front of the electro-hydraulic servo valve, which can effectively prevent the electro-hydraulic servo valve from clogging due to hydraulic oil pollution.
2.6, load sensor and hydraulic chuck screw, piston rod and hydraulic chuck designed a special clearance device to further improve the dynamic response performance.
3, constant pressure servo pump station:
The pumping station is mainly composed of baseplate, oil tank, oil pump electric unit, valve block, pipeline, cooling system and so on. It is used to provide the power of the testing machine.
3.1, the pump station tank adopts a fully enclosed design, which can effectively prevent external impurities from entering the hydraulic system to pollute the hydraulic oil. The oil tank is made of stainless steel plate, which can effectively prevent metal corrosion from polluting the hydraulic oil.
3.2. The oil pump and electric unit are configured with double elastic support in series to further reduce the noise of the pumping station.
3.3, the oil pump adopts low noise linear conjugate internal gear pump. Features: In the hydraulic industry is known as "never wear oil pump", used for high, fine, sharp hydraulic system. Several famous companies in the world have developed and promoted it as a brand product to ensure its leading position in the hydraulic industry. Compared with vane pump and plunger pump, linear common internal gear pump has excellent performance such as low noise, no pulsation and long life. Low noise: The excellent feature of the linear common frontal internal gear pump is a special gear design, the gear tooth gallery is a straight line, the gear ring tooth profile is a straight common line, and there is almost no trapped oil area when working, even at high speed, the audio is still smooth and peaceful. Long life: the long life characteristics of the linear internal meshing gear pump depend on the wear resistance, the internal mechanical surface and the functional parts have a layer of oil film protective layer, almost no wear, even if the use of general hydraulic oil, it is not easy to wear parts. In addition, the principle of two-stage pressure bearing pressure difference increases the working pressure, but also improves the working conditions of the pump and prolongs the service life of the pump;
3.4, by the main relief valve, accumulator, auxiliary main relief valve, auxiliary relief valve and reversing valve, precision oil filter composed of high and low pressure soft switching hydraulic module used to control the output pressure of the pump station;
3.5, the pump station has a low pressure start, high pressure switching mode, can effectively reduce the impact of the hydraulic system;
3.6, the pump station is equipped with in-line water cooler (cooling water user) for hydraulic system cooling;
3.7, the pump station is equipped with double electric contact temperature control meter, liquid level control meter; Features oil temperature (below 10ºC, above 55ºC), liquid level, oil filter clogging alarm and parking protection
3.8, the pump station is equipped with hydraulic pipe fittings and high pressure hose to ensure that the system has no leakage;
Attached: Photo of constant pressure servo pump station
4, full digital single channel servo controller:
5.1 The control system adopts our company's full digital hydraulic servo controller. Main configuration:
Dsp-based core control module that supports multi-channel closed loop;
Signal conditioning unit with three sensors (force, displacement, deformation)
Secondary servo valve drive unit
Test control software system test software intuitive, readable;
4.2 SuptestV4.2 Main Technical specifications
Control module: can achieve closed-loop control function, can arbitrarily collect signals for full digital closed-loop control, closed-loop control frequency of 10kHz;
Servo valve drive unit: drive control of nozzle servo valve;
Waveform generator frequency range: 0.001-50Hz, frequency resolution: 0.001Hz;
Control waveform: sine wave, triangle wave, square wave, sawtooth wave, half sine wave, half triangle wave, random wave and external input waveform;
Control mode: Closed loop control of force, displacement and deformation, which can realize smooth switching of any control mode;
The system has sensor calibration and zero clearing functions;
Perfect hydraulic station monitoring function, can monitor oil temperature, pressure, etc.
4.3 Computers and printers
Brand computer, mainstream configuration
HP printer
Three, the main technical performance indicators:
1, the maximum static test force: ±50kN
Maximum dynamic test force; ±40kN
2, test force measurement range: 1 ~ 100% (the whole process is not graded); Measurement accuracy: ±1% F.S
3. Test space:
3.1 Maximum adjustable test net space: 800mm
3.2 Effective column spacing: 600mm
4, actuator travel range: 0-150mm
5. Accuracy of testing machine:
5.1 Force and deformation measurement accuracy: ±0.5% (static) better than the indicated value (static) than ±1.0% (dynamic)
5.2 Displacement measurement accuracy: better than the indicated value ±0.5% (static) Better than the indicated value ±0.5% (static)
5.3 Average load fluctuation of test force: ±1%;
5.4 Dynamic load fluctuation of test force: ±1%;
6, test waveform: rectangular wave, triangular wave, square wave, sine wave, sawtooth wave, and user-defined waveform.
7, test frequency: 0.01 ~ 25Hz (3Hz amplitude is (0.7 ~ 1.3) times the working load)
8, fatigue times: 1×107 times (optional)
9, control mode: force, displacement, deformation PID closed-loop control, and can achieve any control mode smooth undisturbed switching.
10, configuration of hydraulic pump station: flow 36L/min, pressure 21Mpa.
11, configure a set of operating computer and print out equipment.
12, test software: suitable for Windows test platform operation. In combination with the control system, the test system can be controlled to complete various dynamic and static mechanical properties tests, and different test tools can be installed to achieve the test requirements of anchors, T-bolts and embedded concrete in the embedded channel. The software not only controls the work of the test system, but also has the functions of drawing all kinds of test curves that meet the requirements of static test, test management, data storage and test report printing.
