CN114839081A

CN114839081A - Electric servo dynamic and static double-shaft high-low temperature fatigue testing machine

Info

Publication number: CN114839081A
Application number: CN202210611946.6A
Authority: CN
Inventors: 文瑞华; 杨善雷
Original assignee: Jinan Wenteng Test Instrument Co ltd
Current assignee: Jinan Wenteng Test Instrument Co ltd
Priority date: 2022-05-30
Filing date: 2022-05-30
Publication date: 2022-08-02

Abstract

The invention relates to the field of rubber testing machines, in particular to an electric servo dynamic and static double-shaft high-low temperature fatigue testing machine, which comprises a hardware system and a software system, wherein the hardware system comprises a rack, a high-temperature test box and a mounting rack are fixedly arranged at the top of the rack, servo electric cylinders are arranged on four sides of the high-temperature test box and are symmetrically arranged in a cross shape, the measuring precision of the invention is high, the technology is mature, the function is complete, the hardware system is used for collecting the surface image of a test piece and storing the surface image into a computer according to the time sequence, and finally the software system is used for calculating the collected image to obtain the corresponding result, the quality of speckles on the surface of the test piece, the intensity and the stability of a light source can influence the strain measuring precision, in addition, the computer also has the monitoring and safety protection functions, and the running states of all parts are monitored in real time in the testing process, the automatic stop or manual emergency stop can be realized under dangerous conditions such as stroke overload and the like.

Description

Electric servo dynamic and static double-shaft high-low temperature fatigue testing machine

Technical Field

The invention relates to the field of rubber testing machines, in particular to an electric servo dynamic and static double-shaft high-low temperature fatigue testing machine.

Background

As a super elastic material, rubber has been widely used in various industrial productions. In order to research the mechanical property of the material and design a rubber product meeting the requirement, various basic mechanical tests need to be carried out on the rubber, wherein a uniaxial test is the most common method for obtaining the mechanical property of the material, and a stress-strain relation curve of the material in the deformation process can be obtained through the tests.

There are relevant test standards for each different material. In the case of rubber, since the error of uniaxial compression test is large, the mechanical properties of the rubber are usually investigated by uniaxial tensile test. However, most rubber material products often experience biaxial loading during use, and therefore the mechanical behavior cannot be accurately characterized by only relying on uniaxial tensile data. Therefore, the mechanical property test of the rubber material under the action of the biaxial tensile load is more and more emphasized by researchers, so the demand of a device capable of carrying out the biaxial tensile test is more and more strong, in addition, the mechanical response of the rubber material under different combined stress states can be researched through the biaxial tensile test, and the research and the development of the rubber constitutive model are very helpful.

Furthermore, the integrity of the test data and the development of constitutive models can also promote the reliability and accuracy of numerical simulation of rubber under complex deformation conditions, and the biaxial tension test is carried out according to the properties of various tested materials and the force or displacement load required to be applied. Therefore, most biaxial tensile testing machines are designed and developed based on specific material mechanical properties. With the continuous development of testing machine technology, researchers at home and abroad design and develop various different types of biaxial tensile testing machines, most of which are suitable for metal materials, Japan and Germany have already finished establishing biaxial tensile testing standards for metal plates, and for rubber materials, no standardized testing instrument, testing method and test piece shape exist so far.

Therefore, a biaxial tensile testing machine suitable for rubber materials is designed and developed, and the machine is applied to research of mechanical tests of the rubber materials.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an electric servo dynamic and static double-shaft high-low temperature fatigue testing machine.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: an electric servo dynamic and static double-shaft high-low temperature fatigue testing machine comprises a hardware system and a software system, wherein the hardware system comprises a frame, the top of the frame is fixedly provided with a high-temperature test box and a mounting frame, the edge of the bottom edge of the frame is provided with an adjusting rubber mat, four sides of the high-temperature test box are provided with servo electric cylinders which are symmetrically arranged in a cross shape, piston rods of the servo electric cylinders are inserted into the high-temperature test box through holes, the top of the high-temperature test box is provided with an opening, the area of the opening is a half area of the top of the high-temperature test box, electric cylinder supports are arranged on the four sides of the top of the frame and correspond to the servo electric cylinders, the servo electric cylinders are supported by the electric cylinder supports, displacement sensors are arranged on the servo electric cylinders, the mounting frame is fixed on the top of the frame through two supports and is positioned on two sides of the high-temperature test box, the device comprises two supports, a top frame is welded between the tops of the two supports, a camera support is installed on the top frame, a CCD camera is installed on the camera support and is installed right above the center of the top of a high-temperature test box, a clamp is arranged in the high-temperature test box and is connected with a servo electric cylinder through a connecting shaft rod, a force sensor is arranged between the clamp and the servo electric rod, a software system is installed in a rack, a data transfer port is arranged on the rack and is electrically connected with the software system, the software system comprises a computer and a PLC controller, the PLC controller is electrically connected with the computer, the PLC controller comprises a servo driver and an encoder, the servo electric cylinder is connected with the PLC controller through a magnetic induction switch, the computer comprises a four-channel data collector and a four-channel instrument, and two force sensors in the high-temperature test box are connected with the computer through the four-channel instrument, the other two force sensors are connected with a computer through an amplifier and a four-channel data collector, the CCD camera is electrically connected with the computer, and a starting button and an emergency stop button are arranged on the rack and electrically connected with the computer.

Furthermore, the improved structure of the LED lamp comprises two groups of LED lamp brackets arranged between two supports of the mounting rack, the supports are of U-shaped structures, the LED lamp brackets are positioned on the front side of the opening, and the LED lamps are mounted on the LED lamp brackets and hinged with the LED lamp brackets.

Further, the improved fixture comprises a base, the base is of a U-shaped structure, a handle mounting plate is arranged at the top of the opening end of the base, the handle mounting plate is assembled with the base through an inner hexagon screw, a spiral handle is arranged on the handle mounting plate, a lower clamping block is arranged at the lower end of the opening through a sliding groove, the spiral handle penetrates through the handle mounting plate and the base and is connected with the base through threads, a connecting block is arranged at the end part of the spiral handle, and an upper clamping block is arranged on the connecting block through the sliding groove.

Furthermore, the invention is improved in that a lifting motor is arranged at the center position in the high-temperature test box, a lifting rod is arranged on the lifting motor, a placing platform is arranged at the top of the lifting rod, and a positioning groove is arranged on the placing platform.

Furthermore, the invention is improved in that the rack is made of industrial aluminum and is of a rectangular structure, and the size of each surface of the rack is 80mm multiplied by 80 mm.

In a further improvement of the invention, the internal working environment of the high-temperature test chamber is 750mm multiplied by 550mm, and the clamp adopts 45 steel.

The invention further improves the method, the displacement stroke of the clamp is 250mm, the displacement test speed range is 0.01 mm/min-500 mm/min, the displacement resolution of the servo electric cylinder is at least 0.001mm, the displacement indication precision is not lower than 0.005mm, the force value resolution of the force sensor is not lower than 0.01N, and the force value measurement precision is not lower than 0.5%.

Further, the invention improves that the highest experiment temperature of the high-temperature test box is 200 ℃, and the temperature deviation precision is +/-5 ℃.

(III) advantageous effects

Compared with the prior art, the invention provides an electric servo dynamic and static double-shaft high-low temperature fatigue testing machine which has the following beneficial effects:

the invention has the advantages of high measurement precision, mature technology and complete functions, collects the images of the surface of the test piece through a hardware system, stores the images into a computer according to time sequence, and finally calculates the collected images through a software system to obtain corresponding results, the quality of speckles on the surface of the test piece, the intensity and the stability of a light source influence the strain measurement precision, in addition, the computer also has the functions of monitoring and safety protection, monitors the running state of each component in real time in the test process, and can automatically stop or manually stop in emergency under dangerous conditions such as travel overload and the like.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of a fixture according to the present invention;

FIG. 3 is a loading schematic of the present invention;

in the figure: 1. a frame; 2. a high temperature test chamber; 3. a support; 4. a top frame; 5. a camera head bracket; 6. a camera; 7. an LED lamp holder; 8. an LED lamp; 9. a servo electric cylinder; 10. an electric cylinder bracket; 11. starting; 12. a start button; 13. an emergency stop button; 14. adjusting the rubber mat; 15. a base; 16. a handle mounting plate; 17. connecting blocks; 18. an upper clamping block; 19. a lower clamping block; 20. a screw handle; 21. a force sensor; 22. a coupling rod; 23. a clamp;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-3, the electric servo dynamic-static dual-axis high-low temperature fatigue testing machine comprises a hardware system and a software system, wherein the hardware system comprises a frame 1, a high-temperature test box 2 and a mounting rack are fixedly mounted at the top of the frame 1, an adjusting rubber mat 14 is arranged at the edge of the bottom edge of the frame 1, servo electric cylinders 9 are mounted on four sides of the high-temperature test box 2 and symmetrically arranged in a cross shape, piston rods of the servo electric cylinders 9 are inserted into the high-temperature test box 2 through holes, an opening is formed in the top of the high-temperature test box 2, the area of the opening is a half area of the top of the high-temperature test box 2, electric cylinder supports 10 are mounted on four sides of the top of the frame 1 and correspond to the servo electric cylinders 9, the servo electric cylinders 9 are supported by the electric cylinder supports 10, displacement sensors are arranged on the servo electric cylinders 9, the mounting frame is fixed on the top of the frame 1 through two supports 3 and located on two sides of the high-temperature test box 2, an upper frame 4 is welded between the tops of the two supports 3, a camera support 5 is mounted on the upper frame 4, a CCD camera 6 is mounted on the camera support 5, the CCD camera 6 is mounted right above the center of the top of the high-temperature test box, a clamp 23 is arranged in the high-temperature test box 2, the clamp 23 is connected with the servo electric cylinder 9 through a connecting shaft rod 22, a force sensor 21 is arranged between the clamp 23 and the servo electric rod, the software system is mounted in the frame 1, a data transfer port is arranged on the frame 1 and electrically connected with the software system, the software system comprises a computer and a PLC controller, the PLC controller is electrically connected with the computer, and comprises a servo driver and an encoder, servo electric cylinder 9 is connected with the PLC controller through the magnetic induction switch, the computer includes four-channel data collection station and four-channel instrument, 2 inside wherein two force sensor 21 of high temperature test case are connected with the computer through four-channel instrument, and two other force sensor 21 pass through amplifier and four-channel data collection station and are connected with the computer, CCD camera 6 and computer electric connection, be provided with 11 buttons of start and emergency stop button 13 in the frame 1, and with computer electric connection.

The electric servo dynamic-static double-shaft high-low temperature fatigue testing machine is characterized in that in order to facilitate the assembly of the testing machine and increase the testing space, the testing machine is horizontally arranged, the integrated rubber double-shaft tensile testing machine is debugged before testing, firstly, the stroke, the loading speed and the displacement resolution of each servo electric cylinder 9 are tested, then, the acquisition and reading of voltage signals of 4 force sensors 21 are tested, finally, the zero position of each clamp 23 is adjusted according to the shape of a designed test piece, the 4 clamps 23 are symmetrically arranged and are 50mm apart, the method is that the extending limit position of a piston rod of the electric cylinder is controlled by continuously adjusting the position of a magnetic induction switch on the electric cylinder, finally, the electric cylinder is coincided with the zero position of the clamp 23, the clamp 23 can return to the zero position through a manual or reset button, and then, the test piece is sprayed or marked with a background, then the tail end of each arm of the test piece is respectively clamped by four same clamps 23, parameters such as stretching displacement and stretching speed in all directions are set in a PLC (programmable logic controller), the servo electric cylinder 9 is controlled by a magnetic induction switch to drive a connecting shaft rod 22 to displace the clamps 23 so as to realize loading of the four arms, in order to ensure the quality of image acquisition, an LED lamp 8 light source is also arranged, during the test, data such as force, displacement, strain and the like in the test process are acquired in real time through a force sensor 21, a displacement sensor and a CCD (charge coupled device) camera 6, meanwhile, synchronous acquisition of force and strain data is required to be ensured, the absolute range of strain measurement is 10mm multiplied by 10 mm-40 mm multiplied by 40mm, the absolute precision of strain measurement is not lower than 100 mu epsilon, the four servo electric cylinders are of the same type, the PLC is a programmable logic controller and is easy to be connected with the servo electric cylinder 9, and can realize high-precision servo motion control, the device is connected with external device image processing software through a data transfer interface, and is used for checking and analyzing experimental data in real time.

At present, most rubber biaxial tension tests adopt an edge detection method or a digital image correlation method (DIC method) to carry out strain measurement, wherein the DIC method not only has higher measurement precision, but also can obtain displacement and strain data of each point in a full-view range, and is more favorable for analyzing and researching the deformation of a rubber material in a biaxial tension state. Therefore, the testing machine selects the VIC-2D full-field strain measurement system, the measurement precision of the system is high, the technology is mature, the function is complete, and the system is widely applied to various industries and scientific research fields, the VIC-2D full-field strain measurement system collects images on the surface of a test piece through a hardware system, stores the images into a computer according to time sequence, and finally calculates the collected images through a software system to obtain corresponding results, the quality of speckles on the surface of the test piece, and the intensity and stability of a light source can influence the strain measurement precision.

Four connecting rods 22 of the biaxial tensile testing machine are respectively 0-3 defined according to the anticlockwise direction, as shown in figure 3, because a VIC-2D full-field strain measurement system is independent of a control system and can not be communicated with each other, and a tensile curve requires that stress and strain data need to be synchronously collected, force sensors 21 on two

shafts

0 and 1 in different directions are connected with a four-channel analog data collector, voltage analog signals of the force sensors can be read in real time through VIC-SNAP software on a computer, synchronous collection of the voltage signals and speckle images can be realized, the voltage signals and the speckle images are output to a CSV file of the computer to be stored, namely, the one-to-one corresponding relation of the force and the strain data is realized, meanwhile, the other two force sensors 212 and 3 are communicated with the computer through a four-channel standard instrument to realize force control, and because the force sensors 21 on the shaft 0 and the shaft 1 are lack of feedback control, the two shafts will move according to the

shafts

2 and 3 in the same direction respectively to ensure the two shafts move in the same direction.

In order to increase the accuracy of 6 image acquisition of CCD camera, in this embodiment, be equipped with two sets of LED lighting fixture 7 between two supports 3 of mounting bracket, support 3 is the U-shaped structure, just LED lighting fixture 7 is located the open-ended front side, install LED lamp 8 on the LED lighting fixture 7, LED lamp 8 is articulated with LED lighting fixture 7, because the space light source in the high temperature test case 2 is not enough, shines the test piece through LED lamp 8 in the experiment to the test piece, and 6 image acquisition in-process can get into more light sources again of CCD camera to make image information collection more comprehensive, it is more accurate, LED lamp 8 can adjust the angle of shining in a flexible way through articulating with LED lighting fixture 7, adjust the position of shining.

In order to improve the convenience that anchor clamps 23 used, anchor clamps 23 include base 15, base 15 is U type structure, the open end top of base 15 is provided with handle mounting panel 16, handle mounting panel 16 passes through hexagon socket head cap screw and the equipment of base 15, be equipped with spiral handle 20 on the handle mounting panel 16, open-ended lower extreme is installed through the spout and is pressed from both sides tight piece 19 down, spiral handle 20 runs through handle mounting panel 16 and base 15 to through threaded connection, spiral handle 20's tip is equipped with connecting block 17, connecting block 17 installs through the spout and presss from both sides tight piece 18, and anchor clamps 23 adjust through rotating spiral handle 20 when using and press from both sides tight piece 18 and press from both sides the interval between the tight piece 19 down to clamp again after putting into anchor clamps 23 with the test piece.

In order to guarantee the position accuracy of the test piece on the testing machine, in the embodiment, the central position inside the high-temperature test box 2 is provided with the lifting motor, the lifting motor is provided with the lifting rod, the top of the lifting rod is provided with the placing platform, and the placing platform is provided with the positioning groove.

In this embodiment, the frame 1 is made of an industrial aluminum material, the frame 1 has a rectangular structure, and each surface of the frame 1 has a size of 80mm × 80 mm.

In this embodiment, the internal working environment of the high-temperature test chamber 2 is 750mm × 750mm × 550mm, and the clamp 23 is made of 45 # steel.

In the embodiment, the displacement stroke of the clamp 23 is 250mm, the displacement test speed range is 0.01 mm/min-500 mm/min, the displacement resolution of the servo electric cylinder 9 is at least 0.001mm, the displacement indication precision is not lower than 0.005mm, the force value resolution of the force sensor 21 is not lower than 0.01N, and the force value measurement precision is not lower than 0.5%.

The highest experimental temperature of the high-temperature test box 2 is 200 ℃, and the temperature deviation precision is +/-5 ℃.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The electric servo dynamic-static double-shaft high-low temperature fatigue testing machine is characterized by comprising a hardware system and a software system, wherein the hardware system comprises a rack (1), a high-temperature test box (2) and a mounting rack are fixedly mounted at the top of the rack (1), an adjusting rubber mat (14) is arranged at the edge of the bottom edge of the rack (1), servo electric cylinders (9) are mounted on four sides of the high-temperature test box (2) and are symmetrically arranged in a cross shape, piston rods of the servo electric cylinders (9) are inserted into the high-temperature test box (2) through holes, an opening is formed in the top of the high-temperature test box (2), the area of the opening is a half area of the top of the high-temperature test box (2), electric cylinder supports (10) are mounted on four sides of the top of the rack (1) and correspond to the servo electric cylinders (9), and the servo electric cylinders (9) are supported by the electric cylinder supports (10), the device is characterized in that a displacement sensor is arranged on the servo electric cylinder (9), the mounting frame is fixed to the top of the frame (1) through two supports (3) and located on two sides of the high-temperature test box (2), an upper frame (4) is welded between the tops of the two supports (3), a camera support (5) is installed on the upper frame (4), a CCD camera (6) is installed on the camera support (5), the CCD camera (6) is installed right above the center of the top of the high-temperature test box, a clamp (23) is arranged in the high-temperature test box (2), the clamp (23) is connected with the servo electric cylinder (9) through a connecting shaft rod (22), a force sensor (21) is arranged between the clamp (23) and the servo electric rod, the software system is installed in the frame (1), and a data transfer port and the software system are arranged on the frame (1) and electrically connected with the software system, software system includes computer and PLC controller, PLC controller and computer electric connection, the PLC controller includes servo driver and encoder, servo electronic jar (9) are connected with the PLC controller through the magnetic induction switch, the computer includes four-channel data collection station and four-channel instrument, wherein two force sensor (21) inside high temperature test case (2) are connected with the computer through four-channel instrument, and two other force sensor (21) are connected with the computer through amplifier and four-channel data collection station, CCD camera (6) and computer electric connection, be provided with start (11) button and emergency stop button (13) on frame (1), and with computer electric connection.

2. The electric servo dynamic-static dual-axis high-low temperature fatigue testing machine is characterized in that two sets of LED lamp brackets (7) are arranged between two supports (3) of the mounting frame, the supports (3) are of U-shaped structures, the LED lamp brackets (7) are located on the front side of an opening, LED lamps (8) are mounted on the LED lamp brackets (7), and the LED lamps (8) are hinged to the LED lamp brackets (7).

3. The electric servo dynamic-static double-shaft high-low temperature fatigue testing machine is characterized in that the clamp (23) comprises a base (15), the base (15) is of a U-shaped structure, a handle mounting plate (16) is arranged at the top of the open end of the base (15), the handle mounting plate (16) is assembled with the base (15) through an inner hexagonal screw, a spiral handle (20) is arranged on the handle mounting plate (16), a lower clamping block (19) is arranged at the lower end of the opening through a sliding groove, the spiral handle (20) penetrates through the handle mounting plate (16) and the base (15) and is connected through threads, a connecting block (17) is arranged at the end part of the spiral handle (20), and an upper clamping block (18) is arranged on the connecting block (17) through a sliding groove.

4. The electric servo dynamic-static double-shaft high-low temperature fatigue testing machine as claimed in claim 3, wherein a lifting motor is installed at a central position inside the high temperature test box (2), a lifting rod is installed on the lifting motor, a placing platform is arranged at the top of the lifting rod, and a positioning groove is arranged on the placing platform.

5. The electric servo dynamic-static biaxial high-low temperature fatigue testing machine as claimed in claim 4, characterized in that the frame (1) is made of industrial aluminum, the frame (1) is of a rectangular structure, and the size of each surface of the frame (1) is 80mm x 80 mm.

6. The electric servo dynamic-static biaxial high-low temperature fatigue testing machine as claimed in claim 5, characterized in that the internal working environment of the high temperature test box (2) is 750mm x 550mm, and the clamp (23) is made of No. 45 steel.

7. The electric servo dynamic-static double-shaft high-low temperature fatigue testing machine as claimed in claim 6, characterized in that the displacement stroke of the clamp (23) is 250mm, the displacement testing speed range is 0.01 mm/min-500 mm/min, the displacement resolution of the servo electric cylinder (9) is at least 0.001mm, the displacement indication precision is not lower than 0.005mm, the force value resolution of the force sensor (21) is not lower than 0.01N, and the force value measurement precision is not lower than 0.5%.

8. The electric servo dynamic-static biaxial high-low temperature fatigue testing machine as claimed in claim 7, wherein the highest experimental temperature of the high temperature test box (2) is 200 ℃ and the temperature deviation precision is ± 5 ℃.