Force gauge, tensile machine, vulcanizer
We usually see the actual test machine should be called the material testing machine, it is a kind of test used to measure a variety of mechanical and physical properties of the material type parts of the instrument.
Overview of the test machine
1. Definition
1.1 test machine concept and use of the test machine is in a variety of conditions, the environment to determine the metal materials, non-metallic materials, mechanical parts, engineering structures, etc., mechanical properties, process performance, internal defects, and calibration of rotating parts of the dynamic unevenness of the precision testing equipment.
1.2 types of testing machines: many types of testing machines, there are a variety of different classification methods. According to the traditional classification method can be divided into metal materials testing machine, non-metallic materials testing machine, force gauge, tensile strength machine, vulcanization instrument
test machine, vibration table and non-destructive testing machine and other five categories. 1.2.1 Classification of materials testing machine:
1.2.1.1 According to the use of classification: the determination of mechanical properties with the testing machine and process testing machine
1.2.1.2 According to the loading method classification: static load testing machine (static) and dynamic load testing machine (dynamic)
1.2.1.2.1 static testing machine include: force gauge, tensile, vulcanization instrument
1.2.1.2.1 Static testing machine include: Force, pulling, vulcanization instrument
1.2.1.2.2 dynamic testing machine mainly includes: fatigue testing machine: static and dynamic universal testing machine, impact testing machine, etc.
1.2.1.3 according to the classification of the force measurement mode: mechanical force testing machine and electronic force testing machine
1.2.1.4 according to the classification of the control mode: manual control and microcomputer servo control of the testing machine
1.2.1.5 according to the classification of the force testing machine and the electronic test machine
1.2.2.1.5 according to the classification of the force testing machine
1.3 material testing
1.3.1 mechanical properties of the material
1.3.2. material testing: mechanical properties of the test, physical experiments, chemical experiments.
1.3.3 mechanical properties of materials test:
1.3.3.1 force gauge, tensile machine, vulcanization instrument
Also known as the force gauge, tensile machine, vulcanization instrument There are many ways to classify the materials testing machine, the common ones are:
a) in accordance with the type of the source of the force is divided into the main motor, hydraulic, pneumatic, electromagnetic and so on several kinds;
b) According to the measurement of the end of the type of indication, there are mainly digital, pointer;
c) according to the specimen is subjected to the relationship between the load and time are: static too machine and fatigue machine.
d) According to the control mode, there are mainly open-loop control (manual control) and closed-loop control (automatic control)
For closed-loop control, such as Jue's control type are: speed control, load control, deformation control, position control.
e) according to the use of the main general-purpose machine force gauge, tensile strength machine, vulcanization instrument
specialized machine.
There are many types of special machines, such as: cement force gauge, tensile strength machine, vulcanization instrument
, red brick press, wire bending fatigue machine, soft worry machine, electric porcelain bending and twisting machine, horizontal pull and so on, far from the balancing machine, far from three-axis, shaking table.
f) test methods and testing machines
Generally speaking, there are only two kinds of testing machines: the direction of movement (or direction of force), a kind of pull, a kind of pressure, we usually see pulling, pressing, bending, shearing, peeling, tearing, wearing, wearing, and so on, this kind of specimen for. Open-loop control
Closed-loop control
Fifth, detection and control of staging
Detection of staging: can be divided to improve the sensitivity of the measurement, to solve the problem of the large management station weighing small things.
Control gearing: used to solve the problem of precise "positioning", but also to solve the problem of measurement accuracy
Sixth, gear amplification and the range of the relationship between gearing
These are two different concepts, but they are related to each other.
Grade amplification is a force gauge, tensile strength machine, vulcanization instrument
Amplifier of a local parameter, while the range of grades refers to a pair of characteristic parameters of the test machine
The latter has a practical meaning for the user, while the former does not require the user to pay attention to.
Seven, D / A, A/D converter
D / A ---- digital volume converted volume
A / D ---- analog black heart digital volume
Digital volume for example: a cup of soybeans, you can heart how many beans with how many to count out how much it is, but the number is always 1, 2, 3, 4, ... ...n
On the concept of "code": original code, inverse code, complement code, ASCII Gray Code.
The concept of "number system": decimal, binary, hexadecimal, BCD code.
Sensor: A device that converts various measurements into electrical signals.
1, common sensors: load sensing, deformation gauge, displacement sensors, pressure sensors, temperature sensors (thermocouples, RTDs, semiconductor temperature sensors) differential pressure sensors, gilt sensors.
2, piezoelectric crystal load sensor, grating, magnetic grating, force gauge, tensile strength machine, vulcanization meter
(incremental, absolute) and so on.
Analog sensors in front operation, digital sensors in back operation.
According to the measurement of the material is divided into: metal testing machine, non-metallic testing machine
According to the function is divided into: force gauge, tensile strength machine, vulcanization instrument
, universal testing machine, impact testing machine, etc. Due to the specificity of the structure of the fixture, a fixture, sometimes it is difficult for us to determine what kind of specimen is more suitable for it in the end, usually from the following three points to determine:
1, Whether the fixture is easy to use, safe.
2, whether the clamping is reliable, there can not be slippage.
3, do the test process, the specimen breakpoint is good. Data dispersion is small. (i.e., the specimen is not constantly jaws, jaws, parallel segments or outside the mark)
And there are several types of materials, there are special with their own characteristics and the applicable environment, so far, the solution is not much
1, steel wire, stranded steel wire due to the high hardness of the specimen, the internal structure of the relative looseness of the tensile test process is not uniform force, clamping specimen jaws easy to wear and so on, the fixture Has not been a good solution. In the past, it was to clamp aluminum foil to do, a test consumes four pieces of aluminum foil, too much waste. The use of diamond spraying tensile testing machine fixture, slipping problem solved, but the fracture position has never been ideal, 10 specimens can only be about half of the success.
2, for the deformation of the material due to the deformation of the material is too large, so it is difficult to clamp, the design of the fixture is also a difficult point.
3, for the need to do the test in a high-temperature environment, vortex flowmeter fixture requirements are also very high, both high temperature resistance, but also to not deform, the volume should be small, so the general test machine manufacturers, but also very difficult to deal with the matter.
4, for large batch, high-frequency test, foreign countries generally use fully automatic clamping, and domestic manufacturers of testing machines, or a new subject
5, and finished products and semi-finished products, the need for a variety of fixtures, how to personalize to meet customer requirements, for all manufacturers of testing machines, is a challenge.
System configuration
1. Testing machine host
(a) all-digital servo control drive
all-digital servo control motor
(b) high-precision Sequan sensor 10kN
(c) high-precision screw sub
(c) photoelectric displacement sensor
(d) synchronous belt Deceleration system
2. Finetest microcomputer control controller
3. Finetest testing machine control software
4. Standard tensile attachments
Standard compression attachments
5. Brand-name computers (optional)
2. Mainframe table: force measuring instrument, tensile force machine, sulfurization instrument
. According to different levels of customer demand is mainly divided into the following three kinds:
Microcomputer control single-arm electronic tensile tester digital electronic tensile tester microcomputer control door electronic tensile tester
So, what kind of rubber tensile tester we should choose a rubber tensile test?
One, first of all, should understand: in accordance with the relevant standards, we need the data is what? Generally speaking, the rubber tensile test need to find the following items or seven parameters
1. specimen stretching to break the maximum force (tensile strength);
2. specimen fracture force (breaking strength);
3. Yield point of the force corresponding to the value of the yield point (yield point tensile stress);
4. specimen stretched to the given elongation (fixed elongation stress) The value of force at which the specimen is stretched to a given elongation (constant stress);
5. The elongation of the specimen at which the specimen is stretched to a given stress (constant stress elongation);
6. The elongation corresponding to the point of yield (yield point elongation);
7. The elongation at which the specimen is fractured (tearing elongation).
II. According to the requirements of the above measured parameters. Rubber tensile test process needs to be tracked during the data there are two: tensile force value and the amount of change in scale distance.
So the rubber tensile testing machine used to test the rubber tensile properties of the rubber must meet the following four requirements:
1. Large stroke.
Because the rubber deformation in tension is very large, especially latex products, the elongation may be as high as 1000% or more. So before the rubber specimen breaks, it is necessary to ensure that the gripper has enough stroke.
2. High precision and high frequency data acquisition.
Stretching rubber does not require a lot of force, the tensile force measurement range does not need to be very large, so the need for high precision of the force value. The general requirements of the force gauge, tensile machine, vulcanization instrument
Can be obtained more than two decimal places accuracy of the force value. In addition, due to the detection of rubber tensile properties need to stretch the process of several tensile values, and tensile test is not repeatable, so immediate and accurate record of each test section of the tensile force value for the success or failure of the test plays a very important role.
3. Accurate distance measurement and recording device (as shown).
The measurement of specimen distance is an important data to calculate the elongation of rubber, so the rubber tensile test machine must accurately measure the strain of the specimen and instantly record it.
4. Device that can accurately describe the stress-strain curve.
There is a close relationship between the value of the tensile force in the tensile specimen and the scale, for example: the specimen's constant elongation stress needs to measure the specimen stretched to a given elongation of the force value, depending on the stress needs to measure the specimen stretched to a given stress scale. After the completion of the test, the accurate stress-strain curve can reproduce the test process, and clearly reflect the value of each test section, easy to calculate the test requirements of the project
Three, the tester rubber tensile testing machine selection reference
Comprehensive above, the tester according to the following methods to select a suitable rubber tensile testing machine
1. ...Testing machine Stroke range.
Ordinary standard thickness specimens (1, 2, 4-type dumbbell-shaped specimen thickness of 2.0 ± 0.2mm, 3-type specimen thickness of 1.0 ± 0.1mm) when the breakage of the mark is generally within 1 meter; special thickness specimens, such as medical rubber gloves specimen, the mark when the breakage of the mark may be more than 1 meter. So the fixture moving range is generally between 1 meter and 1.5 meters, which can be suitable for a variety of rubber specimen tensile test. To actually meet this requirement is not difficult, the general rubber tensile testing machine mechanical transmission part can meet.
2 rubber tensile testing machine tensile force measurement and recording device.
Tension testing machine tension measurement and recording device mainly consists of two kinds: mechanical instrumentation and sensor type. Mechanical instrumentation type tension measurement device mainly rely on the reaction force in the stretching process, through the spring, weights and other mechanical transmission devices driven by the instrument panel on the pointer rotation marking the tension value, and the use of traditional recorders to record the force value - time curve. Mechanical instrumented tensile testing machine is cheap, but its performance can not meet the requirements of the rubber tensile test, it can only deal with the tensile value alone, can not record the subtle changes in the tensile value, and will be the tensile value and the specimen distance effectively linked. Tensile testing machine equipped with appropriate accuracy of the tension sensor can accurately record the value of the tension at each moment, and through the relevant program for processing, calculating, in order to meet the requirements of the rubber tensile test.
3. Testing machine Scale distance measurement and recording device.
Rubber distance measurement is an important part of the tensile test, directly affecting the accuracy of the test. At this stage, there are two main methods of distance measurement: manual measurement and automatic measurement. Manual measurement is in the fixture to move the rod side of the vertical set up a ruler and two can be moved in the vertical direction of the horizontal distance bar, tensile test, by visual observation of the specimen on the distance of the changes in the distance, manual control of the two distance bar, so that it is synchronized with the distance on the specimen distance, and at the same time to record the distance bar in the distance bar in the ruler on the distance of the movement. The error of manual measurement is very large: first, visual observation of the specimen distance will cause a certain deviation; second, by manually moving the distance bar can never accurately track the specimen distance change; third, the test personnel while moving the distance bar, it is difficult to record the value of the distance bar, and can not accurately describe the stress-strain curve at the end of the test.
Compared with the automatic measurement of the distance is more conducive to the detection of rubber tensile properties. Many tensile testing machine automatic scale distance measurement device using contact sensors to instantly measure the changes in scale distance, the sensor mobile device is installed in two main positions: ① installed in the fixture; ② specimen. Will move the device installed in the clamp sensor has certain limitations. Due to the elastic deformation of rubber is very large, the gripper's moving distance and the specimen scale distance of the change in the value of a large gap, so installed in the fixture on the scale distance sensor is more suitable for detecting elastic deformation of the specimen is very small (eg, metal materials) tensile properties, but can not be used to detect the rubber tensile properties.
Another installation is in the fixture moving rod vertically set up a scale and two can be moved in the vertical direction, with a small clip of the horizontal range bar (commonly known as: large deformation). The installation of this sensor and the manual measurement described above is the same principle of use, just change the scale into a grating, the manual operation is changed to the specimen driven by the scale bar movement. Installed in the scale on the sensor is suitable for metal or standard thickness of rubber specimens tensile test, because the value of the force when stretching these specimens is large, the force value of the scale rod driven by the movement of the value of a very small compared to the specimen will have a certain impact, but not enough to affect the success or failure of the entire test.
But the rubber tensile performance testing of some special specimens can not take the contact sensor for distance measurement, such as medical rubber gloves specimen. Rubber gloves are mainly composed of natural latex, tensile test process used in the tensile value is smaller than the general rubber products, at the same time GB7543-1996 "rubber medical gloves" in the provisions of the tensile performance test specimen is directly in the rubber medical gloves on the finished product is cut directly, so cut down the thickness of the specimen is very small, about only 0.2mm, so that the thickness of the latex specimen only need to take contact sensor distance measurement. The thickness of the latex specimen is only about 0.2mm, so the latex specimen only needs a small force value to stretch the specimen for a long time. So take the contact distance measuring method on the specimen tensile test will have a great impact, the impact of the following reasons: First, contact with the specimen of the distance rod of the weight of the specimen will be pulled down the specimen, affecting the tensile force measurement; Second, the distance of the rod of the clamping of the clamped parts of the stretching of a certain impact, so that it can not be freely stretched.
The above problems can be avoided by adopting a non-contact video extensometer, and the use of a video camera to track the change of the marking distance is one of the methods. Specimen background with black rough non-reflective material (such as black rough insulation tape), the distance part (i.e., between the two distance line part) with high contrast paint color (if the specimen color is lighter than the distance with black paint, if the specimen color is darker than the distance with white paint), the camera captures the image into the computer, adjust the contrast, so that the distance boundary in the computer can be clearly discernible. In the stretching process through the computer to process the collected images, the mark distance line tracking, real-time test mark distance value. This measurement method not only can accurately measure the mark distance value at each moment, but also will not affect the rubber stretching process.
Test steps
1. Start the program;
2. Click on the pop-up welcome interface to make disappear, if the pop-up "serial port initialization success! then go to part 3, if the pop-up "serial port initialization failed!" Then click "Parameter Setting->Serial Port Selection->COM1" in the menu bar, if "Serial Port Initialization Failed!" pops up again, then enter the 3rd part. then click the menu bar in the "parameter settings - & gt; serial port selection - & gt; COM2", and so on, until the pop-up "serial port initialization success!
4. Click the "Parameter Settings-> Initial Value Setting" in the menu bar to set the initial value to the desired value;
5. Click the "Parameter Settings-> Test Material" in the menu bar to set the initial value to the desired value. Test Material" in the menu bar, and then select the edited material in the pop-up dialog box, or you can click "Modify" to modify the information of the currently selected material, or click "Add" to add a new material, and then enter the material to be tested in the pop-up dialog box. In the pop-up dialog box, enter the information of the material to be tested and click "OK" to exit;
6. Click on the menu bar of the "Parameter Settings-> Test Methods", and then select the pop-up dialog box has been edited. Edited test method, or you can click "Modify" to modify the currently selected test method, or click "Add" to add a new test method, enter the test method to be used in the pop-up dialog box and click "OK" to exit. "OK" to exit;
7. Set up a good material information and experimental methods can be clicked on the "Start" button to start the test;
8. Do not click on any buttons in the test process, until the material breaks or reaches the shutdown If you do not reach the automatic shutdown conditions, you can also press the "Test" or "Stop" button to end the test.
9. At the end of the test, a dialog box will pop up whether to save the results, if you need to save then click "OK" and enter the file name to save the test data.
10. After the completion of the test, you can click on the main interface of the "test results & customized reports" options page in the "Report Settings" button to set up the report;
11. After setting up the report, if you have a printer connected to it, you can click on the "Print" button. You can click the "Print" button to print out the report. First, the use of salt spray testing machine environmental requirements
1, the equipment must have more than 600mm of space around.
2, the temperature around the equipment should be maintained between 15 ℃ ~ 30 ℃.
3, equipment without direct sunlight or other heat sources of direct radiation
4, equipment turnover without strong airflow, when the surrounding air needs to be forced to flow, the airflow should not be blown directly onto the box.
5, no high concentration of dust and corrosive substances around the equipment.
6, equipment, power supply voltage fluctuations ≤ ± 10%.
Two, salt spray tester precautions
1, please confirm the power supply connection before the operation of the equipment.
2, automatic water supply system to confirm.
3, gas supply system to confirm.
4. Confirm the sealing of the isolation tank.
5. Checking of venting holes.
6. When preparing salt solution, please use analytical pure grade NaCl and evaporated water or deionized water to prepare, and make it ready to use.
7, after each test, should cut off the power supply, gas source, water source, to avoid the equipment in a long time in a charged standby state.
Three, salt spray tester routine maintenance
1, the end of each test, it is recommended to use water to clean the equipment test chamber (including: spray room, salt solution room, preheating water tank and sealing water tank), in order to keep the equipment clean.
2, each test or the end of the test, the standard measuring cup of the solution should be poured out and cleaned in a timely manner, so as to avoid the accumulation of salt solution crystals, affecting the calculation of the amount of sedimentation.
3, clean the box, please note:
(1), the temperature sensor of the protective layer of protection.
(2) The protection of the glass filter and glass nozzle (do not use a needle or any hard object to unclog the filter or nozzle).