Introduction to and symbolic representation of coaxiality
1. Coaxiality is a mechanical term for the positioning tolerance in the form and position tolerance of parts. The relevant elements are between shafts, holes, and holes. They require the same straight line, or concentricity, that is, to control the degree of deviation between the actual axis and the reference axis!
2. Its symbol is represented by two concentric circles: ◎
Possible adverse consequences of large coaxiality error
Coaxiality error is the eccentricity of the center of the circle reflected on the cross section. If parts with large coaxiality error are installed and used, they may not be installed during assembly. The assembled machine may produce vibration, shaking, periodic noise, unstable suction, damage to machine parts, and in severe cases, safety accidents and other mechanical defects. Therefore, the control of part coaxiality has always been an important project of Junhua Special Plastics Quality Inspection.
Part types for coaxiality measurement
Coaxiality measurement must be for rotating parts, such as shafts, gears, sleeves and other parts.
Instruments used for testing
Coaxiality is difficult to measure. The instruments we use include imagers, three-coordinate measuring machines, deflection meters, V-shaped irons, dial indicators, special fixtures and other instruments.
Measurement methods
Coaxiality testing is a test item we often do in our measurement work. The following is a brief introduction to the coaxiality testing methods of shafts and gears produced by the company.
1. Turn on the computer and place the part to be measured on the workbench
2. Turn on the flash test button in the computer and import the program
3. Click the outer circle and inner hole of the object to be measured with the mouse, and click the measurement button
4. Read the coaxiality data, record it, and fill in the test report!
1. First identify the drawing and find the reference.
2. Clamp the part to be measured on the three-coordinate platform and fix it firmly.
3. Open the three-coordinate measuring machine, calibrate the side head, turn on the computer, find the corresponding measurement software, open the software, and then program it.
4. Start measuring the product, establish the coordinate system, and measure the outer circle.
5. Define the benchmark, evaluate the measured cylinders, and then you can see the coaxiality.
6. Export the test report.
1. Wash the measured piece with warm water and wipe it dry with a dry cloth.
2. Adjust the distance between the two tips of the deflection meter, which is about 8 mm shorter than the shaft parts to be measured. Align the center hole of one end of the measured workpiece with the fixed tip of the deflection meter. Hold the workpiece with your left hand, and use your right hand to compress the handle of the moving tip at the other end of the deflection meter to make the moving tip shrink backwards. With the left and right hands in coordination, push the moving tip into the center hole at the other end of the measured workpiece!
3. Turn the measured object by hand. It should be easy to turn, but the gap should not be too large. Make sure the tightness of the measured object is appropriate! Otherwise, the test result will be inaccurate. If you need to adjust the tightness, please refer to the above 2nd item.
4. Install the dial indicator, dial base, and dial stand, and adjust the dial indicator so that the probe contacts the outer surface of the workpiece to be measured, and there is a compression of 0.5-1 circle.
5. Slowly and evenly rotate the workpiece by hand for one circle, and observe the fluctuation of the dial indicator pointer. Take the difference between the reading Mmax and the reading Mimin as the coaxiality error of the section, and record the data.
6. Move the dial indicator bracket, select an outer circle, rotate the measured part, measure four different positions according to the above method, and take the MAX value of the difference between the reading Mmax and the reading Mimin measured at each place as the coaxiality error of the part.
7. Complete the test report and organize the experimental equipment.
1. Wash the tested piece with warm water and wipe it dry with a dry cloth.
2. Prepare two V-shaped blocks with the same height and the same cutting edge, and place the prepared V-shaped blocks on a marble slab or a very flat machine workbench.
3. Place the benchmark of the workpiece to be measured in the V-groove of the instrument
4. Install the dial indicator, dial base, and dial stand, and adjust the dial indicator so that the probe contacts the measured outer surface of the workpiece and there is a compression of 0.5-1 circle
5. Press down with your hand and slowly and evenly rotate the workpiece for one circle, and observe the fluctuation of the dial indicator pointer, take the difference between the reading Mmax and the reading Mimin as the coaxiality error of the section, and record the data.
6. Then move the dial base, select an outer circle, rotate the measured part, measure four different positions according to the above method, and take the MAX value in the difference between the reading Mmax and the reading Mimin measured at each place as the coaxiality error of the part
7. Complete the test report and organize the experimental equipment.
1. First calculate the coaxiality error value on a single measurement section, that is, Δ =Mmax – Mmin.
2. Take the MAX value of the coaxiality error value measured on each section as the coaxiality error of the part.
3. Complete the measurement according to the above steps and fill in the relevant information and measurement results of the measured part into the corresponding test report, and use this as a reference to determine whether the coaxiality error of the part is qualified.
Jiangsu Chaoju has many other testing means and methods, which will not be elaborated here. Jiangsu Chaoju is a company with a full industrial chain that integrates PEEK (polyetheretherketone) resin polymerization, continuous extrusion molding of profiles such as plates, rods, and tubes, and research and development, production, and sales of finished parts. PEEK (polyetheretherketone) is widely used in aerospace, national defense, military industry, automobile manufacturing, electronics, medical and other fields due to its excellent comprehensive performance. The company’s machining equipment includes imported five-axis CNC, four-axis CNC, three-axis CNC, imported turning and milling composite, CNC lathe, gear hobbing machine and other precision processing equipment to escort your product quality. Welcome to call us for consultation and discussion. Chaoju is willing to work with people from all walks of life to create a better future for Chaoju PEEK!