Vickers Hardness Tester Common Faults And Maintenance Methods

- Jan 17, 2019-

There are many types of hardness testers. The most commonly used metallurgy, Brinell and Vickers hardness testers are used in industrial and mining enterprises and research institutes. Among them, metal Rockwell and metal Brinell hardness testers are compared with metal Vickers hardness. The meter structure is simple. The repair of common faults is not very difficult. The following is a general troubleshooting of the metal Vickers hardness tester. According to years of work practice, it is necessary to start from the level of the adjustment workbench before starting the verification and repair work, and then observe whether the main shaft, the lever, the lifting screw, the buffer mechanism and the measuring device are normal and flexible. Ensure a basic understanding of device performance. Then solve the problem one by one. (1) The charging indicator and the measuring microscope light are not lit. First check if the power supply is connected, and then check the switch, light bulb, etc. If you do not shine after removing these factors, it is necessary to see if the load is fully added or if the reed switch is normal. After the exclusion is still not normal, it must be gradually checked from the line (circuit). (2) Measuring turbidity in the microscope, invisible or invisible. This should be done by adjusting the focal length and light of the microscope. If the adjustment is still unclear, the objective lens and eyepiece should be rotated separately, and the dotted line and solid line should be moved separately. Three flat mirrors of the engraved line, carefully observe which mirror surface the problem is on, then remove it, wipe it with long-fiber absorbent cotton dipped in anhydrous alcohol, and install it in the reverse order. If it is still not solved, send it for repair. Or replace the micrometer microscope. (3) The indentation is not in the field of view or the table is slightly rotated, and the position of the indentation varies greatly. This is caused by the difference in the axis of the indenter, the measuring microscope, and the table. Since the indenter is fixed to the bottom end of the working shaft, it is adjusted separately in the following order. 1Adjust the movable clearance at the lower end of the main shaft so that the lower end surface of the guide seat does not directly contact the taper surface of the main shaft. 2 Adjust the side screw of the rotating shaft so that the working shaft and the main shaft are the same (axis). After adjusting, press a pressure on the test block. Trace, observe its position in the microscope, and record; 3 gently turn the table (make sure the test block does not move on the table) under the microscope to find a point on the test block that does not rotate, this point is the table axis 4; slightly loosen the screw and bottom screw on the lifting screw pressure plate, gently move the entire lifting screw so that the axis of the table coincides with the position of the indentation recorded in the measuring microscope, and then tighten the platen screw and adjusting screw. Press an indentation against each other. Repeat the above steps until they are completely coincident. (4) Reasons for the detection of the value of the deviation and the solution 1 The measurement microscope scale is not allowed. Check with a standard micrometer. If it is not allowed to be repaired or replaced. 2 diamond indenter defect. Observe with an 80-fold stereo microscope to see if it meets the requirements of the diamond indenter verification procedure. Replace the indenter if there is a defect. 3 negative (load) load exceeds the requirements of the regulations or the load is unstable, and is checked with a small load third-class dynamometer. If the load exceeds the requirement (±1.0%) but the direction is the same, this situation is a change in the lever ratio. The spindle protection cap can be loosened, the force point contact is rotated, the load (lever ratio) is adjusted, and the tightening is adjusted. If the load is unstable, it may be caused by the blunt force of the blade, the wear of the fulcrum ball or the difference between the working axis and the spindle, and the large friction in the working shaft. At this time, check the blade and the steel ball. If it becomes dull or worn, it should be trimmed or replaced. Check the working shaft and clean it. Be sure to pay attention to the shaft steel ball. See step 3 for the adjustment of the same shaft. (5) Impact phenomenon during loading This situation is related to too little buffer oil or too dirty oil. After filling up the oil or cleaning the buffer, the fault type can generally be solved: 1. The fault of the charging indicator and the measuring light is not bright; 2. The turbidity in the measuring microscope can not be seen or the indentation can not be seen; 3. The indentation Not in the mind or slightly turning the table, the position of the indentation changes greatly. Solution 1. First check if the power supply is connected, then check the switch, light bulb, etc. If you eliminate these factors or not, you should check whether the load is fully added or the reed switch is normal. 2. This should start from adjusting the focus and light of the microscope. After the adjustment is still unclear, turn the objective lens and the eyepiece separately, and move the three flat mirrors with dashed lines, solid lines and engraved lines in the mirror separately, and carefully observe the problem. On which mirror surface, then remove it, wipe it with absorbent cotton with absorbent cotton. 3. The reason for this situation is caused by the different axes of the indenter, the measuring microscope and the workbench, as long as the instructions are adjusted in order according to the instructions.