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 description of the common fault repairs for metal Vickers hardness testers. 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.
The common faults and treatment methods for repairing Vickers hardness testers are as follows:
1. Load indicator light and measurement microscope light are not bright First check if the power supply is connected, then check the switch, light bulb, etc. If you do not shine after excluding these factors, it is necessary to see if the load is all plus or if the huang piece switch is normal. After the exclusion is still not normal, you must start 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. After the adjustment is still unclear, the objective lens and the 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 is on the problem, then remove it, wipe it with long-fiber cotton wool with absolute alcohol, and install it in 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 slightly rotating the table, the position of the indentation changes greatly. The reason for this situation is caused by the different axes of the indenter, the measuring microscope and the workbench. 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 to make the working shaft and the main shaft concentric. After adjusting, press an indentation on the test block. Observe its position in the microscope and record it; 3 Gently turn the table to ensure that the test block does not move on the table. Under the microscope, find a point on the test block that does not rotate. This point is the axis of the table; Loosen the screws and bottom screws 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, then tighten the platen screw and adjusting screw to press out a pressure. Traces are cross-referenced. Repeat the above steps until they are completely coincident.
4, the reasons for the detection of the value of the error and the solution 1 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 The load is beyond the requirements of the regulations or the load is unstable. Check with a small load third-class dynamometer. If the load exceeds the requirement by ±1.0% but the direction is the same, this situation is a change in the proportion of the lever. 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 match the shaft steel ball. See step 3 for the adjustment of the coaxial core.
5. There is an impact phenomenon when loading. This happens when the buffer oil is too little or the oil is too dirty. It can usually be solved after filling up with oil or cleaning the buffer.