Common faults of valve drilling and tapping machines are as follows:
Drilling related faults:
Drill bit breaks or wears too quickly:
Reason: The drill bit is of poor material and insufficient hardness, which cannot adapt to the processing of valve materials; the processing parameter settings are unreasonable, such as too high speed and too fast feed speed, causing the drill bit to bear too much cutting force; the drill bit is not installed firmly and shakes during processing; there are hard points or inclusions inside the valve material, which makes the drill bit subject to uneven cutting force.
Solution: Replace the drill bit with better quality and suitable for valve materials; according to the characteristics of valve materials and drill bits, reasonably adjust the processing parameters such as speed and feed speed; ensure that the drill bit is firmly installed, and check and tighten the drill bit regularly.
Inaccurate drilling position:
Reason: The fixture is not positioned accurately, and the valve workpiece cannot be correctly fixed in the processing position; the coordinate axis accuracy of the machine tool deviates, resulting in the offset of the drilling position; programming error, the input drilling position coordinates are incorrect.
Solution: Check and adjust the fixture to ensure its positioning accuracy; perform precision detection and calibration on the coordinate axis of the machine tool; carefully check the programming code to ensure the accuracy of the drilling position coordinates.
Inconsistent drilling depth:
Cause: Failure of the machine tool's feed system, such as screw wear, excessive guide rail clearance, etc., resulting in unstable feed rate; during processing, the valve workpiece moves or deforms; the drill bit has inconsistent length or different degrees of wear.
Solution: Check and repair the machine tool's feed system, replace the worn screw and adjust the guide rail clearance; strengthen the fixation of the valve workpiece to prevent it from moving or deforming during processing; regularly check and replace the drill bit to ensure that the length and degree of wear of the drill bit are consistent.
Tapping-related failures:
Poor thread quality:
Cause: The tap is worn or improperly selected, the cutting edge of the tap is not sharp or the pitch does not match the processing requirements; the speed and feed speed during tapping are not suitable, resulting in incomplete thread shape or dimensional deviation; insufficient cooling and lubrication, causing the tap to overheat during processing, affecting the thread quality.
Solution: Replace the worn tap in time, select the appropriate tap according to the valve thread specifications; adjust the speed and feed speed during tapping to adapt it to the tap and valve materials; ensure sufficient cooling and lubrication, and use appropriate coolant or lubricant.
Tap breakage:
Reason: The tap encounters hard spots or inclusions during tapping, causing a sudden increase in cutting force; the feed speed during tapping is too fast, causing the tap to bear too much torque; the quality of the tap is poor and the strength is insufficient; improper operation during reverse thread withdrawal causes the tap to be subjected to reverse impact force.
Solution: Before tapping, check the valve material to remove hard spots and inclusions; reduce the feed speed during tapping to avoid excessive torque on the tap; select a tap with good quality and high strength; operate slowly during reverse thread withdrawal to avoid reverse impact force on the tap.
Electrical system failure:
Motor failure:
Reason: The motor is overloaded and overheated due to long-term high-load operation; the power supply voltage of the motor is unstable, and too high or too low voltage will affect the normal operation of the motor; the motor winding is short-circuited or open-circuited, which may be caused by motor aging, insulation damage, etc.
Solution: Check the load of the motor to avoid overload operation; ensure that the power supply voltage is stable, and install a voltage stabilizer if necessary; repair the motor and replace damaged windings or motors.
Control system failure:
Cause: Hardware failure of the control system, such as damage to electronic components such as controllers and drivers; errors in the control program, resulting in the inability of the machine tool to operate normally; sensor failure, unable to accurately feedback the operating status of the machine tool.
Solution: Check and replace damaged electronic components; check and debug the control program to fix errors; check and replace faulty sensors.
Mechanical structure failure:
Guide rail wear:
Cause: The machine tool has been used for a long time, and the friction and wear of the guide rails have caused its accuracy to decrease; insufficient lubrication of the guide rails has aggravated the degree of wear.
Solution: Regularly maintain and maintain the guide rails and add lubricating oil; if the guide rails are severely worn, they need to be repaired or replaced.
Transmission component failure:
Cause: The transmission components such as belts and chains are loose, worn or broken, affecting the transmission efficiency and accuracy of the machine tool; improper installation or damage of the coupling leads to loose connection between the shafts.
Solution: Regularly check and adjust the transmission components, replace worn or broken belts and chains; correctly install and maintain the coupling to ensure its firm connection.
Hydraulic or pneumatic system failure:
Hydraulic system failure:
Cause: Hydraulic pump failure, unable to provide sufficient hydraulic pressure; Hydraulic valve is blocked or damaged, causing the hydraulic system to fail to work properly; Hydraulic cylinder leaks, affecting the working performance of the machine tool.
Solution: Check and repair the hydraulic pump, replace damaged parts; Clean or replace the hydraulic valve; Overhaul the hydraulic cylinder and replace the seal.
Pneumatic system failure:
Cause: Insufficient air source pressure, causing pneumatic components to fail to work properly; Pneumatic valve failure, such as valve core stuck, air leakage, etc.; Loose or broken air pipe connection, causing gas leakage.
Solution: Check the air source pressure to ensure that it meets the working requirements of the machine tool; Repair or replace the faulty pneumatic valve; Check and tighten the air pipe connection, and replace the broken air pipe.
