What are the common faults of plate shearing machines? How to quickly troubleshoot them?

Plate shearing machines are an indispensable piece of equipment in the metal processing industry, widely used in sheet metal processing, machinery manufacturing, construction, shipbuilding, and other fields. However, during long-term use, plate shearing machines inevitably experience various faults. If these faults are not promptly investigated and addressed, they can not only affect production efficiency but also lead to equipment damage or even safety accidents. Therefore, understanding common plate shearing machine faults and mastering quick troubleshooting methods is crucial for operators and maintenance personnel.

1. Analysis of Common Plate Shearing Machine Faults
(1) Shearing stops or abnormal movement
This is one of the most common faults during the use of plate shearing machines. Common causes include:
Insufficient hydraulic oil or blocked oil circuit
Motor not started or motor malfunction
Damaged hydraulic pump
Abnormal electrical control circuit
This usually manifests as slow shearing action, complete stagnation, or only occasional operation.

(2) Insufficient shearing force, unable to cut the plate
Insufficient shearing force will cause the equipment to fail to complete the cutting normally. Common reasons are as follows:
Insufficient hydraulic system pressure
Improper adjustment of the overflow valve
Insufficient pressure output due to wear of the hydraulic pump
Aging or excessive impurities in the hydraulic oil

(3)Inaccurate shearing angle and non-straight cut
If the cutting accuracy of the plate shearing machine decreases, it is often manifested as increased burrs on the cut, bent cutting lines, or inaccurate dimensions. Common causes include:
Wear of upper and lower blades
Incorrect blade gap
Deformation of the machine body or unstable installation
Loose back gauge or motor failure

(4) Increased equipment vibration or noise
Abnormal vibration or noise during the operation of the plate shearing machine is a typical signal of mechanical structure problems:
Loose bolts
Wear of internal parts of the hydraulic pump
Lack of lubrication of various moving parts
Unstable installation foundation

(5) Excessive hydraulic oil temperature
Excessive heat generation in the hydraulic system will affect the stability and service life of the plate shearing machine. Common causes include:
Poor oil quality or low oil quantity
Continuous high load operation of the hydraulic pump
Cooling system failure
Stuck hydraulic valve

2. Quick troubleshooting methods
For different types of faults, we can quickly diagnose and handle them from the following aspects.

(1) Hydraulic system troubleshooting
The hydraulic system is the core of the plate shearing machine, and most faults are related to it. The troubleshooting steps are as follows:

1) Check the hydraulic oil level and quality
Insufficient oil will cause unstable pressure. If the oil is black, has an unusual odor, or contains impurities, it should be replaced immediately.

2) Check the pressure gauge reading
Ensure the system pressure is within the standard range. If it is too low, check if the relief valve is improperly adjusted.

3) Check the hydraulic pump's operating condition
If there is obvious noise, overheating, or the pressure cannot rise, it may be due to internal wear.

4) Check for oil circuit blockage
A clogged filter will cause poor oil flow and needs to be cleaned or replaced promptly.

(2) Electrical system troubleshooting
Electrical faults usually cause equipment to fail to start or malfunction.

1) Check the power supply
Ensure the power supply wiring is stable and the voltage is normal.

2) Check the contactors and relays
If there is poor contact or burnt contacts, they should be replaced promptly.

3) Check the limit switches
A malfunctioning limit switch may prevent the shearing action from being performed.

4) Check the motor
If the motor is overheating, making abnormal noise, or not rotating, check the windings or bearings.

(3) Blade and Mechanical Structure Inspection
Mechanical wear directly affects the shearing effect.
1) Check blade wear
Dull blades will result in uneven cuts; sharpen or replace blades regularly.

2) Adjust blade gap
Different thicknesses of sheet metal require different blade gaps; improper adjustment will affect cutting quality.

3) Check transmission components
Moving parts such as sliders and connecting rods must be kept lubricated to prevent jamming and wear.

4) Check machine body and anchor bolts
Ensure the equipment is securely installed to avoid vibration affecting accuracy.

(4) Fault Prevention and Maintenance Recommendations
To reduce shearing machine malfunctions, daily maintenance is crucial:
Regularly change hydraulic oil and filters
Check bolts for looseness every shift
Keep blades sharp
Avoid forced shearing of excessively thick sheet metal
Regularly check electrical components
Keep equipment clean
Good maintenance can significantly extend equipment life and reduce the failure rate.

Common shearing machine malfunctions mainly focus on three parts: the hydraulic system, the electrical system, and the mechanical structure. Understanding the causes of malfunctions and being able to quickly troubleshoot them can help companies reduce downtime and improve production efficiency. With proper maintenance and operation, shearing machines can maintain stable operation for a long time, providing efficient and reliable support for metal processing.