First. The operation sound of the electric forklift is abnormal
1. The screws of the fasteners of the electric forklift are loose, the guide wheels and rollers of the car body are seriously worn, and the gap is too large;
2. The wear gap between the chain and the pin shaft of the chain piece is too large or the gap between the upper and lower staples of the fork and the fork beam is too large;
3. Check whether the conflict and rolling gap between the guide wheel, the roller and the gantry is too large. Whether the cooperation gap between the fork and the fork frame beam is too large, these factors will cause abnormal sound when the electric forklift is in use;
4. Check whether the tire screws of the electric forklift are loose, whether the bearings are damaged, etc.;
5. The electric forklift gear pump fails, such as air entering the pump from the oil suction pipe or seal, the resistance of the oil suction pipe is too large, or even partially blocked. Gear pump accuracy is not high. The pump and the coupling are not coaxial.
Maintenance method: add appropriate lubricating oil to the connection, if the abnormal noise is reduced, it means a leakage problem, just tighten the joint or replace the sealing ring directly; if there is no change, check the gear accuracy, carry out research and adjustment, and if necessary Change gears. Finally, check the coaxiality between the pump and the coupling, pay attention to the difference between the working state and the static state, and adjust according to the technical requirements.
There are many reasons for the abnormal sound of electric forklifts. Forklift maintenance personnel should test and find the reasons one by one, so as to fundamentally solve the problem of abnormal forklift sound.
Second. The speed of the driving wheel of the electric forklift is significantly reduced or the driving motor is seriously overloaded
cause of issue:
1. The battery voltage of the electric forklift is too low or the contact resistance of the pile head is too large;
2. Carbon deposits between the motor commutator sheets cause short circuit between sheets;
3. Improper adjustment of the motor brake causes the motor to run with braking;
4. The drive head gearbox and bearings are short and smooth or the base is blocked; the motor armature is short-circuited.
Maintenance method: check the battery terminal voltage or clean the pile head when the stacker is loaded; clear the commutator; adjust the brake clearance; check and clean and refill the lubricating oil to remove the jamming phenomenon; replace the new electric forklift motor.
Third. The electric forklift is weak or unable to lift cause of issue:
1. The gear pump and pump lift of the electric forklift are excessively worn;
2. The high pressure of the relief valve in the reversing valve is improper;
3. Oil leakage in the oil pressure pipeline;
4. The hydraulic oil temperature is too high;
5. There is a jamming phenomenon on the gantry carriage;
6. The speed of the oil pump motor is too low.
Maintenance methods: replace the excessively worn gear pump; readjust the relief valve; check the oil pressure pipeline and repair it; replace the unqualified hydraulic oil and check the cause of the oil temperature rise; check and adjust; check the motor and clear the fault.
Fourth, electric forklift working device and hydraulic system failure
1. Reasons for the failure of vibration during hoisting: there is air in the hoisting cylinder, oil leakage in the hydraulic system, excessive wear of the inner gantry fork rollers and gantry bearings, uneven tension of the two hoisting chains, etc.
2. The lifting speed is too slow or cannot be lifted. Causes of failure: lack of oil in the fuel tank, blockage of the oil filter, failure of the safety valve, high temperature of the hydraulic oil, too thin of the hydraulic oil, oil leakage in the hydraulic pipeline, damage to the hydraulic pump, etc. The abnormal noise when the gantry is lowered is generally due to damage or aging of the shockproof rubber.
Maintenance method: First check the joints, gaskets of each component and whether there is oil leakage inside the structure, if any, replace it; bleed the system, if it still cannot be eliminated, disassemble and inspect the lifting hydraulic cylinder, gear pump and other parts. If the working condition of the safety valve fails, repair or replacement is required.
3. Lifting and jumping, the gantry is jumping when lifting. Causes of failure: There is air in the lifting hydraulic cylinder; the gear pump performance is poor; the forklift reversing valve is inflexible; the oil is not clean. Maintenance method: First, loosen the bleed screw plug on the hoisting hydraulic cylinder to release the air in the hoisting cylinder; check the cleanliness of the oil. If the jumping still cannot be removed, check the working condition of the reversing valve and gear pump. If they are not working well, they should be repaired or replaced directly.
Five, the electric forklift can not walk
1. First check the forklift battery of the electric forklift to see if there is any voltage. If the voltage is there, check whether the voltage can be used normally. Maintenance method: If the battery has no voltage or the voltage is too low, charge the battery directly.
2. Check whether the lift switch and line of the accessories are loose or short-circuited, and whether the micro switch is damaged. Maintenance method: repair and clean the line, replace or repair the micro switch.
3. Check whether the lifting contactor assembly is burnt out or the coil is short-circuited or open-circuited. Maintenance method: Repair the platinum contact of the contactor or directly replace a new hydraulic contactor assembly.
4. Check whether the lifting module is burnt out or is short-circuited or open-circuited. Maintenance method: Repair or replace the module assembly.
5. Check whether the hydraulic motor has voltage, check whether the motor has short circuit or open circuit and leakage, and check whether the carbon brush has serious wear and so on. Maintenance method: repair the line, replace the carbon brush of the motor and the copper head of the motor, repair the hydraulic motor assembly or replace the new hydraulic motor.
6. Check whether the hydraulic pump, multi-way valve, oil pipe and oil cylinder of the electric forklift are damaged. Maintenance method: Check and repair the hydraulic pump of the electric forklift for damage or directly replace the new hydraulic pump assembly. If the multi-way valve is damaged, repair or directly replace the new multi-way valve assembly, directly replace the new hydraulic oil pipe, and replace the oil cylinder. Repair kit or replace with new cylinder assembly.
7. The electrical part of the electric forklift is faulty, suddenly there is no forward and backward \lift without any response, the forklift is rushing and rushing, the forward speed cannot be adjusted, etc.
Six, other electric forklift failure and maintenance methods
1. The main reasons for the free sliding too fast when there is a load are: oil leakage in pipelines and joints, or serious wear of the valve hole of the multi-way valve, the sliding valve stem or the seal ring, and the internal leakage; etc.
2. The front and rear tire screws are loose, the wheel hub bearing is damaged, the rear axle plane bearing and needle roller bearing are damaged, etc., there will be abnormal conditions during driving work.
3. Abnormalities in all parts of the whole vehicle should be eliminated one by one, and after a test drive inspection finds problems, reasonable maintenance and treatment should be carried out to solve the problem.
4. Braking deviation. The reason for this failure is that the braking force of the left and right wheels is unbalanced, which makes the forklift bias to one side when braking. When braking, which side grabs forward, it is necessary to check the braking gap or master cylinder condition of which side. The deviation is irregular, suddenly left and right, if the brake is to the left and then to the right, you should check the braking condition of the left wheel first, otherwise, check the right wheel. Finally, there is oil on the brake shoe pads or the brake drum.
5. Oil leakage (including external leakage and internal leakage). The oil leakage of the master cylinder and wheel cylinder is mostly due to the leakage of the leather cup and the aprons due to wear and tear due to the excessive use time. If the brake pedal feels light when you step on the brake pedal, it is generally because the master cylinder cup is worn and leaking oil; the piston cup, apron or piston pushrod sealing ring of the supercharger booster cylinder and the poor sealing of the control valve cup will all cause problems. Oil leakage; if the brake shoe is too thin or the brake clearance is too large, when the brake pedal is pressed hard, the wheel cylinder cup will turn over and cause oil leakage.
6. It is very laborious to step on the brake pedal. Cause of failure: The master cylinder cup or the master cylinder piston seal is swollen. The copper tube between the master cylinder and the supercharger is deformed or flattened, which makes the inner hole smaller and the oil flow is not smooth. The copper tube leading to the wheel cylinder is deformed, resulting in a smaller hole diameter and poor oil flow. The sealing ring of the control cylinder swells, and the brake fluid deteriorates and becomes too viscous to make the fluidity worse.
7. Excessive consumption of forklift brake fluid
1) Check whether there is oil leakage in each pipeline;
2) The brake spool valve cup in the shift control valve of the forklift transmission leaks oil, and the brake fluid enters the transmission. At this time, the smell of the brake fluid can be smelled from the transmission oil quantity inspection hole;
3) The poor sealing of the piston cup of the booster cylinder of the vacuum supercharger, the sealing ring or the sealing ring of the piston push rod and the cup of the control valve will cause excessive consumption of brake fluid.
Seven, electric forklift maintenance precautions
1. Forklifts need regular inspection and maintenance to keep them in good condition; some key safety parts and vulnerable parts should be replaced regularly as required.
2. Try to use genuine parts matching the electric forklift brand to replace or add hydraulic oil or butter, do not use different types of oil.
3. If you find that the electric forklift is damaged or malfunctioning, you should report it to the equipment management personnel, and do not use the faulty forklift.
4. It is forbidden to repair the forklift without professional maintenance training.