Forklift driver safety technical knowledge
1. What is the maximum lifting capacity and load center? What is their relationship?
Answer: when the center of gravity of the goods and the load center are in the same plumb line, the maximum weight that the forklift can load and unload the goods is called the maximum lifting capacity of the forklift; The horizontal distance between the center of gravity of the standard load and the front wall of the vertical section of the forklift is called the load center of the forklift. Generally, the load center is specified in the design according to the standard, that is, the load center of forklift with different lifting capacity is different in general. When the center of gravity of the goods is within the scope of the load center, the forklift can carry out loading and unloading with the maximum lifting capacity, otherwise the stability of the forklift will be damaged and accidents will easily occur.
2 what is the stability of forklift?
Answer: the stability of forklift refers to the ability of forklift to resist overturning during loading and unloading and driving on various roads. It can be divided into longitudinal stability and transverse stability. Longitudinal stability refers to the ability of forklift to resist longitudinal rollover around the axle. Lateral stability refers to the ability of forklift to resist rollover and sideslip.
3. How to stop the forks and gantry after forklift operation?
Answer: after the forklift works, the forklift must be lowered to the ground, and the gantry should return to its original position (vertical in the middle). The purpose is to enable the hydraulic system to obtain unloading protection, so as to avoid the deformation and damage of various components (especially sealing components) in the hydraulic system due to long-term pressure.
4. What are the reasons for the shaking of the forklift gantry and the automatic forward and backward inclination of the gantry?
Answer: causes of jitter:
(1) The clearance between the portal support pin shaft and the copper sleeve is too large
(2) The clearance between sliding steel plates of inner and outer door frames is too large
(3) The tightness of the two starting chains is different
(4) Excessive wear of roller
Causes of automatic tilt back and forth:
(1) The seal of the tilt cylinder is damaged
(2) Multi way valve manifold leakage
5. What is the reason why the fork automatically slides after lifting?
Answer: (1) the piston cup is aged or damaged
(2) The clearance between lifting cylinder and piston is too large
(3) The clearance between the lifting valve barrel of the hydraulic distributor and the lifting valve rod is too large
(4) Oil leakage in pipeline or joint
6. What are the reasons why the fork lifting speed is too slow and cannot be lifted?
Answer: reasons for slow lifting:
(1) Wear or oil leakage of oil pump
(2) The spring pressure of distributor safety valve is too low or the steel ball and valve seat are worn
(3) The clearance between the lifting valve barrel of the distributor and the lifting valve rod is too large
(4) The clearance between the lifting cylinder and the piston is too large, or the leather cup is aging and damaged
(5) Oil leakage in pipeline or joint
(6) One way throttle valve does not work
Reasons why forks cannot be lifted
(1) The oil tank is short of oil
(2) The oil pipe joint is blocked or has serious oil leakage
(3) Oil pump damaged
(4) The safety valve spring is broken or permanently deformed
7. What are the types of forklift maintenance? What is the time interval?
A: the maintenance of forklift truck is divided into four categories: daily maintenance, first level maintenance, second level maintenance and third level maintenance. Daily maintenance is the maintenance to be carried out every day. Generally, the first level maintenance is carried out after every 50 hours of work, the second level maintenance is carried out after every 200 hours of work, and the third level maintenance is carried out after every 600 hours of work.
8. What is the daily maintenance content of forklift?
A: the specific contents include:
(1) Check the amount of oil in the engine crankcase and air filter, the amount of fuel in the fuel tank and the cooling water in the radiator. If it is insufficient, add it as required.
(2) Check the height of electrolytic liquid level in the battery, add it if necessary, keep the air hole of the cover unblocked, and the pole is tightly and firmly connected with the wire connector.
(3) Check the free travel and working reliability of hydraulic brake and handbrake, fill brake fluid and remove air from the system as necessary.
(4) Check the tire pressure and remove the sundries embedded in the tread.
(5) Check the working oil volume in the oil tank of the vehicle hydraulic system and whether there is leakage at the pipeline, joint, etc.
(6) Check the water level of the fire extinguishing water tank.
(7) Check the operation of instruments, lights, horns, etc.
(8) After the above inspection, start the engine, check the operation of the engine, and check whether the transmission system, braking system and hydraulic lifting system work normally.
9. What are the main contents of forklift primary maintenance?
Answer: (1) check the oil quantity, oil viscosity and dirt level in the engine oil.
(2) Clean the battery and add distilled water as necessary.
(3) Check the appearance and tightness of the fan belt.
(4) Check whether the water pump and drive axle work normally.
(5) Add oil or grease to each part of the clutch and brake longitudinal connecting rod as required.
(6) Check the wear of the piston rod of lifting cylinder and tilt cylinder. If there are slight scratches, they can be polished with oilstone or fine abrasive cloth.
(7) Check and tighten the bolts and nuts of the tire.
10. What are the main operation contents of forklift secondary maintenance?
Answer: (1) clean the engine oil pan, crankcase and the inside of the oil filter, and replace with new engine oil.
(2) Clean the fuel tank and check whether the joints of fuel pipeline and oil pump are loose and leaking.
(3) Check the power-off contact of the distributor and adjust the phase gap.
(4) Check and tighten the bolts at all exposed parts of the generator.
(5) Check the discharge of the battery and charge it as necessary.
(6) Replace the cooling water in the radiator.
(7) Check and adjust the free travel of clutch and brake pedal and the braking clearance of wheel brake.
(8) Drain the precipitated sundries and ponding at the bottom of the working oil tank, clean the filter screen and add new oil as appropriate.
(9) Check whether the tightness of the two lifting chains is consistent.
(10) Check whether there is deformation, cracking and other phenomena on the iron block of the forklift and the heel of the forklift.
11. What are the main operation contents of forklift three-level maintenance?
Answer: (1) adjust the valve clearance.
(2) Measure the cylinder pressure and check the cause of nonconformity.
(3) Check the working performance of the clutch and adjust it as necessary.
(4) Check the free stroke of the steering wheel and the connection of the steering tie rod, and check the wear of the steering knuckle pin and the pin shaft of the steering sector boom.
(5) Check the bearing wear of clutch and brake pedal shaft.
(6) Thoroughly clean the forklift, and check and tighten the bolts and nuts of all exposed parts.
12. What are the safety operating procedures for forklifts?
Answer: (I) check the vehicle
(1) Before forklift operation, the appearance shall be checked and fuel, lubricating oil and cooling water shall be filled.
(2) Check the startup, operation and braking performance.
(3) Check whether the light and sound signals are complete and effective.
(4) During the operation of forklift, check whether the pressure and temperature are normal.
(5) After the forklift is running, the leakage shall also be checked and the seals shall be replaced in time.
(6) In addition to the above contents, the battery forklift shall also check the circuit of the battery forklift according to the relevant inspection contents of the battery forklift.
（2） Start
(1) Before starting, observe the surroundings and confirm that there are no obstacles hindering driving safety. Whistle first and then start.
(2) For vehicles with pneumatic braking, the reading of the brake barometer must reach the specified value before starting.
(3) When the forklift starts with load, the driver should first confirm that the load is stable and reliable.
(4) Start slowly and smoothly.
（3） Driving
(1) When driving, the height between the bottom end of the fork and the ground shall be 300-400mm, and the gantry shall be tilted back.
(2) Do not raise the fork too high when driving. When entering or leaving the operation site or driving, pay attention to whether there are obstacles in the sky. When the load is running, if the fork rises too high, it will increase the overall center of gravity height of the forklift and affect the stability of the forklift.
(3) After unloading, lower the fork to the normal driving position before driving.
(4) When turning, if there are pedestrians or vehicles nearby, send a signal and prohibit sharp turning at high speed. Sharp turning at high speed will cause the vehicle to lose lateral stability and roll over.
(5) When the internal combustion forklift goes downhill, it is strictly prohibited to shut down and slide.
(6) It is forbidden to brake suddenly when the load is running except under special circumstances.
(7) When the load is driving over 7 degrees and the speed is higher than the first gear, the brake shall not be used except under special circumstances.
(8) When the forklift is running, it must abide by the traffic rules in the plant and keep a certain safe distance from the Feng vehicle in front.
(9) When the forklift is running, the load must be at the lowest position that does not hinder the driving. The gantry shall be tilted back properly. The load shall not be raised except when stacking or loading. When handling huge objects, the objects block the driver's line of sight. At this time, the forklift should be reversed.
(10) The steering of the forklift is controlled by the rear wheel, so we must always pay attention to the swing behind the forklift, so as to avoid the phenomenon of too fast turning that often occurs when beginners drive.
(11) It is forbidden to turn on the ramp or drive across the ramp.
(12) When the forklift is carrying goods downhill, it should travel backward to prevent the goods from falling.
（4） Loading and unloading
(1) When forking articles, the space between the two forks shall be adjusted as required to make the load of the two forks balanced without deflection. One side of the article shall be close to the shelf, and the weight of the fork shall comply with the provisions of the sign board of the load center curve.
(2) The height of the load shall not block the sight of the driver.
(3) During the loading and unloading of goods, the forklift must be braked with brakes.
(4) When the goods forklift approaches or evacuates the goods, the speed shall be slow and stable, and the wheels shall not crush the goods, wooden mats, etc., so as to avoid flying up and hurting people.
(5) When taking goods with a fork, the fork shall be forked under the load as far as possible, and it shall be noted that the fork tip shall not touch other goods or objects. The minimum gantry tilt back shall be used to stabilize the load to prevent the load from sliding backward. When placing the load, the gantry can tilt forward a small amount to facilitate the placement of the load and the extraction of the fork.
(6) It is forbidden to fork goods at high speed and collide with hard objects with fork head fou.
(7) During forklift operation, personnel are not allowed to stand on the fork.
(8) During forklift operation, personnel are not allowed to stand around the forks to avoid injury caused by the collapse of goods.
(9) It is forbidden to lift personnel at heights with a fork to avoid falling accidents.
(10) It is not allowed to use braking inertia to slip articles.
(11) It is not allowed to fork load the goods directly on the shore of the wharf.
(12) Single fork operation is prohibited.
(13) Overload operation is prohibited.
13. What are the safety technical conditions of forklift lifting mechanism?
Answer: (1) the gantry shall be free from deformation and weld desoldering. The rolling clearance of the inner and outer gantry shall be adjusted reasonably, which shall not be greater than 15mm. The rolling rotation shall be flexible, and the roller and shaft shall be free of cracks and defects. The wear amount of wheel groove shall not be greater than 10% of the original size.
(2) The tension of the two lifting chains shall be uniform without distortion, the ends shall be firmly connected, and the pitch of the chain shall not exceed 4% of the length, otherwise the chain shall be replaced. The sprocket shall rotate flexibly.
(3) The fork frame shall not be seriously deformed; The fork surface shall be free of cracks; The welds of all parts shall not be desoldered, the fork root angle shall not be greater than 93%, and the thickness shall not be less than 90% of the original size; The height difference between the left and right fork tips shall not exceed 3% of the length of the horizontal section of the fork; The positioning of the fork shall be reliable, and the supporting surface and positioning surface of the fork hook shall not have obvious defects; The clearance between the fork and the fork should not be too large.
(4) The connecting parts of the lifting oil cylinder and the gantry shall be firm, and the hinge of the tilt oil cylinder and the gantry and frame shall be firm and flexible, and the matching clearance shall not be too large. The oil cylinder shall be well sealed without cracks and work stably. Under the rated load, the self sinking amount of gantry in 10min shall not be greater than 20mm, and the inclination angle shall not be greater than 0.5 degrees. The lifting speed at full load shall not be less than half of the standard value.
14. What are the safety technical conditions of forklift hydraulic control system?
Answer: (1) the pipeline joints of the hydraulic system shall be firm without leakage, and shall not be worn with other parts. The rubber hose shall not be aged or deteriorated.
(2) The transmission components in the hydraulic control system shall not creep, stagnate and obvious impulse within the range of rated load and rated speed.
(3) The shell of multi-way directional valve shall be free of crack and leakage. Good and reliable working performance; The safety valve is sensitive and can be fully opened when it is overloaded by 25%. The nuts of adjusting bolts shall be complete and fastened. The operating handle shall be positioned accurately and reliably, and shall not be displaced due to vibration.
(4) Load curve and hydraulic control nameplate shall be complete and fresh.
15. Full hydraulic forklift
(1) The torque converter oil quantity needs to be marked by the dipstick. Add enough torque converter oil. No. 8 hydraulic liter transmission oil winter No. 22 Summer 30 turbine oil.
(2) The normal operating oil temperature of the torque converter is 90 degrees ± 10 degrees.
(3) When the oil temperature reaches 100 ℃, the vehicle needs to be stopped for cooling. So as not to affect the performance and service life of the vehicle.
(4) The torque converter gear pressure is 12 ± 1kg. Excessive pressure will affect the working performance and service life.
