Solution to Defects in Support Points of Electric Forklifts

1、 Structural design optimization

1.1 Improvement of Supporting Structure

Patent technology reference: Adopting a front axle support structure, the outer door frame is connected through a bushing to prevent the door frame from moving in the width direction (refer to patent CN 113057977 B).

Finite element analysis: Use ANSYS Workbench for stress analysis, optimize hazardous sections, reduce weight while ensuring strength (such as the weight reduction of 11.5% in the fork frame optimization case).

1.2 Key component design

Door frame system:

The outer door frame is made of high-strength steel and the cross-sectional shape is optimized to be U-shaped or C-shaped to enhance its bending resistance.

Add guide rollers at the joint between the inner and outer door frames to reduce friction and wear.

Wheel support:

The front wheels adopt a dual wheel design, which disperses the load and reduces single point pressure.

Add a stabilizer bar structure to the rear wheels to prevent tilting.

2、 Material selection and processing

2.1 Material Upgrade

Main structure:

The frame and door frame are made of Q345B low-alloy high-strength steel, with a yield strength of ≥ 345MPa.

The fork arm is made of 6061-T6 aluminum alloy, which reduces weight by 30% while maintaining load-bearing capacity.

Sealing element:

Adopting Zurcon from Trelleborg company ®  U-cup and HiMod ®  Slydring ®， Wear resistant and high temperature resistant (-40~150 ℃).

2.2 Surface Treatment

Rust prevention treatment:

The pre-treatment of metal components meets the Sa2.5 sandblasting standard.

Coating system: two-component epoxy primer (80-100 μ m)+polyurethane topcoat (60-80 μ m).

Key joint surface: Apply Vaseline or Molykote DX anti rust grease.

3、 Manufacturing process improvement

3.1 Welding process

Weld quality control:

The key weld seam adopts CO ₂ gas shielded welding, and the weld height is not less than 80% of the base metal thickness.

Perform 100% ultrasonic testing after welding to ensure no cracks or pores.

Stress relief: Perform stress relief annealing treatment after welding (temperature 550~600 ℃, insulation for 2 hours).

3.2 Precision machining

Coordination accuracy:

The flatness of the mating surface between the gantry and the frame is ≤ 0.2mm.

The tolerance of the mating aperture between the fork arm and the fork is controlled at H7 level.

Surface roughness: The sliding surface roughness Ra is ≤ 1.6 μ m, reducing friction.

4、 Maintenance and upkeep standards

4.1 Daily Inspection

Inspection items:

Tightening torque of support point bolts (such as door frame connecting bolts: M16 × 1.5, torque 180~200N · m).

The gap between the fork arm and the door frame (normal value ≤ 2mm).

Roller wear amount (diameter wear ≤ 10%).

Frequency: Daily pre homework inspection, monthly in-depth inspection.

4.2 Preventive Maintenance

Lubrication plan:

Apply lithium based grease (NLGI grade 2) to the guide rails of the gantry every 500 hours.

Lubricate the chain every 200 hours using EP2 lubricating oil.

Component replacement:

Replace the roller after running for 2000 hours.

Replace the liner when the wear amount is ≥ 2mm.

4.3 Operating Standards

Load control:

Overloading is prohibited (rated load ± 5%).

Adjust the fork spacing to the load width+50mm.

Driving standards:

Slope gradient ≤ 15% (longitudinal), sharp turns are prohibited.

Ground bearing capacity ≥ 15MPa (concrete ground).

5、 Environmental control

5.1 Warehouse Environment

Temperature and humidity control:

Relative humidity ≤ 75%, install dehumidifier (daily dehumidification capacity ≥ 50L).

The temperature range is 5-40 ℃ to avoid material deformation caused by extreme temperatures.

Cleaning management:

Clean the ground daily to prevent sand and gravel from entering the support points.

Install drainage ditches in the forklift parking area to prevent water accumulation and corrosion.

5.2 Working environment

Channel design:

Channel width ≥ gantry width+1m (balanced weight forklift).

Reserve a turning radius of 1.5 times the length of the vehicle body.

Lighting requirements: The illumination in the work area should be ≥ 300lux to ensure clear visibility.

6、 Technological upgrade

6.1 Intelligent Monitoring

Sensor deployment:

Install strain gauge sensors to monitor support point stress (sampling frequency 100Hz).

The temperature sensor monitors the temperature of key components (warning threshold 80 ℃).

Data platform:

Upload data in real-time to the cloud and generate corrosion rate curves (historical data retained for ≥ 3 years).

When the corrosion rate exceeds 0.1mm/year, a Level 3 alarm is triggered.

6.2 Automatic Maintenance System

Automatic lubrication:

Install an electric lubrication pump on the guide rail of the gantry, and automatically inject grease according to the mileage.

The chain lubrication adopts a central lubrication system, which automatically supplies oil every 200 hours.

Fault diagnosis:

Integrate AI algorithms to identify support point looseness through vibration signals (accuracy ≥ 95%).

Quick Reference Table for Fault Codes (e.g. E05: Controller Overheating → Shutdown Cooling for 30 Minutes).

7、 Case verification

7.1 Application Case of a Logistics Center

Problem: Forklift support points frequently break, with an average annual failure rate of 12%.

Solution:

The frame material has been upgraded to Q345B, and the door frame section has been optimized to be U-shaped.

Install stress sensors to monitor and adjust loads in real-time.

Effect: The failure rate has been reduced to 3%, and maintenance costs have been lowered by 40%.

7.2 Optimization Case of a Manufacturing Factory

Problem: Corrosion at the support point causes the gantry to tilt.

Solution:

The surface treatment has been upgraded to an epoxy+polyurethane coating system.

Add temperature and humidity sensors to automatically activate dehumidification.

Effect: The corrosion rate has been reduced from 0.2mm/year to 0.05mm/year, and the service life has been extended to 10 years.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment