Guidelines for Quality Assessment of Electric Forklifts (Latest Version in 2025)

1、 Core evaluation standards and specifications

1.1 Industry standard basis

Group Standard for Battery Forward Moving Forklifts (T/ZZB 000-2020):

New security requirements have been added for operation permission collection (fingerprint/password recognition) and turning speed limit (≤ 7km/h).

When the lifting height is ≥ 6.5 meters, it is mandatory to install a real-time video assistance system.

Electromagnetic compatibility complies with ISO 13766:2018 standard, and the operating noise is ≤ 75dB.

GB/T 27544-2011 "Electric Forward Moving Forklifts":

Specify the stiffness test of the gantry (deformation less than 5% at 1.33 times the rated load).

The average time between failures in bench testing is ≥ 300 hours.

1.2 Key Performance Indicators

Core indicators of evaluation dimensions

Power system battery capacity decay rate (≤ 20%/year), motor efficiency (≥ 90%), range error (≤ 5%)

Hydraulic system lifting speed (≥ 0.5m/s), gantry sinking (≤ 0.3% full stroke), hydraulic oil temperature rise (≤ 45K)

Emergency braking distance of safety device (≤ 3m), speed limiter accuracy (± 1km/h), protection level (IP54)

Human engineering operation field of view (lateral ≥ 120 °), vibration acceleration (≤ 2.5m/s ²), noise (≤ 75dB)

2、 Quality inspection methods for key components

2.1 Battery system testing

Capacity test: Charge and discharge at 1C rate according to GB/T 31486-2022, and record the deviation between the actual capacity and the nominal value (≤ 8%).

Life assessment: Simulate full load cycle testing and record the number of cycles (≥ 800) when the capacity decays to 80%.

Safety verification: After short-circuit testing (current ≥ 300A), there is no explosion or fire phenomenon.

2.2 Motor and control system testing

Efficiency test: Measure input/output power at rated load and calculate efficiency (≥ 92%).

Overload capacity: Short term overload of 150% rated torque for 30 seconds without abnormal heating or mechanical damage.

Fault diagnosis: Simulate sensor failure and verify the accuracy of control system alarm (≥ 98%).

2.3 Hydraulic system testing

Sealing test: Apply pressure to 1.5 times the working pressure and hold for 30 minutes, with a leakage rate of ≤ 2 drops/minute.

Stability of lifting and leveling: Load fluctuation test (± 20% rated load), fork height fluctuation ≤ 5mm.

Emergency function: Simulate power outage and verify the effectiveness of the manual descent device (complete descent within ≤ 5 minutes).

2.4 Structural and safety component testing

Door frame strength: Apply 1.5 times the rated load, and the deformation after 1 hour of static load is ≤ 0.2% of the full stroke.

Braking performance: Emergency braking on wet and slippery road surfaces (μ=0.15), with directional stability deviation ≤ 0.5m.

Protective device: After collision testing (8km/h), the integrity of the cab structure is retained by ≥ 85%.

3、 Common quality issues and solutions

3.1 Hydraulic system malfunction

Phenomenon: Slow lifting speed and shaking of forks.

Reason: Hydraulic oil contamination (particulate matter>10 μ m), oil pump wear (clearance>0.1mm).

Solution:

Replace the hydraulic oil and install a three-stage filtration device (filtration accuracy ≤ 5 μ m).

Repair or replace the oil pump, adjust the axial clearance to 0.05-0.08mm.

3.2 Electrical System Abnormalities

Phenomenon: The battery is not fully charged and the controller is malfunctioning.

Reason: charger voltage drift (>± 1%), line contact resistance>50m Ω.

Solution:

Calibrate the charger output voltage (accuracy ± 0.5%).

Replace silver plated terminal blocks and use conductive paste to reduce contact resistance.

3.3 Steering system issues

Phenomenon: Heavy direction and insensitive steering.

Reason: Internal leakage of steering cylinder (pressure attenuation>20%), wear of steering gear (tooth thickness reduction>15%).

Solution:

Replace the oil cylinder seal with polyurethane material.

Repair or replace the steering gear, adjust the gear backlash to 0.1-0.2mm.

3.4 Abnormal Drive System

Phenomenon: Weak driving and wheel hub oil spillage.

Reason: demagnetization of motor magnet (residual magnetization<0.8T), poor lubrication of bearings (temperature rise>45 ℃).

Solution:

Replace the neodymium iron boron magnetic steel and re magnetize it to 1.2T.

Clean the bearings and replace the lithium based grease (NLGI grade 2).

4、 Quality improvement technology plan

4.1 Intelligent monitoring system

Deployment plan:

Install a three-axis acceleration sensor (range ± 5g) to monitor the vibration of the gantry.

Use an infrared thermal imager (resolution 640 × 480) to detect the temperature field of the motor.

Data platform:

Real time upload to the cloud to generate fault prediction models (accuracy ≥ 90%).

When the hydraulic oil temperature exceeds 70 ℃ or the motor temperature exceeds 120 ℃, an alarm is triggered.

4.2 Modular Maintenance Design

Control system:

Adopting CAN bus architecture, supporting hot plugging and replacement of faulty modules.

Develop diagnostic software that can read fault codes and modify parameters (such as driving speed).

Hydraulic system:

Design quick change connectors, hydraulic pipeline replacement time ≤ 15 minutes.

Integrated filtration cooling device, extending the hydraulic oil replacement cycle to 2000 hours.

4.3 Environmental Protection and Safety Upgrades

Battery system:

Using lithium iron phosphate batteries, it has passed the UN 38.3 transportation safety test.

Configure BMS system to achieve SOC accuracy error ≤ 5%.

Noise control:

Optimize the design of motor cooling fan blades to reduce aerodynamic noise (sound pressure level<70dB).

Install sound-absorbing cotton (thickness 20mm, density 32kg/m ³) in the cab.

5、 Typical Case Analysis

5.1 Optimization of hydraulic system for forklift in an e-commerce warehouse

Problem: The hydraulic oil temperature rises too quickly (up to 85 ℃) under high temperatures in summer, leading to aging and leakage of seals.

Solution:

Replace the high-temperature resistant hydraulic oil (VG68) and install an oil cooler (flow rate 20L/min).

Effect: The oil temperature remains stable below 65 ℃, and the lifespan of the seal is extended to 12 months.

5.2 Electrical system upgrade of a manufacturing enterprise

Problem: The battery charging efficiency is low (only 85%), which affects work efficiency.

Solution:

Upgrade the charger to a pulse repair type and optimize the charging curve (constant current constant voltage float charging).

Effect: Charging efficiency increased to 92%, and single charging operation time increased by 1.5 hours.

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