Bending of Office Chair Brackets

The bending of office chair brackets is closely related to materials, design, and testing. The bending characteristics and handling methods for different types of brackets are as follows:

Bending Design of Bow-shaped Chair Brackets

The core structure of a bow-shaped chair consists of a metal bracket formed by bending thickened steel tubes to create a stable arc-shaped support. The bending process must meet two requirements:

• Structural Stability: The arc design must ensure a reasonable center of gravity distribution through mechanical calculations to prevent the chair from tipping over due to bracket deformation. The bending radius of the thickened steel tubes must comply with the material's ductility limit to prevent cracks or fractures during processing.
• Noise Reduction and Balance: Since bow-shaped chairs do not require wheels, the bent brackets must form a uniform contact surface with the ground to reduce localized pressure concentration. The bending angle is typically controlled between 120° and 150° to balance the support force and comfort during human sitting postures.

Bending Durability Testing of Armrest Brackets

The bending performance of office chair armrest brackets must undergo rigorous testing using specialized equipment:

• Testing Equipment Principle: The armrest fatigue and alternating bending durability tester applies high-frequency alternating cyclic loading (e.g., 15-30 times per minute) to simulate human leaning and lateral pressure actions, focusing on testing the metal bracket's bending toughness, fatigue resistance, and loosening of connecting components.
• Testing Standards: The equipment must accommodate different types of armrests (e.g., fixed, adjustable, and flip-up types), with a typical testing cycle of 50,000 to 100,000 cycles. If cracks appear, deformation exceeds 2mm, or connecting components loosen during testing, the bracket is deemed unqualified.

Bending Processing Characteristics of Cold-drawn Seamless Alloy Steel Tubes

High-end office chairs (e.g., ergonomic chairs) often use cold-drawn seamless alloy steel tubes as the support frame for the backrest or seat surface. The bending process must meet the following conditions:

• Material Characteristics: The cold-drawing process endows the steel tubes with high-precision dimensions (tolerance ±0.1mm) and high strength (tensile strength ≥600MPa) while retaining some elasticity, allowing them to be bent into streamlined brackets that conform to the human spine's curve.
• Processing Limitations: The bending radius must be greater than twice the diameter of the steel tube; otherwise, the tube wall may become thinner or rupture. After processing, stress-relief annealing treatment (temperature 200-300°C, holding for 1-2 hours) must be performed to eliminate internal stresses and prevent deformation during long-term use.

If abnormal bending occurs in office chair brackets, the cause must be identified based on the bracket type: for bow-shaped chairs, it may be due to insufficient tube thickness or bending process defects; for armrest brackets, it may be due to poor material toughness or failure to meet testing standards; for cold-drawn steel tube brackets, it may be due to exceeding processing parameters or failure to perform stress relief. It is recommended to contact the manufacturer to test material properties and processing techniques and replace the brackets with qualified ones if necessary.