Butterfly buckle leaf spring

Butterfly buckle leaf spring, also known as butterfly type fastener leaf spring, is a high-elastic metal elastic component widely used in truck cargo box sideboards, trailer doors, agricultural machinery covers, engineering equipment guard plates and logistics storage containers. Its name derives from the symmetrical butterfly-shaped buckle matching the leaf spring, which forms a quick-locking assembly with the spring steel strip. Different from ordinary flat leaf springs, this integrated buckle-spring structure combines fastening and elastic reset functions into one part, simplifying assembly procedures and greatly improving opening-closing efficiency of metal door panels. Made of high-quality spring steel with customized surface treatment, it delivers stable elastic tension, strong anti-fatigue performance and long service life under frequent vibration and repeated opening cycles.

Working Principle

The butterfly buckle leaf spring consists of two core parts: curved leaf spring strip and butterfly-shaped positioning buckle. When operators close the equipment door or cargo sideboard, the butterfly buckle clamps the leaf spring and compresses the arc spring strip to generate pre-tightening elastic force. The symmetrical butterfly buckle limits horizontal displacement of the spring, preventing loose separation caused by vehicle bumping during transportation. Once users lift the door panel, the stored elastic energy of the leaf spring releases instantly to provide automatic jacking and reset assistance, reducing manual pulling force. Even under long-distance bumpy driving, the buckle structure locks the spring tightly to avoid abnormal loosening, rattling or accidental door opening, effectively securing goods and equipment components.

Core Structural & Performance Advantages

Symmetrical butterfly buckle positioning design

The double-wing butterfly buckle fits the radian of the leaf spring perfectly, offering all-directional limiting. It avoids spring offset, slipping and falling off that often occur with single-point fasteners, adapting to high-vibration working conditions of trailers and heavy trucks.

High-strength spring steel raw material

The leaf spring body adopts 65Mn spring steel or stainless steel strip, processed through integral quenching and tempering treatment. It maintains stable elasticity after tens of thousands of opening-closing cycles, resisting permanent deformation and fatigue fracture.

Excellent environmental adaptability

Surface treatments include galvanization, powder coating and black oxidation, providing rust-proof, corrosion-proof and wear-resistant performance. It works stably in rainy, muddy, dusty and low-temperature outdoor environments without elastic attenuation.

Integrated dual-function design

It realizes locking and elastic reset in a single assembly, eliminating extra bolts, hinges and auxiliary springs. Manufacturers cut accessory costs and shorten production assembly time significantly.

Main Application Scenarios

This component is a standard fitting for light trucks, medium-duty cargo vehicles, flatbed trailers, refrigerated transport vehicles and dump trucks. It is also extensively equipped on agricultural machinery protective covers, construction machinery maintenance doors, storage box flip panels and logistics turnover containers. Two mainstream specifications are supplied: thickened heavy-load type for large trailer sideboards and thin lightweight type for small vehicle flip doors, customizable in spring length, arc radian and buckle size according to customer drawing requirements.

Maintenance & Service Features

Butterfly buckle leaf springs require almost no daily maintenance. Users only need to check the buckle clamping tightness and surface rust condition during regular vehicle inspection. Compared with traditional loose hinge springs, its failure rate drops sharply, lowering after-sales replacement costs for fleets and machinery manufacturers. For vehicle and equipment manufacturers, standardized batch supply, flexible customization and stable quality make this elastic fastener a cost-effective solution for flip door locking systems.