Engineering machinery and equipment quality appraisal

engineering machinery equipment is based on the core principle of power transmission and operation efficiency synergy. By optimizing engine power, hydraulic system pressure and structural strength, it achieves the synergy of efficiency, safety and durability in excavation, lifting, transportation and other operations. It is widely used in construction, mining, port logistics and municipal engineering and other fields. In earthmoving engineering, it is used for the multi-working condition adaptability of hydraulic excavators; in high-altitude operations, it meets the precise positioning requirements of boom cranes; in heavy-duty transportation, it ensures the impact resistance of mining trucks. Compared with general equipment, construction machinery equipment has the characteristics of intelligent control, modular maintenance and environmental compliance (National IV/Euro V emission standards), etc., and is the core equipment of modern engineering construction.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide quality appraisal services for engineering machinery and equipment. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for the quality appraisal of engineering machinery and equipment.

With the large-scale development of engineering projects, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: insufficient actual output power, low efficiency of the hydraulic system;

2, material defects: fatigue life of engine crankshaft, welding cracks in structural parts;

3, process problems: pulse pressure fluctuations in hydraulic pipelines, sensor calibration deviations;

4, contract performance disputes: core modules (such as imported hydraulic pumps, intelligent control system versions) are inconsistent with the technical agreement.

Based on the characteristics of construction machinery and equipment, common quality identification technical methods include:

1, equipment performance testing

to detect various performance indicators of non-standard construction machinery and equipment, including operating speed, power, torque, accuracy, etc. Through actual testing, evaluate whether the equipment meets the requirements of the technical contract.

2, material quality analysis

analyzes the physical properties, chemical properties, microstructure, etc. of the material to determine the quality status of the material. For example, metallographic analysis can be used to understand the structural structure of steel and determine whether there are defects.

A construction company of the applicant signed a "50-ton excavator purchase contract" with a manufacturer of the defendant, agreeing that the excavation force is ≥180kN. The hydraulic system frequently lost pressure during use, and the manufacturer argued that it was caused by improper operation.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of "engineering machinery and equipment", contract technical agreements, on-site inspection case materials and other data, and made the following quality analysis Opinion:

The volumetric efficiency of the hydraulic pump of the engineering machinery involved in the case is only 75% (agreement ≥85%), the main valve core wear amount is 0.15mm (agreement ≤0.05mm); the Cr content of the engine crankshaft is only 0.8% (agreement 1.0-1.5%), and the fatigue life is only 60% of the agreement value.

The appraisal concluded that defects in the hydraulic system and materials were the main causes of insufficient performance.

Construction machinery equipment quality appraisal report should include:

1, purpose of appraisal (such as attribution of work accidents, performance verification) and reference standards;

2, model of equipment involved, technical agreement, maintenance records;

3, testing method and equipment list ( Such as torque sensor, SEM);

4, detection data and failure correlation analysis (such as the impact of hydraulic efficiency on excavation force);