Pneumatic pick quality appraisal

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pneumatic pick machine uses compressed air to drive the piston and high-frequency impact as its core principle. It transmits the impact force through the drill rod to achieve crushing operations of brittle materials such as rocks and concrete. It is widely used in mining, tunnel construction, road maintenance and other fields. In the mining industry, it is used for tunnel excavation; in the construction and demolition field, it is responsible for the rapid demolition of reinforced concrete structures; in municipal engineering, it is used to complete the crushing and renovation of old road surfaces. Compared with electric breaking tools, pneumatic picks have the characteristics of explosion-proof safety, no dependence on power supply, and high impact frequency, and are the preferred equipment under special working conditions.

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

As infrastructure construction accelerates, the number of quality disputes involving pneumatic pick machines has gradually increased. The judicial dispute focuses on:

1. Disputes over performance indicators: whether the impact energy reaches the standard and whether the impact frequency meets the design value;

2. Material defects: the cylinder material has insufficient wear resistance and the drill rod’s resistance to Insufficient fatigue strength;

3. Process problems: The clearance between the piston and the cylinder is out of tolerance, and improper heat treatment process control leads to fracture;

4. Contract performance issues: The delivered equipment does not match the technical agreement.

0In such cases, the quality appraisal of the pneumatic pick machine needs to be combined with impact performance testing, material failure analysis and dynamic response evaluation to provide technical support for the court to determine the attribution of liability.

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The quality appraisal of the pneumatic pick generally includes the following technical methods:

1. Appearance inspection: Check whether the appearance of the pneumatic pick has defects such as deformation, cracks, corrosion, etc.

2. Performance test: Use special equipment to test the performance indicators such as the hitting frequency, hitting force, and air consumption of the pneumatic pick.

3. Disassembly inspection: disassemble the pneumatic pick for internal inspection to evaluate the machining accuracy, assembly quality and wear degree of the parts.

4. Material analysis: Carry out material analysis on the key parts of the pneumatic pick (such as bit, cylinder) to confirm whether the materials meet the standard requirements.

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A mining company of the applicant signed a "Pneumatic Pickaxe Machine Purchase Contract" with a machinery company of the respondent, agreeing to purchase 50 Typhoon Pickaxe Machines for underground mining. During use, the breakage rate of the drill rod exceeds 20%, resulting in a 40% decrease in excavation efficiency. The mining company believed that the equipment had quality defects and demanded compensation for losses. The machinery company argued that the problem was caused by improper operation, and both parties went to court.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "wind pick", contract technical agreement, on-site investigation case materials and other data, and made the following quality analysis opinions:

The pole material of the wind pick involved in the case is 45 steel (the contract requires 35CrMo), and the Cr content is only 0.3%, the hardenability is insufficient; the thickness of the chromium plating layer on the piston surface is only 5μm (standard ≥10μm), and the wear resistance is insufficient. The matching gap between the cylinder and the piston reaches 0.15mm (standard ≤ 0.08mm), resulting in loss of impact energy; the heat treatment process is not implemented according to the standard, and the hardness of the drill rod is only HRC35 (standard ≥ HRC45).

Machinery Company failed to provide drill rods and pistons of specified materials according to the contract, and the control of process parameters was not up to standard, which was the main reason for equipment problems.

The wind pick quality appraisal report should include the following content:

1. The purpose and basis of the appraisal.

2. Model, specification, manufacturer and other information of the equipment being identified.

3. Identification method.

4. Identification results (including whether there are quality problems, causes of problems, etc.).

05. Identification conclusion.

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26. Signature and seal of the appraiser, and official seal of the appraisal institution.

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