Equipment acceptance criteria (process version)
This standard serves as the core basis for equipment acceptance led by process personnel. It focuses on three major dimensions: equipment function matching, effectiveness of process error prevention, and parameter controllability, and clarifies the requirements for the entire process from setting to use.
I. Equipment settings: Define the "capability boundaries" and "error prevention logic"
The core of device settings is to define "what can be done", "what cannot be done", and "how to prevent doing things wrong". The following points need to be clarified one by one:
1. Function setting: Lock the core processing object and technical path
It is necessary to clarify the unique core processing object of the equipment (e.g., "used for processing precision metal shaft parts with a diameter of φ5 - φ50mm", "used for injection molding ABS plastic parts with a wall thickness of 0.5 - 5mm"), and the technical path for achieving the processing (e.g., "achieving multi - face processing through CNC milling", "achieving the curing of composite laminates through hot - press molding").
- Key point: Avoid "generalizing functions" – If the equipment is designed for "processing aluminum parts", it is necessary to clearly state that "it cannot process steel with a hardness of HRC
2. Equipment capacity setting: Identify the key attributes related to raw materials and processing
It is necessary to comprehensively identify the raw material attributes (dimensions, physical/chemical characteristics strongly related to the processing process) and product characteristics (performance indicators to be guaranteed after processing), and confirm whether these attributes are "fully covered".
- Examples of raw material attributes: Diameter tolerance of bar stock (e.g., ±0.05mm), thickness range of sheet metal (e.g., 1 - 3mm), melting point of heat-sensitive plastics (e.g., 180℃ ± 5℃), hardness of metals (e.g., HRC25 - 30);
- Examples of product characteristics: Dimensional tolerances of parts (e.g., ±0.02mm), surface roughness (e.g., Ra ≤ 0.8μm), and weld line strength of injection-molded parts (e.g., ≥20MPa).
- Verification requirement: It is necessary to check the "unrecognized attributes". If the "melting point of the raw material" is not recognized when processing thermosensitive plastics, it will lead to incorrect setting of the equipment temperature parameters, and the final product will shrink or char.
3. Error prevention at the input end: Automatic identification and interception of raw material attributes
For the properties of raw materials, special monitoring devices need to be configured, and the following requirements should be specified:
Device accuracy: For example, the accuracy of the laser sensor for dimension detection shall be ≥ ±0.01mm, and the accuracy of the portable hardness tester for hardness detection shall be ≥ ±1HRC.
Automatic detection ability: The device needs to be linked with a rejection/interception mechanism (for example, raw materials with out-of-tolerance dimensions automatically flow into the waste bin through the conveyor belt).
Data and Alarms: Data needs to be uploaded to the MES system in real-time (e.g., record the raw material dimensions once per second). When there is an out-of-tolerance situation, a hierarchical response will be triggered (e.g., "Alarm when the dimension tolerance exceeds ±0.02mm, and stop the machine immediately when the tolerance exceeds ±0.05mm").
Stability: The false alarm rate during continuous operation for 8 hours is ≤ 0.1% (if the laser sensor does not have false triggers caused by dust).
4. Error prevention during the processing (equipment parameters): Control the core equipment parameters that affect the product
It is necessary to identify all equipment parameters that affect product attributes (such as the spindle speed of CNC machines, the injection pressure of injection molding machines, and the temperature of thermoforming machines), and clarify the "parameter controllability":
Parameter identification: For example, when machining shaft parts, the "spindle speed" affects the surface roughness, and the "feed rate" affects the dimensional accuracy. All parameters need to be listed.
Detection and accuracy: The parameters shall be detectable in real - time through sensors (for example, use a rotation speed sensor to measure the spindle speed with an accuracy of ±5 rpm; use a pressure transmitter to measure the injection pressure with an accuracy of ±0.1 MPa).
Alarm and shutdown: When the parameters exceed the limit, a "hard shutdown" needs to be triggered (for example, when the injection pressure exceeds the set value by 10%, the hydraulic power source should be immediately cut off) to avoid batch scrap.
Data traceability: Parameters (such as the rotation speed and pressure curve for each batch of processing) need to be retained for more than one year for subsequent review of quality issues.
5. Positioning and error prevention in the processing process: Ensure that the parts "do not move and are not misaligned"
It is necessary to clarify whether positioning is required during the processing (for example, the part needs to be precisely positioned on the X/Y axis during drilling, and the part needs to be fixed to prevent rotation during milling), and the following requirements are put forward for the positioning fixture:
Fixture types: Special fixtures (suitable for products with stable batch production, such as CNC machining of mobile phone middle frames) need to clearly state "only compatible with a certain product model"; Universal fixtures (suitable for small-batch production of multiple varieties) need to clearly state "the compatible product size range" (e.g., "compatible with circular parts with a diameter of φ10 - φ30mm").
Adjustment convenience: The quick-change fixture shall meet the requirement of "completing product switching within 5 minutes" (for example, if a modular design is adopted, no recalibration is required).
Performance indicators: Positioning accuracy ≥ ±0.02mm (e.g., the positioning deviation after 100 consecutive clampings ≤ 0.01mm), stability ≥ 99.9% (e.g., the fixture has no deformation when subjected to cutting force), and the robustness should be able to withstand 1.2 times the rated cutting force (e.g., when the milling force is 1000N, the deformation of the fixture ≤ 0.01mm).
6. Error prevention at the output end: "Real-time detection and interception" of finished product attributes
It is necessary to clarify the detection attributes (such as dimensions, surface quality, mechanical properties) of the processed products and configure the corresponding detection devices.
- Examples of finished product attributes: Roundness of shaft parts (e.g., ≤0.005mm), warpage of injection-molded parts (e.g., ≤0.2mm), tensile strength of metal parts (e.g., ≥500MPa);
- Device requirements: The accuracy of the coordinate measuring machine should be ≥ ±0.003 mm, and the accuracy of the roughness meter should be ≥ ±0.01 μm.
- Response logic: When the finished product inspection shows an out-of-tolerance result, the processing of the next batch should be immediately suspended (for example, "if the roundness of 3 consecutive pieces is out of tolerance, the equipment will automatically stop and trigger the process personnel to conduct a recheck") to avoid batch waste.
7. Error prevention during the moving process: Control the "positional accuracy" of products/raw materials
If it is necessary to move products/raw materials during the processing (such as conveying parts by conveyor belts or handling semi-finished products by robotic arms), the following requirements need to be clarified:
Movement accuracy: The positioning accuracy of the conveyor belt is ≥±0.5mm (for example, when the parts need to stop accurately at the inspection station), and the repeat positioning accuracy of the robotic arm is ≥±0.05mm (for example, there should be no deviation when grabbing parts).
Stability: The part dropping rate after 1000 continuous movements ≤ 0.05% (for example, the friction force of the gripper of the robotic arm shall meet the requirement of "no slipping when grabbing a 5 kg part").
Error prevention linkage: The mobile device needs to be linked with the previous/subsequent equipment (for example, the processing equipment will not start when the conveyor belt fails to deliver the parts to the positioning point).
II. Supplementary settings: Solve the problems of "infeasible detection" and "sustainable maintenance"
For the "special scenarios" not covered in the settings, the following requirements need to be supplemented:
1. Feasibility assessment of direct detection
If the properties of raw materials/products cannot be directly detected (such as the internal stress of plastic parts and the fatigue life of metal parts), the following needs to be confirmed:
- Is there any indirect detection method as an alternative (e.g., using infrared thermal imaging to measure the surface temperature of plastic parts to indirectly infer internal stress; using ultrasonic flaw detection to detect internal defects in metal parts to indirectly evaluate fatigue life)?
- Accuracy deviation of alternative means (e.g., the correlation coefficient R² between temperature and stress ≥ 0.95, the defect detection rate of ultrasonic flaw detection ≥ 98%).
2. Maintenance requirements for error-proofing devices
It is necessary to clarify the inspection rules for error-proofing/mistake-proofing devices.
- Daily inspection: Clean the lens of the laser sensor before starting the machine every day (to prevent false alarms caused by dust), and check whether the positioning pins of the fixture are loose.
- Regular calibration: Calibrate the laser sensor with standard parts monthly (e.g., verify the dimensional detection accuracy with a φ10mm standard rod), and calibrate the pressure transmitter quarterly (verify the output value with a standard pressure source).
- Accountability: Clearly define that "the equipment operator is responsible for sensor calibration" and "the process engineer is responsible for verifying the positioning accuracy of fixtures".
3. Expandability of the detection device
It is necessary to confirm whether the equipment has reserved interfaces for detection devices (such as additional sensor installation positions and data interfaces for the MES system) to meet the needs of future product upgrades (for example, "currently detecting dimensions, when surface defect detection needs to be added in the future, a vision sensor can be directly installed").
III. Equipment acceptance documents: Clarify the "input-output" correspondence
During the acceptance process, the following documents need to be checked to ensure that "the equipment parameters correspond to the process requirements one by one":
1. List of overall dimensions: Match the workshop layout
The length, width, and height dimensions of the equipment (e.g., "2000mm × 1500mm × 2200mm") and installation requirements (e.g., "A maintenance space of 1000mm needs to be reserved", "The ground bearing capacity should be ≥ 5t/m²") need to be provided to ensure consistency with the workshop layout.
2. Equipment performance parameter table: Match product selection
It is necessary to provide the machining accuracy (e.g., "CNC milling accuracy ±0.005mm"), machining range (e.g., "maximum machining diameter 50mm, minimum machining diameter 5mm"), and machining capacity (e.g., "able to machine metals with hardness HRC ≤ 40"), and ensure they match the process requirements of the product.
3. Processing efficiency indicator: Match the production capacity planning
The processing volume per unit time (e.g., "Process 60 shaft parts per hour") and the man-hour per piece (e.g., "The man-hour for processing a φ20mm shaft is 8 minutes per piece") shall be provided to ensure consistency with the production capacity requirements (e.g., "500 pieces need to be produced daily").
4. Operation manual: Match the work instruction
A step-by-step operation process (e.g., "Preheat for 10 minutes before starting the machine. The main shaft can be started only after the oil temperature reaches 40°C") and safety operation specifications (e.g., "It is strictly prohibited to operate rotating parts while wearing gloves." "Turn off the hydraulic power source after shutdown.") shall be provided to ensure compliance with the requirements of the Standard Operating Procedure (SOP).
5. Parameter adjustment instructions: Match the job standard document
It is necessary to provide the corresponding relationship between equipment parameters and product parameters (e.g., "When machining a φ10mm hole, set the spindle speed to 1500rpm and the feed rate to 0.1mm/r") and adjustment rules (e.g., "When the hole diameter needs to be increased by 0.02mm, increase the feed rate by 0.005mm/r") to ensure that process personnel can quickly adjust the parameters.
6. List of error-proofing measures: Match the error-proofing management requirements
All error-proofing devices (such as "input laser size sensor", "process pressure transmitter", "output coordinate measuring machine"), their functions (such as "prevent unqualified raw materials from flowing in", "prevent equipment pressure from exceeding the tolerance", "prevent unqualified finished products from flowing out"), and maintenance responsibilities (such as "equipment technician checks the cleanliness of the sensor weekly", "process technician calibrates the coordinate measuring machine monthly") need to be listed.
7. Failure Mode and Effects Analysis (FMEA): Match risk management and control
A list of equipment failure modes (e.g., "Raw materials flow in with out-of-tolerance due to laser sensor failure", "Machining accuracy decreases due to spindle bearing wear"), failure impacts (e.g., "Batch products are scrapped", "Equipment stops for 8 hours"), and control measures (e.g., "Check the sensor status weekly", "Replace the bearings every 5000 hours") shall be provided.
8. Danger warning: Match safety management
It is necessary to list the equipment's dangerous points (e.g., "Spindle rotation area - Prone to clothing entanglement", "Heating chamber - High - temperature scalding"), warning methods (e.g., "Red warning light + Buzzer", "Safety light curtain + Emergency stop button"), and protective measures (e.g., "Install a spindle protective cover", "Equip the heating chamber with an insulated door"), and ensure consistency with the safety signs in the workshop.
9. Upgrade and improvement ability: Match future needs
It is necessary to confirm whether the equipment has reserved expansion space (such as "extra sensor installation interfaces", "20% redundancy in motor power", "a 1m² expansion workstation reserved beside the equipment") to ensure that there is no need to "tear down and rebuild" when upgrading the product in the future.
IV. Equipment use: Clearly define "maintenance requirements" and "parameter limits"
After the equipment acceptance is passed, it is necessary to clarify to the user department "how to use it correctly" and "how to maintain it" to avoid equipment failures or product quality problems caused by improper operation.
1. Management of vulnerable parts: Define "impact and replacement cycle"
It is necessary to identify vulnerable parts (such as CNC cutting tools, barrels of injection molding machines, and rollers of conveyor belts) and clarify:
- The influence of vulnerable parts on the product (e.g., "Tool wear can cause the surface roughness to exceed the tolerance" and "Barrel wear can cause black spots on injection-molded parts");
- Replacement cycle (e.g., "Replace the cutting tool after processing 1000 pieces", "Clean the barrel after producing 5000 pieces").
2. Management of consumable parts: Define "lifespan and impact"
It is necessary to identify the consumable parts (such as bearings, seals, hydraulic oil) and clarify:
- The service life of consumable parts (e.g., "Replace the bearing after 5000 hours of operation", "Replace the hydraulic oil once every 6 months");
- The impact of consumable parts on the product (e.g., "Bearing wear will cause fluctuations in the spindle speed, affecting the machining accuracy." "Deterioration of hydraulic oil will lead to unstable pressure, resulting in flash on injection molded parts.").
3. Optimal working parameters: Define the "balance between efficiency and lifespan"
The normal standard operating parameters of the equipment (i.e., the "optimal operating point") need to be provided, such as "the optimal rotation speed of the CNC is 2000 rpm and the feed rate is 0.15 mm/r", "the optimal pressure of the injection molding machine is 120 bar and the temperature is 190°C". These parameters represent the balance point between product quality and equipment lifespan (an excessively high rotation speed will shorten the tool life, while an excessively low one will reduce efficiency).
4. Requirements for auxiliary materials and auxiliary facilities: Define the "qualifying conditions"
It is necessary to clarify the requirements of the equipment for auxiliary materials (such as cutting fluids, release agents, lubricants) (e.g., "The cutting fluid shall be a synthetic cutting fluid with a viscosity grade of ISO VG 22", "The release agent shall be food-grade silicone oil"), as well as the requirements for auxiliary facilities (e.g., "The compressed air pressure shall be ≥ 0.6 MPa", "The cooling water temperature shall be ≤ 25 °C", "The power supply voltage fluctuation shall be ≤ ± 5%").
5. Environmental impact: Define the "scope of application"
It is necessary to clarify the environmental requirements of the equipment.
- Temperature: For example, "The optimal operating temperature is 18 - 25°C. Exceeding 30°C will cause malfunctions of electronic components."
- Humidity: For example, Relative humidity ≤ 60%, prevent electrical components from rusting.
- Vibration: For example, "The ground vibration acceleration ≤ 0.1g to avoid the decline of machining accuracy";
- Verification requirements: At the time of acceptance, a thermohygrometer and a vibration sensor shall be used to test the on - site environment. If the environment does not meet the requirements, rectification shall be carried out (e.g., installing an air - conditioner and performing vibration - damping treatment on the ground).
Instructions
This standard focuses on "the matching of process requirements and equipment capabilities", and all requirements are designed around "ensuring product quality and avoiding process risks". Process personnel need to check item by item during acceptance to ensure that the equipment "can meet the current process requirements and has the ability for future expansion".