This standard is applicable to reciprocating piston internal combustion engines with a power of less than 1000 horsepower. This standard specifies the method for determining the cleanliness of internal combustion engine parts, assemblies and complete machines. GB/T 3821-1983 Method for determining the cleanliness of small and medium power internal combustion engines GB/T3821-1983 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of cleanliness for small and medium power internal combustion engines This standard applies to reciprocating piston internal combustion engines with a power of less than 1000 horsepower. UDC 621.431
GB 3821-—83
This standard specifies the method for determining the cleanliness of parts, assemblies and complete machines of internal combustion engines. When determining the cleanliness of parts and assemblies, the main engine manufacturer shall draw on the assembly line. 1 Measurement items and parts
1.1 Parts
The measurement parts of parts shall comply with the provisions of Table 1. Table 1
1.2 Assembly
Cylinder head
Camshaft
Rocker shaft
Intake (manifold)
All inner surfaces (except water channels), including air channels, oil channels and all inner surfaces of combustion chamber (except water channels), including all surfaces of air channels, oil channels (except flanges) and oil channels
All surfaces and oil channels
All surfaces and oil channels
Intake channel
The measured parts after disassembly of the assembly shall comply with the provisions of Table 2. Table 2
Piston connecting rod assembly
Carburetor assembly
Fuel injection pump assembly
Oil pump assembly
Fuel injector assembly
Oil coarse filter and fine filter assembly
Air compressor assembly
Oil radiator (cooler)
Note: Press fittings and connectors that are not suitable for disassembly are not disassembled. 1.3 Complete machine
The measurement items and parts of the complete machine shall comply with the provisions of Table 3. Issued by the National Bureau of Standards on August 9, 1983
All surfaces and channels (not disassembled)
All parts surfaces (except the outer surface of the assembly)All parts surfaces (except the outer surface of the assembly)All parts surfaces (except the outer surface of the assembly)All parts surfaces (except the outer surface of the assembly)All parts surfaces (except the outer surface of the assembly)Inner surface and oil channel of crankcase
Implemented on May 1, 1984
Oil pan
Oil coarse filter assembly
Oil fine filter assembly
GB 3821—83
Inner surface (including magnetic plug surface)
All parts surface (except assembly outer surface) All parts surface (except assembly outer surface) Position
All engine oil [including oil pan, engine oil coarse and fine filter and engine oil radiator (cooler)] Note: When two-stroke small gasoline engine and other special cases or internal combustion engines with other provisions need to be disassembled for measurement, refer to the Appendix (reference part). 2 Measuring instruments and cleaning fluidbZxz.net
2.1 Filter element
2.1.1 Filter membrane: 5 micron microporous filter membrane (the difference between two drying and weighing is not more than 0.4 mg). 2.1.2 Filter screen: mesh number 00385.
2.2 Cleaning fluid: NY-120, which should comply with the provisions of GB1922-80 "Solvent Oil". 2.3 Apparatus and equipment
Nylon round brushes, flat brushes and paintbrushes of various sizes. Washing bottles and syringes.
Containers such as basins and buckets with lids of different sizes. Magnets.
Tweezers with flat and toothless ends.
The whole machine and heavier parts should be equipped with a special rotating cleaning device. Analytical balance with a sensitivity of 1 part per ten thousand.
Vacuum pump (vacuum degree not greater than 600 mmHg) and membrane filtration device (see schematic diagram). Funnel
Funnel seat
Rubber stopper
Suction bottle
2.3.9Oven, dryer and weighing bottle.
Schematic diagram of membrane filtration device
2.3.10Microscope with scale, its magnification is greater than 40 times. 3 Operating procedures for impurity collection
3.1 Preparation
Metal clamp
3.1.1 Cleanliness determination should be carried out in a clean, well-ventilated room with safety measures. 93
GB 3821—83
3.1.2 Operators should wear clean clothes, hats and shoes, and wash their hands. 3.1.3 Non-determination parts of parts, assemblies and complete machines should be cleaned. All sampling tools, brackets and containers should be cleaned thoroughly. 3.1.4
3.1.5 The cleaning fluid used should be filtered through a filter membrane with an accuracy of about 10 times higher. 3.1.6 Preparation of filter elements.
3.1.6.1 Place the filter flat in the cleaning solution and soak for 10 minutes, then take it out. After the cleaning solution evaporates, place it in a 105±5℃ oven, take it out after 60 minutes, place it in a desiccator to cool for 30 minutes, and weigh it for later use. 3.1.6.2 Use tweezers to place the filter membrane in a weighing bottle, half-open the cover and place it in an oven that has been heated to 90±5℃. After 60 minutes, take it out, place it in a desiccator to cool for 30 minutes, and weigh it for later use. (If needed, multiple filter membranes can be dried and weighed together, but no more than 3 filters can be placed in each weighing bottle, and the filter membranes are required to be staggered). The difference between the two drying and weighing of the filter membrane is required to be no more than 0.4 mg. 3.2 Operation steps
3.2.1 Parts
3.2.1.1 When cleaning the surface, dip a flat brush into the cleaning solution and use it with a syringe or washing bottle to repeatedly rinse all the measurement parts.
3.2.1.2 When cleaning various channels, use a cylindrical brush or syringe that is larger than the aperture to clean. After flushing the blocked holes, use a magnet to suck out the iron filings at the bottom, remove other impurities, and then rinse them clean. 3.2.1.3 When flushing with various instruments, prevent the cleaning liquid with impurities from splashing outside the container, and collect all cleaning liquid with impurities.
3.2.2 Assembly
After the assembly is disassembled, clean and collect the cleaning liquid with impurities according to the provisions of 3.2.1.1 to 3.2.1.3. 3.2.3 Complete machine
3.2.3.1 For the complete machine with anti-rust oil, whether the anti-rust oil should be cleaned or replaced before use can be handled according to the requirements of the manual. According to the provisions of the product manual, when adding engine oil, its mechanical impurities should meet the requirements of GB485-81 "Gasoline Engine Lubricating Oil" and SY1152-77 "Diesel Engine Lubricating Oil". After the engine oil temperature reaches 65°C after more than 30 minutes of hot running, the engine oil can be measured (a two-stroke small gasoline engine can be measured after more than 30 minutes of hot running). 3.2.3.2 Collect all the engine oil in the oil pan, the coarse and fine oil filters and the oil radiator (cooler). 3.2.3.3 Remove the coarse and fine oil filter covers, take out the filter element and disassemble it (except when it is not suitable to disassemble it), and then immerse it in a container containing cleaning liquid for washing. And rinse the inner surface of the shell.
3.2.3.4 Clean the inner surface of the oil pan, including the surface of the magnetic screw plug. 3.2.3.5 Collect the cleaning liquid with impurities separately. Filtration and weighing of impurities
4.1 Filtration
4.1.1 The cleaning liquid with impurities collected from parts and assemblies is vacuum filtered with a filter membrane. 4.1.2 The cleaning fluid and all the engine oil collected from the whole machine with impurities can be filtered with a filter membrane or filter screen. (Each industry can make specific regulations on the use of filter membranes or filter screens based on the characteristics of the internal combustion engine and the requirements of use). 4.2 Weighing
4.2.1 For the filter screen with impurities, use the cleaning fluid to clean the engine oil on the filter screen. After the cleaning fluid evaporates, put the filter screen together with the impurities into the original weighing bottle and weigh it according to the provisions of 3.1.6.1. 4.2.2 For the filter membrane with impurities, use the cleaning fluid to clean the engine oil on the filter membrane. After the cleaning fluid evaporates, put the filter membrane together with the impurities into the original weighing bottle and weigh it according to the provisions of 3.1.6.2. 5 Calculation and recording of impurities
5.1 The weight of impurities is calculated as follows:
W=G1-G2
The weight of the filter screen or filter membrane before filtration, mg, GI-The weight of the filter screen or filter membrane after filtration, mg, W
The weight of impurities, mg.
Use a magnet wrapped in cellophane to separate the iron filings in the impurities and weigh the weight of iron (mg). Use a microscope with a magnification of more than 40 times to measure the size of the largest particle (length × width). Record the measurement results according to Table 4.
Cleanliness measurement data record
Product name and model
Measurement items and locations
Engine oil brand
Impurity weight (mg)
Iron weight in impurities (mg)
Maximum particle size
Length × width
(micrometer)
Foreign materials in impurities
Filter element
Measurement date
Measurer
GB 3821—83
Appendix A
(reference)
When the cleanliness of the whole internal combustion engine is disassembled for measurement, the names of parts and assemblies and the locations where impurities are collected are shown in the table below. Serial number
Additional instructions:
Oil pan
Oil coarse filter assembly
Oil fine filter assembly
Cylinder head
Camshaft
Piston connecting rod assembly
Inner surface (including magnetic screw plug surface)
All parts surfaces (except assembly outer surface) All parts surfaces (except assembly outer surface) Position
All engine oil [including oil in oil pan, oil coarse and fine filters, oil radiator (cooler)]
All inner surfaces (except water channels), including air channels, oil channels and all inner surfaces of combustion chambers (except water channels), including all surfaces of air channels, oil channels (except flanges) and oil channels
All surfaces and oil channels
All surfaces and channels (without disassembly)
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of Shanghai Internal Combustion Engine Research Institute. This standard was jointly drafted by Shanghai No. 1 Mechanical and Electrical Bureau Technology Information Institute, Second Automobile Works, and Beijing Internal Combustion Engine Factory.
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