This standard specifies the technical requirements, inspection rules and marking, packaging, transportation and storage of cast iron valve guides for internal combustion engines. This standard applies to cast iron valve guides for reciprocating piston internal combustion engines with a cylinder diameter of less than or equal to 200 mm. JB/T 5080-1991 Technical conditions for cast iron valve guides for internal combustion engines JB/T5080-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB5080--91
Technical Conditions for Cast Iron Valve Guides for Internal Combustion Engines
Published on July 1, 1991
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implemented on July 1, 1992
Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Cast Iron Valve Guides for Internal Combustion Engines
1 Subject Content and Scope of Application
JB5080-91
This standard specifies the technical requirements, inspection rules and marking, packaging, transportation and storage of cast iron valve guides for internal combustion engines. This standard applies to cast iron valve guides for reciprocating piston internal combustion engines with a cylinder diameter of less than or equal to 200mm (hereinafter referred to as valve guides).
2 Reference standards
GB9439
GB1800
GB 1184www.bzxz.net
GB2828
GB7216
GB1958
3 Technical requirements
Grey cast iron parts
Tolerances and fits General standard tolerances and basic deviations Shape and position tolerances Provisions for unmarked tolerances Batch-by-batch inspection Counting shaft sample procedure and sampling table (applicable to inspection of continuous batches) Grey cast iron mechanical properties test methods
Jinrun Brinell hardness test method
Grey cast iron metallography
Provisions for shape and position tolerance inspection
3.1 Valve guides shall be manufactured in accordance with product drawings and technical documents approved through the prescribed procedures and shall comply with the provisions of this standard. 3.2 The valve guide shall be made of grey cast iron, alloy iron or other cast iron that can meet the use requirements, and its mechanical properties shall be greater than or equal to the tensile strength value of HT200 specified in GB9439. 3.3 Valve guide hardness: grey cast iron is 170~241HB; alloy cast iron is 187~255HB. 3.4 The metallographic microstructure of the valve guide shall be that type A graphite is evenly distributed on fine lamellar pearlite (a small amount of type B and type D graphite is allowed), and the ferrite content shall not exceed 7% of the lamellar area. Evenly distributed discontinuous network phosphorus eutectic crystals are allowed, but continuous network phosphorus eutectic and free cementite are not allowed. 3.5 The inner and outer warm surfaces of the valve guide are not allowed to have dents, cracks, looseness, slag inclusions and foreign inclusions. The inner hole surface is not allowed to have pores, and the outer circle surface is allowed to have pores with a true diameter less than or equal to 1.5mm and a depth less than or equal to 0.5mm. The number of pores shall not exceed 3, and the distance between adjacent pores shall be greater than 5mm.
3.6 The dimensional tolerance grade of the valve guide shall be in accordance with the following tolerance grades specified in Table 2 of GB1800. 3.6.1 The tolerance grade of the outer cylindrical surface diameter is IT6, 3.6.2 The tolerance grade of the inner cylindrical surface diameter is IT8, 3.7 The shape and position tolerance of the valve guide shall be in accordance with the following tolerance grades specified in GB1184. 3.7.1 The cylindricality of the outer circle is grade 8,
3.7.2 The coaxiality of the outer circle axis to the inner axis is grade 9, 3.8 The roughness R. value of the inner and outer circle surfaces of the valve guide is 0.8μm. 3.9 The service life of the valve guide shall not be less than the overhaul period of the internal combustion engine. 3.10 During the warranty period of the internal combustion engine, if the valve guide is damaged due to poor manufacturing, the manufacturer shall be responsible for the three guarantees. Approved by the Ministry of Machinery and Electronics Industry on July 1, 1991 and implemented on July 1, 1992
4 Inspection rules
JB5080-91
4.1 The valve guide shall be inspected and qualified by the technical inspection department of the manufacturer and the product certificate shall be issued before it can be shipped. 4.2 When the ordering unit samples the product quality, it shall follow the provisions of GB2828. The sampling plan and qualified quality level shall be agreed upon by the supply and demand parties. 4.3 The mechanical properties of the valve guide shall be inspected in accordance with the provisions of GB977. 4.4 The hardness of the valve guide shall be measured with a Brinell hardness tester in accordance with the provisions of GB231. 4.5 The metallographic microstructure of the valve guide shall be inspected with a metallographic microscope in accordance with the provisions of GB7216. 4.6 The cylindricity of the outer circle of the valve guide shall be measured in accordance with the cylindricity error detection method in Appendix (4) of GB1958. 4.7 The coaxiality of the outer circle axis of the valve guide to the inner circle axis shall be measured in accordance with the coaxiality error detection method in Appendix 1 (10) of GB1958. 4.8 The surface roughness R value of the valve guide shall be measured with a surface roughness meter, or by using a surface roughness comparison sample block for comparison. 4.9 The durability test of the valve guide is allowed to be carried out together with the internal combustion engine bench durability test and the use test with supervision regulations. 5 Marking, packaging, transportation and storage
5.1 The manufacturer's name (or trademark) shall be marked on each valve guide. The marking position, size and method shall be in accordance with the product drawing. Care shall be taken not to damage the parts.
5.2 Each valve guide should be cleaned and treated for rust prevention before packaging, and then wrapped with strong and impermeable neutral paper or plastic film, and then packed into a packaging box. Each box should contain valve guides of the same model. The packaging box should indicate a.
Manufacturer name, logo (or trademark) and address; product model, name and part number:
Quantity:
Factory date,
5.3 The packaging box should be accompanied by a product quality certificate signed by the inspector. The certificate should indicate: a.
Manufacturer name, logo (or trademark) and address: product model, name and part number:
The product has passed the inspection and is allowed to leave the factory;
Inspection date.
5.4The packaged valve guide must be placed in a dry packaging box lined with waterproof paper, and ensure that it will not be damaged during the transportation. The total weight of each box should not exceed 50kg.
5.5 The packaging box should be marked with,
Manufacturer name, logo (or trademark) and address: Product model and name:
Total weight and quantity 1
Volume: Length × width × height:
Consignee and address:
"Handle with care", "Keep away from moisture" and other signs Packing date.
5.6 Valve guides should be stored in a ventilated and dry warehouse. Under the condition of proper storage, the manufacturer should ensure that the valve guides will not rust within 12 months from the date of leaving the factory.
Additional instructions:
This standard was proposed and coordinated by the Shanghai Internal Combustion Engine Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by the Shanghai Internal Combustion Engine Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard is Chen Hongzhi.
From the date of implementation of this standard, NJ28-64 "Technical Conditions for Valve Guides" will be invalid. 2
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