This standard specifies the structural type, technical requirements, inspection rules and marking, packaging, transportation and storage of integral single-layer rocker arm bushings. JB/T 7292.3-1994 Technical conditions for rocker arm bushings for internal combustion engines JB/T7292.3-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7292.3-94
Internal Combustion Engine Bushing
Technical Conditions for Rocker Arm Bushing
Published on 1994-07-18
Ministry of Machinery Industry of the People's Republic of China
Implementation on 1995-07-01
Mechanical Industry Standard of the People's Republic of China
Internal Combustion Engine Bushing
Technical Conditions for Rocker Arm Bushing
1 Subject Content and Scope of Application
JB/T 7292.394
This standard specifies the structural type, technical requirements, inspection rules and specifications, packaging, transportation and storage of integral single-layer rocker arm bushings. This standard applies to integral single-layer rocker arm bushings (hereinafter referred to as rocker arm bushings) for tractors, automobiles, engineering machinery, marine and fixed reciprocating piston internal combustion engines with a cylinder diameter of less than 200mm. The rocker arm bushings of internal combustion engines made of bimetallic materials can be implemented with reference to JB/T7292.2. 2 Reference standards
GB 1184
GB1800
GB2828
GB10448
GB10452
3 Structural types
Shape and position tolerances Specifications of tolerances without tolerances General standard tolerances and basic deviations Batch inspection Count sampling procedures and sampling tables (applicable to continuous batch inspection) Sliding bearings Cast copper alloys for single-layer and multi-layer bearings Sliding bearings Single-layer bearings Hardness test methods for barrier-reducing alloys The typical structural types of rocker arm bushings are shown in Figure 1. Figure 1
4 Technical requirements
4.1 Rocker arm bushings shall be manufactured according to product drawings and technical documents approved by the prescribed procedures and shall comply with the provisions of this standard. 4.2 Materials
4.2.1 Rocker arm bushings shall preferably be made of cast copper-based alloys specified in GB10448. The material number, chemical composition, metallographic structure and mechanical properties of the above materials are shown in Appendix A (Supplement). 4.2.2 Rocker arm bushings may also be made of other materials that meet the quality requirements. 4.3 Dimensions and tolerances
Approved by the Ministry of Machinery Industry on July 18, 1994
Implemented on July 1, 1995
4.3.1 Outer diameter D
JB/T 7292.394
The tolerance grade of the outer diameter D of the rocker arm bushing shall not be lower than IT74.3.2 Inner diameter d
4.3.2.1 The tolerance grade of the inner diameter d of the rocker arm bushing shall not be lower than IT74.3.2.2 The tolerance grade of the inner diameter d of the rocker arm bushing with boring or reaming amount may be IT8 as specified in GB1800, or may be agreed upon by both the supplier and the buyer.
4.3.3 The tolerance of the width B of the rocker arm bushing shall be as specified in Table 1. Table 1
Width B
>25~ 50
>50~80
> 80~120
4.3.4 Inner and outer chamfer dimensions
The inner and outer chamfer length c1c of the rocker arm bushing should preferably be 0.3, 0.5, 0.8, 1.02.0mm. 4.3.5 Inner and outer chamfer angles
4.3.5.1 The chamfer angle α of the rocker arm sleeve outer circle is generally 45°, and 15° can also be used. 4.3.5.2 The inner chamfer angle α of the rocker arm bushing is 45*. 4.4 Position tolerance
4.4.1 The coaxiality tolerance grade of the inner and outer ring axes of the broadcast arm envelope shall not be lower than grade 8 specified in GB1184. mm
4.4.2 The coaxiality tolerance grade of the inner and outer axis of the rocker bushing measured by mirror or by hand can be 9 grades as specified in GB1184, or can be agreed by both parties.
4.5 Surface roughness
4.5.1 Outer surface roughness
The outer surface roughness R. of the rocker bushing is 1.25μm. 4.5.2 Inner surface roughness
The inner surface roughness R. of the rocker bushing shall comply with the provisions of Table 2. Table 2
No machining allowance is left for the inner surface
Surface roughness
Surface roughness R,
Machining allowance is left for the inner surface
4.6 The inner and outer surfaces of the rocker bushing are not allowed to have burrs, scratches, magnetic damage and pressure damage. 4.7 The outer surface of the rocker arm bushing is not allowed to have casting defects such as cracks, pinholes and slag inclusions, but 3 smooth pores with a diameter not greater than 1mm and a depth not greater than 0.5mm are allowed.
4.8 The inner surface of the rocker arm bushing is not allowed to have casting defects such as cracks, pinholes and slag inclusions, but 2 smooth pores with a diameter not greater than 1mm and a depth not greater than 0.5mm are allowed.
4.9 If the user complies with the installation, maintenance and use rules specified in the instruction manual of the internal combustion engine, the warranty period of the rocker arm bushing shall not be less than the warranty period of the internal combustion engine.
5 Inspection rules
5.1 Inspection categories
Regular inspection;
Warehouse inspection:
Delivery acceptance.
: Inspection items
Dimensions:
Geometric accuracy:
Surface roughness;
Physical and chemical properties;
Appearance quality;
Marking, packaging.
5.3 Sampling methodwwW.bzxz.Net
JB/T7292.394
The sampling inspection and evaluation of rocker bushing products shall be carried out by both the supplier and the buyer in accordance with the sampling inspection rules specified in GB2828. 5.4 Inspection method
The hardness inspection method of rocker arm bushing shall be in accordance with the provisions of GB10452, see Table 3Table 3
Steel-based and aluminum-based alloy bars and tubes
Inspection conditions
HB2.5/62.5/10 is preferred. If the inspection area is too small, HB1/10/10 can also be used
For casting alloys with more sand limits, HB5/250/10 is used for inspection temperature
Note: HB5/250/10 means that the Brinell hardness should be obtained by using a ball head with a diameter of 5mm under a test load of 2.45kN and a loading time of 10s. Marking, packaging, transportation and storage
The outer surface of the packaging box should be marked with:
Manufacturer name, factory logo and address:
Product name, model or size code:
Quantity:
Packing date (year, month).
The outer surface of the packing box should be marked with:
Manufacturer name and address;
Product name and model;
Total weight and quantity:
Receiving unit and address;
"Handle with care", "Moisture-proof", "Pressure-proof" and other words and signs; Packing date (year, month).
6.2 Packing
6.2.1 Each arm bushing should be clean before packing, and should be oil-sealed or treated with other anti-corrosion treatments before being packed into the packing box. 6.2.2 Each packing box should be accompanied by a product certificate signed by the inspector of the quality inspection department of the manufacturer. 3
6.3 Transportation
JB/T 7292.3-94
The packing box must be packed in a dry packing box. The total weight of each packing box should not exceed 25kg, and it should be guaranteed not to be damaged during normal transportation.
6.4 Storage
The rocker bushing after packaging should be stored in a ventilated and dry warehouse. Under normal storage conditions, the manufacturer should ensure that the rocker bushing will not rust within 12 months from the date of packaging. A1 Material grade, chemical composition
A1.1 Alloy grade
JB/T7292.3-94
Appendix A
Rocker bushing material
(supplement)
CuSn12Pb2.CuPb5Sn5Zn5, CuPb10Sn10.CuPb15Sn8 and other copper-based alloys, A1.2 Chemical composition
The chemical composition of the alloy shall be in accordance with the provisions of Table A1. Table A1
Alloy elements
Note: 1) Contains Ni.
CuSn12Pb2
Residue"
11.0~13.0
0. 05~0. 40*m
CuPb5Sn5Zn5
Residue"
4. 0~6. 0
2) For continuous casting, the phosphorus content can be increased to 1.5% by negotiation.
3) The chemical element content of this alloy is different from that of the alloy for thin-walled multilayer bearings. 4) The phosphorus content can be determined by negotiation.
Material hardness
A2.1 The hardness of CuSn12Pb2 alloy is greater than or equal to 80HBS. A2.2CuPb5Sn5Zn5 alloy has a hardness greater than or equal to 60HBS, A2.3CuPb10Sn10 alloy has a hardness greater than or equal to 65HBS. A2.4CuPb15Sn8 alloy hardness greater than or equal to 60HBSA3 material metallographic structure
The metallographic structure of the material shall comply with the provisions of the corresponding standards.
CuPb10Sn10\
Residue "
9.0~11. 0
CuPb15Sn8
Residue"
13.0~17.0
Additional instructions:
JB/T7292.3--94
This standard was proposed and managed by the Shanghai Internal Combustion Engine Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Shanghai Internal Combustion Engine Research Institute. The main drafters of this standard are Bao Xidi and Xu Liming.
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