JB/T 51128-1999 Single-cylinder diesel engine body product quality classification
Basic Information
Standard ID:
JB/T 51128-1999
Standard Name: Single-cylinder diesel engine body product quality classification
Chinese Name:
单缸柴油机 机体 产品质量分等
Standard category:Machinery Industry Standard (JB)
state:in force
Date of Release1999-12-30
Date of Implementation:2000-06-01
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T51128—1999
Single Cylinder Diesel Engine Body
Product Quality Classification
(Internal Use)
Published on 1999-12-30
National Machinery Industry Bureau
Implemented on 2000-06-01
JB/T511281999
This standard is a revision of JB/T51128.1~51128.394 "Product Quality Classification of Single Cylinder Diesel Engine Body". Only editorial changes were made to the original standard during the revision, and the main technical content remained unchanged. This standard replaces JB/T51128.1~51128.3-94 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Internal Combustion Engines. The drafting units of this standard are: Wujin Diesel Engine Body Factory and Shanghai Internal Combustion Engine Research Institute. The main drafters of this standard are: Shi Jianfang, Zhu Yadao, Li Shaoqiu. This standard was first issued in 1990 as JB/NQ215.1~215.3-90, and the standard number was adjusted to JB/T51128.151128.394 in September 1994.
1 Scope
Machinery Industry Standard of the People's Republic of China
Single-cylinder diesel engine block
Product quality classification
(Internal use)
JB/T51128—1999
Replaces JBT51128.1~51128.3—94
This standard specifies the product quality indicators, inspection methods and inspection rules for the cast iron engine block (hereinafter referred to as the engine block) of a reciprocating single-cylinder diesel engine with a cylinder diameter less than or equal to 200mm. This standard applies to the inspection and assessment of the product quality of single-cylinder diesel engine blocks. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T228—1987
GB/T231—1984
GB/T 1184—1996
GB/T1957—1980
GB/T1958—1980
GB/T2828—1987
GB/T31T—1997
GB/T3934—1983
GB/T9439—1988
JB/T7945—1999
JB/T9742—1999
JB/T9753—1999
3 Quality Indicators
Metal Tensile Test Method
Metal Brinell Hardness Test Method||t t||Tolerance of shape and position without tolerance value
Smooth limit gauge
Shape and position tolerance inspection regulations
Counting sampling procedure and sampling table for batch inspection (applicable to inspection of continuous batches) Inspection of smooth workpiece dimensions
General thread gauge
Gray cast iron parts
Gray cast iron
Mechanical properties test method
Internal combustion engine
Technical conditions for gray cast iron cylinder head and engine block castings Internal combustion engine to
Technical conditions for cast iron engine block
Engine block products shall be manufactured according to product drawings and technical documents approved by the prescribed procedures, and their technical requirements shall comply with the provisions of this standard. Engine block products are divided into two grades: qualified products and first-class products according to their different quality indicators. The material of engine block products shall not be lower than the HT200 grade specified in GB/T9439-1988. The hardness difference shall be specified in Table 1. 3.3
Hardness difference
Approved as qualified product by the State Machinery Industry Bureau on December 30, 1999
Implemented on June 1, 2000
JB/T51128-1999
3.4Dimensional tolerances, form and positional tolerances and surface roughness of main parts of the engine body 1Dimensional tolerances of main bearing holes, cylinder liner holes and camshaft bearing holes are graded as specified in Table 2 3.4.1
Main bearing hole
Camshaft bearing hole
Cylinder liner hole
Qualified product
The shape and positional tolerances shall comply with the provisions of GB/T1184, and their grades are shown in Table 3. Table 3
Cylindricity of main bearing hole
Cylindricity of camshaft bearing hole
Perpendicularity of cylinder liner hole axis to main bearing hole axisParallelism of camshaft bearing hole axis and main bearing hole axisCoaxiality of main bearing hole
Coaxiality of camshaft bearing hole
Jumping of cylinder liner shoulder support surface to cylinder liner hole axisFlatness of joint surface between machine body and cylinder head
3 The grading of surface roughness R value shall be as specified in Table 4. 3.4.3
Cylinder liner bore surface
Main bearing bore surface
Camshaft bearing bore surface
5 Casting defects and appearance quality
3.5.1 Casting defects not allowed in the engine body Table 4
Qualified products
Qualified products
a) The engine body is not allowed to have cracks, insufficient pouring, serious sand adhesion and other casting defects that reduce the structural strength of the engine body or affect cutting and positioning and clamping of castings;
b) The matching surface of the engine body and cylinder head, the main bearing hole and the threaded hole are not allowed to have any casting defects. 3.5.2 Casting defects allowed in the engine body
a) The height of the existing burrs and pouring riser residual roots is allowed to be no more than 2mm on the unprocessed surface; b) The classification of the allowable hole defects is as specified in Table 5. 2
Number of individual holes on each surface
and their size
JB/T51128-1999
Unprocessed surface
Processed surface
Note: Other provisions for holes shall comply with JB/T97423.5.3 The product surface shall be clean and free of rust. Qualified products
3.5.4 The unprocessed surface of the body shall be painted, and the paint surface shall be smooth without bubbles, peeling, etc. 3.6
The body shall be cleaned, and the oil channel shall not be allowed to leak after the oil pressure test. The body shall be tested by water pressure without leakage.
The service life of the body shall be classified according to the provisions of Table 6.
Inspection method
Qualified products
Tensile strength test shall be in accordance with the provisions of GB/T228, GB/T7945 and JB/T9742. Hardness test is in accordance with GB/T231.
Dimension tolerance is in accordance with GB/T3177 and GB/T1957. Thread tolerance is in accordance with GB/T3934.
Shape and position tolerance are measured by flat plate, height gauge, micrometer or measuring stand with indicator, etc., in accordance with GB/T1958. Surface roughness is tested by surface roughness specimen or surface roughness measuring instrument. Water pressure and oil pressure test are carried out by water pressure and oil pressure test device. Water pressure test method is in accordance with JB/T9742. Service life is mainly based on the use report of the main engine factory. Appearance quality is evaluated by visual inspection.
Inspection rules
Unqualified classification
According to GB/T2828, the quality characteristics of the inspected products that do not meet the requirements of the standards and product drawings are called unqualified. According to their importance to product quality, the unqualified quality of single-cylinder diesel engine body products are divided into Class A unqualified, Class B unqualified and Class C unqualified. The classification of unqualified product quality of single-cylinder diesel engine body is shown in Table 7. Qualified quality level AQL value
Single-cylinder diesel engine body products are divided into two levels of AQL values, qualified products and first-class products, as shown in Table 8. 5.3 Sampling plan
JB/T51128-1999
Use the normal inspection one-time sampling plan. The single-cylinder diesel engine body is subject to the normal inspection one-time sampling plan as shown in Table 8. In the table, Ac (qualified judgment number) and Re (unqualified judgment number) are calculated by the point method. Table 7
Classification of non-conforming
Tensile strength
Hardness and hardness difference
Hydraulic (oil pressure) test
Quality characteristics
Cracks, surface matching between engine block, cylinder liner and main bearing and inner surface casting defects of cylinder head screw hole Cylinder liner hole size tolerance D hole
Cylinder liner hole size tolerance D, hole
Main bearing hole size tolerance D hole
Main bearing hole size tolerance D. HolewwW.bzxz.Net
Camshaft bearing hole size tolerance D, Hole
Camshaft bearing hole size tolerance D Hole
Main bearing hole cylindricity D Hole
Main bearing hole cylindricity D. Hole
Camshaft bearing hole cylindricity D Hole
Camshaft bearing hole cylindricity D. Hole
Perpendicularity of cylinder liner hole axis to main bearing hole axis Parallelism of camshaft bearing hole axis to main bearing hole axis Cylinder liner surface roughness D.Hole
Cylinder liner surface roughness D, hole
Main bearing hole surface roughness D hole
Main bearing hole surface roughness D hole
Camshaft bearing hole surface roughness D hole
Camshaft bearing hole surface roughness D hole
Cylinder liner shoulder support surface cylinder liner hole axis runout body and cylinder head joint surface flatness
Main bearing hole coaxiality D hole
Main bearing hole coaxiality D hole
Coaxiality of wheel shaft bearing hole D hole
Coaxiality of camshaft bearing hole D hole
Casting quality: seams, sand sticking, and insufficient pouring on the unprocessed surface Number and size of individual holes: Number and size of individual holes on the unprocessed surface:
Paint layer quality, surface quality
Qualified products
First-class products
Unqualified classification
Inspection level
Sample size code
Sample number n
JB/T51128-1999
Table 8 Normal inspection of single cylinder cylinder head products A
Ac, Re
5.4 Inspection batch N
N-26-50
The inspection batch N is specified to be 26-50, and the inspection batch shall not be less than the lower limit of the specified batch range. If it is greater than the upper limit of the specified batch range, the products shall be divided into several batches of 26-50, and one of the batches shall be randomly selected for sampling inspection. 5.5 Inspection level
For Class A unqualified products, special inspection level S-1 shall be adopted, and for Class B and C unqualified products, general inspection level I shall be adopted. 5.6 Sample extraction
Samples should be extracted from user units and commercial departments. In this case, they are not subject to the lower limit of the batch range. If there is no stock at the above locations, with the consent of the relevant departments, samples can be extracted from the production line or from products that have been put into storage recently (within half a year). In this case, the batch range specified in 5.4 must be strictly followed.
5.7 Product quality grade assessment
5.7.1 Sample inspection
Samples should be inspected and assessed according to the various types of non-conformities specified in Table 7 and the sampling plan specified in Table 8, and in accordance with the provisions of Chapters 3 and 4.
5.7.2 Batch assessment
After all samples are inspected, if the number of non-conformities in a certain category is less than or equal to the Ac value, the category is judged as qualified. When the number of non-conformities in a certain category is greater than or equal to the Re value, the category is judged as unqualified. When the number of non-conformities in all categories is qualified, the batch of products is judged as qualified. 5.7.3 Quality Grade Assessment
5.7.3.1 After all samples have been inspected, if the number of unqualified items in each category in the sample is less than or equal to the Ac value of the first-class product, the inspected product shall be assessed as a first-class product; if the number of unqualified items in each category in the sample is less than or equal to the Ac value of the qualified product, the inspected product shall be assessed as a qualified product; if the number of unqualified items in one category in the sample is greater than or equal to the Re value of the qualified product, the inspected product shall be assessed as an unqualified product. 5.7.3.2 If a product is assessed as an unqualified product, it is allowed to be re-inspected once after half a year. If the re-inspection is qualified, it can still be assessed as a qualified product, but it shall not be assessed as a first-class product.
Mechanical Industry Standard
Single Cylinder Diesel Engine Body
Product Quality Grading
(For Internal Use)
JB/T51128—1999
Published and Distributed by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2, Shouti South Road, Beijing, Postal Code 100044)*
Book Size 880×12 30
2Word count 12000
1/16 Printing sheet 1/2
First edition in April 2000
Print run 1-500
First printing in April 2000
Price 1000 yuan
99-1271
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