JB/T 51122-2000 Diesel engine low pressure oil hose assembly product quality classification JB/T51122-2000 standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T51122-2000
Diesel Engine Low-Pressure Oil Delivery Hose Assembly
Product Quality Classification
(Internal Use)
Published on 2000-08-31
National Machinery Industry Bureau
Implemented on 2000-12-01
JB/T511222000
This standard is a revision of JB/T51122.1~51122.3-94 "Product Quality Classification of Low-Pressure Rubber Oil Pipe Assembly for Diesel Engines". During the revision, only editorial changes were made to the original standard, and the main technical content remained unchanged. This standard replaces JB/T51122.1~51122.3-94 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 Shanghai Internal Combustion Engine Research Institute and Shanghai Second Vehicle Parts Factory. The main drafters of this standard are Qu Junming, Wang Wenxiang and Chen Linshan. This standard was first issued in October 1987, and the standard number was adjusted to JB/T5112.1~5112.3-941 in September 1994.
Mechanical Industry Standard of the People's Republic of China
Diesel Engine Low-pressure Fuel Delivery Hose Assembly
Product Quality Classification
(Internal Use)
JB/T51122—2000
Replaces JB/T51122.1-511223—94
This standard specifies the quality indicators, test methods and inspection rules of diesel engine low-pressure fuel delivery hose assembly (hereinafter referred to as hose assembly) products.
This standard applies to the quality inspection and assessment of diesel engine low-pressure oil delivery hose assembly products 2 Reference 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 will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 6991999
GB/T2828—1987
JB/T6015—2000
3 Quality indicators
High-quality carbon structural steel
Batch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection) Technical conditions for diesel engine low-pressure oil delivery hose assemblies Hose assemblies should be manufactured according to product drawings and technical documents approved by the prescribed procedures and comply with relevant standards. The materials and surface treatment of parts shall be as specified in Table 1. If other materials are used instead, their mechanical properties shall not be reduced. Table 1
Parts name
Articulated liner joint
Ball liner joint
Inner cone liner joint
Face liner joint
Shell nut
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20 (GBT699)
30 (GBT699)
08F (GBT 699)
According to JBT6015
Surface treatment
Oxidation or galvanizing
Products are 3.2μm.
3.3The thread tolerance of the outer nut is 6H. Thread surface roughness R: qualified products are 6.3um, 3.4
Parallelism tolerance of both ends of the hinged liner joint: qualified products are 0.10mm, 3.5 The flatness tolerance of both ends of the hinged liner joint is 0.05mm. 3.6
The symmetry tolerance of both ends of the hinged liner joint is 0.08mm. 3.7 The flatness tolerance of the sealing surface of the end-face liner joint is 0.05mm. The National Machinery Industry Bureau approved the quality of the product as 0.08mm on 2000-08-31.
2000-12-01 implementation
JB/T51122—2000
3.8 The surface roughness R of the sealing surface of the hinged liner joint is 3.2um. 3.9 The surface roughness R of the sealing surface of the ball-type liner joint is 1.6um. 3.10 The surface roughness R of the sealing surface of the inner cone liner joint is 1.6μm. 3.11 The surface roughness R of the sealing surface of the end face liner joint is 1.6μm. 3.12 There shall be no cracks on the hose surface, and the parts shall not have cuts and dents, scratches and rust that affect the use. For parts coated with a covering layer (such as galvanizing, etc.), the coating surface shall be firmly bonded and smooth, and no defects such as blistering, peeling and plating leakage are allowed. 3.13 The connection between the hose and the joint shall be flat. The inner wall of the hose shall be smooth and unobstructed. The minimum inner diameter passing amount of the hose assembly shall be checked by the mandrel or steel ball specified in Table 2, and it shall be able to pass smoothly without scratching the inner rubber layer. Table 2
Inner diameter of hose
Minimum inner diameter passing amount
3.14 The amount of buckle during hose assembly shall ensure that the joint is assembled securely. The hose assembly shall be subjected to a pull-off test. The weight of the hammer during the test is W: 1W for qualified products and 2W for first-class products. The test duration shall not be less than 5 minutes. The hose assembly shall not fall off or loosen. W is calculated according to formula (1):
W=16pD| ... The test pressure of qualified products shall not be less than 2 times the working pressure, and that of first-class products shall not be less than 3 times the working pressure. The duration shall not be less than 30 seconds, and there shall be no leakage or rupture. 3.19 The burst test shall be carried out in accordance with the requirements of 4.12 of JB/T6015-2000. 3.20 The installation dimensions of the hose assembly shall comply with the agreement between the supplier and the buyer. 4 Test method
Inspection of hose assembly parts
The equipment, instruments and measuring tools used in the inspection must be approved by the prescribed procedures or recognized in the industry and within the validity period. The surface roughness of the parts shall be checked with a profilometer or a surface roughness comparison sample. 4.2 Minimum inner diameter passing test
Put a mandrel or steel ball of the specified size into the hole of the hose assembly, and observe whether the mandrel or steel ball can pass smoothly, and whether there is any scratch on the inner surface of the hose.
4.3 Pull-off test
Perform a hammer test according to the quality specified in 3.14, and the duration should be no less than 5 minutes. Observe whether there is any pull-off or looseness at the hose joint. 4.4 Pressure test
Perform on a pressure test bench. After the test pressure reaches the specified value, the duration should be no less than 30 seconds. Observe whether there is any leakage, rupture or local abnormal deformation at all parts of the hose. 4.5 Burst test
JB/T51122—2000
Perform on a burst test bench. After the test pressure reaches the specified value, observe whether there is any burst at all parts of the hose. 4.6 Measurement of the cleanliness of the inner surface of the hose assembly
The measurement parts, instruments, cleaning fluid, preparation work and operating steps shall comply with the provisions of 5.6 of JB/T6015-2000. 4.6.1
Calculation of impurities
W —— total mass of impurities, g;
W total = G2-G
mass of filter membrane before filtration, g;
- mass of filter membrane after filtration, g.
4.6.3 Cleanliness calculation shall be in accordance with the provisions of 5.6.7 of JB/T6015-2000. 4.7 Inspection of hose assembly material
The material of each part can be inspected in the factory physical and chemical laboratory or professional testing unit 5 Inspection rules
5.1 Classification of non-conformities
According to GB/T2828, the quality characteristics of the inspected products that do not meet the standards or product drawings are called non-conformities. According to their importance to product quality, non-conformities are generally divided into: Class A non-conformities, Class B non-conformities, and Class C non-conformities. Class A non-conformities: The extremely important quality characteristics of the product do not meet the requirements; Class B non-conformities: The important quality characteristics of the product do not meet the requirements; Class C non-conformities: The general quality characteristics of the product do not meet the requirements. The non-conformity classification of the quality characteristics of hose components is according to Table 3. Table 3
Unqualified classification
Pressure test
Pull-off test
Cleanliness of inner surface of tubing assembly
Explosion test
Material of rubber tube
Whether the joint is loose after buckling
Surface roughness of sealing surface
Minimum amount of inner diameter passing
Thread accuracy of outer nut
Quality characteristics
Parallelism of both end faces of articulated liner joint
Flatness of both end faces of articulated liner joint
Flatness of sealing surface of end-face liner joint Installation size of hose assembly||tt| |Classification of non-conforming
Qualified quality level AQL
JB/T51122—2000
Table 3 (end)
Quality characteristics
Roughness of internal thread of outer nut
Symmetry of both ends of articulated liner joint
Material of liner joint
Material of outer nut
Material of sleeve
Outer diameter of sleeve after crimping
Packaging of hose assembly
Appearance quality of hose assembly
AQL values ​​are specified for hose assembly according to the two grades of qualified product and first-class product (see Table 4). 5.3 Sampling plan
Use the normal inspection one-time sampling plan (see Table 4), and Ac and Re in the table are calculated by the point method. Table 4
Classification of nonconformities
Inspection level
Sample size code
Sample size store
Qualified products
First-class products
5.4 Inspection batch N
N-281~500
The specified batch N is 281~500 pieces. The inspection batch shall not be less than the lower limit of the specified batch. If it is greater than the upper limit of the specified batch, the product batch
shall be divided into several batches, and one of the batches shall be randomly selected for sampling inspection. When sampling by users or sales agencies, the batch size is not limited. 5.5 Inspection level
For Class A nonconformities, the special inspection level S-1 shall be used, and for Class B and C nonconformities, the general inspection level I shall be used. 5.6 Sample extraction
Usually, samples should be randomly extracted from user units, commercial departments or parts companies, and at this time, they may not be restricted by the lower limit of the batch range. If the samples are taken from the products that have been put into storage in the near future (within half a year), the batch range specified in 5.4 must be strictly followed. 5.7 Product Quality Grade Assessment
5.7.1 Sample Inspection
The samples shall be inspected and assessed according to the non-conforming classification specified in Table 3 and the sampling plan specified in Table 4, and in accordance with the provisions of Chapter 4 and Chapter 5.5.7.2 Batch Assessment
After all samples have been inspected, if the number of non-conforming items in a certain category is less than or equal to Ac, the category shall be judged as qualified: When the number of non-conforming items in a certain category is greater than or equal to Re, the category shall be judged as non-conforming. When the number of non-conforming items in all categories is qualified, the batch of products shall be judged as qualified.
5.7.3 Quality Grade Assessment
5.7.3.1 After all samples have been inspected, when the number of unqualified items of each category in the sample is less than or equal to Ac of first-class products, the inspected product shall be assessed as a first-class product; when the number of unqualified items of each category in the sample is less than or equal to Ac of qualified products, the inspected product shall be assessed as a qualified product. When the number of unqualified items of one category in the sample is greater than or equal to Re of qualified products, the inspected product shall be assessed as an unqualified product. 5.7.3.2 After 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
Diesel Engine Low-pressure Fuel Delivery Hose Assembly
Product Quality Grading
(Internal Use)
JB/T51122—2000
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)*
1/16 Sheet 1 /2
2Word count: 12000
Size: 880×1230
First edition: November 2000
Print run: 1-500
First printing: November 2000
Price: 1000 yuan
2000-152
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