Some standard content:
JB/T 8064. 1-
This standard currently includes the following two units under the general title, each unit is an independent part. Unit 1: JB/T8064.1-96
Technical conditions for compressed gas springs
Unit 2: JB/T8064.2-96
Technical conditions for lockable gas springs
This standard is proposed and managed by the Mechanical Standardization Research Institute of the Ministry of Machinery Industry. The responsible drafting units of this standard: Spring Product Quality Supervision and Inspection Center of the Ministry of Machinery Industry, Institute of Automation of the Chinese Academy of Sciences. The main drafting units of this standard: Longyan Aircraft Manufacturing Plant, Wuxian Xiangcheng Special Pneumatic Spring Factory, Shaoyang Auto Parts Factory, Kunshan Hydraulic Pneumatic Motor General (in order of the first stroke of the word). 60
Standard of the Machinery Industry of the People's Republic of China
Technical Conditions for Compressed Gas Springs
JB/T 8064. 1--- 96
This standard specifies the terms, marking, technical requirements, test methods, inspection rules, marking and packaging, transportation, storage, etc. of compressed gas springs (hereinafter referred to as gas springs).
This standard applies to gas springs filled with nitrogen or inert gas as working medium. 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 will be revised, and the parties using this standard should explore the possibility of using the latest version of the following standards. GB/T1771-91 Determination of neutral salt spray resistance of paints and varnishes GB1800-79 General tolerances and fits Standard tolerances and basic deviations GB/T2348--93 Hydraulic and pneumatic systems and components Cylinder inner diameter and piston rod outer diameter GB2349-80 Hydraulic and pneumatic systems and components Cylinder piston stroke series GB 2828-87
Batch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection) Neutral salt spray test (NSS test)
GB 6458---86
Metallic coatings
Rating of electroplated samples after corrosion test of metallic coatings on substrates with cathode GB 6461--86
GB/T13913--92 Technical requirements and test methods for autocatalytic nickel-phosphorus coatings JB 2864--81
Electroplating and chemical treatment for automobiles
JB/Z111--86Automobile paint coating
3 Types
3.1 The schematic diagram of the appearance of the gas spring and the force-displacement curve are shown in Figure 1. The expansion process
Hydraulic damping section M
Pneumatic damping section
Extension length!
The Ministry of Machinery Industry of the People's Republic of China approved 602 on October 3, 1996
1997~07-01 implementation
3.2 The recommended type of gas spring joint is shown in Figure 2. U--Double ears
4 Terms, symbols and definitions of gas springs
The terms, symbols and definitions of gas springs are shown in Table 1. Technique
Cylinder outer diameter
Rod diameter
Stretch length
-cycle
Stretch speed
Starting force
Pneumatic damping section
Hydraulic damping section
Minimum stretching force
Maximum stretching force
Minimum compression force
JB/T8064.1-96
)--single piece
1. Single ear
B ball head
Outer diameter of gas spring cylinder
Diameter of gas spring piston rod
The distance between the centers of the two connecting parts when the gas spring piston rod is freely extended to the limit positionThe axial displacement of the piston rod when it is compressed from the extended state to the minimum installation sizeThe piston rod is compressed and extended once according to the specified strokeThe average speed of the piston rod freely extending from the end of the specified stroke to the initial positionThe external force required for the gas spring to move the piston rod after it has been kept in the extended state for a certain period of timeThe area of the piston movement affected by gas damping from D to M during the extension of the piston rodThe area of the piston movement affected by liquid damping from M to A during the extension of the piston rodIn the extension process, the extension force measured at Cmm from the starting point of the working stroke is the minimum extension forceIn the extension process, the extension force measured at Cmm from the end point of the working stroke is the maximum extension forceIn the compression process, the extension force measured at Cmm from the starting point of the working stroke is the maximum extension force The compression force measured at mm is the minimum compression force 608
Maximum compression force
Nominal force
Dynamic friction force
Elastic force ratio
No.
Note: S≤80mm.C5mm
S>80mm,C=10mm
5 Marking
5.1 Marking method
JB/T 8064.1--96
Table 1 (end)
Definition or explanation
During the compression process, the compression force measured at Cmm from the end of the working stroke is the maximum compression force F,=-(F,-+-F,)/2
The gas spring force performance characteristics do not meet the requirements
F,=(F3-- F)/2
Let; Fh=(F,+F2)/2,as-Fh/F
The marking of gas spring consists of code, piston rod diameter, cylinder outer diameter, stroke, extension length, joint type, nominal force. The regulations are as follows: YQ
XX/XX-XXX-
Nominal force
Joint type
-Extension length
Cylinder outer diameter
Piston rod diameter
Gas spring code
5.2 Marking example
Piston rod end connection type
Cylinder end connection type
Example: The piston rod diameter of the gas spring is 10mm, the cylinder outer diameter is 22mm, the stroke is 260mm, the extension length is 650mm, the joint type is 0-0, and the nominal force is 550N.
Marked as: YQ10/22--260--650(0-0)5506 Technical requirements
6.1 The product shall comply with the requirements of this standard and be manufactured according to the product drawings and technical documents approved by the prescribed procedures. 6.2 Dimensions and appearance quality
6.2.1 The piston rod diameter and piston stroke of the gas spring shall be selected in accordance with GB/T2348 and GB2349. When the piston rod diameter and piston stroke of the gas spring meet the above standards, it can be indicated in the technical documents: The outer diameter and stroke of the piston rod of this product meet the provisions of the national standards GB/T2348 and GB2349.
6.2.2 The dimensional tolerance of the extended length of the gas spring shall be manufactured according to the IT16 level precision specified in GB1800. 6.2.3 The electroplating layer shall comply with the provisions of GB/T13913 and JB2864. The main surface shall be smooth and free of defects such as alkali contact, scratches, peeling, blistering, pinholes, tumors, spots, and color difference.
6.2.4 The chemical treatment layer shall comply with the provisions of JB2864, with uniform color and no red rust, obvious spots and attached sediments. 6.2.5 The paint coating shall comply with the provisions of JB/Z111. The paint layer shall be flat, the color shall be consistent, there shall be no obvious pitting, no serious sagging, and the bottom shall not be exposed. 6.3 Performance requirements
6.3.1 There shall be no jamming phenomenon when the gas spring is cycled, that is, the dynamic friction force shall not be greater than the maximum value within one cycle. The nominal force limit deviation and the maximum value of dynamic friction force shall comply with the provisions of Table 2. 60.4
201400
401～800
8011600
JB/T8064.1-96
Nominal force limit deviation
Note: The force limit deviation can also be used asymmetrically according to the agreement between the supplier and the buyer, and its tolerance value remains unchanged. 6.3.2 The starting force of the gas spring should be less than 1.5F3 The maximum value of dynamic friction
6.3.3 The extension speed of the gas spring should be between 100 and 200mm/s. If there are special needs, it can be determined by the agreement between the supplier and the buyer. 6.3.4 The elastic force ratio of the gas spring and the length of the hydraulic damping section are interrelated and should be determined by the agreement between the supplier and the buyer according to the load conditions. 6.3.5 Corrosion resistance
The gas spring should be able to withstand a 96h neutral salt spray test. After the test, there should be no visible corrosion defects on the surface of the piston rod and the cylinder. 6.3.6 Thermal shock resistance
Gas springs should be able to withstand low temperature -30℃ high temperature 80℃ thermal cycle test: Gas springs in harsh operating environments should be subjected to 12 repeated thermal shock tests. After the test, the nominal force attenuation of the gas spring should not be greater than 8%.
Gas springs in normal operating environments should be subjected to 2 repeated thermal shock tests. After the test, the nominal force attenuation of the gas spring should not be greater than 5%. 6.3.7 Cycle life
Gas springs that have undergone thermal shock resistance tests should also be able to withstand 20,000 cycle life tests. After the test, the total attenuation of the nominal force should be less than 13%, and the dynamic friction force should comply with the provisions of Table 2. 6.3.8 Tensile strengthWww.bzxZ.net
The gas spring is stretched at 4 times the nominal force for 5 minutes, and the gas spring force performance should remain unchanged. The gas spring is stretched at 8 times the nominal force for 5 minutes, and the gas spring is allowed to fail but must not be dismembered. 7 Test method
7.1 Dimension and appearance inspection
7.1.1 Use a special or general measuring tool with a graduation value less than or equal to 0.02mm to inspect the dimensions. 7.1.2 The appearance quality shall be inspected by visual inspection or a 4x magnifying glass. The electroplating layer, chemical treatment layer and paint layer shall be inspected in accordance with the relevant provisions of GB/T13913, JB/Z111 and JB2864 respectively, and the test results shall comply with the provisions of 6.2.3 to 6.2.5. 7.2 Force performance test
7.2.1 Test conditions
The test is carried out at 20℃±2℃. Before the test, the gas spring should be in an environment of 20℃±2℃ and always kept in an extended state. The piston rod should not be pressed. It should be placed for more than 2h. The measuring speed of the test machine is: 200mm/min. The force measurement accuracy of the test machine is not less than 1%, and the displacement measurement accuracy is not less than 1%.
7.2.2 Test method
Mount the gas spring piston rod downward vertically on the test machine using the connectors at both ends. Record the bottom power in the first cycle of the start-up, and record the extension force and compression force F1, F2, Fs, F4 in the second cycle, and calculate the nominal force, dynamic friction force and elastic force ratio of the gas spring. When measuring the hydraulic damping length, the measuring speed should be increased to 5~~8mm/s7.3 Extension speed test
7.3.1 Test conditions
The test is carried out in an environment of 20℃±2℃. Before the test, the gas spring should be placed in an environment of 20℃±2℃ for more than 2h. The scale value of the timer is less than or equal to 1/100s.
7.3.2 Test method
JB/T 8064. 1-96
During the test, the piston rod of the gas spring is clamped vertically downward on the testing machine, and the active rod is pressed into the specified stroke. Then, the external force is suddenly removed to make the active rod extend by itself. The extension time 1 and the extension distance S are measured, and the extension speed (average speed) can be calculated according to formula (1). The test results should comply with the provisions of 6.3.3.
Where:!
Extension speed;
S stroke;
·Extension time.
7.4 Corrosion resistance test
The corrosion resistance test of gas springs shall be carried out in accordance with the provisions of GB/T1771 and GB6458, and the test results shall comply with the provisions of 6.3.5. 7.5 Thermal shock resistance test
Put the gas spring in a 30℃+2C environment for 6 hours, and install it on the test machine within 10 seconds after taking it out, so that the piston rod is vertically downward, and the gas spring is operated for 5 cycles within 2 minutes. Then put the gas spring in an environment of 80℃±2C for 6 hours, and install it on the test machine within 10 seconds after taking it out, so that the piston rod is vertically downward, and the gas spring is operated for 5 cycles within 2 minutes. The above is a thermal shock. After the test, place the gas spring in a 20℃±2C environment for 4 hours, and its nominal force attenuation shall comply with the provisions of 6.3.6. 7.6 Life test
Install the gas spring that has been tested for thermal shock resistance on the testing machine, and operate the gas spring downward with the piston rod to cycle. The frequency of the cycle is 4 to 10 times/min. During the test, the temperature of the gas spring cylinder should be less than 50C. After every 5000 cycles, measure the force performance according to the test method of 7.2. After 20,000 cycles, the measured results should comply with the provisions of 6.3.7.
7.7 Tensile strength test
Fix the gas spring on the testing machine, load it at a speed of 2mm/min, and test it according to the provisions of 6.3.8. 8 Inspection rules
8.1 Inspection classification
Product inspection is divided into type inspection and factory inspection. 8.2 Type inspection
Type inspection should generally be carried out in the following situations: a) Trial type identification of new products or old products for transfer to factory production; b) After formal production, if there are major changes in structure, materials, and processes that may affect product performance; ) During formal production, regular inspections should be carried out after a certain amount of production has been accumulated; d) When the product is resumed after a long period of suspension; e) When the results of the final inspection are significantly different from those of the last type inspection; f) When the national quality supervision agency proposes a requirement for type inspection. 8.2.1 Defects
Gas springs that do not meet the technical requirements specified in product technical standards, process documents, and drawings constitute defects. According to the severity of the defects, they are divided into:
A Defect item (fatal defect)
B Defect item (serious defect)
(Defect item (general defect)
See Table 3 for specific contents.
A Defect item
Resistance to cold and hot shock performance
Cycle life
Tensile strength
8.2.2 Sampling method
8.2.2.1 Determination of inspection batch
JB/T 8064. 1-
B Defect item
Force characteristics
C Defect item
Dimension and appearance quality
Neutral salt spray resistance
a) The inspection batch must be qualified gas spring products, and 500 gas springs are one inspection batch. If the number of products is more than 500 pieces, the sampling personnel shall arbitrarily divide the inspection batches into several batches of 500 pieces each, and then randomly determine the inspection batches as the objects of spot inspection. b) If the number of products is not more than 50 pieces, sampling shall not be conducted for the inspection batches, and the inventory products shall be selected for sampling. 8.2.3 Sample selection
8.2.3.1 Non-destructive inspection items shall share one sample. If the number of products is more than 280 pieces, the inspection level specified in GB2828 shall be followed! , Sample size code F, normal inspection sampling plan, 20 gas springs are selected; if the number of products is less than 280, then according to the general inspection level specified in GB2828 [, Sample size code E, normal inspection sampling plan, 13 gas springs are selected 8.2.3.2 Hot and cold shock resistance, cycle life, tensile strength share a sample, in the inter-inspection batch, according to the special inspection level S-1, sample size code B, 3 gas springs are selected according to the normal sampling plan specified in GB2828. 8.2.4 Total number of samples
50≤N<280, the total number of samples is 16.
280≤N≥500, the total number of samples is 23 8.2.5 Acceptable quality level (AQL)
A defect item, B defect item The qualified quality level is 4.0 each. The qualified quality level of C defect items is 6.5. 8.3 Factory inspection
All products must be inspected before leaving the factory. 8.3.1 Inspection items
The inspection shall be carried out according to Table 4, and the ambient temperature shall be 20℃±2℃. Table 4
Inspection items
Nominal force
Stretch length
Force characteristic curve
Stretch speed
Inspection category
8.3.2 Acceptable quality level (AQL)
Inspection method and requirements
Perform according to 7.2 on the testing machine. Perform according to 7.1.2 if it meets the requirements of Table 2. Perform according to 7.1.1 if it meets the requirements of 6.2.3~6.2.5. Perform according to 7.2 if it meets the requirements of 6.2.1.6.2.2. Perform according to 7.3 if it meets the requirements of 6.3.1.6.3.2 and 6.3.4. Perform according to 7.3 if it meets the requirements of 6.3.3
8.3.2.1 If there are unqualified items in the mandatory inspection items, the part shall be directly judged as unqualified. 8.3.2.2 Acceptable quality level (AQL) of random inspection items shall be in accordance with the relevant provisions of type inspection. 9 Marking, packaging, transportation, storage
9.1 Product marking
Each gas spring product should be marked with the following in a conspicuous position: a) Product name, model or mark;
b) Manufacturer's name;
c) Production date or production batch number;
d) High-pressure products must not be disassembled at will;
e) Trademark;
f) Certificate of conformity.
9.2 Packing box marking
The following markings should be on the gas spring packaging box: a) Product name, model;
b) Manufacturer's name and address;
c) Quantity of products in the box;
d) Overall dimensions and gross weight;
e) Factory date;
f) Marking "High temperature protection", "Handle with care", etc. 9.3 Packaging
JB/T8064.1—96
9.3.1 Each gas spring product shall be packed in a plastic bag, and each gas spring in the packing box shall be separated by a flexible material. The gross weight of each box shall not exceed 30kg.
9.3.3 The packing box shall be accompanied by a certificate of conformity stamped by the technical inspection department. 9.3.4 Transportation
Gas springs shall be protected from mechanical damage and rain during transportation. 9.3.5 Storage
Gas spring products should be stored in a dry, ventilated warehouse, with no acid, alkali or other corrosive gases around. Under normal storage conditions, there should be no rust on the coating, peeling of the paint, etc. within 3 years, and the nominal force attenuation should not be greater than 5%.
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