The Sixth Machinery Industry Department of the People's Republic of China Cylindrical Shock absorber CB786-74 The cylindrical shock absorber (hereinafter referred to as shock absorber) specified in this standard is oil-resistant and is used for shock absorption and buffering of ship main engines, auxiliary engines and equipment. , Type, basic parameters and dimensions 1. Basic parameters of shock absorber are as shown in Table 1 YU-2300 Rated load (kG) Deformation under rated load (radial, mm) 0.3~0.7 Weight (kg) Note: The deformation values of shock absorbers under rated load should be matched in groups as much as possible during use, so that the deformation value of the selected shock absorber is close to the average deformation value of the group. 2. The dimensions of the shock absorber are shown in the figure below Issued by the Sixth Ministry of Machinery Industry Marking Example Cylindrical shock absorber with a rated load of 2300 kG: Shock absorber YU-2300CB786--74 Implemented on August 1, 1974 Wuxi Shock Absorber Factory Free Standard Network (ww.freebz.net) No registration is required to download Drafting Total 8 pages Page 2 CB786-74 II. Technical requirements 3. The shock absorber shall be manufactured in accordance with the requirements of this standard and the unified drawings. 4. The shock absorber shall be able to work normally under the following conditions: (1) The ambient temperature is -5° to +70°C; (2) The relative humidity does not exceed 98%. 5. Shock absorbers shall be made of nitrile rubber compound, and the physical and mechanical properties of the rubber shall comply with the requirements of Table 2. Sequence Tear strength Elongation Permanent deformation Shore hardness Brittle temperature Kiln's aging coefficient70°C×96 hours Expansion weight of a sample with a size of 10×10×10mm immersed in special diesel for 24 hours at room temperatureRatio to the expansion weight of a sample with a size of 10×10×10mm immersed in 10% salt solution for 24 hoursAdhesion strength between rubber and metal 6. The metal parts of the shock absorber shall be made of carbon steel. Refers to ≥100kG/cm2 ≥450% <25% -40°℃ (-0,2~+1)%bzxZ.net 30kG/cm2 7. The rubber surface of the shock absorber should be free of lumps, cracks, delamination with metal and under-pressure. Standard GB528-65 GB528-65 GB528—65 GB531-65 HG4—554—67 HGB4018—60 HGB4041-60 HGB4044-60 8. The rubber surface of the shock absorber is allowed to have: mold marks, slight bumps and grooves, rough lines and burrs, scratches and dents not exceeding 1.5mm deep, and bubbles. The local separation of rubber and metal shall not exceed 1 place within every 200mm of the periphery, and its depth shall not exceed 5mm and its length shall not exceed 30mm. Rubber overflow on the non-supporting surface of the metal is not considered a defect, and it is allowed to be removed and repaired. The rubber part of the shock absorber shall fully comply with the provisions of this standard after vulcanization. 9. The rubber surface of the shock absorber should be coated with anti-aging glue, and the metal surface should be coated with anti-corrosion shellac paint. 10. The positive deviation of the shock absorber weight should not be greater than 5%, and the negative deviation is unlimited. III. Acceptance rules and test methods 11. The shock absorber should be accepted by the technical inspection department of the manufacturer and a certificate of conformity should be issued. 12. The appearance quality of each shock absorber should be checked in accordance with the provisions of Articles 7, 8, 9 and 10 of this standard. 13. Each shock absorber shall be subjected to a deformation test under rated load on a universal testing machine or a special dynamometer, and its radial deformation shall comply with the provisions in Table 1. (The deformation data should be provided to the installation unit.) Test method: Start the universal testing machine or special dynamometer to make the rubber part of the shock absorber deform radially at a speed of 10-15mm per minute. When the load is gradually increased to the rated load specified in Table 1, the radial deformation is measured. Each shock absorber needs to be repeated three times, and the time interval between each time shall not be less than 1 minute. During the interval time, the shock absorber should be in a free state. 14. The shock absorber should be tested for rubber physical and mechanical properties. Its various indicators should comply with the provisions in Table 2, and the manufacturer should conduct a type test according to Table 2 every six months. Shock absorbers that have undergone type tests shall not be delivered. IV. Marking, packaging and storage 15. The shock absorber should be marked with the manufacturer's trademark, logo code and batch number, and the deformation data under rated load and the manufacturing date should be stamped on the metal parts of the shock absorber. 16. The shock absorber should be packed in a wooden box lined with moisture-proof paper. The box should contain the packing list, product certificate and deformation data under rated load. 17. In addition to general transportation matters, the packaging box should also be marked with "handle with care", "upward" and "moisture-proof". 18. The shock absorber should be stored in a well-ventilated warehouse with a room temperature of -5° to 30°C and the following requirements should be met: (1) Avoid direct sunlight, (2) Keep it 1m away from heat and light sources, (8) Avoid contamination by oil, paint and acid substances, and (4) Keep the shock absorber in a free state. 19. The storage period of shock absorbers is 1 year, and the service period is 5 years. If the storage period exceeds the period, the service period will be shortened accordingly. Printed in 1974 Free Standard Network (ww.freebz.net) can be downloaded without registration Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.