This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, storage, etc. of exhaust mufflers. JB/T 5081-1991 Technical requirements for exhaust mufflers for small and medium power diesel engines JB/T5081-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T5081-91
Exhaust Muffler for Small and Medium Power Diesel Engines
Technical Conditions
Published on July 1, 1991
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Implementation on July 1, 1992
Mechanical Industry Standard of the People's Republic of China
Exhaust Muffler for Small and Medium Power Diesel Engines
Technical Conditions
1 Subject Content and Scope of Application
JB/T5081-91
This standard specifies the technical requirements, test methods, inspection rules and markings, packaging, storage, etc. of air-holding mufflers (hereinafter referred to as mufflers).
This standard is applicable to small and medium power diesel engines and can also be used as a reference for other diesel engines. 2 Reference standards
GB2828
Count sampling procedures and sampling tables for batch inspection (applicable to continuous batch inspection)GB4759 Measurement methods for exhaust silencers for internal combustion enginesZBY107
Technical conditions for electric vibration tables
3 Technical requirements
3.1 The parts of the silencer shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 3.2 When the design changes of the silencer involve performance and installation dimensions, they shall be carried out after the supply and demand parties reach a consensus through consultation. 3.3 The insertion loss D and power loss ratio* of the silencer shall comply with the provisions of Table 1, Table 1
Type of silencer
Insertion loss D
Power loss ratio,
3.4 ​​The silencer shall be subjected to vibration test in accordance with the provisions of Article 1.3.2. After the test, the silencer shall not have cracking, looseness, gas and deformation. 3.5 After the vibration test of the muffler, an air tightness test shall be carried out at 200kPa air pressure for 1 minute. At this time, there shall be no air seepage in the shell, welding seams and curling edges of the muffler. 3.6 The muffler shall be subjected to a durability test in accordance with the provisions of Article 4.3.1. After the test, the muffler shall not have cracks, air leaks or abnormal sounds, and the reduction in insertion loss and increase in power loss ratio shall not be greater than 3dB(A) and 1% respectively. 3.7 "The stamping and welding parts of the muffler shall comply with the relevant standards or technical requirements. 3.8 According to the negotiation between the supply and demand parties, the exhaust port of the muffler can be equipped with a rain cap, fireproof and explosion-proof. 3.9 The surface of the material used for the muffler must be smooth and should not have defects such as rust or rot. 3.10 The parts of the muffler must be intact and should not have defects such as cracked keys, sharp edges, and bumps. 3.11 The outer surface of the muffler should be smooth and flat, and should be treated with anti-corrosion, such as high-temperature resistant paint, porcelain or aluminum spraying, etc. Aluminum-plated pot plates can also be used to manufacture the shell. Approved by the Ministry of Machinery and Electronics Industry on July 1, 1991 and implemented on July 1, 1992,
JB/T508191
3.12 During the warranty period of the diesel engine, the muffler shall not have cracks, air stagnation or abnormal sounds. The reduction in insertion loss and the increase in power loss ratio shall not be greater than 3dB(A) and 1% respectively. 4 Test methods
4.1 Test category
8. Performance test:
b. Reliability test
4.2 Performance test
Mufflers with new designs or major structural modifications, silencers newly matched with other types of diesel engines, and mufflers produced at transferred factories shall be subject to performance tests in accordance with the provisions of GB4759. 4.3 Feasibility test
Mufflers with new designs or major structural modifications, and mufflers produced at transferred factories shall be subject to performance tests in accordance with the provisions of GB4759. Reliability test. Reliability test consists of endurance test and vibration test. bzxZ.net
4.3.1 Endurance test
The muffler should be tested together with the diesel engine as a supporting machine. The test time shall be agreed upon by the supply and demand parties. 4.3.2 Vibration test
The muffler should be installed on a vibration table that can produce sinusoidal vibration in the vertical direction in the use (or close to use) state for vibration test. The vibration test consists of resonance test and endurance test. Note: 1 The vibration test location should be the muffler installation location, but when the safety rating is strong enough, the vibration can also be measured on the vibration platform. 4.3.2.1 Resonance test
The muffler should be tested according to the parameters specified in Table 2. To conduct a resonance test, first start the vibration of the muffler from an 8.3Hz perturbation frequency, and continuously increase the frequency to a 400Hz vibration frequency, and then continuously decrease the frequency of the muffler from a 400Hz perturbation frequency to a 8.3Hz vibration frequency to find the resonance frequency of the muffler.
Vibration frequency
Sweep cycle
Vibration acceleration
Note: T sweep cycle refers to the time required for the vibration frequency to change from 8.3Hz to 400Hz, and then from 400Hz back to 8.3Hz. ② If the perturbation acceleration and full amplitude are too large or too small, it is difficult to find the resonance, so here only the author, 4.3.2.2 Vibration resistance test
Full amplitude
0. 1~0. 4
After the resonance test of the muffler, the vibration resistance test shall be carried out according to Table 3 (muffler without resonance) or Table 4 (muffler with resonance). When the muffler has more than two resonance frequencies, its main resonance frequency shall be selected, Table 3
Vibration rate
Vibration acceleration
Vibration frequency
Resonance frequency
Vibration acceleration
JB/T5081--91
The instrument used for the vibration test of the muffler shall comply with the provisions of ZBY107. 4.3.2.3
5 Inspection rules
5.1 Inspection items
Appearance and installation dimensions;
Air tightness test:
Vibration test.
5.2 Product inspection rules
5.2.1 The sampling rules shall be agreed upon by the supply and demand parties in accordance with the relevant provisions of GB2828. 5.2.2 The judgment of whether a batch is qualified or unqualified shall be in accordance with the provisions of Article 4.12 of GB2828. 6 Marking, packaging, storage
The muffler shall have the name, model, manufacturer name, manufacturing date and other marks. 6.1
6.2 The muffler shall be placed in a packaging box, which shall be firm and lined with waterproof material. The product shall be separated in the box. The whole box shall be accompanied by the product manual, product certificate and packing list. 6.3 The outside of the packaging box should be marked with
Manufacturer name, trademark and address:
Product name and model:
Quantity:
Volume (length × width × height), mm;
Weight, kg;
Consignee and address:
Date of manufacture:
"Moisture-proof" "Handle with care\" and other signs
6.4 The muffler should be stored in a dry, ventilated warehouse free of corrosive substances. Under normal storage conditions, the manufacturer should ensure that the muffler will not rust within 12 months from the date of manufacture. Additional instructions:
This standard was proposed and managed by Shanghai Internal Combustion Engine Research Institute. This standard was drafted by Shanghai Internal Combustion Engine Research Institute. The main drafter of this standard is Sie Lanfang.
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