JB/T 7297-1994 Diesel engine fuel injection nozzle assembly performance test method JB/T7297-1994 standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7297-94
Diesel Engine Injection Nozzle Pairs
Published on July 18, 1994
Performance Test Methods
Implemented on July 1, 1995
Ministry of Machinery Industry of the People's Republic of China
Mechanical Industry Standard of the People's Republic of China
Diesel Engine Injection Nozzle Pairs
1 Subject Content and Scope of Application
Performance Test Methods
JB/T729794
This standard specifies the performance test methods for medium and small power diesel engine injection nozzle pairs (hereinafter referred to as injection nozzle pairs). This standard applies to medium and small power diesel engine injection nozzle pairs. 2 Reference standards
GB1958
GB6810
GB8029
JB/T7296
ZBJ94016
3 Test methods
Light diesel
Shape and position tolerance test regulations
Diesel engine fuel injection pump test bench High pressure oil pipe assembly Diesel engine fuel injection pump calibration oil
Diesel engine fuel injection nozzle assembly Technical conditions
Fuel injection pump test bench Technical conditions
3.1 The shapes of the items in this standard The shape and position tolerances shall be tested in accordance with GB1958, except for special provisions. 3.2 The surface roughness of the needle valve body and the needle valve sealing cone surface is allowed to be compared with standard samples. 3.3 Cleanliness test
After carefully cleaning and lubricating the parts with well-filtered No. 0 light diesel oil that meets the requirements of GB252, place the injection nozzle at a 45° angle to the horizontal, and pull out the needle from the needle valve body by one-third of the length of the cylindrical working surface. The needle rotates around its own axis to any position. After releasing it, the needle can slide down and fall into the seat by its own weight without any obstruction. 3.4 Diameter sealing test
3.4.1 This test is carried out on a diameter sealing test bench equipped with a pressure display device (accuracy ±0.5%, range 0~40MPa) and a high-pressure oil circuit volume of 10cm (excluding the internal volume of the pressure gauge). 3.4.2 The ambient temperature is 20±1℃.
3.4.3 The test oil is a mixture of diesel and engine oil, and its kinematic viscosity at 20°C is 10.2~10.7mm*/s. 3.4.4 The sealing requirements of the test bench: the test oil pressure rises to 32MPa, and starts timing when it drops to 30MPa. The pressure drop within 3 minutes should not exceed 1MPe.
3.4.5 When the test oil enters from the gap of the nozzle pair, the sealing end face of the needle body and the contact surface of the fixture should be sealed, and oil leakage is not allowed.
3.4.6 During the test, the test oil pressure should start timing when it drops from 23~24MPa to 20MPa, and end timing when it drops to 18MPa.
3.4.7 The diameter sealing test can be carried out by the sample comparison method. In this case, the temperature and viscosity of the test oil used are not specified; other oil pressure or gas flow test methods can also be used, but the standard sample must meet the sample quality requirements specified in Article 3.10 of JB/T7296. 3.5 Spray and sealing cone sealing test
3.5.1 The spray and sealing cone sealing test of the nozzle pair is carried out on a pressure storage cylinder (volume is about 2500cm) and a ticket test bench.
Approved by the Ministry of Machinery Industry on July 18, 1994
Implemented on July 1, 1995
3.5.2 The ambient temperature is 23±5℃.
JB/T 729794
3.5.3 The test oil should meet the requirements of No. 0 light diesel oil specified in GB252. 3.5.4 During the test, adjust the injection pressure of the fuel injection nozzle to the opening pressure when used on the diesel engine, and spray at a frequency of 60 to 80 times/min. At this time, check the spray quality and surface sealing: the spray quality should meet the requirements of Article 3.12 of JB/T7296. a.
b. Surface tightness requires that after the start and end of the injection, there should be no oil accumulation on the end face or head of the needle body (the fuel injection nozzle is in a vertical position). www.bzxz.net
3.5.5 The sealing of the nozzle and sealing surface can also be carried out on the hand pump test bench, and its inspection quality should meet the requirements of the above-mentioned machine pump test bench.
3.6 Flow test
The flow test of the fuel injection nozzle pair should be carried out on the fuel injection ticket test bench using the same ticket of the fuel injection case. 3.6.1 The test oil should meet the requirements of No. 0 light diesel oil specified in GB252 or the calibration pump oil specified in GB8029. 3.6.2 The high-pressure oil pipe used in the test bench shall comply with the provisions of GB6810, and the injection ticket test bench shall comply with the provisions of ZBJ94016. 3.6.3 The opening pressure of the needle valve shall be adjusted according to the requirements of the diesel engine it is equipped with. The flow test of the nozzle pair can also be carried out on the normal pressure flow test bench, and its flow deviation rate shall be in accordance with the technical agreement between the manufacturer and the user. 3.7 Reliability test
The reliability test method of the nozzle pair is carried out in Appendix A (Supplement). 2
A1 Test sample
JB/T 729794
Appendix A
Reliability test method of the nozzle pair
(Supplement)
A1.1 The nozzle pair for reliability test shall comply with the provisions of the product drawings and relevant technical documents, and shall be inspected and qualified by the factory inspection department.
A1.2 Sampling at the factory warehouse or the end of the production line, the sample matrix shall not be less than 90 pairs; sampling at users and the market, the sample matrix is ​​not limited. A1.3 Randomly sample 8 pieces, all of which are subjected to reliability tests. A2 Test method
A2.1 The reliability test of the nozzle pair is to install it in the injector and cold drag it on the indoor bench; in order to shorten the test time, the indoor bench can be used for rapid cold drag. The rapid test adopts the method of speeding up the injection frequency while ensuring the correct injection. A2.2 When testing with the injection pump, the speed is based on the injection pump speed: During the rapid test, the speed of the injection pump used in the reliability test bench is controlled at 1000±20r/min.
A2.3 The test oil should be the light diesel oil No. 0 specified in GB252. A2.4 The test oil temperature should be controlled at 40 ± 5℃. A2.5 The test condition is to select the fuel injection amount of the diesel engine equipped with the product at 120% rated power as the test condition. A2.6 The reliability assessment of the fuel injection coupling is carried out in a timed tailing manner. The test time is determined according to the acceleration factor K. However, it must be guaranteed to be equivalent to 6×10° working cycles (cold drag). A3 Failure judgment
During the test, 5 tests must be carried out at equal time intervals. 43.1 If the fuel injection nozzle is damaged during the test, it is judged as a failure and the test of the failed sample is stopped. A3.2 During the test, the inspection items are 3.8, 3.9, 3.10, and 3.11 in JB/T7296. The inspection method is in accordance with the corresponding provisions of this standard. If the failure items listed in Table A1 appear, the test of the sample is stopped and the occurrence time t is recorded. Table A1 Examples of failure of fuel injection nozzle components
Similar items
Fuel injection nozzle cracking
Needle valve stuck
Fuel injection not atomized
Poor spray quality
Poor sealing of seat surface
Tested according to the requirements of this standard, fuel injection is not atomized
Tested according to the requirements of this standard, spray deviation, continuous oil column and easily distinguishable local uneven concentration appear
Obvious oil dripping at the nozzle
Note: If a failure not listed in this table occurs, refer to the classification period in the above table to determine A4 Failure occurrence time
A4.1 For failures that can be discovered in time, record its exact occurrence time. A4.2 For failures that cannot be discovered in time, determine its occurrence time T according to formula (A1). It is known that n faults occur within the time interval Et-1, then the time when the mth fault occurs is: 3
Additional explanation:
JB/T 7297~94
Tm= th 1
This standard is proposed and managed by Wuxi Oil Pump and Nozzle Research Institute of the Ministry of Machinery Industry. ...(A1)
This standard was drafted by Wuxi Oil Ticket and Nozzle Research Institute and Shanghai Internal Combustion Engine Research Institute. Wuxi Oil Pump and Nozzle Factory, Shanghai Diesel Engine Factory Oil Pump Branch, Luoyang First Tractor Factory Oil Pump Branch and other units participated in the drafting.
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