1、 _ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising ther
2、efrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2016 SAE International All rights reserved. No part of this
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4、70 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1668_201605 SURFACE VEHICLE STANDARD J1668 MAY2016 Issued 1993-06 Reaffirmed 19
5、99-04 Revised 2016-05Superseding J1668 APR1999 Diesel Engines - Fuel Injection Pump Testing RATIONALE Editorial change to correct the number and title of the ANSI standard cited in clause 2.1.2. 1. SCOPE The correct setting and adjustment of fuel injection pumps requires standardized testing conditi
6、ons. This SAE Standard summarizes the design and operating parameters for test benches so that, using certain information supplied by the pump manufacturer, the pump test schedule, and certain information supplied by the test bench manufacturer, it can be determined whether a particular test bench i
7、s suitable for driving a particular injection pump. This document is in most cases a summary of the ISO Standard 4008, Parts 1, 2, and 3 and is intended to provide its critical aspects. Standard ISO 4008 should be referred to for more details. 1.1 Field of Application This document is primarily appl
8、icable to test benches suitable for the calibration of fuel injection pumps for diesel engines requiring a fuel delivery of up to 300 mm3/st/cylinder at full load. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of the specification to the extent specified herein. Un
9、less otherwise indicated the latest revision of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J967 Calibration Fluid SAE J968 Calibrating Nozzle and Holder Assemblies SAE J1549 Diesel Fuel Injection PumpValidation of C
10、alibrating Nozzle Holder Assemblies SAE INTERNATIONAL J1668 MAY2016 Page 2 of 17 2.1.2 ANSI Publication Available from ANSI, 11 West 42nd Street, New York, NY 10036-8002. ANSI/ASME B40.100 Pressure Gauges and Gauge Attachments 2.1.3 ISO Publications Available from ANSI, 11 West 42nd Street, New York
11、, NY 10036-8002. ISO 4008Part 1 Fuel injection pump testingDynamic conditions ISO 4008Part 2 Fuel injection pump testingStatic conditions ISO 4008Part 3 Fuel injection pump testingApplication and test procedures ISO 4020-2 Fuel filters for automotive compression-ignition enginesPart 2, Test values a
12、nd classification ISO 8984 Testing of fuel injectors for compression-ignition engines 2.2 Other Publications “Fuel Injection and Controls,“ 1962 by P. Burman and F. De Luca 3. DYNAMIC TIMING 3.1 Speed Variation at Constant Load The mean speed of the driveshaft under any steady admissible load shall
13、not vary more than 1/4% above 800 rpm and 2 rpm below 800 rpm for at least 1 min. 3.2 Flywheel Inertia The test bench flywheel shall ensure that the instantaneous speed drop of a pump during injection (i.e., cyclic speed variation) shall be less than 1% at any critical calibration point. Based on th
14、is criterion, the required flywheel inertia can be calculated from Equations 1 and 2: (Eq. 1)or (Eq. 2) where: I = Moment of inertia (kgm2) Qmax = Pump delivery at calibration point (mm3/st/outlet) ppa = Peak Line Pressure (bar) n = Pump Test Speed (rpm) IQmaxppau1.31 n2u-=Qmaxln21.31uuppa-=SAE INTE
15、RNATIONAL J1668 MAY2016 Page 3 of 17 To prevent torsional resonance with other mass in the transmission, the flywheel shall be as close to the coupling output as possible. 3.3 Driveshaft Stiffness The maximum instantaneous angular driveshaft deflection under any operating conditions shall be 0.02 de
16、grees. The required driveshaft stiffness is calculated as shown in Equation 3: (Eq. 3)where: Sd = Driveshaft Stiffness (Nm/) Qmax = Maximum pump delivery (mm3/st/outlet) ppa = Peak Line Pressure (bar) The driveshaft is considered to be the part connecting the flywheel to the test bench coupling. (On
17、 some test benches there is no driveshaft because the coupling is mounted directly to the flywheel). 3.4 Coupling Stiffness The maximum instantaneous angular deflection of the drive coupling under operating conditions shall be 0.1 degree. The required coupling stiffness is given by Equation 4: (Eq.
18、4)where: Sc = Coupling Stiffness (Nm/) Qmax = Maximum pump delivery (mm3/st/outlet) ppa = Peak Line Pressure (bar) In Equations 1 to 4, it is assumed that the mean injection pressure is represented by a sine wave and the injection duration is 10 degrees of pump rotation. 3.5 Pump Mounting Stiffness
19、and Alignment The injection pump mounting shall be stiff enough to ensure that deflection of the pump body flange (or base bracket) about its driveshaft is less than 0.02 degree with respect to ground during injection. Special apparatus to measure pump mounting stiffness is fully described in ISO 40
20、08 Part 1. In addition, the pump mounting shall align the pump driveshaft with the test bench output within 0.13 mm radially and 0.05 degree angularly (or 0.25 mm over 300 mm length). SdQmaxppau22.4-=ScQmaxppau125.6-=SAE INTERNATIONAL J1668 MAY2016 Page 4 of 17 3.6 Backlash There shall be no backlas
21、h between the flywheel and the pump drive coupling. 3.7 Angular Creep There shall be no angular movement between connecting parts situated between the flywheel and the pump drive coupling when subject to torque reversals equal to twice the peak injection torque according to Equation 5: (Eq. 5)where:
22、 T = Peak injection torque (Nm) Qmax = Numeric value of pump max delivery The formulae for driveshaft and coupling stiffness as well as limits for pump mounting stiffness and angular creep were derived during extensive testing. 3.8 Power Output Test bench power output may be significantly less than
23、the drive motor rated power and is not constant through the speed range. It depends on the type of transmission used. Therefore, output power shall be checked using a dynamometer connected to the test bench driveshaft, and results plotted on a graph as shown in Figure 1. Speed droop (no load to full
24、 load) if any, and speed variation at constant load over 1 min shall also be measured using a dynamometer. 3.9 Conditions In order to meet 3.2, 3.3, 3.4, 3.5, and 3.8 of this part of the Standard, the test bench manufacturer and the injection pump manufacturer must provide information to the user to
25、 enable him to determine the suitability of a certain test bench to test and calibrate a specific injection pump. a. Test bench manufacturer shall publish 1. Continuous horsepower at the drive coupling available to drive the injection pump. This should be presented in the form of a graph as shown in
26、 Figure 1. If maximum horsepower is given, then maximum duration, ambient temperature, or other conditions and limitations must be stated. 2. Flywheel moment of inertia (kgm2) 3. Coupling stiffness (Nm/) 4. Driveshaft stiffness (Nm/) 5. Flange and/or base bracket stiffness (Nm/) Furthermore, the tes
27、t bench manufacturer shall provide a graph showing the permissible operating envelope based on formulae given in 3.2, 3.3, and 3.4. For simplicity, a peak injection pressure of 628 bar is assumed for this graph. If actual peak pressure is not 628 bar, then fuel delivery must be corrected as describe
28、d in 3.10 in order to use the graph. An example of the graph is shown in Figure 2. (If the curve showing the stiffness of the flange or base brackets lies outside of the permissible operating envelope, it does not have to be shown in the graph.) TQmaxtSAE INTERNATIONAL J1668 MAY2016 Page 5 of 17 b.
29、Injection pump manufacturer shall publish 1. Maximum horsepower that the injection pump absorbs 2. Fuel delivery (mm3/stroke) 3. Peak injection pressure (bar) at each critical test point in the pump specification. FIGURE 1 - POWER CURVE SAMPLE SAE INTERNATIONAL J1668 MAY2016 Page 6 of 17 FIGURE 2 -
30、PERMISSIBLE OPERATING ENVELOPE If horsepower is not specified, it can be approximated by Equation 61: (Eq. 6) where: HP =Horsepower (kW) Ppa =Peak injection pressure (bar) Q =Fuel delivery (including retraction volume) (mm3/st) n =Number of injections per minute K =0.75 (accounting for pump efficien
31、cy and effect of retraction volume) 3.10 Application and Use of Given Information Assume a 6-cylinder pump delivers 180 mm3/st at 600 rpm with a peak injection pressure of 800 bar. a. Step 1Determine Corrected Fuel DeliveryFrom Figure 3, correction factor at 800 bar is 1.27 (800/628). Therefore, the
32、 corrected delivery will be 1.27 x 180 = 228.6 mm3/st. b. Step 2Plot the point on the graph (Figure 2) where the corrected delivery (228.6 mm3/st) intersects the speed (600 rpm). This must be within the operating envelope of the test bench (shaded area in Figure 2). c. Step 3Calculate power requirem
33、ent. 1Reference: Derived from a formula given in “Fuel Injection and Controls.“ HPppaQnu 1.66 109uuuK-=SAE INTERNATIONAL J1668 MAY2016 Page 7 of 17 If not given by the pump manufacturer, calculate HP from Equation 6. In this case see Equation 7: (Eq. 7) Plot this point on graph (Figure 1). It must l
34、ie below the dotted curved line for the test stand to be capable of running this particular pump. FIGURE 3 - CORRECTION FACTOR FOR PEAK INJECTION PRESSURE HP800 180u 3600u 1.66u 109u0.75-=SAE INTERNATIONAL J1668 MAY2016 Page 8 of 17 4. STATIC REQUIREMENTS 4.1 Delivery Measurement System The calibrat
35、ion fluid delivered from each test injector shall be routed to the device for measuring delivery and displaying it directly or by simple calculation as an average expressed in cubic millimeters per stroke per outlet. There shall be provision for observing visually, or by other suitable means, the mo
36、ment when flow from any of the test injectors stops. 4.1.1 Method of Testing the Pump Delivery Measurement System Each test bench make and model shall pass the acceptance test. This test shall consist of: a. Type TestTo be performed on at least one sample test bench and is aimed at proving the capab
37、ility of a design to achieve the desired accuracy; a sophisticated apparatus is required. Allowable error shall not exceed 1% if no specific instructions are given by the test stand manufacturer regarding graduate selection or stroke count; error shall not exceed 2% if instructions are given. b. Fie
38、ld TestTo be performed periodically in the field on all test benches to ensure continued satisfactory operation; this test requires no special apparatus. Graduate zero error shall not exceed 0.5% of its maximum capacity. Count error shall not exceed one turn. The complete test procedure for the Type
39、 and Field Tests are found in ISO 4008, Part 2, Annex A. An alternate and equally acceptable Type Test by weight method is described in Appendix A. If graduates are used, the minimum pitch of graduations shall be at least 1 mm. One graduation shall not be greater than 1% of the total volume. A certa
40、in number of graduations from zero upwards may be omitted. If a digital display is used, then, at a minimum, fuel delivery shall be displayed in mm3/st with a resolution of 0.1 mm3/st. 4.2 Calibration Fluid System The calibration fluid supply shall be at a flowrate of at least 2.5 times the delivery
41、 flow rate from the pump under test. At any supply pressure over 0.3 bar, the maximum pressure fluctuation (from peak to peak) shall be no more than 5% of the reading with the supply connection capped off. Calibration fluid temperature, as measured immediately behind the bulkhead supply connection,
42、must be held to 40 C 2 C, irrespective of the pump demand. The supply pipe shall be 1 m + 0.1 m long with an inside diameter of at least 9.5 mm. a. Temperature measuring accuracy: 0.5 C 40 C b. Filtration: according to ISO 4020-2 c. Calibration fluid heater, if installed, shall be designed so as not
43、 to cause breakdown of the fluid 4.3 Other Requirements SAE INTERNATIONAL J1668 MAY2016 Page 9 of 17 4.3.1 Pressure and Vacuum Measuring Instruments a. Accuracy: ANSI/ASME B40.1-1985 Grade A (2-1-2% FS) or better 4.3.2 Driveshaft Tachometer a. Analog: Not acceptable b. Digital: Resolution 1 rpm c. A
44、ccuracy: 1 digit 4.3.3 Output Shaft Angular Measuring Arrangement a. Resolution of angular readout: 1 degree max b. Error between any two divisions: 15 min max c. Datum mark shall not produce parallax error 5. APPLICATION AND EQUIPMENT MAINTENANCE RECOMMENDATIONS 5.1 Test Benches When a statement of
45、 ISO Test Condition is requested it shall conform with Annex E to ISO 4008, Part 3. 5.2 Test Injectors All calibrating nozzle and holder assemblies conforming to the appropriate Standard must be accompanied by documentation (marking or labels in packaging) supplied by the manufacturer and vouching f
46、or their conformance to the document. Other test injectors and nozzles may be specified in the appropriate pump test specifications. For purposes of maintenance, a record shall be kept of the number of pumps tested with each test injector set. For calibrating nozzle and holder assemblies and test in
47、jectors maintenance and servicing schedules, refer to Appendix B. It gives information on frequency of maintenance, testing procedure, recommended settings and limits for opening pressures, seat leakage, back leakage, and tightening torque values for nozzle retaining nuts and edge filter assembly (i
48、nlet studs). 5.3 Testing 5.3.1 Test Schedule The test schedule shall contain all the necessary information and instructions necessary to set and test the pump in the field service environment. It does not override a test bench manufacturers instruction regarding a specific calibration system (for example, graduate drainage time, number of strokes over which to take a measurement, etc.). SAE INTERNATIONAL J1668 MAY2016 P
