1、BRITISH STANDARD BS 6347-7: 1993 ISO 789-7: 1991 Performance assessment of agricultural tractors Part 7: Method for determination of axle power UDC 631.372.018:621.43.018BS6347-7:1993 This British Standard, having been prepared under the directionof the Agricultural Machinery and Implements Standard
2、s Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15 January 1993 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference AGE/6 Draft for comment 90/77277 DC ISBN 0 580 21601 2 Committees responsible for this
3、British Standard The preparation of this British Standard was entrusted by the Agricultural Machinery and Implements Standards Policy Committee (AGE/-) to Technical Committee AGE/6, upon which the following bodies were represented: Agricultural and Allied Workers National Trade Group Agricultural En
4、gineers Association British Agricultural and Garden Machinery Association Ltd. County Surveyors Society Department of Transport Forestry Commission Health and Safety Executive Local Authority Organizations Ministry of Agriculture, Fisheries and Food National Farmers Union Silsoe Research Institute U
5、nited Kingdom Softwood Sawmillers Association Coopted member Amendments issued since publication Amd. No. Date CommentsBS6347-7:1993 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Measurement units and t
6、olerances 1 5 General requirements 1 6 Test procedure 2 Annex A (normative) Specimen test report 4 Annex B (informative) Reference fuel CEC RF-01-80 for spark-ignition engines Specifications Premium gasoline leaded 8 Annex C (informative) Reference fuel CEC RF-03-A-84 for compression-ignition engine
7、s Specifications 9 Annex D (informative) Reference fuel CEC RF-08-A-85 for spark-ignition engines Specifications Premium gasoline unleaded 10 Annex E (informative) Bibliography 11 Table A.1 Table of results 7 List of references Inside back coverBS6347-7:1993 ii BSI 09-1999 National foreword This Par
8、t of BS 6347 has been prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee. It is identical with ISO789-7:1991 Agricultural tractors Test procedures Part7: Axle power determination published by the International Organization for Standardization (ISO).
9、ISO 789-7 was prepared by Subcommittee SC2, Common tests, of ISO Technical Committee23, Tractors and machinery for agriculture and forestry. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applica
10、tion. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard ISO 3448:1975 BS 4231:1982 Classification for viscosity grades of industrial liquid lubricants (Identical) ISO 4251-1:1988 BS AU
11、50 Tyres and wheels Part 1 Tyres Section 4 Agricultural tractor and machine types Subsection 4.1:1989 Specification for designation and dimensions for existing (inch) series tyres (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1to12, an
12、inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6347-7:1993 BSI 09-1999 1 1 Scope This International Standard specifies test procedures for dete
13、rmining the power available at the axle or axles of wheeled or track-laying agricultural tractors having one or two driven axles. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO789. At the time of publ
14、ication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part ofISO789 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of c
15、urrently valid International Standards. ISO 3448:1975, Industrial liquid lubricants ISO viscosity classification. ISO 4251-1:1988, Tyres and rims (existing series) for agricultural tractors and machines Part 1: Tyre designation and dimensions. 3 Definitions For the purposes of this part of ISO789, t
16、he following definitions apply. 3.1 rated engine speed engine speed specified by the tractor manufacturer for continuous operation at full load 3.2 axle power sum of the powers measured at all powered axles 3.3 maximum permissible torque maximum torque specified by the manufacturer for the purposes
17、of this test 3.4 specific fuel consumption mass of fuel consumed per unit of work 4 Measurement units and tolerances The following units and tolerances are used in this part of ISO789: a) rotational frequency, in revolutions per minute: 0,5% b) time, in seconds: 0,2s c) distance, in metres or millim
18、etres: 0,5% d) force, in newtons: 1% e) torque, in newton metres: 1% f) mass, in kilograms: 0,5% g) fuel consumption, in kilograms per kilowatt hour: 1% h) atmospheric pressure, in kilopascals: 0,2kPa i) temperature of fuels, etc., in degrees Celsius: 2 C j) wet and dry bulb thermometers, in degrees
19、Celsius: 0,5 C 5 General requirements 5.1 Specification The tractor tested shall conform to the specification in the test report (seeAnnex A) and shall be used in accordance with the manufacturers recommendations for normal operation. 5.2 Running-in and preliminary adjustments The tractor shall be r
20、un-in prior to the test. For spark-ignition engines fitted with a means for the operator to vary the ratio of the fuel/air mixture, the tests shall be carried out with the settings recommended for normal operation. The adjustment of the carburettor or the injection pump shall conform to the manufact
21、urers specification. Run-in shall be done with the governor set at full throttle and with the engine operating at rated speed. 5.3 Fuels and lubricants The compression-ignition (diesel) fuel used for the test shall comply with the CEC reference fuel CEC-RF-03-A-84. For spark-ignition engines, the te
22、st shall be carried out using CEC reference fuel CEC-RF-01-A-80 for premium leaded gasoline and CEC RF-08-A-85 for premium unleaded gasoline. (SeeAnnex B, Annex C andAnnex D, respectively.) The lubricants used for the test shall comply with the manufacturers specification and be identified by trade-
23、name, type, and viscosity class in accordance with ISO3448. If different lubricants are used, precise information shall be given as to where they are used (engine, transmission, etc.). If the lubricant conforms to other national or InternationalStandards, reference to these shall be made. 5.4 Ancill
24、ary equipment For all tests, accessories such as the hydraulic lift pump or air compressor may only be disconnected if it is practicable for the operator to do so as normal practice in work, in accordance with the operators manual and without using tools. If not, they shall remain connected and oper
25、ate at minimum load.BS6347-7:1993 2 BSI 09-1999 If the tractor is equipped with devices that create variable parasitic power losses such as a variable speed cooling fan, intermittent hydraulic or electrical demands, etc., the device shall not be disconnected or altered for test purposes. If it is pr
26、actical for the operator to disconnect the device as outlined by the operators manual, it may be disconnected for test purposes: this shall be recorded in the test report. Power variations during tests caused by these devices exceeding 5% shall be recorded in the test report in terms of percent vari
27、ation from the mean. 5.5 Operating conditions Make no corrections to the measured values of torque or power for atmospheric conditions or other factors. Atmospheric pressure shall not be less than96,6kPa. If this is not possible because of conditions of altitude, a modified carburettor or fuel pump
28、setting may have to be used, details of which shall be included in the report. The surrounding temperature shall be23 C 7 C. Stable operating conditions shall have been attained at each load setting before beginning test measurements. 5.6 Fuel consumption Arrange the fuel measurement apparatus so th
29、at the fuel pressure at the carburettor or the fuel injection pump is equivalent to that which exists when the tractor fuel tank is half-full. The fuel temperature shall be comparable to that occurring during full-load operation for2h of the tractor when fuel is taken from the tractor fuel tank. Whe
30、n consumption is measured by volume, calculate the mass of fuel per unit of work using the density corresponding to the appropriate fuel temperature. This figure shall then be used to calculate the volumetric data using the fuel density at15 C. Alternatively, when the consumption is measured by mass
31、, calculate volumetric data using the fuel density (specific gravity) value at15 C. 6 Test procedure 6.1 General All the driven axles of the tractor shall be coupled to the dynamometer. All measurements shall be made with the engine governor control set for maximum engine speed. The various tests sh
32、all normally be carried out continuously. The angularity of any shaft connecting the driving axles to the dynamometer shall not exceed2. If an exhaust gas discharge device for the test area is used, it shall not change the engine performance. 6.2 Choice of transmission ratios Measurements shall be m
33、ade in transmission ratios including and between that giving the slowest forward speed and that giving the fastest forward speed recommended by the manufacturer for field work, at between3km/h and16km/h. A minimum of six transmission ratios shall be used, their choice as far as possible allowing the
34、 efficiency of the various ratio-changing devices to be assessed. If the tractor has a hydrokinetic torque converter which can be locked out by the driver, carry out the test both with the torque converter in operation and with it locked out. If the tractor has a stepless variable transmission, carr
35、y out the test at six transmission ratios approximately equally spaced. Tractors with two drive axles shall be tested with both axles engaged. 6.3 Control of speeds and torques The torques applied and the rotational speeds of the two wheels of the same axle shall be equal. In the case of an axle whi
36、ch cannot be tested with the differential locked, the torques applied to each of the two wheels shall be controlled so that the deviation of the rotational speeds of the two wheels is less than5%. In the case of tractors with two driven axles with a differential between them which cannot be locked,
37、the torques applied to each of the two axles shall be controlled so that the deviation between the mean peripheral speeds of the front and rear wheels is less than5%. The dynamic radius indices of the tyres as defined inISO4251-1 shall be used for this determination. In the case of tractors with two
38、 drive axles without a differential between them, power at the axles shall be measured with several distributions of power between them. For each transmission ratio selected, increase the torque on the axle for which the manufacturer indicates the higher permissible torque until the rated engine spe
39、ed or the maximum torque permissible for the axle is reached. If the rated speed of the engine has not been reached, increase the torque on the second axle until the rated engine speed or the maximum torque permissible for this second axle is reached. If the rated speed of the engine has still not b
40、een reached, the measurement shall be terminated for that transmission ratio.BS6347-7:1993 BSI 09-1999 3 If the rated speed of the engine is reached, the measurement shall be repeated as many times as necessary to obtain the maximum torque permissible at the second axle by reducing the torque applie
41、d to the first axle each time by20% of the value applied to that axle in the first measurement. If the maximum torque permissible for the second axle is reached, increase the torque on the first axle to attain rated engine speed. For each measurement, record the rotational speed of each wheel, the t
42、orque applied to each wheel, the rotational speed of the engine and the fuel consumption. Also calculate the axle power. 6.4 Additional measurements In addition to the performance measurements specified above, report the following: a) ambient air temperature at a representative point approximately2m
43、 in front of the tractor and approximately1,5m above the ground (where the tractor is fitted with a forward blowing pusher fan, ambient air temperature measurements shall be made at appropriate alternative positions): b) air temperature at the engine air intake; c) atmospheric pressure; d) relative
44、air humidity; e) maximum coolant temperature (in case of an air-cooled engine, measure the temperature of the cylinder block at representative points); f) the fuel temperature at the inlet to the carburettor or injection pump; g) engine oil temperature; h) transmission oil temperature.BS6347-7:1993
45、4 BSI 09-1999 Annex A (normative) Specimen test report A.1 Locations A.2 Specification of tractorBS6347-7:1993 BSI 09-1999 5 Nominal travel speeds Gear Rear wheels Tyre size Dynamic radius index a Axle, r/min b Nominal travel speed, km/h b Front wheels (if powered) Tyre size Dynamic radius index a A
46、xle, r/min b Nominal travel speed, km/h b a See ISO4251-1. b At rated engine speed.BS6347-7:1993 6 BSI 09-1999 Masses (with tanks full but without driver) A.3 Fuel and lubricant specifications 1)RON: Research octane number Mass Front Rear Total Without ballast With ballastBS6347-7:1993 BSI 09-1999 7
47、 Table A.1 Table of results Fuel consumption hourly l/h NOTE Repeat this table if measurements are made in more than six transmission ratios. specific kg/kWh C % kPa Total power kW Atmospheric conditions Temperature: Relative humidity Pressure Front axle Power kW Right Speed r/min Torque Nm Left Spe
48、ed r/min Torque Nm Rear axle Power kW Date of test: Right Speed r/min Torque Nm Left Speed r/min Torque Nm GearBS6347-7:1993 8 BSI 09-1999 Annex B (informative) Reference fuel CEC RF-01-A-80 for spark-ignition engines Specifications Premium gasoline leaded Characteristic Limits and units Test method
49、 a Research octane number (RON) 98min. ISO 5164 Relative density 15 C/4 C (specific gravity) 0,748 0,007 ISO 3675 Reid vapour pressure 60kPa 4kPa(600mbar 40mbar) ISO 3007 Distillation ISO 3405 Initial boiling point 32 C 8 C 10% (volume) 50 C 8 C 50% (volume) 100 C 10 C 90% (volume) 160 C 10 C Final boiling point 195 C 10 C Residue 2% (V/V)max. Hydrocarbon analysis ISO 3837 Olefins 20%(V/V)max. Aromatics 45%(V/V)max. Saturates balance Oxidation stability 480minutesmin. I
