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 2017 SAE International All rights reserved. No part of this
3、publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-49
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:/standards.sae.org/J820_201706 SURFACE VEHICLE RECOMMENDED PRACTICE J820 JUN2017 Issued 1962-04 Reaffirmed 1998-0
5、7 Revised 2017-06 Superseding J820 JUL1998 Crane Hoist Line Speed and Power Test Procedure RATIONALE Adding a sentence to the SCOPE defining the various types of hoist mechanisms, and the re-write of 6.2 improves the intent of this document. 1. SCOPE This document applies primarily to mobile cranes
6、that lift loads by means of a drum and hoist line mechanism. It can be used to determine the hoist line speed and power of other hoist line mechanisms, if the load can be held constant and hoist line travel distance is sufficient for the accuracy of the line speed measurements prescribed. This recom
7、mended practice applies to all mechanical, hydraulic, and electric powered hoist mechanisms. 1.1 Object The object of this test is to determine the hoist line speed that a mobile crane develops while hoisting a specified load with a specified condition of rope layers on the drum. The specified load
8、is reported in pounds and the hoist line speed in feet per minute. Values derived may be used to calculate hoist line power. 2. REFERENCES There are no referenced publications specified herein. 3. DEFINITIONS 3.1 SPECIFIED Recommendations or requirements stated by the manufacturer, the user, the tes
9、ting agency, or any agreement between these parties. 3.2 HOIST LINE A wire rope or similar line that operates in conjunction with sheaves and a drum, for the purpose of lifting and supporting loads. SAE INTERNATIONAL J820 JUN2017 Page 2 of 5 3.3 HOIST LINE POWER A rate of doing work, derived by math
10、ematically correlating measured values of time, distance, and force; normally expressed as horsepower or foot pounds per unit time. 3.4 LOAD The weight in pounds of the hook block and other items suspended from the hook block, as arranged to make up the specified load weight. 4. LIMITATIONS 4.1 It i
11、s important that the manufacturers maximum load recommendations for the conditions of test not be exceeded, since such loads are frequently based on structure or stability limitations. 4.2 Hoist mechanisms on mobile cranes are usually powered by internal combustion engines. Such engines are affected
12、 in performance by the atmospheric conditions of temperature, humidity, and altitude. For this reason, and because engine and hoisting mechanism friction is indeterminate, the values measured are reported as observed. Reliable correction factors for the influence of atmospheric conditions and mechan
13、ism friction are not available; hence the results of test may be compared with other tests, only if such tests are conducted under identical atmospheric conditions. 5. FACILITIES, APPARATUS, AND MATERIALS 5.1 Tachometer of range suitable to indicate engine speed; accuracy 1% of rpm measured. 5.2 Mea
14、ns for weighing test weights, hook block, slings, and other load components; accuracy 0.5% of the weight measured. 5.3 Test weights or other loading means as required to make up the specified load within 0.5% of the total weight specified. 5.4 Means to measure and record: a. Line travel distance; ac
15、curacy 1% of measured value b. Line travel time; accuracy 1% of measured value c. Load line force; accuracy 2% of values recorded throughout range of values measured 6. PROCEDURE 6.1 Service and adjust the machine to be tested in accordance with the manufacturers instructions. 6.2 Operate the machin
16、e under partial load to ensure operator proficiency and proper machine function. New machines should be operated a minimum of 4 hours to ensure proper function. Inspect, adjust, and service the machine as specified by the manufacturer at the conclusion of the initial operation. Inspect and maintain
17、adjustments after the machine is operated to assure that the engine, clutches, brakes, and other power transmitting components remain within the manufacturers recommended tolerances. 6.3 Assemble a test load as specified. 6.4 Arrange the hoisting tackle on the machine in accordance with the manufact
18、urers instructions, using the minimum parts of hoist line necessary to assure safe and smooth operating while hoisting the specified load. NOTE: It is desirable to use a single part line in order to reduce tackle friction; however, safety and load travel distance may dictate need for multiple part l
19、ines. SAE INTERNATIONAL J820 JUN2017 Page 3 of 5 6.5 Attach the specified load to the hoist line and install line speed and force sensing and recording instruments. 6.6 Perform sufficient trial runs of hoisting the specified load to assure that: a. The machine operator is familiar with procedure of
20、operation. b. The machine is warmed up to normal operating temperatures. c. The instruments are functioning properly. 6.7 With the engine operating at full throttle smoothly engage the hoist and lift the load. While the load is being lifted, measure and record: a. Hoisting force b. Hoist line travel
21、 distance c. Time Repeat this operation to obtain a total of five recorded runs. 7. COMPUTATIONS AND RECORDS 7.1 For each test run, calculate the average hoist line speed, using only that portion of the records where the recorded hoisting force remains constant within 2% of average. Record the avera
22、ge speed and load value for each recorded run on the test summary sheet. (See Figure 1.) 7.2 Calculate the hoist line power in horsepower for each recorded run as shown in Equation 1: (Eq. 1) where: L = load (lb) S = line Speed (fpm) P = number of parts in the hoist line Record these values on the t
23、est summary sheet (see Figure 1). 7.3 Calculate the average hoist line power for all recorded runs and record this value on the test summary sheet. NOTE: Wherein the horsepower for any individual run deviates more than 2% from the arithmetic mean for all runs, a determination should be made of reaso
24、ns for erratic performance, the data discarded, and the test rerun. HPLS33 000 P-=SAE INTERNATIONAL J820 JUN2017 Page 4 of 5 Figure 1 - Test data summary sheet SAE INTERNATIONAL J820 JUN2017 Page 5 of 5 8. NOTES 8.1 Revision Indicator A change bar (l) located in the left margin is for the convenienc
25、e of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE CRANES AND LIFTING DEVICES COMMITTEE
