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 there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2008 SAE International All rights reserved. No part of this publication m
3、ay 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: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org ARP490F AEROSPACE RECOMMENDED PRACTICE Issued 1958-07 Revised 2008-02 Superseding ARP490E (R) Electrohydraulic Servovalves RATIONALE This revision of SAE ARP490 document is a result of a scheduled periodic document r
5、eview. It incorporates changes recommended by the SAE A-6 Panel and committee members. TABLE OF CONTENTS 1. SCOPE.3 2. REFERENCES.3 2.1 Applicable Documents .3 2.1.1 SAE Publications3 2.1.2 Non-Government Publications: Available from various commercial sources.3 2.1.3 U.S. Government Publications.4
6、2.2 Definitions 4 2.2.1 General 4 2.2.2 Electrical Characteristics4 2.2.3 Steady State Characteristics5 2.2.4 Dynamic Performance Characteristics 14 2.3 Symbols and Abbreviations .14 3. PROCUREMENT SPECIFICATIONS15 3.1 Introduction 15 3.1.1 Numbering System.15 3.1.2 Valve Sizes 15 3.1.3 Valve Varian
7、ts15 3.1.4 Tolerances .15 3.2 Specification Considerations16 3.2.1 Scope (1.).16 3.2.2 Reference Documents (2.).16 3.2.3 Requirements (3.) 16 3.2.4 Quality Assurance Considerations (4.) 32 4. RECOMMENDED TEST METHODS.35 4.1 General 35 4.2 Test Equipment35 4.3 Electrical Tests.40 4.3.1 Insulation Res
8、istance and Dielectric Strength .40 4.3.2 Coil Resistance 40 4.3.3 Coil Impedance 41 4.4 Steady State Performance Tests.41 4.4.1 Polarity .41 4.4.2 Proof Pressure and External Leakage.41 4.4.3 Flow Curve .42 4.4.4 Lap .43 Copyright SAE International Provided by IHS under license with SAENot for Resa
9、leNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 2 - 4.4.5 Threshold .43 4.4.6 Internal Leakage 43 4.4.7 Pressure Gain 43 4.4.8 Null Pressure44 4.5 Dynamic Response Tests44 4.5.1 Test Circuit Considerations (See Figure 16)44 4.5.2 Conditions of Measureme
10、nt.44 4.5.3 Performance of Test: .44 4.6 Use of Overlays44 4.7 Environmental Tests 50 4.7.1 Temperature.50 4.7.2 Altitude .50 4.7.3 Vibration .51 4.7.4 Sustained Acceleration 51 4.7.5 Shock .51 4.7.6 Humidity .51 4.7.7 Salt Spray.52 4.7.8 Fungus Resistance 52 4.7.9 Fluid Contamination .52 4.7.10 Lif
11、e52 5. QUALITY ASSURANCE AND RELIABILITY CONSIDERATIONS .53 5.1 Quality Assurance Considerations.53 5.1.1 Scope .53 5.1.2 Contamination Control .53 5.1.3 Test Equipment and Gaging Calibration Tolerance.54 5.2 Reliability54 5.2.1 Scope .54 5.2.2 Considerations .54 5.2.3 Numerical Reliability Requirem
12、ents.55 5.2.4 Reliability Program Requirements .55 5.2.5 Reliability Test55 5.2.6 Reliability Prediction.55 6. NOTES.56 APPENDIX A SAMPLE SPECIFICATION: SERVOVALVE, ELECTROHYDRAULIC FLOW-CONTROL.57 APPENDIX B PRESSURE CONTROL SERVOVALVE TERMINOLOGY .72 FIGURE 1 COIL IMPEDANCE AMPLITUDE AND PHASE ANG
13、LE .6 FIGURE 2 FLOW CURVE .7 FIGURE 3 NORMAL FLOW CURVE.8 FIGURE 4 OPERATING REGIONS 9 FIGURE 5 LINEARITY/SYMMETRY .10 FIGURE 6 PRESSURE GAIN12 FIGURE 7 LAP DEFINITIONS.13 FIGURE 8 STANDARD ENVELOPES 18 FIGURE 9 STANDARD MOUNTING INTERFACES.19 FIGURE 10 STANDARD COIL CONNECTIONS 24 FIGURE 11 NULL RE
14、GION CONTROL PRESSURE, UNLOADED FLOW CONDITION30 FIGURE 12 FLOW CURVE EQUIPMENT SCHEMATIC 36 FIGURE 13 INTERNAL LEAKAGE EQUIPMENT SCHEMATIC.37 FIGURE 14 PRESSURE GAIN EQUIPMENT SCHEMATIC.38 FIGURE 15 SERVOVALVE COIL IMPEDANCE TEST.39 FIGURE 16 FREQUENCY RESPONSE TEST EQUIPMENT.45 FIGURE 17 SAMPLE OV
15、ERLAY.47 TABLE 1 RATED FLOWS FOR STANDARD VALVE SIZES .17 TABLE 2 INTERCONNECTED CYLINDER PORT PRESSURE 31 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 3 - 1. SCOPE This SA
16、E Aerospace Recommended Practice (ARP) provides definitions and background information for understanding the physical performance, and test procedures of electrohydraulic flow control servovalves. The recommendations are confined to interface definition and input/output characteristics. This ARP doe
17、s not restrict or attempt to define the internal characteristics of servovalves. As such, the recommendations are equally applicable to valves having different internal functioning, different ratings, different physical size, and valves used with different fluids. In certain instances, standards for
18、 valve design are recommended for the purpose of interchangeability, as for example, valve polarity, mounting bolt and fluid port locations. The ARP provides extensive guidance for the preparation of Procurement Specifications and for functional testing. A sample Procurement Specification is provide
19、d in Appendix A. The primary focus of this ARP is on four-way valves. Three-way valves are discussed to a limited extent and terminology for pressure control valves is presented in Appendix B. This ARP is applicable to fluid power systems in all types of flight vehicles, and it is applicable to Mili
20、tary, Civil and Space design/certification standards. Additional specifications or specialized test procedures may be necessary to define special requirements for specific control systems, and such considerations are beyond the scope of this ARP. 2. REFERENCES 2.1 Applicable Documents The following
21、publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and refere
22、nces cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel:
23、 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AIR810 Degradation Limits of Hydrocarbon-Based Hydraulic Fluids, MIL-H-5606, MIL-H-6083, MIL-H-83282, and MIL-H-46170 Used in Hydraulic Test Stands ARP1231 Gland Design, Elastomeric O-Ring Seals, General Considerations
24、 AS1241 Fire Resistant Phosphate Ester Hydraulic Fluid for Aircraft ARP1383 Impulse Testing of Aerospace Hydraulic Actuators, Valves, Pressure Containers, and Similar Fluid System Components AS4059 Aerospace Fluid Power - Cleanliness Classification for Hydraulic Fluids 2.1.2 Non-Government Publicati
25、ons: Available from various commercial sources. NHB 5300.4 Reliability Program Provisions for Aeronautical and Space System Contractors NASM33540 Safety Wiring and Cotter Pinning, General Practices for ANSI/NCSL Z540-1 General Requirements for Calibration Laboratories and Measuring and Test Equipmen
26、t RTCA DO-160 Environmental Conditions and Test Procedures for Airborne Equipment Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 4 - 2.1.3 U.S. Government Publications Availa
27、ble from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. MIL-PRF-83282 Hydraulic Fluid, Fire Resistant Synthetic Hydrocarbon Base, Aircraft, Metric, NATO Code Number H-537
28、 MIL-PRF-87257 Hydraulic Fluid, Fire Resistant; Low Temperature, Synthetic Hydrocarbon Base, Aircraft however, three-way servo-valves should use the same basic mountings and dimensions except that one control port should be eliminated. The flow capacity of commercially available servovalves most fre
29、quently employed may be classified broadly in terms of their respective port pattern dimensions as shown in Table 1. It is not essential that these maximum ratings be rigidly followed since the allowable pressure drop within the servovalve at maximum required flow, or interchangeability requirements
30、, often dictate the mounting configuration to be employed. TABLE 1 - RATED FLOWS FOR STANDARD VALVE SIZES Size Flow1gpm (mL/s) IA IB II III IV 0.480 in x 0.300 in (12.19 mm x 7.62 mm) 0.480 in ( 12.19 mm) 0.625 in ( 15.88 mm) 0.780 in ( 19.81 mm) 1.000 in ( 25.40 mm) 2 (125) 2 (125) 6 (375) 15 (950
31、30 (1890) 1Maximum no-load flow at 3000 psid (20 000 kPa) using MIL-PRF-83282 fluid at 100 F (38 C). For alternate fluids and pressures, the applicable maximum flow can be estimated as: Q = (Q/6210) x (P/)1/2where: Q = Maximum flow, per the preceding table Q = New maximum flow P = Valve pressure dro
32、p, psid = Fluid mass density, lbf x s2/in4Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 18 - FIGURE 8 - STANDARD ENVELOPES Copyright SAE International Provided by IHS under
33、license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 19 - FIGURE 9 - STANDARD MOUNTING INTERFACES Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without lice
34、nse from IHS-,-,-SAE ARP490 Revision F - 20 - FIGURE 9 - STANDARD MOUNTING INTERFACES (CONTINUED) Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 21 - 3.2.3.1.1.3 Identificati
35、on (3.1.1.3) An area on each servovalve should be available for the engravement or secure attachment of identifying information. Identification as a minimum should include: a. Manufacturer b. Model Number (Suppliers Model or Part Number) c. Serial Number Additional information may also be included,
36、such as the following: a. Part Number (Customer) b. Rated Pressure c. Rated Current d. Fluid e. Contract number f. Assembly date 3.2.3.1.1.4 Materials (3.1.1.4) Materials used should conform to all applicable specifications and specified environments. Fluid or environmental conditions, etc., often r
37、equire special precautions to be taken regarding the selection of compatible materials to minimize the effects of chemical or electrical reaction, fungus growth, etc. Where applicable, these conditions should be specified. MIL-HDBK-1587 may be used as a guide in the selection of suitable materials.
38、3.2.3.1.1.5 Standard Parts (3.1.1.5) Parts to industry and military standards, such as AS, MA, NAS, MS, or AN, should be used wherever they are suitable for the purpose. 3.2.3.1.1.6 Locking Devices (3.1.1.6) All threaded parts should be securely locked or safetied by safety-wiring, self-locking nuts
39、, or other approved methods. Safety-wire should be applied in accordance with standard NASM33540. Snap rings should not be used as retainers unless they are positively retained in their installed position. 3.2.3.1.1.7 Structural Strength (3.1.1.7) All component parts of the servovalve should have su
40、fficient strength to withstand all loads or combinations of loads resulting from hydraulic pressure, temperature, actuation, and torque loads imposed during installation and operation under rated conditions. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduct
41、ion or networking permitted without license from IHS-,-,-SAE ARP490 Revision F - 22 - 3.2.3.1.1.8 Seals (3.1.1.8) Seals should be of such composition and dimensions so as to satisfy the standardization and operating requirements of the applicable specifications. If a specific seal compound is desire
42、d for certain fluid or environmental conditions, the specification for the compound should be included. In aerospace servovalves it is often necessary to utilize nonstandard seals because of space and weight constraints. Therefore, while the use of standard size seals is desirable, the specification
43、 should permit the use of nonstandard seals when the concurrence of the procuring activity is obtained. Further, to assure adequate seal squeeze under the worst possible combinations of seal size, gland size, seal stretch, and gland eccentricities, the design of any nonstandard seal installations sh
44、ould follow the recommendations put forth in ARP1231. 3.2.3.1.2 Electrical (3.1.2) 3.2.3.1.2.1 Coil Connections (3.1.2.1) The wiring configuration for the torque motor coils should be specified, together with the connector pin identification or lead wire color coding, as applicable. Recommended coil
45、 connections for single-ended, four-wire individual, and four-wire parallel applications are shown in Figure 10. 3.2.3.1.2.2 Rated Current (3.1.2.2) Rated current should be stated in mA for the particular coil connection specified in 3.2.3.1.2.1. Specifying rated current and resistance combinations
46、less than those recommended by the manufacturer may require the servovalve to be designed with less than optimum electrical control power. In general, a very low value for rated current requires the use of extremely small magnet wire, with resultant reliability hazards; so it should be avoided if po
47、ssible. 3.2.3.1.2.3 Quiescent Current If differential coil operation is specified, normal quiescent current values and polarity should be stated. Also, maximum anticipated quiescent current should be specified. If abnormal variations of quiescent current are anticipated, then the range of variation
48、should be stated. 3.2.3.1.2.4 Insulation Resistance (3.1.2.3) The minimum insulation resistance for valve coils and lead wires to the valve body should be specified. The recommended value is 50 M under room temperature and humidity conditions following a 15 s application of a DC potential equal to 500 V, or five times the maximum anticipated coil voltage, whichever is less. 3.2.3.1.2.5 Dielectric Strength (3.1.2.4) For systems where combined environmental effects are of concern, such as
