1、BRITISH STANDARD BS 4742-4: 1985 ISO 5676:1983 Hydraulic equipment for agricultural machinery Part 4: Specification for hydraulic couplings on braking systems fortrailers and trailed equipment ISO title: Tractors and machinery for agriculture and forestry Hydraulic couplingBraking circuit UDC 631.37
2、2:629.114.2578.4BS4742-4:1985 This British Standard, having been prepared under the directionof the Agricultural Machinery and Implements Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 29 November 1985 BSI 09-1999 The following BSI references relate
3、to the work on this standard: Committee reference AGE/25 Draft for comment 82/83696 DC ISBN 0 580 14692 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Agricultural Machinery and Implements Standards Committee (AGE/-) to Technical Comm
4、ittee AGE/25, upon which the following bodies were represented: Agricultural Engineers Association Association of Hydraulic Equipment Manufacturers British Agricultural and Garden Machinery Association Ltd. Ministry of Agriculture, Fisheries and Food National Farmers Union National Institute of Agri
5、cultural Engineering Amendments issued since publication Amd. No. Date of issue CommentsBS4742-4:1985 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Field of application 1 3 References 1 4 Definitions 1 5 Dimensional characteristics 1 6 Operati
6、ng characteristics and technical specifications 2 7 Fixing of the male half of the coupling 2 FigureDimensions of the hydraulic coupler 1 Publications referred to Inside back coverBS4742-4:1985 ii BSI 09-1999 National foreword This British Standard, which has been prepared under the direction of the
7、Agricultural Machinery and Implements Standards Committee, is identical with ISO 5676:1983 “Tractors and machinery for agriculture and forestry Hydraulic couplingBraking circuit” published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the Inter
8、national Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In Br
9、itish Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The Technical Committee has reviewed the provisions of ISO 2082 and ISO 3104, t
10、o which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. Related British Standards for ISO 2082 and ISO 3104 are, respectively, BS 1706 “Electroplated coatings of cadmium and zinc on iron and steel” and BS 188 “Methods for determinati
11、on of the viscosity of liquids”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-re
12、ferences International Standard Corresponding British Standard ISO 5675:1981 BS 4742 Hydraulic equipment for agricultural machinery Part 2:1983 Specification for hydraulic couplers for general purposes (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi
13、andii, pages1 and 2, an 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.BS4742-4:1985 BSI 09-1999 1 1 Scope This International Standard specifies
14、the conditions for interchangeability, and the operating characteristics and lays down the technical specifications for tests, for the hydraulic couplings on braking systems for towed agriculture and forestry machinery. 2 Field of application This International Standard applies solely to hydraulic b
15、rake couplings. The braking system is of a regulatable type, operated by an increase in pressure within a servicepressure range of between 10 and15MPa(100and150 bar). These devices are used to connect or disconnect the braking circuit each time trailed agricultural or forestry machinery is hitched o
16、r unhitched. 3 References ISO 2082, Metallic coatings Electroplated coatings of cadmium on iron or steel. ISO 3104, Petroleum products Transparent and opaque liquids Determination of kinematic viscosity and calculation of dynamic viscosity. ISO 5675, Agricultural tractors and machinery Hydraulic cou
17、plers for general use Specifications. 4 Definitions See ISO 5675. 5 Dimensional characteristics The coupling shall conform with the figure. NOTEThe sole aim of the configuration of the coupling is to illustrate and give the reference dimensions. It is not intended to convey design requirements. Figu
18、re Dimensions of the hydraulic couplerBS4742-4:1985 2 BSI 09-1999 6 Operating characteristics and technical specifications 6.1 Operating characteristics 6.1.1 Pressures The normal service pressure shall be15MPa(150bar) maximum. When the tractor is operated without a trailer, the unconnected male par
19、t shall be able to withstand the maximum permissible service pressure of15MPa (150 bar). Connection and disconnection of the coupling device should normally only be carried out without pressure in the circuit. Under these conditions, the disconnecting force applied to the locking ring shall be less
20、than 45 N. For connection, a force of less than 150 N shall be applied to the body of the female part. 6.1.2 Temperature The operating temperatures shall be between30 C and 100 C with possible peaks at140 C and shall last not more than 1 h. 6.2 Technical specifications 6.2.1 Seals The seals shall be
21、 compatible with the oils used in agriculture and under the operating conditions specified in 6.1. 6.2.2 Protection The external parts shall be protected by cadmium coating 8 to 12 4m thick or by any other material giving similar protection. 6.2.3 Testing of the male and female parts with hydraulic
22、fluid The following tests shall be carried out using a hydraulic fluid of high fluidity with viscosity of not less than 10 mm 2 /s (10 cSt 1) ) at 54,4 C, not greater than 500 mm 2 /s (500 cSt) at 40 C (see ISO 3104). 6.2.3.1 Hydraulic test pressure Apply a pressure of 22,5 MPa (225 bar) for 5 min:
23、to the male part, to the female part alone, to the connected male and female parts. No leakage, permanent distortion or disconnection shall be observed. 6.2.3.2 Loss of oil and intake of air on coupling Connect the male part and female part to the testing bench by flexible tubing and subject them to
24、 a pressure of 0,01 MPa (0,1 bar). After coupling and uncoupling 100 times in the horizontal position at a temperature of 20 5 C, itshall be verified that: total oil loss has not exceeded 5 ml. 6.2.3.3 Loss of pressure For an output of 20 l/min under a pressure of15MPa (150 bar) at a temperature of
25、20 5 C, the loss of pressure shall not exceed 0,2 MPa (2 bar). 7 Fixing of the male half of the coupling The male part of the coupling shall be mounted on the tractor facing backwards. 1) 1 cSt (centistokes) = 1 mm 2 /sBS4742-4:1985 BSI 09-1999 Publications referred to See national foreword.BS4742-4
26、 1985 ISO 5676:1983 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions
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