1 Scope
This document specifies the design basis, design guidelines, design process, design methods, test verification and design outputs for electromagnetic relays for astronautics.
This document applies to the design, testing and selection of electromagnetic relays for aerospace applications (hereinafter referred to as relays).
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Among them, note the date of the reference document, only the date of the corresponding version applies to this document; do not note the date of the reference document, its latest version (including all the revision of the list) applies to this document.
GB/T2900.63 - 2003 Electrical terminology basic relay
3 Terms and definitions
The terms defined in GB/T 2900.63--2003 and the following terms and definitions apply to this document.
3.1
Quality function deployment;QFD
A method of quantifying the impact of economic and technical indicators on product quality using a matrix, thereby translating the market demand for product quality into relevant technical and management requirements.
3.2
Design of experiment; DOE
A mathematical and statistical method for arranging tests and analysing test data.
Note. It is a method of organising tests and analysing test data in a mathematical and statistical way, mainly to achieve the desired test results and scientific conclusions with a smaller test size (number of tests), shorter test period and lower test costs.
The test results and scientific conclusions can be obtained with a smaller test size (number of tests), shorter test period and lower test cost.
4 Design basis
The design of a relay is based on: the requirements of the task and contract proposed by the user; the requirements of the self-developed product; and the relevant constraints. These generally include
a) Product use;
b) Basic functional requirements;
c) performance index requirements;
d) Product structure requirements;
e) environmental conditions;
f) Requirements for reliability, serviceability, safety, electromagnetic compatibility and other indicators;
g) Special requirements of the user;
h) Risk assessment requirements;
5 Design guidelines
5.1 Space availability principle
The relays are subject to the following space availability principles:
a) The relay should be suitable for use in a variety of space environments such as high vacuum, high temperature differences, strong radiation, and strong vibration;
b) The non-metallic materials used in the relay should meet the requirements for radiation resistance;
c) The relay shall meet the requirements for cold and hot vacuum immersion, and shall be verified to operate under high vacuum and low temperature conditions. The relay shall meet the requirements for stability in high vacuum and high temperature conditions.
5.2 Principles of advancement and inheritance
The relays shall meet the following requirements for advancement and inheritance:
a) Advanced: The new structure, technology, materials and components used in the design of the relay shall be tested by the relevant accreditation body to prove the validity of the advanced technology while meeting all performance specifications of the relay.
b) Inheritance: The design work is based on mature relays and draws on mature technologies in the industry, including structure, technology, testing, and localisation. The design is based on mature technology and draws on the proven technology of the industry, including structure, technology, inspection and testing techniques, as well as on local structural references and the choice of materials and plating.
5.3 Principles of workmanship and economy
The following principles of workmanship and economy are required for relays:
a) When designing relays and components, it is necessary to take into account the actual level of processing technology, the level of assembly technology and outsourcing production capacity, etc., to optimise and simplify the structure and facilitate processing; to control the accuracy (dimensional tolerance, shape tolerance, position tolerance and surface roughness) to facilitate production assurance; and to consider the combination of plating and plating thickness to facilitate the realisation of product performance;
b) Under the premise of satisfying the requirements of use, choose materials with high cost performance and good processability, giving priority to material categories, grades, varieties and manufacturers with experience in aerospace applications.
5.4 Excess prevention and control principles
The four relays meet the requirements of the principles of excess prevention and control as follows:
a) Preference is given to designs with a high resistance to excess material;
b) Preference is given to materials that produce less unwanted material;
c) Preference should be given to a structural layout that facilitates the removal of contaminants;
d) The whole production process should be targeted to the requirements of the prevention and control of excess materials.
5.5 Prohibited processes and material regulations
Relays are subject to the following process and material prohibitions:
a) The use of non-metallic materials that release harmful gases under vacuum is prohibited;
b) The use of metallic materials such as pure silver, pure tin, etc., which affect reliability, is prohibited;
c) It is prohibited to solder gold-plated wires, leads and terminals without removing the gold from them;
d) The use of silicone or silicone compounds is prohibited;
e) Galvanizing of internal and external parts is prohibited;
f) cadmium plating of internal and external parts is prohibited;
g) The use of mercury or mercury compounds is prohibited;
h) Prohibition of the use of magnesium or magnesium alloys (except for contacts);
6 Design process.
The design of the relay is carried out according to the procedure shown in Figure 1, starting with the identification of requirements in accordance with 7.1 to form a comprehensive design input, followed by the design of the product in accordance with 7.3, followed by the test verification in accordance with Chapter 8 and finally the design output in accordance with Chapter 9. The design output should be checked for conformity with the design input, and if the design input requirements are met, the design process is complete, otherwise the product is re-designed.
7 Design Methodology
7.1 Requirements identification
7.1.1 General rules
Identify requirements through market research and user communication, apply quality function development (QFD), grasp the needs of users, and convert them into quality characteristics to ensure that the users are satisfied.
This is translated into quality characteristics to ensure that the key requirements of the user are fully identified. Requirements are derived from explicit inputs, implicit inputs, environmental and health and safety requirements.
7.1.2 Explicit inputs
Explicit inputs include:
a) Form, installation . Interfaces . Function, performance, specifications, standards and other technical requirements;
7.1.3 Implicit inputs
Implicit inputs include:
a) requirements of relevant standards, including material specifications, process specifications, test specifications, etc;
b) cited generic product specifications or similar generic product specifications that can be drawn upon;
c) environmental performance indicators, electromagnetic compatibility indicators, reliability indicators, safety, serviceability, etc. required for the intended use.
7.1.4 Environment and health and safety
Environmental and health safety includes:
a) The concept of environmental protection shall be established in the design, and the occupational health and safety of the manufacturing and use personnel shall be fully considered. The occupational health and safety of the user;
b) The design shall give priority to materials that meet environmental requirements and suppliers that have passed relevant environmental certification;
c) The design should address the environmental and safety factors and the impact on the occupational health and safety of personnel and formulate measures.
7.2 Design input
The requirements of the user identified by the requirements and the requirements on which the design is based, together form a comprehensive design input that is used as the basis for the development of the project.
7.3 Product design
7.3.1 General rules
The design of the relay shall follow the design input requirements, draw on proven structures and technologies, verify the full performance of the product and assess the technical characteristics of the space environment.
7.3.2 Structural dimensioning
7.3.2.1 General rules
In the design input. The relay structure and dimensions are determined in accordance with the corresponding relay profile, mounting type and dimensions, and lead end type and dimensions.
The design of the relay contact system, then the relay electromagnetic mechanism, and finally the housing and mounting parts are designed according to the relay shape and dimensions determined by the design input.
7.3.2.2 Design of the contact system
7.3.2.2.1 Basic requirements for the design of the contact system
The design of the contact system should take into account the load conditions, environmental requirements. The design of the contact system should take into account load conditions, environmental requirements, external dimensions, the form of the magnetic circuit to be used, the appropriate contact form, contact and reed materials, contact and reed geometry and contact gap, contact pressure, contact overtravel and other parameters; this determines the reaction force characteristics, and then the specific parameters of the magnetic circuit from the reaction force characteristics, safety factor and shock and vibration resistance requirements. The contact system is the key structural unit that should be guaranteed in the design of the relay and the basic requirements are:
a) The contact and reed mass should be light and the reed length should not be too long to ensure that shock and vibration resistance is achieved;
b) Optimisation of the contact gap. Contact pressure and other mechanical parameters, in order to obtain a short contact jump back time.
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Basis of design
5 Design guidelines
6 Design process
7 Design methods
8 Test validation
9 Design output
