Sealed micro switches are widely used in many fields, especially in environments that require a high level of protection. Therefore, manufacturing high-quality sealed micro switches requires excellence in design, material selection, assembly, and testing. This article will introduce the entire design and production process of sealed switches by Unionwell Micro Switch Manufacturer.

Basic Working Principle And Design Of Sealed Micro Switch

Working Principle Of Sealed Micro Switch

A sealed micro switch is an electrical switch that triggers internal contacts through mechanical force. The working principle of a micro switch is to use an operating rod or button to quickly close or open the internal contacts. This rapid switching of contacts can be used to control the opening and closing of circuits, thereby realizing the switch control of various electrical equipment. In a sealed micro switch, the contact system and spring elements are sealed in the housing, and the sealing technology is used to prevent the intrusion of external substances such as water and dust, ensuring its stability and reliability in harsh environments.

Design Features Of Sealing Structure

The design of sealed micro switches involves several important factors, especially waterproof and dustproof. Common sealing levels include IP40 (dustproof) and IP67 (waterproof and dustproof). When designing, it is necessary to consider the selection of sealing rings, shell materials and sealants. The sealing ring is usually made of high temperature and corrosion resistant silicone or rubber materials. The design of the shell must ensure that there are no gaps at each interface, and the shell material needs to have sufficient strength and corrosion resistance.

How To Make The Sealed Switch Waterproof And Dustproof

Ensuring the sealing is the key to the success of the sealed micro switch. The waterproof and dustproof design not only relies on the use of high-quality sealing rings, but also involves reasonable assembly processes. For example, the shell interface of the sealed micro switch should be precisely spliced ​​to avoid any tiny gaps. At the same time, the bottom glue injection process, surface spraying and sealing treatment of the wire terminals are all important measures to improve the waterproof and dustproof performance.

Determining Sealed Basic Switch Requirements

Model Selection

Different applications have different requirements for sealed micro switches. For example, micro switches in the automotive field need to have strong shock resistance and high waterproof and dustproof capabilities, such as Unionwell's G3 series subminiature sealed micro switches; while micro switches in household appliances consider operation accuracy and long life more, such as Unionwell G5W11 series miniature basic micro switch. When choosing a model, you need to choose a suitable switch model based on the special requirements of the usage scenario, such as temperature range, load capacity, environmental factors, etc.

Determine The Parameters

Determining the parameters of the sealed micro switch is a key step in the design process. Common parameters include operating voltage, current carrying capacity, mechanical life and electrical life. The operating voltage and current need to match the characteristics of the load in the actual application to ensure that the switch can work properly. The mechanical life and electrical life are closely related to the frequency of use of the switch and the environmental conditions.

Design Drawings

Design drawings are the basis for the production of sealed micro switches. Designers need to draw detailed electrical schematics and mechanical structure drawings to ensure that the size and assembly position of each component meet the requirements. The electrical schematics need to clearly indicate the electrical connection method, the movement trajectory of the contacts, and the closed or open state of the contacts. The mechanical structure drawings need to indicate the detailed dimensions of the switch housing, sealing ring, terminal blocks and other components.

Circuit Design

Design Circuit Form (NO, NC)

Depending on the application requirements, the choice of circuit form is crucial. Normally open (NO) circuits remain open when no external force is applied, and the circuit is closed only when triggered. Normally closed (NC) circuits are the opposite, the circuit remains closed before triggering, and the circuit is open after triggering. Choosing the appropriate circuit form according to the use environment and requirements can ensure the stable and reliable function of the switch.

Functional Modules

In addition to the basic switch functions, some additional functional modules can be designed during circuit design. For example, current overload protection circuit, electromagnetic interference suppression circuit, etc., to enhance the safety and stability of the switch. For micro switches in the automotive field, the design of anti-vibration modules also needs to be considered to ensure that the switch does not fail during long-term use in complex automotive environments.

Micro Switch Assembly

Housing Assembly

The assembly of the housing is the basis for ensuring the structural stability of the sealed microswitch. The housing is generally made of materials such as engineering plastics, metal alloys or stainless steel to provide solid protection. The housing must be assembled accurately to ensure that all interfaces are well sealed. It is common to use injection molding to manufacture the housing, which can ensure that the housing has a precise shape and sufficient strength.

Terminal Assembly

Terminals are key components of electrical connections and must ensure reliable contact. Common terminal materials are copper or copper alloys, and the surface can be silver-plated or gold-plated to improve corrosion resistance and conductivity. The assembly of the terminals needs to ensure that the connection with the cable is firm and will not loosen to avoid electrical failures caused by poor contact.

Operating Handle Assembly

The operating handle is the main part of the user's interaction with the micro switch. It must be designed to be easy to operate and able to withstand the pressure caused by long-term use. The operating handle can have different shapes and materials, and the common ones are plastic, metal, and silicone. Depending on the use occasion, the design of the operating handle should adapt to different mechanical requirements.

Sealing Processing

Add A Sealing Ring On The Top

A sealing ring is usually added to the top of the sealed micro switch to ensure that water and dust cannot enter. The material of the sealing ring is generally made of highly elastic silicone or rubber. These materials are not only resistant to high temperatures, but also have good elasticity and can maintain the sealing effect after long-term use. When designing, it is necessary to ensure close contact between the sealing ring and the housing.

Bottom Glue Injection Sealing

Bottom glue injection is another key process to improve sealing performance. By injecting special sealant (such as epoxy resin or polyurethane glue) at the bottom, the tiny gap between the shell and the bottom can be filled to enhance the waterproof and dustproof capabilities. The glue injection process can not only improve the sealing of the switch, but also prevent sealing failure caused by mechanical vibration or impact.

Performance Testing

Sealing Test Method

The sealing of a sealed micro switch is one of the key performances. Common sealing test methods include immersion test, air pressure test and salt spray test. The immersion test checks whether the waterproof performance of the switch meets the standard by immersing the switch in water of a certain depth; the air pressure test simulates a high-pressure environment to test the sealing of the switch under high pressure; the salt spray test is used to evaluate the corrosion resistance of the switch in a salt spray environment.

Durability And Reliability Testing

The durability test of sealed micro switches usually includes mechanical life test, electrical life test and environmental adaptability test. The mechanical life test simulates the operating frequency of the switch to evaluate its mechanical stability under long-term use; the electrical life test evaluates the electrical stability of the switch by repeatedly switching the current on and off; the environmental adaptability test verifies the reliability of the switch in high temperature, low temperature, high humidity, vibration and other environments.

Sample Delivery

During the production process, manufacturers need to send samples to customers for actual testing and verification. The provision of samples should include detailed technical documentation and test reports to help customers better understand the performance and applicability of the product. Through sample verification, customers can evaluate the quality of the switch in advance to ensure that it meets the project requirements.

Automated Mass Production

Once the sample has been verified by the customer and confirmed to meet the requirements, it can enter the automated mass production stage. Through the automated production line, production efficiency and product consistency can be improved to ensure that the quality of each sealed micro switch meets the standards. Automated production can also reduce the error rate of manual operation and reduce production costs.

Packaging And Shipping

Finally, the sealed micro switch will be packaged after strict quality inspection. The packaging material should have good shockproof and waterproof properties to ensure that it is not damaged during transportation. After packaging, the switch will be shipped according to customer requirements to ensure that it reaches the customer on time.

Conclusion

Manufacturing high-quality sealed micro switches requires a series of precise design, material selection, assembly and testing processes. From the drawing of design drawings to the delivery of the final product, each step needs to be precisely controlled to ensure that the switch has excellent electrical performance and excellent sealing performance. With the continuous development of technology, sealed micro switches will play an important role in more fields.