The stroke switch is also known as the position switch or limit switch a, its role is the same as the button, but the action of the stroke switch contact is not manually operated, but the use of the stopper on some moving parts of the production machinery to collide with its roller so that the contact action can be switched on or off some circuits, which is used to control the direction of movement of the production machinery, the size of the stroke or the position protection. The button requires us to manually operate in order to make it move the contact action.

Working principle of travel switch

Commonly used stroke switches are bump block type (linear type) and roller type. Roller type is divided into automatic recovery type and non-automatic recovery type. Non-automatic recovery requires bumping the moving parts when they run in reverse to reset them.

The working principle of ram type and roller type travel switch 9 is basically the same, taking ram type travel switch 9 as an example to explain its working principle. Figure 1 is the structure diagram of the ram type travel switch, and Figure 2 is the symbol of the normally open contact of the travel switch. When the ejector rod is in normal state (not under pressure), the normally closed contact is closed (the moving contact contacts with the above pair of static contacts), and the normally open contact 9 is disconnected (the moving contact does not contact with the following pair of static contacts); When the top dry is under pressure, the moving contact moves down, the normally closed contact is disconnected first, and the normally open contact is closed later. When the top feeling is released (the pressure disappears), the moving contact moves up, the normally open contact is disconnected first, and the normally closed contact is closed later!

Selection of travel switch

(1) According to the application and control object, choose whether it is general use or lifting equipment-9 stroke switch;

(2) Select which series of travel switches according to the installation environment;

(3) According to the transmission form of the mechanical and travel switch, it is open or protected;

(4) Select the appropriate head structure according to the current and voltage, power and displacement relationship of the control loop.