The travel switch, also known as the limit switch, is used to control the travel and limit protection of mechanical equipment. In actual production, the travel switch is installed in a pre-arranged position. When the module installed on the moving parts of the production machinery hits the travel switch, the contacts of the travel switch act to realize the switching of the circuit. Therefore, the travel switch is an electrical appliance that switches the circuit according to the travel position of the moving part, and its working principle is similar to that of a button. Travel switches are widely used in various machine tools and hoisting machinery to control their travel and perform terminal limit protection. In the control circuit of the elevator, the travel switch is also used to control the speed of opening and closing the car door, the limit of the automatic door opening and closing, and the upper and lower limit protection of the car.
The travel switch must have two sets of contacts, normally open and normally closed. The travel switch is used in the forward and reverse circuit. The travel switch is normally open and closed and the reverse is started. The same reverse is also serially closed. Stop, normally open and close, the motor runs forward.
In the travel control of the electromechanical equipment, its action does not require human operation. The main purpose is to use the collision or induction of some moving parts of the production machinery to make its contacts move, and issue control commands to achieve near and far. Distance travel control and limit protection. The main structure of the travel switch is generally composed of three parts: the operating mechanism, the contact system and the shell: according to its structure, it can be divided into direct-acting type, roller type and micro-moving type; according to its reset method, it can be divided into automatic and non-automatic reset; Its contact properties can be divided into contact type and non-contact type. In order to be suitable for different working environments, the travel switch can be made into a variety of structural shapes
