Type and main principle of limit switch

Limit switches can be divided into working and upper limits. The working limit switch is mainly used to signal the mechanism action in place. It is to avoid the failure of the mechanism action beyond the design range. Work classes are installed where the mechanism needs to change working conditions. After the switch action, the signal is raised and other relevant actions are performed. The upper limit type is installed at the far end of the mechanism action and is mainly used to protect the mechanism damage caused by excessive movement of the mechanism. Limit switch is an electrical switch mainly used to limit the upper limit position of mechanical equipment. This type of switch has contact type and non-contact type. Contact is more intuitive. The upper limit switch is installed on the moving parts of the mechanical equipment, and the stop block of the upper limit position is installed on the fixed point of relative motion, or the opposite installation position. When the contact of the mechanical equipment contacts the stop block, the control circuit is cut off (or changed), and the mechanical equipment stops or changes its operation.

In actual production, it is installed in a pre-arranged location. When the module impact stroke switch is installed on the moving parts of the production machinery, the contact action can achieve circuit conversion. Therefore, the limit switch is an electrical appliance that converts the circuit according to the stroke position of the moving part, and its principle is similar to that of a button. It is widely used in all kinds of machine tools and lifting machinery, mainly for control stroke and terminal limit protection. In the control circuit of the elevator, it is also used to control the speed of the opening and closing doors, the limit of the automatic opening and closing doors, and the upper and lower limit protection of the carriage.

The principle of the limit switch depends on the collision, connection or disconnection of the control circuit of the mechanical moving parts to achieve a certain practical operation purpose. In general, the switch is mainly used to limit the position or stroke of the mechanical movement, so that the moving mechanical equipment automatically stops, reverse movement, variable speed movement or automatic round-trip movement according to a certain position or stroke.