There are two main limit switches: contact and non-contact.
1, the contact limit switch is relatively intuitive, the stroke switch is installed on the moving parts of the mechanical equipment, and the stop block is installed in the upper limit position or the opposite position, rather than the fixed point of relative motion.
When the mechanical contact of the travel switch contacts the stop block, the control circuit is cut off (or changed), and the machine stops or changes the operation. This type of travel switch has a certain “overtravel” due to mechanical inertia movement to protect the switch from damage.
2, there are many kinds of non-contact limit switches, such as reed tubes and other common elevators.
In the electronic control system, the limit switch also plays the role of checking the sequence control, positioning control and position state. Used to control the stroke and limit protection of mechanical equipment.
Structural features: It consists of an operating head, a contact system and a shell.
3, in the actual production process, the limit switch is installed in a pre-arranged position. When the module installed in the moving parts of the production machinery hits the travel switch, the contact action of the limit switch can realize the circuit conversion.
Therefore, the stroke switch is an electrical appliance that switches the circuit according to the stroke position of the moving parts, and its principle of action is similar to that of a button.
4, limit switch is widely used in a variety of machine tools and lifting machinery, used to control its stroke, protect the terminal limit. In the control circuit of the elevator, the travel switch is also used to control the speed of the door, the limit of the automatic door, and the upper and lower limit of the protection car.
