Limit switches, also known as travel switches, can be mounted on relatively stationary objects (such as fixed Frames, door frames, etc., referred to as "still life" or moving objects (such as driving, doors, etc., referred to as animals). When the animal approaches the still life, the contact of the switch's linkage drive switch causes the closed contact to break or the open contact to close. The circuit and the motor are controlled by the change of the switch contact opening and closing state.
The limit switch is an electrical switch used to define the limit position of the motion of the mechanical device. Limit switches are available in contact and non-contact. The contact type is relatively intuitive. On the moving parts of the mechanical equipment, the upper stroke switch is installed, and the stop position of the limit position is fixed at a fixed point relative to the movement, or the opposite installation position. When the mechanical contact of the travel switch hits the stop, the control circuit is cut (or changed) and the machine stops or changes operation. Due to the inertial motion of the machine, this limit switch has a certain "overtravel" to protect the switch from damage. There are many non-contact forms, such as reed switches, photoelectric, inductive, etc. These forms can be seen in elevators. Of course there are more advanced forms.
The limit switch is a commonly used small current main electric appliance. The collision or control circuit is realized by the collision of the moving parts of the production machinery to make the contact action to achieve a certain control purpose. Typically, such switches are used to limit the position or travel of the mechanical motion, allowing the motion machine to automatically stop, reverse, shift, or automatically reciprocate at a certain position or stroke.
In the electrical control system, the role of the limit switch is to achieve sequential control, positioning control and position status detection. Used to control the travel and limit protection of mechanical equipment. Construction: consists of the operating head, the contact system and the housing.
In actual production, the limit switch is installed in a pre-arranged position. When the module mounted on the moving part of the production machine hits the travel switch, the contact of the limit switch acts to realize the switching of the circuit. Therefore, the stroke switch is an electric appliance that switches the circuit according to the stroke position of the moving part, and its function is similar to that of the button.
Limit switches are widely used in various types of machine tools and lifting machinery to control their travel and limit the terminal. In the control circuit of the elevator, the travel switch is also used to control the speed of the switch car door, the limit of the automatic door opening and closing, and the upper and lower limit protection of the car.
