Travel switch is also known as the limit switch, there are often open and often closed points, usually used in the elevator above the more widely, is a commonly used small current main command appliance, is a position switch, composed of the operating head, contact system and shell. The structure inside the stroke switch is the same as the ordinary manual button and the foot button, but the outside operating mechanism is not the same in the form of a rotary, a push type, when the motion mechanism is in place, touch the operating mechanism of the stroke switch, drive the internal switch contact open and close. It can be mounted on relatively stationary objects (such as fixed frames, door frames, etc., referred to as still life) or moving objects (such as cars, doors, etc., referred to as animals). When the animal approaches the still life, the link of the switch drives the contact of the switch causing the closed contact to break or the open contact to close. The action of the circuit and mechanism is controlled by the change of the opening and closing states of the switch contact. Travel switch is widely used in all kinds of machine tools and lifting machinery to control their travel, terminal limit protection. In the control circuit of the elevator, the travel switch is also used to control the speed of the opening and closing of the car door, the limit of the automatic opening and closing, the upper and lower protection of the car.
Travel switch, also known as limit switch, is used to control the travel of mechanical equipment and limit protection. In the actual production, the travel switch is installed in the pre-arranged position. When the module installed on the moving parts of the production machinery hits the travel switch, the contact action of the travel switch is realized to switch the circuit. Therefore, a trip switch is an appliance that switches circuits according to the trip position of a moving part, and it acts on a similar principle as a button.
Travel switch type characteristics
1. Conventional domestic trip switch
Lx19-001/111 in LX19 series, LXK3-20S/T in LXK3 series, JLXK1 series JLXK1-111/411/511 are the most representative. These products have the advantages of simple structure, practical function and low price and are favored by the majority of users.
2. Import trip switch
Import trip switch WL series, HL series, D4V series, SSL-WL series is the most representative force, such products fine workmanship, superior performance, in the extreme environment performance is more prominent, won a large number of fans, but the high price also makes many users shocked
3. High temperature resistant travel switch
The most influential of the domestic high temperature resistant stroke switches is YNTH series high temperature resistant stroke switches, which are generally used in steel mills. YNTH stroke switch can work normally in high temperature environment, the highest working temperature is 350 degrees. The service life of the product will decrease when the working temperature increases. The workload of the switch should be reduced when the temperature exceeds 300 degrees to ensure the service life of the product. This series of travel switch low price, stable performance has won the majority of customers praise.
4, waterproof travel switch
YNFS (TZ) series is more prominent in domestic waterproof stroke switch. YNFS travel switch has the characteristics of small volume, high sensitivity, strong sealing, oil resistance and corrosion resistance. The most amazing thing is that this kind of travel switch can be put in water to make similar products.
Travel switch classification
According to its structure, the stroke switch can be divided into direct motion type, roller type, micro motion type.
1. Direct motion stroke switch
The action principle is similar to that of a button, except that one is manual and the other is collided by a bump block of the moving part. When the collision block on the external moving parts hits the button to make its contact action, when the moving parts leave, under the action of the spring, its contact automatically reset. Its structure principle is shown in Figure F1, and its action principle is the same as that of the button switch. However, the opening and closing speed of the contact depends on the running speed of the production machinery, so it is not suitable for places where the speed is lower than 0.4m/min. When the running speed is lower than 0.4m/min, the contact breaking speed will be very slow, and the contact is susceptible to arc burning.
2. Roller type travel switch
When the collision block on the controlled machinery hits the collision rod with a roller, the collision rod turns to the right, driving the CAM rotation, top and down the push rod, so that the contact in the micro switch acts quickly. When the moving machinery returns, under the action of the reset spring, each part of the action parts reset.
3. Roller type travel switch
Roller type travel switch is divided into single roller automatic reset and double roller (Angle type) non-automatic reset type, double roller row shift switch has two steady position, there is a "memory" function, in some cases can simplify the line.
4, micro switch stroke switch
The micro-moving stroke switch is composed of push rod, spring, compression spring, moving breaking contact and moving closing contact. Author: Longfeng Electric Automation
