After the train passes, the gap of the switch machine becomes smaller, which leads to internal failure. As an important parameter in the maintenance of the switch machine, the clearance value of the detecting rod of the switch machine will make the switch machine unable to lock due to too large or too small fault, which will lead to the failure of the switch to operate in place, commonly known as "clearance". Turnout is a line connection device that enables locomotives and vehicles to transfer from one track to another, and is usually laid in large quantities in stations and marshalling stations. As an important parameter in the maintenance of the switch machine, the clearance value of the detecting rod of the switch machine will make the switch machine unable to lock due to too large or too small fault, which will lead to the failure of the switch to operate in place, commonly known as "clearance". Turnout is a line connection device that enables locomotives and vehicles to transfer from one track to another, which is widely laid in stations and marshalling stations.