However, after the key is extended into the key hole of the lock core, the slot on the key compresses the bullets in the lock core bullet downward, which just overwhelms the bullets in the hole of the lock core bullet, and flattens the other side of the hole of the lock core bullet (the contact surface between the hole of the lock core bullet and the hole of the lock body bullet). At this time, all the bullets in the hole of the lock body bullet are pressed downward by the bullets in the hole of the lock core bullet. The function is also all flattened by the lock body bullet hole, back to the lock body bullet hole. At this time, the bullet in the hole of the lock body bullet can not be jammed into the hole of the lock core bullet, and the bullet pressed down in the hole of the lock body bullet can not be pressed into the hole of the lock body bullet, that is to say, there is nothing to jam the circular core. Then the key can be used to rotate the lock core. After the lock core rotates, the internal mechanism of the lock body is driven and the lock is opened. This is the principle of unlocking. Therefore, as long as it is a circular lock, the principle of unlocking is exactly the same.
The lock is opened with a key. Why can the same key open the same lock? In the previous section, the state of unlocking is described, that is, when the key presses all the bullets in the bullet hole of the lock body back to the contact surface between the lock core and the bullet hole of the lock body, the lock can be opened by twisting the lock core. This determines that the key must be able to lock all the bullets in the hole of the lock body back to the contact surface (lock body and lock heart) in order to play the unlocking function. Because of the lock manufactured by the manufacturer, the bullets in the bullet holes of the lock body are of the same size and length, while the bullets in the bullet holes of the lock core are of the same size but not necessarily of the same length. This determines that the concave groove of the corresponding key has a deep and shallow difference. For example, according to a five-tooth key, the lock head corresponding to the key must have five bullet holes on the lock core and the lock body (except for the card holes). When the bullet holes of the lock body coincide with the bullet holes of the lock core to form five bullet holes, each bullet hole has a spring and two bullets. Usually people look in from the keyhole, and the row of marbles that can be seen with the eyes is called the front marbles. The second bullet is pressed into the hole below by the front bullet. Each marble has its own purpose. The different lengths of the front marbles in the hole of the lock core determine the different keys, which also determines the truth that the same key opens the same lock. After inserting the key into the keyhole, each groove in the key is aimed at each marble. If the front marble is long, the corresponding groove depth on the key will be deep; on the contrary, the groove depth on the key will be shallow. You might as well open a lock to observe and analyze. The front marble and the second marble are closely related and mutually restricted. The length of the front marble determines the depth at which the second marble can be pushed into the hole of the lock core by a spring. That is to say, if the front bullet is long, it will occupy more positions in the hole of the lock core bullet. In this way, there is less space left in the hole of the core-lock bullet, and the depth of the second bullet entering the hole of the core-lock bullet is shallow. On the contrary, if the front marble is short, the concentration of the second marble into the hole of the lock core marble will be deep.
That is the same key has the same lock to open the truth.