Anti-theft well cover lock and its unlocking spanner

The utility model relates to an anti-theft well cover lock and an unlocking spanner thereof. The anti-theft well cover lock comprises a lock rod and a lock tongue. The upper end of the lock rod is a cylindrical lock rod head. The lock tongue and the lock rod are fastened together. The utility model is characterized in that the cylindrical lock rod head is provided with a conical hole, and the opening of the conical hole is small, and the hole of the conical hole is large. A compression spring can be sheathed on the lock rod. A positioning pin is fastened by the lock tongue. When the anti-theft well cover lock is used, the lock rod is installed at a lock seat of a well cover plate. The unlocking spanner comprises a spanner rod and an unlocking head. The utility model is characterized in that the spanner rod and the unlocking head are two-body structures. The spanner rod is provided with a handle and a conical table. The middle part of the spanner rod is provided with an outer thread. An expansion cylinder is screwed on the spanner rod. The unlocking head is an expanding lock head, and is arranged on one end of the expansion cylinder. An inner thread and an inner light hole are arranged in the expansion cylinder. The expansion unlocking head and the inner light hole are provided with a plurality of longitudinal grooves. The outer diameter of the expansion unlocking head is matched with a hole opening of the conical hole of the anti-theft well cover lock. The expansion unlocking head is provided with a conical hole. The inner conical surface of the conical hole is matched with the outer conical surface of the conical table of the spanner rod. The anti-theft well cover lock and the unlocking spanner thereof have simple structure, firmness, reliability and good anti-theft performance.