An inshot pressure limiting mechanism , comprising: a valve body , an inshot valve , an inflation valve , and a pressure limiting member , wherein the valve body is provided with an air inlet , a first chamber , a second chamber , and an air outlet , and both the first chamber and the second chamber are in communication with the air inlet , and the first chamber is in communication with the second chamber ; the inshot valve is provided in the first chamber ; the inflation valve is provided in the second chamber ; the pressure limiting member is provided in the valve body , and a pressure limiting chamber is formed between the pressure limiting member and the valve body , the pressure limiting chamber is in communication with the air outlet , and both the pressure limiting chamber and the air outlet are in communication with the second chamber ; and the inshot valve and the inflation valve are both connected to the pressure limiting member , and the pressure limiting member is configured to drive the inshot valve and the inflation valve to move during pressure change in the pressure limiting chamber , so that the first chamber and the second chamber are simultaneously in an open state; or the first chamber is in a closed state, and the second chamber is in an open state; or the first chamber and the second chamber are simultaneously in a closed state; characterized in that : the inshot pressure limiting mechanism further comprises a contraction plug ; and the valve body is further provided with a first passage and a second passage ; the first passage makes the air inlet communicate with the first chamber , the second passage makes the air inlet communicate with the second chamber ; and the contraction plug is provided in the second passage . a valve body , an inshot valve , an inflation valve , and a pressure limiting member , wherein the valve body is provided with an air inlet , a first chamber , a second chamber , and an air outlet , and both the first chamber and the second chamber are in communication with the air inlet , and the first chamber is in communication with the second chamber ; the inshot valve is provided in the first chamber ; the inflation valve is provided in the second chamber ; the pressure limiting member is provided in the valve body , and a pressure limiting chamber is formed between the pressure limiting member and the valve body , the pressure limiting chamber is in communication with the air outlet , and both the pressure limiting chamber and the air outlet are in communication with the second chamber ; and the inshot valve and the inflation valve are both connected to the pressure limiting member , and the pressure limiting member is configured to drive the inshot valve and the inflation valve to move during pressure change in the pressure limiting chamber , so that the first chamber and the second chamber are simultaneously in an open state; or the first chamber is in a closed state, and the second chamber is in an open state; or the first chamber and the second chamber are simultaneously in a closed state; characterized in that : the inshot pressure limiting mechanism further comprises a contraction plug ; and the valve body is further provided with a first passage and a second passage ; the first passage makes the air inlet communicate with the first chamber , the second passage makes the air inlet communicate with the second chamber ; and the contraction plug is provided in the second passage . the inshot pressure limiting mechanism further comprises a contraction plug ; and the valve body is further provided with a first passage and a second passage ; the first passage makes the air inlet communicate with the first chamber , the second passage makes the air inlet communicate with the second chamber ; and the contraction plug is provided in the second passage . <EOS>