Gas switching device

A gas switching device, comprising:

• a valve body having an inlet portion and an outlet portion, wherein the inlet portion has an inlet passage for injecting gas;
• the outlet portion has an outlet port and a receiving chamber;
• a wall of the receiving chamber has a side opening communicating with the inlet passage;
• a switching assembly comprising a plug member located in the receiving chamber, wherein the plug member has a through hole located at a radial direction of the plug member and an axial hole communicating with the through hole and the outlet port;
• the plug member is turnable between a first position and a second position in an axial direction of the plug member;
• when the plug member is at the first position, an outer peripheral surface of the plug member closes the side opening;
• when the plug member is at the second position, the through hole communicates with the side opening;
• and
• a manipulating member having a connecting end and has a gas passage therein, wherein an end of the gas passage forms an inlet at the connecting end, and another end of the gas passage is adapted to communicate with a gas pipe;
• the manipulating member is detachably connected to the outlet port via the connecting end;
• the connecting end is connected to the plug member, and the gas passage communicates with the axial hole;
• the manipulating member drives the plug member to turn between the first position and the second position;
• wherein at least one positioning member is disposed on the connecting end of the manipulating member;
• the outlet port of the valve body has a connecting passage;
• an inner wall of the connecting passage has an annular groove;
• an end portion of the outlet port has at least one recess communicating with the annular groove;
• the at least one positioning member enters the annular groove via the at least one recess;
• wherein the outlet portion has a receiving hole;
• the receiving hole has a first section, a second section, and a third section;
• the first section has the connecting passage;
• the second section is located between the first section and the third section;
• a hole wall of the second section is tapered in shape and forms the receiving chamber, and a diameter of the second section gradually decreases in a direction from the first section to the third section;
• a junction between the third section and the second section has a shoulder portion;
• the plug member comprises a tapered section and an extending section;
• an outer peripheral surface of the tapered section matches with the hole wall of the second section;
• the through hole is located on the tapered section;
• the extending section is connected to the tapered section and is located at the third section of the receiving hole;
• the switching assembly comprises an elastic member;
• an end of the elastic member abuts against the shoulder portion, while another end of the elastic member exerts a force on the extending section in a direction way from the shoulder portion, so that the outer peripheral surface of the tapered section abuts against the hole wall of the second section.