Diaphragm pump

Abstract

The invention discloses a diaphragm pump and belongs to the technical field of pumps. According to the technical scheme, a male part is arranged on a valve plate, and a female part which is in clearance fit with the male part to form a clearance channel is arranged on the air releasing channel. The diaphragm pump disclosed by the invention is capable of reducing the processing difficulty of the air releasing channel and meeting the requirement on extremely small size of air releasing clearance of the air releasing channel.

What is claimed is: 
     
         1 . A diaphragm pump, comprising an upper cover assembly ( 1 ), a piston assembly ( 2 ) and a driving assembly ( 3 ) which are connected in sequence from top to bottom, wherein the upper cover assembly ( 1 ) is provided with an air outlet ( 111 ), a pressure relief opening ( 112 ) and a communicating cavity ( 113 ) which communicates the air outlet ( 111 ) with the pressure relief opening ( 112 ); the diaphragm pump is characterized in that the upper cover assembly ( 1 ) comprises an upper cover body ( 11 ), a valve seat ( 12 ) and a valve plate ( 13 ); the valve plate ( 13 ) is arranged between the valve seat ( 12 ) and the upper cover body ( 11 ); the communicating cavity ( 113 ) is formed when the upper cover body ( 11 ) is covered with the valve seat ( 12 ); a pressure relief airbag ( 134 ) used for opening or closing the pressure relief opening ( 112 ) is arranged on the valve plate ( 13 ); the valve seat ( 12 ) is provided with an air inlet channel ( 1341 ) communicated with the pressure relief airbag ( 134 ) and an air releasing channel ( 1342 ) for releasing air in the pressure relief airbag ( 134 ); the valve plate ( 13 ) is provided with a male part ( 1344 ); and the air releasing channel ( 1342 ) is provided with a female part ( 1343 ) which is in clearance fit with the male part ( 1344 ) to form a clearance channel. 
     
     
         2 . The diaphragm pump according to  claim 1 , characterized in that a flow channel area of the clearance channel between the male part ( 1344 ) and the female part ( 1343 ) is smaller than a cross sectional area of the air inlet channel ( 1341 ). 
     
     
         3 . The diaphragm pump according to  claim 1 , characterized in that the male part ( 1344 ) is an air releasing pillar, and the female part ( 1343 ) is an air releasing groove. 
     
     
         4 . The diaphragm pump according to  claim 1 , characterized in that the male part ( 1344 ) and the valve plate ( 13 ) are integrally formed by injection molding. 
     
     
         5 . The diaphragm pump according to  claim 1 , characterized in that the valve seat ( 12 ) is provided with a positioning pillar ( 6 ) which extends in a direction towards the valve plate ( 13 ) and is arranged in the air releasing airbag ( 134 ). 
     
     
         6 . The diaphragm pump according to  claim 1 , characterized in that positioning protrusions ( 121 ) are arranged on an upper end surface of the valve seat ( 12 ), and positioning holes ( 131 ) for insertion of the positioning protrusions ( 121 ) are formed in the valve plate ( 13 ). 
     
     
         7 . The diaphragm pump according to  claim 6 , characterized in that two positioning protrusions ( 121 ) are arranged; and a connection line between centers of the two positioning protrusions ( 121 ) is an oblique line. 
     
     
         8 . The diaphragm pump according to  claim 1 , characterized in that the piston assembly ( 2 ) comprises a piston seat ( 21 ) arranged at a lower end of the valve seat ( 12 ), a diaphragm part ( 22 ) arranged between the piston seat ( 21 ) and the valve seat ( 12 ) and a substrate ( 23 ) which is arranged at one end away from the valve seat ( 12 ) of the piston seat ( 21 ) and is in transmission connection with the driving assembly ( 3 ); the piston seat ( 21 ) is provided with an air inlet ( 211 ); the diaphragm part ( 22 ) is provided with a one-way inlet ( 221 ) communicated with the air inlet ( 211 ) and piston airbags ( 222 ) which are located at two sides of the one-way inlet ( 221 ) and form a pump chamber; locking holes ( 231 ) are formed in the substrate ( 23 ); and protrusion parts ( 2221 ) clamped in the locking holes ( 231 ) are arranged on the piston airbags ( 222 ). 
     
     
         9 . The diaphragm pump according to  claim 8 , characterized in that positioning blocks ( 212 ) extend in a direction from two sides of an edge of the piston seat ( 21 ) to the valve seat ( 12 ); and the valve seat ( 12 ) is provided with positioning notches ( 213 ) which are embedded with the positioning blocks ( 212 ). 
     
     
         10 . The diaphragm pump according to  claim 9 , characterized in that the driving assembly ( 3 ) comprises a motor ( 32 ), an eccentric wheel ( 33 ) and a connection rod ( 34 ); an output shaft of the motor ( 32 ) is fixed with the eccentric wheel ( 33 ); one end of the connection rod ( 34 ) is eccentrically connected with the eccentric wheel ( 33 ); and the other end of the connection rod ( 34 ) is connected with the substrate ( 23 ).