Diaphragm pump

Abstract

A diaphragm pump includes a diaphragm, a diaphragm case and a driver. The diaphragm has a center point and an outer peripheral portion. The diaphragm case supports the diaphragm at the outer peripheral portion thereof, thereby defining a pump chamber in the diaphragm case. The driver holds the diaphragm at the center point thereof. The diaphragm is deformed as the driver is reciprocated, thereby accomplishing a fluid to flow into and to be discharged out of the pump chamber. The driver includes a fitting member and a flange. The fitting member fits the diaphragm and has a first surface for contacting the diaphragm. The flange is formed outside the fitting member. The flange has a second surface for contacting the diaphragm when the diaphragm is deformed toward the pump chamber. The second surface has a first convex surface region which is formed continuously with the first surface.

1 . A diaphragm pump comprising: 
 a diaphragm having a center point and an outer peripheral portion;    a diaphragm case for supporting the diaphragm at the outer peripheral portion thereof, thereby defining a pump chamber in the diaphragm case;    a driver for holding the diaphragm at the center point thereof, the diaphragm being deformed as the driver is reciprocated, thereby accomplishing a fluid to flow into and to be discharged out of the pump chamber, the driver comprising: 
 a fitting member for fitting the diaphragm, the fitting member having a first surface for contacting the diaphragm; and  
 a flange formed outside the fitting member, the flange having a second surface for contacting the diaphragm when the diaphragm is deformed toward the pump chamber, wherein the second surface of the flange has a first convex surface region which is formed continuously with the first surface of the fitting member.  
   
   
   
       2 . The diaphragm pump according to  claim 1 , wherein the second surface of the flange has a first concave surface region in addition to the first convex surface region, the first convex surface region contacting the diaphragm at a portion of the first convex surface region adjacent to the fitting member, the first concave surface region being formed continuously with the first convex surface region, the first concave surface region contacting the diaphragm at a portion of the first concave surface region adjacent to the outer peripheral portion of the diaphragm.  
   
   
       3 . The diaphragm pump according to  claim 2 , wherein curvatures of the first convex surface region and the first concave surface region of the second surface of the flange are the same.  
   
   
       4 . The diaphragm pump according to  claim 1 , wherein the diaphragm case has a regulating surface which forms an inner surface of the pump chamber and is shaped so as to conform with the second surface of the flange, thereby providing a limit of deformation of the diaphragm toward the pump chamber.  
   
   
       5 . The diaphragm pump according to  claim 4 , wherein the diaphragm case has a fixing surface for supporting the diaphragm at the outer peripheral portion thereof, the regulating surface being formed continuously with the fixing surface, the regulating surface having a second convex surface region for supporting the diaphragm at a portion of the second convex surface region adjacent to the outer peripheral portion of the diaphragm and a second concave surface region which is formed continuously with the second convex surface region for supporting the diaphragm at a portion of the second concave surface region adjacent to the center point of the diaphragm.  
   
   
       6 . The diaphragm pump according to  claim 5 , wherein curvatures of the second convex surface region and the second concave surface region of the regulating surface of the diaphragm case are the same.  
   
   
       7 . The diaphragm pump according to  claim 6 , wherein the second surface of the flange has a first concave surface region in addition to the first convex surface region, the first convex surface region of the second surface contacting the diaphragm at a portion of the first convex surface region adjacent to the fitting member, the first concave surface region of the second surface being formed continuously with the first convex surface region, the first concave surface region contacting the diaphragm at a portion of the first concave surface region adjacent to the outer peripheral portion of the diaphragm, curvatures of the first convex surface region and the first concave surface region of the second surface of the flange and the curvatures of the second convex surface region and the second concave surface region of the regulating surface being the same.