Diaphragm Pump

Abstract

Provided is a diaphragm pump including: a pump part that pumps a target liquid, and a drive part that drives the pump part. The pump part includes a pumping chamber, a working chamber, an intermediate chamber that is located between the pumping chamber and the working chamber, a liquid contact diaphragm that closes between the pumping chamber and the intermediate chamber, a working diaphragm that closes between the intermediate chamber and the working chamber, and a working mechanism that causes the liquid contact diaphragm and the working diaphragm to reciprocate so as to change the volume of each of the chambers. The working mechanism includes a working part that reciprocates by the driving of the drive part, a coupling part that couples the liquid contact diaphragm and the working diaphragm, and a biasing part that biases the working diaphragm toward a suction side.

What is claimed is: 
     
         1 . A diaphragm pump including:
 a pump part that pumps a target liquid by suctioning and ejecting, and a drive part that drives the pump part to pump the target liquid,   the pump part including:   a pumping part that includes a suction part that suctions the target liquid,   and an ejection part that ejects the suctioned target liquid,   a working chamber that is filled with hydraulic liquid,   an intermediate chamber that is located between the pumping chamber and the working chamber, and that is filled with intermediate liquid,   a liquid contact diaphragm that is configured to close between the pumping chamber and the intermediate chamber,   a working diaphragm that is configured to close between the intermediate chamber and the working chamber, and   a working mechanism that is configured to cause the liquid contact diaphragm and the working diaphragm to deform in one direction when the target liquid is suctioned, and to deform in an other direction opposite to the one direction when the target liquid is ejected, so as to change the volume of each of the pumping chamber, the working chamber, and the intermediate chamber,   the working mechanism including a working part that is connected to the working diaphragm and configured to reciprocates in the one direction and the other direction by the driving of the drive part, a coupling part that couples the liquid contact diaphragm and the working diaphragm, and a biasing part that biases at least one of the liquid contact diaphragm and the working diaphragm toward the one direction side.   
     
     
         2 . The diaphragm pump according to  claim 1 , in which the coupling part is located in the intermediate chamber and is configured to couple center portions of the liquid contact diaphragm and the working diaphragm. 
     
     
         3 . The diaphragm pump according to  claim 1 or 2 , wherein
 the biasing part is configured to bias at least one of the liquid contact diaphragm and the working diaphragm so as to make the pressure of the pumping chamber smaller than the pressure of the intermediate chamber and the pressure of the working chamber, and make the pressure of the intermediate chamber smaller than the pressure of the working chamber.   
     
     
         4 . The diaphragm pump according to  claim 1 , further comprising a breakage detection device configured to detect breakage of at least one of the liquid contact diaphragm and the working diaphragm based on at least the pressure of the intermediate chamber out of the pressure of the pumping chamber, the pressure of the intermediate chamber, and the pressure of the working chamber. 
     
     
         5 . The diaphragm pump according to  claim 4 , wherein the breakage detection device is configured to detect breakage of the working diaphragm based on the pressure relationship between the pressure of the intermediate chamber and the pressure of the pumping chamber or the pressure of the working chamber. 
     
     
         6 . The diaphragm pump according to  claim 4 or 5 , wherein the breakage detection device is configured to detect breakage of the liquid contact diaphragm based on the pressure relationship between the pressure of the intermediate chamber and the pressure of the pumping chamber or the pressure of the working chamber.