Multi-channel pump and its control method

Abstract

A multi-channel pump includes a pump chamber, an inflow passage connected to the pump chamber, two or more outflow passages connected to the pump chamber, outflow side active valves provided so as to correspond to the outflow passages, and a movable body reciprocated to change a volumetric capacity of the pump chamber. The movable body may be a piston reciprocated within a cylinder that is connected to the pump chamber. A control method for a multi-channel pump includes an initial discharge step between a suction step and a discharge step.

1 . A multi-channel pump comprising: 
 a pump chamber,    an inflow passage for fluid which is connected to the pump chamber,    two or more outflow passages which are connected to the pump chamber,    outflow side active valves which are provided so as to correspond to the outflow passages; and    a movable body which is reciprocated to change a volumetric capacity of the pump chamber.    
   
   
       2 . The multi-channel pump according to  claim 1 , wherein the movable body is a piston which is reciprocated within a cylinder that is connected to the pump chamber.  
   
   
       3 . The multi-channel pump according to  claim 2 , further comprising: 
 a piston rod to which the piston is fixed;    a male screw formed on an outer peripheral part of the piston rod;    a rotation body which is formed with a female screw that threadedly engages with the male screw to make the piston reciprocate; and    a piston drive motor which drives the rotation body to rotate.    
   
   
       4 . The multi-channel pump according to  claim 3 , wherein the piston drive motor is a stepping motor.  
   
   
       5 . The multi-channel pump according to  claim 1 , wherein the inflow passage comprises two or more inflow passages.  
   
   
       6 . The multi-channel pump according to  claim 1 , further comprising an inflow side active valve through which the inflow passage is connected to the pump chamber.  
   
   
       7 . The multi-channel pump according to  claim 6 , further comprising: 
 a first flow passage provided in the inflow passage and having a passive valve which is capable of opening in an inflow direction to the pump chamber, and    a second flow passage provided in the inflow passage and having a passive valve which is capable of opening in an outflow direction from the pump chamber.    
   
   
       8 . The multi-channel pump according to  claim 1 , further comprising: 
 liquid as the fluid; and    a detector for detecting presence of a bubble in the pump chamber.    
   
   
       9 . The multi-channel pump according to  claim 1 , further comprising: 
 an inflow side active valve through which the inflow passage is connected to the pump chamber,    a drive actuator for inflow side active valve which drives to open and close the inflow side active valve;    a drive actuator for outflow side active valve which individually drives to open and close the outflow side active valves which are provided in the outflow passages; and    a piston as the movable body which is reciprocated within a cylinder that is connected to the pump chamber.    
   
   
       10 . The multi-channel pump according to  claim 9 , further comprising: 
 a first flow passage provided in the inflow passage and having a passive valve which is capable of opening in an inflow direction to the pump chamber, and    a second flow passage provided in the inflow passage and having a passive valve which is capable of opening in an outflow direction from the pump chamber,    wherein the inflow side active valve is provided between the first flow passage, the second flow passage and the pump chamber.    
   
   
       11 . The multi-channel pump according to  claim 9 , further comprising: 
 a valve opening/closing drive motor as the drive actuator for outflow side active valve; and    a cam which is moved by the valve opening/closing drive motor,    wherein the outflow side active valves which are provided so as to correspond to the outflow passages are individually opened and closed by the cam.    
   
   
       12 . A control method for a multi-channel pump comprising: 
 providing a multi-channel pump comprising: 
 a pump chamber,  
 an inflow passage for fluid which is connected to the pump chamber,  
 two or more outflow passages which are connected to the pump chamber,  
 outflow side active valves which are provided so as to correspond to the outflow passages;  
 a movable body which is reciprocated to change a volumetric capacity of the pump chamber, and  
 an inflow side active valve through which the inflow passage is connected to the pump chamber,  
   a suction step in which the inflow side active valve is opened and the fluid is sucked into the pump chamber by a suction operation of the movable body and then the inflow side active valve is closed;    an initial discharge step after the suction step in which one of the outflow side active valves is opened and the fluid is discharged from the pump chamber by the discharge operation of the movable body to eliminate backlash of the pump, and    a discharge step after the initial discharge step in which a prescribed outflow side active valve is successively opened and a prescribed amount of the fluid is discharged by the discharge operation of the movable body.    
   
   
       13 . A control method for a multi-channel pump comprising: 
 providing a multi-channel pump comprising: 
 a pump chamber,  
 an inflow passage for fluid which is connected to the pump chamber,  
 two or more outflow passages which are connected to the pump chamber,  
 outflow side active valves which are provided so as to correspond to the outflow passages;  
 a movable body which is reciprocated to change a volumetric capacity of the pump chamber,  
 a first flow passage provided in the inflow passage and having a passive valve which is capable of opening in an inflow direction to the pump chamber,  
 a second flow passage provided in the inflow passage and having a passive valve which is capable of opening in an outflow direction from the pump chamber, and  
 an inflow side active valve through which the inflow passage is connected to the pump chamber,  
   a suction step in which the inflow side active valve is opened and the fluid is sucked into the pump chamber from the first flow passage by a suction operation of the movable body;    an initial discharge step after the suction step in which the backlash of the pump is eliminated by means of that the fluid is discharged from the pump chamber to the second flow passage by the discharge operation of the movable body and then the inflow side active valve is closed, and    a discharge step after the initial discharge step in which a prescribed outflow side active valve is successively opened and a prescribed amount of the fluid is discharged by the discharge operation of the movable body.