Liquid transport device and liquid transport method

Abstract

A liquid transport device includes an elastic tube, fingers that line up along a transport direction, a drive mechanism that drives the fingers, a temperature sensor that measures the ambient temperature of the tube, and a control unit. The control unit controls the drive mechanism such that the finger on the most upstream side of the transport direction starts a closing operation of squeezing the tube after the finger on the most downstream side of the transport direction completes the closing operation of squeezing the tube, and the finger second from the downstream side completes an opening operation of being pressed back by the tube. The control unit controls the rate of driving of the drive mechanism in a corrective manner based on a result of measurement by the temperature sensor. The liquid transport device can transport a liquid with high accuracy regardless of the ambient temperature of the tube.

What is claimed is: 
     
         1 . A liquid transport device comprising:
 a tube that has elasticity and is intended to transport a liquid in a transport direction;   a plurality of fingers that is lined up along the transport direction;   a drive mechanism that drives the plurality of fingers;   a temperature sensor that measures the ambient temperature of the tube; and   a control unit that controls the drive mechanism in a manner in which a liquid inside the tube is transported in the transport direction by repeating a closing operation of squeezing the tube with the finger and an opening operation in which the finger is pressed back by the shape of the squeezed tube being restored,   wherein the control unit   controls the drive mechanism in a manner in which the finger on the most upstream side of the transport direction starts the closing operation after the finger on the most downstream side of the transport direction completes the closing operation, and the finger that is second from the downstream side of the transport direction completes the opening operation, and   controls the rate of driving of the drive mechanism in a corrective manner on the basis of a result of measurement by the temperature sensor.   
     
     
         2 . The liquid transport device according to  claim 1 ,
 wherein the rate of driving of the drive mechanism is the amount of rotation of the drive mechanism.   
     
     
         3 . The liquid transport device according to  claim 1 ,
 wherein the drive mechanism includes a piezoelectric motor, and   the temperature sensor is a sensor that measures the ambient temperature of the piezoelectric motor for use in control of drive of the piezoelectric motor.   
     
     
         4 . The liquid transport device according to  claim 1 ,
 wherein the control unit controls the drive mechanism in a manner in which the speed of drive of the drive mechanism is constant.   
     
     
         5 . The liquid transport device according to  claim 1 ,
 wherein the control unit changes the speed of the drive mechanism to an extent in which the finger on the most upstream side starts the closing operation after the finger on the most downstream side completes the closing operation, and the finger that is second from the downstream side completes the opening operation.   
     
     
         6 . The liquid transport device according to  claim 1 ,
 wherein the extent of the cross section of the inside of the tube after the opening operation is completed, the cross section being taken by cutting the tube in a direction that is perpendicular to the axial direction of the tube, changes depending on the ambient temperature of the tube.   
     
     
         7 . The liquid transport device according to  claim 1 ,
 wherein the control unit controls the drive mechanism in a manner in which a transport operation of transporting a liquid in the tube with drive of the plurality of fingers and a stopping operation of not transporting a liquid in the tube with stopping of drive of the plurality of fingers are alternately repeated.   
     
     
         8 . A liquid transport method for a liquid transport device that includes a tube which has elasticity and is intended to transport a liquid in a transport direction, a plurality of fingers which is lined up along the transport direction, and a drive mechanism which drives the plurality of fingers, in which a liquid in the tube is transported in the transport direction by repeating a closing operation of squeezing the tube with the finger and an opening operation in which the finger is pressed back by the shape of the squeezed tube being restored, the method comprising:
 obtaining the ambient temperature of the tube; and   driving the plurality of fingers with the drive mechanism at a rate of driving that is corrected on the basis of the ambient temperature and driving the plurality of fingers in a manner in which the finger on the most upstream side of the transport direction starts the closing operation after the finger on the most downstream side of the transport direction completes the closing operation, and the finger that is second from the downstream side of the transport direction completes the opening operation.