Dewatering machine

Abstract

A dewatering machine including: a dewatering tank, formed in a cylindrical shape with a central axis extending in a direction inclined relative to an up-down direction; a balancing ring coaxially arranged in the dewatering tank, liquid for achieving rotational balance of the dewatering tank is contained in the balancing ring and flows freely; a control part. The control part causes the dewatering tank to rotate at a rotating speed lower than a lowest rotating speed at which the dewatering tank resonates in a dewatering preparation stage of washings, so as to detect a biased position of the washings, causes the dewatering tank to stop rotating immediately before the washings biased in the dewatering tank are positioned at an opposite side of liquid biased downward in the balancing rings to a lower side, relative to the central axis.

1 . A dewatering machine, comprising:
 a dewatering tank, formed in a cylindrical shape with a central axis extending in a direction inclined relative to an up-down direction, wherein the dewatering tank is configured to contain washings, and rotate around the central axis so as to dewater the washings;   a balancing ring, formed in a hollow annular shape, wherein the balancing ring is coaxially arranged in the dewatering tank, and liquid for achieving rotational balance of the dewatering tank is contained in the balancing ring and flows freely; and   a dewatering preparation unit, configured to cause the dewatering tank, in a dewatering preparation stage for the washings, to rotate at a rotating speed lower than a lowest rotating speed at which the dewatering tank resonates, so as to detect a biased position of the washings in the dewatering tank; and cause the dewatering tank to stop rotating immediately before the washings biased in the dewatering tank are positioned, relative to the central axis, at an opposite side of the liquid biased downward in the balancing ring.   
     
     
         2 . A dewatering machine, comprising:
 a dewatering tank, formed in a cylindrical shape with a central axis extending in a direction inclined relative to an up-down direction, wherein the dewatering tank is configured to contain washings, and rotate around the central axis so as to dewater the washings;   an electric motor, configured to cause the dewatering tank to rotate;   an information value acquisition unit, configured to, when the electric motor is in an acceleration state of accelerating to a target rotating speed used for formally dewatering the washings, sequentially acquire an information value that should be decreased as a rotating speed of the electric motor increases;   a counting unit, configured to add a count value with an initial value of zero by 1 once the information value acquisition unit acquires the information value;   a calculation unit, configured to calculate an accumulated value of a difference between the information value and a previous information value under a condition that the information value is larger than the previous information value;   a determination unit, configured to determine that the washings are biased in the dewatering tank under a condition that the accumulated value when the count value is a specified value reaches a first threshold when the count value is the specified value; and   a stopping unit, configured to cause the dewatering tank to stop rotating when it is determined by the determination unit that the washings are biased.   
     
     
         3 . The dewatering machine according to  claim 2 , further comprising an information correction unit, wherein information correction unit is configured to correct the information value through moving average before the accumulated value is calculated by the calculation unit. 
     
     
         4 . The dewatering machine according to  claim 2 , further comprising an execution unit, wherein the execution unit is configured to alternatively execute any of a restarting process and a correction process under a condition that the dewatering tank is stopped rotating through the stopping unit, wherein the restarting process is a process for restarting to dewater the washings by causing the dewatering tank to rotate again, and the correction process is a process for correcting the biasing of the washings in the dewatering tank; and
 the execution unit is configured to select to execute the correction process rather than selecting to execute the restarting process in the following situation: the restarting process has been executed for a specified number, and the dewatering tank is caused to stop rotating by the stopping unit.   
     
     
         5 . The dewatering machine according to  claim 2 , further comprising an acceleration unit, wherein the acceleration unit causes the electric motor to accelerate in three stages including a first acceleration stage, a second acceleration stage and a third acceleration stage, wherein
 the first acceleration stage refers to an acceleration stage, in which the motor accelerates toward the target rotating speed from starting rotating until the rotating speed of the motor reaches a first rotating speed, wherein the first rotating speed is higher than a rotating speed at which the dewatering tank resonates transversely and lower than a rotating speed at which the dewatering tank resonates longitudinally,   the second acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the first rotating speed to a second rotating speed higher than the first rotating speed,   the third acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the second rotating speed to the target rotating speed,   the first threshold is independently set in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, and   the information value acquisition unit is configured to acquire the information value in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, the counting unit causes the count value to be added by 1 and calculates the accumulated value, and the determination unit determines that the washings are biased in the dewatering tank when the accumulated value reaches the first threshold.   
     
     
         6 . The dewatering machine according to  claim 5 , further comprising:
 a duty ratio acquisition unit, configured to acquire a duty ratio of voltage applied to the motor at each specified time in the third acceleration stage; and   a transformation unit, configured to transform the duty ratio acquired by the duty ratio acquisition unit into a specified index value,   when the index value reaches a second threshold for a corresponding time, the determination unit determines that the washings are biased in the dewatering tank.   
     
     
         7 . The dewatering machine according to  claim 6 , further comprising a threshold modification unit, wherein the threshold modification unit is configured to modify the second threshold according to the accumulated value in at least one acceleration stage of the first acceleration stage, the second acceleration stage and the third acceleration stage. 
     
     
         8 . The dewatering machine according to  claim 5 , wherein when a variation of the accumulated value reaches a third threshold, the determination unit determines that the washings are biased in the dewatering tank. 
     
     
         9 . A dewatering machine, comprising:
 a dewatering tank, formed in a cylindrical shape with a central axis extending in a direction inclined relative to an up-down direction, wherein the dewatering tank is configured to contain washings, and rotate around the central axis so as to dewater the washings;   an outer tank, configured to contain the dewatering tank;   an electric motor, configured to cause the dewatering tank to rotate;   a determination unit, configured to determine that the washings are biased in the dewatering tank when an information value, relevant to a rotation state of the electric motor before a rotating speed of the electric motor reaches a target rotating speed used for formally dewatering the washings, reaches a threshold;   a detection unit, configured to mechanically detect eccentric rotation of the dewatering tank by contacting the outer tank when the dewatering tank eccentrically rotates along with biasing of the washings in the dewatering tank and the outer tank is caused to vibrate; and   a stopping unit, configured to cause the dewatering tank to stop rotating in one of the following situations: it is determined by the determination unit that the washings are biased; the eccentric rotation of the dewatering tank is detected by the detection unit.   
     
     
         10 . (canceled) 
     
     
         11 . The dewatering machine according to  claim 3 , further comprising an execution unit, wherein the execution unit is configured to alternatively execute any of a restarting process and a correction process under a condition that the dewatering tank is stopped rotating through the stopping unit, wherein the restarting process is a process for restarting to dewater the washings by causing the dewatering tank to rotate again, and the correction process is a process for correcting the biasing of the washings in the dewatering tank; and
 the execution unit is configured to select to execute the correction process rather than selecting to execute the restarting process in the following situation: the restarting process has been executed for a specified number, and the dewatering tank is caused to stop rotating by the stopping unit.   
     
     
         12 . The dewatering machine according to  claim 3 , further comprising an acceleration unit, wherein the acceleration unit causes the electric motor to accelerate in three stages including a first acceleration stage, a second acceleration stage and a third acceleration stage, wherein
 the first acceleration stage refers to an acceleration stage, in which the motor accelerates toward the target rotating speed from starting rotating until the rotating speed of the motor reaches a first rotating speed, wherein the first rotating speed is higher than a rotating speed at which the dewatering tank resonates transversely and lower than a rotating speed at which the dewatering tank resonates longitudinally,   the second acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the first rotating speed to a second rotating speed higher than the first rotating speed,   the third acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the second rotating speed to the target rotating speed,   the first threshold is independently set in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, and   the information value acquisition unit is configured to acquire the information value in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, the counting unit causes the count value to be added by 1 and calculates the accumulated value, and the determination unit determines that the washings are biased in the dewatering tank when the accumulated value reaches the first threshold.   
     
     
         13 . The dewatering machine according to  claim 4 , further comprising an acceleration unit, wherein the acceleration unit causes the electric motor to accelerate in three stages including a first acceleration stage, a second acceleration stage and a third acceleration stage, wherein
 the first acceleration stage refers to an acceleration stage, in which the motor accelerates toward the target rotating speed from starting rotating until the rotating speed of the motor reaches a first rotating speed, wherein the first rotating speed is higher than a rotating speed at which the dewatering tank resonates transversely and lower than a rotating speed at which the dewatering tank resonates longitudinally,   the second acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the first rotating speed to a second rotating speed higher than the first rotating speed,   the third acceleration stage is an acceleration stage, in which the rotating speed of the motor increases from the second rotating speed to the target rotating speed,   the first threshold is independently set in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, and   the information value acquisition unit is configured to acquire the information value in the first acceleration stage, the second acceleration stage and the third acceleration stage respectively, the counting unit causes the count value to be added by 1 and calculates the accumulated value, and the determination unit determines that the washings are biased in the dewatering tank when the accumulated value reaches the first threshold.   
     
     
         14 . The dewatering machine according to  claim 6 , wherein when a variation of the accumulated value reaches a third threshold, the determination unit determines that the washings are biased in the dewatering tank. 
     
     
         15 . The dewatering machine according to  claim 7 , wherein when a variation of the accumulated value reaches a third threshold, the determination unit determines that the washings are biased in the dewatering tank. 
     
     
         16 . The dewatering machine according to  claim 9 , further comprising a threshold correction unit, configured to correct the threshold in one of the following situations: a difference between the information value and the threshold is above the specified value when the eccentric rotation of the dewatering tank is detected by the detection unit; it is determined by the determination unit that the washings are biased before the eccentric rotation is detected by the detection unit. 
     
     
         17 . The dewatering machine according to  claim 9 , further comprising a suspending unit, configured to suspend an operation performed by the stopping unit for stopping the rotation of the dewatering tank, until a detection number of the detection unit reaches a specified number before it is determined by the determination unit that the washings are biased.