Temperature-sensing piezoelectric dispenser
Provided is a temperature-sensing piezoelectric dispenser, and more particularly, to a dispenser including a piezoelectric pump dispensing a liquid by using a piezoelectric element as an actuator. According to the temperature-sensing piezoelectric dispenser, a temperature of a piezoelectric actuator is measured and the piezoelectric actuator is cooled based on the measured temperature, thereby accurately controlling a liquid discharged according to an operation of the piezoelectric actuator.
1. A temperature-sensing piezoelectric dispenser comprising:
a pump body comprising a cooling line, through which a cooling fluid flows;
a lever that is rotatably installed with respect to a hinge axis installed in the pump body;
a first and second piezoelectric actuator installed in the pump body and each having a tip portion that is contactable to the lever as a length of the first or second piezoelectric actuator is increased when a voltage is applied to the first or second piezoelectric actuator to press and rotate the lever with respect to the hinge axis;
a valve rod that is liftably connected to the lever according to rotation of the lever;
a valve body comprising a storing unit, into which a tip portion of the valve rod is inserted and in which a liquid is stored, an inlet, through which the liquid flows into the storing unit, and a nozzle, through which the liquid of the storing unit is discharged according to advance and retreat of the valve rod with respect to the storing unit;
a temperature sensor installed in one of the first or second piezoelectric actuator and the pump body to measure a temperature;
a cooling pump for supplying the cooling fluid to the cooling line of the pump body; and
a control unit for operating the first and second piezoelectric actuator and receiving the temperature sensed by using the temperature sensor to operate the cooling pump,
wherein the first piezoelectric actuator and the second piezoelectric actuator rotate the lever with respect to the hinge axis in opposite directions from each other when a voltage is applied to the first piezoelectric actuator or the second piezoelectric actuator by the control unit.
2. The temperature-sensing piezoelectric dispenser of claim 1 , wherein the control unit adjusts a flow of the cooling pump so that the temperature sensed by using the temperature sensor is maintained within a preset temperature range.
3. The temperature-sensing piezoelectric dispenser of claim 2 , wherein the cooling fluid is one of air, water, and cooling oil.
4. The temperature-sensing piezoelectric dispenser of claim 1 , wherein the control unit adjusts at least one of a voltage and a frequency of a current applied to the first or second piezoelectric actuator by considering an actuation displacement of the first or second piezoelectric actuator that is varied according to the temperature sensed by using the temperature sensor.
5. The temperature-sensing piezoelectric dispenser of claim 1 , wherein the first piezoelectric actuator and the second piezoelectric actuator are disposed in parallel to each other, with the hinge axis of the pump body included therebetween.
6. The temperature-sensing piezoelectric dispenser of claim 1 , wherein the first piezoelectric actuator and the second piezoelectric actuator are disposed to face each other, with the lever included therebetween.
7. The temperature-sensing piezoelectric dispenser of claim 1 , further comprising:
a first returning unit for applying a force to the first piezoelectric actuator in a direction in which the first piezoelectric actuator is contracted; and
a second returning unit for applying a force to the second piezoelectric actuator in a direction in which the second piezoelectric actuator is contracted.
8. The temperature-sensing piezoelectric dispenser of claim 7 , wherein the first returning unit and the second returning unit are springs that are installed in the pump body and apply an elastic force to the first piezoelectric actuator and the second piezoelectric actuator.