Coating nozzle head, and liquid-applying apparatus including the same

1. A liquid-coating apparatus, comprising:

(a) a nozzle hole from which a liquid material is to be discharged;

(b) a supply flow channel configured to supply the liquid material to the nozzle hole;

(c) a plunger configured to reciprocate in contact with the liquid material inside the supply flow channel;

(d) a displacement-expansion mechanism configured to displace the plunger; and

(e) an actuator configured to displace the displacement-expansion mechanism,

wherein:

the displacement-expansion mechanism includes a lever and a pivot point part supporting the lever;

each of a first contact part of the lever and a corresponding contact part of the actuator has a curved surface;

each of a second contact part of the lever and a corresponding contact part of the pivot point part has a curved surface;

a curvature of the first contact part of the lever is smaller than a curvature of the corresponding contact part of the actuator;

a curvature of the second contact part of the lever and a curvature of the corresponding contact part of the pivot point part are the same;

the displacement-expansion mechanism is at a first end of the actuator;

a bearing is at a second end of the actuator opposite to the first end of the actuator;

a curvature of the bearing and a curvature of a corresponding contact portion of the second end of the actuator are the same;

the liquid-coating apparatus is configured to change a distance between a pivot point of the pivot point part and a longitudinal axis of the actuator including a point of effort;

the pivot point of the pivot point part is a rotation center of the lever; and

the point of effort is a contact point between the lever and the actuator.

2. The liquid-coating apparatus according to claim 1 , further comprising an elastic member that is connected to the plunger.

3. The liquid-coating apparatus according to claim 1 , wherein:

a point of load is a contact point between the lever and the plunger; and

the pivot point, the point of effort and the point of load are noncollinear.

4. The liquid-coating apparatus according to claim 1 , wherein at least one of the first contact part of the lever, the second contact part of the lever, the corresponding contact part of the actuator, and the corresponding contact part of the pivot point part has at least one of a recession, a projection and a groove defined therein.

5. The liquid-coating apparatus according to claim 1 , wherein the liquid-coating apparatus is configured to vary a position of a contact point between the displacement-expansion mechanism and the actuator with movement positions of the plunger.

6. The liquid-coating apparatus according to claim 1 , wherein there is an inclination angle between a displacement direction of the plunger and a displacement direction of the actuator.

7. The liquid-coating apparatus according to claim 1 , wherein the actuator is a piezoelectric element.