KR102467695B1 - Application nozzle head and liquid application apparatus having it - Google Patents

Abstract

[Problem] Provision of a displacement expanding mechanism capable of controlling the application of a high-viscosity liquid material at high speed and stably, and a liquid application device having the same.
[Solution] A nozzle hole for discharging liquid material, a supply passage for supplying the liquid material to the nozzle hole, a plunger reciprocating in contact with the liquid in the supply passage, and a displacement expanding mechanism for imparting displacement to the plunger; , A liquid application device including an actuator for imparting displacement to the displacement expanding mechanism, wherein at least one of a contact portion between the displacement expanding mechanism and the actuator is a curved surface.

Description

Application nozzle head and liquid application device having the same {APPLICATION NOZZLE HEAD AND LIQUID APPLICATION APPARATUS HAVING IT}

The present invention relates to an application nozzle head and a liquid application device having the same. In particular, it relates to an application nozzle head for discharging a high-viscosity liquid and a liquid application device having the same.

BACKGROUND OF THE INVENTION [0002] A device for discharging liquid material by reciprocating motion of a plunger is known. For example, it is a jet-type liquid application device shown in Patent Document 1.

In recent years, high-speed application work has been required from the viewpoint of improving productivity. In this type of liquid application device, there is a growing demand for further increasing the number of discharges within a certain period of time. Therefore, it is necessary to reciprocate the plunger of the liquid application device at high speed.

As a driving source for reciprocating the plunger, an actuator such as a motor, air, or a piezoelectric element is often used. Piezoelectric elements are capable of high-speed operation. However, since the amount of displacement is small, it is common to increase the amount of displacement in combination with a displacement magnifying mechanism. For example, what was described in patent document 2 is known.

Hereinafter, a conventional liquid application device using the displacement increasing mechanism and a piezoelectric element will be described with reference to FIGS. 1 to 4 .

A front view of a conventional liquid application device is shown in FIG. 1 . A cross-sectional view of a discharge portion of a conventional liquid application device is shown in FIG. 2 . The liquid application device 1 ejects ejection liquid droplets 65 from a nozzle hole 60 . The liquid application device 1 includes a supply passage 52 communicating with a nozzle hole 60 and supplying a liquid material, a plunger 12a whose tip reciprocates in the supply passage 52, and a plunger 12a. and an actuator 2a for reciprocating, and a displacement increasing mechanism 3a.

The actuator 2a is arranged symmetrically and the displacement increasing mechanism 3a is composed of elastically deformable U-shaped members 5, 6, 7, 8 and 9 to which the plunger 12a is connected to the lower portion. In Fig. 3, the operation when the plunger 12a rises is explained. In Fig. 4, the operation when the plunger 12a is lowered is explained. The actuator 2 moves the plunger 12 upward by applying a force to separate the ends of the U-shaped members 5, 6, 7, 8 and 9 apart. Conversely, the actuator 2a applies a force to bring both ends of the U-shaped members 5, 6, 7, 8, and 9 closer, thereby moving the plunger 12a downward.

Japanese Unexamined Patent Publication No. 10-314640 Japanese Unexamined Patent Publication No. 2015-051399

In order to discharge the high-viscosity liquid material, it is necessary to drive the plunger 12 at high speed with a large displacement.

In the conventional displacement increasing mechanism 3a, the plunger 12a is reciprocated in the vertical direction by elastically deforming the U-shaped members 5, 6, 7, 8 and 9. In order to secure the necessary amount of displacement, it is necessary to lower the rigidity of the U-shaped members 8 and 9. Accordingly, the natural frequency is lowered, and there is a limit to improving the displacement response speed of the plunger 12.

Accordingly, the amount of displacement of the plunger 12a can be increased by increasing the displacement expansion ratio of the displacement increasing mechanism 3a relative to the displacement of the actuator 2, but compatibility with high-speed driving is difficult.

The present invention is to solve these conventional problems, and to provide a displacement expansion mechanism, an application nozzle head including the same, and a liquid application device including the same, which can control the application of a high-viscosity liquid material at high speed and stably. are doing

To achieve the above object, a nozzle hole for discharging the liquid material, a supply passage for supplying the liquid material to the nozzle hole, a plunger reciprocating in contact with the liquid in the supply passage, and a displacement for imparting displacement to the plunger. A liquid application device comprising an enlargement mechanism and an actuator for imparting displacement to the displacement enlargement mechanism, wherein at least one of contact portions of the displacement enlargement mechanism and the actuator is a curved surface.

According to the configuration of the present invention, in industrial applications such as manufacturing of electronic devices, it is possible to control the application of a high-viscosity liquid material containing functional particles at high speed and stably, and to apply an optimal amount to a required location in an arbitrary pattern. can do.

1 is a front view of a conventional liquid application device
Figure 2 is a cross-sectional view of the discharge portion of the conventional liquid application device
3 is an explanatory view of an operation when a plunger of a conventional liquid application device rises;
4 is an explanatory view of the operation of a conventional liquid application device when the plunger is lowered;
5 is a cross-sectional view of the liquid application device of the embodiment of the present invention
6A is a cross-sectional view of the plunger tip of an embodiment of the present invention.
6B is a cross-sectional view of the plunger tip of an embodiment of the present invention.
6C is a cross-sectional view of the plunger tip of an embodiment of the present invention.
6D is a cross-sectional view of the plunger tip of an embodiment of the present invention.
6E is a cross-sectional view of the plunger tip of an embodiment of the present invention.
6F is a cross-sectional view of the plunger tip of an embodiment of the present invention.
Fig. 7 is a cross-sectional view of the liquid application device of the embodiment of the present invention;
8A is a cross-sectional view of a liquid application device of an embodiment of the present invention;
8B is a cross-sectional view of the liquid application device of the embodiment of the present invention.
8C is a cross-sectional view of the liquid application device of the embodiment of the present invention.
9A is a plunger displacement behavior diagram of an embodiment of the present invention
9B is a cross-sectional view of the liquid application device of the embodiment of the present invention.
9C is a cross-sectional view of the liquid application device of the embodiment of the present invention.
9D is a cross-sectional view of the liquid application device of the embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is described using drawings. Since the description is an example, the present invention is not limited to the following description.

<Liquid application device>

<Configuration>

Fig. 5 is a cross-sectional view of the liquid application device 100 of the embodiment of the present invention, and the basic configuration will be described below.

The liquid application device 100 ejects ejection droplets 65 of the liquid material from the nozzle hole 60 . The liquid application device 100 includes a supply passage 52 communicating with the nozzle hole 60 and supplying the liquid material, a plunger 12 whose tip reciprocates in the supply passage, and the plunger 12 for reciprocating operation. It is provided with an actuator (2) and a displacement expansion mechanism (3).

Hereinafter, the characteristics of each component will be described.

<Nozzle hole (60)>

The nozzle hole 60 is a through hole provided in a metal such as cemented carbide, stainless steel, aluminum, or titanium. The material may be not only metal but also ceramic or resin materials such as PEEK. However, when the liquid material is discharged, it is necessary to select a material that is not abraded by the containing particulate material or eroded/eluted by the liquid material.

In addition, according to the size of the ejected droplet, the inner diameter of the nozzle is selected in the range of Φ 0.05 mm to 0.5 mm. Depending on physical properties such as viscosity of the liquid material, thixotropy, surface tension, and contact angle with the nozzle surface, the nozzle length is selected in the range of 0.05 mm to 5 mm.

In FIG. 5, the supply flow path 52 and the nozzle hole 60 are shown as an integral structure for simplification. However, for ease of manufacture and improved maintenance, the nozzle hole 60 may be separately manufactured and assembled as a separate part.

<Supply flow path 52>

The same material as the nozzle hole 60 can be used for the supply passage 52 . The cross section of the supply passage 52 may be a circular shape of about Φ 0.5 to 10 mm or a rectangular shape of the same cross-sectional area. A circular shape is preferable from the viewpoints of workability and prevention of bubble pooling.

The supply passage 52 communicates the nozzle hole 60 with a tank (not shown) for supplying the liquid material. The supply flow passage 52 plays a function of supplying the liquid material filled in the tank to the nozzle hole 60 .

<Plunger (12)>

The plunger 12 moves through the hole of the guide 110 and the sealing material 104 . In this way, the liquid material is pushed out of the nozzle hole 60 in the supply passage 52 . For the plunger 12, the same material as for the nozzle hole 60 can be used. However, as for the material of the plunger 12, it is necessary to select a material that is not abraded and degraded by particles contained in the guide 110, the sealant 104, and the liquid material, or corroded or dissolved in the liquid material. . In addition, in order to drive the plunger 12 at high speed, it is preferable to select a material having a low specific gravity. Furthermore, it is preferable to reduce the weight by reducing the volume of the plunger 12 itself to a minimum.

The plunger 12 serves a function of converting the drive energy of the actuator 2 into discharge energy of the liquid material. When the plunger 12 reciprocates in the vicinity of the nozzle hole 60, a pressure is applied to the liquid material near the nozzle hole 60, and the discharge liquid droplets 65 of the liquid material are discharged from the nozzle hole 60.

The tip shape of the plunger 12 may be a flat shape as described in FIG. 5 or a convex shape as described in FIGS. 6A to 6F.

<Guide (110)>

The guide 110 moves the plunger 12 straight up and down. The guide 110 has a through hole, and the plunger 12 moves up and down the through hole.

<Actuator (2)>

The actuator 2 is used as a driving source for reciprocating the plunger 12, and a motor, air, piezoelectric element or the like is often used.

<Displacement expansion mechanism (3)>

The displacement increasing mechanism 3 is preferably selected from a material that can achieve both abrasion resistance and light weight, such as the plunger 12, and is composed of a support portion 101 and a lever 102.

The displacement magnifying mechanism 3 is in charge of a function of enlarging the displacement amount of the plunger 12 more than the displacement amount of the actuator 2 . By reciprocating the plunger 12 with a larger size using the smaller actuator 2, a highly viscous liquid material or a liquid material containing large particles can be ejected from the nozzle hole 60.

5, the lever 102 is installed on the support portion 101 that comes into contact with the housing 30, and the plunger 12 is maintained in contact with the end of the lever 102 by the tensile force of the elastic body 103. . It does not matter if this elastic body 103 is installed between the plunger 12 and the housing 30 and is held by the compressive force.

The elastic body 103 may be either a spring coil spring or a leaf spring. The spring constant is preferably selected in the range of 0.1 to 10 N/mm. If the spring constant is too small, the natural frequency is low, making it impossible to drive at high speed, and if the spring constant is too large, the change in spring force according to the displacement of the actuator is large, resulting in unstable driving.

<Contact between lever 102 and actuator 2>

At least one of the contact portions of the lever 102 and the actuator 2 is configured as a curved surface. Accordingly, the actuator 2 may contact the upper surface of the lever 102 to apply displacement. The lever 102 rotates around the fulcrum 101 . With this rotation, the plunger 12 provided at the tip of the lever 102 can reciprocate up and down according to the displacement of the actuator 2.

Moreover, in order to reduce the sliding resistance of the contact part of the lever 102 and the actuator 2, at least any one of contact surfaces may have a concavo-convex shape. That is, either concave shape or convex shape may exist.

<Contact surface between fulcrum 101 and lever 102>

The fulcrum portion 101 has a cylindrical shape. The tip of the lever 102 contacts the working point 109 of the flange plane of the plunger 12 with a convex curved surface. Further, it is preferable that the portion of the lever 102 in contact with the fulcrum portion 101 is a concave curved surface having a radius of curvature equal to or greater than the radius of curvature of the fulcrum portion 101 in contact. It does not matter even if these are integral component configurations. Moreover, a concave part and a convex part may have an opposite relationship.

Here, the center of rotation around the support portion 101 of the lever 102 is the support point 107, the contact surface between the lever 102 and the actuator 2 is the power point 108, and the lever 102 is the plunger ( 12) is taken as the action point 109.

As described in Fig. 5, the point 107, the force point 108, and the point of action 109 do not lie on the same straight line and form a triangle.

In Fig. 5, the actuator 2 and the plunger 12 are located in the same direction with respect to the point 107 serving as the center of rotation of the lever 102, but they may be located in different directions.

It is important to keep the distance L1 from the point 107 to the power point 108 smaller than the distance L2 from the point 107 to the point of action 109. Accordingly, it becomes possible to enlarge the displacement of the plunger 12 larger than the displacement of the actuator 2.

In addition, when the actuator 2 is a piezoelectric element, it is also possible to apply a preload of a compressive load by means of the elastic body 103 in order to prevent the piezoelectric element from being destroyed by a tensile force. As a result, the driving reliability of the actuator 2 can be improved.

<Applying operation>

Next, the application operation of the liquid material will be described below.

(1) Supply of liquid material

When the tip of the plunger 12 moves upward in the supply passage 52 filled with the liquid material, the liquid material is supplied near the nozzle hole 60 . By applying a back pressure of about 0.1 to 500 kPa to a liquid material supply tank (not shown) directly connected to the supply flow path 52, the supply speed of the liquid material is increased and the high viscosity material can be applied at a shorter discharge interval. The higher the back pressure, the higher the supply rate of the liquid material. However, in the case of a particle-containing paste material, separation of the solid and liquid components becomes a problem, so the back pressure is preferably about 300 kPa or less. In addition, even if the back pressure is 300 kPa or less, if the liquid material exudes from the nozzle hole 60, the gas-liquid interface (meniscus surface) in the nozzle hole 60 may become unstable and stable droplet discharge may not be possible. , it is indispensable to set the back pressure according to the liquid material and discharge conditions.

(2) liquid discharge

When the plunger 12 moves downward closer to the nozzle hole 60, the liquid pressure in the vicinity of the nozzle hole 60 rises and ejection droplets 65 of the liquid material are ejected. Here, the sealant 104 is installed in close contact with the plunger 12 and the housing 30 so that the liquid pressure in the vicinity of the nozzle hole 60 does not decrease even during the vertical movement of the plunger 12 . The faster the downward moving speed of the plunger 12 is, the faster the nozzle pressure can be increased. For this reason, the discharge speed of the liquid material protruding from the nozzle hole 60 at the head can be increased. Furthermore, by rapidly moving the plunger 12 upward after the first liquid material starts to protrude from the nozzle hole 60, the ejection speed of the succeeding liquid material can be rapidly reduced. Accordingly, even with a high-viscosity liquid material, it is possible to shorten the elongation of the ejected liquid droplet like a thread, and a smaller amount of the ejected liquid droplet 65 can be stably ejected.

In FIG. 5, the tip of the plunger 12 contacts the liquid material in the supply passage 52 and moves up and down. However, as shown in FIG. 7, the tip of the plunger 12 directly contacts the liquid material. It is also possible to adopt a configuration in which the surface of the diaphragm 105 is moved up and down without being moved.

FIG. 7 is a cross-sectional view of a modified example of the liquid applying device 100 of FIG. 5 . The plunger 12 is located on the upper surface of the diaphragm 105. The plunger 12 pushes and pulls the diaphragm 105.

<Modified Example 1 of Displacement Expanding Mechanism 3>

Next, a modified example of the displacement increasing mechanism 3 will be described below.

8A shows the same basic configuration as the liquid application device 100 described above. Marked for comparison. Here, as shown in Fig. 8B, a curved bearing 106 may be provided on the side of the actuator 2 that does not come into contact with the lever 102.

By adopting such a configuration, the force in the short axis direction (left and right direction in Fig. 8A) does not act on the actuator 2, and driving reliability can be improved.

<Modified Example 2 of Displacement Expanding Mechanism 3>

In addition, in the displacement increasing mechanism 3, in order to improve the displacement response speed of the plunger 12 and continuously drive it for a long period of time, the actuator 2, the lever 102, the support portion 101, and the plunger 12 It is necessary to reduce the driving resistance of the sliding portion.

So, as shown in FIG. 8C, the contact surface of the actuator 2 and the lever 102 and the contact surface of the lever 102 and the fulcrum 101 do not overlap when viewed from the long axis direction of the actuator 2 , the reaction force received when the lever 102 is driven can be reduced, and it becomes possible to suppress excessive sliding resistance. That is, the surface where the lever 102 and the fulcrum portion 101 come into contact with each other is not included in the dotted line in FIG. 8C.

Furthermore, it is also possible to reduce the sliding resistance by reducing the contact area by forming irregularities or grooves of 0.1 μm or more on one or both of the sliding surfaces.

In addition, in order to reduce the sliding resistance of the contact interface, it is more preferable to apply and form a solid lubricant or grease.

<Modified Example 3 of Displacement Expanding Mechanism 3>

9A shows the relationship between the displacement of the plunger 12 and time. Ideally, it is ideal that the plunger 12 displaces like the ideal curve. However, in reality, a response delay of time occurs, and the plunger 12 is displaced according to the actual displacement curve. In particular, when a highly viscous liquid material is discharged, an actual displacement curve is obtained. This remarkably occurs because the driving resistance of the plunger 12 increases when a large displacement is applied to the plunger 12 .

These two main factors are:

(1) This is because the pressure near the nozzle hole 60 at the tip of the plunger 12 increases as the tip of the plunger 12 approaches the nozzle hole 60.

(2) This is because the tensile force and compressive force by the elastic body 103 increase as the displacement of the actuator 2 alone or the displacement expansion magnification increases.

As a countermeasure for this, as an embodiment, as shown in Fig. 9B, it is preferable that the surface where the actuator 2 and the lever 102 abut are constituted by curved surfaces having different radii of curvature. 9B is a cross-sectional view of a modified example of the liquid application device 100.

In the case where the contact surface on the lever 102 side is a convex curved surface in the surface of the actuator 2 in contact with the lever 102, the radius of curvature of the surface on the actuator 2 side is It is preferable to set it as the structure made smaller than the radius of curvature. On the other hand, when the abutting surface on the lever 102 side is a concave curved surface, it is preferable to make the radius of curvature of the surface on the lever 102 side larger than the radius of curvature of the surface on the actuator 2 side.

FIG. 9C is a cross-sectional view of a modified example of the liquid applying device 100, which is a cross-sectional view of the liquid applying device 100 at the start of lowering of the plunger 12. As shown in FIG. 9D is a cross-sectional view of a modified example of the liquid applying device 100, which is a cross-sectional view of the liquid applying device 100 at the end of the lowering of the plunger 12. As shown in FIG. 9C, when the plunger 12 starts to descend, the distance (arrow) between the power point at which the actuator 2 presses the lever 102 and the point 107 becomes relatively short and the displacement expansion becomes larger. It becomes possible to speed up the rise of displacement response more. In addition, as shown in FIG. 9D, at the end of the descent of the plunger 12, the distance (arrow) between the power point at which the actuator 2 presses the lever 102 and the point 107 (arrow) becomes relatively long and the displacement expansion becomes smaller. For this reason, the pressing load of the plunger 12 can be made into a larger force, and it becomes possible to speed up the displacement response more without losing to the drive resistance of the plunger 12.

In this case, the length of the arrow changes when the plunger 12 moves downward, so that the displacement enlargement magnification of the displacement enlargement mechanism 3 can be changed slowly and small.

<Modified Example 4 of Displacement Expanding Mechanism 3>

Further, in order to eject a small amount of the high-viscosity liquid material, it is important to drive the plunger 12 at high speed with a relatively small displacement and a large force. To this end, it is necessary to reduce the weight of the lever 102 by reducing the mass of the lever 102 to a minimum by suppressing the displacement enlargement magnification of the displacement enlargement mechanism 3 to a minimum necessary.

However, since the actuator 2 and the elastic body 103 do not interfere, the design range is limited. This is the same even when the elastic body 103 is installed between the plunger 12 and the housing 30 and is held by a compressive force.

As an embodiment of this countermeasure, a cross-sectional view of a modified example of the liquid application device 100 is shown in FIG. 10 . As shown in FIG. 10, the displacement direction of the actuator 2 has an inclination θ with respect to the displacement direction of the plunger 12. This inclination (θ) is often selected in the range of 1 degree to 90 degrees, and is most effective in the range of 10 to 60 degrees. 10 is a state before the plunger 12 is operated.

When the plunger 12 is actuated, the displacement direction of the actuator 2 is inclined with respect to the displacement direction of the plunger 12 .

With this configuration, the actuator 2 and the lever 102 contact surface and the lever 102 and the support portion 101 contact surface do not overlap when viewed from the long axis direction of the actuator 2. The distance between the point 107 and the power point 108 in the direction orthogonal to the displacement direction of ) can be set smaller.

Furthermore, since the physical distance between the actuator 2 and the elastic body 103 is increased, the length of the lever 102 can be shortened.

Therefore, the weight of the lever 102 can be reduced, and the moment of inertia of the movable parts such as the lever 102 and the plunger 12 can be reduced by about 50% to 90%.

When a predetermined torque is applied, since the displacement acceleration is inversely proportional to the moment of inertia, it becomes possible to increase the displacement acceleration of the plunger 12 by a factor of 2 to 10 times, which is useful for discharging a small amount of a high-viscosity liquid material.

In Fig. 10, the actuator 2 and the plunger 12 are located in the same direction with respect to the point serving as the center of rotation of the lever 102, but they may be located in different directions.

The liquid application device of the present invention can control application of a liquid material containing functional particles at high speed and stably. In addition, the liquid application device of the present invention can apply an optimum amount to a required location in an arbitrary pattern at high speed without contact.

The liquid application device of the present invention can be used for manufacturing electronic devices indispensable for continuous long-term driving. In addition, the liquid application device of the present invention is provided with a displacement expansion mechanism for applying an arbitrary pattern for the purpose of 3D coating on a three-dimensional structure such as an uneven surface or a curved surface, or productivity improvement in manufacturing a variety of small quantities of electronic devices. It is preferably used as a liquid application device for

1: liquid application device 2, 2a: actuator
3, 3a: displacement enlargement mechanism 5: female member
8: female member 12, 12a: plunger
30: housing 52: supply flow path
60: nozzle hole 65: discharge droplet
100: liquid application device 101: support portion
102: lever 103: elastic body
104: seal material 105: diaphragm
106: bearing 107: fulcrum
108: power point 109: action point
110: guide

Claims (11)

a nozzle hole through which liquid material is discharged;
a supply passage for supplying a liquid material to the nozzle hole;
A plunger reciprocating in contact with the liquid in the supply passage;
a displacement increasing mechanism for imparting displacement to the plunger;
An actuator for imparting a displacement to the displacement magnifying mechanism;
At least one of the contact portions of the displacement expanding mechanism and the actuator is a curved surface;
The displacement expanding mechanism has a lever portion and a support portion,
and a distance between a power point at which the actuator presses the lever portion and a fulcrum that is a center of rotation of the lever portion around the fulcrum portion changes when the lever portion rotates around the fulcrum portion. The method of claim 1,
The liquid application device further has an elastic body connected with the plunger. delete The method of claim 1,
The liquid application device, wherein the support portion has a curved surface. The method of claim 1,
A point serving as a center of rotation around the fulcrum portion of the lever unit and a power point serving as a contact surface between the lever unit and the actuator;
The action point, which is the contact surface between the lever part and the plunger,
A liquid application device that does not exist on the same line. The method of claim 1,
The liquid application device, wherein at least one of the contact surfaces of the displacement increasing mechanism and the actuator has a concavo-convex shape. The method of claim 1,
In the contact surface between the displacement expanding mechanism and the actuator,
a radius of curvature of the contact surface on the side of the displacement expanding mechanism;
The liquid application device, wherein the radii of curvature of the contact surface on the actuator side are different. The method of claim 7,
A radius of curvature of the contact surface on the displacement increasing mechanism side is smaller than a radius of curvature of the contact surface on the actuator side. The method of claim 1,
The liquid application device according to the operating position of the plunger, the position of the contact point between the displacement increasing mechanism and the actuator changes. The method of claim 1,
The liquid applying device, wherein a displacement direction of the actuator has an inclination with respect to a displacement direction of the plunger. The method of claim 1,
A liquid application device using a piezoelectric element for the actuator.

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