JP4870800B2 - Nozzle for liquid dispensing device - Google Patents

Description

The present invention relates to a nozzle suitable for use in any liquid dispensing apparatus including viscous fluids, viscous substances, and the like.

For example, in a semiconductor manufacturing process, a liquid dispensing apparatus is used to apply an electronic material such as a paste on a substrate regularly or irregularly for point application, linear application, or the like. In such a liquid dispensing apparatus, the amount of liquid pushed out from the liquid storage container by a pressurizing means such as a piston is controlled by the opening / closing amount and opening / closing time of the discharge valve. There are various types of such discharge valves, and appropriate discharge valves are properly used depending on the type of liquid to be discharged, the amount of liquid to be discharged per unit time, and the like.
In particular, a discharge valve called a needle valve is provided with a needle valve body having an acute tip provided movably in a liquid chamber and a tip of the needle valve body, and a small opening leading to a discharge port is provided in the center. The needle seat is configured to stop the liquid discharge when the tip of the needle valve body closes the opening in the central portion of the valve seat and to discharge the liquid by moving away from the opening. It has the characteristic that the change in the effective sectional area of the valve seat opening with respect to the fine stroke adjustment of the valve body is small, and because of this characteristic, it is said that it is suitable for a small amount of liquid discharge.

However, when liquid dispensing is performed using such a needle valve, after applying a nozzle (ultrafine tube) suitable for various discharge operations to the valve discharge port, operations such as coating and filling are performed. The current situation is.
When performing liquid dispensing with such a nozzle, especially when performing high-viscosity liquid ejection, the valve is closed when the valve is opened and closed to control liquid ejection. A phenomenon in which liquid discharge continues from the tip of the ultrathin tube (referred to as sag) is noticeable.
It has been confirmed that such a phenomenon occurs regardless of whether or not bubbles are mixed in the liquid. The main cause is in the pipe from the valve seat to the nozzle opening end that is the discharge end port. It is considered that the resistance induces the residual pressure phenomenon of the liquid pressurization necessary for ejection and the liquid is ejected until the residual pressure is eliminated.
When such a phenomenon is seen from the viewpoint of the coating operation, it appears as poor liquid shortage immediately after ejection. In particular, when discharging a highly viscous liquid material, a problem called stringing occurs when moving an ultra-thin tube from one application point to another application point, resulting in a problem that the applied work becomes dirty and becomes defective. was there.

  The main object of the present invention is to solve the problems of the conventional apparatus that carries out the liquid dispensing with the above-mentioned nozzles. In particular, it solves the problems associated with liquid breakage and leakage at once. Another object of the present invention is to provide a nozzle for a liquid fixed quantity discharge device capable of performing fine liquid discharge and stop with high accuracy.

As a result of diligent research to achieve the above object, the present inventor has made it possible to make the nozzle itself function as a needle valve in order to make the best use of the excellent characteristics of the needle valve. It is no longer necessary to attach a nozzle (ultra-thin tube) to the valve discharge port as in the case of a fixed-quantity discharge device, and we have obtained knowledge that the problems associated with liquid breakage and leakage can be solved. The present invention has been conceived.
That is, the present invention is a nozzle for a liquid fixed quantity discharge device that discharges and stops discharge of pressurized liquid introduced into a liquid storage unit, and includes a valve mechanism in a nozzle body that communicates with the liquid storage unit. It is a nozzle characterized by .

In the nozzle, the nozzle body and the inner wall surface of the bowl-shaped, and a cylindrical discharge holes proximal to the tip of the inner wall surface of the bowl-shaped articulating and a valve mechanism provided in the discharge hole near Yes.
Further, the valve mechanism, and perforated a valve body which is provided movably within the nozzle body, is formed at the distal end of the inner wall surface of the bowl-shaped of the nozzle body and a valve seat located in the vicinity of the discharge hole Yes.
Furthermore, the valve body has a distal portion whose outer diameter decreases monotonously toward the tip is formed in a needle shape, the outer peripheral surface of the tip of the inner wall surface of the bowl-shaped of the nozzle body is smaller forms an angle with respect to the axial direction than the inner wall surface so as to respect the valve seat of the tip in close contact on a generally circular contact line or contact surface.
And the said discharge hole is formed short so that the front-end | tip of the said valve body may be located in the opening end of the discharge hole rather than the said valve seat in the discharge hole at the time of valve closing.

According to the nozzle of such a present invention, a valve mechanism for discharging and the discharge stop of the liquid Rutotomoni provided in the nozzle body, in the vicinity of the valve seat short cylindrical discharge hole discharge port to become liquid for the valve mechanism since was positioned, can be formed in substantially the same position and the position of the valve closing position and the discharge hole, moreover, as to directly and physically opens and closes the discharge hole in the valve body, the valve when the valve is closed Since the tip of the body is positioned closer to the opening end of the discharge hole than the valve seat in the discharge hole, it is possible to stop the discharge quickly with excellent fluidity and completely prevent any unexpected leakage of liquid thereafter prevented can be, thereby Ru can eliminate problems such as in the prior art dripping or stringing the completely.
Furthermore, according to the nozzle of the present invention, as described above, the valve opening / closing position and the discharge hole position can be formed at substantially the same position, and the discharge hole is directly and physically formed by the valve body. When the valve is closed, the tip of the valve body is positioned closer to the opening end of the discharge hole than the valve seat in the discharge hole, and when the valve is opened, the liquid discharge direction is guided by the cylindrical discharge hole. The liquid can be quantitatively discharged in a desired shape at high speed and with high accuracy.
In the nozzle of the present invention, the angle of the outer peripheral surface of the distal end portion of the nozzle body between the proximal end and the distal end of the outer peripheral surface is smaller on the distal end side than on the proximal end side. It is preferable to form in the shape of a truncated cone.

It is the schematic which shows embodiment of the nozzle of this invention. It is a figure which shows the example which act | operated the nozzle of this invention with pressurized air.

Hereinafter, embodiments of the nozzle of the present invention will be described with reference to the accompanying drawings. This embodiment is an example in which a needle-like valve body that opens and closes a valve is operated by an air cylinder.
FIG. 1 is a sectional view schematically showing a main part of a nozzle according to the present invention, and FIG. 2 is an explanatory diagram for explaining a valve device using the nozzle.
In FIG. 1, reference numeral 10 denotes a nozzle body, and a cylindrical discharge hole 12 for discharging a liquid is provided at the lower end of the nozzle body. Inside the nozzle body 10, with a needle-shaped valve element 14 which is movable in the vertical direction are disposed, the proximal end of the discharge hole 12 on the inner wall surface in the vicinity (the upper end in the figure), the valve element 14 A valve seat 16 is provided, and the valve body 14 and the valve seat 16 form a valve mechanism. That is, the distal end (lower end in the figure) of the inner wall surface of the nozzle body 10 is connected to the proximal end of the discharge hole 12 , and the distal end of the inner wall surface is provided with a function as the valve seat 16. by the outer circumferential surface of the part 18 is in line contact or surface contact, because the valve closed, the discharge of the liquid is stopped, whereas, by such contact is released, it becomes the state of valve opening, the liquid The discharge is started.

  In the nozzle according to the present invention, the contact position between the needle-like valve body 14 and the valve seat 16, that is, the valve opening / closing position is formed in the vicinity of the liquid discharge hole 12. The position and the discharge hole position can be formed to be substantially the same. Details will be described below.

The valve body 14 is formed an outer diameter d is substantially equal elongated cylindrical in its upper part, at its distal end 18, decreased hand outer diameter d is monotonously as it approaches the tip, forming a needle-shaped as a whole . Further, the inner wall surface of the nozzle body 10 is formed in a tubular shape up to the vicinity of the central portion thereof, but is formed in a mortar shape from which the tube diameter monotonously decreases, and is connected to the base end of the discharge hole 12. The tip is formed so as to function as the valve seat 16.
More specifically, in order for such a valve body 14 and the inner wall surface of the nozzle body 10 to have a valve function, the tip of the valve body 14 in a cross section parallel to the axial direction of the nozzle body 10 in the vicinity of the discharge hole 12. The portion 18 and the inner wall surface of the nozzle body 10 need to be formed with different angles with respect to the axial direction. In this embodiment, the angle formed with the distal end portion 18 of the valve body 14 with respect to the axial direction. but the inner wall surface of the nozzle body 10 is formed smaller than the angle θ which forms with respect to the axial direction, in the state of the valve closed, the tip of the inner wall surface of the outer peripheral surface and the nozzle body 10 of the tip 18 of the valve element 14 However, they are in close contact with each other on a substantially circular contact line or contact surface in a plane perpendicular to the nozzle axis direction. Moreover, by changing the angle with respect to the axial direction of the outer peripheral surface of the front- end | tip part 18 of such a valve body 14 and the inner wall face of the nozzle main body 10, from the opening end (lower end in the figure) to a valve opening / closing position. It is possible to adjust the distance to the contact surface, i.e., the valve seat 16 , which can be formed substantially at the same position, and the front end of the valve body 14 is within the discharge hole 12 when the valve is closed. , Ru can be so positioned on the open end side of the discharge port 12 than the valve seat 16.
The material of the nozzle body 10 and the needle-like valve body 14 constituting the nozzle may be any material that can perform the valve function, but an appropriate material is selected from the viewpoint of sealing performance, processing accuracy, durability, and the like. For example, by forming either the nozzle body 10 or the valve body 14 with a soft material such as resin or brass and forming the other with a hard metal material, the sealing performance can be improved. .

Here, an example will be described in which the nozzle body 10 having the valve function configured as described above is attached to the liquid dispensing apparatus.
As shown in FIG. 2, the nozzle body 10 according to the present invention is attached as a part of the valve device 20 of the liquid dispensing apparatus. The valve device 20, the inlet hole 22 of the liquid introduced through the flow path from the liquid reservoir (not shown), and an outlet hole 24 communicating with the nozzle body 10 is provided, the nozzle body from the inlet hole 22 The space up to the discharge hole 12 at the tip constitutes the liquid storage portion 26.

The valve body 14 constituting the nozzle of the present invention has a front end portion 18 positioned in the vicinity of the discharge hole 12 of the nozzle body 10 and a rear end portion connected to a piston 30 of a cylinder 28 as described later, thereby It can be moved forward and backward in the vertical direction.
The cylinder itself is a known one, and for example, a double acting type can be adopted. In this case, each port is connected to an air source 34 via an electromagnetic switching valve 32. That is, the pressurized air supplied from the air source 34 is supplied to one of the ports by the control switching signal s sent from the control means (not shown) to the electromagnetic switching valve 32, and thereby the needle-like valve body. 14 movements are configured to be controlled.

In the valve device configured as described above, when the liquid is dispensed, the signal s is output from the control means (not shown) to the electromagnetic switching valve 32 so that the needle-like valve body 14 is moved upward. Switching is performed so that pressurized air is supplied to the other ports. Thereby, the valve body 14 is disengaged from the valve seat 16 and the discharge hole 12 is opened. At the same time, the liquid pressurized to the required pressure is specified from the discharge hole 12 in relation to the opening area thereof. The liquid can be discharged for a certain period of time, and the liquid can be discharged with a high accuracy without a time lag.
On the other hand, at the end of the fixed discharge, the upper port is pressurized so as to move the needle-like valve body 14 downward based on the discharge end signal s from the control means (not shown) to the electromagnetic switching valve 32. Switching is performed so that air is supplied. As a result, the needle valve body 14 quickly descends and comes into contact with the valve seat 16, and the discharge hole 12 is mechanically and reliably closed by the needle valve body 14. Accordingly, the discharge of the liquid from the discharge hole 12 is completely stopped when the needle valve body 14 and the valve seat 16 come into contact with each other, and the possibility of liquid leakage while the nozzle is closed is sufficiently removed. become.

As described above, the nozzle body and the needle-like valve body constituting the nozzle of the present invention have extremely small dimensions and volume, and are always retracted smoothly and quickly regardless of the liquid pressure. Ascending) and advancing (decreasing) to open and close the discharge hole 12, an excellent responsiveness is realized in addition to the reliability of valve opening and closing.
Further, in the illustrated nozzle, in order to further improve the liquid drainage when the discharge hole 12 is closed, the length of the discharge hole 12 protruding downward from the valve seat 16 where the needle-like valve body 14 is seated is set. In addition, when the valve is closed, the tip of the valve body 14 is positioned closer to the opening end of the discharge hole 12 than the valve seat 16 in the discharge hole 12 so that the valve element 14 is still closed after the discharge hole 12 is closed. The slight liquid that is expected to remain in the discharge hole is made substantially zero .

The liquid dispensing apparatus provided with such a valve mechanism is a nozzle that functions as a discharge valve when the work as the liquid application object is appropriately displaced in relation to the liquid discharge timing or the like. The position can be fixed for use.
However, when the work is positioned and fixed at a specific position, it is necessary to move the nozzle to a required position and direction. In such a case, the nozzle is attached to a rectangular coordinate type three-dimensional manipulator, and this manipulator is operated by a controller that outputs a position signal based on a signal from the control means, so that the nozzle discharge hole is three-dimensionally coordinated. It will bring it to the required position of the system. Such an apparatus can be used for, for example, a work that is tact-conveyed by a conveyor, and can provide excellent coating efficiency.

  In this embodiment, the air cylinder is used as the means for operating the needle-like valve body in the nozzle having the valve function of the present invention. However, the present invention is not limited to this, and hydraulic drive means and Various drive means such as an electric drive means and a magnetic drive means can be used, and the present invention can be applied to all types of liquid dispensing apparatus.

DESCRIPTION OF SYMBOLS 10 Nozzle main body 12 Discharge hole 14 Needle-shaped valve body 16 Valve seat
18 Tip 20 Valve device 22 Inlet hole 24 Outlet hole 26 Liquid container 28 Cylinder 30 Piston 32 Electromagnetic switching valve 34 Air source

Claims (2)

A nozzle for a liquid fixed quantity discharge device that discharges and stops discharge of pressurized liquid introduced into a liquid container,
A valve mechanism in the nozzle body communicating with the liquid containing portion,
The nozzle body has a mortar-shaped inner wall surface, and a cylindrical discharge hole whose base end is connected to the tip of the mortar-shaped inner wall surface,
The valve mechanism has a valve body movably provided in the nozzle body, and a valve seat formed at the tip of a mortar-shaped inner wall surface of the nozzle body,
The valve body has a tip portion whose outer diameter monotonously decreases as it approaches the tip, and is formed in a needle shape,
The outer peripheral surface of the tip of the valve body is closer to the axial direction than the inner wall so as to be in close contact with the valve seat at the tip of the mortar-shaped inner wall of the nozzle body on a substantially circular contact line or contact surface. The angle is reduced,
The nozzle is characterized in that the discharge hole is formed to be short so that when the valve is closed, the tip of the valve body is positioned closer to the opening end of the discharge hole than the valve seat in the discharge hole . The outer peripheral surface of the distal end portion of the nozzle body is formed in a truncated cone shape in which the angle with respect to the axial direction between the proximal end and the distal end of the outer peripheral surface changes so that the distal end side is smaller than the proximal end side. The nozzle according to claim 1, wherein

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