JP2005021893A - Nozzle for apparatus for fixed quantity of liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle for an apparatus for discharging a fixed quantity of liquid provided with a valve mechanism exhibiting improved anti-dripping property when discharge of liquid is stopped, and completely free from liquid leakage. <P>SOLUTION: The nozzle for the apparatus for discharging a fixed quantity of liquid discharges pressurized liquid introduced into a liquid containing part and stops discharge of the liquid and is provided with the valve mechanism in a nozzle body communicating with the liquid containing part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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 discharge port, operations such as coating and filling are performed. is the current situation.
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 the resistance in the pipe from the valve seat to the nozzle that is the discharge end port. It is considered that the liquid is discharged until the residual pressure phenomenon of the liquid pressurization necessary for the discharge is introduced and 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 liquid dispensing by attaching the above-mentioned nozzle, and in particular, solves 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 (extra-thin tube) to the discharge end, 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.
According to such a configuration, it is possible to completely eliminate the problems such as liquid dripping and stringing as in the conventional case, and it is possible to provide excellent liquid breakage and to completely prevent the subsequent unexpected leakage of liquid. be able to.

In the nozzle, it is preferable that the main body has a liquid discharge hole and a valve mechanism is provided in the vicinity of the discharge hole.
Moreover, it is preferable that the said valve mechanism is formed from the valve body provided in the nozzle main body so that a movement was possible, and the valve seat formed in the inner wall face near the said discharge hole.
Furthermore, it is preferable that the valve body has a tip formed in a needle shape and a peripheral surface of the tip is formed so as to be in close contact with the inner wall surface of the nozzle on a substantially circular contact line.
According to such a configuration, the open / close position of the valve and the position of the liquid discharge end port can be formed at substantially the same position, and the discharge end port can be directly and physically opened and closed. Therefore, the liquid can be quantitatively discharged in a desired shape at high speed and with high accuracy.

  As described above, according to the nozzle of the present invention, since the valve mechanism for discharging and stopping the discharge is provided in the nozzle body, the valve opening / closing position and the position of the liquid discharge hole are substantially the same. In addition, since the discharge hole can be directly and physically opened and closed, the discharge can be stopped quickly with excellent liquid drainage, and an unexpected leakage of the liquid thereafter. It is possible to completely prevent it from coming out.

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 liquid discharge hole 12 is provided at a lower end portion thereof. Inside the nozzle 10, a needle-like valve body 14 that is movable in the vertical direction is disposed, and a valve seat 16 that receives the tip of the valve body is provided on the inner wall surface near the discharge hole 12. The valve body 14 and the valve seat 16 form a valve mechanism. That is, a function as a valve seat 16 is imparted to a part of the inner wall surface near the discharge hole 12 of the nozzle 10, and the peripheral surface of the distal end portion of the valve body 14 is in line contact or surface contact therewith, thereby closing the valve. Therefore, the discharge of the liquid is stopped, and on the other hand, when such contact is released, the valve is opened and the discharge of the liquid 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 has an elongated cylindrical shape with an outer diameter d substantially equal at the upper part thereof, but has a needle shape such that the outer diameter d decreases monotonously as it approaches the tip. Further, the inner wall surface of the nozzle 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 the inner wall surface in the vicinity of the discharge hole functions as the valve seat 16. It is formed to do.
More specifically, in order for the valve body 14 and the inner wall surface of the nozzle 10 to have a valve function, in the cross section parallel to the axial direction of the nozzle 10 in the vicinity of the discharge hole 12, The inner wall surface of the nozzle 10 needs to be formed at different angles with respect to the axial direction. In this embodiment, the angle formed by the tip of the valve body 14 with respect to the axial direction The inner wall surface is formed smaller than the angle θ formed with respect to the axial direction, and in the valve closed state, the outer peripheral surface of the valve body 14 and the nozzle inner wall surface are substantially circular in a plane perpendicular to the nozzle axial direction. It comes into close contact with the contact line or contact surface. Further, by changing the angles of the outer peripheral surface of the valve body 14 and the inner wall surface of the nozzle 10 with respect to the axial direction, the distance from the discharge hole 12 to the contact surface as the valve opening / closing position can be adjusted. , Substantially in the same position.
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, it is possible to improve the sealing performance by forming either the nozzle 10 or the valve body 14 with a soft material such as resin or brass and forming the other with a hard metal material.

Here, an example in which the nozzle 10 having the valve function configured as described above is attached to the liquid dispensing apparatus will be described.
As shown in FIG. 2, the nozzle 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 is provided with a liquid inlet hole 22 introduced from a liquid storage container (not shown) through a flow path, and an outlet hole 24 leading to the nozzle 10. The space up to the discharge hole 12 constitutes the liquid storage unit 26.

The valve body 14 constituting the nozzle of the present invention has a tip portion located near the discharge hole 12 of the nozzle 10 and a rear end portion connected to a piston 30 of a cylinder 28 as will be described later. It can be moved forward and backward.
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 protrusion length of the discharge hole 12 from the seating position of the needle valve body 14 to the lower side is shortened as much as possible. Even after the discharge hole 12 is closed, it is preferable that the slight amount of liquid expected to remain in the discharge hole is 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, an air cylinder is used as a 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 is not limited thereto. 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.

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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nozzle 12 Discharge port 14 Needle-shaped valve body 16 Valve seat 20 Valve apparatus 22 Inlet hole 24 Outlet hole 26 Liquid storage part 28 Cylinder 30 Piston 32 Electromagnetic switching valve 34 Air source

Claims (4)

A nozzle for a liquid fixed quantity discharge device that discharges and stops discharge of pressurized liquid introduced into a liquid container,
A nozzle comprising a valve mechanism in a nozzle body that communicates with the liquid container. The nozzle according to claim 1, wherein the nozzle body has a liquid discharge hole, and the valve mechanism is provided in the vicinity of the discharge hole. The nozzle according to claim 1, wherein the valve mechanism includes a valve body movably provided in the nozzle body and a valve seat formed on an inner wall surface near the discharge hole. 4. The valve body according to claim 3, wherein a tip of the valve body is formed in a needle shape, and a peripheral surface of the tip is formed so as to be in close contact with the inner wall surface of the nozzle on a substantially circular contact line. Nozzle described in.

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