JPS63236559A - Liquid emitting apparatus - Google Patents

Abstract

PURPOSE:To stably emit a liquid with high accuracy while preventing liquid leakage and a back flow and facilitating an adjustment, by successively arranging a pump, a close vale, a check value and a suck-back valve in series in a direction toward a liquid emitting nozzle. CONSTITUTION:When the solenoid valve 110 connected to an air pressure source is operated, a pump 102 becomes an emitting state and a sucked treatment liquid 109 is extruded to be emitted from the leading end of a nozzle 101 through a close valve 103, a check valve 104 and a suck-back valve 105. When the solenoid valve 110 is stopped after the emission is finished, the pump 102 becomes a suction state and the close valve 103 is closed and the suck-back valve 105 draws back the treatment liquid 109 in the nozzle. At this time, speed controllers 111, 113 are adjusted so as to previously close the close valve 103 within the time from the start of the sucking of the treatment liquid due to the pump 102 to the finish thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Application Field) The present invention relates to a highly accurate liquid ejection device used in the production of semiconductors, pharmaceuticals, foodstuffs, and the like.

(Prior Art) Liquid ejecting apparatuses as shown in FIGS. 2 to 5 are generally used in processes that require precision in the amount of liquid to be ejected, such as semiconductor manufacturing processes.

In FIG. 2, the solenoid valve 1 is operated and the pump 3 is brought into a suction state via the speed controller 2.

At this time, the close valve 4 is closed, so the pump 3
sucks the processing liquid 7 contained in the container 6 through the check valve 5.

Next, when the operation of the solenoid valve 1 is stopped, the pump 3 enters a discharge state via the speed controller 8, and the processing liquid 7 is discharged from the tip of the nozzle 10 via the close valve 4 and the suckback valve 9. When the discharge is finished, the solenoid valve 1 is operated to put the pump 3 into a suction state, and the suck bag valve 9 pulls back the processing liquid 7 in the nozzle 10 toward the Sarapack valve 9.

On the other hand, in FIG. 4, the processing liquid 47 contained in the container 46 is suctioned by the pump 43 via the check valve 45. Next, when the pump 43 is brought into the discharge state, the liquid is suctioned into the pump 43. The processing liquid 47 is discharged from the tip of the nozzle 50 via the check valve 44 and the suckback valve 49. Then, when the ejection is finished, the nozzle 50
The processing liquid 47 inside is pulled back.

(Problems to be Solved by the Invention) However, the above-mentioned device has the following problems.

First, in the apparatus shown in FIG. 2, when the close valve 4 performs a closing operation, the discharge amount is stable enough to prevent the pumping action of discharging the processing liquid 7 in the close valve 4 outward. do not.

FIG. 3 shows the internal structure of the close valve 4.
The cylinder 11 presses the valve 12 against the valve seat 13 to make it liquid-tight. Generally, the valve 12 is fixed to the diaphragm 14, etc., so when the valve 12 moves downward and closes, the diaphragm 14 deforms toward the valve seat 13.

Therefore, the volume of the liquid chamber 15 decreases,
Processing liquid is discharged outside the close valve 4.

In order to reduce the influence of this discharge, the operation timings of the pump 3 and the close valve 4 are adjusted so that the pumping action of the close valve 4 is absorbed by the suction force of the pump 3. However, generally pump 3, close valve 4
Since both are driven by air pressure, it is extremely difficult to keep their timing stable at all times.

For example, if the closing speed of the close valve 4 is faster than the suction speed of the pump 3, the processing liquid 7 is placed on the nozzle 10 side.
It pushes out.

On the other hand, if it is too late, a large amount of the processing liquid 7 will be absorbed into the pump 3 from the nozzle 10 side.

Next, in the apparatus shown in FIG. 4, the stability and reliability of the check valves 44 and 45 are problematic, and the processing liquid 47 tends to drip from the nozzle 50 and backflow into the container 46.

The check valves 44 and 45 perform a check function when pressure is applied to the valve, but when no pressure is applied, for example, the pump 43
When the system is at rest, liquid leakage and backflow may occur.

That is, as shown in FIG. 5, the check valves 44 and 45 become liquid-tight when the ball 51 contacts the seat 52, but when no pressure is applied, the check valves 44 and 45 become liquid-tight only by the weight of the ball 51.

Therefore, the ball 51. Even if the seat 52 has very small scratches, surface roughness, etc., liquid leakage will occur. For example, if the nozzle 50 is located higher than the container 46, the processing liquid 47 will flow back toward the container 46 if left for a long time, and if the nozzle 50 is located lower than the container 46, the nozzle 50 will flow back toward the container 46.
The processing liquid 47 leaks from the tip.

Here, the check valve 44.45 is made more reliable, for example, the check valve 44.45 that forcibly presses the ball 51 with a spring or the like, or the number of check valves 44.45 used is increased. Things, etc. are also used. However, in this case, a strong force is required to open the reversal valves 44, 45, which increases flow path resistance, making it impossible to handle high viscosity liquids.

In addition, if the check valves 44, 45 are stacked in series or if a suppressing material such as a spring is placed inside the check valves 44, 45, air bubbles are likely to accumulate inside, making the discharge amount unstable. .

The present invention has been made in response to the above-mentioned conventional circumstances, and aims to provide a liquid ejection device that is easy to adjust and has high ejection accuracy.

[Structure of the invention]

(Means for Solving the Problems) That is, the present invention includes a pump that sucks and discharges the liquid to be discharged, a first valve that controls intermittently the flow of the liquid to be discharged, and a first valve that allows the liquid to be discharged to pass in only one direction. A check valve, a second valve that pulls back the liquid to be discharged in a direction opposite to the discharge direction at the end of discharge, and the pump and the first
The valve is characterized in that the valve is provided in this order, the check valve, and the second valve.

(Function) In the liquid discharge device of the present invention, the pump, the first valve, the check valve, and the second valve are arranged and connected in this order in the liquid discharge direction, and when the pump suctions, the The liquid on the second valve side does not flow backward, and the liquid can be prevented from flowing inside the device when the pump is stopped.

(Example) Hereinafter, an example of the liquid ejection device for use in the present invention will be described with reference to one drawing.

In order toward the liquid discharge nozzle 101, a pump 102,
First valve, for example, close valve 103, check valve 10
4, a second valve such as the suckback valve 105;
Nozzles 101 are arranged and connected in series.

A suction port 106 of the pump 102 is connected to a check valve 107 via piping, and is configured to be able to suction the processing liquid 109 contained in a container 108 via the check valve 107.

The pump 102 also includes a speed controller 111 connected to the solenoid valve 110 and used to adjust the suction speed of the pump 102 . A suction and discharge operation is performed by a speed controller 112 for adjusting the discharge speed.

Next, the close valve 103 is equipped with a speed controller 113 that adjusts the closing speed of the nozzle 1 after the discharge is completed.
Suckback valve 1 that pulls back the processing liquid 109 in 01
05 is a speed controller 11 that adjusts the suction speed.
4 are connected.

Both speed controllers 113 and 114 are connected to the same solenoid valve 110 output as the speed controller 111 of the pump 102.

Next, the operation will be explained.

First, the solenoid valve 110 connected to a pneumatic source (not shown) is operated to set the pump 102 to the discharge state, which pushes out the processing liquid 109 that has been sucked into the pump 102 and closes the valve 103, the check valve 104, and the sack. It passes through the back valve 105 and is discharged from the tip of the nozzle 101.

After discharging, when the solenoid valve 110 stops operating, the pump 102 enters the suction state, and the close valve 10
3 is closed, and the suck back valve 105 sucks the processing liquid inside the nozzle 101 and pulls it back.

At this time, adjust the speed controllers 111 and 113 so that the close valve 103 closes first within the time period from when the pump 102 starts suctioning the processing liquid 109 through the check valve 107 to when it ends. .

Then, since the pump 102 is in the suction state, the check valve 104 acts, and there is no backflow of liquid from the suckback valve 105 side, and the pump 102 completely absorbs the extruded liquid due to the pumping action when the close valve 103 closes. Therefore, the processing liquid 109 is not pushed out from the nozzle 101.

Furthermore, even if the device is left unattended with the pump 102 in a paused state,
Since there is a close valve 103 in addition to the check valves 104 and 107, the flow path is completely closed, so that the processing liquid 1
09 flows back toward the container 108.

There is no leakage from the nozzle 101.

Note that, as an example of an adjustment method for this device, the following adjustment is performed.

First, the speed controller 112 of the pump 102 adjusts the discharge speed to an appropriate value.
While gradually loosening the speed controller 113 of 03 from the throttled state, adjust the close valve 103 so that it closes from the start of suction to the end of suction by the pump 102. This adjustment can be easily performed because the suction time of the pump 102 is long.

Thereafter, the suction amount of the suckback valve 105 is adjusted using the adjustment screw 115, and the suction speed is adjusted using the speed controller 114.

Note that if the check valve 104 and the suckback valve 105 are arranged oppositely, the processing liquid 10 in the nozzle 101 at the end of liquid discharge.
Cannot perform the suckback motion to pull back the 9.

Therefore, as in this embodiment, the check valve 104 is disposed between the close valve 103 and the suckback valve 105.

〔Effect of the invention〕

As described above, according to the present invention, the liquid to be ejected does not flow backward or leak, so that ejection accuracy is high, adjustment is easy, and stable liquid ejection can be performed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the liquid ejection device of the present invention;
FIGS. 2, 3, and 3 are block diagrams showing one conventional example, and FIGS. 4, 5, and 5 are block diagrams showing other conventional examples. 102...Pump, 103...Close valve, 104...Check valve, 105...Suckback valve. 107...Check valve, 111, 113...Speed controller. Figure 3 Figure 5

Claims (1)

[Claims] A pump that sucks and discharges the liquid to be discharged; a first valve that intermittently controls the flow of the liquid to be discharged; a check valve that allows the liquid to pass in only one direction; The liquid discharger is equipped with a second valve that pulls back in the opposite direction, and the pump, the first valve, the check valve, and the second valve are provided in this order toward the flow path of the discharged liquid. Device.