JPH1024263A - Fixed volume discharging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity by shortening the fall time of the pressure in a syringe after discharging the fixed volume of liquid from this syringe. SOLUTION: Pressurized air is supplied via a solenoid-operated selector valve 6 from an air supplying source 8 to the syringe 2 packed with the liquid 1 and the fixed volume of the liquid is discharged from the syringe 2. A quick exhaust valve 4 is arranged near the syringe 2. This quick exhaust valve 4 is operated by the pressurized air in the syringe 2 to discharge the pressurized air in the syringe 2 at the ending time of the supply of the pressurized air. The route for discharging the pressurized air from the syringe 2 is made shorter than heretofore, by which the resistance of the discharge is lowered and the fall time is shortened. In addition, the pressure in the syringe 2 is instantaneously released at the end of the discharge and, therefore, the liquid droop from the syringe 2 by the residual pressure is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metering device, and more particularly to a syringe filled with a viscous fluid such as an adhesive, which is supplied with pressurized air from an air supply source via an electromagnetic switching valve for a predetermined period of time. The present invention also relates to a fixed-rate discharge device for discharging a fixed amount of fluid.

[0002]

2. Description of the Related Art As a device of this type, there is known a constant-rate discharging device used for discharging a constant amount of an adhesive in an adhesive applying device for a chip mounter, for example. In the conventional configuration of this type of device, an electromagnetic switching valve is provided in the middle of a pipe line for supplying pressurized air from an air supply source to the syringe, and pressurized air is supplied to the syringe via the electromagnetic switching valve. And
By controlling the supply time of the pressurized air, a fixed amount discharge is performed.

[0003] That is, at the time of discharge, when the electromagnetic switching valve is turned on by a control signal, the port on the syringe side of the electromagnetic switching valve communicates with the port on the air supply source side, and pressurized air is supplied to the syringe. At time T1 in FIG. 6, the pressure P of the air in the syringe rises, and the liquid is discharged from the syringe. Then, when the electromagnetic switching valve is turned off,
The syringe side port of the electromagnetic switching valve is switched so as to communicate with the port communicating with the atmosphere, and the pressurized air on the syringe side is exhausted into the atmosphere, and the pressure P in the syringe falls at time T2 in FIG. , The discharge ends. The discharge amount is controlled by controlling the on-time of the electromagnetic switching valve, which is the rise time T1.

[0004]

For example, when a fixed amount of adhesive is discharged in a chip mount adhesive applying apparatus, the productivity of the apparatus using the above described fixed amount discharging apparatus is as follows.
Rise time T1 + of pressure P in the syringe shown in FIG.
It depends on the fall time T2, and shortening this time T1 + T2 leads to an improvement in productivity and is demanded by the market.

Attention is paid to the fall time T2. In the above-described conventional configuration, when the pressurized air is exhausted by turning off the electromagnetic switching valve, the pressurized air in the syringe is discharged from the syringe,
The air is exhausted to the atmosphere through the piping between the electromagnetic switching valves, the electromagnetic switching valve, and the piping connected to the port of the electromagnetic switching valve that communicates with the atmosphere, if necessary. There was a limit in shortening the fall time T2.

Further, since it takes time until the pressure is completely released due to the above-mentioned resistance, liquid dripping from the syringe is apt to occur due to residual pressure. To prevent this, a mechanism for applying a negative pressure to the syringe is added. Therefore, there is a problem that the cost is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a quantitative discharge device which has a simple configuration and can reduce the fall time of the pressure in the syringe at the end of discharge.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an object of the present invention is to supply a pressurized air from an air supply source to a liquid-filled syringe through an electromagnetic switching valve to discharge a fixed amount of the liquid from the syringe. In the constant discharge device, a quick exhaust valve is disposed between the electromagnetic switching valve and the syringe, and when the supply of the pressurized air is completed, the quick exhaust valve is operated by the pressurized air in the syringe to exhaust the pressurized air in the syringe. The problem is solved by a quantitative discharge device characterized in that:

According to such a configuration, the resistance to the exhaust is reduced, and the exhaust from the syringe is rapidly performed at the end of the supply of the pressurized air, so that the fall time of the pressure in the syringe can be reduced. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows one embodiment of a fixed-rate discharge device according to the present invention.
An embodiment is illustrated.

In FIG. 1, reference numeral 2 denotes a syringe having a discharge port for discharging a liquid at its tip, and the syringe 2 is filled with a liquid 1 such as an adhesive. The syringe 2 is connected to a quick exhaust valve 4 via a pipe 3.

The quick exhaust valve 4 is disposed near the syringe, has a large exhaust passage area compared to the effective sectional area of the inlet, and has three ports A, B, and C as shown in FIG. A conical shuttle valve 42 is provided in the valve chamber 41 to which each port communicates. The shuttle valve 42 moves in a linear direction indicated by an arrow according to the relationship of the air pressure governing between the ports. Valve chamber 41
The inner surface on the port A side is formed in a conical curved surface corresponding to the shuttle valve 42, and a circular pipe 43 having a smaller diameter than the shuttle valve 42 protrudes from the port C side. Port B
Communicates with the side of the valve chamber 42.

With respect to the port B of the quick exhaust valve 4,
As shown in FIG. 1, a pipe 3 connected to the syringe 2 is connected. The port C of the quick exhaust valve 4 communicates with the atmosphere, and the port A is connected to an electromagnetic switching valve 6 via a pipe 5.

The electromagnetic switching valve 6 also has three ports A, B and C. The port A is connected to an air supply source 8 for supplying pressurized air via a pipe 7, and the port B is connected to a pipe 5 , The quick exhaust valve 4 is connected, and the port C communicates with the atmosphere. The electromagnetic switching valve 6 is turned on and off by a control signal from a control unit 9 composed of a microcomputer or the like to switch the communication state between the ports. The communication state between the ports A and B is in the on state, and the port is in the off state. B and C communicate with each other.

The control unit 9 includes a setting input unit 10 for setting a discharge condition such as a discharge amount using a keyboard, a switch, or the like.
And a display unit 11 for displaying data of the ejection condition set by the input. The control unit 9
The on-time of the electromagnetic switching valve 6 is determined based on the discharge condition data input from the setting input unit 10, and the electromagnetic switching valve is driven to perform the discharging operation. Further, the control unit 9 controls the air supply source 8 to maintain the pressure of the pressurized air supplied from the air supply source 8 at a constant pressure.

Next, the operation of the apparatus configured as described above will be described.

When an ejection signal instructing ejection of the liquid 1 is input from the host system (not shown) to the control unit 9, the control unit 9 determines the ejection signal based on ejection conditions set in advance by input from the setting input unit 10. The electromagnetic switching valve 6 is turned on for a predetermined time.

As a result, the electromagnetic switching valve 6 is connected to the ports A and B
The air is switched to communicate with each other, and pressurized air from the air supply source 8 is supplied to the port A of the quick exhaust valve 4 via the pipe 7, the electromagnetic switching valve 6, and the pipe 5. Then, the shuttle valve 42 is pushed by the pressure of the pressurized air and moves toward the port C as shown in FIG. This allows
The passage to port C is closed and the shuttle valve 4
A gap between the blade portion 42a at the end of port 2 and the port B is opened to allow communication between the ports A and B. Pressurized air flows from the port A to the port B as shown by an arrow, and the syringe 2 Supplied to Thereby, the pressure P of the air in the syringe 2 rises as shown at time T1 in FIG. 4, and the liquid is discharged from the syringe 2.

Subsequently, when the electromagnetic switching valve 6 is turned off after the elapse of the predetermined time, the ports B,
C communicates with each other, shutting off the ports A and B, terminating the supply of pressurized air, and shutting off the pressure from the port A in the quick exhaust valve 4. As a result, the pressure of the pressurized air previously supplied to the syringe 2 and the pipe 3 causes
As shown in (b), the shuttle valve 42 moves to the port A side to close the port A, the ports B and C communicate with each other, and
By increasing the cross-sectional area of the hole of the syringe 2,
A large amount of pressurized air in the pipe 3 flows from the port B to the port C in a short time as shown by an arrow, and is discharged into the atmosphere. As a result, the pressure P in the syringe 2 falls rapidly as shown at time T2 'in FIG. 4, and the discharge of the liquid from the syringe 2 ends.

Here, since the path of the exhaust gas for lowering the pressure P in the syringe 2 is shortened, the resistance to the exhaust gas is significantly reduced, and the fall time T2 'of the pressure P is much longer than the conventional fall time T2. Be shortened.

As described above, the fall time of the pressure in the syringe at the end of the discharge can be greatly reduced, so that the productivity of the apparatus using the constant discharge apparatus can be improved. In addition, since the pressure in the syringe can be released instantaneously at the end of discharge, liquid dripping from the syringe due to residual pressure can be prevented, and a mechanism for preventing the dripping is not required, thereby reducing the cost of the apparatus.

The effect of the rapid exhaust described above can be further enhanced by generating a negative pressure at the exhaust port C of the rapid exhaust valve. This example is illustrated in FIG.

In the configuration shown in FIG. 5, the exhaust port C of the quick exhaust valve 4 is connected to the air suction source 15 for generating a predetermined negative pressure via the electromagnetic switching valve 13. The electromagnetic switching valve 13 has a port A connected to an exhaust port C of the quick exhaust valve 4 via a pipe 12, a port B connected to an air suction source 15 via a pipe 14, and a port C connected to the atmosphere. ing. The electromagnetic switching valve 13 communicates between the ports A and B in the on state, and communicates between the ports B and C in the off state. The control unit 9 controls the electromagnetic switching valve 13 and the air suction source 15.

In such a configuration, the control unit 9 turns on the electromagnetic switching valve 6 for a predetermined time to perform a fixed amount discharge, then turns off the electromagnetic switching valve 6, and immediately thereafter, turns on the electromagnetic switching valve 13 for a predetermined time. turn on. When the electromagnetic switching valve 6 is turned off, the pressurized air in the syringe is rapidly exhausted through the exhaust port C as shown in FIG. At this time, when the electromagnetic switching valve 13 is turned on for a predetermined time, the negative pressure generated by the air suction source 15 acts on the port C of the quick exhaust valve 4 for a predetermined time, so that the pressurized air in the syringe 2 and the pipe 3 is discharged. The air is exhausted from the port C more rapidly than in the first configuration.
In this manner, the fall time of the pressure in the syringe 2 at the end of the discharge can be further reduced.

[0026]

As is apparent from the above description, according to the present invention, the quick exhaust valve is disposed near the syringe, and when the supply of the pressurized air is completed, the quick exhaust valve is operated by the pressurized air in the syringe. Since the pressurized air in the syringe is exhausted, the path for discharging the pressurized air is shortened, so that the syringe is quickly exhausted when the supply of the pressurized air is completed, and the pressure in the syringe is reduced. Falling time can be shortened. Further, since the pressure in the syringe can be released instantaneously at the end of the discharge, liquid dripping from the syringe due to residual pressure can be prevented, and a mechanism for preventing the dripping is not required, and the cost of the apparatus can be reduced. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a fixed-quantity ejection device according to the present invention.

FIG. 2 is a sectional view showing the structure of the quick exhaust valve of FIG.

FIG. 3 is a cross-sectional view showing the operation of a quick exhaust valve at the time of discharge and at the end of discharge.

FIG. 4 is a graph showing a change over time of a pressure in a syringe during a discharging operation.

FIG. 5 is a block diagram showing a configuration of another embodiment of the present invention.

FIG. 6 is a graph showing a time-dependent change in pressure in a syringe during a discharging operation of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid 2 Syringe 3,5,7,12,14 Piping 4 Rapid exhaust valve 6,13 Solenoid switching valve 8 Air supply source 9 Control part 10 Setting input part 11 Display part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Eiji Fukui, inventor Eiji Fukui 8-2-1 Kokuryo-cho, Chofu-shi, Tokyo

Claims (2)

[Claims] 1. A fixed-rate discharge device for supplying pressurized air from an air supply source to a liquid-filled syringe through an electromagnetic switching valve to discharge a fixed amount of liquid from the syringe. A fixed-quantity discharge device, comprising an exhaust valve, wherein at the end of the supply of pressurized air, the rapid exhaust valve is operated by the pressurized air in the syringe to exhaust the pressurized air in the syringe. 2. The fixed-rate discharge device according to claim 1, wherein a predetermined negative pressure is generated in an exhaust port of the rapid exhaust valve when the supply of the pressurized air is completed.