JP3656392B2 - Fluid discharge device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid discharge device, and more particularly to a device that does not cause dripping even when a fixed amount of adhesive or the like is discharged.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, as a device for discharging a fixed amount of adhesive or the like, there are, for example, a method in which pressure is fed by air pressure, a method in which a transport tube is squeezed out, a method in which a piston is pushed out, and a method in which a gear pump is pushed out. These devices are generally provided with a dripping prevention mechanism for retreating the fluid from the edge of the opening of the tip of the nozzle in order to prevent dripping after a predetermined amount of adhesive has been discharged.
For example, in the case of a system that pumps with air, dripping is prevented by sucking up the adhesive with a negative pressure in the flow path. In the case of a method of extruding with a piston, the piston is retracted to create a negative pressure in the flow path, and the adhesive is sucked up to prevent dripping.
[0003]
However, if the adhesive is largely retracted to completely prevent dripping, it is difficult to accurately discharge a predetermined amount of adhesive in the next step. On the other hand, if the amount of retraction of the adhesive is reduced in order to accurately discharge a predetermined amount of adhesive, dripping may not be prevented completely. For this reason, fine adjustment is difficult with the above-described discharge device, and there is a problem that a fluid discharge device that can completely prevent dripping cannot be obtained.
[0004]
An object of this invention is to provide the fluid discharge apparatus which can prevent dripping completely in view of the said problem.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the fluid discharge device according to the present invention is a fluid discharge device that closes the discharge port of the valve seat with a ball valve biased upstream of the flow path. A recess having an inner diameter on which an outer peripheral surface of the ball valve can slide and a depth dimension obtained by adding a suck-back area dimension to the radius of the ball valve As it is.
The ball valve may be slid in the recess based on the reciprocating movement of the plunger.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment according to the present invention will be described with reference to the accompanying drawings of FIGS.
That is, the fluid discharge device according to the present embodiment is used, for example, for filling an adhesive of a sealed relay, and is applied to discharge of a fixed amount of adhesive, and a valve seat block 20 at one end of the device main body 10. The coil block 30 is attached via A nozzle block 40 is attached to the tip of the coil block 30.
[0007]
A plunger 12 is inserted into a cylinder 11 provided in the apparatus main body 10 so as to be reciprocally movable, and an inlet 13 communicating with the cylinder 11 is provided on a side wall.
[0008]
The valve seat block 20 is provided with a recess 22 having an inner diameter through which the ball valve 21 can slide, and the recess 22 communicates with the cylinder 11 through a discharge port 23.
[0009]
The coil block 30 is provided with a through-hole 31 having a stepped cross section partially having an inner diameter larger than that of the recess 22, and a coil spring 32 for energizing the ball valve 21 upstream is housed therein. ing.
[0010]
The nozzle block 40 has four nozzles 41 arranged in parallel at the tip thereof, and each nozzle 41 communicates with the recess 22 through the through hole 31.
[0011]
Next, the operation of the fluid discharge apparatus having the above-described configuration will be described.
First, in the stationary state, the plunger 12 is at the highest position. Then, the ball valve 21 urged upstream by the spring force of the coil spring 32 is pressed into the recess 22 of the valve seat block 20 to close the discharge port 23, whereby the adhesive 50 in the apparatus main body 10. And the adhesive 50 in the coil block 30 are blocked. At this time, the adhesive 50 in the nozzle 41 is slightly retracted.
[0012]
When the plunger 12 is pushed down, pressure is transmitted to the adhesive 50 in the apparatus main body 10, and the ball valve 21 is pushed down against the spring force of the coil spring 32. For this reason, the adhesive 50 flows in from the gap between the inner surface of the through hole 31 in the coil block 30 and the surface of the ball valve 21, and the adhesive 50 in the nozzle block 40 is pushed out from the nozzle 41 (FIG. 2).
[0013]
When the plunger 12 is pulled up, the pressure in the cylinder 11 of the apparatus main body 10 decreases, so that the ball valve 21 is pushed up by the spring force of the coil spring 32. For this reason, the surface of the ball valve 21 comes into contact with the opening edge of the recess 22 and blocks the adhesive 50 in the coil block 30 and the adhesive 50 in the valve seat block 20 (FIG. 3).
[0014]
Further, by pulling up the plunger 12, the ball valve 21 is pushed upstream by the suck back region S shown in FIG. 3, so that the pressure in the coil block 30 decreases and the adhesive 50 in the nozzle block 40 is sucked up. . For this reason, the adhesive 50 in the nozzle 41 slightly recedes, and dripping can be reliably prevented.
[0015]
According to the present embodiment, the retraction amount of the adhesive 50 can be determined easily and surely only by determining the suck back region S of the ball valve 21, so that the fine adjustment as in the conventional example is not necessary, and the liquid Who can be surely prevented.
Further, since the ball valve 21 is in line contact at two locations in the recess 22 of the valve seat block 20, liquid leakage can be reliably prevented. In particular, there is an advantage that a fluid fixed quantity discharge device having a long life can be obtained because liquid leakage caused by wear due to long-term use can be surely prevented.
[0016]
In the above-described embodiment, the case where the adhesive is discharged from the four nozzles has been described. However, the present invention is not limited thereto, and the adhesive may be discharged from one nozzle.
Further, the applicable fluid discharge device is not limited to a method of pushing out by a plunger, and for example, a method of squeezing and feeding a conveyance tube or a method of pressure feeding by air pressure may be used.
[0017]
【The invention's effect】
As is apparent from the above description, according to the fluid discharge device of the present invention, after the ball valve blocks the fluid at one end, the ball valve is further pushed back only in the so-called suckback region. For this reason, the adhesive located downstream from the ball valve is pulled back, and dripping can be reliably prevented.
In particular, according to the fluid discharge device of the second aspect, since the ball valve is driven by the reciprocating movement of the plunger, the response characteristic is good, and there is an effect that the dripping can be more reliably prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a stationary state of a fluid discharge apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing the operation of the fluid discharge device according to FIG.
FIG. 3 is a cross-sectional view showing the fluid discharge device according to FIG. 1 in the middle of retraction.
FIG. 4 is a cross-sectional view showing the fluid discharge device according to FIG. 1 immediately after it is stationary.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Apparatus main body, 11 ... Cylinder, 20 ... Valve seat block, 21 ... Ball valve, 22 ... Recess, 23 ... Discharge port, 30 ... Coil block, 31 ... Through-hole, 32 ... Coil spring, 40 ... Nozzle block, 41 ... Nozzle, 50 ... Adhesive.

Claims (2)

In the fluid discharge device that closes the discharge port of the valve seat with a ball valve biased upstream of the flow path,
At the downstream opening edge of the discharge port of the valve seat, the ball valve has an inner diameter on which the outer peripheral surface of the ball valve can slide, and a depth dimension obtained by adding a suck back region dimension to the radius of the ball valve. A fluid discharge device characterized in that a recess is provided.   The fluid discharge device according to claim 1, wherein the ball valve is slid in the recess based on a reciprocating movement of a plunger.

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