JPH0511513B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a viscous liquid extrusion device. More particularly, the present invention relates to an apparatus for dispensing a relatively highly viscous liquid onto the surface of a workpiece.

[Prior Art] Conventionally, relatively high viscosity liquids such as various adhesives, greases, silicones, brazing pastes, resin liquids for molding and pouring, which have no self-flowing properties or have low self-flowing properties have been used. For this purpose, a viscous liquid storage container with a discharge port directly connected to a nozzle and a viscous liquid in the storage container are used. There are known devices equipped with a pneumatic device that presses the air. This device operates a pneumatic device to cause a viscous liquid in a storage container to flow out under pressure, and can be poured out from a nozzle and applied onto the surface of a workpiece.

[Problem that the invention seeks to solve]

However, if air bubbles are mixed into the viscous liquid in the storage container, the air bubbles will be pushed out of the nozzle while still being contained in the viscous liquid, causing an interruption in the pouring state, a so-called dry pouring phenomenon. It has the drawback of making the pouring incomplete. In addition, it has the following drawbacks, and even if it is poured continuously,
Even if it is poured in dots, the amount poured is not constant.
That is, when continuous dispensing is continued, the amount of liquid in the storage container changes, and accordingly, the higher the viscosity of the liquid, the more the resistance of the liquid changes.
On the other hand, since the pressure applied by the pneumatic device is constant,
The pouring amount changes depending on the resistance change of the liquid. In addition, when dispensing discontinuously, for example, in spots, the pneumatic device usually has a solenoid valve and a pressure regulator, and the solenoid valve switches between the pressure regulation output and the atmosphere, or the pressure regulator output and atmospheric pressure. Because it switches between the following pressures,
If the volume of air in the container increases as the amount of liquid in the storage container decreases, the time required for pressurization will change, and the amount dispensed will also change. Therefore, even if the amount to be dispensed is set by adjusting the air pressure, if the viscous liquid in the storage container decreases, the amount to be dispensed as set cannot be obtained.

The present invention has been made based on the above circumstances, and its purpose is to remove air bubbles mixed in the viscous liquid by taking advantage of the conventional device equipped with a pneumatic device that can pump viscous liquid. , can push viscous liquid without bubbles through the nozzle,
Moreover, even if the amount of viscous liquid in the storage container decreases, the present invention aims to provide a viscous liquid extrusion device that can obtain a stable extraction amount as set.

[Means for solving problems]

For this purpose, in the present invention, a viscous liquid is provided which is equipped with a nozzle, a storage container having an outlet through which the viscous liquid flows out toward the nozzle, and a pneumatic device that pressurizes the viscous liquid in the storage container. In the liquid extrusion device, a screw device consisting of a cylinder and a screw rod rotatably inserted into the cylinder is interposed between the nozzle and the storage container, and the nozzle is protruded from the liquid outlet side of the cylinder. death,
A supply hole for introducing the viscous liquid is provided on a side surface of the cylinder opposite to the liquid outlet side, and an outlet of the storage container is connected to the supply hole, and the liquid outlet side of the cylinder is connected to the supply hole. A bubble vent hole is provided on the opposite side surface at a position rearward from the supply hole.

〔Example〕

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

The viscous liquid extrusion device shown in FIG. 1 has a pressure regulator 1, a three-way switching solenoid valve 2, a storage container 3, a screw device 4, and a nozzle 5. The solenoid valve 2 and the pressure regulator 1 are connected to the hose 6 and the storage container 3
is combined with The pressure regulator 1 adjusts the air pressure of compressed air supplied from the air pressure source 7 to an appropriate air pressure. The solenoid valve 2 switches between the pressure regulator output and the atmosphere by electromagnetic action. 8 is a pressure meter. The storage container 3 is connected to a hose 6 on one side and is provided with an intake port 9, and the other side of the storage container 3 is provided with a discharge port 10. Furthermore, a pressure displacement plunger 11 is provided inside the storage container 3, and a viscous liquid 12 is stored between the pressure displacement plunger 11 and the discharge port 10. A screw device 4 is interposed between the discharge port 10 and the nozzle 5.

The screw device 4 is constructed by inserting a screw rod 14 connected to an electric motor 13 into a cylinder 15. The cylinder 15 has a nozzle 5 protruding from one end on the liquid outlet side.
A supply hole 16 for introducing the viscous liquid 12 is provided on the side surface opposite to the liquid outlet side, and the discharge port 10 of the storage container 3 is connected to the supply hole 16 . Reference numeral 17 indicates a motor cover tube coupled to the cylinder 15, 18 indicates a bubble vent hole, and 19 indicates a bearing. The air bubble vent hole 18 is located on the side surface of the cylinder 15 opposite to the liquid outlet side, and is located on the side surface of the cylinder 15 opposite to the liquid outlet side.
It is located further back.

Next, the effect will be explained.

The pressure regulator 1 is connected to the pneumatic source 7, and the solenoid valve 2
When the electric motor 13 is operated, the set output air pressure entering the storage container 3 causes the viscous liquid 12 to enter the cylinder 15 from the discharge port 10 under pressure. At this time, the viscous liquid 12 in the area surrounded by the inner wall of the cylinder 15 and the screw groove of the screw rod 14 is compressed as it goes from the supply hole 16 to the nozzle 5, and air bubbles in the viscous liquid 12 can be separated. The bubbles do not escape from the supply hole 16 filled with the viscous liquid 12, but escape from the bubble vent hole 18 provided separately from the supply hole 16, so that the viscous liquid 12 without air bubbles can be poured out from the nozzle 5. becomes. In addition, since the air bubble vent hole 18 is provided on the side surface of the cylinder 15 on the side opposite to the liquid outlet side and at a position rearward from the supply hole 16, the air bubble vent hole 18
The viscous liquid 12 is not forced out. Furthermore, the liquid resistance changes as the amount of liquid in the storage container 3 changes, and the air inflow volume in the container 3 increases, so that the amount of inflow per hour from the discharge port 10 into the cylinder 15 decreases. Even if there is a slight change, since the screw rod 14 is rotated by the electric motor 13 in the cylinder 15, the above-mentioned variation in the inflow amount is absorbed while being sent to the nozzle 5 by the screw rod 14. Therefore, the viscous liquid 12 without bubbles can be poured out from the nozzle 5, and the viscous liquid 12 can always be poured out from the nozzle 5 onto the surface of the workpiece as set.

Next, the control system for the solenoid valve and electric motor will be explained. As shown in the circuit configuration shown in FIG. 1, the solenoid valve 2 and the motor drive circuit 20 are connected to a power supply 22 via a power supply disconnection circuit 21. The variable resistor 23 is connected to the motor drive circuit 20 to appropriately adjust the rotational speed of the motor 13. 24 is a power on switch, 2
5 is a transformer, 26 is a rectifier circuit, 27 is a continuous dispensing switch, 28 is a discontinuous dispensing switch, T is a timer, t1 is a timer contact, 29 is a timer operation switch, R is a relay, and r1 to r3 are relays Each contact point is shown.

When the power-on switch 24 is closed, power from the power source 22 is constantly applied to the rectifier circuit 26. On the other hand, the solenoid valve 2, the motor drive circuit 2
Since power from the power supply 22 is applied to the power source 22 through the power supply disconnection circuit 21, the circuit 21 is always open. When the continuous dispensing switch 27 is closed, the relay R in the circuit 21 is energized and the relay contacts r1, r2, and r3 operate together, so that the solenoid valve 2 and the electric motor 13 start driving. The driving of the electromagnetic valve 2 and the electric motor 13 is stopped by opening the continuous dispensing switch 27 and releasing the excitation of the relay R.

The above is a case of continuous dispensing, but when dispensing is to be performed intermittently and discontinuously, the discontinuous dispensing switch 28 is used, and the power supply is disconnected each time this switch 28 is repeatedly opened and closed. Each relay contact in the circuit 21 is repeatedly connected and disconnected, and the solenoid valve 2 and the motor 13 are repeatedly driven and stopped. Further, when the tire operation switch 29 and the discontinuous dispensing switch 28 are closed, the timer T is activated, and dispensing corresponding to the timer time becomes possible.

In any of the above dispensing modes, the electric motor 13
When the drive of the solenoid valve 2 is stopped, the power to the solenoid valve 2 is also cut off, and even if the motor 13 is stopped, the pressure in the storage container 3 never increases, so the viscous liquid can be pushed out without dripping from the nozzle 5. can be stopped.

In the above example, when the relay contact r3 is provided and the power supply switch 24 is closed, the solenoid valve 2
is not activated, but relay contact r3
Alternatively, the solenoid valve 2 may be operated by closing the power supply switch 24 without providing the switch.

Next, the viscous liquid extrusion device shown in FIG. 2 will be explained. In this device, in addition to a liquid guide screw 14a, a screw rod 14 of a screw device 4 is provided with a backflow prevention screw 14b having a smaller pitch than the screw, two wedge-shaped protrusions 14c, and a flange 14d. First, this embodiment differs from the previous embodiment.

The groove width of the backflow prevention screw 14b is viscous liquid 1.
Although it varies depending on the type of 2, it is preferably in the range of 1 to 3 mm. A wedge-shaped projecting piece 14e is provided on the flange 14d, and the screw pitch of the liquid guiding screw 14a is gradually made smaller as it goes toward the nozzle 5 side. The wedge-shaped protruding piece 14e and the wedge-shaped protruding piece 14c are sequentially located on an extension line of the end of the backflow prevention screw 14b, and the wedge-shaped protruding piece 14
e and each tip of the wedge-shaped protruding piece 14c is formed to face the backflow prevention screw 14b. This screw rod 14 is inserted into the cylinder 15, and a backflow prevention screw 14b, a wedge-shaped projection piece 14c, and a flange 14d are inserted between the air bubble vent hole 18 and the supply hole 16.
is located. The flange 14d is the cylinder 15
It is rotatably fitted so as to have a ventilated gap 14f between the inner surface and the inner surface.

In this way, the liquid guide screw 14a is formed so that the screw pitch gradually becomes smaller as it goes toward the nozzle 5 side, so that the pressure increases on the nozzle side of the screw rod 14 to expel bubbles and improve discharge performance. It can be made into something. Moreover, the screw rod 14 is provided with a backflow prevention screw 14b having a smaller pitch than the liquid guiding screw 14a, and this backflow prevention screw 1
4b is located between the air bubble vent hole 18 and the supply hole 16, the air bubbles mixed in the viscous liquid 12 are pushed up by the rotation of the screw rod 14 and pass through the screw groove of the backflow prevention screw 14b. , this backflow prevention screw 14b
Because the screw pitch is small, the supply hole 17
Even if a part of the viscous liquid 12 introduced from the viscous liquid 12 tries to flow back to the rear end side opposite to the transfer direction of the screw rod 14 due to the pumping pressure, it is difficult to pass through the backflow prevention screw 14b due to the viscous resistance of the liquid itself.
Even if the viscous liquid 12 enters the backflow prevention screw 14b, the backflow prevention screw 14b will not rotate during rotation.
The shape of the screw forms a liquid scraping passage, and the scraped liquid is transferred through this passage and the liquid guiding screw 14a. Therefore, the viscous liquid 12 is prevented from flowing back toward the rear end of the screw rod 14. Further, a flange 14d is provided on the screw rod 14,
This flange 14d is connected to the air bubble vent hole 18 and the supply hole 1.
6, the viscous liquid 12
Even if the liquid should pass through the backflow prevention screw 14b, it will be completely blocked by the flange 14d, and the flange 14d is rotatably fitted to the inner surface of the cylinder 15 so as to have a gap 14f that allows ventilation. , the bubbles can be discharged from the bubble vent hole 18 through this gap 14f.

In order to prevent dripping from the nozzle 5 after completion of discharge, when the electric motor 13 is operated in reverse, a wedge-shaped protruding piece 14e is provided on the flange 14d,
In addition, the flange 14d and the backflow prevention screw 14
A wedge-shaped protruding piece 14c is provided between the wedge-shaped protruding piece 14e and the wedge-shaped protruding piece 14c. Projection piece 14c
Since each tip of the is installed facing the backflow prevention screw 14b, the viscous liquid 12 that has passed through the backflow prevention screw 14b is Wedge-shaped protruding piece 14e, wedge-shaped protruding piece 1
It collides with the inclined wall a of 4c and is pushed back in the direction of arrow A. Therefore, even if the screw rod 14 is reversed and the viscous liquid 12 is forcibly transferred, backflow of the viscous liquid can be prevented. Next, when the electric motor 13 is rotated normally again for dispensing, the viscous liquid 12 accumulated around the wedge-shaped projections 14e and 14c becomes wedge-like, as shown in FIG. Inclined wall b of the wedge-shaped protruding piece 14e and the wedge-shaped protruding piece 14c
The liquid is pushed in the direction of arrow B, and is transferred toward the nozzle through the path of the backflow prevention screw 14b and the liquid guide screw 14a.

In this way, the viscous liquid 12 without bubbles can be poured out from the nozzle 5 as described above, and the viscous liquid 12 can always be poured out from the nozzle 5 on the surface of the workpiece as set. Even if the gas flows backward, overflowing from the air bubble vent hole 18 can be prevented.

Note that a wedge-shaped projecting piece 14e is provided on the flange 14d.
However, if the wedge-shaped protruding piece 14e is provided as in the above embodiment, the reduction in liquid entrainment by the flange 14d can be avoided, and , when a plurality of wedge-shaped protruding pieces 14c are provided, the wedge-shaped protruding piece 1
Together with the installation of 4e, the flow path between the flange 14d and the backflow prevention screw 14b can be narrowed, making it even more difficult for viscous liquid to pass through.

Next, the control system for the solenoid valve and electric motor will be explained. As shown in the circuit configuration shown in FIG. 2, a transformer 34 and a solenoid valve 2 are connected to a power source 30 via a fuse 31, a power-on switch 32, and a power-on indicator light 33. A motor control circuit 36 including a rectifier circuit 35 and an automatic overload stop circuit is connected to the transformer 34 . The motor control circuit 36 includes a variable resistor 37 that adjusts the motor rotation speed, and a warning lamp 3.
8 and an alarm buzzer 39. moreover,
The motor control circuit 36 is connected to the forward/reverse rotary motor 13 via a forward/reverse switching circuit 40 . Specifically, the forward/reverse switching circuit 40 includes normally closed relay contacts r2-1, r2-3 for forward rotation, and normally open relay contacts r2-2, r2-4 for reverse rotation. The forward/reverse switching circuit 40 is connected to the motor control circuit 36 via a normally open timer contact r2-2 for connecting/disconnecting the output to the motor. Relay contacts r2-1, r2-2, r2-3, r2-4 are operated by relay R2, and timer contact t2-2 is operated by timer T2, but relay R2 is operated via normally closed timer contact t2-1. and is connected to timer T2. Then, timer T2 is connected to relay r, which will be described later.
Power supply 30 via the normally closed relay contact r1-1 of 1
It is connected to the.

On the other hand, on the rectifier circuit 35 side, a continuous dispensing switch 41 that determines the dispensing mode, an external input terminal 42, and a timer operation switch 43 are provided.
It is connected to the. The external input terminal 42 is connected to the timer contact t1-1 of the timer T1 and the relay R1, and the timer operation switch 45 is connected to the relay R1.
They are each connected to a rectifier circuit 35 via one normally closed relay contact r1-2 and a timer T1.

When the power-on switch 32 is turned on, power is applied to the relay contact r1-1, the timer contact t2-1, and the solenoid valve 2. When relay contact r1-1 is closed, timer T2 starts counting;
During this time, since relay R2 is energized, power of opposite polarity is applied to motor 13 through timer contact t2-2 and relay contacts r2-2 and r2-4. After a predetermined period of time has elapsed, timer T2 operates and timer contact t2-
1, t2-2 is open, the relay R2 is de-energized and the application of power to the forward/reverse switching circuit 40 is cut off. When the power supply switch 32 is turned on in this manner, the operation of the power supply valve 2 is started, and the electric motor 13 is reversely rotated for a predetermined period of time and then stopped.

When the continuous dispensing switch 41 is turned on, the relay R1 is excited and the relay contact r1-1 is opened, so the timer T2 and the relay R2 are not activated, and the output of the motor control circuit 36 is connected to the timer contact t2-1. 2,
Motor 1 via relay contacts r2-1, r2-3
3 is applied. In this way, the continuous pouring switch 4
1 is turned on, the electric motor 13 performs normal rotation drive.

The above is a case of continuous dispensing, but dispensing can be performed intermittently and discontinuously, or continuous dispensing can be performed only for a predetermined period of time. If dispensing is to be performed intermittently and discontinuously, for example, a foot switch (not shown) is connected to the external input terminal 42.
When the foot switch is repeatedly opened and closed, the electric motor 13 rotates in the normal direction each time. Further, when both the continuous dispensing switch 41 and the timer operation switch 43 are turned on, the electric motor 13 rotates in the normal direction for a time determined by the timer T1.

In any of the above dispensing modes, relay R1
When the excitation is released, the relay contact r1-1 is closed, so the timer T2 and the relay R2 operate in the same way as described above, and the motor 13 rotates in reverse for a predetermined period of time, and then stops.

〔Effect of the invention〕

As described above, the present invention is capable of removing air bubbles mixed in the viscous liquid when pouring the viscous liquid onto the surface of the workpiece, and pouring out the viscous liquid without air bubbles. Even if the viscous liquid decreases,
This is useful because it provides a viscous liquid extrusion device that can provide a stable discharge amount as set.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the viscous liquid extrusion device of the present invention,
FIG. 2 is an explanatory view of another example of the device of the present invention, and FIG. 3 is an explanatory view of the device shown in FIG. 2, with the flange and wedge-shaped protrusions expanded on a plane. 1 is a pressure regulator, 2 is a three-way switching solenoid valve, 3
is a storage container, 4 is a screw device, 5 is a nozzle,
6 is a hose, 10 is a discharge port, 12 is a viscous liquid, 1
4 is a screw rod, 15 is a cylinder, 16 is a supply hole, and 18 is a bubble vent hole.

Claims (1)

[Claims] 1. A viscous liquid extrusion device comprising a nozzle, a storage container having a discharge port through which the viscous liquid flows toward the nozzle, and a pneumatic device that pressurizes the viscous liquid in the storage container. A screw device consisting of a cylinder and a screw rod rotatably inserted into the cylinder is interposed between the nozzle and the storage container, and the nozzle is protruded from the liquid outlet side of the cylinder, A supply hole for introducing the viscous liquid is provided on a side surface of the cylinder opposite to the liquid outlet side, and a discharge port of the storage container is connected to the supply hole, and the liquid outlet side of the cylinder is connected to the supply hole for introducing the viscous liquid. A viscous liquid extrusion device comprising a bubble vent hole provided on the opposite side surface at a position rearward of the supply hole.