JPS6146184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a coating device that uses a pneumatic pump to continuously coat a medium-to-high viscosity liquid such as an adhesive or a sealant. To provide a coating device capable of forming a uniform coating layer of a medium-high viscosity liquid without causing any effects of pulsating flow generated when pumping the liquid and the initial jet at the start of discharge during coating. The purpose is

Conventionally, devices that automatically apply medium-high viscosity liquids,
In particular, as line drawing and coating devices, devices with a configuration in which a discharge gun is directly connected to a pneumatic pump are often used. Not only does the deposited layer not be uniform, but when discharging is interrupted and discharge is restarted, an initial injection occurs due to the pump stop pressure, which also has the disadvantage that the deposited layer is not uniform.

According to the present invention, by having the structure described in the claims, it is possible to form a uniform coating layer without having the above-mentioned drawbacks while using a pneumatic pump.

The configuration of the illustrated example will be explained below.

FIG. 1 is a circuit diagram showing the configuration of the apparatus of the present invention, in which pressurized air supplied from a pressurized air supply source A is used as a drive source to drive various members described below.

In the illustrated example, there are two pneumatic pumps P ₁ and P ₂
are installed in parallel, and the pneumatic pump _P2 system is kept as a backup.

Pipe lines 3 and 4 communicating with the discharge ports 1 and 2 of the pneumatic pumps P ₁ and P ₂ are connected to a first two-way valve, respectively.
It communicates with the pump chambers of secondary reciprocating pumps 7, 8, which are plunger pumps, through switching valves 5, 6.

Discharge ports 9, 10 of the above-mentioned secondary reciprocating pumps 7, 8
Pipe lines 11 and 12 communicate with the discharge gun 1 through second switching valves 13 and 14, which are two-way valves, respectively.
5, 16, and check valves 77, 78 are inserted into the pipes 11, 12.

Regulators R ₁ and R ₂ are inserted into the drive circuits of the aforementioned pneumatic pumps P ₁ and P ₂ , and each pump P ₁ and P ₂ is driven at a regulated pressure.

Furthermore, manual valves 17 and 18 are inserted into the conduits 3 and 4, so that the conduits to be used can be switched.

The first switching valves 5 and 6, which are two-way valves, are as follows:
It is configured to be switched by solenoid valves SOL ₁ and SOL ₂ .

The drive circuit of the secondary reciprocating pumps 7 and 8, which are plunger pumps, includes regulators R ₃ and
R ₄ and solenoid valves SOL ₃ and SOL ₄ are inserted, whereby the secondary reciprocating pumps 7 and 8 are switched between performing the discharge stroke at a predetermined regulated pressure and bleeding air during the filling stroke. It will be done.

The aforementioned secondary reciprocating pumps 7, 8 are equipped with limit switches LS ₁ , LS ₂ , and these limit switches cause the aforementioned solenoid valves SOL ₁ and SOL ₂ to switch over the first switching valves 5 and 6 as described later. Switch to closed position.

The above-mentioned second switching valve 13 and discharge gun 15 set,
And the set of the second switching valve 14 and the discharge gun 16 is
Each drive circuit is operated by a single drive circuit, and each drive circuit has a solenoid valve.
SOL ₅ , regulator R ₅ , rapid exhaust valve 19, and solenoid valve SOL ₆ , regulator
R ₆ , a quick exhaust valve 20 is inserted, and in each of the second switching valve 13 and discharge gun 15 set and the second switching valve 14 and discharge gun 16 set, the opening of the second switching valve is inserted. It is configured such that the operation, the discharge operation of the discharge gun, the closing operation of the second switching valve at a predetermined regulated pressure, and the discharge closing operation of the discharge gun are performed simultaneously. Quick exhaust valve 1 mentioned above
9 and 20, the opening operation of the second switching valve and the discharge operation of the discharge gun are performed quickly and smoothly.

Further, the discharge of the secondary reciprocating pumps 7 and 8 is controlled by the combination of the second switching valve 13 and the discharge gun 15 and the second
This is performed when the pair of switching valve 14 and discharge gun 16 respectively occupy the open position, and at that time, each drive is controlled by a control device (not shown) so that the first switching valves 5 and 6 are in the closed position. The circuit operation timing is set.

Furthermore, the discharge amount of the secondary reciprocating pumps 7 and 8 at one time is larger than the total discharge amount during one discharge operation of the discharge gun, and the discharge start of the secondary reciprocating pumps 7 and 8 is made at the time of the second discharge operation. Switching valves 13, 14 and discharge guns 15, 1
The secondary reciprocating pumps 7 and 8 are configured to discharge only when the secondary reciprocating pumps 7 and 6 are open, and when each pair of the second switching valves 13, 14 and the discharge guns 15, 16 are in the closed position. The operation timing of each drive circuit is set by a control device (not shown) so that the timing is before the end of the discharge stroke.

Further, when each pair of the second switching valves 13, 14 and the discharge guns 15, 16 is in the closed position, the first switching valves 5, 6 are in the open position, and the secondary reciprocating pump 7,
The operation timing of each drive circuit is set by a control device (not shown) so that the fuel cell 8 enters the filling process.

The above-mentioned first switching valves 5 and 6 are switched to the closed position before the pump chambers of the secondary reciprocating pumps 7 and 8 are completely filled by the operation of the limit switches LS ₁ and LS ₂ described above.

Secondary reciprocating pump 7 in the configuration described above,
An example of a specific configuration of No. 8 is shown in FIG.

FIG. 2 shows the secondary reciprocating pump 7,
A distance 22 and a joint 23 connected to the first switching valve 5 side are fixed to the pump body 21. A cylinder base 24 is formed in the aforementioned destance 22, and a cylinder 26 and a cylinder head 27 are screwed together by a stay bolt 25.

A piston rod 29 of a piston 28 housed in the cylinder 26 extends through the cylinder base 24 toward the distance 22, and a pump rod 30 is screwed and fixed to the extending end. A spring 31 is interposed in this threaded portion to prevent the threaded portion from loosening.

The tip 32 of the aforementioned pump rod 30 passes through a metal seal 33 and a packing gland 34 built into the pump body 21, and a restraining plate 35, and faces into the pump chamber 36.
As the tip 32 moves forward and backward, the tip 32 reaches a position where it slightly protrudes into the pump chamber 36 as shown in FIG. Move back and forth between locations.

A limit switch dog 37 is fixed to the piston 28 in a direction opposite to the piston rod 29, and the dog 37 extends outwardly through the cylinder head 27 and is attached to a bracket 38 fixed to the cylinder head 27. It is configured to actuate a supported limit switch LS ₁ .
The point at which the aforementioned limit switch dog 37 operates the limit switch LS ₁ is when the pump rod 30
at a point slightly before the tip 32 assumes the final retracted position within the pump chamber 36.

In FIG. 2, reference numeral 39 is an air inlet for introducing pressurized air from the regulator R ₃ into the piston front chamber 40 by the solenoid valve SOL ₃ , and reference numeral 41 is a vent port for removing air from the piston rear chamber 42.
3 is an oil bath, which is an oil reservoir for improving sealing performance.

In the above-described configuration, when the pump rod 30, the piston rod 29, and the piston ₂₈ move backward to the positions shown in FIG. When the chamber 36 is pressurized and filled, hydraulic pressure is applied to the end face of the end 32 of the pump rod 30.

In the above configuration, the amount of liquid discharged from the secondary reciprocating pump 7 by one extrusion operation of the pump rod 30 is adjusted so that it is larger than the total amount of liquid discharged by one discharge operation of the discharge gun 15. has been done. The secondary reciprocating pump 8 also has exactly the same configuration as described above.

Further, one example of a specific configuration of the discharge guns 15 and 16 is shown in FIG.

FIG. 3 shows the discharge gun 15, and a discharge nozzle 46 is fixed to the gun body 44 via a connection 45.
Liquid passages 47 and 48 communicating with the gun body 44 and the connection 45 are drilled through the gun body 44 and the connection 45, and the gun body 4
4 is provided with a liquid inlet 50 that communicates with a conduit 49 extending from the second switching valve 13 and the liquid path 47, and a valve seat 51 is formed at the end of the liquid path of the connection 45.

A distance 52 is fixed to the above-mentioned gun body 44, and a cap 54 is screwed to a cylinder portion 53 at the end of the distance 52 to form a cylinder chamber, in which a piston 56 is housed.

As shown in FIG. 1, the air inlet 58 of the piston upper chamber 57 is connected to the conduit 5 which runs from the solenoid valve SOL ₅ through the regulator R ₅ and the quick exhaust valve 19.
9 is in communication with the air inlet 61 of the piston lower chamber 60.
is connected to another conduit 62 extending from the solenoid valve SOL ₅ .

A piston rod 63 of the piston 56 extends into the distance 52, and a valve rod 67 integrally connected to the end thereof by a coupling structure consisting of a collar 64, a nut 65, and a cap nut 66 is connected to the gun body 44.
The ball valve 70 is fixed to the end of the liquid passage 48 of the connection 45 through the seal retainer 68 and the clamp 69, and extends to the liquid passage end of the liquid passage 48 of the connection 45, so that the ball valve 70 can come into contact with the valve seat 51 at the end of the liquid passage. It is composed of

The above-mentioned contact and separation of the ball valve 70 from the valve seat 51, that is, the communication and isolation of the discharge nozzle 46 and the liquid path 47 of the gun body 44, are performed by the above-mentioned movement of the piston 56.

In the figure, reference numeral 71 denotes an urging spring when the piston 56 is moved so as to bring the ball valve 70 into contact with the valve seat 51, and 72 denotes a packing.
3 is a concave adapter for suppressing packing, code 74
Reference numeral 75 is a convex adapter for suppressing packing, reference numeral 75 is a cap nut for fixing the discharge nozzle 46, and reference numeral 76 is a packing.

The coating device according to the present invention has the configuration described above, and is operated as follows.

That is, to explain only the system of the pneumatic pump _P1 , the second switching valve 13 and the discharge gun 1
5 is in the closed position, and the pump rod 30 of the secondary reciprocating pump 7 has its tip 32 at 3 in FIG.
2', and the conduit 4
When the first switching valve 5 is opened and the pneumatic pump P ₁ is operated with the insides 9, 11, 3 and the pump chamber 36 filled with liquid, the liquid flows into the pump chamber of the secondary reciprocating pump 7. 36 is filled, and the hydraulic pressure acts on the end face of the tip 32 of the pump rod 30, so the pump rod 30 starts to rise as shown in _FIG . actuate to switch the first switching valve 5 to the closed position. Therefore, the filling of liquid into the pump chamber 36 of the secondary reciprocating pump 7 is cut off, and the pneumatic pump _P1 is stopped.

As mentioned above, the point in time when the limit switch dog 37 operates the limit switch LS ₁ is slightly before the tip 32 of the pump rod 30 takes the final retracted position in the pump chamber 36, so that the limit switch dog 37 operates the limit switch LS 1. In a state where there is a liquid filling margin in 36,
Filling by pneumatic pump _P1 will be cut off. Therefore, the inside of the pump chamber 36 is maintained at a pressure lower than the flow pressure of the pneumatic pump _P1 .

Now, assuming that there is no closing operation of the first switching valve 5 described above, the pressure in the pump chamber 36 increases until it reaches the stop pressure of the pump, that is, until it reaches equilibrium with (air pressure x pump ratio). However, due to the presence of the first switching valve 5, the only part that provides stopping pressure for the pump is the pipe 3 leading from the pneumatic pump _P1 to the first switching valve 5; While reaching the pump chamber 36, as described above, the pressure is kept below the pump flow pressure which is lower than the pump stop pressure.

In the above-described operation, since the check valve 77 is interposed in the pipe line 11 and the pipe line 11 is filled with liquid, the pipe line 11 is closed when the pump chamber 36 is filled with liquid. The liquid inside will not flow back or the filled liquid will not flow out into the pipe line 11.

Next, when the discharge gun 15 and the second switching valve 13 are opened, air is introduced into the piston front chamber 40 of the secondary reciprocating pump 7 to move the pump 7 to the discharge stroke, and the liquid is immediately discharged. It is discharged from the nozzle 46.

The pressure relationship of the liquid when the liquid is discharged from the discharge nozzle 46 will be explained with reference to FIG.
The vertical axis represents the pressure, the horizontal axis represents the position of each member in the pipeline system, the pressure PA is the stopping pressure of the secondary reciprocating pump 7, that is (air pressure x pump ratio), and the pressure PH is the secondary reciprocating pump 7 during flow. Next reciprocating pump 7
, pressure PV is the pressure inside the second switching valve 13 during flow, pressure PU is the discharge pressure of the discharge gun 15 during flow, and H is the pressure inside the secondary reciprocating pump 7.
Assuming that V is the position of the second switching valve 13 and U is the position of the discharge gun 15, the pressure of the liquid when the liquid is being discharged from the discharge nozzle 46 as described above is equal to that of the secondary reciprocating pump. Discharge pressure PH is discharge gun 1
The discharge pressure PU of 5 decreases due to pressure loss.

When the predetermined amount of discharge is completed, the discharge gun 15
and the second switching valve 13 is closed. As already mentioned,
Since this closing point is before the end of the discharge stroke of the secondary reciprocating pump 7, as mentioned above,
The pressure inside the pipe line 49 when the second switching valve 13 and the discharge gun 15 are in the closed position, that is, the discharge gun 15
The pressure PT in the liquid path 47 becomes the internal pressure at stop of (PV+PU)×1/2, and the pressure in the pipe 11 becomes the stop pressure PA of the secondary reciprocating pump 7.

Therefore, next, the second switching valve 13 and the discharge gun 1
5, the initial injection pressure of the discharge nozzle 46 when the discharge is reproduced is a pressure that decreases from the above-mentioned (PV + PU) x 1/2 to PU, which is a pressure close to the discharge pressure PU of the discharge gun 15. , the phenomenon of ejecting a large amount of liquid, so-called initial injection, is prevented.

If pneumatic pump P ₁ and discharge gun 15
A first switching valve 5, a secondary reciprocating pump 7,
Assuming that the second switching valve 13 is not provided and the pump P ₁ and the gun 15 are in direct communication with each other through a pipe line, when the discharge gun 15 is in the closed position, the above-mentioned communicating pipe is The pressure inside the passage becomes equal to the stop pressure of the pneumatic pump _P1 , and the initial injection pressure when the discharge gun ₁₅ is opened becomes large. However, in the present invention, such a phenomenon is completely eliminated by the presence of the secondary reciprocating pump 7.

As described above, the second switching valve 13 and the discharge gun 1
5 is closed, the secondary reciprocating pump 7 completes its discharge stroke, and at that point the first switching valve 5 is opened again, the secondary reciprocating pump 7 is filled with liquid, and the discharge gun 15 is restarted. This is a device that repeatedly discharges water from the tank.

The coating device according to the present invention has the above-described configuration,
Since it has a secondary reciprocating pump between the pneumatic pump and the discharge gun, it can absorb and eliminate the influence of pulsating flow caused by the pneumatic pump, making it suitable for line drawing of medium and high viscosity liquids. This has the effect of being able to perform the same operations uniformly.

In addition, the discharge volume of the secondary reciprocating pump in one operation is larger than the total discharge volume in one discharge operation of the discharge gun, and a switching valve is interposed between the discharge gun and the secondary reciprocating pump. filling of the secondary reciprocating pump with liquid is interrupted just before the pump chamber of the pump is filled, and the point at which the dispensing gun is placed in the closed position during dispensing is The fact that the timing is set before the end of the discharge stroke, etc., has the effect of effectively preventing the initial injection of the discharge gun.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an example of the embodiment, Fig. 2 is a vertical sectional view of an example of a secondary reciprocating pump, Fig. 3 is a longitudinal sectional view of an example of a discharge gun, and Fig. 4 is a longitudinal sectional view of an example of a discharge gun. FIG. 3 is a diagram showing the relationship between each position in the pipeline system and pressure. P ₁ , P ₂ : Pneumatic pump, 1, 2: Discharge port, 3, 4, 11, 12, 49, 59, 62: Pipe line, 5, 6: First switching valve, 7, 8: Second Secondary reciprocating pump, 9, 10: Secondary reciprocating pump discharge port, 13,
14: second switching valve, 15, 16: discharge gun.

Claims (1)

[Claims] 1 A pipe line that communicates with the discharge port of the pneumatic pump that sucks and discharges medium-high viscosity liquid communicates with the pump chamber of the secondary reciprocating pump via the first switching valve, and A pipe line communicating with the outlet communicates with the discharge gun via a second switching valve,
Discharging of the secondary reciprocating pump occurs when the second switching valve and the discharge gun simultaneously occupy an open position,
At this time, the first switching valve remains in the closed position, and before the end of the discharge stroke of the secondary reciprocating pump,
When the second switching valve and the discharge gun are in the closed position, and when the second switching valve and the discharge gun are in the closed position,
The member is configured such that the first switching valve occupies the open position and the secondary reciprocating pump enters the filling stroke, and the first switching valve is switched to the closed position before the filling of the pump chamber of the pump is completed. A drive circuit for medium-high viscosity liquid, characterized in that the secondary reciprocating pump has a single discharge volume that is larger than the total discharge volume during one discharge operation of the discharge gun. Coating device.