JPH0716635B2 - Architectural coating material spraying machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spraying machine for architectural coating materials such as acrylic lysine, acrylic tiles or skins, and in particular, has a function of preventing the coating material jet pressure from becoming too high at the beginning of spraying. A coating material spraying machine for construction.

[0002]

2. Description of the Related Art First, an example of a conventional building material spraying machine will be described with reference to FIG. 1 showing an embodiment of the present invention.
Reference numeral 1 is a spray gun in which the coating material nozzle 2 is formed in an oblique posture at the tip and the air nozzle 3 is penetrated into the coating material nozzle 2 from the back side, and the coating material nozzle 2 is Discharge port 6 of mono pump 6 driven by motor 5
a is connected via a long coating material hose 7, one air nozzle 3 is connected to a compressor 9 via an air hose 8, and the spray gun 1 is coated with a coating material passage and an air passage by a lever operation (not shown). An on-off valve for coating material 10 and an on-off valve for air 11 that open and close in cooperation with each other are provided.
Further, the air flow switch 12 is attached to the air hose 8 described above.
Is provided so that the motor 5 is started and stopped in conjunction with its ON / OFF.

That is, the open / close valve 10 for coating material and air,
When 11 is opened in conjunction with each other, the pressurized air is supplied to the air nozzle 3, and the motor 5 is started via the air flow switch 12 in accordance with the supply of the air, whereby the coating material is discharged from the mono pump 6. Coating material hose 7
In addition, it is supplied to the coating material nozzle 2 through the coating material opening / closing valve 10, and the coating material is ejected in the form of particles by the above-mentioned pressurized air and sprayed on the surface to be coated.

On the other hand, when the on-off valves 10 and 11 are closed, the supply of pressurized air is stopped and the motor 5
In addition, the mono pump 6 stops, and the spraying stops.

[0005]

By the way, looking at the pressure distribution in the coating material hose 7 in such a spraying machine, at the time of normal spraying, as shown by the characteristic line a in FIG. The discharged coating material is the coating material hose 7
It is decompressed by the pressure loss of and becomes low pressure on the gun side.

When the on-off valves 10 and 11 are closed to stop the spraying, the mohno pump 6 is stopped and the discharge of the coating material is stopped, and the coating material remains in the coating material hose 7. The pressure distribution becomes uniform over the entire length of the hose as the characteristic line b in the figure with the passage of time, and the pressure on the gun side becomes considerably higher than that at the time of spraying.

Therefore, when the on-off valves 10 and 11 are opened again when the spraying is resumed, an extremely large amount of coating material is ejected at the beginning of the spraying compared with the time of the normal spraying, and the unevenness is caused on the surface to be coated. Will be created. For this reason, spraying for repairs is required, which lowers the work efficiency, and if the coating material is thrown away at the beginning to avoid it, not only is the coating material wasted wastefully, but also at the work site. It has resulted in mischief.

[0008]

DISCLOSURE OF THE INVENTION The building material sprayer of the present invention has been completed in view of the above points, and the motor is a reversible motor for driving the pump in forward and reverse directions. Detecting means for detecting that the reversible motor has stopped from forward rotation, a timer for outputting a predetermined time operation signal based on the detection signal from the detecting means, and a pressure sensor for detecting the pressure at the discharge port of the pump. Input means for previously inputting a reference pressure for comparison with the detected pressure, and a first control step for operating the reversible motor in a reverse direction while operating by an operation signal from a timer and receiving the operation signal, The motor drive control means repeatedly executes a second control step of stopping the reversible motor for a certain period of time when the detected pressure becomes equal to or lower than the reference pressure.

[0009]

When the forward rotation of the reversible motor is stopped when the spraying is stopped, and the detection means detects it, the time substantially matched with the time when the discharge of the coating material is stopped and the pressure distribution in the coating material hose becomes uniform. After the delay, the timer outputs an operation signal for a predetermined time to the motor drive control means.

When the motor drive control means receives the operation signal, the reversible motor is first driven in reverse as a first control step. As a result, the pressure on the pump side is reduced due to the uniform pressure distribution.

The pressure on the pump side is continuously detected by the pressure sensor, and as a second control step, the reversible motor is stopped for a certain period of time when the detected pressure becomes equal to or lower than the previously input reference pressure. During the stop time, the pressure distribution of the coating material becomes uniform again, but since the pressure on the pump side is forcibly reduced, the pressure value becomes smaller than before.

After a lapse of a certain motor stop time, the above-mentioned first control step is executed again to reduce the pressure on the pump side, and then the second control step is executed.
Further, a uniform pressure distribution having a small pressure value is obtained, and the first and second control steps are repeatedly executed while receiving the operation signal from the timer.

As a result, when the motor control is completed, the pressure inside the coating material hose becomes a uniform pressure distribution with an extremely small pressure value, that is, the pressure on the gun side is reduced to the same level as during normal spraying. When spraying on
Immediately after opening the on-off valve, the coating material is ejected at a substantially constant ejection pressure.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In this embodiment, a reversible motor is used as the motor 5 that drives the mono pump 6. The drive of the reversible motor 5 is controlled by a signal from the motor drive control means 20, and when the ON signal is received from the air flow switch 12 provided in the air hose 8 described above, the reversible motor 5 is driven normally. It is designed to rotate.

The motor drive control means 20 stores in advance a motor drive program for lowering the coating material pressure on the gun side according to the present invention. Next, the configuration of peripheral devices and programs will be described.

A timer 21 is connected to the air flow switch 12 described above. The timer 21 outputs a predetermined delay time to the motor drive control means 20 when the air flow switch 12 is switched from ON to OFF. , The function of sending an operation signal for executing the above program for a predetermined time is fulfilled.

A pressure sensor 22 for detecting the discharge pressure of the coating material is connected to the pump side of the coating material hose 7, and the detection signal is input to the motor drive control means 20. Further, the motor drive control means 20 is connected to an input means 23 for presetting and inputting a reference pressure to be compared with the detected pressure.

The motor drive program is composed of two control steps. In the first control step, the reversible motor 5 is reversely driven, and in the second control step, the detected pressure obtained from the pressure sensor 22 is input means. The reversible motor 5 is stopped for a certain period of time when the pressure becomes equal to or lower than the reference pressure input from 23.
The control step is repeated while the operation signal is being obtained from the timer 21, and is set to be repeated twice in this embodiment.

Next, the operation of this embodiment will be described. When the on-off valves 10 and 11 are opened, pressurized air is supplied to the air nozzle 3 and the air flow switch 12 is turned on, whereby the reversible motor 5 is driven in the forward direction via the motor drive control means 20 and the coating material is applied from the mono pump 6. The fact that is discharged and sprayed is the same as described in the section of the prior art, and the pressure distribution of the coating material at the time of spraying is as shown by the characteristic line a in FIG. 3 as described above.

The on-off valves 10 and 11 when the spraying is stopped
Is closed, the forward rotation of the reversible motor 5 is stopped in the same manner as when the airflow switch 12 is turned off. However, when it is detected that the airflow switch 12 is switched from ON to OFF, a constant delay time is detected. After that, timer 21
The motor drive control means 20 outputs an operation signal for driving a program for a predetermined time. Meanwhile, the pressure distribution of the coating material is as shown by the characteristic line b in FIG.
It becomes uniform at relatively high pressure.

When the motor drive control means 20 receives the operation signal and executes the program, as shown in the flow chart of FIG. 2, the reversible motor 5 is first used as the first control step.
Drive in reverse. As a result, the pressure on the pump side is gradually reduced due to the uniform pressure distribution of the characteristic line b.

The pressure on the pump side is continuously detected by the pressure sensor 22, and as shown by the characteristic line c, when the detected pressure falls to the reference pressure, the reversible motor 5 is stopped for a certain period of time as a second control step. . During the fixed stop time, the pressure distribution of the coating material becomes uniform again, but the pressure value becomes smaller as compared with the previous characteristic line d because the pressure on the pump side is forcibly reduced.

After a lapse of a certain motor stop time, the above-mentioned first control step is executed again, the pressure on the pump side is lowered, the pressure distribution becomes as shown by the characteristic line e, and the second control step is executed subsequently. As a result, a uniform pressure distribution with a smaller pressure value is obtained as shown by the characteristic line f, and at the same time, the execution of the program ends.

As a result, at the stage when the motor control is completed, the inside of the coating material hose 7 has a uniform pressure distribution with a very small pressure value as shown by the characteristic line f, that is, the pressure on the gun side during normal spraying. When the spraying is performed next, the coating material can be jetted at a substantially constant jetting pressure immediately after the opening / closing valves 10 and 11 are opened.

It should be noted that the first and second control steps of the program may be repeated three times or more, whereby the pressure on the gun side of the coating material in standby can be made closer to the pressure during normal spraying. Becomes

In the present invention, the pressurized air is blown off,
The present invention can be similarly applied to a spraying machine of a type in which opening and closing of a coating material on-off valve and ON / OFF of a motor are switched by a switch to control only supply and stop of coating material. Further, the present invention is not limited to the mohno pump shown in the above-described embodiment, but can be widely applied to all spraying machines using other rotary positive displacement pumps such as a tubing pump.

[0027]

As described above in detail, according to the present invention, the pressure on the gun side is dropped to the same level as that during normal spraying between the time when spraying is stopped and the time when spraying is restarted. When the spraying is restarted, the coating material can be sprayed from the beginning with a substantially constant spraying pressure, and uniform spraying can be performed. As a result, it is possible to significantly improve the work efficiency by eliminating the need for spraying for repairing, for example, in the case of unevenness, and since waste blowing is also unnecessary, the coating material is not wasted and the cost is reduced. It is possible to contribute to the saving and to prevent the work site from being dirty unnecessarily.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a flow chart of its operation.

FIG. 3 is an explanatory diagram of pressure distribution of a coating material.

[Explanation of symbols]

1: Spray gun 2: Coating material nozzle 3: Air nozzle 5:
Reversible motor 6: Mono pump 6a: Discharge port 7: Coating material hose 8: Air hose 9: Compressor 10: Coating material opening / closing valve 12: Air flow switch (detection means) 20: Motor drive control means 21: Timer 2
2: Pressure sensor 23: Input means

Claims (1)

[Claims] 1. A spray gun having a coating material nozzle for jetting coating material at its tip and an air nozzle for jetting pressurized air facing the coating material nozzle is driven by a motor through an on-off valve. Connected to the discharge port of the rotary displacement type pump with a long coating material hose, while supplying pressurized air to the air nozzle,
By opening the open / close valve and driving the pump, the coating material is sprayed in a granular form from the coating material nozzle and sprayed on the surface to be coated, and the spraying is stopped by closing the open / close valve and stopping the pump. In the architectural coating material spraying machine configured to do so, the motor is a reversible motor that drives the pump forward and backward, and a detecting unit that detects that the reversible motor has stopped from forward rotation, and the detecting unit A timer that outputs an operation signal for a predetermined time based on the detection signal of, a pressure sensor that detects the pressure of the discharge port of the pump, and an input unit that inputs a reference pressure for comparison with the detected pressure in advance. A first control step that operates in response to the operation signal from the timer and drives the reversible motor in a reverse direction while receiving the operation signal, and the detected pressure is the basic control step. Building coating material sprayer, characterized by comprising a motor drive control means for performing repeatedly a second control step of the stopping reversible motor fixed time and a pressure below the.