JPH07187387A - Automatic paint supply device having flow rate control device - Google Patents

Abstract

PURPOSE:To prevent applied paint from being blown away by air blown off from a painting gun by forming a throat part between a blowing-into nozzle and a detecting tube, and making it perform an injection action. CONSTITUTION:Gas is blown into a detecting pipe 2 forming a detecting pipe line 1 having a constant inside diameter and powder 8 in a tank 9, and it is put in a fluid condition, and the powder 8 is sucked and introduced from an opening 2a of an inlet part 3 of the detecting pipe line 1 in a negative pressure condition. A pressure difference between an inlet and an outlet of the detecting pipe line 1 is detected by a differential pressure gauge through fluid resistors 10a and 11a, and a flow rate of the powder is calculated, and an adjusting valve 13 is adjusted. At this time, a throat part 24 is formed between a blowing- into nozzle 7 and the detecting pipe line 1, and when an injection action is exerted, a pressure loss of the detecting pipe line 1 can be eliminated. Thereby, since there is no need to increase a carrying air quantity, applied paint is prevented from being blown away by air blown off from a painting gun.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paint supply device having a flow rate control device used for powder coating or powder spraying equipment, and more particularly to a detection pipe having a constant inner diameter and a detection pipe for this detection. A blowing nozzle that blows a predetermined amount of detection fluid into the pipeline, a means for introducing powder into the detection pipeline, and a pressure difference detected at the pressure difference between the inlet and the outlet of the detection pipeline. The present invention relates to a paint automatic supply device having a flow rate control device including a flow rate control unit configured to calculate a powder flow rate based on a difference and adjust a detection pipeline outlet pressure based on the calculated powder flow rate.

[0002]

2. Description of the Related Art Conventionally, an automatic coating material supply device having a flow rate control device of this type has been disclosed in Japanese Patent Publication No. 3-7045 and Japanese Patent Application Laid-Open No. 62-64911. That is, as shown in FIG. 2, the inlet 3 has a constant inner diameter.
Detecting tube 2 forming a detecting conduit 1 having
Is blown into the inlet portion of the detection fluid 5 by a blowing nozzle 7 via a regulating means 6 for regulating the flow rate of the detection fluid 5 to a constant flow rate and a pipe line 7a. Of the powder 8 is introduced, and the pressure difference caused by the acceleration of the powder 8 by the detection conduit 1 is detected by the differential pressure gauge 12 via the fluid resistances 10a and 11a. The flow rate of the powder is calculated, and the outlet pressure of the detection conduit 1 is changed by adjusting the air pressure blown into the throat 15 by the main nozzle 14 with the adjusting valve 13 according to the calculated flow rate of the powder. The flow rate of powder carried by the carrying pipe 16 is adjusted.

The powder 8 in the tank 9 is in a flowing state by the gas 18 blown through the perforated plate 17 provided in the tank 9, and the inlet portion of the detection pipeline 1 in a negative pressure state. Is sucked into. In addition, the transport pipe 16
The auxiliary fluid supply pipe 20 downstream of the injector 15.
Is opened via the adjusting valve 21. Further, 22 is a pressure air source, and 23 is a supply stopping device that closes the annular elastic body with pressure from the surroundings to stop the powder supply.

[0004]

In the coating material automatic supply device having such a flow rate control device which has been already proposed, since a pressure loss of about 50 to 200 mmAq occurs in the detection pipe line, the powder transfer is performed. The injection efficiency of the injector 15 which is a means for
A large amount of carrier air is used as compared with the case where there is no detection circuit. Therefore, when it is used as a coating device, there is a problem that the amount of air blown from the coating gun is large, and the paint that has been applied is blown off by the large amount of transport air.

The present invention has been made in order to solve such a problem, and minimizes the pressure loss in the detecting portion so that the air blown from the coating gun does not blow off the applied paint. An object of the present invention is to provide an automatic paint supply device having a flow rate control device capable of detecting a body flow rate.

[0006]

A detection pipe having a constant inner diameter, a blowing nozzle for blowing a predetermined amount of a detection fluid into the detection pipe, and a powder introduced into the detection pipe. Means for detecting the pressure difference between the inlet and the outlet of the detecting pipeline, calculate the flow rate of the powder based on the detected pressure difference, and adjust the outlet pressure of the detecting pipeline based on the calculated flow rate of the powder. In an automatic paint supply device having a flow rate control device composed of an outlet pressure adjusting means, a throat part is formed between the blowing nozzle and the detection pipe line to have an injection action. Is.

[0007]

In the automatic paint supply device having the flow control device for detecting the pressure difference between the inlet and the outlet of the detecting pipe and adjusting the outlet pressure of the detecting pipe based on this pressure difference, the blowing nozzle and the detecting device are used. Since the throat portion was formed between the pipe and the injection function, the pressure at the inlet of the detection pipe, that is, the powder introduction part became a negative pressure than the pressure in the powder layer, and the detection was performed. The pressure loss in the pipeline can be compensated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with respect to an automatic paint supply device having a flow rate control device shown in the drawings.
In the drawings, the same or corresponding parts are designated by the same reference numerals.

As shown in FIG. 1, an automatic paint supply device having a flow rate control device for carrying out the present invention has a throat part 24 between the powder introduction part 2a and the inlet of the detection conduit 1. Except for the point where it is formed, it is almost the same as the automatic paint supply device having the conventional flow rate control device shown in FIG. That is, the gas 8 is blown into the powder 8 in the tank 9 and the powder 8 in the tank 9 through the porous plate 17 to flow the powder 8 through the porous plate 17 and the detection pipe 2 in which the detection pipe 1 having a constant inner diameter is formed. And a means for sucking and introducing the powder 8 from the opening 2a of the inlet portion 3 of the detection pipeline 1 in the negative pressure state, and the pressure difference between the inlet and the outlet of the detection pipeline 1 The detection pipe line 10 and the outlet side detection pipe line 11 are connected to a differential pressure gauge 12 via fluid resistances 10a and 11a, respectively, for detection, and the powder flow rate is calculated by the measurement value detected by the differential pressure gauge 12. The adjusting valve 13 is adjusted according to the calculated flow rate of the powder.

The adjusting valve 13 is adjusted so that the main nozzle 14 to the injector 15 for conveying the powder.
The air pressure to be blown into is changed to change the pressure at the outlet of the detecting pipe line 1 and the flow rate of the powder to be carried by the carrying pipe 16 is adjusted.

As a result of an experiment, the present invention shows that the blowing nozzle 7
It was made by discovering that the pressure loss of the detection conduit 1 disappears if the throat portion 24 is formed between the detection conduit 1 and the detection conduit 1 and exerts an injection action on the detection conduit 1. is there.

That is, an automatic paint supply device (a resin-made detection pipe having a detection pipe having a diameter of 5 mm) having the conventional fluid control device shown in FIG. 3, and as shown in FIGS. 4 and 5. The result of measuring the differential pressure and the actual discharge amount of the powder using the automatic paint supply device (the same detection tube as the conventional one) having the fluid control device of the invention of this application is shown in FIG.
As is clear from the line A in FIG. 6, in the conventional device, as the discharge amount increases, the detection conduit 1
The influence of friction loss in is large, and there is a discrepancy between the differential pressure and the actual discharge amount. The device of FIG. 4 is provided with a throat portion having an inner diameter of 3 mm at L = 30 mm upstream from the inlet of the detection conduit 1, and the result is shown by the line B of FIG. 6, and the device of FIG. L = 60 mm from the inlet of the detection pipe line 1
A throat portion having an inner diameter of 3 mm was provided upstream, and the result is shown by line C in FIG. Further, line B'in FIG.
5 is the result when the inner diameter of the throat portion is 4 mm in the apparatus of FIG.

FIG. 7 is a diagram showing the amount of air blown out from the blowout nozzle 7 and the negative pressure state of the portion into which the powder is introduced. Line A shows the result of the conventional apparatus, and lines B and B '. , C show the results of the apparatus of the present invention described above. As is apparent from FIG. 7, in the case of the present invention, the negative pressure is higher than that of the conventional device, and the introduction of the powder is good.

FIG. 8A shows the change in the pressure difference ΔP between the inlet and the outlet of the detection conduit 1 with respect to the blowing amount of the blowing nozzle 7 of the apparatus of the present invention, and similarly FIG. Shows the pressure difference ΔP at the inlet and outlet of the detection conduit 1 with respect to the blowing amount of the blowing nozzle 7 of the conventional device. By comparing FIGS. A and B, the difference in pressure loss in the detection line 1 between the conventional device and the device according to the present invention is clear. That is, in the conventional device, the detection conduit 1 remarkably increases as the blowing amount of the blowing nozzle 7 increases.
Although the pressure loss at
There is no such tendency.

FIG. 9A shows a change in pressure at the inlet of the detecting pipe 1 with respect to the blowing amount of the blowing nozzle 7 of the device of the present invention, and similarly, FIG. 9B shows the blowing of the conventional device. The change in pressure at the inlet of the detection conduit 1 with respect to the blowing amount of the injection nozzle 7 is shown. As understood from this result, in the conventional device, it was difficult to control the uniform introduction of the powder into the device by the amount of the detection fluid blown from the blowing nozzle 7. Is understood.

In the example described above, the throat portion is formed downstream of the means for introducing the powder, but it may be formed between the blowing nozzle and the means for introducing the powder in the same manner. It has an effect and an effect.

[0017]

According to the present invention, in the paint guidance and supply device having the flow rate control device using the detecting pipe, the throat portion is formed between the blowing nozzle and the detecting pipe to inject. Since it is provided, it is possible to reduce the friction loss in the detection pipe line, it is not necessary to increase the amount of air for conveyance, and the coating material is not blown off by the air blown from the coating gun. Therefore, uniform electrostatic coating is possible.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of an automatic paint supply device having a flow rate control device according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of an automatic paint supply device having a conventional flow rate control device.

FIG. 3 is a cross-sectional view of a main part of the device shown in FIG.

FIG. 4 is a cross-sectional view of the main parts of the device of FIG.

5 is a cross-sectional view of an essential part of the device of FIG. 4 with some modifications.

FIG. 6 is a diagram showing a relationship between the differential pressure ΔP and the actual discharge amount in the apparatus of FIGS.

FIG. 7 is a diagram showing a negative pressure state of the powder introduction portion with respect to the amount of detection fluid blown in the apparatus of FIGS. 3 to 5;

8 is a diagram showing a pressure difference in a detection pipe line with respect to a detection fluid injection amount of the device of FIGS. 4 and 5, and FIG. 8B is a detection fluid injection amount of the device of FIG. FIG. 5 is a diagram showing a pressure difference in a detection pipe line with respect to FIG.

9A is a diagram showing the pressure at the outlet of the detection conduit with respect to the amount of detection fluid blown in the device of FIGS. 4 and 5, and FIG.

[Explanation of symbols]

1 detection pipe 2 detection pipe 2a opening 3 inlet part 4 outlet 5 detection fluid 6 regulating means 7 blowing nozzle 7a pipe 8 powder 9 tank 10, 11 pipe 10a, 11a fluid resistance 12 differential pressure gauge 13, 21 Valve 14 Main Nozzle 15 Injector 16 Conveying Pipe 22 Pressure Air Source 23 Supply Stop Device 24 Throat ΔP Differential Pressure F ₂ Blow Amount P _P Supply Powder Pressure P _h Inlet Side Pressure

Claims (1)

[Claims] 1. A detection pipe having a constant inner diameter, a blowing nozzle for blowing a detection fluid of a predetermined flow rate into the detection pipe, a means for introducing powder into the detection pipe, and An outlet pressure adjusting means for detecting the pressure difference between the inlet and the outlet of the detection pipeline, calculating the powder flow rate based on the detected pressure difference, and adjusting the detection pipeline outlet pressure based on the calculated powder flow rate. In a paint automatic supply device having a flow rate control device consisting of, a flow rate control device characterized in that a throat portion is formed between the blowing nozzle and the detection pipe line to have an injection action. Automatic paint supply system.