JPS6242767A - Method for controlling discharge quantity of multiple liquid paint - Google Patents

Abstract

PURPOSE:To supply a mixed liq. with high precision and to prevent defective coating by measuring the actual mass flow rate of the mixed liq. supplied at the specified number of revolutions of a gear pump and setting the number of revolutions of the gear pump to obtain the desired amt. of the paint to be discharged. CONSTITUTION:With respect to a method for controlling the discharge quantity of a multiple-liq. paint, may gear pumps 2 and 13 are rotated at high speed at the specified number of revolutions, the mass flow rate at that time based on the theoretical value is set and the actual mass flow rate is measured by mass flowmeters 8 and 19. When the difference between the actual mass flow rate and the theoretical mass flow rate is small, the numbers of revolutions of the gear pumps 2 and 13 are set to obtain the desired amts. of the plural paints to be discharged. Consequently, since the supply of the mixed liq. can be carried out with high precision and the defective coating such as dripping, lack of hiding, etc., can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for controlling the discharge amount of multi-liquid paint, and more specifically, a method for controlling the discharge amount of a multi-liquid paint, and more specifically, a method for measuring a plurality of mixed liquids according to the rotational speed of a plurality of gear pumps. The present invention relates to a method for controlling the discharge amount of a multi-liquid paint, in which the mixed liquid is mixed with the paint and discharged toward an object to be coated.

[Conventional technology]

Conventionally, for example, when a main agent such as a polyol and a curing agent such as an isocyanate are measured and mixed according to the rotational speed of each gear pump, and the mixed liquid is discharged toward the object to be coated, , it is necessary to keep the mixing ratio of the main agent and curing agent constant, and the following discharge rate control method is adopted.

(1) A gear pump is used to measure and supply the base agent and curing agent, and the rotation speed of the gear pump is fixed to measure and supply.
How to keep the mixing ratio constant.

(2) Japanese Patent Application Laid-Open No. 52-2761 (Patent Application No. 7126-1982
No. 8) As per the publication, the base agent is supplied by a plunger pump or pressure feeding, the curing agent is supplied by a gear pump, the flow rate of the base agent is measured by a flow meter, and the mixing ratio is made constant according to the flow rate of the base agent. A method of controlling the required amount of curing agent by the rotation speed of the gear pump and keeping the mixing ratio constant. In either method, the flow rate is guaranteed by the rotation speed of the gear pump.

[Problem that the invention seeks to solve]

However, in method (1), it has been confirmed that the flow rate changes depending on the viscosity of the base agent or curing agent, the differential pressure between the inlet side and the outlet side of the gear pump, etc. In fact, when we fixed the rotational speed of the gear pump and measured changes in the flow rate of the base agent and curing agent over time, we found that the flow rate fluctuation, which is thought to be due to changes in viscosity and differential pressure, varies depending on the type of gear pump.
Compared to the initial value, a maximum flow rate variation of 5 cc/min to 20 Cc/min was confirmed. When this paint was applied to an automobile body, paint defects such as delamination occurred, which was thought to be due to an abnormality in the mixing ratio.

In addition, when applying and mixing the base agent and curing agent using method (2) and painting the car body, we found that the total discharge amount varied, which was thought to be due to the quantitative nature of the plunger pump or pressure feeding that supplied the base agent. was large, and paint defects such as sagging and scratches frequently occurred.

Therefore, this invention was made to solve the above-mentioned problems, and it measures the actual flow rate of the mixed liquid supplied at a specific rotation speed of the gear pump with a mass flow meter,
By setting the rotational speed of the gear pump to obtain a desired amount of paint discharged based on the measured value, the purpose is to prevent coating defects such as delamination, sagging, and scratches after coating.

[Means for solving problems]

That is, in the multi-component paint discharge amount control method according to the present invention, a plurality of mixed liquids are supplied and mixed according to the rotational speed of a plurality of gear pumps, and the mixed liquid is discharged toward the object to be coated. A method for controlling the discharge amount of a multi-liquid paint, the method comprising: measuring the actual flow rate of a plurality of mixed liquids at a specific rotation speed of the plurality of gear pumps with a mass flow meter provided downstream of the gear pump; The rotation speed of the gear pump is set to obtain a plurality of desired paint discharge amounts based on the measured values.

In order to measure the actual flow rate of multiple mixed liquids at a specific rotational speed of the gear pump, it is necessary to measure at least one point in the high rotational speed region of the gear pump. It is desirable to measure multiple points in the high and low rotation speed ranges.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

(First Embodiment) Fig. 1 is a schematic diagram of a coating device used in the first embodiment of the present invention, and Fig. 2 is an explanation of the first embodiment of the multi-liquid paint discharge amount control method according to the present invention. The figure is shown below.

In Figure 1, 1 has one end as a supply source for the main agent (not shown).
The other end of the vibrator 1 is connected to a gear pump 2 that supplies 1.5 CC of the main agent per revolution (rpm), and a valve 3 is provided in the middle. Further, a rotating shaft 4a of an electric motor 4 is connected to the gear pump 2, and the electric motor 4 is connected to an inverter 6 via a conductive wire 5. The electric motor 4 is rotated by an instruction signal from the inverter 6, and the rotation speed of the gear pump 2 is controlled.

Further, a vibrator 7 is connected to the gear pump 2, and a mass flow meter 8 is provided in the middle thereof. A mixer 9 is connected to the tip of the vibrator 7, and a vibrator 11 having a spray gun 10 provided at the tip is connected to the mixer 9.

Further, a vibrator 12 is disposed near the vibrator 1, and one end of the vibrator 12 is connected to a curing agent supply source (not shown).
The other end is connected to a gear pump 13 that supplies 0.5 cc of curing agent per revolution (rpm), and a valve 14 is provided in the middle. Further, a rotating shaft 15a of an electric motor 15 is connected to the gear pump 13, and the electric motor 15 is connected to an inverter 17 via a conductive wire 16.

The electric motor 15 is rotated by an instruction signal from an inverter 17, and the rotation speed of the gear pump 13 is controlled.

Further, a vibrator 18 is connected to the gear pump 13, and a mass flow meter 19 is provided in the middle thereof. The tip of this pipe 18 is connected to a mixer 9 to which the pipe 7 on the base agent side is connected, and the base agent and curing agent are mixed and supplied from the pipe 11 to the spray gun 10. There is.

In addition, the mass flow meter 8 on the main agent side has a conductor connected to the inverter 6. ! 20 is connected so that the actual flow rate of the base agent measured by the xffi flowmeter 8 is fed back to the inverter 6.

Furthermore, an inverter 17 is connected to the mass flow meter 19 on the curing agent side.
A conductive wire 21 leading to is connected so that the actual flow rate of the curing agent measured by the mass flow meter 19 is fed back.

Next, a method for controlling the discharge amount of a multi-component paint consisting of a main agent and a curing agent will be explained based on FIGS. 1 and 2.

First, gear pump 2 on the base agent side and gear pump 1 on the hardener side.
3 high rotation speed range RO1 For example, the rotation speed on the main agent side is 20Or
pm, and the curing agent side is rotated at a high speed of 100 rpm, and the mass flow rate Vo is set based on the theoretical value of the base agent and curing agent at that time, and the actual flow rate Vr is measured by each mass flow meter 8. The ideal flow rate at this rotational speed, measured at No. 19, should be 300 cc/min for the base agent and 50 cc/min for the curing agent.

However, the viscosity of the base agent and curing agent, the gear pump 2
．． Due to the differential pressure between the inlet and outlet sides of 13, the actual flow rate V
r is different from the theoretical mass flow rate Vo. Therefore, at this time, the actual mass flow rate Vr and the theoretical mass flow rate Vo are compared. At that time, if the difference between the actual mass flow rate Vr and the theoretical mass flow rate Vo is larger than 1%, for example 15%, of the theoretical mass flow rate Vo, the pipe system for supplying the base agent or curing agent It is determined that there is an abnormality such as rupture or blockage, and the coating equipment will be stopped.

On the other hand, the difference between the real mass flow rate 1iVr and the theoretical mass flow rate ■0 is 1% of the theoretical mass flow rate Vo, for example, 15
%, the rotational speed of the gear pump 2.13 is set to obtain a plurality of desired paint discharge amounts. Specifically, as shown in FIG. 2, the gear pump 2.13
Draw a straight line Y toward the O rotation speed R where the motor has stopped.

and a first target flow rate V that requires a high discharge amount of paint,
When setting the rotation speed of the gear pump 2.13,
Target flow rate ■Draw a straight line Wa horizontally from part 8, and draw a straight line Y
When it comes into contact with the 11
Subtract wb. As a result, the rotation speed R8 of the gear pump 2.13 at the first target flow rate (1) is set.

In addition, when setting the rotation speed of the gear pump 2.13 for the second target flow rate ■2 that requires a low discharge amount of paint, draw a straight line Wc in the horizontal direction from the second target flow rate 72 parts, and draw a straight line Y When it comes into contact with
pull. As a result, the rotation speed R2 of the gear pump 2.13 at the second target flow rate (2) is set.

As described above, the preparation for coating the multi-component paint consisting of the base agent and the hardening agent is completed, and a constant amount of the base agent and the hardening agent are supplied to the mixer 9 according to the set rotational speed of the gear pump 2.13, and are sufficiently mixed. After that, it is sprayed from the spray gun 10 toward the object to be coated (not shown).

By the way, when we set the rotation speed of the gear pump 2.13 for the main agent side and the curing agent side according to the first example, and measured the mixing ratio of both parts for 7 days, we found that the mixing ratio of both parts was as shown in Fig. 3. Mixing ratio tolerance range ±! It was within ±5% of 0%. When the multi-liquid paint with this mixing ratio was applied to the objects to be painted, the result was good, with no occurrence of coating defects such as peeling between the eyebrows, sagging, and smearing.

In addition, using the same coating equipment as in the first example, the rotational speeds of the gear pumps 2.13 on the main agent side and hardening agent side were fixed, and the mixing ratio of both parts was measured over a period of 7 days.
As shown in FIG. 4, there were five times when the mixing ratio of the ryo-wari exceeded the allowable range of ±10%. When a multi-liquid paint with a mixing ratio of was applied to an object to be coated, delamination was observed when the coating was applied with a mixing ratio outside the allowable range.

(Second Embodiment) FIG. 5 is a schematic diagram of a coating device used in the second embodiment of the present invention, and FIG. 2 is an explanation of the second embodiment of the multi-liquid paint discharge amount control method according to the present invention. The figure is shown below.

The coating device shown in FIG. 5 used in this second embodiment is
This is the same as the coating apparatus described in the embodiment, and the same parts are given the same numbers and their explanations will be omitted.

Next, a method for controlling the discharge amount of a multi-component paint consisting of a main agent and a curing agent will be explained based on FIGS. 5 and 6.

First, gear pump 2 on the base agent side and gear pump 1 on the hardener side.
3 high rotation speed range RIG, for example, the rotation speed on the main agent side is 20
0 rpm, and the curing agent side is rotated at high speed at 1100 rpm. At that time, the mass flow rate V1° based on the theoretical value of the main agent and the curing agent is set, and the actual flow rate Vr is measured by each mass flow meter 8. Measure at 19. The ideal flow rate at this rotational speed should be 300 cc/min for the base agent and 50 cc/min for the curing agent.

In addition, the gear pump 2 on the main agent side and the gab 13 on the curing agent side have a low rotational speed range R, for example, the rotational speed on the main agent side is 8 Or
pm, and the curing agent side is rotated at a low speed of 4 Orpm, and the mass flow rate based on the theoretical value of the main agent and curing agent at this time is
, and measure the actual flow rate Vrz with each mass flowmeter 8.19. The ideal flow rate at this rotational speed should be 120 cc/min for the main agent and 20 ce/min for the curing agent.

However, the viscosity of the base agent or curing agent, the gear pump 2
．． The actual flow rate V is determined by the differential pressure between the inlet and outlet sides of 13.
r l % V r t is the mass flow rate based on the theoretical value.

, ■1. It is different from. Therefore, at this point, the high rotation speed range R
Actual flow rate Vr+ of 1° and mass flow rate V10 based on theoretical value
and the actual flow rate V in the low rotation speed range R11.
r, and the theoretical mass flow rate V++. At this time, the actual 'If quantity flow rate Vr on the high rotation speed range R3° side and the mass flow rate ■, based on the theoretical value. Difference between and low rotation speed range R11
One of the differences between the actual flow rate Vr2 on the side and the XN flow rate V11 based on the theoretical value is the mass flow t v r based on the theoretical value.
. , v+I is greater than T%, for example 15%, it is determined that there is an abnormality such as rupture or blockage of the pipe system that supplies the main agent or curing agent, and the coating apparatus is stopped.

On the other hand, the real flow rate Vr in the high rotational speed range RIG side is the mass flow rate ■ based on the theoretical value. Both the difference between the actual flow rate Vr2 in the low rotational speed region R11 side and the theoretical mass flow rate ■, the theoretical value mass flow rate ■1°, ■T% of Il, for example, 15%. If the amount of paint discharged is small, the rotation speed of the gear pump 2.13 is set to obtain a plurality of desired paint discharge amounts. Specifically, as shown in FIG. 6, a straight line Y is drawn between the actual flow rate Vr1 in the high rotation speed range R5° and the actual flow rate Vr in the low rotation speed range R11 of the gear pump 2.13.

When setting the rotation speed of the gear pump 2.13 for the first target flow 1v1□ that requires a high discharge amount, draw a straight line Wa in the horizontal direction from the first target flow tV1□, and draw a straight line Wa that corresponds to the straight line Y. At the point where they touch, draw a straight line wb at right angles 90' downward. As a result, the rotation speed R11t of the gear pump 2.13 at the target flow rate Vlt is set.

In addition, a second target flow rate V H that requires a low discharge amount of paint
3. When setting the rotation speed of the gear pump 2.13, draw a straight line Wc in the horizontal direction from the second target flow rate 701 parts, and when it touches the straight line Y, draw a straight line downward by 90 degrees at a right angle. Pull. As a result, the second target flow rate V + ff
The rotation speed R1ff of the gear pump 2.13 is set.

As described above, the preparation for coating a multi-component paint consisting of a base agent and a hardening agent is completed, and a constant amount of the base agent and hardener are supplied to the mixer 9 according to the set rotational speed of the gear pump 2.13, and are sufficiently mixed. After that, it is sprayed from the spray gun 10 toward the object to be coated (not shown).

By the way, according to the second example, the rotational speed of the gear pump 2.13 for the main agent side and the curing agent side was set, and the rotation speed of the gear pump 2.13 for the main agent side and the curing agent side was set to within ±2% of the allowable range of ±10% for the mixing ratio of Ryowari over a period of 7 days. was. When the multi-liquid paint with this mixing ratio was applied to the objects to be painted, the result was good, with no occurrence of coating defects such as peeling between the eyebrows, sagging, and smearing.

In addition, using the same coating equipment as in the second embodiment, the rotational speeds of the gear pumps 2.13 on the main agent side and hardening agent side were fixed,
When the mixing ratios on both sides were measured over a period of 7 days, as shown in FIG. 8, the mixing ratios on both sides deviated from the tolerance of ±10% five times. When a multi-liquid paint having this mixing ratio was applied to an object to be painted, peeling between the eyebrows was observed when painting with a mixing ratio outside the allowable range.

〔Effect of the invention〕

As invented above, in the multi-component paint discharge rate control method according to the present invention, the actual flow rate of the mixed liquid supplied at a specific rotation speed of the gear pump is measured with a mass flow meter, and based on the measured value. The rotation speed of the gear pump is set to obtain the desired paint discharge amount.
Since the mixed liquid can be supplied with high precision, it is possible to prevent coating defects such as peeling between the eyebrows, sagging, and scratches after coating.

In addition, in the present invention, even if an abnormality such as a rupture or blockage occurs in the pipe system that supplies the mixed liquid, it can be detected at an early stage, so that the life of the coating equipment W can be significantly extended. be.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a coating apparatus used in a first embodiment of the present invention. FIG. 2 shows the first method of controlling the discharge amount of multi-liquid paint according to the present invention.
It is an explanatory diagram in an example. FIG. 3 is a diagram showing changes over time in the mixing ratio of mixed liquids in the first embodiment of the present invention. - FIG. 4 is a diagram showing changes over time in the mixing ratio of mixed liquids in the conventional discharge amount control method. FIG. 5 is a schematic diagram of a coating device used in a second embodiment of the present invention. FIG. 6 shows the second method for controlling the discharge amount of multi-liquid paint according to the present invention.
It is an explanatory diagram in an example. FIG. 7 is a diagram showing changes over time in the mixing ratio of mixed liquids in the first embodiment of the present invention. FIG. 8 is a diagram showing changes over time in the mixing ratio of mixed liquids in the conventional discharge amount control method. 1.7.11.12.18...--Vibe 2.13-
--- Gear pump 4.15 --- Electric motor 4a, 15a --- Rotating shaft 5.16 --- Conductor 6.17 --- Inverter 8.19 -----Full flow meter 9m------Mixer 10---Spray gun 20.21---One conductor

Claims (1)

[Claims] Depending on the rotation speed of multiple gear pumps, multiple mixed liquids are
A multi-liquid paint discharge amount control method in which the mixed liquids are supplied and mixed, and the mixed liquids are discharged toward an object to be coated, the method comprising controlling the actual flow rate of the plurality of mixed liquids at a specific rotation speed of the plurality of gear pumps. , a multi-liquid system characterized in that the rotation speed of the gear pump is set in order to obtain a plurality of desired paint discharge amounts based on the measurement value measured by a mass flow meter installed on the downstream side of the gear pump. Method of controlling paint discharge amount.