JPH0249145B2 - TAEKITORYONOTOSHUTSURYOSEIGYOHOHO - Google Patents

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.
More specifically, it relates to a multi-liquid paint discharge amount control method in which a plurality of mixed liquids are measured and mixed according to the rotational speed of a plurality of gear pumps, and the mixed liquid is discharged toward an object to be coated. be.

[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 method in which a gear pump is used to measure and supply the base agent and curing agent, and the rotational speed of the gear pump is fixed to measure and supply, thereby keeping the mixing ratio constant.

(2) As disclosed in Japanese Patent Application Laid-Open No. 52-2761 (Japanese Patent Application No. 51-71268), the base agent is supplied by a plunger pump or pressure feeding, the curing agent is supplied using a gear pump, and the flow rate of the base agent is measured using a flow meter. Turn it over and measure it.
A method of keeping the mixing ratio constant by controlling the amount of curing agent required to keep the mixing ratio constant according to the flow rate of the base agent by controlling the rotation speed of the gear pump. In either method, the flow rate is guaranteed by the rotational 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 speed of the gear pump and measured changes in the flow rates of the base agent and curing agent over time, we found that the flow rate fluctuations, which are thought to be due to changes in viscosity and differential pressure, differed from the initial values depending on the type of gear pump. Fluctuations in the flow rate from a maximum of 5 c.c./min to 20 c.c./min were 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 fluctuated, which was thought to be due to the quantitative nature of the plunger pump that supplied the base agent or the pressure feeding. was large, and paint defects such as sagging and scratches frequently occurred.

Therefore, the present 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 flowmeter, and calculates the flow rate based on the measured value. The purpose is to prevent coating defects such as delamination, sagging, and smearing after coating by setting the rotation speed of the gear pump to obtain a desired paint discharge amount.

[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 flow meter provided on the downstream side 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.

The measurement position of the actual flow rate of multiple mixed liquids at a specific rotation speed of the gear pump requires at least one measurement in the high rotation speed range of the gear pump. It is desirable to measure multiple points in the high rotation speed range and low rotation speed range.

〔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-component paint discharge amount control method according to the present invention. The figure is shown below.

In FIG. 1, 1 is a pipe whose one end is connected to a supply source (not shown) of the base agent, and the other end of the pipe 1 is connected to a supply source of the base agent (not shown), and the other end of the pipe 1 supplies 1.5 cc of the base agent per rotation (rpm).
It is connected to a gear pump 2 that supplies the fuel, 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 pipe 7 is connected to the gear pump 2, and a flow meter 8 is provided in the middle of the pipe 7.
A mixer 9 is connected to the tip of the pipe 7, and a pipe 11 having a spray gun 10 at its tip is connected to the mixer 9.

Further, a pipe 12 is arranged near the pipe 1, and one end thereof is connected to a curing agent supply source (not shown), and the other end supplies 0.5 cc of curing agent per rotation (rpm). It is connected to a gear pump 13, 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 pipe 18 is connected to the gear pump 13, and a flow meter 19 is provided in the middle of the pipe 18. 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.

Further, a conductor 20 leading to the inverter 6 is connected to the flow meter 8 on the base agent side, so that the actual flow rate of the base agent measured by the flow meter 8 is fed back to the inverter 6. Furthermore, a conductor 21 leading to the inverter 17 is connected to the flow meter 19 on the hardening agent side, so that the actual flow rate of the hardening agent measured by the 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, the high rotation speed range Ro of the gear pump 2 on the main agent side and the gear pump 13 on the hardener side, for example, the rotation speed on the main agent side is 200 rpm, and the rotation speed on the hardener side is 100 rpm.
Rotate at high speed with
Vr is measured with each flow meter 8, 19. The ideal flow rate at this rotation speed is
300c.c./min and the curing agent should be 50c.c./min.

However, the actual flow rate Vr differs from the theoretical flow rate Vo depending on the viscosity of the main agent and curing agent and the differential pressure between the inlet and outlet sides of the gear pumps 2 and 13. Therefore, at this time, the actual flow rate Vr and the theoretical flow rate Vo are compared. At that time, the difference between the axial flow rate Vr and the theoretical value flow rate Vo is the theoretical value flow rate
If T% of Vo is greater than 15%, for example,
It is determined that there is an abnormality such as rupture or blockage in the pipe system that supplies the main agent or hardening agent, and the coating equipment is stopped.

On the other hand, if the difference between the actual flow rate Vr and the theoretical flow rate Vo is smaller than T% of the theoretical flow rate Vo, for example 15%, the gear pumps 2 and 13 are adjusted to obtain the desired multiple paint discharge amounts. Set the rotation speed. Specifically, as shown in FIG. 2, a straight line Y is drawn from the actual flow rate Vr in the high rotation speed range Ro of the gear pumps 2 and 13 toward 0 rotation speed R where the gear pumps 2 and 13 are stopped.

When setting the rotation speed of the gear pumps 2 and 13 for the first target flow rate _V1 that requires a high discharge amount of paint, draw a straight line Wa horizontally from the first target flow rate _V1 , and When it comes into contact with Y, draw a straight line Wb at a right angle 90 degrees downward. Thereby, the gear pump 2 at the first target flow rate V ₁ ,
A rotation speed R ₁ of 13 is set.

In addition, when setting the rotation speed of _the gear pumps 2 and 13 for the second target flow rate _V2 , which requires a low discharge amount of paint, it is necessary to
Draw Wc, and when it touches the straight line Y, draw a straight line Wb at a right angle downward by 90 degrees. By this,
Gear pump 2, 13 at second target flow rate V ₂
The rotation speed _R2 is set.

As described above, the preparation for painting the multi-liquid paint consisting of the main agent and the curing agent is completed, and the gear pump 2, which has been set,
A constant amount of the main agent and curing agent are supplied to the mixer 9 according to the rotational speed of the main agent 13, and after being thoroughly mixed, they are sprayed from the spray gun 10 toward the object to be coated (not shown).

By the way, according to the first embodiment, the rotation speeds of the gear pumps 2 and 13 on the main agent side and hardening agent side are set,
When the mixing ratio of both drugs was measured over a period of 7 days, it was within ±5% of the allowable range of ±10% for the mixing ratio of both drugs, as shown in FIG. and,
When the multi-component 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 interlayer peeling, sagging, and sagging.

In addition, by using the same coating equipment as in the first embodiment, the gear pumps 2 and 13 on the main agent side and hardening agent side were
When the mixing ratio of both drugs was measured over a period of 7 days with the rotation speed fixed, as shown in Figure 4, the mixing ratio of both drugs deviated from the allowable range of ±10% five times. 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 apparatus shown in FIG. 5 used in this second embodiment is the same as the coating apparatus described in the first embodiment, and the same parts are given the same numbers and the explanation thereof will be omitted.

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

First, set the high rotation speed range R ₁₀ of the gear pump 2 on the base agent side and the gear pump 13 on the hardener side, for example, set the rotation speed on the base agent side to 200 rpm, and set the rotation speed on the hardener side to 200 rpm.
Rotate at a high speed of 100 rpm, set the flow rate V ₁₀ based on the theoretical value of the main agent and curing agent at that time, and measure the actual flow rate Vr ₁ with the respective flow meters 8 and 19. The ideal flow rate at this rotational speed should be 300 c.c./min for the base agent and 50 c.c./min for the curing agent.

In addition, the gear pump 2 on the base agent side and the gear pump 13 on the hardener side are rotated at low speed R ₁₁ , for example, the rotation speed on the base agent side is 80 rpm, and the rotation speed on the hardener side is 40 rpm. Set the theoretical flow rate V ₁₁ with the agent, and also set the actual flow rate Vr ₂
is measured by the respective flowmeters 8 and 19. The ideal flow rate at this rotation speed is 120
cc/min, and the curing agent should be 20 c.c./min.

However, the actual flow rates Vr ₁ and Vr ₂ differ from the theoretical flow rates V ₁₀ and V ₁₁ due to the viscosity of the main agent or curing agent and the differential pressure between the inlet and outlet sides of the gear pumps 2 and 13. Therefore, at this point, the actual flow rate Vr ₁ in the high rotation speed range R ₁₀ is compared with the theoretical flow rate V ₁₀ , and the actual flow rate Vr ₂ in the low rotation speed range R ₁₁ is compared with the theoretical flow rate V ₁₁ . do. At that time, high rotation speed range
Either the difference between the actual flow rate Vr ₁ on the R ₁₀ side and the theoretical flow rate V ₁₀ or the difference between the actual flow rate Vr ₂ on the low rotation speed region R ₁₁ side and the theoretical flow rate V ₁₁ is based on the theoretical value. If T% of the flow rates V ₁₀ and V ₁₁ is greater than, for example, 15%, it is determined that there is an abnormality such as rupture or blockage of the pipe system for supplying the main agent or curing agent, and the coating apparatus is stopped.

On the other hand, both the difference between the actual flow rate Vr ₁ on the high rotation speed range R ₁₀ side and the theoretical flow rate V ₁₀ , and the difference between the actual flow rate Vr ₂ on the low rotation speed range R ₁₁ side and the theoretical flow rate V ₁₁ . However, when T% of the theoretical flow rates V ₁₀ and V ₁₁ is smaller than, for example, 15%, the rotational speed of the gear pumps 2 and 13 is set to obtain a plurality of desired paint discharge amounts. Specifically, as shown in Figure 6, the actual flow rate in the high rotation speed range _R10 of gear pumps 2 and 13
A straight line Y is drawn between Vr ₁ and the actual flow rate Vr ₂ in the low rotation speed range R ₁₁ .
pull.

and the first target flow rate that requires a high discharge amount.
When setting the rotation speed of the gear pumps 2 and 13 of V ₁₂ , draw a straight line Wa horizontally from the first target flow rate V ₁₂ .
When it touches the straight line Y, draw a straight line Wb at a right angle downward by 90 degrees. Thereby, the rotation speed R ₁₂ of the gear pumps 2, 13 at the first target flow rate V ₁₂ is set.

In addition, when setting the rotation speed of the gear pumps 2 and ₁₃ for the second target flow rate _V13 that requires a low paint discharge amount, it is necessary to
Draw Wc, and when it touches the straight line Y, draw a straight line 90 degrees downward at a right angle. By this, the second
The rotation speed R 13 of the gear pumps 2 and ₁₃ at the target flow rate V ₁₃ is set.

As described above, the preparation for coating the multi-component paint consisting of the main agent and the curing agent is completed, and the gear pumps 2 and 1 are set.
A constant amount of the main agent and curing agent are supplied to the mixer 9 in accordance with the rotational speed of the main agent 3, and after being thoroughly mixed, they are sprayed from the spray gun 10 toward the object to be coated (not shown).

By the way, according to the second embodiment, the rotation speeds of the gear pumps 2 and 13 on the main agent side and hardening agent side are set,
Tolerable range of mixing ratio of both drugs over 7 days ±10%
However, it was within ±2%. 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 delamination, sagging, and sagging.

In addition, using the same coating equipment as in the second embodiment, the rotation of the gear pumps 2 and 13 on the main agent side and hardening agent side was fixed, and the mixing ratio on both sides was measured for 7 days. As shown in the figure, there were five times when the mixing ratio on both sides deviated from the allowable range of ±10%. When the multi-liquid paint having this mixing ratio was applied to an object to be painted, delamination was observed when the paint was applied with a mixing ratio outside the permissible 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 flow meter, and based on the measured value. Since the rotation speed of the gear pump is set to obtain the desired amount of paint discharged, the mixed liquid can be supplied with high precision, thereby preventing coating defects such as delamination, sagging, and sagging after painting. This has the effect of preventing the occurrence of.

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

[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 is an explanatory diagram of the first embodiment of the multi-liquid paint discharge amount control method according to the present invention. FIG. 3 is a diagram showing changes over time in the mixing ratio of mixed liquids in the first embodiment of the present invention. Fourth
The figure is a diagram showing changes over time in the mixing ratio of mixed liquids in a 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 is an explanatory diagram of a second embodiment of the multi-liquid paint discharge amount control method according to the present invention. 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...pipe, 2, 1
3... Gear pump, 4, 15... Electric motor, 4
a, 15a...rotating shaft, 5, 16... conducting wire, 6,
17...Inverter, 8, 19...Flowmeter, 9...
...Mixer, 10...Spray gun, 20, 21...
...conductor.

Claims (1)

[Claims] 1. A multi-liquid paint discharge amount control method in which 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 an object to be coated, the method comprising: In order to measure the actual flow rate of multiple mixed liquids at a specific rotation speed of the gear pump with a flow meter installed on the downstream side of the gear pump, and obtain the desired multiple paint discharge amounts based on the measured value. A method for controlling the discharge amount of multi-liquid paint, which comprises setting the rotation speed of a gear pump.