JPH0113044B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a device for preparing viscous liquids such as paints (hereinafter referred to as stock solutions), and more specifically, the present invention relates to a device for preparing viscous liquids such as paints (hereinafter referred to as stock solutions). This invention relates to a device for dosing and metering.

Purpose The present invention aims to automate a mixing operation where the required mixing amount and mixing precision for each stock solution are wide-ranging, such as in the mixing of paints, etc. It is an object of the present invention to provide an automatic injection/measuring device capable of efficiently injecting stock solutions of primary color paints and the like into separate containers with the required precision.

Configuration Hereinafter, the present invention will be explained in detail according to examples.

Fig. 1 shows an automatic blending device equipped with a plurality of devices of the present invention, and 1 is a sealed stock solution tank containing a stirring tool 3 driven by an air motor 2, which stores stock solutions A, B, C, and so on, respectively. A liquid supply pipe 4 for carrying out the stock solution is provided at the bottom, and the pressure inside the tank is regulated by a pressure regulator 7 connected to an air header 5 and controlled by a control device 6. Two discharge valves 8-1 and 8-2 are installed in the liquid feed pipe 4 of each stock solution tank 1.
A discharge nozzle 9-1, 9-2 formed of a thin tube having a uniform diameter is provided at the tip of each discharge valve. One discharge nozzle 9-1 has a large diameter, and the other discharge nozzle has a small diameter. 10-
Reference numerals 1 and 10-2 are solenoid valves connected to the discharge valves 8-1 and 8-2, respectively, and whose opening and closing are controlled by the control device 6. When the solenoid valves 10-1 and 10-2 open, the air is discharged from the air header 5. Discharge valve 8 by air pressure
-1, 8-2 open, solenoid valve 10-1, 10-2
Although only those corresponding to a pair of discharge valves 8-1 and 8-2 provided in one stock solution tank 1 are shown in the figure, electromagnetic valves are similarly provided for the other discharge valves. ing.

The stock solution in each stock solution tank 1 is transferred to the liquid supply pipe 4, the discharge valve 8-1 or 8-2, and the discharge nozzle 9-1 or 9- by the pressurizing force of air or inert gas such as nitrogen gas from the air header 5'. 2 and into the receiver 11. At this time, the pressure applied to each stock solution tank is adjusted by the pressure regulator 7 so that the discharge speed of the stock solution discharged from each discharge nozzle 9-1, 9-2 becomes a predetermined value regardless of the viscosity of the stock solution. . 12 is a pressure gauge that detects the pressurizing force of the stock solution tank 1 and transmits the signal to the control device 6.

Reference numeral 13 denotes an electronic balance that detects the weight of the stock solution injected into the receiver 11, and detects the weight when the discharge valve is opened and the stock solution is being injected, that is, the dynamic weight, and the predetermined time after the discharge valve is closed. The weight after the lapse of time, that is, the electrostatic weight is detected and the signal is sent to the control device 6.
Send to.

Reference numeral 15 denotes a lifting device for the receiver 11, and the receiver 11 is moved onto the electronic balance 13 and transferred to another predetermined position by the lifting device 15 and a transport device (not shown). 16 is a thermometer that detects the temperature of the stock solution and transmits the signal to the control device 6.

The control device 6 consists of a microcomputer and an input/output interface, and controls the stock solution contained in each stock solution tank 1 based on the setting conditions and operating conditions entered in advance by tape or key, and the signals input from each of the above-mentioned detectors. The pressure regulator 7 and the solenoid valves 10-1, 10- are set so that a predetermined injection amount can be obtained under a predetermined injection pressure in accordance with a predetermined mixing order.
2, and when the completion of injection of each stock solution, that is, completion of preparation, is detected, the solenoid valve 14 is controlled to operate the lifting device and the conveying device.

An embodiment of the present invention will be explained in more detail in FIG.

20 is a viscosity/specific gravity correction circuit, and a temperature detector 16
Using the detected temperature as an input signal, the viscosity and specific gravity of the stock solution are corrected using the clay-temperature table and the specific gravity-temperature table. 21 is a discharge pressure calculation circuit;
The viscosity corrected by the viscosity/specific gravity correction circuit 20, the discharge speed, the discharge pressure correction constant, and the nozzle conditions (aperture,
The discharge pressure is calculated by inputting the setting value of
And the pressure regulator 7 is controlled via the comparison control circuit 22 so that the discharge speed of the stock solution from the second discharge nozzle becomes a predetermined value. The comparison control circuit 22 inputs the discharge pressure signal calculated by the discharge pressure calculation circuit 21 or the set micro-injection discharge pressure signal according to the signal from the comparison circuit 23, and the signal of the pressure detector 12 corresponds to those discharge pressure signals. The pressure regulator 7 is controlled to match the pressure. These viscosity/specific gravity correction circuits 2
0, the discharge pressure calculation circuit 21 and the comparison control circuit 22 constitute a discharge pressure control means.

24 is a discharge control value calculation circuit which inputs the discharge control value constant, the nozzle diameter, and the specific gravity of the stock solution corrected by the viscosity/specific gravity correction circuit 20, and calculates the first and second discharge nozzles under a predetermined discharge speed. The discharge control value is calculated.

Reference numeral 25 denotes an injection remaining amount calculation circuit, which uses the dynamic or static injection amount detected by the weight detector (electronic balance) 13 as an input signal to calculate the dynamic or static injection amount between this injection amount and the target injection amount of the stock solution. Calculate quantities.

The comparison circuit 23 compares the target injection amount of the stock solution or the dynamic or static injection remaining amount from the injection remaining amount calculation circuit 25 and the discharge control value from the discharge control value calculation circuit 24, or compares the discharge control value from the discharge control value calculation circuit 24 with the allowable injection error amount of the stock solution. The static remaining injection amount from the remaining injection amount calculation circuit 25 is compared, and based on the comparison result, the opening/closing of the first discharge valve 8-1 and the second discharge valve 8-2 is controlled via the discharge valve opening/closing control circuit 26. Control.

If the target injection amount of the stock solution is less than or equal to the discharge control value of the second discharge nozzle from the discharge control value calculation circuit 24, or if the static injection remaining amount from the injection remaining amount calculation circuit 25 is larger than the allowable injection error amount of the stock solution. If it is less than the discharge control value of the second discharge nozzle, the comparison circuit 23 sends a signal to the comparison control circuit 22 to control the pressure regulator 7 so that the discharge pressure becomes the micro-injection discharge pressure. In this case, the second discharge valve opening/closing time calculation circuit 27 inputs signals from the remaining injection amount calculation circuit 25, the discharge valve opening/closing control circuit 26, and the timer 28 under this micro-injection discharge pressure, and Measure the minimum unit discharge amount and discharge time of the stock solution discharged from the second discharge nozzle under the injection discharge pressure, and send a signal to control the opening and closing time of the second discharge valve based on the measurement results. The signal is sent to the control circuit 26.

Next, the operation of setting the discharge speed of the stock solution to a predetermined value will be explained.

In this apparatus, it is preferable for the discharging speed of the stock solution to be as fast as possible without the discharged stock solution scattering outside the receiver 11 in terms of mixing efficiency.

In this device, the discharge speed of the stock solution is determined by the Reynolds number
If Re is less than 2300, the flow becomes laminar and Hagen
Since Poiseuille's law is almost applicable, it can be calculated using the following formula.

V=P/8μ・l(d/2) ² ………(1) However, V: Discharge speed (cm/sec), P: Discharge pressure (gr/cm ² ), μ: Stock solution viscosity (gr・sec) /cm ² ), l: Length of the discharge nozzle (cm), d: Diameter of the discharge nozzle (cm) In other words, conduct a discharge experiment with a low viscosity liquid using an arbitrary discharge nozzle, and perform a discharge experiment with a low viscosity liquid to the extent that the undiluted liquid does not scatter. The highest discharge pressure is experimentally determined, and the discharge speed Vo is calculated from equation (1).

The discharge speed is set to the predetermined value, and the discharge pressure is controlled to the predetermined value according to the discharge nozzle used in the experiment and the stock solution.

This operation will be explained in detail according to the flowchart shown in FIG.

When the operation starts, a command signal is issued to inject stock solution A into a predetermined stock solution tank 1 (step S1).
The control device 6 receives the temperature detection value ti from the temperature detector 16.
is read, and the viscosity μi corresponding to the temperature ti is calculated based on the viscosity-temperature table for the stock solution A that has already been set (steps S2 and S3). Next, the nozzle conditions (aperture di, length li) of the discharge nozzle 9-1 or 9-2 to be used, the predetermined value Vo of the discharge speed, and the discharge pressure correction constant Pk are read (steps S4, S5, S6). , the discharge pressure _P1 is calculated according to equation (2) (step S7).

P ₁ = Pk + 32Vo・μi・li/d _i ² ......(2) This discharge pressure P ₁ is output to the pressure regulator 7 and gas is sent from the air header 5' to the stock solution tank 1,
The pressure detection value Pi from the pressure detector 12 is read and the pressure regulator 7 is controlled so that Pi= _P1 (steps S8, S9, S10, S11). Due to the above,
The stock solution A discharged from the stock solution tank 1 has a predetermined value.
It will be discharged at a discharge speed of Vo. This operation is performed in the same manner for any stock solution tank 1.

Next, the injection method of the stock solution will be explained.

The purpose of this device is to automate blending operations where the blending ratio varies over an extremely wide range (1:2000 or more), such as in paint blending. By using different discharge nozzles accordingly, we aim to improve blending efficiency and precision.

This device basically detects the weight of the undiluted solution discharged into the receiver 11 and ends the dispensing of the undiluted solution when the detected weight reaches a predetermined amount. However, due to the following error factors, Accurate collection of stock solution is not possible.

(1) Residual amount error (Q _E1 ) This error is caused by the discharge nozzle 9-1 or 9-2.
The error due to the raw liquid between the tip of the liquid and the liquid surface of the receiver 11 is expressed as Q _E1 =ρ・π/4d ²・S (3).

However, S: Distance from the nozzle side end to the receiver liquid level (cm) ρ: Specific gravity of the stock solution (gr/ ^cm3 ) (2) Error due to the response of the weight detector, etc. (Q _E2 ) This error is due to the response of the balance. If the delay time due to these errors is te, it is expressed as Q _E2 =ρ・π/4d ²・V・te (4).

(3) Error due to dynamic load (Q _E3 ) This error is due to the dynamic load applied to the balance as the stock solution is continuously discharged.Q _E3 =ρ・π/4・d ² V(V+gt)/g…… (5).

However, g: Gravitational acceleration (cm/sec ² ) t: Falling time of the stock solution from the nozzle tip to the receiver liquid level (sec) Now, the total value of these error factors Q _E0 (hereinafter referred to as the discharge control value) is as follows. It can be obtained using the formula, Q _E0 = Q _E1 + Q _E2 −Q _E3 = ρπ/4d ² (S + V・te−V(V+gt)/g) ………(6) S, V, te, and t are constants. If given as ρ,
Discharge control according to d can be obtained. However, V is the predetermined discharge speed Vo. That is, Q _E0 =Kρd ² (7) where K: discharge control value constant The present invention basically employs the injection method as shown in FIG. 4 based on this discharge control value.

That is, by first injecting from the first discharge nozzle with a large diameter (A in Fig. 4), the injection time is shortened, and the weight detected by the balance is changed from the target injection amount to the first discharge nozzle. When the value obtained by subtracting the discharge control value is reached, the injection is shifted to the second discharge nozzle having a small diameter (B in FIG. 4) to improve the blending accuracy. Further, when the weight detected by the balance reaches a value obtained by subtracting the discharge control value of the second discharge nozzle from the target injection amount, injection is performed according to the microinjection method described later (C in Figure 4) This injection operation is illustrated in Figure 5. This will be explained in detail according to the flowchart.

When the operation starts, an injection command signal for stock solution A in a predetermined stock solution tank 1 is output (step S12).
The control device 6 controls the target injection amount Q and the allowable injection error amount Q _E
(step S13). Next, temperature sensor 1
Read the detected temperature ti from step 6 and select that temperature ti from the specific gravity-temperature table of stock solution A that has already been set.
Calculate the specific gravity Pi corresponding to (step S14,
S15). Next, read the nozzle conditions (aperture di) and discharge control value constant K of the first and second discharge nozzles, and read the discharge control values Q _E0 , Q' _E0 of the first and second discharge nozzles.
(Steps S16, S17, S18).

Target injection amount Q and discharge control value of the first discharge nozzle
Q _E0 (step S19), and if Q>Q _E0 , the first discharge valve is opened and discharge starts, and the balance 1
3, the injection amount Q _Di is detected and sequentially read (steps S20 and S21). When Q _Di reaches Q-Q _E0 , the first discharge valve is closed and discharge is interrupted (step
S22, S23). The injection amount Q _Si detected by the balance 13 when a predetermined period of time to has elapsed after the first discharge valve is closed is read (steps S24 and S25). Q-Q _Si is compared with the allowable injection error amount Q _E (step S26), and if Q-Q _Si ≦Q _E , the injection of stock solution A is completed.

If Q≦Q _E0 in step S19, the target injection amount Q and the discharge control value of the second discharge nozzle are
Q′ _E0 (step 27), if Q > Q′ _E0 and if Q − Q _Si > Q _E0 in step S26,
Furthermore, Q-Q _Si and Q _E0 are compared (step S28), and Q
-Q _Si >Q' _E0 , the second discharge valve is opened and discharge is started (resumed) (step S29).

The injection amount Q _Di detected by the balance 13 is sequentially read, and when Q _Di reaches Q- _Q'E0 , the second discharge valve is closed and the discharge is interrupted (steps S30, S31, S32).
Read the injection amount Q _Si detected by the balance 13 when a predetermined time t ₀ has passed after the second discharge valve is closed (step
S33, S34), compare Q-Q _Si and Q _E (step
S35), if Q-Q _Si ≦Q _E , the injection of stock solution A is completed.

If Q≦Q′ _E0 in step S27, if Q−Q _Si ≦Q′ _E0 in step S28, and if Q−Q _Si >Q _E in step S35, a microinjection command signal is output (step S36).

Next, the microinjection method will be explained.

This injection method is used when the target injection amount or allowable injection error is small, and basically controls the opening and closing of the discharge valve based on the relationship between the discharge weight and the discharge time.

That is, as shown in FIG. 6, first, one drop of the stock solution is dropped and its weight and ejection time are measured (6th
a) in the figure. From this, the ejection amount per unit time is calculated, and based on this, the time required to eject the target injection amount is determined, and ejection is performed for that time (b in FIG. 6). If the injection amount is still not within the allowable injection error after this operation, the operation of dropping one drop at a time is repeated (c, d, e in FIG. 6).

This injection operation will be explained in detail according to the flowchart of FIG.

When the microinjection command signal is output (step
S36), the control device 6 reads the microinjection discharge pressure △P and the detected pressure Pi from the pressure detector 12, and
The pressure regulator 7 is controlled so that = Pi (steps S37, S38, S39, S40, S41). After reading the injection amount Q _Si detected by the balance 13, the second discharge valve is opened for a predetermined time To, and after the predetermined time To has elapsed, the balance 1
Read the detected injection amount Q′ _Si according to step 3 (Step 3).
S42, S43, S44, S45, S46, S47). Q′ _Si and Q _Si are compared (step S48), and steps S43 to S48 are repeated until Q′ _Si >Q _Si .

If Q-Q' _Si ≦Q _E , the injection of stock solution A is completed (step S49).

If Q-Q′ _Si > Q _E , the discharge amount per unit time w
Calculate the discharge time _T1 from (step S50,
S51). α in the equation of step S51 is a margin rate that prevents the injection amount from exceeding the target injection amount, and is a constant of 1 or less. The second discharge valve is opened for T ₁ hour and after a predetermined time t ₀ has elapsed, the injection amount Q' _Si detected by the balance 13 is read (steps S52, S53, S54, S55, S56).
Compare Q-Q′ _Si and Q _E (step S57), and
If Q′ _Si ≦Q _E , injection of stock solution A is completed. Q-
If Q′ _Si > Q _E , open the second discharge valve for To time,
Repeat this operation until Q-Q′ _Si ≦Q _E (steps S58, S59, S60, S61, S62, S63), and Q-Q′ _Si
When ≦Q _E , injection of stock solution A is completed.

The above operation explanation is about discharging the stock solution A from one specific stock solution tank, but if the same operation is performed for two or more stock solution tanks storing different stock solutions or stock solutions, two or more stock solutions will be discharged at a predetermined weight ratio. Needless to say, it is possible to prepare more than one type of stock solution.

Effects As described above, by introducing the concept of discharge control value, the present invention automatically uses large-diameter and small-diameter discharge nozzles equipped with stock solution tanks according to the required injection amount and allowable injection error amount. So,
It is possible to shorten the injection time of the stock solution, and as mentioned above, by providing a micro-volume discharging means that controls the opening and closing time of the discharge valve, the micro-volume dispensing method can be automatically adjusted according to the required injection volume and allowable injection error amount. Since the switching is made, even if the required injection amount is extremely small or the required injection precision is extremely high, this can be handled.

Since the present invention has the above-mentioned features, if a plurality of stock solution tanks etc. are provided as necessary, it becomes perfectly suitable as an automatic compounding device for paints etc. with a wide variety of compounding prescriptions, streamlining the compounding work. can be significantly promoted.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing one embodiment of the present invention, Fig. 2 is a block diagram showing the configuration of an embodiment, and Fig. 3 is a flowchart showing the operation of adjusting the stock solution discharge speed to a predetermined value in the same embodiment. , FIG. 4 is a diagram showing the injection method in the present invention, FIG. 5 is a flowchart showing the injection operation of the above embodiment, FIG. 6 is a diagram showing the microinjection method in the present invention, and FIG. 7 is a diagram showing the above embodiment. 3 is a flowchart showing microinjection operation in FIG. 1... Raw solution tank, 8-1, 8-2... Discharge valve, 9-1, 9-2... Discharge nozzle, 11... Receiver, 7... Pressure regulator, 13... Weight detector, 1
6... Temperature detector, 20... Viscosity/specific gravity correction circuit, 21... Discharge pressure calculation circuit, 22... Comparison control circuit, 23... Comparison circuit, 24... Discharge control value calculation circuit, 25... Injection Remaining amount calculation circuit, 26...Discharge valve opening/closing control circuit, 27...Second discharge valve opening/closing time calculation circuit, 28...Timer.

Claims (1)

[Scope of Claims] 1. A stock solution tank containing stock solution, first and second discharge valves provided in a liquid feeding route branched from the stock solution tank, and a large body connected to each of the first and second discharge valves. A first discharge nozzle with a small diameter and a second discharge nozzle with a small diameter, a receiver that accommodates the stock solution to be injected, a pressure regulator that detects and adjusts the feeding pressure of the stock solution in the stock solution tank, and a weight that detects the weight of the stock solution to be injected. a detector; a temperature detector that detects the temperature of the stock solution; the temperature detected by the temperature detector is used as an input signal to correct the viscosity of the stock solution, and the discharge speed of the stock solution from the first and second discharge nozzles is set to a predetermined value; discharge pressure control means for outputting a signal to control the pressure regulator so that a discharge control value calculating means for calculating a discharge control value of the first and second discharge nozzles; and using the dynamic or static injection amount detected by the weight detector as an input signal, the injection amount and the target injection amount of the stock solution are calculated. a dynamic or static remaining injection amount calculating means for calculating a difference; a target injection amount of the stock solution or the dynamic or static injection remaining amount and the discharge control value; an allowable injection error amount of the stock solution and the static injection remaining amount; and a discharge valve control means for outputting a signal for controlling the opening and closing of the first and second discharge valves based on the comparison results, and a target injection amount of the stock solution is equal to or less than the discharge control value of the second discharge nozzle. or when the static injection remaining amount is larger than the allowable injection error amount of the stock solution and is less than or equal to the discharge control value of the second discharge nozzle as an input signal, the discharge pressure is adjusted to a predetermined pressure. output a signal to control the pressure regulator so that
A trace amount that measures the minimum unit discharge amount and discharge time of the stock solution discharged from the second discharge nozzle under the predetermined pressure, and outputs a signal for controlling the opening/closing time of the second discharge valve based on the measurement results. An automatic injection metering device comprising a discharge means.