JP3144771B2 - Multi-liquid mixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-liquid mixing method for mixing multi-liquids at a fixed ratio as used in a two-liquid coating method comprising a main liquid and a curing liquid.

[0002]

2. Description of the Related Art When multiple liquids are mixed at a fixed ratio, if the respective liquids are accurately measured and supplied to a mixer, they can be mixed at an accurate ratio, but for example, they are widely used. When controlling the supply and stop of a flammable liquid such as paint, an electromagnetic on-off valve cannot be used for explosion-proof reasons, and an electric signal is converted to a pneumatic signal using an electropneumatic converter. The supply and stop of liquid must be controlled by a pneumatically driven on-off valve, but since air is compressible, there is a delay between when a control signal is issued and when the on-off valve actually operates. And accurate quantitative control is difficult.

For this reason, as described in Japanese Patent Application Laid-Open No. 6-294677, one liquid is supplied, and based on this supply amount, the supply amount of the other liquid is constantly calculated to thereby determine the mixing ratio. Control to make it constant was performed.

[0004]

However, in such a control method, it is difficult to keep the mixing ratio and the mixing amount in one cycle accurately and exactly, and in the conventional method, the discharge and stop of the mixed liquid are repeated. In the case of intermittent ejection, there is a problem that an error occurs in the mixing ratio due to the stoppage of the ejection of the mixed liquid between the time when the supply stop signal is issued for one liquid and the time when the supply is stopped.

[0005]

Means for Solving the Problems, Functions and Effects As means for solving such problems, the invention of claim 1 is characterized in that the supply control on-off valve is opened and closed so that the multiple liquids have a constant ratio. In the multi-liquid mixing method in which the supplied amounts are sequentially supplied to the mixer for mixing, a method of storing the amount to be supplied once for each liquid, and a supply stop signal for each liquid are issued. And the method of measuring and storing in advance the time from when the supply control on / off valve is actually closed to the time when the supply control on / off valve is closed, and a pulse corresponding to a constant flow rate emitted from a positive displacement type flow meter provided in the flow path for each liquid. The method of storing the signal period, the number of pulse signals corresponding to the amount to be supplied at once for each liquid, and the time from when the supply stop signal is issued until the supply control on / off valve is actually closed Calculate the number of corresponding pulse signals From the method of integrating the number of pulse signals generated after the supply control on / off valve is opened for each liquid, and the number of pulse signals corresponding to the amount to be supplied at one time for each liquid. A method of calculating a calculated value by subtracting the integrated value of the number of pulse signals generated after the supply control on / off valve is opened, and a method of obtaining the calculated value for each liquid after the supply stop signal is issued and the supply control on / off valve Issuing a supply stop signal when the number of pulse signals corresponding to the time until the valve closes is closed, wherein each method is executed by the control device, and the operation of the supply control valve is performed. Since the stop signal is issued in anticipation of the delay time, an accurate amount of liquid can be supplied, and the mixing ratio can be kept constant. The invention of claim 2 is the invention of claim 1 , Open the supply control on / off valve for each liquid A method in which the number of pulse signals corresponding to each time is determined in advance, and a discharge control provided at the end of the mixer while the supply control on / off valve is opened after the supply stop signal is issued for one liquid. A method of calculating the remaining number of pulse signals corresponding to the remaining amount of the original supply amount when the on-off valve is closed, and opening the supply control on-off valve corresponding to the remaining number of the pulse signal for the one liquid A method of selecting a time, and a method of opening the one liquid supply control on / off valve for the opening time of the supply control on / off valve after the discharge control on / off valve is restarted, each method being executed by the control device. In the case where the discharge control on / off valve is closed before the valve is actually closed after the supply control on / off valve is closed, the remaining amount is supplied next time. Therefore, the mixing ratio can be There is an effect that can be kept constant.

According to a third aspect of the present invention, there is provided a method according to the second aspect, wherein the number of pulse signals corresponding to each opening time of the supply control on / off valve is determined in advance for each liquid. The invention according to claim 4, wherein the number of pulse signals corresponding to each opening time of the supply control on / off valve is previously measured and stored, so that an accurate amount of liquid can be replenished. According to the third aspect of the present invention, the number of pulse signals corresponding to each opening time of the supply control on / off valve is measured and stored in advance according to the change in the flow rate for each liquid. In the invention according to the second aspect, the number of pulse signals corresponding to each opening time of the supply control on-off valve is determined in advance for each liquid. Method is to start the supply control for each liquid. The number of pulse signals corresponding to each valve opening time is measured in advance at a constant flow rate, and the number of pulse signals at the actual flow rate is calculated and stored based on the ratio of the flow rates. Therefore, replenishment of the liquid when the flow velocity changes can be performed accurately only by measuring the constant flow velocity.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a pressurized supply source of a first liquid,
2 is a pressurized supply source of the second liquid, 3 is a controller, 4 is a flow meter of the first liquid, 5 is a flow meter of the second liquid, 6 is a supply control opening / closing valve of the first liquid, and 7 is a second liquid. Is a supply control opening / closing valve, 8 is a mixer, 9 is a discharge control opening / closing valve, and the flow meters 4 and 5 are positive displacement and transmit one pulse signal every time a constant flow rate is measured.
It is input to the control device 3.

The supply control on-off valves 6 and 7 are alternately opened and closed with a certain delay time based on an on-off signal issued from the control device 3 to supply the first liquid and the second liquid to the mixer 8 for mixing. The discharge control opening / closing valve 9 is connected to a spray gun (not shown).

First, when the discharge control on-off valve 9 is continuously opened for a relatively long time, the control device 3 stores the amount to be supplied once for each liquid, A method of measuring and storing in advance the time from when a supply stop signal is issued to when the supply control on / off valves 6 and 7 are closed, a positive displacement type flow meter provided in the flow path for each liquid A method for storing the period of the pulse signal corresponding to a constant flow rate issued from 6, 7; the number of pulse signals corresponding to the amount to be supplied at a time for each liquid; To calculate the number of pulse signals corresponding to the time until the supply control on / off valves 6 and 7 close, and integrate the number of pulse signals issued after the supply control on / off valves 6 and 7 open for each liquid The amount of liquid to be supplied at one time for each liquid. A method of obtaining a calculated value by subtracting the integrated value of the number of pulse signals generated after the supply control on / off valves 6 and 7 are opened from the number of the supply signals, a supply stop signal is generated for each liquid. And a method of issuing a supply stop signal when the number of pulse signals corresponding to the time until the supply control on / off valves 6 and 7 are actually closed is executed to perform appropriate mixing. Is performed before the mixing is performed, and the present invention is not limited to being performed in this order.

In the above method, the method of storing the period of the pulse signal corresponding to the constant flow rate emitted from the flow meter includes a method of directly inputting and storing and a method of actually measuring and inputting.

Next, when the discharge control on-off valve 9 is intermittently opened and closed in a relatively short time, the discharge control on-off valve 6, 7 is discharged until the valve is actually closed after the closing signal is transmitted. In the above-described method, the number of pulse signals corresponding to each liquid-opening time of the supply control on-off valves 6 and 7 is determined in advance in the above-described method since the control on-off valve 9 repeatedly closes and the mixing ratio error increases. When the discharge control on / off valve 9 provided at the end of the mixer 8 is closed while the supply control on / off valves 6 and 7 are open after the supply stop signal is issued for one liquid, A method of calculating the remaining number of pulse signals corresponding to the remaining amount of the original supply amount, and a method of selecting the opening time of the supply control opening / closing valves 6 and 7 corresponding to the remaining number of the pulse signals for one liquid. Supply control after the discharge control on-off valve 9 is restarted. A method of opening the supply control on / off valves 6 and 7 for the one liquid only for the opening time of the on / off valves 6 and 7. In the case where the discharge control on-off valve 9 is closed before the valve is actually closed after the transmission of the valve closing signals 6 and 7, the remaining amount is supplied next time. Can be kept.

In the case of the above-mentioned intermittent discharge, the method of previously determining the number of pulse signals corresponding to each opening time of the supply control on / off valves 6 and 7 for each liquid is as follows. It is executed by previously measuring and storing the number of pulse signals corresponding to each of the valve opening times 6 and 7,
Further, the number of the pulse signals is executed by previously measuring and storing the number according to the change in the flow velocity.
The method of determining in advance the number of pulse signals corresponding to each opening time of the supply control on-off valves 6 and 7 for each liquid corresponds to each opening time of the supply control on-off valves 6 and 7 for each liquid. The number of pulse signals to be performed may be measured in advance at a constant flow rate, and the number of pulse signals at the actual flow rate may be calculated and stored based on the ratio of the flow rates.

[Brief description of the drawings]

FIG. 1 is a block diagram of a multi-liquid mixing method of the present invention.

[Explanation of symbols]

 1, 2: pressurized supply source 3: control device 4, 5: flow meter 6, 7: supply control on / off valve 8: mixer 9: discharge control on / off valve

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-294674 (JP, A) JP-A-7-280631 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01F 3 / 08,15 / 04 G01F 13/00

Claims (4)

(57) [Claims] 1. A multi-liquid mixing method in which multi-liquids are supplied to a mixer by a predetermined amount in sequence by opening and closing a supply control on-off valve so as to have a constant ratio, and are mixed. A method of storing the amount to be supplied each time, a method of measuring and storing in advance the time from when a supply stop signal is issued for each liquid to when the supply control on-off valve is actually closed, and A method of storing a cycle of a pulse signal corresponding to a constant flow rate emitted from a positive displacement flow meter provided in the flow path for each liquid, and a method of storing a pulse signal corresponding to an amount to be supplied at a time for each liquid. A method for calculating the number of pulses and the number of pulse signals corresponding to the time from when the supply stop signal is issued until the supply control on / off valve is actually closed, and for each liquid, issued after the supply control on / off valve is opened. Method of integrating the number of pulse signals A method of calculating a calculation value by subtracting the integrated value of the number of pulse signals generated after the supply control on / off valve is opened from the number of pulse signals corresponding to the amount to be supplied at one time for each liquid; A method for issuing a supply stop signal when the calculated value matches the number of pulse signals corresponding to the time from when the supply stop signal is issued to when the supply control opening / closing valve is actually closed, for each liquid, Pulse corresponding to each opening time of the supply control on-off valve
The number of signals is determined in advance , and the supply control is performed after the supply stop signal is issued for one liquid.
Provided before the mixer while the on-off valve is open
When the discharge control on-off valve closes, the original supply amount remains
A method for calculating the number of remaining pulse signals corresponding to the number of remaining pulse signals for one liquid.
A method for selecting a valve opening time of a supply control on-off valve and a supply control on-off valve after the discharge control on-off valve is restarted
For opening one liquid supply control on / off valve for the valve opening time
And Law, made, multi-liquid mixing method of the respective method is performed by the control device. 2. The method according to claim 2 , wherein the supply control on / off valve is opened for each liquid.
How to predetermine the number of corresponding pulse signals
Correspond to the opening time of the supply control on / off valve for each liquid.
By measuring and storing the number of
The multi-liquid mixing method according to claim 1, wherein the method is performed. 3. Each supply time of the supply control on / off valve for each liquid.
Predetermine the number of corresponding pulse signals according to changes in flow velocity.
The multi-liquid mixing method according to claim 2, wherein the multi-liquid mixing method is measured and stored. 4. Each supply time of the supply control on / off valve for each liquid
How to predetermine the number of corresponding pulse signals
Correspond to the opening time of the supply control on / off valve for each liquid.
Measure the number of pulse signals at a constant flow rate in advance.
The number of pulse signals at the actual flow velocity
Claims that are executed by calculating and storing
2. The multi-liquid mixing method according to 1.