JP2005152723A - Apparatus for mixing many different liquids and method for judging mixed state - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously judge in an early stage whether or not a liquid mixture of two or more different liquids has a correct mixing ratio. <P>SOLUTION: A gravimeter 35 is arranged on a liquid mixture hose 28 for connecting a mixer 26 to a spray gun 29 so that the specific gravity of the liquid mixture passing through the liquid mixture hose 28 is detected continuously. A controller judges the mixed state of the liquid mixture on the basis of the result as to whether or not the specific gravity of the liquid mixture detected by the gravimeter 35 is in an allowable range. When the controller judges that the mixed state is not good, the amount of a principal agent or a hardening agent to be supplied once is increased/decreased by changing an actuating signal of a solenoid valve 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multi-liquid mixing apparatus that mixes a plurality of liquids at a preset ratio, and more particularly to a multi-liquid mixing apparatus and a mixed state determination method suitable for a coating machine that discharges while mixing a main agent and a curing agent. .

  For example, in a two-component coating machine that discharges while mixing the main agent and curing agent at a predetermined ratio, after supplying the main agent and curing agent alternately to the premixer via separate paths, both solutions are supplied to the static mixer. A mixing device for mixing is provided. A spray gun is connected to the static mixer via a hose, and a mixed liquid as a paint is discharged from the spray gun.

In the mixing device, each liquid is preset by providing a flow meter and an opening / closing valve in the supply path from the supply source of each liquid to the premixer, and controlling the opening / closing operation of the opening / closing valve based on the measurement result of the flow meter. Is supplied to the premixer at a mixed ratio. In this case, the supply amount of the main agent and the curing agent is accurately controlled based on the time delay from when the control signal for the on-off valve is issued until the on-off valve actually operates, the relationship with the discharge operation of the spray gun, etc. It ’s difficult. Therefore, a method is used in which the supply amount of the other of the main agent and the curing agent is obtained by calculation based on the supply amount of one of the main agent and the curing agent, and the mixing ratio of both liquids is kept constant.
Japanese Patent No. 3144771

However, the above-described method is intended to keep the mixing ratio of the main agent and the curing agent constant by controlling the supply amount to the premixer, and whether or not the main agent and the curing agent are correctly mixed in the actual mixed liquid. It is not a judgment.
On the other hand, the mixed liquid discharged from the spray gun is sampled to perform color difference measurement, or the coated liquid mixture (that is, the coating film) is subjected to IR analysis (infrared spectroscopic analysis), and the main agent and There is a method for determining whether or not the curing agent is mixed at a preset mixing ratio.

  In the above method, the mixed state of the liquid mixture is determined after the spray gun is discharged and the coating is completed. In this case, since it takes time to determine the mixed state of the coated liquid mixture, it is not practical and costly because it is necessary to stop the coating line or check it in another process outside the coating line. It takes. Moreover, since it takes time to determine the mixed state, the determination result cannot be accurately fed back to control of the supply amount of the main agent or curing agent to the premixer.

Furthermore, in the above method, only the mixed state of a part of the mixed liquid discharged from the spray gun is determined, and the mixed state of the mixed liquid cannot be continuously determined.
The present invention has been made in view of the above circumstances, and an object of the present invention is to determine whether or not a mixed liquid of a plurality of different liquids is mixed at a correct mixing ratio early and continuously. It is to provide a mixing apparatus and a mixed state determination method.

  The multi-liquid mixing apparatus of the present invention includes a mixer for mixing a plurality of liquids having different specific gravities, a plurality of supply paths for independently supplying the plurality of liquids to the mixer, and each of the supply paths. An opening / closing valve provided, liquid supply means for controlling the opening / closing operation of the opening / closing valve to supply the plurality of liquids to the mixer at a preset mixing ratio, and formed in the mixer A discharge path for discharging the mixed liquid; a specific gravity detecting means for detecting the specific gravity of the mixed liquid provided in the discharge path; an input means for inputting the specific gravity of each of the plurality of liquids; The calculation means for calculating the specific gravity of the liquid mixture based on a preset mixing ratio, the specific gravity detection value of the liquid mixture by the specific gravity detection means, and the specific gravity calculation value of the liquid mixture by the calculation means are compared to determine the mixing ratio. Liquid mixing It is provided with a determination means for determining status.

The mixed state determination method of the present invention includes a step of calculating the specific gravity of a mixed liquid based on the specific gravity of each of a plurality of liquids and a preset mixing ratio, and a step of detecting the specific gravity of the mixed liquid formed by the multi-liquid mixing apparatus. And a step of determining a mixed state of the liquid mixture by comparing the calculated specific gravity with the detected specific gravity.
The specific gravity of the liquid mixture calculated in the calculation means or the calculation step is an ideal specific gravity of the liquid mixture obtained when a plurality of liquids are correctly mixed at a preset mixing ratio, in other words, a target value of specific gravity. is there. On the other hand, the specific gravity detecting means or the step of detecting specific gravity detects the specific gravity of the actual liquid mixture. That is, the main feature of the present invention is to determine the mixed state of the mixed liquid by comparing the specific gravity of the actual mixed liquid with the target value.

  The multi-liquid mixing apparatus and the mixed state determination method of the present invention continuously detect the specific gravity of the mixed liquid flowing through the discharge path for discharging the mixed liquid mixed by the mixer, and detect the specific gravity and target value of the mixed liquid. Therefore, the mixed state of the liquid mixture can be determined early and continuously.

  A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram schematically showing a two-component mixing type coating machine 1 (corresponding to a multi-component mixing device) according to this embodiment. The coating machine 1 according to the present embodiment includes three pressure feed pumps 2 to 4 constituting a main agent supply source, one pressure feed pump 5 constituting a curing agent supply source, and a pressure feed pump 6 for a cleaning thinner. . Although not shown, the pumps 2 to 6 are connected to tanks for storing a main agent, a curing agent, and a cleaning thinner, respectively. The main agent and the curing agent used in the coating machine 1 are premised on different specific gravities.

  Further, the pressure pumps 2 to 6 are all connected to the manifold 7. The manifold 7 is internally divided into a main agent flow path 8 and a hardener flow path 9. On / off valves 10 to 13 are respectively provided at the four inlets of the main agent flow path 8, and the main pumping pumps 2 to 4 are connected to the on / off valves 10 to 12. In addition, on / off valves 14 and 15 are respectively provided at the two inlets of the curing agent passage 9, and the on-off valve 14 is connected to the pressure-feed pump 5 for the curing agent. A pressure pump 6 of the cleaning thinner is connected to the on-off valves 13 and 15.

The on-off valves 10 to 15 are pneumatically driven for explosion-proof reasons. Pressurized air for driving the on-off valves 10 to 15 is supplied from a pressurized air supply source 16 via an electromagnetic valve 17.
An outlet of the main agent flow path 8 of the manifold 7 is connected to a premixer 19 via a main agent passage 18 (corresponding to a supply path). The outlet of the hardener flow path 9 of the manifold 7 is connected to the premixer 19 via a hardener path 20 (corresponding to a supply path). In the middle of the main agent passage 18 and the hardener passage 20, flow meters 21, 22 and check valves 23, 24 are provided, respectively.

The premixer 19 has a double cylindrical structure having a distribution pipe inside the mixing chamber, similar to the premixer described in, for example, Japanese Patent Laid-Open No. 11-347460. The main agent passage 18 is connected to a mixing chamber, and the curing agent passage 20 is connected to a distribution pipe.
When the main agent and the curing agent are alternately supplied to the mixing chamber and the distribution pipe of the premixer 19 so as to have a predetermined mixing ratio, both liquids are discharged from the mixing chamber outlet in a roughly mixed state. A static mixer 25 is connected to the mixing chamber outlet, and the main agent and the curing agent are mixed almost uniformly in the static mixer 25. The premixer 19 and the static mixer 25 constitute a mixer 26.

  A drain valve 27 is connected to the discharge port of the static mixer 25. A spray gun 29 is connected to one outlet of the drain valve 27 via a mixed liquid hose 28 (corresponding to a discharge path). A hydrometer 35 (corresponding to specific gravity detecting means) is provided in the middle of the mixing hose 28. Further, a drain hose 30 is connected to another outlet portion of the drain valve 27, and a drainage tank 31 is disposed at the tip of the drain hose 30.

The drain valve 27 is a pneumatically driven type similar to the on-off valves 10 to 15. Pressurized air for driving the drain valve 27 is supplied via a solenoid valve from a pressurized air supply source (not shown).
FIG. 2 schematically shows an electrical configuration of the coating machine 1 according to the present embodiment, and the control device 32 is configured mainly with a microcomputer and controls various operations of the coating machine 1. Various data such as the control program, the capacity of the premixer 19 and the mixer 26 are stored in advance.

  The control device 32 is connected to flow meters 21 and 22 and a specific gravity meter 35. The control device 32 is connected to the electromagnetic valve 17, the operation key 33, and the display 34. The flow meters 21 and 22 are constituted by, for example, volumetric flow meters that generate one pulse signal by measuring a constant flow rate. The signal is configured to be supplied to the control device 32. The hydrometer 35 is composed of, for example, a Coriolis type mass flow meter, and outputs an electric signal corresponding to the specific gravity of the liquid mixture passing through the liquid mixture hose 28. Signals supplied from the flow meters 21 and 22 and the hydrometer 35 are converted into voltage signals by the control device 32 and then input to the microcomputer.

  The operation keys 33 and the indicator 34 are provided on an operation panel (not shown) provided in the coating machine 1. The operation key 33 is used to input the specific gravity of the main agent and the curing agent, and to set the mixing ratio of the main agent and the curing agent, the color change of the paint (selection of the main agent), and the like. Therefore, the operation key 33 functions as input means. The indicator 34 displays the operation status of the coating machine 1 and reports an abnormality.

The control device 32 controls the drive of the display 34 and the electromagnetic valve 17 in accordance with a control program stored in advance based on signals from the flow meters 21 and 22 and the hydrometer 35, an operation signal of the operation key 33, and the like. It is supposed to be.
In this embodiment, the control device 32 constitutes calculation means and determination means. The control device 32 and the electromagnetic valve 17 constitute liquid supply means.

  Next, the operation of the above configuration will be described. When the operation key 33 is operated and the specific gravity of the main agent and the curing agent, the mixing ratio of the main agent and the curing agent, and the like are set, the control device 32 performs one supply based on the set mixing ratio, the capacity of the premixer 19, and the like. The supply amount of the main agent and the curing agent in the cycle is obtained by calculation. The supply amounts of the main agent and the curing agent in one supply cycle can be changed as appropriate.

Further, the control device 32 obtains the specific gravity of the liquid mixture (hereinafter referred to as a target value) by calculation based on the specific gravity of the main agent and the curing agent and the mixing ratio of both, and sets an allowable range of the specific gravity of the liquid mixture.
In this embodiment, since the main agent and the curing agent are alternately supplied to the premixer 19, the mixed solution passing through the mixed solution hose 28 alternately appears in a state where the mixing ratio of the main agent exceeds the set ratio and a state where it falls below the set ratio. . And, for example, if the specific gravity of the main agent is larger than the specific gravity of the curing agent, the specific gravity of the mixed liquid exceeds the target value in a state where the ratio of the main agent in the mixed liquid exceeds the set ratio, and the ratio of the main agent in the mixed liquid In a state where the ratio is lower than the set ratio, the specific gravity of the mixed liquid is lower than the target value. That is, the specific gravity of the mixed liquid varies for each supply cycle. Moreover, the amount in which the specific gravity of the mixed liquid exceeds and falls below the target value varies depending on the amount of supply of the main agent and the curing agent at one time and the specific gravity of the main agent and the curing agent.

  For example, FIG. 3 shows how the specific gravity of the mixed solution varies with respect to the target value (straight line A) of the specific gravity of the mixed solution. The horizontal axis in FIG. 3 represents time, and the vertical axis represents the voltage value corresponding to the specific gravity. The straight line A represents the target value, and the curve B represents the variation in specific gravity. The upper limit value (straight line UL) and the lower limit value (straight line LL) of the allowable range are set in consideration of such variation in specific gravity. The upper limit value and the lower limit value are calculated as follows.

When the set mixing ratio of the main agent and the curing agent is “γ: 1” (γ ≧ 1), the upper limit of the specific gravity of the mixed liquid when the mixing ratio is “(γ + α): 1” (α> 0) And the specific gravity of the mixing ratio when the mixing ratio is “(γ−α): 1” is the lower limit. The value of α is set based on a single supply amount of the main agent and the curing agent, the specific gravity of the main agent and the curing agent, the accuracy of the mixed liquid, and the like.
When the start of the painting operation is instructed, the electromagnetic valve 17 is operated based on a command signal from the control device 32, and any one of the on-off valves 10 to 12 and the on-off valve 14 are alternately opened for a predetermined time. Thereby, the liquid supply operation is executed. At this time, the control device 32 detects the supply amount of the main agent to the premixer 19 based on the pulse signal input from the flow meter 21, and supplies the curing agent to the premixer 19 based on the pulse signal input from the flow meter 22. Detect the amount. Based on these detection results, an operation command signal for the electromagnetic valve 17 is output at a predetermined timing.

  As a result, the main agent and the curing agent are sequentially supplied to the manifold 7 in a predetermined supply amount, respectively, and proceed to the premixer 19 through the main agent passage 18 and the curing agent passage 20. The main agent and the curing agent supplied to the premixer 19 are supplied to the static mixer 25 in a mixed state and are completely mixed, and the spray gun 29 is mixed with the spray hose 28 according to the opening / closing operation of the discharge valve of the spray gun 29. It is discharged from the gun 29.

  The control device 32 is continuously supplied with a specific gravity detection signal from the hydrometer 35 in the mixed liquid hose 28. Then, the control device 32 detects the specific gravity of the liquid mixture based on the given detection signal, and compares the specific gravity detection value with the upper limit value and the lower limit value of the allowable range. In addition, when the specific gravity detection value is out of the allowable range, the control device 32 determines that the mixing is poor and adjusts the opening time of any of the on-off valves 10 to 12 or the on-off valve 14 to adjust the main agent. Alternatively, the supply amount of the curing agent is increased or decreased.

  Specifically, when the specific gravity of the main agent is larger than that of the curing agent, and the ratio of the one supply amount of the main agent to one supply amount of the curing agent exceeds the set ratio, The specific gravity detection data is as shown by a curve B1 in FIG. As described above, when the one supply amount with the larger specific gravity of the two liquids to be mixed exceeds the amount corresponding to the set ratio, there is a state in which the specific gravity of the mixed liquid exceeds the upper limit of the allowable range. Therefore, when a detection result such as the curve A1 is obtained, the control device 32 changes the operation command signal of the electromagnetic valve 17 to reduce the one-time supply amount of the liquid having the larger specific gravity (in this case, the main agent). Let

  On the other hand, although not illustrated, when the ratio of the one supply amount of the curing agent to the one supply amount of the main agent exceeds the set ratio, there is a state where the specific gravity of the mixed liquid is below the lower limit value of the allowable range. . Therefore, when such a detection result is obtained, the control device 32 changes the operation command signal of the electromagnetic valve 17 to change the supply amount of the liquid having a smaller specific gravity (in this case, the curing agent). Decrease.

  FIG. 4 shows an example of the case where both the state where the specific gravity of the liquid mixture exceeds and falls below the upper limit of the allowable range. In FIG. 4, straight lines A, UL, and LL indicate a target value, an upper limit value, and a lower limit value, respectively. A curve B ′ represents a variation in specific gravity with respect to the target value, and a curve B2 represents specific gravity detection data of the mixed liquid. As shown in FIG. 4, the center of the curve B2 substantially coincides with the target value, but there is a state where the vertical fluctuation is large and exceeds both the upper limit value and the lower limit value. Such a result shows that the ratio of the one supply amount of the main agent to the one supply amount of the curing agent is substantially the same as the set ratio, but the total amount of the one supply amount of the main agent and the curing agent is acceptable. Seen when out of range. Therefore, when such detection data is obtained, the control device 32 changes the operation command signal of the electromagnetic valve 17 to reduce the supply amount of the main agent and the curing agent each time.

Thus, in the present embodiment, the specific gravity of the mixed liquid passing through the mixed liquid hose 28 is continuously detected by the hydrometer 35, and the mixed state of the mixed liquid is determined based on whether or not the detected value is within an allowable range. Is determined. Therefore, the mixed state of the liquid mixture can be continuously and accurately determined before being discharged from the spray gun 29.
Further, the control device 32 controls the electromagnetic valve 17 based on the determination result of the mixed state of the mixed liquid, and adjusts the supply amount of the main agent and the curing agent once. Therefore, it is possible to prevent the mixed liquid having a wrong mixing ratio from being discharged from the spray gun 29 and used for coating, or the coating using the mixed liquid having the wrong mixing ratio to be continued.

  FIG. 5 shows a second embodiment of the present invention, and the differences from the first embodiment will be described. In the second embodiment, a hydrometer 41 for detecting the specific gravity of the main agent is provided in the middle of the main agent passage 18, for example, between the flow meter 21 and the check valve 23. Further, a hydrometer 42 for detecting the specific gravity of the hardener is provided in the middle of the hardener passage 20, for example, between the flow meter 22 and the check valve 24. The specific gravity meters 41 and 42 correspond to specific gravity detection means before mixing. The configuration other than the above is the same as that of the first embodiment.

The outputs of the hydrometers 41 and 42 are given to the control device 32. The control device 32 detects and sets the specific gravity of the main agent and the curing agent based on the outputs of the specific gravity meters 41 and 42. That is, in this embodiment, the specific gravity of the main agent and the curing agent is automatically set.
The specific gravity of the main agent or curing agent is described on a label or the like attached to the main agent or curing agent storage tank. Therefore, in the configuration of the first embodiment described above, the operator inputs the specific gravity of the main agent and the curing agent by looking at the specific gravity described on the label or the like. However, when the specific gravity described on the label or the like is slightly different from the actual specific gravity of the main agent and the curing agent, the target value of the specific gravity of the mixed liquid cannot be accurately calculated.

On the other hand, in this embodiment, the specific gravity of the main agent and the curing agent is detected by the specific gravity meters 41 and 42. For this reason, the target value of the specific gravity of the liquid mixture can be accurately calculated, and the quality of the mixed state of the liquid mixture can be accurately determined.
The present invention is not limited to the above-described embodiments, and for example, the following modifications are possible.

The control device 32 may determine the quality of the mixed state based on the difference between the detected value of the specific gravity of the mixed liquid and the target value.
In the above example, when the detected value of the specific gravity of the mixed solution exceeds the upper limit value, the supply amount of one of the main agent and the curing agent having the larger specific gravity was decreased, but the smaller specific gravity was 1 The supply amount at one time may be increased, or the one supply amount with a larger specific gravity may be decreased and the one supply amount with a smaller specific gravity may be increased.

In addition, when the specific gravity is below the lower limit, it is configured to decrease the one supply amount with the smaller specific gravity, but the one supply amount with the larger specific gravity may be increased, and the one with the larger specific gravity. It is also possible to increase the one-time supply amount and decrease the one-time supply amount with a smaller specific gravity.
The present invention can also be applied to a two-component mixing device in which the main agent and the curing agent are supplied to the mixing device at the same time, and a mixing device that mixes three or more kinds of liquids. Further, the mixed liquid formed by mixing a plurality of types of liquids may be a paint, an adhesive, a chemical, a food, or the like, and the present invention can be applied to a multi-liquid mixing apparatus used in various fields.

The 1st Example of this invention is shown, and the figure which shows schematically the whole structure of a two-component mixing type coating machine Block diagram showing electrical configuration The figure for demonstrating the determination method of a mixing state (the 1) The figure for demonstrating the determination method of a mixing state (the 2) FIG. 1 equivalent view showing a second embodiment of the present invention.

Explanation of symbols

In the drawings, 1 is a two-component mixing type coating machine (multi-component mixing device), 10 to 15 are on-off valves, 17 is an electromagnetic valve (liquid supply means), 18 is a main agent passage (supply passage), 19 is a premixer, and 20 is Curing agent passage (supply path), 21 and 22 are flow meters, 25 is a static mixer, 26 is a mixer, 28 is a mixed liquid hose (discharge path), and 32 is a control device (liquid supply means, calculation means, determination means). , 33 are operation keys (input means), 35 is a hydrometer (specific gravity detecting means), and 41 and 42 are hydrometers (pre-mixing specific gravity detecting means).

Claims (5)

A mixer for mixing a plurality of liquids having different specific gravities,
A plurality of supply paths for independently supplying the plurality of liquids to the mixer;
An on-off valve provided in each of the supply paths;
Liquid supply means for supplying the plurality of liquids to the mixer so as to have a preset mixing ratio by controlling the opening and closing operation of the on-off valve;
A discharge path for discharging the liquid mixture formed in the mixer;
Specific gravity detecting means provided in the discharge path for detecting the specific gravity of the mixed liquid;
Input means for inputting the specific gravity of each of the plurality of liquids;
A calculating means for calculating the specific gravity of the liquid mixture based on the specific gravity of each input liquid and a preset mixing ratio;
A multi-liquid mixing apparatus comprising: a determination unit that determines a mixed state of the mixed liquid by comparing a specific gravity detection value of the mixed liquid by the specific gravity detection unit and a specific gravity calculation value of the mixed liquid by the calculation unit.   2. The multi-liquid mixing apparatus according to claim 1, wherein the input means includes a plurality of pre-mixing specific gravity detecting means provided in each of the plurality of supply paths to detect the specific gravity of each liquid.   3. The multi-liquid mixing apparatus according to claim 1, wherein the determination unit determines a mixed state of the liquid mixture based on whether or not the specific gravity detection value is within a specific gravity range including the specific gravity calculation value.   4. The multi-liquid mixing apparatus according to claim 1, wherein the liquid supply means adjusts the opening / closing operation of the on-off valve based on the determination result of the determination means. In a mixed state determination method for determining a mixed state of a mixed liquid in a multi-liquid mixing apparatus that mixes a plurality of liquids having different specific gravities at a preset mixing ratio,
Calculating the specific gravity of the liquid mixture based on the specific gravity of each of the plurality of liquids and a preset mixing ratio;
Detecting the specific gravity of the liquid mixture formed by the multi-liquid mixing device;
And a step of determining the mixed state of the mixed liquid by comparing the calculated specific gravity with the detected specific gravity.

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