JPH0624656B2 - Paint discharge control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Field of Industrial Application >> The present invention relates to an improvement of a paint discharge amount control device.

<< Prior Art >> In recent years, painting of automobile bodies and the like has generally been performed by automatic painting machines. FIG. 4 shows an example of this type of automatic coating machine. This coating machine is an automatic coating machine main body processing arithmetic unit 1, a microcomputer 2, a coating nozzle 3, a mass flow meter 4, an air operation regulator. (Hereinafter referred to as air operation) 9, electro-pneumatic conversion device 10, color change valve group 14, regulator group 15, paint supply pipe 16, cleaning thinner supply pipe 1
7, a cleaning air supply pipe 18, a paint ON / OFF valve 20, a paint supply passage 21, and the like.
The discharge amount of the paint is basically controlled by the electro-pneumatic conversion device 10 and the air ope 9 based on the discharge amount signal input from the automatic coating machine main processing unit 1 to the microcomputer 2. However, it is difficult to control the discharge rate accurately with just this, so a mass flow meter (for example, Coriolis flow meter)
The detection result of No. 4 is input to the microcomputer 2, this detection result is compared with the set discharge amount, and a correction value is given to the electro-pneumatic conversion device 10 to correct the flow rate difference.

The conventional automatic coating machine is configured as described above,
The following problems have been pointed out for this coating machine.

<< Problems to be Solved by the Invention >> That is, since the coating machine described above has only one paint supply passage 21, when changing the coating color, after closing the color change valves 14A ... 14N, the air valve 14P and the thinner valve are closed. It is necessary to open 140 to blow away the residual paint in the paint supply passage 21 from the nozzle 3 to the outside (this is called push-out). However, the amount of the residual paint blown out is enormous in total annually, and in particular, under the situation where the high-grade paint is often used recently, a considerable waste of cost occurs.

Therefore, as a method of effectively utilizing the residual paint, it has been proposed to close the color change valve just before the end of painting and use the push-out paint for subsequent painting. However, in this method, a so-called fictitious paint flow rate is detected by the microcomputer 2 and the mass flow meter 4, so that flow rate control of the push-out paint is disturbed. That is, when the thinner flows to the mass flowmeter 4 as the pushout progresses, the mass flowmeter 4 detects the mass flow rate of the thinner and inputs the detection result to the microcomputer 2 as it is. No. 2 judges the paint flow rate is too small without correcting the density difference between thinner and paint, and based on this erroneous judgment,
This gives an incorrect correction value to the sky conversion device 10. As a result, the coating flow rate from the nozzle 3 becomes excessive and the coating thickness of the automobile body becomes uneven,
There is a problem with coating quality.

The present invention has been devised to effectively solve the above-mentioned problems, and the purpose thereof is to achieve appropriate or uniform coating film thickness by improving the accuracy of flow control of push-out paint. To do.

<< Means for Solving the Problems >> The present invention for solving the above-described problems includes a paint regulator and a paint mass flowmeter in a paint supply passage connecting a paint nozzle and a color change valve group. In a paint discharge amount control device arranged to control the paint discharge amount by operating the paint regulator based on the detection result of the mass flowmeter, a cleaning liquid valve in the color change valve group A cleaning liquid regulator and a cleaning liquid mass flowmeter are respectively installed in the connected cleaning liquid supply passages, and when the remaining paint in the paint supply passage is extruded with the cleaning liquid and the coating is to be continued just before the end of the coating, the above-mentioned paint is used. From the operation of the paint regulator based on the detection result of the mass flowmeter for cleaning, The discharge amount of the residual paint is controlled by switching to the operation of the cleaning liquid regulator and controlling the flow rate of the cleaning liquid.

<Operation> In the paint discharge amount control device configured as described above,
The paint flow rate is controlled by the paint regulator and paint mass flowmeter installed in the paint supply passage until the push-out (extrusion of the paint by the cleaning liquid) occurs just after the end of coating, and the cleaning liquid is supplied after the push-out. The flow rate of the cleaning liquid and hence the residual paint flow rate is controlled by the cleaning liquid regulator and the mass flow meter for the cleaning liquid that are installed in the passage. Disturbance in flow control of the paint is prevented, and the quality of the paint surface painted by pushout is improved.

Example An example of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a paint discharge amount control device according to the present invention. This device is different from the conventional one in that the thinner air supply passage 22 has a thinner air operation 9Y and a thinner mass flow rate. This is the point where a total of 4Y are arranged. Since the configuration of the other portions is the same as the conventional one, the same portions as those in FIG. 4 are denoted by the same reference numerals and the description thereof will be omitted. The thinner air operation 9Y is controlled by an air signal output from the electro-pneumatic conversion device 10Y. On the other hand, the thinner mass flowmeter 4Y inputs the detection result to the microcomputer 2, and the microcomputer 2 compares the preset flow rate with the above detection result and performs electro-pneumatic conversion to correct the difference in flow rate. A correction value is given to the device 10Y. A paint air operation 9X and a paint mass flowmeter 4X are arranged in the paint supply passage 21 as in the conventional case, and the paint air operation 9X is controlled by an air signal output from the electro-pneumatic converter 10X. It's
In the following, the construction on the paint supply passage 21 side and various physical property values and the like will be suffixed with X, and the construction and various physical property values on the thinner supply passage 22 side will be suffixed with Y to distinguish them.

Next, the processing contents of the microcomputer 2 will be described based on the flowcharts of FIGS. 2 and 3. First, in step S1 in FIG. 2, it is determined whether or not the truck on which the vehicle body is mounted has passed through the coating line entrance. Next, in steps S2 to S3, the color to be painted on the car body and the vehicle type are read, and the paint color parameter i
And the vehicle type parameter j are set. In step S5, the number F (j) of coating areas (areas such as the hood, roof, and deck) is set based on the vehicle type parameter j, and subsequently in step S6, the coating density Dsp (i) is set based on the coating color parameter i. To be done. The processing flow up to this point is exactly the same as the conventional one.

Next, in step S7, the density Dst of the thinner used for cleaning is set. This is because the mass flow rate of the thinner obtained from the thinner mass flowmeter 4Y is used as a basic value for comparative calculation of the set mass flow rate. Step S8 is a discharge amount Q of the paint based on the paint color parameter i and the vehicle type parameter j.
v (i, j) is set, and subsequently, in steps S9 and S10, conversion values Kx, Ky of the electro-pneumatic conversion devices 10X, 10Y are calculated based on the paint color parameter i and the vehicle type parameter j.
Are set to Ksx (i, j) and Ksy (i, j), respectively. Next, the mass flow rates Qmx and Qmy of the paint and thinner are calculated in steps S11 and S12, and the electro-pneumatic converter 10 is calculated in steps S13 and S14.
Conversion values Kx and Ky are output for X and 10Y, respectively. Then, in step S15, the coating area number parameter k is initialized, and in step S16, it is determined whether or not the coating area number is satisfied. If it is satisfied, the conversion value Kx = 255 is set in the electro-pneumatic conversion device 10X in step S17.
Is output and the air operation 9X is fully opened. Note that step S18 is for waiting for the empty truck to leave the painting line when the empty truck is detected in step S3.

When the number of coating areas is not satisfied, as shown in FIG. 3, first, in step S19, the reciprocal parameter L of the coating machine is initialized, and then in step S20, it is determined whether or not the pushout signal is received from the arithmetic processing unit 1 of the main body. To be determined. If the push-out signal has not been received, the Pu = O flag is set in step S21, and if it has been received, the Pu = 1 flag is set in step S27. Step S2
2. In S28, the paint discharge ON signal is sent to the main processing unit 1
It is determined whether or not the flow rate of the paint is received, and if it is received, τ ₀ seconds later, it is determined in steps S24 to S26 and S33 whether the paint flow rate is excessive or insufficient, and in steps S30 to S32 and S.
At 33, it is determined whether the thinner flow rate is excessive or insufficient.

In the discharge amount control device of the present invention, the paint discharge ON signal is given as an intermittent pulse signal which is synchronized with the reciprocating cycle of the nozzle 3, and steps S24 to S are performed for each pulse.
26 or the sampling process of steps S30 to S32. At this time, steps S23 and S29 are for waiting for the response outputs of the mass flowmeters 4X and 4Y to converge and stabilize.

If there is an excess or deficiency in the flow rate of the paint or thinner, it is first determined in step S34 whether or not pushout is in effect. If no pushout is in effect, then in steps S35 and S36 the electro-pneumatic conversion device 10X is operated. The conversion value is set again and the correction value Δk is set, and when the push-out is applied, the conversion value of the electro-pneumatic conversion device 10y is set again and the correction value Δk is set in steps S37 and S38. . Next, in step 39, it is determined whether the electro-pneumatic conversion device has an increase correction or a decrease correction. In steps S40 and S41, increase / decrease corrections are calculated, and in step S42, the suitability of the new conversion value T is determined, and 0 ≦ T ≦ In the case of 255, K = T is replaced as it is as an appropriate value in step S46, and T <0.
Alternatively, when T> 255, the processing is performed in steps S43 to S45 or steps S47 to S49, respectively.

After completing the correction calculation of the electro-pneumatic conversion device K, step S
At 50, it is determined again whether push-out is applied. If not, the new conversion value K is output to the electro-pneumatic conversion device 10x at step S51, and the value is stored at step S52. . If push-out is being applied, the new conversion value K is output to the electric / pneumatic conversion device 10y in step S53, and step S5 is executed.
The value is stored at 4.

Next, in step S55, it is determined whether or not the paint discharge OFF signal is received from the main body arithmetic processing unit 1 (whether or not one stroke of the nozzle 3 is completed). If received, the nozzle 3 is reciprocated in step S56. It is determined whether or not the stroke is completed. When only the forward stroke is completed, the reciprocal parameter L is incremented in step S57, and then the processing from step S20 is repeated. When the reciprocating stroke is completed, it is determined in step S58 whether or not the coating is continued. If the coating is continued, the processing from step S19 is repeated, and if not continued, the coating area number parameter k is incremented in step S59. The process from step S16 is repeated.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications can be made. For example, the processing flow of the microcomputer 2 is the same as that described above. It may be replaced with another processing flow that fulfills the above. Further, the present invention is applicable not only to a painting machine for an automobile body but also to various painting machines accompanied by a change in coating color.

<< Effects of the Invention >> The present invention, as described above, pushes out the coating material by the cleaning liquid just before the end of coating, and operates the cleaning liquid regulator and the cleaning liquid mass flowmeter after the so-called push-out is applied,
Since the flow rate of the cleaning liquid is accurately controlled by these, it is possible to improve the accuracy of the flow rate control of the push-out paint, and thereby to optimize or equalize the coating thickness of the coating surface at the end of blowing the nozzle. It is possible,
As a result, the effective use of the push-out paint can be achieved, and the cost of painting can be reduced.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a paint discharge amount control device, and FIG.
FIG. 3 and FIG. 3 are flowcharts of the microcomputer. FIG. 4 is a schematic configuration diagram of a conventional paint discharge amount control device. 1 …… Automatic coating machine main processing unit 2 …… Microcomputer 3 …… Nozzle 4x …… Paint mass flowmeter 4y …… Thinner mass flowmeter 9x …… Paint air operation regulator 9y …… Thinner air operation Regulators 10x, 10y ...... Electro / pneumatic converter 14 ...... Color change valve group 16 ...... Paint supply pipe 17 ...... Cleaning thinner supply pipe 18 ...... Air supply pipe 20 ...... Paint ON-OFF valve 21 ...... Paint Supply passage 22: thinner (cleaning liquid) supply passage

Claims (1)

[Claims] 1. A paint regulator and a paint mass flow meter are respectively provided in a paint supply passage connecting a paint nozzle and a color change valve group, and the paint regulator is controlled based on a detection result of the mass flow meter. In a paint discharge amount control device that is operated to control the discharge amount of paint, a cleaning liquid regulator and a mass flow meter for cleaning liquid are provided in the cleaning liquid supply passage connected to the cleaning liquid valve of the color change valve group. When each is arranged, and when the coating material is pushed out and the remaining coating material in the coating material supply passage is extruded with the cleaning liquid to continue coating, from the operation of the coating material regulator based on the detection result of the coating material mass flow meter, Control the flow rate of the cleaning liquid by switching to the operation of the cleaning liquid regulator based on the detection result of the cleaning liquid mass flow meter. Discharge amount control apparatus for paint, characterized in that so as to control the discharge amount of the remaining paint by.