JPS591106B2 - Discharge rate control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge amount control device that selects a unique and optimal paint discharge amount under various coating conditions and supplies the selected paint discharge amount.

It is well known that paints are significantly affected by temperature and humidity, resulting in significant changes in viscosity and various changes in physical properties of paints, such as atomization, coating strength, etc.

In addition, the current demand for automatic painting, which has led to cost reductions, is also requiring higher conveyor speeds, multiple color changes, and more precise paint discharge control, with the aim of achieving even greater resource-saving effects. ing. However, it is somewhat contradictory to grasp the characteristics of paints that change their physical properties in response to external temperature, etc., and quickly apply paints that match the paint conditions at that time. The cost of equipment had to be enormous.

Therefore, in the past, a manually set spring-type paint regulator was often used on the primary side of the paint color changing device to control the discharge amount, and it was often necessary to set the discharge amount as the paint conditions changed. It takes a lot of time.

The reason for this is that the painting conditions mentioned here include all factors surrounding the paint, so when controlling the discharge amount by manual setting, it is necessary to add the temporal temperature change value to the operator's experience and intuition. Because he had no choice but to do so. In such manual setting, the ejection amount control must be gradual and coarse control, and fine control by analog control cannot be desired. Also, instead of the spring-type paint regulator mentioned above, an air-operated paint regulator may be used, but in this case, several air regulators are required for each paint color, so As the number of air regulators increases, a huge number of air regulators are required.

Here, examples of the drawbacks of the above-mentioned two conventional devices are as follows.

For example, when the line starts working in the morning in winter, the viscosity of the paint is high, so the necessary discharge amount cannot be obtained, resulting in paint defects. For this reason, if you set the optimal discharge rate when the line starts in the morning, the room temperature will rise over time.
Since the paint viscosity decreases and the discharge amount increases, the film thickness becomes too large or sag 7 occurs, resulting in poor coating. Such a phenomenon does not only apply to the seasons, but can also occur throughout the day, and it is natural to think of increasing or decreasing the line speed to eliminate this problem, but this operation requires considerable effort. Due to the difficulties involved, it has not been implemented at present. Also, especially when the line speed is high,
Painters with a small discharge amount take time to fill the color changing device and the paint path to the paint machine with paint, making it impossible to quickly change colors, making them unusable. SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge rate control device that eliminates the various drawbacks of the prior art described above and can always maintain an optimum paint discharge rate that matches the coating conditions.

The present invention includes a paint color changing device interposed between a paint circulation and a coating machine and controlled to open and close by an air pilot signal; an air-operated paint regulator installed in a paint passage connecting the paint passages; a central processing unit that calculates painting conditions such as paint viscosity and generates an analog electrical signal for controlling the discharge amount; an electro-pneumatic conversion device that converts an analog electrical signal into an air pressure signal;
The discharge amount control device is characterized by comprising a transmission path for transmitting an air pressure signal generated by the electro-air converter to the air-operated paint regulator.

Embodiments of the present invention will be described below with reference to the drawings.

The central processing unit 1 includes various factors 2a, 2b, and
2c, 2d, and 2e are input. Here, the factor 2a indicates the paint viscosity, the factor 2b indicates the color change signal, the factor 2c indicates the conveyor speed, the factor 2d indicates the area of the object to be coated, and the factor 2e indicates the paint characteristics. The factor 1 input to the central processing unit 1 is not limited to those listed here, and various factors can be considered as the factor 1 based on the calculation function of the central processing unit 1.
Taking the viscosity of paint as an example, the central processing unit 1 is preprogrammed with data as shown in FIG. 2A and 2B.

These diagrams show how the paint viscosity changes depending on the environmental temperature and how the paint discharge rate changes as a result.It is important to collect as many plot points as possible to form a viscosity curve. It is constructed by forming a viscosity table close to the plot point. Of course, similar data can be collected for other factors and programmed into the central processing unit 1 in advance. On the other hand, since the paint color changing device 3 selectively switches the paints of colors A to N, the paint circulations 4a and 4 of each color are
b, . . 4n and the coating machine 5, and each opens and closes separately in response to an air pilot signal flowing in from the X direction.

Then, paint circulations 4a, 4b, .
...4n and each color change bulb 3a, 3b, ...3n
Air-operated paint regulators 7A, 7 are connected to the paint passages 6a, 6b, . . . , 6n, respectively.
b,...7n are interposed. The control air passages 8a, 8b, . . . 8n of these air-operated paint regulators 7A, 7b, . It is connected to an electric to air converter 9. The electric-to-air converter 9 is a device for converting the analog electric signal for controlling the discharge amount issued by the central processing unit 1 into air pressure fluctuation. The opening degrees of the regulators 7A, 7b, . . . , 7n are adjusted in response to analog electrical signals for controlling the discharge amount issued by the central processing unit 1, respectively. In addition,
The paint color changing device 3 has a thinner valve 30 and an air valve 3p for cleaning the paint system path from the paint color changing device 3 to the coating machine 5.

These valves 30 and 3p each have a thinner passage 4.
Thinner or air is supplied from 0 and air passage 4p,
The opening and closing operations of these valves 30 and 3p are performed by air pilot signals X' and X'. 70, 7p indicates a manually set regulator.

A paint supply passage 1 connecting the paint color changing device 3 and the coating machine 5
A paint on-off valve 11 is interposed in the paint on-off valve 11, and one discharge port of the paint on-off valve 11 is connected to a drain tank 13 via a dump valve 12. Of course, the other outlet of the paint on-off valve 11 is connected to the paint sprayer 5. The action will be explained below.

As an example, to explain the case of painting A color,
The central processing unit 1 calculates the coating conditions at this time from the various factors 2a to 2e described above, and issues an analog electric signal for controlling the discharge amount to the electric to air converter 9.

Then, this analog electric signal for controlling the discharge amount is converted into a change in air pressure by the electric-to-air converter 9, and this air pressure causes the air-operated paint regulators 7A, 7 to
b, . . . 7n are all set to opening degrees suitable for the A color painting at this time. Here, if only the color change valve 3a is opened by the air pilot signal Supplied. Thereafter, similar control is sequentially performed for other colors. What is important here is that even while a certain color of paint is being applied, the central processing unit 1 continues to emit an analog electrical signal, so the electric-to-air converter 9 responds to this by emitting an analog air signal. , air-operated paint regulators 7A, 7b, . . . , 7n are each adjusted in opening degree in an analog manner.

Then, when switching to another color, the thinner valve 30 and the air valve 3p act to clean the paint system path in accordance with conventionally known means.

The washed paint is also disposed of into the drainage tank 13 as in the conventional case. As explained above, according to the present invention, the analog air signal of the electro-pneumatic converter is transmitted through a single transmission path, so the control system is extremely simple, and Since it is sufficient to install a single air-operated paint regulator in each case, an extremely compact configuration can be achieved.

Furthermore, since the opening degree of the air-operated paint regulator can be adjusted in an analog manner, fine-grained adjustment of the discharge amount can be performed dynamically in response to momentary changes in the environment, and the central processing unit can Appropriate selection of the factors input into the image forming apparatus also produces the effect that extremely efficient painting can be performed.

Furthermore, since the discharge amount can be appropriately set when changing colors, the amount of paint to be discarded is reduced, resulting in resource conservation.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a schematic configuration of the present invention, FIG. 2A is a relationship between paint viscosity and temperature, and FIG. 2B is a relationship between paint viscosity and discharge amount. 1...Central processing unit, 2a, 2b,...
, 2e...Input factor 3...
...Paint color changing device, 4a,...4n...Paint circulation, 5...Painting machine, 7a,...
..., 7n... Air-operated paint regulator, 8... Transmission path.

Claims (1)

[Claims] 1. A paint color changing device that is interposed between a paint circulation and a coating machine and whose opening and closing are controlled by an air pilot signal, and a paint that connects the paint circulation and the paint color changing device. An air-operated paint regulator installed in the passageway, a central processing unit that calculates painting conditions such as paint viscosity and generates an analog electric signal for controlling the discharge amount, and an air-operated paint regulator that calculates the painting conditions such as paint viscosity and generates an analog electric signal for controlling the discharge amount. A discharge amount control device comprising: an electro-pneumatic converter for converting into a signal; and a transmission path for transmitting an air pressure signal generated by the electro-pneumatic converter to the air-operated paint regulator.