JP2506202B2 - Coating equipment - Google Patents

Description

Description: [Industrial field of use] The present invention relates to a coating apparatus configured to heat or warm high-pressure air or a coating material supplied to a coating machine.

[Conventional technology]

In recent years, in response to the rise of global environmental conservation movements, the coating industry is reconsidering coating with water-based paints that do not use harmful organic solvents such as thinner from the viewpoint of pollution prevention.

However, water-based paint evaporates slowly, so
It is said that it is very difficult to obtain a high quality and thick coating film because it has a drawback that the coating film tends to flow and sagging.

For this reason, the conventional coating device heats the high pressure air supplied to the air spray type coating machine, and uses the heated high pressure air as atomizing air or pattern air for atomizing and spraying the paint, By being used as atmospheric air that regulates the temperature and humidity of the surrounding atmosphere where the paint is sprayed, it promotes evaporation of the water contained in the paint particles and reduces the water content when applied to the surface of the coated object. To prevent the flow and sagging of the coating film (Japanese Patent Laid-Open No. 51-45141;
51-115548 and 52-129747).

In addition, high viscosity aqueous paints have poor spraying workability,
This is heated so as to have a low viscosity and sprayed (see JP-A-49-133435 and JP-A-54-69148).

[Problems to be Solved by the Invention]

However, conventionally, in order to heat the high-pressure air supplied to the coating machine, a part of the air supply pipe connected between the coating machine and the compressor is formed into a coil shape, and the coiled portion is formed. Since the coil-type heat exchanger provided with the electric heater is used, there is a problem that the equipment cost of the equipment increases and the installation space also increases.

In particular, the coil type heat exchanger has a high power cost, and a long heat-insulating hose must be used for the air supply pipe interposed between the heat exchanger and the coating machine. High cost.

Further, when heating a high-viscosity water-based paint, a heat source such as an electric heater is required, which causes a problem of increased equipment cost and running cost.

Therefore, the present invention has a technical object to significantly reduce equipment costs, running costs, and installation space of equipment necessary for heating or heating paint or high-pressure air supplied to a coating machine.

[Means for solving the problem]

In order to solve this problem, the coating apparatus according to the present invention has a high pressure in an air passage formed along a paint pipe for supplying the paint to the coating machine, or in an air supply pipe for supplying high pressure air to the coating machine. A hot air outlet of a swirl cooler for generating hot air and cold air by converting high-pressure air supplied from an air supply source into a swirling flow swirling at high speed is connected.

[Action]

According to the present invention, the hot air discharged from the hot air outlet of the swirl cooler is sent to the air passage formed along the paint pipe for supplying the paint to the coating machine and supplied to the coating machine through the paint pipe. The paint is heated and the viscosity of the paint decreases.

This improves the spraying workability of the highly viscous water-based paint.

In addition, the hot air is supplied to the coating machine through an air supply pipe for supplying high-pressure air, and is ejected as atomized air, pattern air, or atmospheric air heated from the coating machine, and in the paint particles sprayed from the coating machine. The evaporation of the water contained in is promoted.

As a result, the water content of the water-based paint applied to the surface of the article to be coated decreases, and the flow and sagging of the coating film are prevented.

[Example I]

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a sectional view showing an example of a coating apparatus according to the present invention.

In this example, hot air is supplied from the high-pressure air supply source 2 to the air supply pipes 1a and 1b for supplying two high-pressure air systems, which are atomized air and pattern air, to the air spray type electrostatic coating machine G. And a hot air outlet 4 of a swirl cooler 3 for generating cold air are connected.

Here, the vortex cooler 3 directs the high-pressure air supplied from the high-pressure air supply source 2 such as a compressor to the high-pressure air supply port 5 to the circumferential surface in the vortex flow generating chamber 6 in the tangential direction thereof at the sonic velocity. At the same time as it is discharged and expanded, it is turned into a swirling flow that swirls at high speed and is sent into the tube 7.

Then, the vortex flow fed into the tube 7 moves to the control valve 8 provided at the end of the tube 7, and a large centrifugal force acts on the vortex flow to rapidly increase the pressure and the density. It rises and becomes hot air and is discharged from the hot air outlet 4.

At the same time, the inner vortex generated in the inner cavity by the centrifugal force of the vortex flows in the same direction as the outer vortex that becomes hot air, and at the cold air outlet 9 opening on the opposite side to the hot air outlet 4. It moves toward the opposite direction, and in the process of moving, it works against the outer vortex due to the braking action by deceleration, the temperature drops, and it becomes cold air and is discharged from the cold air outlet 9.

That is, the swirl cooler 3 has an extremely simple structure without a driving part, and does not require a heat source such as an electric heater at all, and can generate hot air and cold air at the same time only by supplying high pressure air.

Then, the high-pressure hot air produced by the vortex cooler 3 is supplied from the hot air outlet 4 to the atomizing air nozzle 10 and the pattern air nozzle 11 through the respective air supply pipes 1a and 1b, and the hot air from the nozzles 10 and 11 is supplied. Sprayed as atomized air and pattern air from the tip.

As a result, the paint discharged from the paint nozzle 13 opened and closed by the needle 12 is atomized by the hot air ejected from the atomizing air nozzle 10 and sprayed, and at the same time heated by the hot air.

Therefore, the viscosity of the high-viscosity water-based paint is lowered, and the spraying workability is improved.

Further, the paint particles sprayed from the paint nozzle 13 are heated or heated by the hot air ejected from the pattern air nozzle 11 to accelerate the evaporation of the water contained in the particles.

Therefore, when it is applied to the surface of the article to be coated, the water content is reduced, so that the flow and sagging of the coating film are prevented.

The amount of hot air discharged from the hot air outlet 4 of the vortex cooler 3 is determined by adjusting the control valve 8,
The temperature of the hot air is, as shown in FIG. 2, the temperature (° C.) and the pressure (kg / cm ² G) of the high pressure air supplied to the high pressure air supply port 5 of the vortex cooler 3, the hot air and the cold air. It is determined by the ratio (% of cold air).

That is, the performance of the swirl cooler 3 will be described with reference to FIG. 2. The high-pressure air supply source 2 to the supply port 5 of the swirl cooler 3 will be described.
The high pressure air supplied to the unit has a temperature of 21 ° C and a pressure of 1.4 kg / cm ² G
At this time, if the cold air ratio is adjusted to 50%, 60% by operating the control valve 8, the temperatures of the hot air discharged from the hot air outlet 4 to the air supply pipes 1a, 1b are 48.5 ° C and 56.6 ° C, respectively.
℃.

Therefore, even if the pressure or temperature of the high-pressure air supplied from the high-pressure air supply source 2 changes, atomized air or pattern air close to a desired temperature can be obtained by a simple operation of adjusting the control valve 8. it can.

Further, the amounts of atomizing air and pattern air are determined by the vortex cooler 3
Are individually adjusted by the needles 14 and 15 interposed at the connection between the hot air outlet 4 and the air supply pipes 1a and 1b.

The hot air outlet 4 of the swirl cooler 3 is provided with air supply pipes 1a and 1b for supplying atomized air or pattern air as in the above embodiment.
However, the air may be connected to the air supply pipe for the atmospheric air that is jetted from the periphery of the coating machine G to adjust the surrounding atmosphere.

Also, connect these air supply pipes directly to the compressor,
The hot air outlet 4 of the vortex cooler 3 is branched and connected in the middle of the air supply pipe, and hot air discharged from the hot air outlet 4 and high pressure air supplied from the compressor are mixed to produce hot air. May be.

Example II

Next, FIG. 3 is a sectional view showing another embodiment of the present invention.

In this example, an air passage 18 having a predetermined length is formed along a paint pipe 16 for supplying paint to the airless spray type electrostatic coater G, and a resin pipe 17 covering the circumference of the paint pipe 16. The hot air outlet 4 of the vortex cooler 3 is connected to one end of the air passage 18, and the hot air exhaust port 19 is opened to the other end.

The eddy current cooler 3 is fixed along the outside of the pipe 17.

As a result, the high-viscosity water-based paint supplied to the coating machine G through the paint pipe 16 is heated in the pipe and becomes in a state where the viscosity is lowered, so that the spraying workability is improved.

Further, a paint valve 20 for turning on and off the paint supplied through the paint pipe 16 is provided in the painting machine G, and the valve 20 has a valve body 24 for opening and closing a paint passage 22 leading to a paint nozzle 21. The needle valve 23, a movable core 27 that is fixed to the other end of the needle valve 23 and presses the valve body 24 against the valve seat 26 by the elasticity of the spring 25, and the energization controller 28 oscillates at a predetermined pulse cycle. A solenoid coil 29 that lifts up the movable core 27 in the valve opening direction of the needle valve 23 against the elasticity of the spring 25 each time an energizing pulse is input.

In the body 30 that guides the movable core 27, the movable core 27 is lifted up to fully open the needle valve 23.
A stopper 32 that causes the flange portion 31 to collide is provided, and the needle valve 23 is opened and closed by vibrating at a stroke corresponding to a gap provided between the flange portion 31 and the stopper 32.

In addition, the body 30 is provided with a connector portion 34 for connecting the paint pipe 16 to the paint passage 22 and fixing one end of the pipe 17 covering the paint pipe 16 by screwing.

Further, the wiring passage of the lead wire 35 for inputting the energizing pulse oscillated from the energizing controller 28 to the solenoid coil 29.
36 is provided, and an explosion-proof switch 38, which is interposed in the lead wire 35 and turns on / off the power supply to the solenoid coil 29 by operating the trigger 37, is provided in the wiring passage.

Then, when painting, pull the trigger 37 to turn on the explosion-proof switch 38, and paint coil 20 solenoid coil.
At 29, an energizing pulse is input at a preset pulse cycle according to the paint discharge amount of the coating machine G, the needle valve 23 is opened and closed at high speed to turn on the paint, and at the same time, the paint is sprayed from the paint nozzle 21 in a predetermined manner. It is possible to discharge at a discharge amount.

Further, the amount of paint to be discharged from the coating machine G can be freely adjusted only by changing the energizing time or the pulse cycle of the energizing pulse input to the solenoid coil 29.

At this time, due to heat generation of the solenoid coil 29,
Although it may damage the coil 29, the switch 38, etc.,
As shown in the figure, if the cold air outlet 9 of the eddy current cooler 3 is connected to the wiring passage 36 of the lead wire 35 leading to the inside of the body 30 in which the solenoid coil 29 is provided, the cold air discharged from the eddy current cooler 3 is effectively used. As a result, heat generation of the solenoid coil 29 can be prevented.

Also, a lead wire that serves as a power supply line to the solenoid coil 29.
The switch 38 mounted on the 35 is enlarged in order to prevent explosion, but it can be replaced with a switch such as a barrier relay that is installed on a dedicated signal line provided separately from the power supply line to the solenoid coil 29. In this case, explosion-proof measures are unnecessary and the size can be reduced.

Further, the coating machine according to the present invention is not limited to the air spray type or the airless spray type, and may be a rotary atomizing type.

〔The invention's effect〕

As described above, according to the present invention, the paint or high-pressure air supplied to the coating machine is heated or heated by the high-pressure hot air discharged from the hot air outlet of the vortex cooler, and the vortex cooler is No heat source such as an electric heater is required, hot air can be generated only from high pressure air, and it is very small and lightweight and can be installed in a coating machine. Nor.

Further, since the swirl cooler does not have an electric system, it is not necessary to take explosion-proof measures or insulation measures.

Therefore, there is a very excellent effect that equipment cost, running cost, and installation space required for heating or heating the paint or high-pressure air supplied to the coating machine are significantly reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a coating apparatus according to the present invention, FIG. 2 is a table showing the performance of a vortex flow cooler used therein, and FIG. 3 is a sectional view showing another embodiment of the present invention. Explanation of symbols G …… Coating machine, 1a, 1b …… Air supply piping, 2 …… High pressure air supply source, 3 …… Vortex flow cooler, 4 …… Hot air outlet, 16 …… Paint piping, 18 …… Air passage .

Claims (2)

(57) [Claims] 1. Hot air by changing the high-pressure air supplied from a high-pressure air supply source (2) into a swirl swirling at high speed in air supply pipes (1a), (1b) for supplying high-pressure air to a coating machine (G). And a hot air outlet (4) of a swirl cooler (3) for generating cold air are connected. 2. High-pressure air supplied from a high-pressure air supply source (2) is swirled at high speed in an air passage (18) formed along a paint pipe (16) for supplying paint to a coating machine (G). A coating device characterized in that a hot air outlet (4) of a swirl cooler (3) for generating hot air and cold air in place of a swirl is connected.