JP4020584B2 - Nozzle cleaning method for spray coating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle cleaning method for a spray coating apparatus.
[0002]
[Prior art]
A coating method using a spray gun is widely known as a coating device for fiber reinforced cement outer wall materials.
[0003]
By the way, in this coating system, a large number of spray guns are arranged in a direction perpendicular to the transfer direction of the outer wall material, and paint is sprayed intermittently or continuously from the spray nozzle as appropriate based on the control signal along with the transfer of the plate material. In some cases, the outer wall material surface is colored and painted.
[0004]
In the above spray coating apparatus, if any one of the spray nozzles is clogged, the target coating cannot be performed, so that sufficient care is required for cleaning.
[0005]
As a nozzle cleaning means for that purpose, conventionally, a liquid that dissolves the paint is included in the brush, and the paint attached by scraping the nozzle tip artificially or mechanically is removed, or the air nozzle at the tip of the nozzle is replaced with air. For example, the liquid is sprayed to dissolve and wash the paint.
[0006]
[Problems to be solved by the invention]
However, since the former cleaning means needs to stop the line, if it is performed too frequently, it will extend the time of the coating process, and therefore it is not suitable.
[0007]
The latter cleaning means has a problem that if the liquid for re-dissolving the paint remains in the air path, the liquid pops out at the time of resuming the coating, resulting in poor coating.
In particular, when spray patterns are sprayed and applied at arbitrary positions and concentrations and applied in a pattern-added manner, many nozzles are used infrequently, or conversely, high nozzles are mixed. In order to ensure that the nozzles are always in perfect condition, cleaning must be complete.
[0008]
In view of the above, the present invention has been made in order to ensure that a large number of spray guns that are arranged in parallel are always uniformly cleaned and in a perfect state even when there is a difference in frequency of use.
[0009]
[Means for Solving the Problems]
That is, the nozzle cleaning method of the spray coating apparatus according to claim 1 is based on the detection information of the approach of the plate material on the conveyor, and the spray coating device is configured to operate continuously or intermittently on the surface of the plate material according to a predetermined control command. In the nozzle cleaning method, as one cleaning step , the paint supply pressure is increased during a period when the spray gun that operates based on the detection information of the plate material is not applied, and the opening and closing needles of the spray gun are moved in a short cycle. in is several times opening movement, to remove the paint droplets staying in the nozzles of the spray gun by continuing to supply air from the atomizing air supply port of the spray gun in that state, as a two washing steps, by spray coating device When the painting process has elapsed for a certain period of time, the conveyor is stopped and the spray gun air path is supplied with a liquid in which the paint can be dissolved again and sprayed. Both perform air injection to blow off these residual droplets, and then scrape and clean with a brush, and the brush is a rotating brush that is driven to rotate by bringing the outer periphery into contact with the nozzle tip. It has a declination with respect to the moving direction with respect to the nozzle .
A nozzle cleaning method for a spray coating apparatus according to claim 2, wherein the nozzle cleaning of the spray coating apparatus is configured to operate continuously or intermittently on the surface of the plate material in accordance with a predetermined control command based on detection information of the plate material approach on the conveyor. In this method, as one cleaning step, the paint supply pressure is increased during a time period when the spray gun that operates based on the detection information of the plate material is not coated, and a plurality of opening and closing needles of the spray gun are provided in a short cycle. In this state, the paint drops staying at the nozzle of the spray gun are removed by continuing to supply air from the atomizing air supply port of the spray gun. In each painting process, the conveyor is stopped, the spray gun air path is supplied with a liquid in which the paint can be re-dissolved, sprayed and Air injection that blows off the droplets is performed, and then the brush is scraped off and cleaned. The brush is a rotating brush that is driven to rotate by bringing the outer periphery into contact with the nozzle tip, and the rotation axis of the rotating brush moves relative to the nozzle. It has a declination with respect to the direction.
According to a third aspect of the present invention, the nozzle cleaning method of the spray coating apparatus is such that the time zone during which the spray gun is not applied is obtained continuously on the surface of the plate material according to a predetermined control command after obtaining the detection information of the plate material on the conveyor. This is a period until the operation is intermittently started.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described.
1 is a plan view of an exterior wall material coating apparatus according to an embodiment, FIG. 2 is a front view of the exterior wall material coating apparatus according to an embodiment, FIG. 3 is a cross-sectional view of a spray gun, and FIG. It is the graph which showed an example of the cleaning schedule of the coating device shown in FIG.
[0019]
In FIG. 1, reference numerals 1... 1 denote spray guns arranged in a large number, which are supported by a base frame 2 on a conveyor 11 on which an outer wall material 10 is transferred, in a direction perpendicular to the transfer direction.
[0020]
Then, painting is performed by continuous or intermittent spraying of each spray gun 1... 1, but when a spray pattern is expressed as a circle to an ellipse, a circular or elliptical spray pattern can be expressed by a single spray. It is a short injection time so that can be drawn.
[0021]
FIG. 3 is a cross-sectional view showing the structure of the spray gun 1.
A spray gun 1 in this coating apparatus includes a base body 1c and a cover plate 1b having a nozzle 1a for spraying paint in a spray form. The base body 1c includes an atomizing air passage 2 and a paint passage. 3 is formed concentrically, and an atomizing air supply port 4 and a paint supply port 5 communicating with the passages 2 and 3 are provided.
[0022]
The nozzle 1a of the cover plate 1b is concentrically positioned and fixed to the openings of the atomizing air passage 2 and the paint passage 3 of the base body 1c, and the open / close needle 6 is concentric with the paint passage 3 Has been placed.
[0023]
In FIG. 3, reference numeral 10 denotes a bracket for the solenoid 7, which is attached to a support member 11 fixed to the base body 1 c of the spray gun 1 via an adjustment screw 12.
[0024]
Such spray guns 1 are arranged as shown in FIGS. 1 and 2, and they are individually injected according to a predetermined command.
Under such injection conditions, which spray gun injects the paint or when it is stopped is commanded from a control device (not shown) and is injected in accordance with the transfer speed of the outer wall material 10.
[0025]
In this case, there is a possibility that the paint 3a stays in the form of droplets 3p as shown in FIG.
Therefore, cleaning is performed according to the time table shown in FIG. 4 so that paint droplets may be generated in any spray gun 1.
[0026]
In the graph of FIG. 4, black portions indicate the operation or actual operation of the apparatus.
The outer wall material 10 is transported on the conveyor 11 to the position where the spray guns 1... 1 are arranged, but is detected by the detection device 14 before a certain distance L (T1 in FIG. 4).
[0027]
Based on this detection signal, a cleaning command is issued to all the spray guns 1... 1 using the time lag (T1 to T3 in FIG. 4) until the outer wall material 10 approaches the spray guns 1. T1-T2).
[0028]
Based on this cleaning command, the supply pressure from the paint supply port 5 is increased by about 1.2 to 2.0 times the normal supply pressure, and at the same time, the opening / closing needle 6 is opened several times in a short cycle.
[0029]
At this time, air continues to be supplied from the atomizing air supply port 4, and as the air is blown out, the paint blows out vigorously from the tip of the spray gun 1, and the accumulated paint drops blow off at this time. Will be.
[0030]
Next, when the outer wall material 10 comes close to the position immediately below the spray gun 1, the cleaning command is finished and a coating command is issued (T3 in FIG. 4).
And based on this coating instruction | command, a coating material is apply | coated to predetermined | prescribed density | concentration and color on the outer wall material 10 surface.
[0031]
At this time, since the cleaning is performed for all the sprays all at once, the nozzles 1a of all the spray guns 1 are in a good state with no paint droplets when entering the painting process.
[0032]
Therefore, uniform coating is possible.
When the coating process is completed (T4 in FIG. 4) and the outer wall material 10 has passed directly under the spray gun 1, the same spray gun 1 may be cleaned again (T5 to T6 in FIG. 4). ).
[0033]
In the above method, there is a possibility that the paint stays in the vicinity of the nozzle 1a within a long period of time only by so-called discharge cleaning by high-pressure jetting of the paint and compressed air.
Therefore, cleaning with a brush is performed.
[0034]
This cleaning is performed based on the total usage time of the spray gun 1.
In FIGS. 1 and 2, reference numeral 13 denotes a cleaning rotary brush, which is pivotally supported so that the outer periphery 13a rotates in contact with the spray port 1a of the spray gun 1, and is driven to rotate by a motor 13b. The rotating brush 13 is supported on the moving base 13c together with the motor 13b, and is movable in parallel along the arrangement direction of a plurality of spray guns 1 ... 1.
[0035]
The rotating shaft 13d of the rotating brush 13 is supported in a state having a declination θ with respect to the arrangement direction of the spray guns 1... It is made to contact uniformly.
[0036]
Next, a cleaning method using the above apparatus will be described.
FIG. 6 is a graph showing an example of the cleaning schedule of the cleaning method.
In the painting process, the total injection time of the spray gun 1... 1 is obtained from the integration of the injection command in the control circuit (not shown), or the actual injection time of the spray gun 1 is obtained from the integration of the operation time of the solenoid 4. If it is time, a cleaning command is issued (T10 in FIG. 6).
[0037]
Based on this command, a timer for managing the cleaning process is started (T10 in FIG. 6), and the outer wall material 10 is detected by this timer start (˜T12 in FIG. 6).
[0038]
When the outer wall material 10 finishes passing (T12 in FIG. 6), the conveyor 11 is stopped (T13 to T17 in FIG. 6), and cleaning is started (T13 in FIG. 6).
At this time, it goes without saying that the outer wall material 10 is controlled so as not to be positioned directly below the spray gun 1 of the coating apparatus.
[0039]
First, a liquid for re-dissolving the paint, for example, water for a water-based paint or a solvent such as thinner for a resin-based paint is ejected from the air discharge port of the spray gun 1 (T13 to T14 in FIG. 6). 3p of paint droplets deposited on is dissolved. Next, air is blown out, and the paint droplet 3p dissolved in the liquid for re-dissolving the paint and attached to the tip of the spray gun 1 is blown off (T14 to T15 in FIG. 6).
[0040]
Next, while rotating the rotating brush 13, it travels in the arrangement direction of the nozzles 1a to scrape off the attached paint (T15 to T16 in FIG. 6).
Since the rotary shaft 13d has a declination angle θ, the rotary brush 13 rotates because the jet nozzle 1d comes into spiral contact with the outer surface of the rotary brush when the rotary shaft 13d is translated in a rotated state. Only a part of the brush is not worn, and the brush 13a can have a long life.
[0041]
Then, after the reciprocating cleaning with the rotating brush 13a is repeated as many times as necessary (twice in FIG. 6), so-called spouting is performed in which the coating material is pressurizedly supplied from the coating material supply port 5 and ejected in a short time, and remains in the air path. Completely remove the liquid that dissolves the paint.
[0042]
Thereafter, the painting process is resumed.
Therefore, if this cleaning process is performed every predetermined time, the vicinity of the spray gun nozzle 1a is always kept clean, and adverse effects due to the stagnation of the paint are prevented.
[0043]
In the above description, the case where the start of cleaning is based on the spray gun integration time has been described. However, periodic cleaning by a timer may be used.
Furthermore, it may be combined with the cleaning for each painting process described in the previous cleaning.In this case, the cleaning interval is counted and the number of cleanings is counted each time in addition to the integration and timer. May be.
[0044]
【The invention's effect】
Since the present invention is configured as described above, according to the first aspect of the present invention, when the outer wall material surface is automatically coated with a spray gun, cleaning is performed by spraying the nozzle together with the coating of the outer wall material. Therefore, painting can always be performed under uniform conditions, and a beautiful painted surface as controlled is obtained. According to the second aspect of the present invention, cleaning and painting can be performed with a single detection, and the detection process can be simplified.
[0045]
According to the invention of claim 3, since cleaning with a spray and cleaning with a brush are periodically performed every time a certain painting process progresses, it is possible to reliably prevent the paint from staying at the spray gun outlet and to be stable over a long period of time. You can continue painting.
[0046]
According to the invention of claim 4, since the cleaning for each coating is performed in combination with the cleaning for every fixed period, the state of the spray gun outlet can be kept better.
According to the fifth aspect of the present invention, the contact surface of the rotating brush with respect to the ejection port is uniform over the entire surface, so that the brush outer surface is prevented from being reduced and the life of the rotating brush can be extended.
[Brief description of the drawings]
FIG. 1 is a plan view of an essential part of a coating apparatus for an outer wall material.
FIG. 2 is a front view of a main part of a coating apparatus for an outer wall material.
FIG. 3 is an explanatory sectional view of one spray gun of a coating apparatus for an outer wall material.
FIG. 4 is a time table showing cleaning times.
FIG. 5 is an explanatory diagram showing a state of nozzle cleaning.
FIG. 6 is a time table showing a cleaning method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spray gun 1a Spout 2 Base frame 10 Outer wall material 11 Conveyor 13 Rotating brush

Claims (3)

A nozzle cleaning method for a spray coating apparatus that is operated continuously or intermittently according to a predetermined control command on the surface of the plate material based on detection information of the plate material approach on the conveyor,
As one cleaning step, in the time zone when the spray gun that operates based on the detection information of the plate material is not coated, the paint supply pressure is increased, and the opening and closing needle of the spray gun is opened and released several times in a short cycle, In that state, by continuously supplying air from the atomizing air supply port of the spray gun, the paint drops staying at the nozzle of the spray gun are removed ,
As the second cleaning process, when the coating process by the spray coating device has passed for a certain period of time, the conveyor is stopped, the liquid in which the paint can be re-dissolved is supplied to the air path of the spray gun, and the residual drops are sprayed. Air blow to blow away,
The brush is then scraped off and cleaned, and the brush is driven to rotate by bringing the outer periphery into contact with the tip of the nozzle, and the rotating shaft of the rotating brush has a declination with respect to the moving direction relative to the nozzle. nozzle cleaning method of the spray coating device, characterized in that is. A nozzle cleaning method for a spray coating apparatus that is operated continuously or intermittently according to a predetermined control command on the surface of the plate material based on detection information of the plate material approach on the conveyor,
As one cleaning step, in the time zone when the spray gun that operates based on the detection information of the plate material is not coated, the paint supply pressure is increased, and the opening and closing needle of the spray gun is opened and released several times in a short cycle, In that state, by continuously supplying air from the atomizing air supply port of the spray gun, the paint drops staying at the nozzle of the spray gun are removed,
As a second cleaning process, the conveyor is stopped for each coating process performed by the spray coating device, a liquid in which the paint can be re-dissolved is supplied to the air path of the spray gun, sprayed, and these residual drops are removed. Air blow to blow away,
The brush is then scraped off and cleaned, and the brush is driven to rotate by bringing the outer periphery into contact with the tip of the nozzle, and the rotating shaft of the rotating brush has a declination with respect to the moving direction relative to the nozzle. nozzle cleaning method of the spray coating device, characterized in that is. The time period during which painting by the spray gun is not performed is the period from when the detection information on the approach of the plate material on the conveyor is obtained until the operation is started continuously or intermittently on the surface of the plate material according to a predetermined control command. The nozzle cleaning method of a spray coating apparatus according to claim 1 or 2, wherein

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