JPS6157068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an automobile paint booth that is equipped with an air curtain.

When painting automobile bodies, etc. with a paint gun, etc., in order to improve the quality of the painting, the working environment, and pollution control, the work space must be well-ventilated and the air containing floating paint particles must be removed from the floor area, especially near the floor. A paint booth is used that removes paint particles and solvent vapor from under the floor to the outside.
In this type of painting booth, air is supplied from a blower to a static pressure chamber formed between the upper wall and ceiling of an almost tunnel-shaped working space, and after the air is passed through a filter to remove dust, a hole is formed in the ceiling. Alternatively, by dropping the paint into the work space at a nearly uniform speed through the grid, in addition to quickly dropping excess paint particles and solvent vapor ejected from the painting gun to the floor, it can also be used for painting objects such as automobile bodies and painting work. An air curtain that blows down from the ceiling is formed between the worker and the worker to prevent floating paint particles and solvent vapor from reaching the worker.

The present inventors focused on the formation of the air curtain-like air flow and improved the air flow in the paint booth with the aim of setting optimal conditions for painting in the paint booth and improving painting quality and work environment. A number of experiments were carried out, including measuring wind speed using a hot-wire anemometer, visual inspection using smoke flow, and measuring the concentration distribution of scattered hydrocarbons by spraying a hydrocarbon solvent with a paint gun. As a result, it was found that it is better to form two parallel air curtains on the surface of the object to be coated to prevent paint particles and solvent vapor from scattering than one, and that it is better to form two parallel air curtains than one to prevent paint particles and solvent vapor from scattering. Of the air curtain-like airflow, the airflow that is formed near the painting worker is directed vertically downward,
If the air flow formed near the object to be painted is tilted from the vertical direction so that the downstream side is directed close to the air flow oriented in the vertical direction, scattering of the paint particles and solvent vapor can be improved. It has been found that the hydrocarbon concentration in the vicinity of the painter's face is significantly reduced.

Furthermore, the air curtain-like airflow is supplied by a duct that is independent of the static pressure chamber formed near the ceiling, and is made independent of the airflow that is supplied from the static pressure chamber into the work space at a uniform speed. It was also found that if the flow rate could be controlled, it would be possible to reduce the hydrocarbon concentration near the painter's face to almost 0 ppm.

The present invention is based on the knowledge obtained from these experiments, and aims to provide a coating booth with extremely good coating quality and working efficiency, and an improved working environment.

Further, the present invention provides two air curtain-like air flows, the air curtain-like air flow directed downward in the vertical direction and the air curtain-like air flow directed obliquely with respect to the vertical direction.
It is an object of the present invention to provide a configuration in which a single air flow is formed to prevent paint particles and solvent vapor from scattering, quickly descend, and improve coating quality.

According to the present invention, an air flow is supplied to the work space evenly downward through the ceiling board from a chamber formed at the upper part of the ceiling board of the work space, and from a duct independent of the chamber, in parallel to the duct. Two air curtain-like air flows are supplied downward into the work space through the formed first and second openings, and the air curtain-like air flows supplied from the first opening are directed downward in the vertical direction. The air curtain-like air flow is directed to and supplied from the second opening at a distance of 150 mm or more from the center point in the width direction of the first opening.
The second opening is oriented in a direction proximate to the air curtain-like air flow supplied from the first opening at an angle of 0 to 50 degrees with respect to the vertical direction, centered on a point separated by 350 mm. A painting booth is provided whose width is 0.5 to 3 times the width of the first opening.

FIG. 1 is a schematic cross-sectional view of an embodiment of the painting booth of the present invention. A ceiling plate 3 in which rod-shaped materials or plate-shaped materials are combined in a lattice pattern and a large number of through holes is stretched over the ceiling plate 3 to form a static pressure chamber 4 between the top of the building 2 and the ceiling plate 3. An air passage 6 that communicates with the discharge side of a blower 5 installed outside the building 2 is made to communicate with the static pressure chamber 4, and a filter 7 is laid entirely on the upper surface of the ceiling plate 3, so that the blower 5 is Dust is removed from the air supplied to the static pressure chamber 4 by a filter 7, and the purified air is blown down into the work space 1 through the through holes in the ceiling plate 3 at a substantially uniform speed. A flow rate control valve 8 is provided in the air passage 6, and the air volume is controlled by rotating around its axis.

The building 2 is provided with a floor plate 9 made of iron plate or lattice-shaped iron material with a large number of through holes, and a discharge space 10 is formed between the floor plate 9 and the bottom of the building 2. 11, and the air on the upper surface of the water 11 is discharged to the outside by an exhaust fan 13 via an exhaust pipe 12. A flow rate control valve 14 is provided in the exhaust pipe 12 to control the amount of exhaust air.

At the upper part of the work space 1, there are side walls 15, 15 extending in the length direction of the tunnel-like work space 1 of the building 2.
Ducts 16 and 17 are located at a predetermined distance from the
are arranged in the static pressure chamber 4 so that their lengths are substantially parallel to the side walls 15, 15, and the openings 18, 19 at their lower ends are hermetically connected to the openings 20 of the ceiling plate 3. The ducts 16 and 17 each have an air passage 22 communicating with the discharge side of the blower 21.
The air from the blower 21 is supplied into the work space 1 from the respective openings 18 and 19 via the air passage 22. A flow rate control valve 23 is provided within the air passage 22, and the amount of air blown is controlled by rotating around its axis.

FIG. 2 is an enlarged view of the lower end of one of the ducts 16 and 17, and the other duct 17 is also constructed symmetrically thereto. In the opening 20 of the ceiling plate 3, a filter 24 is laid entirely on the upper surface of a part 25 such as a wire mesh stretched over the opening 20, and a distribution for forming an air curtain is installed on the lower surface of the opening 20. A device 26 is hermetically secured on both sides thereof.

The distribution device 26 shown in FIG. 1 and FIG. It has a width (width in the left-right direction of the paper in Figure 1),
Two narrow openings 27 and 28 are formed at a predetermined interval in the width direction, and the length directions are parallel to each other, and the air is supplied from the blower 21 to the duct 16 via the air passage 22. is the distribution device 2
It is configured to blow down into the work space 1 from the openings 27 and 28 of 6 in the form of a thin film-like air flow, that is, an air curtain-like air flow.

To explain the details with reference to FIG. 2, the distribution device 26 includes three molded plate members 29, 30, 31 having a length corresponding to the length of the object 104 to be coated.
a plate-like member 2 forming both side edges thereof;
9 and 31 are respectively one side edge of the opening 2 of the ceiling plate 3.
The central plate-shaped member 33 is fixed to the flange 32 forming the edge of 0, and connected to both plate-shaped members 29 and 31 at an appropriate interval in the length direction. arranging the members 30 in a supporting arrangement;
Adjacent edges 29', 30', 31' of each of the plate-like members 29, 30, 31 are made parallel to each other by a certain distance to form openings 27, 28, and the blowdown is caused to flow through the openings 27, 28. An air curtain is formed to direct the direction of air flow. And the building 2 of the distribution device 26 configured as described above.
The direction of air flow from the opening 27 located near the side wall 15 is approximately vertical as shown by arrow A.
The direction of the airflow blown down from the opening 28 located far from the side wall 15 is within an angle range of 20 degrees from the vertical direction, as shown by arrow B, toward the side wall 15, that is, from the opening 27 in the vertical direction. oriented in close proximity to the descending air curtain-like airflow.

In this embodiment, in the distribution device 26 provided at the lower end of the ducts 16 and 17, one opening 27 located near the side wall 15 of the building 2 forming one side wall of the work space 1 is opened as shown by arrow A. By supplying an air curtain-like air flow in the vertical direction to the side wall 15, an air curtain-like air flow is created that blocks floating paint particles between the worker 105 who performs painting work near the side wall 15 and the object to be painted 104. At the same time, by supplying an air curtain-like air flow shown by arrow B from the other opening 28 located further away from the side wall 15, a downward air flow toward the object to be coated is formed. Floating paint particles that are ejected from the surface, collide with the object 104 to be coated, and fly up are quickly guided downward to prevent the floating paint particles from reaching the operator.

Building 2 in this example has a frontage of 5000 mm, a depth of 7000 mm,
The height of the ceiling 3 is 3800 mm, and the height of the ceiling 3 is 2700 mm from the upper surface of the floor board 9. Distribution device 26
The horizontal widths d ₁ and d ₂ of the openings 27 and 28 are 50 mm, respectively, and the lengths are 7000 mm, and the openings 27 and 28 are
The distance between the center points in the width direction of the openings 27 of the distribution devices 26 and 26 attached to the ducts 16 and 17 is set to 1800 mm. There is. As described above, the angle θ between the direction of the air flow blown down from the opening 28 and the vertical line is 20 degrees.

According to this embodiment, a passenger car is used as the object to be painted 104.
In the case of painting, the air curtain-like airflow blown down from the opening 28 in the direction of arrow B does not collide with the object to be painted 104 but flows along the object to be painted 104. The wind speed near the painting surface 104 is not so fast, but is at an extremely appropriate speed in terms of painting quality, and the paint particles that have been ejected from the painting gun and have not adhered to the object 104 to be painted are quickly swept away by the air curtain-like air flow. The painting worker 1
None reached 05.

When this effect is compared with a comparative example device in which an air curtain-like air flow is blown down diagonally downward toward the center of the work space 1 instead of the opening 28 of the distribution device 26, it is found that in the comparative example device, the vertical An air curtain-like air flow blowing down in the direction of the object to be coated 10
4, disrupting the flow and scattering paint particles upward, some of which reach the painter's face, and furthermore, the scattered paint particles hit the object to be painted 10.
A remarkable effect was observed compared to No. 4, which was applied irregularly.

That is, as a result of experiments, it was confirmed that the distance between the openings 27 and 28, the opening area, and the direction of the air curtain-like air flow from the opening 28 significantly affect the rapid descent of floating paint particles. In painting work by
The directional direction of the air curtain-like airflow blown down from the opening 28 is oriented vertically downward from the opening 27 at an angle of 0 to 50 degrees with respect to the vertical direction, and is close to the air curtain-like airflow blown down from the opening 27. It was confirmed that this method eliminates upward scattering of floating paint particles and maintains good coating quality and coating efficiency. In addition, since the air curtain-like air flow requires a flow rate as well as a flow velocity, the openings 27 and 28
The horizontal width dimension of cannot be made too small. As shown in the example, the width of the openings 27 and 28 is
If it is set to 50mm, the distance between openings 27 and 28 will be 150mm.
With the following setting, even if the air curtain-like air flows blown down from both openings 27 and 28 are both directed in the vertical direction, both air flows diffuse near the object to be coated and interfere with each other, causing turbulence. If the direction of direction of the air blowers 28 is tilted, they will interfere with each other at a further upper position, and floating paint particles will be scattered due to the turbulence of both air flows, reducing the effect of improving the working environment. 350
If the distance is more than mm, the distance between the two airflows will be too large and the synergistic effect of the two airflows will be weakened. Openings 27, 28
When the distance between the two openings is set to 250 mm, the air curtain formed from both openings exhibits a synergistic effect, resulting in the best painting efficiency and working environment. Openings 27, 28
It is preferable that the width dimensions d ₁ and d ₂ are the same, but what causes the floating paint particles to descend is mainly the effect of the air curtain-like airflow blown down in the direction of arrow B by the opening 28. Based on this, the width d ₂ of the opening 28 can be 1/2 to 3 times the width d ₁ of the opening 27. When the ratio of d ₂ and d ₁ exceeds 3,
Paint particles riding on the air curtain-like air flow blown down from the opening 28 may break through the air curtain-like air flow directed vertically downward from the opening 27.
If the air flow blown down from the opening 27 is large, no paint particles will reach the painter, but
If the dimension of d ₁ exceeds twice the size of d ₂ , energy will be lost. According to experiments, when the wind speed of the air curtain-like air flow is 2 m/sec, the widths d ₁ and d ₂ of the openings 27 and 28 are preferably in the range of 20 to 100 mm, respectively, and in particular, d ₁ = d ₂ = 50 mm is optimal. It was hot. _d1 , _d2
If it is less than 20 mm, the air volume can be small, but an air curtain-like air flow cannot be formed all the way to the bottom, and if it exceeds 100 mm, the quality of the coating will be impaired.

In the case of a painting booth in which the object 104 to be painted is an automobile or an automobile body, the width dimension of the object 104 to be painted, which has the largest number of symmetries, is about 1530 to 2190 mm. The horizontal distance between the inner opening 28 provided at the lower end of the ducts 16 and 17 provided at the top of the coating booth and the object to be coated 104 is 35 to 155 mm.
The results of the experiment confirmed that this is good. Then, the respective openings 28, 2 of the distribution devices 26, 26 provided at the lower ends of the ducts 16, 17, respectively.
8, that is, the distance L between the center points of the widths of the openings 28, 28 is expressed as 1600≦L≦2500. For domestic passenger cars, the maximum width is about 1690mm, 1600≦L≦
Represented by 2000. In the above example, L = 1800, but with a vehicle width of 1530 mm to be painted, the distance from the opening 28 is 135 mm, and with a 1690 mm width of the vehicle, the distance from the opening 28 is 55 mm, which improves coating quality, work efficiency, and work environment. There were no problems at all. In addition, in this experiment, when a domestic passenger car was used as the object to be painted, the slope of the side surface of the body was approximately 20 degrees with respect to the vertical, and the opening 28
The best results were obtained when θ was set to 20 degrees, since the air curtain-like airflow blown down from the front flowed along the slope of the side of the body.

FIG. 3 shows another embodiment of the dispensing device. This distribution device 40 includes three molded plate members 41, 42, 43 having a length corresponding to the length of the object 104 to be coated.
are connected by a thin plate-like connecting member 44, and the opening 2 of the ceiling plate 3 is connected by the side edges of the plate-like members 41 and 43.
The opening 47 is airtightly attached to the side wall 15 and is located close to the side wall 15 with the other edge 45 of the plate member 41 and one edge 46 of the central plate member 42 parallel to each other. The air flow supplied from the opening 47 is directed vertically downward as shown by arrow A, and the plate-shaped member 42
The other edge 48 of the plate member 43 and the other edge 49 of the plate member 43 are arranged in parallel to form an opening 50 located closer to the side wall 15, and the air flow supplied from the opening 50 is directed as shown by the arrow. As shown in B, it is oriented so as to be inclined toward the side wall 15 by an appropriate angle within a range of 0 degrees to 50 degrees with respect to the vertical direction. Further, the inner cavity of the distribution device 40 is divided into an opening 47 side and an opening 50 side by a partition plate 51 fixed to the central plate-like member 42 and the connecting member 44, so that interference of flow to the openings 47 and 50 is prevented. prevent. It has been confirmed that the partition plate 51 is not necessary when the airflow velocity is slow.

Inside the opening 47, two guide plates 52, 52 are arranged parallel to the edges 45, 46, respectively.
7 is fixed to the connecting member 44 so as to divide it evenly in the width direction, and the end edges 45, 46
In each of the divided passages, a valve member 53 has one end pivotally supported on the edges 45, 46 or the guide plate 52 by a shaft 54. By remote rotation control, the valve member 53 is rotated to close or open each section passage. Also, inside the opening 50, two guide plates 55, 55 are fixed to the connecting member 44 parallel to the edges 48, 49, respectively, so as to divide the opening 50 equally in the width direction. 49 into three divided passages, and a valve member 56 has one end pivotally supported on the edges 48, 49 or the guide plate 55 by a shaft 57,
By remotely controlling the rotation of the shaft 57, the valve member 56 is rotated to close or open each segmented passage.

In this embodiment, openings 47 and 50 formed in the distribution device 40 are divided into a plurality of divided passages in the width direction by guide members 52 and 55, respectively, and valve members 53 and 56 are rotatably disposed in each divided passage. Since the divided passages can be closed or opened freely, the blowdown position of the air flow in the direction of arrow A or B supplied from each opening 47, 50 to the work space 1 can be adjusted to
It can be changed according to the width of 04. In other words, if the divided passages corresponding to the widthwise center points of the openings 47 and 50 are opened to each other, the work environment will be improved when objects 104 to be coated with different width dimensions are introduced into the coating booth. Painting can be done without changing the surface.

As explained in detail above, in the present invention, an air flow is uniformly supplied into the work space from a chamber formed at the top of the ceiling plate above the work space of the painting booth, and a chamber above the work space is Two air curtain-like air flows are blown down into the work space through the first and second openings of the duct formed independently, and the first opening is located close to the side wall forming the work space. The air curtain-like airflow blown down from the second opening is directed vertically downward, and the air curtain-like airflow blown down from the second opening located further from the side wall is oriented vertically downward.
The first aperture and the second aperture are inclined at an angle of ~50 degrees and directed in a direction proximate to the first air curtain-like airflow, and the first aperture and the second aperture have a spacing between the widthwise center points of each aperture. separated by a distance of 150mm to 350mm,
The width of the second opening is 1/2 to the width of the first opening.
Since the size is three times larger, the paint particles ejected and scattered towards the object to be painted can be moved away from the object to be painted mainly by the air curtain-like air flow formed by the second opening, and This has a synergistic effect with the air curtain-like air flow formed by the openings 1 to quickly descend downward and prevent it from reaching the painter. Furthermore, the distance between the first and second openings is
By setting the width of the second opening to 150 to 350 mm and forming the width of the second opening to be 1/2 to 3 times the width of the first opening,
The airflow of the air curtain blown down from the first and second openings reaches the lower part without interference with each other and turbulence, thereby making it possible to maintain the best working environment.

In addition, in the case where two ducts are arranged in parallel in the present invention, by setting the interval between the center points in the width direction of the second opening formed in each duct to 1600 to 2500 mm, it is possible to When an object to be painted, such as an automobile body, is introduced into a painting booth, it is possible to maintain coating quality and efficiency, and to maintain the best working environment for painting various objects.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of one embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is a sectional view of a modification of FIG. 2. In the figure, 1 is a work space, 3 is a ceiling, 15 is a side wall of the building, 16, 17 are ducts, 20 is an opening in the ceiling, 26, 40 is a distribution device, 27, 28, 4
7 and 50 indicate the openings, respectively.

Claims (1)

[Scope of Claims] 1. In a painting booth in which air is supplied downward from the upper part of a tunnel-shaped working space and is discharged to the outside from the lower part of the working space, a ceiling extending above the working space is provided. means for communicating a chamber formed in an upper part of the board with the discharge side of a blower, and supplying airflow from the blower substantially uniformly downward to the work space through holes formed in the ceiling board; A duct is provided on the discharge side of the blower, the duct being arranged at a predetermined distance from one side wall forming the space, substantially parallel to the side wall, and independent of the chamber formed at the top of the ceiling plate. means for communicating with the duct and supplying an air curtain-like air flow to the work space through an opening formed in the duct, the opening of the duct having a width of the duct in a direction perpendicular to the side wall. The length in the longitudinal direction is significantly increased, and two openings are formed in parallel with each other at intervals in the vertical direction in the side wall, and one of the openings formed in the duct is located at a position closer to the side wall. The first opening is formed by vertically directing an air curtain-like air flow to be supplied from the opening to the work space, and the second opening located at a position farther from the side wall is formed from the opening to the work space. The air curtain-like air flow to be supplied is inclined at an angle of 0 to 50 degrees with respect to the vertical direction and is directed in a direction close to the air curtain-like air flow supplied from the first opening, The opening and the second opening are formed with a distance of 150 mm to 350 mm between center points in the width direction of each opening, and the width of the second opening is set to be the width of the first opening.
An automotive paint booth characterized by being 1/2 to 3 times larger. 2. Either or both of the first and second openings are divided into a plurality of divided passages in the width direction by a guide plate, and each divided passage is configured to be closable by a valve member. An automobile paint booth according to claim 1. 3. In a painting booth where air is supplied downward from the upper part of a tunnel-shaped work space and is discharged to the outside from the lower part of the work space, the air is provided at the top of the ceiling plate stretched above the work space. means for communicating the chamber with the discharge side of the blower, and supplying the airflow from the blower substantially uniformly downward to the work space through holes formed in the ceiling plate; The long and narrow ducts are arranged parallel to each other in the longitudinal direction and spaced apart from each other, and are connected to the discharge side of the blower independently of the chamber formed in the upper part of the ceiling plate, and the ducts are means for supplying an air curtain-like air flow to the work space through formed openings, and the openings formed in each of the two ducts have a length in the longitudinal direction of the duct compared to a width thereof. two openings are formed in each duct in parallel at intervals in the width direction, and of the two openings formed in both the ducts, the first opening is located far from each other. The first openings are formed to vertically direct an air curtain-like airflow supplied from the openings to the work space, and the second openings located close to each other are formed so that the air flows from the openings to the work space are directed vertically. The air curtain-like air flow supplied from the first opening is inclined at an angle of 0 degrees to 50 degrees with respect to the vertical direction, and is directed in a direction close to the air curtain-like air flow supplied from the first opening. , the first opening and the second opening formed in each of the ducts have an interval between center points in the width direction of each of the openings.
The second openings are formed at a distance of 150 mm to 350 mm, and the width of the second openings is 1/2 to 1/2 of the width of the first openings.
A paint booth for an automobile, characterized in that the ducts are formed three times as large, and the two ducts are arranged with a distance of 1600 mm to 2500 mm between the center points of the second openings in the width direction. 4. Either or both of the first and second openings of each duct are divided into a plurality of divided passages in the width direction by a guide plate, and each divided passage is configured to be closable by a valve member. An automobile paint booth according to claim 3, characterized in that: