JPH0659429B2 - Liquid spray pattern forming method and spray device - Google Patents

Description

The present invention relates to a method for forming a spray pattern in electrostatic spray coating of a liquid and a spray device therefor. The liquid refers to a liquid paint, a heat-melted resin, a non-volatile liquid, an oil or fat.

In addition, the present invention is implemented by the present applicant on April 1, 1985.
It is an applied invention based on the date patent application "Method of forming spray pattern of powder coating material and spray device thereof". That is, in the above-mentioned invention, the powder coating is mainly intended, but by the subsequent experiments, the same as the above-mentioned basic invention is applied to the liquid coating and the heat-melting resin, other non-volatile liquids, fats and oils. Since it has been confirmed that the effect can be obtained, the present invention is modified so as to be applicable to these various liquids.

Conventionally, the shape and size of a spray pattern and the distribution density of liquid particles in electrostatic spray coating of a liquid have been determined by the characteristics of each fluid, the design of its ejection port, its processing accuracy, and the like. Therefore, the applicator prepared a large number of various ejection ports (nozzles and air caps) so as to be able to correspond to each pattern. Not only are these expenses not small, but also in using them, It took a lot of time and effort to make a selection. Furthermore, minute adjustments were almost impossible. Therefore, they have performed inefficient work.

The motivation for the present invention was to solve these problems.

An object of the present invention is to provide a method and an apparatus for further expanding the spray pattern when spraying a liquid so that the particles of the liquid are more dispersed and the distribution density is made more uniform.

The gist of the present invention is to eject a liquid outward from a plurality of ejection ports attached to each other outward,
The resulting blank portion formed between a plurality of applied spray patterns within a relatively wide span or range is caused by the action of the electrostatic charging electrode provided in the middle portion of the plurality of jet outlet groups. To attract the particles of the ejected liquid, thereby filling the blank part of the plurality of spray patterns to form a relatively wide spray pattern, and the applied voltage to the electrostatic charging electrode and the discharge amount of the liquid. The method of forming a desired spray pattern by adjusting the shape and coating distribution density of the spray pattern, the thickness of the coating film, etc. by adjusting the above and the like and a spray device for performing the method.

The target liquid of the present invention includes various liquid paints such as general liquid paints, water dispersions, powder slurry type paints, other heat-meltable resins, non-volatile liquids, and fat / parade slurry. Various paints such as molds, other heat-meltable resins, various non-volatile liquids, fats and oils, etc.

Next, the method of the present invention will be described. Before that, the principle of electrostatic liquid application will be briefly described. Spout (nozzle)
The particles of the liquid sprayed more are first attracted and charged by the relatively strong lines of electric force generated around the electrostatic charging electrode provided in the vicinity of the ejection port, and then toward the object to be coated. It is something that can be rushed and attached. In order to perform the above action, it has been customary in the past to use one electrostatic charging electrode for one ejection port.

The present invention uses an electrostatic charging electrode in the middle of a plurality of ejection ports.

The method according to the invention is explained by means of the drawing. See FIG. First, the liquid is discharged from a plurality of jet outlets 8A, 8B which are communicated with a plurality of convergent-coupled ejectors 1, 2 and which are attached outward at a required angle α, β. Spray SA towards the direction,
SB is done. The spray pattern is, as shown in FIG. 2A, a plurality of eyeglass-type spray patterns Pa and P.
b, and there is a blank part between them.

However, when a voltage is applied to the electrostatic charging electrode 10 provided in the middle portion of the jet nozzles 8A and 8B, as described above, the sprayed airborne liquid particles SAp and SBp.
Is attracted toward the line of electric force by the action of the line of electric force described above. Then, the blank portion between the eyeglass-type spray patterns is filled, and the two spray patterns are connected as shown in FIG. 2B. However, the filling amount depends on the strength of the voltage applied to the electrostatic charging electrode. That is, the shape of the pattern is P in FIG. 2B.
It changes like ₁ , P ₂ . Further, the coating distribution density and the thickness of the coating film can be changed by the strength of the voltage. In this way, a desired spray pattern can be formed.

In addition, in forming the spray pattern, the characteristics and discharge amount of the fluid as well as the hole diameter, shape, and angle of the ejection port,
The ejection pressure of the spray gas is also a factor.

Of the various spray patterns created in this way,
Here are some basic examples.

Spray pattern example 1. When a voltage is applied to an electrostatic charging electrode (hereinafter abbreviated as an electrode) for two circular spray patterns Pa and Pb of equal size as shown in FIG. 2A,
Different spray patterns such as P ₁ and P ₂ shown in FIG. 2B are formed depending on the strength of the voltage.

Spray pattern example 2. As shown in FIG. 3A, when a voltage is applied to the electrodes with respect to the two large and small circular spray patterns Pc and Pd, P ₄ and P ₄ shown in FIG.
Different spray patterns are obtained, such as P ₅ .

Spray pattern example 3. As shown in FIG. 4A, when a voltage is applied to the electrodes with respect to spray patterns Pe and Pf in which two strips are arranged vertically, spray patterns such as P ₆ and P ₇ shown in FIG. The pattern is obtained.

Spray pattern example 4. As shown in FIG. 5A, spray patterns Pg, Ph, Pj in which three circles are arranged at three corners
On the other hand, when a voltage is applied, a mountain shape is formed as shown in FIG. 5B.

Spray pattern example 5. As shown in FIG. 6A, spray patterns Pk and P in which four circles are arranged at each corner of a square
When a voltage is applied to l, Pm and Pn, it becomes a quadrangle as shown in FIG. 6B.

By combining these, various large and small spray patterns can be obtained. In this way, for the size and shape of the object to be coated, a desired shape spray pattern can be obtained relatively easily and inexpensively without designing and producing a special spray nozzle as in the past. The coating density can be adjusted and made uniform, and the liquid can be coated with less overspray and with high coating efficiency.

Next, a spray device for obtaining a spray pattern as described above will be described. First, the case of using two jet ports, which is the basic structure, will be described. See FIGS. 7 and 8. The two dispensers 1, 2 are mounted on a hinged dispenser mount. Two ejectors 1 and 2 are mounted on the two hinge plates 3 and 4 in opposite directions, and an electrostatic charging electrode holder 9 is indirectly connected to an intermediate portion of these hinge plates. Further, female screws 7 are provided on both end members of these hinge shafts, and the opening of the hinge plate is fixed at a predetermined position by tightening them.

There are various other ways to attach the dispenser to the hinge plate, and two rows are shown below. One of them is, as shown in FIG. 9, a method of attaching the dispensers 1A and 2A back to back,
The other is a method of mounting the dispensers 1B and 2B on the hinge shaft 5B as shown in FIG. In each case, the hinge opening is of an arbitrary fixed type by means of nuts 7A, 7B and the like, and the electrostatic charging electrode holder 9A,
9B is provided.

Next, the structure when the intermediate adapter is provided between the discharger and the ejection port will be described. Please refer to FIG. 11 first. Two spouts 1 are provided below one intermediate adapter 11.
8A and 18B are directed outward at angles α and β on the center line of the intermediate adapter 11, and are attached via the respective jet outlet attachment fittings 12A and 12B. Dischargers 21 and 22 corresponding to the above-mentioned two ejection ports are attached on both upper side surfaces of the intermediate adapter 11. In the intermediate adapter 11, liquid passages 24F and 26 that connect the ejector and the ejection port to each other.
The pressurized air passages 24A and 26A for F and spray are guided in parallel to the ejection port attachment fittings 12A and 12B, respectively. In addition, electromagnetic actuating valves 29A and 29B, or air actuating valves instead of them, are attached to the discharger, as in the conventional device. Also, the lower surface of the intermediate adapter,
That is, an electrostatic charging electrode 20 is provided between the two ejection ports 18A and 18B, and the electrode is a high-voltage static electricity generator H.H. V. It is connected to G. Note that FIG. 12 is shown in the "A" arrow view as in FIG.

Although FIG. 11 shows a side view of the two-fluid spray device, it has been tested that the present invention can be applied to an airless spray device. In that case, the pressurized air C for spraying the dischargers 21 and 22 shown in FIG.
The air pipe of A is deleted, but the return pipe for the fluid is added. As described above, the structure of the discharger itself in the airless spray device is slightly changed, but the basic principle and operation are exactly the same, and the present invention can be applied to the airless spray without any problem. .

The above shows the case where there are two ejection ports, but FIG. 13 shows a view from the arrow "A" when there are three ejection ports, and FIG. 14 when there are four ejection ports. Further, FIG. 15 shows two jet nozzles with slit nozzles attached.

As described above, when a plurality of jet outlets and their dischargers are paired together, the jet amount of each jet can be adjusted. However, when it is not necessary, the effect according to the present invention as described above can be obtained by using one ejector and attaching a plurality of ejection ports to it. A side view of the spray device is shown in FIG. That is, the two ejection ports 58A and 58B are provided on the lower surface of one discharger 51, and the required angles α and β are provided.
Attached to the outside, and at the middle portion (on the center line in the figure) of these ejection ports, the electrostatic charging electrode 6
0 is provided. Inside the discharger, a passage 53 for introducing one liquid, two liquid passages 53A and 53B branched therefrom, and one passage 54 for introducing pressurized air for spraying, And the two pressurized air passages 54A and 54B branched from each other, the two fluids are respectively guided in parallel to the ejection port mounting fittings 52A and 52B, and the respective ejection ports 58A and 58B are mounted to these fittings. Has been. Further, it is preferable that the jet outlet fitting has a variable angle structure, and as an example thereof, FIG. 17 shows a spherical joint type jet outlet fitting.

The liquid targeted by the present invention is mainly a liquid coating material, but other heat-fusible resins containing no solvent are also applicable. For example, it is a case of surface application of an adhesive.
It can also be applied in the case of surface application of oils and fats for the purpose of rust prevention. In addition, it is also suitable when a non-volatile chemical solution or the like is applied over the surface.

As described above, according to the method and apparatus of the present invention, a spray pattern having a relatively wide span or range and a uniform distribution density and a more complicated shape can be obtained under micropreparation. Therefore, it is possible to perform spray coating work of various liquids that match the shape and size of the object to be coated. Furthermore, since overspraying of liquid particles can be suppressed to a minimum, it is possible to contribute to resource saving.

[Brief description of drawings]

FIG. 1 is an explanatory view of the action of an electrostatic charging electrode according to the present invention (hereinafter, abbreviated to the one according to the present invention).
The figure shows a spray pattern when static electricity is not applied in the spray pattern example 1. FIG. 2B is the same as above. A spray pattern when static electricity is applied is shown in FIG. 3A. A spray pattern when no static electricity is applied in the spray pattern example 2 is shown in FIG. 3B. Spray pattern when static electricity is applied. FIG. 4A is a spray pattern when static electricity is not applied in spray pattern example 3. FIG. 4B is the same as above. Spray pattern when static electricity is applied. FIG. 5A is a spray pattern when static electricity is not applied in spray pattern example 4. Pattern FIG. 5B is the same as above but spray pattern when static electricity is applied. FIG. 6A is the spray pattern when no static electricity is applied in spray pattern example 5. FIG. 6B is same as above and spray pattern when static electricity is applied. FIG. 8 is a side view of the apparatus. FIG. 8 is a plan view of the same as above. Plan view of Figure 10 hinged sprayer plan view attached to Align the hinged sprayer fitted with a dispenser on the hinge shaft first
Fig. 1 is a side view of the spray device in the case where an intermediate adapter is provided between the discharger and the jet port. Fig. 12 is the same as the above figure "A" arrow view. Fig. 13 is "the case where three jet ports are attached." A ”
Arrow view Figure 14 is an "A" arrow view when four spouts are attached Figure 15 is a state view when the slit nozzle is attached in Figure 12 Figure 16 is a multiple branch inside the dispenser FIG. 16 is a side view of a case where a passage is provided. FIG. 16 is a partial cross-sectional view of a spherical joint type jet outlet mounting bracket with a variable angle mounted on an intermediate adapter or a dispenser. Description of main symbols 1, 2, 21, 22 , 31, 32, 33, 41, 42,
43, 44, 51 ... Discharger, 3, 4 ... Hinge plate, 8
A, 8B, 18A, 18B, 28A, 28B, 38A,
38B, 38C, 48A, 48B, 48C, 48D, 5
8A, 58B, 68A, 68B ... Spouts 10,2
0, 40, 50, 60 ... Electrostatic charging electrode, 11, 3
5,45 ... Intermediate adapter, 12A, 12B, 52A,
52B ... Jet outlet fittings, 65A, 65B ... Spherical joint type jet fittings, CA ... Pressurized air, F ... Fluid, Pa, Pb, ..., Pn ... Spray pattern when no static electricity is applied , P ₁ , P ₂ , ..., P ₉ ... spray pattern when static electricity is applied, SA, SB ... particles when liquid is sprayed, SAp, SBp ... particles to which static electricity of liquid is applied

Claims (9)

[Claims] 1. In electrostatic spray coating of liquid, the liquid is jetted outward from a plurality of jet outlets (8A, 8B) at a required angle (α, β), and thereby desired. A plurality of spray patterns are obtained within a wider span or a desired wider range, and the jetting is performed by the action of the electrostatic charging electrode (10) provided in the middle portion of the plurality of jet outlet groups. The plurality of spray patterns are attracted by attracting liquid particles, filling a blank portion generated between the plurality of spray patterns, and adjusting the applied voltage to the electrostatic charging electrode and the discharge amount of the liquid. A method for forming a liquid spray pattern, which comprises forming a desired spray pattern by adjusting a degree of filling a blank portion between the two. 2. The liquid is a liquid paint or a hot-melt resin,
The method for forming a spray pattern of a liquid according to claim 1, which is a non-volatile liquid or oil. 3. The method for forming a spray pattern of a liquid according to claim 1, wherein the spray is a two-fluid spray or an airless spray. 4. In a liquid electrostatic spray coating device,
The two dispensers (1,2) are hinged dispenser fittings (3,3).
4), and a holder (9) for the electrostatic charging electrode (10) is attached to the center of the hinge shaft (5) of the dispenser attachment, and the opening degree of these hinges Is a spray device for forming a spray pattern of a liquid, which is fixed in place by a nut (7). 5. The liquid according to claim 4, wherein the ejection ports (68A, 68B) are attached to the main body of the ejector (1, 2) by means of variable direction angle ejection port attachment fittings (65A, 65B). A spray device that forms a spray pattern. 6. A liquid electrostatic spray coating device comprising:
A plurality of liquid ejectors (21, 22) are respectively mounted on different surfaces of one intermediate adapter (11), and liquid passages (23F, 25F) in these ejectors are attached.
And, the pressurized air passage for spraying (23A, 25A) is connected to the jet fitting (12A, 12B) via the liquid passage (24F, 26F) and the pressurized air passage (24A, 26A) in the intermediate adapter. Further, they are communicated with the jet outlets (18A, 18B) attached to the tip of the metal fitting, and these jet outlets have the necessary angles (α, β) with respect to the center line of the intermediate adapter. A spray device for forming a spray pattern of a liquid, characterized in that an electrostatic charging electrode (20) is provided substantially in the middle of the plurality of ejection port groups. 7. The liquid according to claim 6, wherein the jet ports (68A, 68B) are mounted on the intermediate adapter (11) by the direction angle variable jet port fittings (65A, 65B), respectively. A spray device for forming a spray pattern. 8. A liquid electrostatic spray coating device comprising:
In one liquid ejector (51), one liquid passage (53) and one spray pressurized air passage (5) are also provided.
4) and each branch into a plurality of lines (53A, 53B; 5)
4A, 54B), the branched two-fluid passages are guided in parallel, and the jet outlets (58A, 58B) are attached to the end portions of the respective passages, and these jet outlets are connected to each other. The liquid is characterized in that it is directed outward at respective required angles (α, β) with respect to the center line, and further, an electrostatic charging electrode (60) is provided at approximately the middle portion of the ejection port group. A spray device that forms a spray pattern. 9. The liquid spray pattern according to claim 8, wherein the jet ports (68A, 68B) are attached to the dispenser main body by means of variable direction angle jet port attachments (65A, 65B). Spray device.