JPH04200758A - Grid electrode apparatus of rotary atomizing type electrostatic painting machine - Google Patents

Abstract

PURPOSE:To provide a small-sized lightweight grid electrode apparatus easy to handle and ensured in working safety by embedding a ring-shape conductor in a cylindrical main body, and performing the attachment of a power cable to a connection hole and the attachment of grid electrode elements to respective mounting holes through stress cones in a freely detachable manner. CONSTITUTION:A connection hole 14 for a power cable 4 is provided to the rear end surface of the cylindrical main body 11 of an insulator and the mounting hole 15 for each grid electrode element 41 is provided to the leading end surface thereof and the groove 16 for embedding a ring-shape conductor 21 is provided to the part between the connection hole 14 and the mounting hole 15. The power cable 4 for supplying a current to the grid electrode element 41 is connected to the connection hole 14 of the cylindrical main body 11 through a stress cone, and the grid electrode element 41 for charging the aqueous paint P2 atomized by a bell 3 is attached to each mounting hole 15 of the cylindrical main body 11 through a strain cone and constituted of an insulating cylindrical body 42, a current-limit resistor 43 and a discharge pin 44.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grid electrode device for a rotary atomizing electrostatic coating machine.

[Prior Art] FIG. 4 shows a schematic configuration of a grid electrode device IA of a conventional rotary atomizing electrostatic coating machine.

Conventionally, rotary atomization type q? = Is this a coating machine that uses a grid electrode device IA to negatively charge the paint P that is atomized by the bell 3 rotating in a predetermined direction and attaches it to the object to be painted (not shown) on the positive electrode side (earth side)? It is often used for painting automobile bodies, etc. because of its high coating efficiency.

Such an electrostatic coating machine generally includes a bell support 2 and a grid electrode device IA attached to the bell support 2.

Specifically, the bell 3 is rotatably supported on the bell support 2 via a hollow shaft 8, as shown in FIG. This hollow shaft 8 is rotatably attached to the bell support 2 via an air bearing 8A, and is configured to be driven to rotate at a high speed of 20,000 to 6.000 RPM by an air turbine 8B. Further, a paint supply pipe 6 is inserted into the hollow shaft 8 in a non-contact manner, and from this material supply pipe 6 paint P flows through the hollow shaft 8 along the axis 9 and is supplied to the bell 3. has been done. In addition, the above-mentioned bell support 2. The bell 3 and the paint supply pipe 6 are grounded.

On the other hand, the grid electrode device IA includes a plurality of (for example, six) grid electrode elements 41A arranged so as to surround the bell support 2 via an electrically insulating cylindrical body 11A. As shown in FIG. 5, each grid electrode element 41A has an insulating cylindrical body 42. It consists of a current limiting resistor 43 and a discharge pin 44, and is insulated and bonded to the cylindrical body 11A.
has been done. This grid electrode element 41A (current limiting resistor 43) is connected to a high voltage (for example, -40 to 80 KV).
) is connected by a conductive adhesive K.

In addition, 7 in FIG. 5 is an insulating protection tube, which connects the power supply cable 4 and the grid to the pole element 41A (43) (
K) and the grounded bell support 2 to prevent high voltage leakage. Letting the length of the protective tube 7 be D and the distance from the bell support 2 to be D, basically, if L is increased, D can be decreased, and if L is decreased, D must be increased.

By the way, the paint P includes an organic solvent-based paint that uses thinner etc. as a solvent, and a water-based paint that uses water as a solvent or solvent (water-soluble, water-based).
There is a paint P2. The organic solvent-based paint is rich in electrical insulation, and the water-based paint P2 is rich in conductivity.

So, if using an organic solvent-based paint, is it okay to use the direct charging method, or in the case of water-based paint f4P2, the paint supply pipe 6?
Because of the grounding, it is not possible to use a direct charging method, so it is preferable to use a grid electrode method. It is understood that when applying the water-based paint P2 using the grid electrode method, the insulation between the connection part and the bell support 2 must be further ensured.6 For example, the application electrode of the grid electrode element 41A must be If the voltage is 180KV, the above is 250 to 30
It is necessary to take measures such as setting it to 0 mm.

However, in actual operation, water-based paint P2 is used only for specific paint colors, and most of the time organic solvent-based paints are used, and in the case of organic solvent-based paints, the direct electrification method is not used. Even if there are some drawbacks to the Kurisode electrode method, the water-based paint P2
The actual situation is that the installation locations and number of installations were limited, so its shortcomings were not carefully examined and left as they were.

However, in recent years, as the demand for pollution prevention has become even stronger, the use of paints that use organic solvents such as thinner has tended to be restricted from the viewpoint of the VOC system, and water-based paint P2, which is based on water, has suddenly attracted attention. Development of paints for this purpose is also becoming more active. Therefore, it is thought that the usage ratio of organic solvent-based paint and water-based paint P2 will be reversed in the near future.

[Problems to be Solved by the Invention] Thus, when we examine in detail the case of using water-based paint P2 using the grid electrode method, which will become mainstream in the near future, we find that the conventional structure described above has the following specific problems. There are certain shortcomings.

(D) The length of the protective tube 7 is quite large, and the distance between it and the bell holder 2 is also quite large, at 250 to 300 mm. Therefore, when arranging a large number of grid electrode type devices, it is necessary to 6 Furthermore, in order to prevent accidents due to electric field concentration at the connection part, dielectric breakdown, etc., it is necessary to have a sufficient dimension and D, which requires a drastic reduction in device size. 6 ■ Also, it is impossible to completely prevent high voltage leaks only by taking measures such as the dimensions and D mentioned above, as electrical pinholes may occur at the bonded part J, etc. Therefore, it is dangerous when workers approach or touch it.

■ Due to the requirements of ■ and ■ above, it is necessary to carefully assemble each adhesive part J, so grid S'/Ijl element 41A
Not only the assembly work but also the replacement work requires a lot of labor and time and is troublesome. Furthermore, since the high voltage power supply cable 4 is provided for each grid electrode element 41A, the wiring process is complicated and becomes a factor in increasing the size of the device. It is also difficult to attach and detach the power supply cable 4 itself.

The present invention has been made in view of the above circumstances, and its object is to provide a grid electrode device for a rotary atomizing static coating machine that is small, lightweight, easy to handle, and ensures work safety, and can efficiently apply water-based paints. Our goal is to provide the following.

Means for Solving the Problem] The present invention has a ring-shaped conductor embedded in a cylindrical body having one connection hole provided on the rear end side and a plurality of attachment holes provided on the front end side. A power supply cable for supplying power to the ring-shaped conductor is connected to the connection hole via a stress cone, and a grid electrode element consisting of an insulating cylinder, a current limiting resistor, and a discharge pin is connected to each of the mounting holes. It is characterized by being removably attached via a stress cone.

[Function] In the present invention, a plurality of grid@pole elements are removably attached to each attachment hole of one cylindrical body via stress cones. Further, each grid electrode element is connected to one power supply cable via a ring-shaped conductor embedded in the cylindrical body. This power supply cable is connected to the connection hole of the cylindrical body via a stress cone.

This completely insulates the main source of leakage, the attachment part of the clean electrode element and the connection part of the power supply cable. In addition, the wiring process for the power supply cable is simplified, making it possible to reduce the size and weight and improve work safety.

Once upon a time, it was possible to prevent leaks and apply water-based paints smoothly and with high efficiency using a simple configuration.

[Example] An example of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 is a cross-sectional view of one side showing the overall configuration, FIG. 2 is a view showing one half of the right side surface, and FIG. 3 is a view showing one half of the left side surface.

Components that are the same as those shown in FIG. This is a means for arranging the grid "r:&IE elements 41 (6 pieces in the example) with a predetermined positional relationship. Specifically, the cylindrical main body 11 is made of an insulator, and the rear end surface 1211II The connection hole 14 for the power supply cable 4 is 1
There are several. Further, the tip surface 13 of the cylindrical main body 11
On the side, mounting holes 15 for each grid/y grid electrode element 41 are provided in the same number as the electrode elements 41 (six in this embodiment).

Further, a groove 16 for embedding the ring-shaped conductor 21 is provided in a portion of the cylindrical body 11 between the connection hole 14 and the attachment hole 15.

Further, the ring-shaped conductor 21 is a means for enabling power to be supplied to each grid electrode element 41 with one power supply cable 4 in order to simplify the wiring process of the power supply cable 4. Specifically, the ring-shaped conductor 21 is embedded in the groove 16 of the cylindrical body 11, and each of the ring-shaped conductors 21 is connected to the pole element 4.
1 and are connected via lead wires 5 and the like. The ring shape may be a continuous ring shape or a shape with a portion cut away. Note that the tube 16 is configured to be filled and sealed with an insulating filler 17 after the ring-shaped conductor 21 is buried therein.

Furthermore, the power supply cable 4 is a means for supplying power to the grid electrode element 41, and the connection hole 14 of the cylindrical body 11
is connected to via a stress cone 31.

On the other hand, the grid electrode element 41 is a means for charging (negatively charging in this embodiment) the water-based paint P2 atomized by the bell 3, and is connected to each mounting hole 15 of the cylindrical body 11 via the stress cone 32. It is removably attached. Specifically, the grid electrode element 41
2, a current limiting resistor 43, and a discharge pin 44;
For example, it is limited to 500 μA or less.

Next, the effect will be explained.

A plurality of (six) grid electrode elements 41 are removably attached to each attachment hole 15 of the cylindrical main body 11 via the stress cone 32. In addition, each grid electrode element 4
1 is a ring-shaped conductor 21 embedded in a cylindrical body 11;
It is connected to one power supply cable 4 via a cable or the like. This power supply cable 4 is connected to the connection hole 14 of the cylindrical main body 11 via a stress cone 31.

As a result, the attachment portion of the grid electrode element 41, which is a major source of leakage, and the connection portion of the power supply cable 4 are completely insulated. Further, the wiring process for the power supply cable 4 is also simplified.

As a result, leakage can be completely prevented with a simple configuration, the water-based paint P2 can be smoothly charged, and highly efficient painting can be performed.

According to this embodiment, the insulating cylindrical body 11
A ring-shaped conductor 21 is embedded in the stress cone 3, and each grid electrode device 41 and power supply cable 4 are connected to the stress cone 3.
Since it is configured to be removably attached to the mounting hole 15 and the connection hole 14 through 2.31, high voltage leakage to the bell support body 2 can be completely prevented, and handling such as assembly and disassembly work is easy and easy. Safety is also guaranteed. Therefore, the conductive water-based paint P2 can be applied smoothly with high efficiency.

In addition, since leakage can be completely prevented using the stress cones 31 and 32, the distance (D) between the connecting portion of the high voltage power supply cable 4 and each grid electrode element 41 and the bell support 2 can be kept at 100 mm or less. It is also possible to set it to 10 mm or less depending on the type of stress cone, etc. Moreover,
The long (L) conventional protection tube 7 is no longer necessary. I wanted to,
Significant reduction in size and weight has been achieved, and a large number of devices can be placed adjacently in a small space.

Further, since only one power supply cable 4 is required, the wiring process can be greatly simplified, and the -stage can be made smaller, lighter, and lower in cost.

Further, the ring-shaped conductor 21 is supplied with a high voltage from one power supply cable 4 and has a plurality of grid electrode elements 4.
1 can be installed, so it has great applicability.

[Effect of the invention 1] According to the present invention, a ring-shaped conductor is embedded in a cylindrical body having one connection hole provided on the rear end side and a plurality of attachment holes provided on the front end side, and the ring-shaped conductor is connected. A power supply cable for supplying power to the ring-shaped conductor is connected to the hole through the stress cone, and a grid t[i element consisting of an insulating cylinder, a current limiting resistor, and a discharge pin is connected to the hole through the stress cone. Since it has a structure in which it can be attached and removed freely, it has a simple structure, is small and lightweight, and is easy to handle. It also completely prevents leaks, guarantees work safety, and enables highly efficient and smooth application of water-based paints. .

[Brief explanation of the drawing]

1 to 3 are diagrams showing a schematic configuration of an embodiment of the present invention, and FIG. 1 is a half-sectional view showing the entire configuration. FIG. 2 is a diagram showing one half of the right side, and FIG. 3 is a diagram showing one half of the left side. Figures 4 to 6 are diagrams showing the general configuration of a conventional rotary atomizing paint sprayer, with Figure 4 being an overall configuration diagram, and Figure 5 being a diagram for explaining the mounting state of grid electrode elements and 6 is a diagram for explaining the internal configuration. 61...Grid electrode device, 6...Paint supply pipe, 8...Hollow shaft, 11...Cylindrical body, 12...Cylindrical shape Rear end surface of main body, 13... Top surface of cylindrical main body, 21... Ring-shaped conductor, 31.32... Stress cone, 41... Grid electrode element, 42... Insulating cylinder, 43... Current limiting resistor, 44... Discharge pin. Applicant: Trinity Industries Co., Ltd.

Claims (1)

[Claims] (1) A ring-shaped conductor is buried in a cylindrical body having one connection hole provided on the rear end side and a plurality of attachment holes provided on the front end side, and the ring-shaped conductor is inserted into the connection hole. A power supply cable for supplying power to the body is connected via a stress cone, and a grid electrode element consisting of an insulating cylinder, a current limiting resistor, and a discharge pin is detachably attached to each of the mounting holes via the stress cone. A grid electrode device for a rotary atomizing electrostatic atomizer featuring: