JPS6212418Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electrostatic coating machine, and particularly to a small and lightweight electrostatic coating machine.

For example, it is necessary for an electrostatic coating machine to be attached to a painting robot or the like to be smaller and lighter in order to reduce the load on the robot arm and enable it to make smaller movements during painting work. However, since a high voltage of about 30 to 100 KV is usually applied to electrostatic atomizers, simply making them smaller and lighter may result in insufficient insulation distance, resulting in high voltage leakage from the high voltage applied part to the grounded part. This results in a decrease in dielectric strength, which is extremely dangerous, and also has an adverse effect on the electrostatic field at the tip of the sprayer body, reducing coating efficiency. Therefore, it is desired to develop a compact automatic coating machine that is smaller and lighter and can perform safe and efficient coating without compromising dielectric strength.

Furthermore, when using conductive paint such as metallic paint, there is a risk that high voltage may leak through the paint to an unexpected location, causing dielectric breakdown or causing an unexpected accident. Therefore, it is desired to develop an electrostatic coating machine that can safely coat even such conductive paints.

Conventional electrostatic sprayers have a paint supply ON/OFF function built into the sprayer itself. Therefore, not only does the main body of the paint sprayer necessarily become larger, but since the ON-OFF function controller is made of metal, it must be sufficiently insulated, and it is necessary to make it smaller and lighter. I was feeling like a stumbling block. Furthermore, if the controller malfunctions, the main body of the paint sprayer must be removed and repaired, which poses a problem in workability.

The present invention was developed in view of the above-mentioned situation.
By removing the OFF function and installing it as a separate unit, the paint sprayer was made smaller.

That is, the present invention separates the paint valve that controls the supply of paint from the paint sprayer body, and installs the paint valve on the back side of the insulating support plate that supports the paint sprayer body, that is, on the side of the support plate opposite to the paint jetting side. It is characterized by being removably attached.

In the present invention, the insulating support plate does not necessarily have to be flat, and may be suitably curved or may have a side wall surrounding the paint valve. The support plate is preferably made of insulating resin such as phenolic resin or epoxy resin, and if necessary, made of plastic reinforced with glass fiber or the like. Further, if a paint passage is provided in the support plate, the insulation distance can be increased by that amount, so that the main body of the paint sprayer can be made smaller.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a side cross-sectional view of a small electrostatic coating machine showing one embodiment of the present invention. In the approximate center of the coating machine body 1 made of an insulating material such as acetal resin, a high voltage cable 2 is connected. The tip end and the high resistance 3 connected to the tip end are sealed with a thermoplastic resin layer 5 made of the same material as the insulating layer 4 of the high voltage cable 2, and then inserted.
It is attached to the coating machine body 1. In addition, at the tip of the high resistance 3, a thermoplastic resin layer 5 is also placed at the tip of the high resistance 3 with a small metal fitting 7 having a lumen in contact with the high resistance 3.
A metal coil spring 8 is inserted into the inner cavity of the metal fitting 7 with its tip portion exposed to the outside of the thermoplastic resin layer 5. An electrically conductive sealing member 9 is located in front of the coil spring 8 and is fixed in the sprayer body 1. A voltage is applied to the needle-shaped charging electrode 11 at the front side of the sealing member 9 via the coil spring 10 provided in front of the sealing member 9 . The sealing member 9 also prevents paint from flowing through a high resistance 3 from a paint flow path 12 in which a coil spring 10 and a needle-like charging electrode 11 extend.
It plays a role in preventing water from penetrating into the sides. On the other hand, a sheath (outer skin) holder 13 is screwed to the rear end of the cable holder 6, and works in cooperation with the sleeve 14 to cover the high voltage cable 2 and to cover the high voltage cable 2 with a grounded conductive or semiconductive material. A sheath (outer skin) 15 is fixed.

In this embodiment, the tip of the high voltage cable 2 and the connection part with the high resistance 3 are completely covered with the thermoplastic resin layer 5, so there is no risk of high voltage leaking therefrom. Therefore, the problem regarding high voltage insulation measures is the most advanced part of high resistance 3,
In the case of this embodiment, since it is sufficient to consider the part where the metal fitting 7 and the coil spring 8 are present as the starting point, the conductive or semiconductive grounded sheath 15 is covered by a distance substantially equivalent to the length of the high resistance 3. The installation position of the sprayer body 1 can be shortened accordingly.
The length is shorter than normal.

A paint atomizing air supply path 16 is further formed in the paint sprayer body 1, and compressed air supplied through this passes through a connecting air path 17 to an annular atomizing compressed air jet. The paint ejected from the outlet 18, passed through the paint channel 12, and discharged from the paint discharge hole 19 is atomized, and the atomized paint is charged by the needle-shaped charging electrode 11. Furthermore, another air supply passage (not shown) is bored in the sprayer main body 1 in parallel with the air supply passage 16, and the compressed air supplied from this air supply passage is
The air is ejected through the two air passages 20, 20' from the air injection holes 21, 21' for adjusting the coating pattern, changing the coating pattern of the coating machine from a round pattern to a flat pattern, that is, changing the coating pattern of the coating machine from a round pattern to a flat pattern, that is, spraying the atomized paint from the coating machine. Try to regulate and adjust the direction.

The coating machine body 1 is fixed to an insulating support plate 22 with mounting screws 23, and is further fixed to an arm 25 of the painting robot via an insulating fixing base 24 with fixing bolts 2.
It is fixed at 6. The arm 25 is made of metal in order to firmly hold the coating machine, and the fixing bolt 26 is also often made of metal because it is required to have considerable strength. The arm 25 is normally grounded, and especially when a small electrostatic sprayer is used as in the case of the present invention, the distance between the tip of the sprayer and the arm 25 and fixing bolt 26 is shortened. If there is a grounded object near the needle-like charged electrode 11 at the tip of the paint sprayer to which a high voltage is applied, it may adversely affect the composition of the electrostatic field, resulting in a decrease in coating efficiency, or the grounded object may Since paint often adheres and contaminates the equipment, it is preferable to cover the fixing bolt 26 with an insulating cap 27 for shielding as in this embodiment.

In the present invention, a metering valve (paint valve) 29 is removably attached to the back surface 28 of the insulating support plate 22 for controlling ON/OFF of paint supply. A paint supply pipe (both not shown) from a paint supply source is connected to the paint inlet 30 of the metering valve 29, and a paint outlet 31 located at the bottom of the metering valve 29 is bored in the support plate 22. A paint supply pipe 33 communicating with the paint flow path 12 is connected through a paint passage 32 . Many of the metering valves 29 are made of metal, so when they are charged, the accumulated charge can instantly discharge and cause spark discharge, which is dangerous, so they are usually grounded. The back side 2 of the insulating support plate 22
8, the support plate 22 acts as an insulating shield for the needle-shaped charged electrode 11 at the tip of the sprayer to which high voltage is applied, so that the tip of the sprayer and the metering valve 29 can be connected to each other. This makes it possible to shorten the distance between the two, which is very useful in making the coating machine itself more compact.

In addition, when using conductive paint such as metallic paint, in order to ensure insulation, it is necessary to connect the paint supply path from the paint flow path 12 to which high voltage is applied to the grounded metering valve 29. The distance, that is, the length of the paint supply pipe 33, is required to be longer than a predetermined value (100 mm or more, preferably 150 mm or more). ON for road and paint supply
-A paint passage 32 without an OFF mechanism and bored through the paint supply pipe 33 and inside the insulating support plate 22 by a separately provided metering valve 29.
By supplying the paint through the paint, it is possible to maintain a sufficient insulation distance for the paint supply path even though the main body 1 of the paint sprayer is downsized. There are no problems when using the paint. The paint passage 32 may not be provided in the support plate 22, and the paint supply pipe 33 may be directly connected to the metering valve 29.

Furthermore, as shown in FIG.
9 makes it easier to reduce the insulation distance of the paint supply path, that is, the length of the paint supply pipe 33, even though the sprayer main body 1 is made smaller and the tip of the sprayer and the metering valve 29 are brought closer together. This is advantageous because the paint supply pipe 33 can maintain its own shape even when the paint machine is moved for painting work.

The present invention has been described above with reference to an example of an air atomizing electrostatic atomizer that is attached to a painting robot, etc., but the present invention is not limited to the above example, and can be applied to automatic, hand-held, and air atomizing types. It can be suitably applied to various electrostatic atomizers such as a hydraulic atomizer, an electrostatic atomizer, and an electrostatic atomizer.

As mentioned above, in this invention, the paint valve is not built into the sprayer body, but is installed in a separate location, making it possible to reduce the size and weight of the sprayer body. Since it is mounted on an insulating support plate, it is possible to avoid the inconvenience of the relative positional relationship between the paint valve and the sprayer body changing depending on the movement of the robot when it is mounted on a robot or the like. In addition, in this invention, the paint valve is attached to the back of the insulating support plate, so even if the paint valve is grounded, the discharge electrode at the tip of the paint sprayer body, which is the high voltage application part, and the paint, which is the ground conductor, will be connected. Since there is an insulating wall between the valve and the valve, the distance between the two can be shortened due to the insulating effect of the support plate, and the overall size of the atomizer can be reduced. The support plate also serves as a shielding plate for the ionic current and charged paint particles flowing from the discharge electrode to the paint bulb, greatly contributing to safety and stain prevention during painting. Since the paint valve is removably attached to the support plate, only the valve can be separated for replacement or maintenance, which is advantageous in terms of work and has many other excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of the coating machine of the present invention, and FIG. 2 is a front view of the same embodiment. In the figure, 1... Painter main body, 2... High voltage cable, 3... High resistance, 4... Insulating coating layer, 5... Thermoplastic resin layer, 6... Cable holder, 7... Metal fittings, 8 ...Coil spring, 9...Sealing member, 11...
...Acicular charged electrode, 12...Paint flow path, 22...Insulating support plate, 29...Metering valve, 33
...Paint supply pipe.

Claims (1)

[Scope of utility model registration request] A small automatic electrostatic coating machine characterized by a paint valve for controlling the supply of paint being removably attached to the back of an insulating support plate that supports the coating machine body.