JPH0636889B2 - Air atomization type electrostatic painting gun - Google Patents

Description

The present invention relates to an air atomization type electrostatic coating gun.

[Conventional technology]

Air atomization type electrostatic coating gun (hereinafter simply referred to as coating gun)
As is well known, the basic structure of the paint is a high voltage applying part for paint charging, which has a needle-shaped electrode protruding from the paint injection hole at the tip of the coating gun,
A paint atomization air injection hole and a pattern formation air injection hole for atomized paint are arranged in the vicinity of the paint injection hole, and the main body of the coating gun houses a high voltage supply section that conducts to the high voltage application section for paint charging.
In addition, a paint supply path for supplying paint to the high-voltage applying section for paint charging, a paint atomizing air injection hole, and an air supply path for supplying compressed air to the pattern forming air injection hole of the atomized paint are formed, and the base of the main body of the coating gun. Grounded switch that opens and closes the electric circuit of the high-voltage supply unit and the high-voltage supply cable by a trigger, the grounded paint valve that opens and closes the paint circuit of the paint supply passage and the paint supply hose, the air supply passage and the air supply. The structure is such that an air valve that opens and closes the air circuit of the hose is arranged.

And the coating gun that uses metallic paint, because metallic paint has low viscosity and low paint resistance,
While the paint gun is moving, electricity leaks from the paint supply path that flows the paint to an unexpected place, causing insulation breakdown,
Alternatively, when the coating gun is brought close to a grounded object other than the object to be coated, the metallic pigment in the metallic paint flowing in the paint supply passage of the coating gun forms a chain state,
The high voltage applied and supplied to the electrodes escapes to the grounded paint tank, and a so-called bridging phenomenon that electrostatic coating cannot be performed easily occurs.

In order to eliminate the inconvenience, one example in which the flow distance of the metallic paint flowing in the paint supply passage arranged in the coating gun is increased to increase the resistance of the metallic paint to eliminate the inconvenience, This is the invention disclosed in Japanese Utility Model Publication No. 45357. Other examples in which a paint supply passage wound in a coil shape is attached to the outside of the coating gun to increase the flow distance of the metallic paint and increase the resistance of the metallic paint to eliminate the inconvenience are described in U.S. Pat.
It is disclosed in Japanese Patent No. 4,139,155.

However, with the former structure, the distance of the paint supply passage cannot be made sufficiently long. In the latter structure, the former defect can be eliminated, but since the paint supply path is arranged outside the paint gun, there is a risk of causing a dielectric breakdown phenomenon at an expected place and causing an accident.

In order to solve these drawbacks, Japanese Patent Publication No. 58231/1986 discloses a concept of storing a paint supply passage wound in a coil in a painting gun.

However, both of the above inventions and inventions lengthen the paint supply passage arranged in the coating gun to reduce the electric resistance of the metallic paint flowing in the paint supply passage of the coating gun during the coating work on the object to be coated. It is only intended to eliminate the above-mentioned inconvenience.

[Problems to be Solved by the Invention]

The need to prevent electric leakage and insulation breakdown of the coating gun is not only during painting work on the object to be coated, but also when the coating gun is in operation and the coating and air supply is temporarily stopped. Care must be taken even when the painting work is interrupted.

This is because even with the coating gun in the above-mentioned state, metallic paint remains in the paint passage, which may lead to electric leakage and cause the safety device to operate unnecessarily. There is also air remaining, which is released from compression and may cause dew condensation due to temperature changes, which may lead to leakage of electricity and unnecessarily activate the safety device.

The present invention is intended to eliminate the above-mentioned inconvenience.

[Means for Solving the Problems]

A paint spray hole with a needle-shaped electrode protruding from the high-voltage applying section for spraying paint to the tip of the paint, and a spray atomizing air spray hole and a pattern of spray paint near the spray hole A high-voltage supply unit that is provided with an air injection hole and conducts electricity to the paint charging high-voltage application unit, the paint charging high-voltage application unit, the paint atomization air injection hole, and an atomized paint pattern formation air injection hole In the air atomization type electrostatic coating gun with a paint supply path and an air supply path for supplying paint and air respectively, and a conductive member for grounding attached to the rear end, the main part of the gun body is made of an electrically insulating material. And a high voltage supply unit housing chamber inside the gun body, and a paint conduit on the outer periphery of the chamber.
An air conduit accommodating chamber is formed, and in the high voltage supply unit accommodating chamber,
In addition to accommodating the high-voltage supply part, the paint conduit and the air conduit accommodating chamber are provided with a paint conduit for winding the high-voltage supplying part accommodating chamber into a coil, and a paint conduit. It is configured to be housed by being surrounded by an air conduit.

〔Example〕

The coating gun body 1 includes, for example, a front member 1A, an intermediate member 1B, and a rear member 1 made of an acetal resin-based electric insulating material.
It is made of C and fits the three into one. The grounding conductive member 2 is attached to the rear bridge portion of the rear member 1C. On the rear end surface of the grounding conductive member 2, a high voltage cable insertion mechanism 2A, a paint atomization air hose insertion mechanism (not shown), a paint hose 2B insertion mechanism, and an atomized paint pattern formation air hose insertion mechanism 2C are arranged. However, each mechanism has a high voltage cable through hole 2D penetrating the grounding conductive member 2 and the rear member, a paint feed through hole 2E, a paint atomizing air feed through hole (not shown), and an atomized paint. Pattern forming air feed through hole 2
It is formed as each through hole of F. A cap 4 having a paint atomizing air injection hole 5 and a pattern forming air injection hole 6 for the atomized paint is screwed and fixed to the tip of the front member 1A with a screw ring 3. Similar to a normal coating gun, air is supplied to the paint atomizing air injection hole 5 in a portion formed by the front member 1A, the screw ring 3, and the cap 4 screwed to the front member 1A by the screw ring 3. An air passage 5A for sending, an air passage 6A for sending air to the pattern forming air injection hole 6 for the atomized paint, and a paint passage 7A for sending paint to the paint charging high voltage applying section 7 are formed. The tip of the paint charging high-voltage applying section 7 is formed as a beak-like beak as a paint injection hole, and this is seen in the paint atomization air injection hole 5 of the cap 4. Further, a needle-shaped electrode 8 is housed in the paint charging high-voltage applying section 7, which projects as a needle-shaped electrode 8 as a paint charging high-voltage applying member from the paint atomizing air injection hole 5 at the tip of the cap 4. There is. The needle electrode 8 is provided in the high voltage applying portion 7 for charging the paint.
The base is connected to an electrode guide 9 which is pressed against a high resistance tip of a high voltage rod 10 as a high voltage supply unit via a spring. In the structure of the high voltage rod 10, a high resistance 12 is arranged at the tip of a high voltage cable 11, and this is covered with a resin insulating material.

The high-voltage voltage rod 10 as the high-voltage supply path is provided with the front member 1A.
And a rear member 1C, the base of the high voltage supply passage accommodating chamber 13 formed in the coating gun main body 1 is a high voltage formed at a position where the rear member 1C of the coating gun main body 1 and the grounding conductive portion 2 match. It is housed and fixed in a state of penetrating through the through hole 2D that constitutes the cable insertion function 2A.

The paint passage 7 for feeding the paint under pressure to a paint charging high voltage applying portion formed on the front member 1A forming the paint gun body 1.
A, each air passage 5 for sending air under pressure to a paint atomizing air injection hole 5 provided in a cap that is attached to the front member with a screw ring, as well as to a pattern forming air injection hole 6 for atomized paint
A and 6A and a paint feeding through hole 2E formed in a rear member 1C integrally mounted with a grounding conductive portion 2 forming the painting gun body 1 as well as a paint atomizing air feeding through hole (not shown). ), A paint conduit 14 that forms a paint supply path and air conduits 15 and 16 that form each air supply path are coiled together between the atomized paint pattern forming air feed through holes 2F. A paint passage formed by inserting the body assembly 17 into the high-voltage supply unit accommodation chamber 13 and forming the tip of each conduit in the front member 1A.
14, each air passage 15, 16 and the rear end of each conduit to the rear member 1
Fit and fix in each feed through hole formed in C. Between the front member 1A and the rear member 1C, the intermediate member 1B for covering the high-voltage supply unit accommodating chamber 13 and the conduit assembly 17 inserted therethrough is arranged,
Join the front and rear members. Needle valves are arranged in the paint feed through hole, paint atomization air feed through hole, and atomized paint feed through hole, respectively, and the tip tapered portions are inserted into the paint and air feed through holes, respectively, and then painted. It is screwed onto the gun body 1 so that it can move back and forth.

Accordingly, by advancing and retracting the needle valve (not shown), the flow rate of the paint and the paint flowing through each air conduit and the air can be arbitrarily changed.

The operation will be described below.

A high-voltage static electricity generator, a high-pressure air supply device, and a paint supply device (all not shown) are operated.

As a result, the high-voltage static electricity is distributed through the high-voltage cable (not shown), the high-voltage rod 10 of the coating gun body 1 and the electrode guide to the high-voltage applying section 7 for charging the coating material, and The voltage is applied to the needle-shaped electrode 8 which is a high voltage applying member for charging the coating material and which projects from the tip of the coating material injection hole formed in the application high voltage applying portion 7. Further, the coating material passes through a hose (not shown) and enters the coating material charging high voltage applying portion 7 from the coating material feeding through hole 2E, the coating material conduit 14 and the coating material passage 7A. It is applied and ejected. Further, the air passes through a hose (not shown), each air feeding through hole, the air conduits 15, 16 and the air passage 5
It is sprayed from the paint atomizing air injection hole 5 and the pattern forming air injection hole 6 of the atomized paint through A and 6A. Then, the paint is atomized by the air ejected from the paint atomizing air injection hole 5, and when the paint passes through the corona discharge field generated between the needle electrode to which a high voltage is applied and the grounded object to be coated. It is electrically charged and sprayed and applied to an object to be coated (not shown). The air ejected from the atomized paint pattern forming air ejection holes 6 is used to set the atomized paint to a desired coating pattern.

The paint conduit is made of insulating material.

On the other hand, when in this coating state, the atomized paint is
The injection hole at the tip of the coating gun is charged by the high voltage applied to the needle electrode 8, but in the case of the solid paint that is often used in general industrial painting, the paint in the paint conduit has a high resistance value. There is no possibility that electrostatic painting cannot be performed by contacting the grounding conductive member with the automatic valve device (not shown) in the grounded state. Further, even in the case of a metallic paint having a property that a bridging phenomenon occurs due to the influence of a ground object approaching the paint conduit 14 and the conductive material for ground is conducted, and as a result, electrostatic coating cannot be performed. Since the paint conduit 14 is covered by the electrically insulating member, the bridging phenomenon is less likely to occur even if a ground object comes into contact with the paint conduit 14. Since the metal component is maintained in a uniformly dispersed state, the bridging phenomenon does not occur, and therefore, despite the fact that the automatic valve device is grounded,
Good and safe electrostatic coating can be performed.

In this embodiment, the valve device is described as being built-in, but it goes without saying that it may be provided in the vicinity of the coating gun. Conventionally, a long paint conduit, especially for metallic paint, was stretched outside, which required a vast installation space due to electrical restrictions on installation.However, that space was almost zero, and , Good electrostatic coating can be performed.

Further, when the automatic valve device is installed on the exterior, the middle of the wound paint conduit and the automatic valve device may be short-circuited to the ground with a joint or the like.

As described above, according to the air atomization type electrostatic coating gun of the present invention, since the long paint conduit is wound so as to be integrated with the coating gun and covered with the electrically insulating member, the installation space is reduced. It can be made extremely small and can be downsized, and good paint can be applied to any paint.

Further, although the long paint conduit is exposed and comes close to the grounded object, and there is a possibility of causing a spark to cause a fire, the paint conduit is entirely housed in the electrically insulating member according to the present invention. Therefore, there is an effect of preventing a fire from being caused by the spark.

The feature of the present invention is that the paint conduit 14 and the air conduits 15, 16 are
The conduit assembly 17 together with the above is wound in a coil shape so as to surround a high voltage supply accommodating chamber for accommodating a high voltage rod which is a high voltage supply section. It goes without saying that this may be a cart-rich type component.

With this configuration, even when the paint supply and the air supply are temporarily stopped while the coating gun is in the operating state, electrical leakage may occur through the paint (metallic paint) remaining in the paint supply passage, or air may leak. The air remaining in the supply path is released from pressure and expands, which causes dew condensation due to temperature change, which energizes the air supply dew condensation, or leaks electricity through this dew condensation to operate the safety device unnecessarily. The inconvenience was as described above.

Moreover, by constructing the paint supply passage and the air supply passage as in the present invention, the paint remaining in the paint conduit 14 wound in a coil settles down and the air A floats as shown in FIG. Also, the water droplets B and C that have condensed on the inside of the air conduits 15 and 16 wound in a coil shape settle down below the conduits as shown in FIG. Therefore, the upper portion of the paint conduit 14 and the air conduits 15 and 16 will be formed with an insulator due to the discontinuity of the air that has floated, which will cause a leakage of electricity through the residual paint (metallic paint).
It is possible to prevent electric leakage due to condensed water droplets.

[Effect]

The present invention has been developed in paint supply, air supply channels that have been previously unsolved by those skilled in the art by using paint and air conduits formed as described in the detailed description of the invention. It was possible to solve the inconvenience of leakage caused by water droplets.

Further, according to the present invention, since the coating gun main body is formed as the front member and the intermediate member rear member of the cylindrical body, the front member and the rear member can be easily processed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of the present invention. FIG. 2 is a partially cutaway view showing air levitation in a conduit assembly of a paint conduit and an air conduit, and a water droplet sedimentation state. 1A ... front member 1B ... intermediate member 1C ... rear member 2 ... grounding conductive member 2A ... high voltage cable insertion mechanism 2B ... paint hose insertion mechanism 2C ... atomized paint pattern formation air hose insertion mechanism 3 ... Screw ring 4 ... Cap 5 ... Paint atomization air injection hole 5A ... Paint atomization air passage 6 ... Atomization paint pattern formation air injection hole 6A ... Atomization paint pattern formation air passage 7 ... High voltage application section for paint charging 7A ... Paint passage 8 ... Needle electrode 9 ... Electrode guide 10 ... High voltage rod 11 ... High voltage cable 12 ... High resistance 2D ... High voltage cable penetration Hole 2E …… Paint feed through hole 2F ... atomized paint pattern shaping air infeed through-hole 13 ...... high voltage supply unit accommodating chamber 14 ...... paint conduit 15, 16 ...... air conduit 17 ...... conduit assembly

Claims (1)

[Claims] 1. A paint injection hole having a needle-shaped electrode projecting a paint charged from a paint charging high-voltage applying section at its tip, and a paint atomizing air injection hole and a fog near the paint injection hole. Of high-voltage paint for charging the paint, a high-voltage supply unit for conducting electricity to the high-voltage applying unit for charging the paint, a high-voltage applying unit for charging the paint, the paint-atomizing air injection hole, and the atomizing paint In an air atomization type electrostatic coating gun in which a paint supply passage and an air supply passage for supplying paint and air respectively to the pattern forming air injection holes are provided, and a conductive member for grounding is attached to the rear end, the main part of the gun body Is made of an electrically insulating material,
A high voltage supply section accommodating chamber is formed inside the gun body, and a paint conduit and an air conduit accommodating chamber are formed on the outer periphery of the chamber, and the high voltage supply section is accommodated in the high voltage supplying section accommodating chamber, and a paint conduit, In the air conduit chamber, the high-voltage supply unit accommodating chamber is surrounded by a paint conduit forming a paint supply passage wound in a coil shape, and an air conduit forming the air supply passage. Air atomizing electrostatic painting gun.