JPS62191057A - Electrostatic painting gun - Google Patents

Abstract

PURPOSE:To perform uniform painting by eliminating the spattering of a coating agent, by mounting a nozzle having the air gap communicated with the center bore of a hollow shaft to the circumference of a front cylindrical part and providing a guide hole to the peripheral edge of a partition wall so as to pierce therethrough before and behind. CONSTITUTION:A needle valve 42 is retracted by pulling a trigger 13 to open a coating agent opening and closing valve 30 and the coating agent flowing through a coating agent flow passage 16 flows out to the partition wall 26 of a nozzle 11 and the inner surface of the cylindrical part 27 of a hole part through an L-shaped jet pipe 28. the coating agent flows forwardly along the inner surface of the cylindrical part 27 with the rotation of the nozzle 11 to flow out to the taper inner surface of a cylindrical part 9 through a guide hole 29. The coating agent flows to the front end of the nozzle 11 along the inner surface 9A while develops in a membrane form by the high speed rotation of the nozzle 11 and atomized by the sharply formed leading end of the nozzle, electrostatic force due to high voltage applied to th front end of the nozzle and the atomizing force of the rotary air stream injected from the circumference of the cylindrical part 9 to be emitted in the form of fine particles.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a static 1! that can improve the adhesion efficiency of paint and improve the quality of coating. Regarding paint guns.

[Conventional technology]

2. Description of the Related Art So-called IS electrocoating, which can increase the adhesion efficiency of a coating material by electrostatic force by creating a potential difference between a dispensing tool for spraying a coating material and an object to be coated, is increasingly being used.

[Problem that the invention seeks to solve]

However, with conventional coatings, the coating material tends to scatter in a clump-like manner, making it difficult to obtain a uniform coating film.

In the present invention, a nozzle having a cylindrical part at the front and rear is attached to a hollow shaft that is pivotally supported at the tip of the gun body, and by using a trigger, air and paint are sprayed individually, and the hollow shaft can be rotated on its own axis by a turbine blade. Based on this, the aim is to improve coating quality, solve the above problems, and provide an easy-to-handle electrostatic painting gun. [Means for solving the problems] Hereinafter, the above-mentioned An embodiment of the means of the present invention that can achieve the above objectives and solve the problems will be described based on the drawings.

In the figure, the electrostatic painting gun 1 has an insulating part 5 formed on the body 3 of the gun body 2, and a hollow shaft 6 pivoted at the tip of the body 3, which has a cylindrical shape at the front and back. A nozzle 11 having an air gap 1o is installed around the part 9, and a first air flow path 15 and a paint flow path 16, which are opened and closed by operating a trigger 13, and a second air flow path 17 for rotating the hollow shaft. , a power supply cord 19 that supplies high voltage between the nozzle 11 and the object to be coated is visible.

The gun body 2 is shaped like a pistol, with a barrel 3 screwed onto the right-angled upper surface of the handle 31, and the barrel 3 consists of a middle frame 32 and a front frame 33 at its tip.

The handle portion 31 is made of a metal material such as Guicast, and the middle frame 32 and front frame 33 are made of industrial synthetic resin. In addition, the middle frame 32 has a handle portion 31.
The trigger 13 is attached to hang down at the front.

The handle part 31 also has a stepped shape extending horizontally above the air opening/closing valve 21 which extends from the nipple 36 at the lower end of the handle part 31 and is opened and closed using the valve shaft 37 which retreats when the trigger 13 is pulled. A flow path 41 communicating with the hole 40 is provided.

Further, the trigger 13 can move the needle valve 42 backward by its operation.
Further, the needle valve 42 passes through a receiving box 43 screwed into the handle portion 31 and is biased forward by a spring, and the displacement is adjusted by an adjustment screw 44 at the rear end of the receiving box 43.

The middle frame 32 is screwed into the upper surface of the handle portion 31, and the front surface is screwed with a cylindrical set screw 49 having a head that engages with the stepped portion of the hole portion 40. conclude. The rear end of the inner hole of the set screw 49 has a hexagonal shape, and the opening amount of the inner hole is adjusted by moving the valve shaft 50 of the air volume adjustment screw 52, which is screwed into the rear end of the hole 40, into contact with and separating from the valve shaft 50. can be adjusted.

In the middle frame 32, a guide hole 53 communicating with the hole 40 and a guide hole 55 whose rear end opens at a side hole 54 in front of the trigger 13 are formed above and below, and below the guide hole 53, the needle is connected. A through hole 56 into which the valve 42 is loosely inserted is provided.

The front frame 33 is a rectangular parallelepiped block, and is bolted to the front surface of the middle frame 32 using flanges of the middle frame 32. Further, the front frame 33 has the guide hole 5 in its upper part.
a turbine chamber 60 concentric with 3 and closed by a front lid 59;
Further, the turbine chamber 60 is provided with a bearing hole in which a bearing 61 is attached through the small diameter portion. Note that the bearing 61 is
By being attached across the middle frame 32 and front frame 33, the middle frame 32 and front frame 33 can be held concentrically.

The part 159 is made of a conductive material and is screwed onto the front frame 33 at the front part of the turbine chamber 60, and holds a bearing 62 concentrically with the guide hole 53. A hollow shaft 6 is horizontally supported.

A front cover 64 is screwed to the front end of the front end 1i59 via a receiving plate that holds a bearing 62, and the rear end of the hollow shaft 6 is opened in the guide hole 53, so that it is connected to the flow path 41. The hole 53 is the first air flow path 15 communicating with the hollow shaft 6.
is formed.

In addition, a stopper for supporting the rear end of the bearing 61 is attached to the rear end of the hollow shaft 6, and the nozzle 11 is attached to the front end.
A turbine blade 25 to be housed in the turbine chamber 60 is fixed to the hollow shaft 6. The turbine blade 25 is composed of a blade body of a well-known construction that is rotated by an air flow blowing in the tangential direction, and the turbine chamber 60 communicates with the front end of the guide hole 55 through an oblique hole L7.

The nozzle 11 includes a nozzle base 65 and a nozzle base 6.
5, and a nut that is screwed onto the rear part of the nozzle base 65 and presses and fixes the guide cylinder G6 against the step 67. The nozzle base 65 also has a partition wall 26 extending from a boss that is screwed into an external thread at the front end of the hollow shaft 6 and closes the front end.
A cylindrical portion 9.27 is provided at the front and rear of the cylindrical portion 9.27.
The inner surface 9A is formed into a cone shape whose diameter increases toward the front end and has a sharp point where it intersects with the outer surface 9B. Also bulkhead 2
6 is provided with small holes 69 radially provided at an angular pitch of, for example, 30 degrees, which open at the inner end of the hole in the boss and thus communicate with the center hole 23 of the hollow shaft 6. 9
On the other hand, the guide tube 66 has a large-diameter hole extending from the rear of the small hole 69 to the tip, thereby creating an annular air gap 1 formed of a narrow gap around the cylindrical portion 9.
0 is formed. Note that the front end of the guide tube 66 is discontinued at a position slightly rearward from the tip of the cylindrical portion 9.

Further, in the front frame 33, a paint opening/closing valve 30 is screwed into the lower center hole 71 and has a tapered hole at the inner end and a valve seat on which the needle valve 42 approaches and separates. Ru. In addition, the nozzle 1 is attached to the joint pipe fixed to the front end of the paint on-off valve 30.
An L-shaped discharge pipe 28 that opens on the inner surface of the cylindrical portion 27 is connected.

Note that the needle valve 42 is provided with an insulating portion 57 at its center.

Further, a small hole 76 facing diagonally downward is connected to the rear of the hole 71, and the small hole 76 is connected to a fitting fitting for the tip of a hose 73 which passes through a mounting fitting 72 which is attached to the lower end of the handle part 31 via a leg piece 79. 7
4 is electrically connected to the hole 75 into which it is screwed. Furthermore, Bose 73
is connected at one end to the paint pumping device, and the mounting fitting 72 is a tightening fitting 7 that reduces the inner diameter by screwing.
It is held at 7. In addition, the acid hose 73 has the coupling fittings 74,
A medicine passage 16 is formed through the hole 75, small hole 76, hole 71, and discharge pipe 28, and the cough medicine passage 16 is opened and closed by the medicine opening/closing valve 30 to which the needle valve 42 approaches and separates. .

Further, a hole 91 is provided in the lower part of the front frame 33, through which the second air flow path 17 can be formed and which communicates with the power supply cord 19.

The hole 91 has a small diameter hole 92 at its tip that communicates with the screw hole 58 into which the front cover 59 is screwed, and an internal thread into which the fitting 93 is screwed at its lower end. In 91,
Air holes 96 communicating with the inner surface of the turbine chamber 60 are provided in series.

The coupling fitting 93 fixes one end of an outer tube 100 made of an insulator, and the other end of the outer tube 100 is held by a presser fitting 99 that is screwed into the front surface of the hole 97 of the mounting fitting 72. or,
A power supply cord 19 passes through the hole 97, and the power supply cord 19 covers the core wire 101 with an inner wire edge 102, and also covers the outer wire edge 104 with a net-like ground wire 103 interposed therebetween. Note that the power supply cord 19 has an external wire edge 104 cut out, and the vicinity of the notched end is fixed with a presser foot p105 that is screwed into the hole 97 on the back side of the mounting bracket 72. In addition, the ground wire 103 protruding from the end is connected to the inner wire edge 1.
02 is brought into contact with a conductive ring 106 that is extrapolated. Further, the ring 106 is fixed using a stopper 107, and the screw 107 is electrically connected to a bolt 110 that identifies the mounting fitting 72 to the leg piece 79 via a spring 109. Therefore, the handle portion 31 has the leg pieces 79. Porto 11
0, the conductor AL is grounded to the ground wire 103 via the spring 109, screw 107, and lug 106.

The inner wire edge 102 of the power supply cord 19 has a gap with the outer tube 100 and extends to the lower end of the coupling fitting 93, and its core wire 101 has a gap with the outer tube 100, and its core wire 101 is connected to the resistor 112 and the spring accommodated in the small diameter hole 92. The spring 113 is connected to the front cover 59 via the spring 113.

Therefore, the high voltage of the power supply cord 19 is applied to the front M59, and the part 'fi59 is electrically connected to the hollow shaft 6 via the bearing 62, thereby connecting the nozzle 11 and the object to be coated (not shown). A high voltage is applied between the two.

Moreover, the gap between the outer cylinder 100 and the power supply cord 19 is
A part of the second air flow path 17 is formed.

The second air flow path 17 has its upper end connected to the air gap between the inner hole and hole portion 91 of the fitting 93 and the resistor 112.
It communicates with the turbine chamber 60 through the air hole 96 . The second air flow path 17 includes a through hole 11 extending outward from the center of the hole 97 of the mounting bracket 72, as shown in FIG.
5 to a fitting 117 for connecting a hose (not shown) leading to a high pressure air source. Note that the guide hole 115 has
An air control valve 119 having a valve shaft that adjusts the amount of air passing through by fitting close to a small hole at the inner end of the fitting 117, and an on-off valve 120 that shuts off and opens the through hole 115 are interposed.

Note that the on-off valve 120 is connected to the through hole 1 as shown in FIG.
A head 123.1 is provided with a pin body 122 that slides through a horizontal hole 121 that crosses the bottle body 15, and is screwed to both ends of the bottle body 122.
23, the bottle body 122
By aligning the circumferential groove 124 provided in the through hole 115 with the through hole 115, the through hole 115 can be opened and closed by positional deviation.

A cylindrical cap 125 that surrounds the nozzle 11 except for the front end is removably fitted to the front lid 59.

(Function) The nipple 36 and the fitting 117 are connected to a high-pressure air source, the hose 73 is connected to a paint pumping device, and the power supply cord 19 is connected to a predetermined voltage source.

Also, while opening the on-off valve 120, the air amount adjusting valve 1
By connecting 19 to 1I51, the high pressure air flowing through the second air flow path 17 passes through the air hole 96 and enters the turbine chamber 6.
The hollow shaft 6 and therefore the nozzle 11 are rotated at high speed by discharging to zero and blowing it onto the turbine blades 25.

Note that the air blown to the turbine M25 passes through the guide hole 55 of the middle frame 32 and is discharged from the side hole 54. Further, the power supply cord 19 charges the nozzle 11 at high voltage through the resistor 112, the spring 113, the front cover 59, the bearing 62, and the hollow shaft 6.

Further, by operating the trigger 13, the high pressure air passing through the first air flow path 15 flows into the center hole 23 from the rear end of the hollow shaft 6 via the air volume adjustment screw 52 and the guide hole 53. Air passes through the small hole 69 and is discharged in a cylindrical shape from the air gap 10 around the cylindrical portion 9. Furthermore, as the nozzle 11 rotates at high speed, the cylindrical airflow surrounding the cylindrical portion 9 spirals.

The high voltage of the power supply cord 19 is applied to the tip of the nozzle 11 as described above.

Further, by pulling the trigger 13, the needle valve 42 is moved back, the paint opening/closing valve 30 is opened, and the paint flowing through the paint flow path 16 is controlled as described above (through the L-shaped discharge pipe 28). , nozzle 1
It flows out to the inner surface of the cylindrical part 27 of the hole part of the partition wall 26 of 1. Further, as the nozzle 11 rotates, the paint flows forward on the inner surface of the cylindrical portion 27 and flows out through the guide hole 29 to the tapered inner surface 9A of the cylindrical portion 9.

On the inner surface 9A, the coating material flows to the front end while being developed into a thin film by the high-speed rotation of the nozzle 11, and the tip is formed sharply, so that the electrostatic force due to the high voltage applied to the front end Due to the atomizing force of the rotating airflow ejected from the periphery of the portion 9, the air is atomized and discharged in the form of fine particles. Further, the atomized coating material is discharged in a cylindrical shape within the spiral air flow at an initial velocity. Further, atomization is further promoted and uniformed within the swirling air flow, and the coating material is applied to the object while being sealed within the air flow. Furthermore, the Coulomb force acting on the paint particles allows the paint to be uniformly applied to the object to be coated.

〔Effect of the invention〕

In this way, the static 1 of the present invention! The painting gun has a gun body that is pistol-shaped so that it can be easily held using its handle, and a nozzle that has a cylindrical part with an air gap around the hollow shaft that is pivoted at the tip of the body. a first air flow path that opens and closes when a trigger is operated to supply air to the air gap; a paint flow path that includes a discharge pipe that extends to the nozzle when the trigger is operated; and a hollow shaft. a second air flow path for blowing air to the turbine blade attached to the turbine blade;
Further, a power supply cord for igniting a high voltage is attached to the nozzle, so that the nozzle, which rotates together with the turbine blade, can form a thin film of paint on the inner surface of the cylindrical portion. Furthermore, the thin film-like paint can be easily atomized by the spiral air flow flowing out from the air gap around the cylindrical part and the high-voltage electrostatic force applied to the nozzle, and the spiral air flow can be easily atomized. While being contained in the particles and being discharged at an initial velocity, the particles become finer and can be applied uniformly to objects having the opposite potential. In addition, by being confined by electrostatic force and a spiral air flow, efficient coating is possible without scattering of the coating material, and a coating film can be formed evenly, resulting in many effects such as improving coating quality.

In the static i-painting gun of the present invention, as schematically shown in FIG. 9, an air nozzle 130 having an injection part 127 extending into the center hole 23 is installed at the tip of the middle frame 32 to improve air blowing efficiency. It can be modified in various ways, such as by increasing the voltage (or by applying a high voltage through an electrode made of carbon or the like that contacts a slip ring (shown in the figure) provided on the hollow shaft).

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the present invention, Fig. 2 is a right side view thereof, Fig. 3 is a schematic sectional view of the center thereof, Fig. 4 is a sectional view showing the paint flow path, and Fig. 5 is a sectional view illustrating the second air flow path and the power supply cord, FIG. 6 is a sectional view taken along the line A-A in FIG. FIG. 8 is a sectional view schematically showing the on-off valve of the mounting fitting, and FIG. 9 is a partially enlarged sectional view showing another example of the first air flow path. 2--Gun body, 3--Body part, 5--Insulating part, 6--Hollow shaft, 9--Cylindrical part, 10--
Air gap, 11--Nozzle, 13--Trigger, 15--First air flow path, 16--Paint flow path,
17... Second air flow path, 19... Power supply cord,
21-air on/off valve, 23-center hole, 25--turbine blade, 26--partition wall, 27-cylindrical part, 28-discharge pipe, 29--conductor hole, 30--paint on-off valve. Patent applicant Meiji Machinery Co., Ltd. Agent
Patent Attorney Tadashi Naemura Figure 8 w9 Figure

Claims (1)

[Claims] (1) An insulating part is formed in the body of a pistol-shaped gun body having a handle, and a hollow shaft is pivotally supported at the tip of the body, and the hollow shaft is provided with a cylindrical part at the front and rear of the partition wall, and a cylindrical part at the front. A nozzle having an air gap communicating with the center hole of the hollow shaft is installed around the periphery, and a conduit hole is provided on the periphery of the partition wall to communicate back and forth, and an air opening/closing valve is provided which is opened and closed by operating a trigger supported by the gun body. A first air flow path that feeds air into the center hole of the hollow shaft, and a paint opening/closing valve that is opened and closed by a needle valve that moves forward and backward in response to the operation of the trigger, and is located in a cylindrical portion behind the partition wall of the nozzle. A paint flow path leading to an opening discharge pipe and a second air flow path for blowing air to a turbine blade attached to the hollow shaft are provided, and a high voltage is further supplied between the nozzle and the object to be coated. An electrostatic painting gun equipped with a power supply cord.