JP3398035B2 - Needleless two-liquid concentric nozzle spray gun - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Related to a coating device that applies two or more liquid materials such as multicolor paints and two-component adhesives, and particularly to the improvement of a needleless concentric nozzle spray gun in which two paint nozzles are concentrically arranged. .

[0002]

2. Description of the Related Art A method for spray coating a multi-liquid type liquid material is a method in which the liquid materials are mixed in a predetermined ratio in advance and then coated with a general one-component spray gun within a usable time. However, this method has a problem in that the waste of time that must be mixed in advance and the waste of the residual paint that occurs when the work is completed, as well as the work of having to completely wash the mixed paint. Further, as a mechanical device, there is a method in which a multi-component paint is divided into two components, mixed by a static mixer in a two component coating device, and supplied to the above general one-component spray gun for coating. However, there is a problem that the device becomes large and the initial cost becomes high, and there are problems in handling and maintenance.

Also, in the case of multicolored pattern coating, the heads of two or three spray guns are attached to one handle part, and different paints are sprayed from the respective guns so that the spray angles intersect and mix. Although the method of applying with a double-headed gun or a multi-headed gun is used, the cross-mixing of the spray flow is not sufficiently mixed and cannot be used for a two-component curing type paint. Also, the painting of multicolored patterns makes the gun heavy, which makes it difficult to handle.

Two types of large and small paint nozzles are concentrically arranged,
Supply two-component paint or two-component adhesive main agent / hardener or two different liquid materials with different paint colors to each paint nozzle, and eject two liquid materials discharged from the paint nozzle to the tip of the paint nozzle. The concentric nozzle spray gun, which mixes and atomizes with compressed air from the attached air cap and applies it to the surface of the object to be coated, is a spray coating machine developed in place of the other coating method described above, which was filed by the applicant. Japanese Patent Laid-Open No. 5-210
No. 129 and JP-A-6-99188.

In the above-mentioned known concentric nozzle spray gun, the discharge of the first paint nozzle is opened and closed on the outer circumference of the second paint nozzle. That is, the second paint nozzle is also used as the needle valve for opening and closing the discharge of the first paint nozzle, and the second paint nozzle is also provided with a separate needle valve. This causes the second paint nozzle and the needle valve for the second paint nozzle to slide. In this structure, the tip sheet portion of the second paint nozzle that also serves as the needle valve and the valve seat of the first paint nozzle often become incomplete due to sticking of paint, etc., and the reliability of the valve seat is impaired. There's a problem.

Further, since the needle valve of the second paint nozzle is pulled and opened after the second paint nozzle is pulled and opened, the pulling margin of the needle valve becomes longer and the total length of the spray gun becomes longer. At the same time, due to the combination of two slides, the assembly complexity due to processing tolerances, etc., and the relatively complex structure,
Two-component paints, which have a large number of parts and are susceptible to sticking of paints, are difficult to obtain long-term stability, and also have problems in maintenance.

[0007]

In the concentric nozzle spray gun described above, there is a problem that the sheet property reliability of the sheet portion of the second paint nozzle that opens and closes the first paint nozzle is insufficient. , A new mechanism for solving this is because the mechanism has two sliding mechanisms of the second paint nozzle and the needle valve for the second paint nozzle, and the mechanism is not easy to maintain. Is to provide.

[0008] The problem is to simplify and miniaturize the mechanism of the concentric nozzle spray gun including the paint flow path as much as possible, without deteriorating the mixing and atomizing function of the concentric nozzle spray gun which is an advantage of the conventional product. It is to improve the maintainability and handleability by maintaining the performance and simplifying the mechanism. Further, the first and second paint nozzles are subjected to a surface treatment to further improve the cleaning property of the concentric nozzle spray gun.

[0009]

A two-liquid concentric nozzle spray gun of the present invention made to solve the above-mentioned problems has a first paint nozzle screwed to an air spray gun body, A second paint nozzle is concentrically arranged in the paint flow path, and an air cap is attached to the outer circumference of the first paint nozzle to atomize liquid materials such as two kinds of paint discharged from the concentric nozzle with compressed air. In the concentric nozzle spray gun, insert the second paint nozzle, which is installed in the paint passage of the first paint nozzle that is screwed into the spray gun body, from the rear of the first paint nozzle and fix it directly to the spray gun body. To do. Then, one liquid material is supplied between the first paint nozzle and the second paint nozzle from the first paint passage formed in the spray gun main body, and the liquid is further formed in the spray gun main body. Is a two-liquid concentric nozzle spray gun in which another liquid material is supplied from the second paint channel to the second paint nozzle. Further, the first paint nozzle and the second paint nozzle are always open, and the second paint nozzle is a two-component concentric nozzle spray gun in which the second paint nozzle is directly and detachably attached to the spray gun body.

Further, according to the present invention, the liquid material is supplied to each of the paint systems for supplying the liquid material to the first and second paint passages.
A liquid material shutoff device for stopping the supply and a three-way valve that is a liquid material switching valve for switching between the liquid material and the cleaning liquid are connected.
The three-way valve is set so that the liquid material is supplied to the two-liquid concentric nozzle spray gun, and the liquid material is supplied through the respective shutoff devices, and compressed air is supplied to the spray gun body to spray two kinds of liquid materials. Turn into. After the spraying operation, the cleaning liquid is supplied to the two-liquid concentric nozzle spray gun after the spraying operation, and when the cleaning liquid is supplied through the respective shutoff devices, the liquid material remaining in the paint flow path downstream of the three-way valve and the paint nozzle is A two-liquid concentric nozzle spray gun equipped with a cleaning supply device capable of discharging with a cleaning liquid, and a control device for controlling the operation thereof.

Further, the present invention is directed to a concentric nozzle spray gun in which a first paint nozzle is screwed into an air spray gun body and a second paint nozzle is concentrically arranged in a flow path of the first paint nozzle. This is a two-liquid concentric nozzle spray gun that has been surface-treated to form a resin film with excellent releasability on the liquid material contact part of the first and second paint nozzles.

As described above, the two paint nozzles arranged concentrically are fixedly attached to each other, so that the sliding portion unlike the needle valve mechanism is eliminated and the sliding packing is not provided. No paint leaks or sliding problems at the spray gun. A shutoff device and a three-way valve are provided in the paint flow passage of the spray gun or in the paint flow passage connected to the spray gun to operate the liquid material discharge opening / closing by air pressure or the like according to a command remotely controlled from the control device. .

The remote-controlled three-way valve discharges a small amount of residual liquid material in the downstream of the three-way valve and in the first and second paint nozzles with the cleaning liquid from the cleaning liquid supply device connected to the three-way valve when the spraying operation is stopped. By doing so, the problem of curing or paint sticking in the concentric nozzle is solved.

The first and second paint nozzles are surface-treated nozzles which are mainly coated with a Teflon resin having a good mold releasability, so that the nozzles can be washed with a small amount of cleaning liquid. The inside is thoroughly washed. In addition, even when disassembling and cleaning at the end of work, the second paint nozzle that is screwed and fixed can be pulled out from the rear part of the spray gun body without removing and attaching other parts of the spray gun body. The inside can be easily washed.

According to the present invention, the mechanism / structure is simplified and maintenance is facilitated while maintaining the conventional mixing / atomization function of the concentric nozzle spray gun. This ensures long-term performance stability of the concentric nozzle spray gun.

[0016]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a two-liquid concentric nozzle spray gun according to the present invention. 2 is a rear view of FIG.
The arrangement of paint joint and air joint is shown. FIG. 3 is a schematic diagram showing the configuration of the present invention. In the drawings, the same components are designated by the same reference numerals for the description.

In FIG. 1, a first paint nozzle 2 is attached to a spray gun main body 1 in a tapered and airtight manner and screwed to the spray gun main body 1. The second paint nozzle 3 is disposed in the center of the paint flow path 2a of the first paint nozzle 2 at a position retracted by several mm from the tip of the first paint nozzle, It is fixed to the spray gun body 1 while maintaining an appropriate flow path between it and the paint nozzle 3. In the second paint nozzle 3, the nozzle unit 3a is the nozzle mounting pipe 4
The nozzle mounting pipe 4 is screwed to the fixed joint 5
It is screwed and integrated into one. Two fixed O-rings 6 for hermetically partitioning the liquid material flow path to be supplied to the second paint nozzle 3 are fitted into the fixed joint 5. A supply port 7 for supplying the second paint nozzle 3 is formed between the two fixed O-rings 6. The second paint nozzle 3 has a nozzle unit 3a, a nozzle mounting pipe 4, and a fixed joint 5 screwed together to be fixed by screwing from the rear portion of the spray gun body 1. Then, the liquid A is supplied to the first paint nozzle 2 from the paint passage 12, and the liquid B is supplied to the second paint nozzle 3 from the paint passage 11. The B liquid discharged from the second paint nozzle 3 is discharged from the first paint nozzle 2 while being mixed with the A liquid at the outlet of the first paint nozzle.

An air cap 8 is airtightly joined to the outer periphery of the first paint nozzle 2 by a cap cover 15 and attached to the spray gun body 1. Compressed air is jetted from the central air hole 10 of the air cap 8 and the ring-shaped gap formed on the outer periphery of the first paint nozzle, and A from the first paint nozzle is injected.
-Promoting mixing and atomization of the mixed flow of the liquid B. Then, an air flow from the side air holes 9 of the air cap 8 is converted into a spray flow that is sprayed in a conical shape, and the spray flow that converts the conical spray flow into a flat spray flow and forms an elliptical pattern. To do. The air flow from the side air holes 9 is mainly intended for workability in spray coating, but in the case of a two-component spray, it also contributes to promotion of mixing of the two liquids. The air flow supplied to the air cap 8 is divided into the central air hole 10 and the side air hole 9 so that the flow path is divided.
From the air joint 14a to the central air hole 10 via the air flow path 14, and from the air joint 13a to the main body air flow path 13
And is supplied to the side air holes 9. Reference numeral 16 denotes a hook for supporting the spray gun main body 1, into which a supporting rod of a device for driving the spray gun is inserted and fixed by a set screw 17.

In the rear view of FIG. 2, the paint joint 1
Reference numeral 2a is for supplying the liquid A of liquid material to the first paint nozzle 2, and paint joint 11a is for supplying the liquid B of liquid material to the second paint nozzle 3. Further, the air joint 14a supplies atomized air to the central air hole 10 of the air cap 8, and the air joint 13a supplies pattern air to the side air hole 9. And
The fixed joint 5 at the rear of the spray gun body 1 can be loosened by a screwdriver or the like even when it is set in the spray gun moving device, and the second paint nozzle 3 integrated as shown in FIG. It is designed to be easily pulled out without attaching or detaching other parts.

In the schematic diagram of FIG. 3, the liquid material A
A storage tank 20 for storing the liquid is connected by a pump 19 to a paint joint 12a for supplying to the first paint nozzle 2 via a three-way valve 18 for the A liquid and a two-way valve 18a. On the other hand, from the storage tank 23 that stores the liquid B of the liquid material to the pump 22
By means of the three-way valve 21 for liquid B and the two-way valve 21a, the paint joint 11 for supplying to the second paint nozzle 3
connected to a. ON / OFF of spray is three-way valve 18
・ 21 is the state which connects A liquid and B liquid to the spray gun,
By the time control set by the controller or an external command,
This is performed by turning on / off the two-way valves 18a and 21a.

The cleaning of the nozzle portion is performed after the spraying is stopped, and is branched from the storage tank 26 in which the cleaning liquid is stored by the pump 25 through the two-way valve, and the three-way valve 18 for the liquid A and the liquid B.
・ Supplied to 21. The three-way valves 18 and 21 are switched to a state in which the cleaning liquid is connected to the spray gun, the two-way valve 24 for supplying the cleaning liquid is opened, and the two-way valves 18a and 21a are turned ON / OFF, respectively. Cleaning is performed. Further, when the downstream flow passage is washed every time the spray is stopped, the two-way valve 24 is always open, so the two-way valve 24 may be omitted.

Control of the valves is performed by supplying control air to each valve in response to a control command from a control device connected to an air source (not shown) and operating the valve by air pressure. Also,
From the control device connected to the air source, the atomization air passing through the central air hole 10 supplied to the air cap 8 and the pattern air passing through the side air hole 9 are pressure-controlled to be ON / ON.
It is supplied after being turned off. In the configuration of FIG. 3, the A liquid, the B liquid, and the cleaning liquid are adjusted to a predetermined discharge amount by the pump rotation speed or the pumping pressure, and are supplied while being controlled to a predetermined discharge amount.

Further, in order to confirm the discharge amounts of the A liquid and the B liquid, by controlling the operation of each three-way valve and each two-way valve, only the A liquid is discharged or only the B liquid is discharged to change the flow rate. It is also possible to confirm the measurement. In addition, the embodiment of FIG.
The liquid material cutoff device and the three-way valve are installed outside the two-liquid concentric nozzle spray gun and connected to the paint joints 11a and 12a, but the arrangement positions of the liquid material cutoff device and the three-way valve are limited to the outside. Instead, it can be installed in the spray gun body, and the effect is the same.

In the cross-sectional view of FIG. 1, the first and second paint nozzles, which have been subjected to a surface treatment mainly composed of Teflon resin having a good releasability, have very good cleaning properties and are compatible with each other. It is composed of parts, and has a structure in which the paint nozzle diameter can be easily selected and replaced depending on the type and viscosity of the liquid material used and the mixing ratio of both the A and B liquids.

[0025]

Since the present invention is constructed as described above, it has the following effects.

The second paint nozzle is concentrically arranged in the paint flow path of the first paint nozzle, the second paint nozzle is fixed to the spray gun body, and a structure without a needle valve is provided. A reliable and stable concentric nozzle spray gun with no moving parts and no paint leakage from the seat and packing can be obtained.

By simplifying the component structure, the number of assembling steps can be reduced, highly accurate performance quality with no variations can be obtained, and the cost can be reduced.

Further, by removing the needle valve that is paired with the paint nozzle, the first and
The diameter of the second paint nozzle can be selected by replacing only the paint nozzle, which facilitates adaptation to various liquid materials.

By subjecting the first and second paint nozzles to a surface treatment having a good releasability, the cleaning property is further improved.

The ON / OFF control of the liquid material is performed by a liquid material shut-off device / three-way valve or color changer valve arranged outside the spray gun, so that it is easy to select and employ a valve mechanism according to the property of the liquid material. Becomes

Since the paint passage of the spray gun body is constituted by an open passage without a valve, the paint passage can be easily washed by disposing a washing liquid supply device and feeding the washing liquid when the spray is stopped. , Especially in the case of spraying two-component curing type paint, curing in the spray gun,
It is a highly reliable two-component spray device that does not cause sticking.

At the time of cleaning after the work is completed, the concentric nozzle spray gun can be disassembled and cleaned in the paint passage and the second paint nozzle with the concentric nozzle spray gun still attached to the apparatus, and the concentric nozzle spray gun is excellent in maintainability. Becomes

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a two-liquid concentric nozzle spray gun of the present invention.

FIG. 2 is a rear view of FIG. 1 in which each joint is arranged.

FIG. 3 is a schematic diagram showing a configuration of the present invention.

[Explanation of symbols]

1 spray gun body 2 First paint nozzle 3 Second paint nozzle 5 fixed joint 6 Fixed O-ring 8 air caps 9 Side air holes 10 Central air hole 11, 12 Paint channel (inside spray gun) 11a, 12a paint joint 13, 14 Air flow path 13a, 14a Air joint 18, 21 Three-way valve (A, B) 19, 22, 25 pumps 22, 23 Storage tank 26 Cleaning liquid storage tank

Claims (6)

(57) [Claims] 1. A first paint nozzle is screwed to an air spray gun body, a second paint nozzle is concentrically arranged in a paint flow path of the first paint nozzle, and the second paint nozzle is concentrically provided on the outer circumference of the first paint nozzle. In a concentric nozzle spray gun that attaches an air cap and atomizes liquid materials such as two kinds of paint discharged from the concentric nozzle with compressed air, in the paint channel of the first paint nozzle screwed to the spray gun body The second paint nozzle to be installed,
Insert it from the rear of the first paint nozzle, fix it directly to the spray gun body, and insert one side between the first paint nozzle and the second paint nozzle from the first paint passage that is drilled in the spray gun body. A two-liquid concentric nozzle spray gun configured to supply a liquid material and further supply another liquid material to a second paint nozzle from a second paint passage formed in the spray gun body. 2. The first paint nozzle and the second paint nozzle are
The two-liquid concentric nozzle spray gun according to claim 1, which is always open. 3. The two-component concentric nozzle spray gun according to claim 1, wherein the second paint nozzle is arranged so as to be directly attachable to and detachable from the spray gun body without attaching and detaching other parts of the spray gun body. 4. A liquid material interrupting device for supplying or stopping the supply of the liquid material is connected to each of the flow path systems for supplying the liquid material to the first paint flow path and the second paint flow path.
-The two-liquid concentric nozzle spray gun described in 2. 5. A liquid material blocking device for supplying or stopping the supply of the liquid material to each of the flow path systems for supplying the liquid material to the first paint flow path and the second paint flow path, and for feeding the cleaning liquid. The liquid material switching valve that switches the flow path is connected, and after the liquid material supply is stopped, the liquid material remaining in the paint flow path and the paint nozzle downstream of the liquid material switching valve is discharged as a cleaning liquid via the liquid material switching valve, respectively. The two-liquid concentric nozzle spray gun according to claim 1 or 2, further comprising a cleaning supply device capable of controlling the operation and a control device for controlling the operation thereof. 6. A first paint of a concentric nozzle spray gun in which a first paint nozzle is screwed to an air spray gun body, and a second paint nozzle is concentrically arranged in a flow path of the first paint nozzle. The two-component concentric nozzle spray gun according to claim 1 or 2, wherein the nozzle and the liquid material contact portion of the second paint nozzle are subjected to a surface treatment for forming a resin film having a good mold release property.