JPH09193977A - Pressurized air feeding mechanism for pressurized container of low pressure spray gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press-feeding mechanism which can feed a paint by quickly responding to a trigger control of a spray gun, and a pressurized air feeding mechanism of which the check valve is not corroded with an organic solvent such as a paint, and of which the mechanism is simple and of which the handling property is easy, for a pressurized container which is attached to a internally mixing type spray gun. SOLUTION: On the container lid 20 of a pressurized container, a pressurized air joint set 1 for which a check valve 3 and an air purging valve 4 are jointly provided and integrated, is installed, and the check valve 3 has a thin film-form valve plate with a warping elasticity, being operated by low pressure air. Then, by turning the check valve 3 main body of the pressurized air joint set 1 being integrated, the opening/closing of the air purging valve 4 is performed for the pressurized air feeding mechanism.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a spray pressure of 100 kPa.
In a low-pressure spray gun for atomizing and spraying paint with the following low-pressure air, it relates to a paint container that is directly attached to the low-pressure spray gun. The present invention relates to a pressurized air supply mechanism when supplying compressed air.

[0002]

2. Description of the Related Art A paint container having a capacity of about 1 liter is directly attached to a paint joint of a hand type air spray gun, the paint is supplied to the spray gun, and atomized at the tip of the spray gun for spray painting. In the coating method, in recent years, in order to reduce the scattering of fog due to the diffusion of compressed air and improve the coating efficiency, the spraying air pressure is set to 10
Low-pressure spray guns, which perform spray coating with low-pressure air of 0 kPa or less, have become widely used worldwide.

This low-pressure air spray gun is classified into an external mixing type that uses a large amount of low pressure air and an internal mixing type that uses a relatively low amount of air. In the case of the external mixing type, there are various tip structures, but when applying back pressure, the wicking type paint supply system utilizing the vacuum force generated at the tip of the spray gun cannot be used. A gravity type that utilizes the weight of the paint itself, or a pressure feeding type that uses a pressurized container or the like is used. On the other hand, in the internal mixing method, pressure is applied to the tip of the paint nozzle, so the pressure feeding method using a pressure vessel is the only paint supply method.

A general high-pressure air spray gun having a spraying pressure of 300-350 kPa is used according to the present invention, in addition to a pressure-feeding system for supplying paint or the like through a paint hose using a paint tank or a paint pump. For air spray guns that branch the spray air from the spray gun and supply compressed air to the pressurized container to supply paint, etc., do not provide a check valve in the flow path for supplying pressurized air. The pressurized air is supplied to the pressurized container in synchronization with the opening of the air valve that is interlocked with the trigger of the spray gun. Therefore,
When the trigger is returned and the air valve is closed, the pressurized air in the pressurized container is also exhausted from the tip of the spray gun and is not pressurized. Further, a vent valve or a safety valve is provided on the lid of the pressurizing container at a location separate from the pressurizing flow path.

When the pressurized air supply mechanism used in the above high pressure spray gun is adopted in the low pressure spray gun,
Since the pressure of the pressurized air that is branched and supplied from the spray air is low, it takes time for the pressurized air to fill the pressurized container, and even if the needle valve of the paint nozzle is opened, the paint immediately There is a deviation in the timing of not ejecting. In particular, when the amount of paint in the container is small, there is a problem that the delay in the ejection of paint is further increased.

FIG. 3 is a cross-sectional view of a main part of an internal mixing type low pressure spray gun which the applicant has marketed. A conventional example will be described with reference to FIG. The same components as those of the present invention will be described with the same reference numerals. The spray air main body 10 is provided with a spraying air flow passage 10a, and a pressurizing air flow passage 10b branched from the spray air flow passage 10a is formed into a paint joint 10
1. Pressurization is applied from the outer circumference of the paint suction pipe 22 through the pressurizing flow path 101a formed in parallel with the first paint flow path and from the inner peripheral clearance of the center through hole of the stem portion of the container lid 102 formed in a mushroom shape. It is supplied into the container 21. Inner recess 102 of container lid 102
a is a check valve plate 10 made of a resin plate such as nylon.
5 is airtightly fitted to the suction pipe 22, and the outer peripheral end of the check valve plate 105 tightly seals on the bottom surface of the inner recess 102a by the internal pressure of the pressurizing container 21 to function as a check valve.
The check valve plate 105 is made of a foam resin or the like having a relatively thick elasticity so that the check valve plate 105 can be fitted into the suction pipe 22 in an airtight manner.

There are some problems in the check valve mechanism using the check valve plate 105. One is the check valve plate 1
Since 05 is inside the pressure vessel 21, there is a problem that the valve cannot be opened due to adhesion of paint or the like. Another is that the check valve plate 105 is fixed so that the valve plate is relatively thick and the inner diameter is
The instability of the seat due to the smaller size on the relative side, etc., may cause variations in the pressurized air pressure. Furthermore, another problem is that in the case of hot spray in which paint is heated and sprayed, the check valve plate 105 is deformed by the heated organic solvent or organic solvent gas, and the problem of the check valve disappearing occurs. There was found.

By attaching a check valve mechanism to the pressurized air flow path, the pressurized air in the pressurized container is degassed before the material is replenished or at the end of the work, and then the container lid 102 is removed. For this deaeration, the deaeration valve set 106 is attached to the container lid 1.
02 is screwed on. The deaeration valve set 106 has a mounting valve and a valve seat formed in the deaeration valve main body 106a, and the knob 1
A valve 106d integral with 06b is pressed against the valve seat with a screw. And when deaeration, knob 10
By loosening 6b, the valve 106d moves upward, the valve is opened, and air is vented from the vent hole 106c. This deaeration valve set 106 is not necessary in a pressurized container without a check valve mechanism.

[0009]

A small-sized paint container is directly connected to a low-pressure air spray gun, and a mechanism for supplying pressurized air to a pressurized container for feeding and supplying the coating material in the container is sprayed. It was necessary to attach a non-return valve mechanism in order to provide stable ejection rate and quick response under low pressure of air, and the non-return valve structure attached in the conventional pressurized container There is instability in valve operation due to adhesion etc., there is a defect that the check valve effect is lost due to deformation of the check valve plate due to organic solvent or organic solvent gas, and a vent valve mechanism that was previously unnecessary Due to the complexity of the structure that must be newly provided, the above-mentioned problem is solved by integrating the check valve mechanism and the deaeration valve mechanism and attaching the check valve mechanism on the pressurized container lid. Pressurized air in the pressurized container of the low-pressure spray gun And to obtain a sheet mechanism.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to connecting a small paint container directly to the paint joint of a low pressure spray gun,
In a pressurized container of a low-pressure spray gun that supplies compressed air to the paint container to feed the coating material in the container to a spray gun, a pressurizing air joint set attached to a container lid is used to pressurize. A pressurized air supply mechanism for a low-pressure spray gun pressurized container in which a check valve that operates with low-pressure air is provided, and a degassing valve is provided in addition to the pressurized air joint set.

Further, the check valve attached to the container lid of the pressurizing container and arranged in the pressurizing air joint set mainly composed of the check valve main body and the deaeration valve main body has solvent resistance and heat resistance. Is a non-return valve that has a valve plate made of a thin plate material that has flexibility and flexibility, and is opened by bending the valve plate or dropping it with low pressure air for pressurization. The vent valve attached to the set is opened by the rotation of the check valve body that is screwed to the vent valve body.
It is a pressurized air supply mechanism for a low pressure spray gun pressurizing container that is vented through a vent hole that is drilled in the vent valve body.

[0012]

The operation will be described with reference to FIGS. 1 and 2. Spraying air flow path (10) of the spray gun body (10)
a pressurized air flow path (10b) branched from a) and perforated;
And a pressurized air joint (1), which will be described in detail later, which is screwed to the container lid (20) via the flexible tube (7).
Flow through the check valve (3) and the deaeration valve (4) to pressurize the coating material in the pressurizing container (21), and the suction pipe (22).
The coating material is pressure-fed and supplied to the coating material nozzle (11).

In the internal mixing type low pressure spray gun having the above structure, the pressure for feeding the coating material is set to the coating nozzle (1
The pressure must be equal to or higher than the pressure of the mixing chamber (14b) with the air blow formed in the central cap (14) of 1). Therefore, when the needle valve (15) is pulled, the pumping pressure in the paint nozzle (11) must always maintain the pumping pressure. If the pressurization from the pressurized air flow path is delayed, the paint will not be ejected even if the trigger is pulled until the inside of the pressurizing container (21) is pressurized, and the ejection delay is caused, which hinders the spraying work. It will be. Especially in the low pressure spray gun, the pressure of the air that pressurizes the paint container is
Because of the low pressure, the flow velocity of the air flow path is slow, and even a slight resistance of the air flow path requires time to press the paint material in the paint container, resulting in a delay in pressurization. Therefore, by arranging the check valve (3) in the air flow path and keeping the pressurizing pressure in the pressurizing container (21) constant, it is possible to relate to the opening and closing of the frequently operated needle valve (15). The purpose is to maintain the necessary pumping pressure at the tip of the paint nozzle. As a result, the pressurized air is filled in the pressurizing container (21) by maintaining the pressurizing pressure at a constant level by performing the air-blowing without spraying the paint at the beginning of spraying for several seconds.

The operation of the pressurized air joint set (1) screwed on the container lid (20) will be described with reference to the enlarged sectional views of FIGS. 2 (a) and 2 (b). The convex check valve (3), which is opened by the low pressure flow from the flow passage (2a) pierced in the check valve body (2), has a thin film valve plate (3a) and a valve guide (3b). And is slidably fitted in the center guide hole (2b) of the check valve body (2). The check valve (3) is supported by the deaeration valve (4) at an appropriate interval. When pressurized air flows in this configuration, the check valve (3) falls to the vent valve (4) side, and at the same time, the thin film valve plate (3a) bends downward and pressurizes from the bent gap. Air flows into the pressure vessel (21) side. Then, when the air valve of the spray gun is closed, the pressure above the check valve (3) is released to the outside, and when the pressure becomes very small, it is closed by the flexural elastic force of the check valve plate (3a). At the same time, the pressure in the pressurizing container (21) causes the valve plate (3a) to be pressed into close contact with the seat surface (2c) of the check valve body, so that the flow path (2a) of the check valve body is completely closed. Will be closed.

The vent valve (4) has a flow passage (4
a), a screw (4e) screwed to the check valve body (2) on the outer circumference of the vent valve (4), and a taper (4c). Then, with the valve taper (4b) on the outer circumference of the tip of the vent valve (4), the seat surface (5) of the vent valve body (5) is
It is threadedly joined to c) by the check valve body (2). A vent hole (5a) is bored in the side surface of the vent valve body (5). With this configuration, when the coating material is supplied, it is closed by the vent valve taper (4b), but the pressurized air in the pressurized container (21) at the time of removing the container lid (20) for replenishing the material, etc. When venting, the vent valve (4) is screwed and fixed to the check valve body (2). Therefore, by turning the check valve body (2), the seat surface (4b) of the vent valve (4) is rotated. ) Opens and the vent hole (5
Degassed from a).

Due to the above-mentioned structure and operation, the check valve (3) is made of a thin film, so that the compressed air can be supplied to the container lid (20) without any resistance. Since the organic solvent or the organic solvent gas in the pressurizing container (21) does not enter the check valve (3) by providing the stop valve, the check valve (3) may be stuck, deformed or damaged. Disappears. Further, since the deaeration valve (4) is provided side by side, the structure is simplified and a stable constant pressurizing pressure is maintained, and the ejection of the coating material is stabilized. Further, it is possible to obtain a responsive and rapid coating material supply mechanism which corresponds to the stop of the coating material injection in the trigger operation of the frequently operated spray gun.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view in which a pressure vessel for supplying a coating material is connected to an internal mixing type low pressure spray gun, and a pressure air joint set of the present invention is attached. Spray gun body 10
A paint nozzle 11 is screwed on. The paint nozzle 11
Two channels, a central air channel 11a and a pattern adjusting auxiliary air channel 11b, are bored in this. A flow path to the air cap 12 that communicates with the side air holes 12a at the corners is formed on the outer periphery of the paint nozzle 11. The air cap 12 is screwed to the spray gun body 10 by a cap cover 13. A separate center cap 14 is joined to the center of the air cap 12 by a taper so as to surround the paint nozzle 11.
2 is airtightly fitted through O-ring. A beak-shaped spray port 14 a is opened in the center cap 14. The needle valve 15 is pressed into the paint passage 11c of the paint nozzle 11 at the paint nozzle ejection port 11d by a spring arranged at the rear of the spray gun main body, and is taper-joined at the tip of the paint nozzle. By pulling the needle valve, The paint nozzle ejection port 11d is opened and closed to stop the ejection of the paint. The air passage 10a formed in the spray gun body 10 has two passages, not shown, of another air passage, and one air passage 10a is an air passage of the paint nozzle. To the center of the center cap 14 through the other side air holes 12a
Is airtightly branched into two channels. Then, the pattern shape and the pattern opening of the flat pattern are adjusted by adjusting the amount of air to the side air holes 12a with a pattern adjusting valve attached to the rear portion of the spray gun body 11.

In the above structure, the paint nozzle jetting port 11
The coating material jetted from d mixes with the compressed air jetted from the slit on the outer circumference of the paint nozzle inside the beak-shaped spray port of the center cap 14. By the so-called internal mixing formula,
A shearing force is applied to the coating material, and it is sprayed in a fan shape from a beak-shaped spray port. Therefore, in the internal mixing type atomization method, the mixing chamber 1 is discharged from the ejection port 11d of the paint nozzle 11.
Since the coating material must be jetted against the pressure in 4b, the coating material pressurized in the pressure vessel 21 is supplied.

The pressurized air supplied to the pressurized container 21 is branched from the air flow path 10a of the spray gun main body 10 and supplied from the pressurized air flow path 10b formed in the main body on the paint joint 17 side. , A ring-shaped joint 1 sandwiched between the spray gun body 10 and the paint joint 17.
A flexible tube 7 is attached to 8, and air is supplied to the pressure joint set 1, which will be described later in detail, through the flexible tube 7 and is supplied from the pressure joint set 1 to the pressure container 21.

The pressurizing container 21 includes a container lid 20 and a suction pipe 22.
Together with the cap nut 1 mounted by the mounting screw 24
At 9, the paint joint 17 is screwed. A lid fastening arm 25 on the stem portion of the container lid 20 formed in a mushroom shape,
A lid tightening cam 26 is attached. The pressure container 21 is operated by operating a manual lever (not shown) on the cam 26.
A lid tightening arm 25 hooked to a lid tightening pin 21a fixedly attached to the lid tightening cam 25 and a lid tightening cam 2
6, the container lid 20 is pressed against the pressure container 21 side. That is, the lid tightening arm 25 is rotatably attached to the stem portion of the container lid 20.
5 is formed with a U-shaped groove at a portion to be hooked to the lid fastening pin 21a, and the rotation of the arm 25 causes the pin 21 to rotate.
When the arm 25 is fixed by being hooked on a,
By rotating the cam 26, the container lid 20 is pressed downward by the inclined surface of the lid fastening cam 26.

On the upper surface of the container lid 20, the pressure joint set 1 of the present invention, which will be described in detail with reference to FIG. 2, is attached to a mushroom-shaped umbrella portion. A resin drip free 23 is fitted in the inner recess of the container lid 20. The drip-free 23 prevents the coating material in the container from invading the pressurizing joint set 1 portion and blocking the flow path even when the pressurizing container 21 is tilted during spraying work or is laid sideways. ing. A suction tube guide 27 seals pressurized air and prevents the coating material from penetrating the through hole into which the suction tube 22 of the stem of the container lid 20 is inserted.

The structure of the tip of the spray gun and the method of tightening the container lid 20 described above are not intended to limit the present invention, but are merely an explanation for helping understanding of the pressurized air supply mechanism of the present invention. Only.

FIG. 2 is an enlarged sectional view of the pressurized air joint set 1 of the present invention. FIG. 2 (a) shows a state in which the check valve 3 is set, and FIG. Stop valve 3
Shows the opened state. In FIG. 2, the flexible resin tube 7 is inserted into the bamboo shoot joint 6, the bamboo shoot joint 6 is fitted into the recess of the check valve body 2 via the O-ring 9, and the tube presser 8 is used to check the check valve. Body 2
It is screwed and fixed to. A plurality of flow paths 2a for introducing air from the flow path 6a of the bamboo shoot joint 6 into the check valve body 2 are formed around the center guide hole 2b of the check valve body 2. The film-shaped valve plate 3a of the check valve 3 is bent by the low-pressure air from the flow path 2a to open the valve.

The guide portion 3b of the check valve 3 having a convex shape is fitted into the central guide 2b to ensure the operational stability of the thin valve plate 3a. The check valve 3 is set so as to be placed on the upper surface of the deaeration valve 4, and the outer periphery of the valve plate 3a is in contact with the seat portion 2c of the check valve body as shown in FIG. A slight gap may be set between the portion 2c and the valve plate 3a. Then, the low-pressure pressurized air flows in through the above-mentioned gap or inflows the valve plate 3a by bending the valve plate 3a as shown in FIG. 2B. The check valve 3 is closed by the valve plate 3
The valve 3 is closed by the bending elastic force of a, or the valve 3 is pushed up and closed by the backflow pressure from the pressurizing container 21, and the closing of the valve is maintained by the internal pressure of the pressurizing container. When the coating material is used and the internal pressure of the container decreases, the check valve 3 supplies the pressurized air. The setting position of this check valve is
The taper portion 4c is fixed to the check valve main body 2 by screwing at a proper position.

The vent valve 4 has a through hole 4a formed in the center thereof, and a lateral hole 4d is provided immediately below the upper surface for receiving the check valve 3 to allow pressurized air to flow therein, thereby forming a taper sheet of the vent valve body 5. It is joined to the surface 5c and is airtightly screwed and pressed. When the container lid 20 is removed, such as when the coating material is replenished, the check valve body 2 that is screwed to rotate the check valve body 2 is opened in order to release the pressurized air, and the deaeration valve 4 is opened. The air is exhausted from the air vent hole 5a formed in the side surface of the air valve body 5. By means of a lower screw 5b of the degassing valve body 5, a pressurized air joint set is screwed and fixed to the container lid 20 by an adhesive agent or the like.

[0026]

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

By using a pressurizing air joint set in which a check valve mechanism and a deaeration valve mechanism are integrated as a pressurizing air supply mechanism, the structure is simplified and a relatively inexpensive mass-production type pressurizer is conventionally used. A container can be provided.

By mounting the pressurized air joint set on the container lid, the risk of deformation and damage of the check valve is avoided, and hot spray coating for heating the organic solvent type coating material is also possible. It becomes a pressurized container that can be used.

Further, by providing the check valve, the low-pressure spray gun with a pressurized container has a quick response to the frequent spray gun trigger operation, which corresponds to the stop of the paint injection, and the spray gun operation is good. Is obtained.

By making the check valve a thin film-like valve plate, low pressure pressurized air is supplied with almost no resistance, and the pressure difference between the air pressure branched from the blown air and the pressure in the container is reduced. In addition, since the pressure inside the pressure vessel is stable and constant, the spray amount of the coating material is stable, and the low-pressure spray gun is easy to control the spray amount of the coating material.

Further, the pressurized air supply mechanism is integrated with the pressurized air joint set and the check valve body is rotated to vent the air, thereby providing a pressurized air supply mechanism which is easy to handle.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the entire configuration in which a pressurized container is connected to an internal mixing low-pressure spray gun and the pressurized air joint set of the present invention is attached on a container lid.

FIG. 2 (a) is an enlarged cross-sectional view showing an initial set state of the check valve in the pressurized air joint set. (B) An enlarged cross-sectional view showing a state where the check valve is opened by the pressurized air in the pressurized air joint set.

FIG. 3 is a cross-sectional view of an essential part of the entire configuration showing a check valve mechanism and a deaeration valve mechanism of a conventional internal mixing low-pressure spray gun.

[Explanation of symbols]

 1 Pressurized Air Joint Set 2 Check Valve Body 3 Check Valve 3a Valve Plate 3b Valve Guide 4 Venting Valve 5 Venting Valve Body 7 Flexible Tube 10 Spray Gun Body 11 Paint Nozzle 12 Air Cap 14 Center Cap 15 Needle Valve 17 Paint joint 20 Container lid 21 Pressurized container 21a Lid clamping pin 22 Suction tube 25 Lid clamping arm 26 Lid clamping cam

Claims (3)

[Claims] 1. A low-pressure spray gun, in which a small paint container is directly connected to a paint joint of the low-pressure spray gun, compressed air is supplied to the paint container, and the coating material in the container is pressure-fed to the spray gun. In the pressure vessel, the vessel lid (2
0) A check valve (3) which is operated by low pressure air for pressurization is arranged in a pressurized air joint set (1) additionally attached to the pressurized air joint set (1), and an exhaust valve (3) is provided in the pressurized air joint set (1). 4) A pressurized air supply mechanism for a low-pressure spray gun pressurized container equipped with. 2. A pressurized air joint set (1) which is attached to a container lid (20) of a pressurized container and mainly comprises a check valve body (2) and a deaeration valve body (5). The check valve (3) provided is composed of a valve plate made of a thin plate material having solvent resistance, heat resistance, and flexural elasticity, and the valve plate is dropped by low pressure air for pressurization or The pressurized air supply mechanism for a low pressure spray gun pressure vessel according to claim 1, wherein the plate is a check valve that is opened by bending. 3. A pressurized air joint set (1) mainly composed of a check valve body (2) and a deaeration valve body (5).
The exhaust valve (4) attached to the exhaust valve (4) is opened by rotation of the check valve body (2) screwed to the exhaust valve body (5) to open the seat surface (4b) of the exhaust valve (4). The pressurized air supply mechanism for the low pressure spray gun pressure vessel according to claim 1, wherein the air is exhausted through a vent hole (5a) formed in the vent valve body (5).