JP2000005647A - Spray gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray gun capable of accurately regulating the spray amt. of liquid without causing a liquid leak. SOLUTION: A spray gun 1 ejecting liquid from a nozzle 3 and mixing the same with compressed air to spray the liquid is separately provided with a low rate regulating mechanism 6 regulating the supply amt. of the liquid to the nozzle 3 and a liquid stop mechanism 7 capable of prescribing the supply of the liquid to the nozzle 3. Since the liquid amt. regulating mechanism 6 and the liquid stop mechanism 7 are separately provided, even if the liquid stop mechanism 7 is constituted so that a liquid leak is not generated under a sivere use condition such as intermittent spraying or the like, the accuracy of the regulation of a liquid amt. is not lost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray gun which sprays a liquid by jetting a liquid from a nozzle and mixes the compressed air with the spray, for example, spraying a paint on a vehicle or the like, waterproofing a cloth or the like. It can be used as a spray gun used for spraying agents.

[0002]

2. Description of the Related Art Conventionally, a two-fluid system type spray gun which sprays a liquid by spraying a liquid from a nozzle and mixing it with compressed air has been used in the coating of vehicles, waterproofing of fabrics and the like. I have. Such a two-fluid system type spray gun is capable of spraying a liquid in the form of a mist by mixing the liquid with air, so that the spray particles can be made finer and the spray particle diameter can be arbitrarily changed. There are various advantages such as easy intermittent and repeated operations.

As a conventional spray gun, for example, a spray gun 101 as shown in FIG. 4 is known. The spray gun 101 includes a cylindrical gun body 2, a nozzle 3 provided on the tip side of the gun body 2, a cap 4 for holding the nozzle 3, and a needle valve 105 inserted into the nozzle 3 hole 31. And a liquid amount adjusting mechanism 6 provided on the rear end side of the gun body 2. And
The cap 4 is directly screwed with the gun body 2, and the liquid amount adjusting mechanism 6
Is screwed in through a bush 64 so that the nozzle 3
The needle valve 105 is housed and integrated in the space inside the cylindrical shape of the gun body 2.

[0004] In the gun body 2, a valve insertion portion 21 into which the needle valve 105 is inserted is formed substantially at the center of the space inside the cylinder, and compressed air is introduced outside the valve insertion portion 21. Air introduction part 22 is formed. And on the lower side of the gun body 2 in FIG.
A liquid inlet 23 into which a liquid such as paint is injected and an air inlet 24 into which compressed air is injected are formed. The liquid inlet 23 is connected to the valve insertion portion 21, and the air inlet 24 is connected to the air inlet 22. Communicating.

[0005] The needle valve 105 is provided with a valve body 151 inserted into the above-described valve insertion portion 21 and a needle 152 provided on the distal end side of the valve body 151 and having a tip portion gradually reduced in diameter inserted into the nozzle hole 31. And a pressure receiving portion 153 provided on the rear end side of the valve body 151 so as to be in contact with the inner peripheral surface of the air introduction portion 22 and receiving the internal pressure of the air introduction portion 22. The liquid volume adjustment mechanism 6
It has an adjusting portion main body 61 whose rear end portion is closed and the leading end is screwed with the bush 64, and a coil spring 63 housed inside the adjusting portion main body 61 and biasing the needle valve 105 described above. .

[0006] The conventional spray gun 10 having such a configuration is described.
In 1, the liquid can be supplied to and stopped from the nozzle 3 by moving the needle valve 105 in the extending direction of the nozzle hole 31. That is, the needle valve 1
In a state in which the nozzle 05 has advanced, the inner peripheral surface of the nozzle hole 31 and the outer peripheral surface of the tip portion of the needle 152 whose diameter decreases are in abutment, and the supply of liquid to the nozzle 3 is regulated. Needle valve 105
Is retracted, the nozzle hole 31 and the needle 1
A gap is formed between the nozzles 52, and the liquid is supplied to the nozzle 3 from the gap.

[0007] Further, the amount of liquid supplied to the nozzle 3 can be adjusted by defining such a retracted position of the needle valve 105 by the adjusting section main body 61. That is, the adjusting portion main body 61 of the liquid amount adjusting mechanism 6 and the bush 6
When the screwing position with the needle valve 4 is changed, the distal end portion of the adjusting portion main body 61 moves along the direction in which the needle valve 5 advances and retreats. Then, when the compressed air is supplied to the air introduction unit 22, the pressure receiving unit 153 is pressed, and the needle valve 105 is retracted until it comes into contact with the distal end portion of the adjustment unit main body 61. Therefore, the adjusting unit main body 6 that defines the retracted position of the needle valve 105
1 is adjusted, the nozzle hole 31 of the needle 152 is adjusted.
The position of the liquid supplied to the nozzle 3 can be adjusted by changing the gap between the needle 152 and the nozzle hole 31 when compressed air is introduced.

[0008]

However, the above-described liquid stopping mechanism for injecting and stopping liquid by inserting the needle 152 into the nozzle hole 31 has the following problems. That is, in such a conventional liquid stopping mechanism, the liquid is stopped by contact between the metal of the needle 152 and the metal of the nozzle hole 31. Therefore, if liquid injection and liquid stop are frequently repeated, such as intermittent spraying, the needle 1
There is a problem that the liquid leakage may occur due to wear or damage of the nozzle 52 or the nozzle hole 31.

Therefore, the needle 152 of the nozzle hole 31
A method is also conceivable in which an elastic body is interposed between the abutting surface of the needle 152 and the abutting portion of the needle 152, thereby preventing the abrasion of the needle 152 or the nozzle hole 31. However, in the above-described conventional spray gun 101, the amount of liquid to be sprayed is adjusted by using the change in the gap between the needle 152 and the nozzle hole 31. Therefore, when such an elastic body is interposed, the amount of liquid to be sprayed is adjusted. There is a problem that it cannot be performed accurately.

An object of the present invention is to prevent a liquid from leaking in a spray gun which sprays the liquid by jetting the liquid from a nozzle and mixing the compressed air with the compressed air.
It is an object of the present invention to provide a spray gun capable of accurately adjusting the amount of liquid to be sprayed.

[0011]

In order to achieve the above object, a spray gun according to the present invention is a spray gun for spraying a liquid by ejecting the liquid from a nozzle and mixing the compressed liquid with compressed air. A liquid amount adjusting mechanism for adjusting the liquid supply amount to the nozzle and a liquid stopping mechanism for regulating the liquid supply to the nozzle are provided separately. Here, "the liquid amount adjusting mechanism and the liquid stopping mechanism are separately provided" means, for example, a portion for adjusting the liquid amount by changing a gap between the nozzle hole and the needle, and a liquid to the nozzle. Refers to a configuration in which a valve part that can regulate the supply of liquid is separately provided, and it is possible to provide a liquid amount adjusting mechanism and a liquid stopping mechanism in a spray gun in parallel or in series. it can.

According to the present invention, since the liquid amount adjusting mechanism and the liquid stopping mechanism are provided separately, the liquid stopping mechanism is configured to prevent liquid leakage under severe use conditions such as intermittent spraying. Also, the accuracy of the liquid volume adjustment is not impaired. In addition, since the liquid amount adjusting mechanism is separate from the liquid stopping mechanism, it is possible to increase the precision of the liquid amount adjustment by slightly changing the shape of the tip of the needle.

In the above, the above-mentioned liquid amount adjusting mechanism
The tip whose diameter gradually decreases is inserted into the hole of the nozzle, and the needle includes a needle capable of adjusting the amount of liquid by adjusting the amount of insertion. The above-described liquid stopping mechanism is configured to supply the liquid to the nozzle. It is preferable to include a valve that can be regulated, and that the needle and the valve are arranged coaxially. That is, since the needle and the valve are arranged coaxially, it is possible to coaxially arrange the needle advancing / retracting mechanism and the valve advancing / retreating mechanism accompanying the needle and the valve, and a liquid amount adjusting mechanism and a liquid stopping mechanism are provided. The size of the spray gun can be reduced.

The above-mentioned valve preferably includes a valve body which is a movable portion, and a valve seat with which the valve body abuts, and it is preferable to adopt a valve in which the valve seat is made of an elastic material. Here, as the elastic body, it is preferable to adopt a material that does not cause abrasion, scratches, etc. on the valve body even when the valve body made of metal comes into contact with the elastic body. it can. That is, since the valve seat is made of an elastic body, even if the metal valve main body comes into contact with the metal valve main body, the metal valve main body will not be worn or damaged. Further, when a predetermined urging force acts on the valve body to abut against the valve seat, the valve seat is deformed by the urging force, so that the liquid can be reliably stopped by the valve.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. The same reference numerals are given to the same or similar parts as the already described members or parts, and the description thereof will be omitted or simplified. In the above-described conventional spray gun 101, the advance / retreat position of the needle 152 of the needle valve 105 is defined by the liquid amount adjusting mechanism 6, and the amount of insertion of the needle 152 into the nozzle hole 31 is changed to adjust the amount of liquid. When the gun 101 is stopped, the needle 152 comes into contact with the inner surface of the nozzle hole 31 to regulate the supply of the liquid to the nozzle 3 and stop the liquid of the spray gun 101.

On the other hand, as shown in FIG. 1, the spray gun 1 according to the first embodiment of the present invention includes a liquid amount adjusting mechanism 6 and a liquid stopping mechanism 7 which are separately provided with the nozzle 3.
In that the nozzle holes 31 are arranged coaxially along the extending direction. That is, the spray gun 1 of this example
As shown in FIG. 1, is configured to include a gun body 2, a nozzle 3, a cap 4, a liquid amount adjusting mechanism 6, and a liquid stopping mechanism 7, and an air injection port 24 formed in the gun body 2 includes:
A compressor 14 is connected via a hose 11, a two-port solenoid valve 12, and a pressure reducing valve 13. On the other hand, a tank 16 for storing a liquid is connected to the liquid inlet 23 via a hose 15, and a hose 17 is further connected to the tank 16. The hose 17 is connected to the two-port solenoid valve 1.
2 and the pressure reducing valve 13 are connected to the hose 11.

The liquid amount adjusting mechanism 6 includes an adjusting portion main body 61 formed of a cylindrical body, a needle 62 and a coil spring 63 inserted into the cylindrical body of the adjusting portion main body 61, and a bush 64. The needle 62 is fixed to the adjusting section main body 61 by a set screw 65. The liquid stopping mechanism 7 includes a valve including a valve body 71 and a valve seat 72, and the valve body 71 is inserted into the valve insertion portion 21 of the gun body 2. This valve body 71
A needle insertion portion 711 into which the needle 62 is inserted is formed in a substantially central portion of the valve body 71 along a direction in which the needle 62 extends. A pressure receiving portion 712 is formed to be in contact with the inner peripheral surface inside the cylinder of the main body 2.

The valve seat 72 is made of silicone elastic rubber and has a hole 721 formed in the center thereof.
The needle 62 is inserted therein. In addition, packing 81 is arranged on the screw portion of the gun body 2 and the cap 4, the rear end portion of the needle insertion portion 711, and the outer peripheral portion of the pressure receiving portion 712 of the valve body 71. A Teflon sheet 82 is disposed in a closed portion of the main body 61. As a result, the air tightness of the air introduction part 22 and the needle insertion part 711 of the gun body 2 is ensured.

Next, the operation of the spray gun 1 having the above configuration will be described below. First, the liquid amount of the spray gun 1 is adjusted by the liquid amount adjusting mechanism 6. Specifically, by changing the screwing position between the adjusting portion main body 61 and the bush 64 and adjusting the advance / retreat position of the needle 62 with respect to the nozzle hole 31, the nozzle hole 3
The amount of liquid supplied from the gap between 1 and the needle 62 is set to a predetermined value. Next, when the compressor 14 is driven in a state where the pressure reducing valve 13 is closed and the two-port solenoid valve 12 is opened, compressed air is sent out from the compressor 14, and a part of the compressed air is sent to the air inlet 24 through the hose 11. Supplied. Another part of the compressed air is supplied into the tank 16, whereby the inside of the tank 16 is pressurized, and the liquid is supplied to the liquid inlet 23 via the hose 15.

The pressure of the injected compressed air pressurizes the air introduction section 22, and the pressure increase causes the pressure receiving section 7.
1 is pushed to the right in FIG. 1, and as shown in FIG. 2, the valve body 71 is retracted until it comes into contact with the distal end portion of the adjusting section body 61 of the liquid amount adjusting mechanism 6. When the valve body 71 is retracted, the coil spring 63 inside the adjustment unit body 61 is urged in the compression direction. The liquid supplied from the liquid inlet 23 flows through the inside of the valve insertion portion 21, and the needle 62 and the nozzle hole 31
The liquid is supplied to the nozzle 3 from the gap defined by:

The compressed air supplied to the air introduction part 22 is supplied to a space between the nozzle 3 and the cap 4. Then, the liquid supplied to the nozzle 3 is
Is mixed with compressed air in the vicinity of the hole formed at the tip of the nozzle, and is ejected in the form of a mist. When stopping the liquid spraying, when the two-port solenoid valve 12 is closed, the air pressure in the hoses 11, 15, 17 drops to atmospheric pressure, and accordingly, the pressure inside the air inlet 22 also drops to atmospheric pressure. Then, the valve body 71 is advanced by the urging force of the coil spring 63 urged in the compression direction until the distal end portion of the valve body 71 comes into contact with the valve seat 72, and the valve seat 72 is elastically deformed and the valve body 71 is deformed. And regulates the supply of liquid to the nozzle 3.

According to the first embodiment as described above, the following effects can be obtained. That is, since the liquid amount adjusting mechanism 6 and the liquid stopping mechanism 7 are provided separately, the valve main body 71 and the valve seat 72 are provided so that the liquid stopping mechanism 7 can withstand intermittent spraying or the like.
, The accuracy of the liquid amount adjustment of the liquid amount adjustment mechanism 6 is not impaired. Further, by finely changing the shape of the tip of the needle 62, it is possible to achieve high precision in adjusting the liquid amount. Further, since the needle 62 and the valve body 71 are coaxially arranged along the direction in which the nozzle hole 31 extends, the mechanism for moving the needle 62 by the adjusting section body 61 and the mechanism for moving the valve by the pressure receiving section 712 and the coil spring 63. Can also be arranged coaxially, and the size of the spray gun 1 can be reduced.

Further, since the valve seat 72 constituting the valve is made of elastic rubber, the valve body 71 is not worn, scratched or the like. Further, since the valve body 71 and the valve seat 72 can be brought into contact with each other in a state of being in close contact with each other, the liquid can be reliably stopped by the valve. Since the needle 62 is fixed to the adjusting section main body 61 by the set screw 65, the needle 62
Even if damage occurs, the set screw 65 is loosened, so that only the needle 62 is removed, and maintenance can be performed with minimum necessary member replacement. Further, since the adjusting portion main body 61 is connected to the gun main body 2 via the bush 64, the air introducing portion 22 and the like inside the gun main body 2 can be cleaned by removing the bush 64 from the gun main body 2. Thus, maintenance of the spray gun 1 can be facilitated.

Next, a spray gun according to a second embodiment of the present invention will be described. In the spray gun 1 according to the first embodiment described above, the liquid amount adjusting mechanism 6 and the liquid stopping mechanism 7
Were arranged coaxially. On the other hand, the spray gun 201 according to the second embodiment is shown in FIGS.
As shown in the figure, the liquid amount adjusting mechanism 206 and the liquid stopping mechanism 2
07 are arranged in parallel, so that the gun body 202 is also formed in a rectangular parallelepiped shape.

That is, the spray gun 201 is
As shown in (A) and (B), a rectangular parallelepiped gun body 20 is provided.
2, a nozzle 3 and a cap 4 provided on the front side of the gun body 202, a liquid stopping mechanism 207 provided on the rear side, and a liquid amount adjusting mechanism provided in parallel with the liquid stopping mechanism 207. 206.
A liquid inlet 23 and an air inlet 24 are formed on the upper surface of the gun body 202. This liquid inlet 23 is
The liquid amount adjusting mechanism 206 is housed and communicates with the liquid introduction unit 231 for introducing the injection liquid.

The liquid introducing section 231 is configured to communicate with a space for accommodating the nozzle 3 through a flow path 232 provided at the bottom thereof so as to supply the injected liquid to the accommodating space for the nozzle 3. I have. The air inlet 24 is dug down to the lower part of the gun body 202 and
7 is in communication with the air introduction unit 22 in which the pressure receiving unit 712 is provided.

The liquid amount adjusting mechanism 206 includes an adjusting section main body 261 screwed to the gun main body 202 via the bush 64.
And a needle 262 having a tapered portion 262A whose tip gradually decreases in diameter, and a biasing means 266 provided at an intermediate portion of the needle 262. The urging means 266 is engaged with a projection 262B projecting radially outward from an intermediate portion of the needle 262, and is arranged to urge the needle 262 to the left in FIG. Further, the tapered portion 262A is inserted into a communication hole 233 that connects the liquid inlet 23 and the liquid introduction portion 231.
When the advance / retreat position of the needle 262A is changed, the tapered portion 2
The gap between 62A and the communication hole 233 changes so that the amount of liquid supplied from the liquid inlet 23 can be adjusted.

Such a liquid amount adjusting mechanism 206 operates as follows. That is, the liquid supplied from the liquid inlet 23 at a predetermined pressure is supplied to the needle 26 by the pressure.
2 is pushed down to the right in FIG. The needle 262 is retracted to a position defined by the liquid amount adjusting mechanism 261, and a liquid amount corresponding to a gap amount between the tapered portion 262 </ b> A and the communication hole 233 at that time is supplied to the liquid introduction portion 231.
Is supplied with a predetermined amount of liquid. On the other hand, when the supply of the liquid from the liquid inlet 23 is stopped, the needle 262 is pushed to the left by the urging means 266, and stops moving forward and backward so as to close the communication hole 233 with the tapered portion 262A.

The liquid stopping mechanism 207 includes a valve composed of a valve body 271 and a valve seat 72, and a pressure receiving section 712 disposed in the air introduction section 22;
1 and includes a coil spring 63 for urging the valve body 271 to the left, and a case 273 for housing the coil spring 63 therein. The operation of the liquid stopping mechanism 207 and the mixing and spraying of the compressed air supplied from the air introduction unit 24 and the liquid supplied to the nozzle 3 are substantially the same as those in the first embodiment described above, and thus description thereof will be omitted. .

According to the spray gun 201 according to the second embodiment, as described in the first embodiment,
In addition to the effects of, there are the following effects. That is, since the needle of the liquid amount adjusting mechanism 206 is urged to the left by the urging means 266, if the liquid amount supply from the liquid inlet 23 is stopped, the communication hole 2 is formed by the tapered portion 262A.
33 can be closed. Therefore, in addition to the liquid stopping by the liquid stopping mechanism 207, the liquid stopping by the liquid amount adjusting mechanism 206 is also performed, so that the liquid leakage from the spray gun 201 can be more reliably prevented. Further, since the liquid amount adjusting mechanism 206 is provided in parallel with the liquid stopping mechanism 207, a hole for inserting a needle into the valve main body 271 like the valve main body 71 of the spray gun 1 according to the first embodiment is provided. There is no need to provide it, and the structure of the valve body 271 can be simplified.

The present invention is not limited to the above-described embodiment, but includes the following modifications. That is, in the spray gun 1 of the embodiment,
The valve seat 72 constituting the valve is made of elastic rubber. However, the present invention is not limited to this, and a valve seat made of a synthetic resin such as polypropylene may be adopted. In addition, specific structures, shapes, and the like at the time of carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.

[0032]

According to the present invention as described above, since the liquid amount adjusting mechanism and the liquid stopping mechanism are provided separately, liquid leakage may occur under severe use conditions such as intermittent spraying of the liquid stopping mechanism. Even if the configuration is not performed, the accuracy of the liquid volume adjustment is not impaired.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a spray gun according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a state during operation of the spray gun according to the embodiment.

FIG. 3 is a cross-sectional view and a plan view illustrating a structure of a spray gun according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a structure of a conventional spray gun.

[Explanation of symbols]

 3 Nozzle 1, 201 Spray gun 6, 206 Liquid amount adjusting mechanism 7, 207 Liquid stopping mechanism 62, 262 Needle 31 Nozzle hole 71, 271 Valve body 72 Valve seat

Claims (3)

[Claims] 1. A spray gun for spraying a liquid by ejecting the liquid from a nozzle and mixing the compressed air with the compressed air, wherein a liquid amount adjusting mechanism for adjusting a liquid supply amount to the nozzle;
A spray gun, characterized in that a liquid stopping mechanism capable of restricting liquid supply to the nozzle is provided separately. 2. The spray gun according to claim 1, wherein the liquid amount adjusting mechanism is configured such that a tip having a gradually decreasing diameter is inserted into a hole of the nozzle, and the liquid amount can be adjusted by adjusting the insertion amount. The liquid stopping mechanism is configured to include a valve capable of restricting the supply of the liquid to the nozzle, and the needle and the valve are coaxially arranged. gun. 3. The spray gun according to claim 2, wherein the valve includes a valve body which is a movable part, and a valve seat with which the valve body abuts, and the valve seat is made of an elastic body. A spray gun.